Sleep Disorders in Neurology E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 709

Veröffentlichungsjahr: 2018

Beschreibung

The acclaimed guide to quickly and confidently diagnosing and treating sleep disorders in neurological disease—now with more algorithms and tables

The diagnosis and treatment of sleep disorders can be extremely challenging for physicians, especially when there is underlying neurological disease. In addition to the primary sleep disorders, there is a growing clinical interest in sleep disturbances associated with common neurological disorders such as Parkinson's disease. This updated and expanded edition of the critically acclaimed Sleep Disorders in Neurology: A Practical Approach provides doctors with expert recommendations and clear guidance on identifying sleep disorders in patients suffering from neurological diseases and providing effective treatment plans.

In creating this Second Edition doctors Overeem and Reading made every effort to further enhance the practical approach of the first edition by adding additional algorithms and tables to assist physicians in more rapid decision making. In addition, they expanded the content to include greater coverage of primary sleep disorders. Classification and diagnosis chapters have been revamped to follow the 3^rd International Classification of Sleep Disorders.

• Offers physicians, with a practical approach to diagnosing and treating complex sleep disorders
• Draws on the expertise of neurologists who specialize in the disorders under discussion
• Features quick-access algorithms that help physicians rapidly diagnose and treat primary and secondary sleep disorders with confidence
• Provides guidance on when to consult a sleep specialist in managing a particular sleep disorder and
• Written by a multinational author team who provide a wider perspective and range of clinical experience

Sleep Disorders in Neurology: A Practical Approach, Second Edition is an essential resource for sleep medicine specialists, as well as clinicians and health care professionals not specifically trained in sleep medicine, but who nevertheless need to manage neurologically damaged patients with increasingly recognized sleep/wake disturbances.

Leseprobe

Table of Contents

Cover

Preface

In the Second Edition

Part One: General Sleep Medicine

1 The Sleep History

Introduction

Excessive Daytime Sleepiness

Insomnia

Nocturnal Disturbances

Conclusions

References

2 Polysomnography

Introduction

The Use of Polysomnography: Considerations and Indications

Standardisation of Video‐polysomnography

Scoring Sleep Stages

Sleep Related Movement Patterns

Sound Registration

Cardiac Function

Respiratory Scoring

A General Approach to Analysis and Interpretation

Some Additional Pointers and Pitfalls

References

Further Reading

3 Daytime Tests for Sleepiness and Vigilance

Introduction

The MSLT

The MWT

Sustained Attention to Response Task

Normative Data

Diagnostic Criteria

Recommendations for Use and Interpretation

References

4 Diagnostic Strategies and Classification

Introduction

Classifications

Sleep Questionnaires

Reaching a Diagnosis

References

5 Pharmacological Treatment of Insomnia and Parasomnias

Introduction

Sleep‐onset and Sleep‐maintenance Insomnia

Parasomnias

References

6 Pharmacological Treatment of Excessive Daytime Sleepiness

Introduction

General Aspects of Treatment

Indications

Amphetamine Derivatives

Modafinil

Caffeine

Sodium Oxybate

Pitolisant

Selegiline

Mazindol

Alerting Antidepressants

Acknowledgement

References

7 The Effects of Medication on Sleep and Wakefulness

Introduction

Neuropharmacology of Waking and Rapid Eye Movement Sleep

Neuropharmacology of Non‐REM Sleep

Appendix 7.A

Further Reading

Part Two: Primary Sleep Disorders

8 Narcolepsy and Other Central Disorders of Hypersomnolence

Introduction

Diagnostic Categories

General Aspects of Symptoms, Diagnosis and Management

Narcolepsy

Idiopathic Hypersomnia

Kleine–Levin Syndrome

Insufficient Sleep Syndrome

References

9 Insomnia

Introduction

Insomnia in Neurology

Clinical Pathophysiology

Assessment of the Insomniac

Management of Insomnia

References

10 Sleep‐related Breathing Disorders

Sleep‐disordered Breathing

Obstructive Sleep Apnoea

Central Sleep Apnoea

Conclusions

References

11 Circadian Rhythm Sleep Disorders

Introduction

Changes in Circadian Rhythm with Age

Circadian Rhythm Sleep–Wake Disorders

History and Investigations

Sleep Diaries

Actigraphy

Polysomnography

Delayed Sleep Phase Syndrome

Advanced Sleep Phase Syndrome

Shift Work Disorder

Jet Lag Disorder – ‘East is a Beast, West is Best’.

Free Running Circadian Rhythm Disorder

Irregular Sleep–Wake Rhythm Disorder

Conclusion

References

12 Parasomnias and Their Differentiation from Epilepsy

Introduction

Epileptic and Non‐epileptic Conditions Presenting as ‘attacks’ from Sleep

Diagnosing Sleep‐related Attacks

Investigations

Video Analysis of Events

Conclusion

References

13 Restless Legs Syndrome and Periodic Limb Movement Disorder

Introduction

Clinical Aspects

Pathophysiological Aspects

Diagnostic Procedures

Management

References

Part Three: Sleep in Neurological Disorders

14 Sleep Disorders in Parkinson’s Disease and Other Parkinsonian Syndromes

Introduction

Clinical Epidemiology

Signs and Symptoms

Diagnostic Procedures

Management

Conclusions

References

15 Sleep in Dementia and Other Neurodegenerative Diseases

Introduction

Alzheimer’s Disease

Dementia with Lewy Bodies

Huntington’s Disease

Hereditary Ataxias

References

16 Myotonic Dystrophy

Introduction

Myotonic Dystrophy Type 1

Myotonic Dystrophy Type 2

References

17 Sleep Disorders in Neuromuscular Disease

Introduction

Sleep and Breathing

Initial Clinical Approach

Nocturnal Testing

Surrogate Markers of Blood Gases

Sleep Dysfunction in Specific Neuromuscular Diseases

Management of Sleep Dysfunction in Neuromuscular Disorders

References

18 Headache Disorders

Introduction

Epidemiology

Classification

Diagnostic Procedures

Management

Conclusions

References

19 Sleep Epilepsies

Introduction

The Influence of Sleep Stages on Seizures

Clinical Epidemiology

Clinical Features

Diagnostic Procedures

Management

References

20 Sleep–Wake Disorders Following Traumatic Brain Injury

Introduction

Clinical Epidemiology

Excessive Daytime Sleepiness

Pleiosomnia

Fatigue

Insomnia

Circadian Sleep–Wake Disorders

References

21 Sleep Disorders Associated with Stroke

Introduction

Clinical Presentation and Pathophysiological Relevance

Diagnosis and Treatment

References

22 Sleep Disorders in Multiple Sclerosis and Related Conditions

Introduction

Fatigue Versus Sleepiness

Clinical Assessment

Specific Sleep Disorders in MS and Management Options

Secondary Narcolepsy in MS and Neuromyelitis Optica

References

23 Tumours and Paraneoplastic Syndromes

Sleep in Patients with Systemic Tumours

Sleep in Patients with Brain Tumors

Sleep in Paraneoplastic Syndromes

References

Index

End User License Agreement

List of Tables

Chapter 02

Table 2.1 Recommended signals to be obtained during polysomnogram recording, according to the AASM manual.

Table 2.2 Summary of characteristics used to identify sleep stages.

Table 2.3 AASM criteria for scoring of respiratory events.

Chapter 03

Table 3.1 Guideline from the American Academy of Sleep Medicine for the performance of the MSLT.

Table 3.2 Guideline from the American Academy of Sleep Medicine for the performance of the MWT.

Table 3.3 Recommendations for the SART protocol.

Chapter 04

Table 4.1 Main diagnostic entities in the ICSD‐3

.

Table 4.2 Sleep disorders classified in the ICD‐10 as ‘neurological’, together with neurological diseases that are very often accompanied by sleep disturbances; not all of which are mentioned in ICSD‐3

.

Table 4.3 Questionnaires often used in sleep medicine.

Chapter 05

Table 5.1 Benzodiazepines and benzodiazepine receptor‐agonist (‘z’) hypnotic drugs.

Chapter 08

Table 8.1 Hypersomnias of central origin, according to ICSD‐3.

Table 8.2 Topics to cover in the clinical interview.

Chapter 09

Table 9.1 ICSD‐3 criteria for chronic insomnia disorder.

Table 9.2 The insomnia history.

Table 9.3 Tips, strategies and psycho‐education to improve sleep hygiene.

Chapter 12

Table 12.1 Summary of clinical and EEG/polysomnographic features of NFLE/SHE.

Table 12.2 Key points to clarify in the history.

Chapter 13

Table 13.1 Diagnostic criteria for restless legs syndrome according to ICSD‐3.

Table 13.2 Clinical testing for restless legs syndrome.

Table 13.3 Diagnostic criteria for periodic limb movement disorder.

Table 13.4 Definition of PLMS according to the American Academy of Sleep Medicine [4].

Table 13.5 Non‐ergot dopamine agonists for the treatment of restless legs syndrome.

Table 13.6 Key features of augmentation.

Table 13.7 Opioids for the treatment of restless legs syndrome. With the exception of oxycodone/naloxone opioids are not approved for RLS therapy in Europe.

Chapter 14

Table 14.1 Some relevant probes to assess sleep problems in Parkinson's disease and parkinsonian syndrome.

Table 14.2 Abnormal findings on polysomnography and Multiple Sleep Latency Test in Parkinson's disease and parkinsonian syndrome.

Table 14.3 Management suggestions for sleep problems in Parkinson's disease patients.

Chapter 15

Table 15.1 Studies evaluating the frequency of restless legs syndrome in hereditary ataxias.

Chapter 16

Table 16.1 Clinical manifestations in the myotonic dystrophies.

Chapter 17

Table 17.1 Some signs and symptoms of sleep‐disordered breathing in neuromuscular diseases.

Table 17.2 Management options for sleep dysfunction in neuromuscular diseases (for details, see text).

Table 17.3 Suggested criteria guiding the initiation of nocturnal non‐invasive positive pressure ventilation in neuromuscular disorders.

Chapter 18

Table 18.1 International Headache Society diagnostic criteria [3].

Table 18.2 Headache practitioner’s brief sleep questionnaire.

Chapter 20

Table 20.1 Useful ‘probes’ for sleep–wake disturbances after traumatic brain injury.

Chapter 21

Table 21.1

Effect of continuous positive airway pressure after stroke.

Table 21.2 Summary of diagnostics and treatment of sleep–wake disorders following stroke.

Chapter 23

Table 23.1 Sleep disturbances recognised in paraneoplastic syndromes.

Table 23.2 Studies reporting excessive daytime sleepiness in patients with paraneoplastic anti‐Ma2 encephalitis.

List of Illustrations

Chapter 01

Figure 1.1 Algorithm outlining a diagnostic approach to some of the common causes of primary and secondary insomnia that might present to neurologists.

Chapter 02

Figure 2.1 Polysomnogram screenshot, with a time base of 30 seconds on the upper panel and 3 minutes for the polygraphic channels, during stage R. The lower two channels are additional EMG recordings of the flexor digitorum superficialis muscles of the arm (EMG1: right FDS; EMG2: left FDS). The FDS channels clearly show abundant tonic and phasic activity indicating REM sleep without atonia fitting with an RBD diagnosis. Note that the chin EMG and standard tibalis EMG channels (Leg/R and Leg/L) show much less activity, illustrating the usefulness of adding extra EMG leads when suspecting RBD.

Figure 2.2 Trend analysis in position‐dependent obstructive sleep apnoea. Nearly all breathing events occur in supine position (“Back”), including snoring.

Figure 2.3 Polysomnogram recording with a time base of 5 minutes per page. The leg EMG channels show several PLMs. Importantly, the PLMs are followed by arousals as shown in the EEG derivations as well as indicated by repeated transient increases in heart rate.

Chapter 04

Figure 4.1 Polysomnography results of the patient described in Case 3.

Chapter 05

Figure 5.1 Graphic depiction of plasma levels of some typical hypnotic drugs, taken at 23:00 hours. The depth of shading corresponds to plasma levels.

Chapter 06

Figure 6.1 Schematic diagram showing diagnostic and therapeutic steps and considerations when dealing with excessive daytime sleepiness.

Chapter 07

Figure 7.1 During wakefulness, brainstem ascending arousal systems activate the brain by stimulation of thalamocortical transmission and of attentional processes in frontal regions, which also leads to behavioural expressions (open white arrows). The activities of different stimulating neurotransmitter systems originating in specific brainstem nuclei (including noradrenergic, dopaminergic, histaminergic and cholinergic neurons) are modulated by peptidergic systems like orexin. In this way, wakefulness can be modified by physiological conditions and circadian rhythms. Brain regions: BF, basal forebrain; DRN, dorsal raphe nuclei; Hyp., hypothalamus; LC, locus coeruleus; LDT, laterodorsal tegmental nuclei; PPT, pedunculopontine tegmental nuclei; SCN, suprachiasmatic nucleus; TMN, tuberomammillary nucleus; VLPO, ventrolateral preoptic area; vPAG, ventral periaqueductal grey. Neurochemical: 5HT, serotonin; ACh, acetylcholine; DA, dopamine; Glu, glutamate; His, histamine; NA, noradrenaline; Orx, orexin.

Figure 7.2 Acetylcholine is not only involved in waking, but is also important in REM sleep. Cholinergic neurons facilitate thalamocortical activation, which produces some of the characteristic cortical rhythms observed in the sleep EEG. This cortical stimulation does not lead to behavioural manifestations, because the brainstem systems that mediate motor activity are inhibited during physiological REM sleep (arrows to transparent nuclei). Muscle tone is further reduced by glutamatergic projections from the sublaterodorsal nucleus in the pons. Brain regions: BF, basal forebrain; DRN, dorsal raphe nuclei; Hyp., hypothalamus; LC, locus coeruleus; LDT, laterodorsal tegmental nuclei; PC/PB, pericoeruleus and parabranchial nuclei; PPT, pedunculopontine tegmental nuclei; PVN, paraventricular nucleus; SCN, suprachiasmatic nucleus; SLD, sublaterodorsal nucleus; TMN, tuberomammillary nucleus; VLPO, ventrolateral preoptic area; vPAG, ventral periaqueductal grey. Neurochemical: ACh, acetylcholine; GABA, gamma‐aminobutyric acid; GLU, glutamate; Mel, melatonin.

Figure 7.3 The light–dark cycle has an influence on sleep and wakefulness through the suprachiasmatic nucleus. This ‘biological clock’ controls the rhythmicity of melatonin release in the pineal gland through polysynaptic pathways. During light, the SCN suppresses the hypothalamic paraventricular nucleus through GABA‐ergic projections. When night falls, the suprachiasmatic nucleus becomes less active and the paraventricular nucleus is disinhibited. This leads to melatonin production in the pineal gland, mediated by sympathetic (noradrenergic) nerve projections that originate in the superior cervical ganglion. Elevated melatonin levels (together with darkness and several neurochemical factors that are not shown in the figure) cause a disinhibition of the ventrolateral preoptic area of the anterior hypothalamus. This area is relatively inactive during wakefulness, but during sleep induction it exerts an inhibitory mainly GABA‐ergic drive (ventrolateral preoptic area with connecting arrows) on all major arousing neurotransmitter systems. Brain regions: DRN, dorsal raphe nuclei; Hyp., hypothalamus; LC, locus coeruleus; LDT, laterodorsal tegmental nuclei; PPT, pedunculopontine tegmental nuclei; PVN, paraventricular nucleus; SCG, superior cervical ganglion; SCN, suprachiasmatic nucleus; TMN, tuberomammillary nucleus; VLPO, ventrolateral preoptic area; vPAG, ventral periaqueductal grey. Neurochemical: GABA, gamma‐aminobutyric acid; Mel, melatonin; NA, noradrenaline.

Chapter 08

Figure 8.1 Typical narcolepsy findings on a polysomnographic recording starting at 16:00 throughout the night, followed by a MSLT. Several spontaneous sleep episodes can be seen in the afternoon and early evening. There is a fragmented sleep pattern, with several awakenings throughout the night. During all episodes of the MSLT stage 2 is reached, with a mean sleep latency of 4 minutes. In addition, there are three sleep‐onset REM periods (during episodes 1, 2 and 4). Finally, a spontaneous nap occurred between MSLT episodes 1 and 2.

Chapter 09

Figure 9.1 The ‘3‐P' model of insomnia. Predisposing, precipitating and perpetuating factors co‐contribute to the development of chronic insomnia.

Figure 9.2 The vicious circle of chronic insomnia.

Chapter 10

Figure 10.1 Polysomnogram overview showing severe obstructive sleep apnoea. Note: Respiratory events are associated with microarousals and oxygen desaturations. Sleep is fragmented and there are frequent body position changes.

Figure 10.2 Obstructive sleep apnoeas. Absent airflow with attenuated but ongoing respiratory movement indicating continuing effort.

Figure 10.3 Microarousal at termination of obstructive apnoea.

Figure 10.4 Diagnostic and treatment pathway for sleep‐disordered breathing. ASV, adaptive servo ventilation (*contraindicated in left ventricular systolic failure); CPAP, continuous positive airway pressure; CSA, central sleep apnoea; MAD, mandibular advancement device; NIV, non‐invasive ventilation; OSA, obstructive sleep apnoea; O2, oxygen; PSG, polysomnography; RPG, respiratory polygraphy; SDB, sleep‐disordered breathing; Sx, symptoms; −ve, negative result.

Figure 10.5 Cheyne–Stokes Breathing central sleep apnoea. Note: Crescendo–decrescendo ventilation alternating with apnoeas. Airflow cessation (PFLOW and Thermistor) is associated with absent chest and abdominal deflection, indicating loss of central respiratory drive.

Chapter 11

Figure 11.1 A normal actogram collecting at 0.5‐minute epochs from the Actiwatch (Camntech, UK) plotted over a 48‐hour timescale to show a regular day–night pattern in a 61‐year‐old female. Arrows denote periods of intense exercise (horse riding) which occurred regularly.

Figure 11.2 An actogram in a patient with a 3‐year history of Parkinson’s disease who was still working and driving with few subjective sleep complaints. Sleep diaries were completed showing consolidated blocks of sleep during the night only.

Chapter 12

Figure 12.1 Flow chart to illustrate diagnostic process. Note that the diagnosis may be reached at any step along the process; however, further investigation is indicated if diagnostic uncertainty remains. NFLE, nocturnal frontal lobe epilepsy.

Figure 12.2 Diagnostic algorithm for distinguishing NFLE/SHE from parasomnias based on video recording only.

Chapter 13

Figure 13.1 This 90‐second epoch of a nocturnal polysomnography of a patient with periodic limb movement disorder contains seven periodic leg movements during sleep. The overall PLMs index was 48/h. The PLMs (in this epoch only present in the right leg) occur every 10–15 seconds during sleep stage 2. Each leg movement is associated with an EEG arousal.

Figure 13.2 Flowchart outlining a general strategy for the initation of pharmacological therapy for RLS, and management of augmentation based on clinical experience.

Chapter 16

Figure 16.1 Flow chart for the diagnosis and management of excessive daytime sleepiness (EDS) in MD1. BiPAP, bi‐level positive airway pressure; CPAP, continuous positive airway pressure; PSG, polysomnography.

Chapter 17

Figure 17.1 Abnormal overnight pulse oximetry tracing from a patient with an underlying neuromuscular disease. Note the low baseline arterial oxygen saturation (SpO2) level consistently below 90% with superimposed cyclical worsening, suggesting sleep hypoxaemia with probable rapid eye movement (REM)‐related worsening or significant REM‐predominant obstructive sleep apnoea. Full night in‐lab polysomnography is necessary to make this distinction. A similar pattern may be seen in patients with pulmonary disorders.

Figure 17.2 A 90‐second epoch of rapid eye movement (REM) sleep from the overnight polysomnogram of an 18‐year‐old woman with limb girdle muscular dystrophy, complaining of orthopnoea, insomnia, frequent awakenings, excessive daytime sleepiness and cognitive concerns. The recording showed mild obstructive sleep apnoea, with an Apnoea–Hypopnoea Index of 10.3/hour, and an arterial oxygen saturation (SaO2) nadir of 93%. Note paradoxical breathing (upper box) in REM sleep, with alternating movements of the chest and abdominal effort belts, accompanied by a SaO2 desaturation of 3% (lower box).

Chapter 18

Figure 18.1 Algorithm for sleep‐related headache.

Chapter 19

Figure 19.1 A 20‐second EEG epoch, showing the onset of a nocturnal frontal lobe epilepsy (NFLE) seizure.

Chapter 20

Figure 20.1 Frequency of traumatic brain injury‐related sleep–wake disturbances in the first prospective study in 65 consecutive traumatic brain injury patients. Sleep–wake disturbances were assessed and characterised by interviews, questionnaires, sleep laboratory examinations including polysomnography, Multiple Sleep Latency Test and actigraphy.

Chapter 21

Figure 21.1 Effect of CPAP treatment on cardiovascular risk. The figure shows the incidence risk for the primary composite endpoints in three randomised controlled trials [74–76] in the CPAP compared with the control group (hazard ratio or incidence density ratio, 95% confidence interval) in the intention‐to‐treat analysis and in the adherence analysis (patients with CPAP adherence ≥4 hours/day). *In the McEvoy et al. [74] study, the significant cardiovascular improvement in patients who used CPAP ≥ 4 hours/day was only achieved in the risk of a cerebrovascular event, but not in the primary composite outcome.

Chapter 22

Figure 22.1 A practical stepwise approach to assess sleep disturbances and fatigue in MS.

Chapter 23

Figure 23.1 Coronal brain MRI showing amygdalar and hypothalamic high signal (see arrows to the hypothalamus) in a FLAIR sequence in a patient with anti‐Ma2 encephalitis and testicular germinoma who presented with hypersomnia.

Guide

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Sleep Disorders in Neurology

A Practical Approach

Edited by Sebastiaan Overeem and Paul Reading

Second Edition

This second edition first published 2018 © 2018 by John Wiley & Sons Ltd

Edition History [John Wiley and Sons 1e, 2010]

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Library of Congress Cataloging‐in‐Publication Data

Names: Overeem, Sebastiaan, editor. | Reading, Paul, editor.Title: Sleep disorders in neurology : a practical approach / edited by Sebastiaan Overeem, Paul Reading.Other titles: Sleep disorders in neurology (Overeem)Description: Second edition. | Hoboken, NJ : Wiley, 2017. | Includes bibliographical references and index. | Identifiers: LCCN 2018007682 (print) | LCCN 2018008043 (ebook) | ISBN 9781118777244 (pdf) | ISBN 9781118777220 (epub) | ISBN 9781118777268 (cloth)Subjects: | MESH: Sleep Wake Disorders–complications | Nervous System Diseases–complicationsClassification: LCC RC547 (ebook) | LCC RC547 (print) | NLM WL 108 | DDC 616.8/498–dc23LC record available at https://lccn.loc.gov/2018007682

Cover Design: WileyCover Image: © Marjot/iStock

List of Contributors

Kirstie N. AndersonRegional Sleep ServiceNewcastle upon Tyne Hospital NHS Foundation TrustNewcastle upon TyneUK

Isabelle ArnulfSleep Disorders UnitPitié‐Salpêtrière Hospital (APHP), Sorbonne UniversityParisFrance

Claudio L. BassettiDepartment of NeurologyBern University HospitalBernSwitzerland

Christian R. BaumannDepartment of NeurologyUniversity Hospital ZurichZurichSwitzerland

Sushanth BhatJFK Neuroscience InstituteHackensack Meridian Health‐JFK Medical CenterEdisonUSA

Valérie Cochen De CockDepartment of Neurology and Sleep DisordersClinique Beau SoleilMontpellierFrance

Chris DerryDepartment of Clinical NeurosciencesWestern General HospitalEdinburghUK

J. Gert van DijkDepartment of Neurology and Clinical NeurophysiologyLeiden University Medical CentreLeidenThe Netherlands

Jeroen J.J. van EijkDepartment of NeurologyJeroen Bosch HospitalDen BoschThe Netherlands

Luigi Ferini‐StrambiSleep Disorders CenterUniversity Vita‐Salute San RaffaeleMilanItaly

Joop van GervenCentre for Human Drug ResearchLeidenThe Netherlands

Francesc GrausNeurology ServiceHospital Clínic de BarcelonaBarcelonaSpainandInstitut d’Investigació Biomèdiques August Pi i Sunyer (IDIBAPS)BarcelonaSpain

Dirk M. HermannDepartment of NeurologyUniversity Hospital EssenEssenGermany

Alex IranzoNeurology ServiceHospital Clínic de BarcelonaBarcelonaSpainandInstitut d’Investigació Biomèdiques August Pi i Sunyer (IDIBAPS)BarcelonaSpainandCentro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)BarcelonaSpain

Brigit A. de JongDepartment of NeurologyVU University Medical CenterAmsterdamThe Netherlands

Gert Jan LammersDepartment of Neurology and Clinical NeurophysiologyLeiden University Medical CentreLeidenThe NetherlandsandSleep Wake Centre SEIN HeemstedeHeemstedeThe Netherlands

José Enrique Martínez‐RodríguezNeurology ServiceHospital del MarIMASIMIMBarcelonaSpain

Geert MayerSleep Disorders UnitHephata KlinikSchwalmstadt‐TreysaGermany

Christine NorraLWL Hospital Paderborn and Department of Psychiatry, Psychotherapy and Preventive MedicineRuhr University BochumBochumGermany

Sebastiaan OvereemCentre for Sleep Medicine ‘Kempenhaeghe'HeezeThe NetherlandsandEindhoven University of TechnologyEindhovenThe Netherlands

Dirk PevernagieCentre for Sleep Medicine ‘Kempenhaeghe'HeezeThe Netherlands

Angelique PijpersCentre for Sleep Medicine ‘Kempenhaeghe'HeezeThe Netherlands

J. Steven PocetaScripps Clinic Sleep CenterDivision of NeurologyScripps ClinicLa JollaUSA

Timothy G. QuinnellRespiratory Support and Sleep CentreRoyal Papworth HospitalCambridgeshireUK

Jeanetta C. RainsCenter for Sleep Evaluation at Elliot HospitalManchesterUSA

Paul ReadingDepartment of NeurologyJames Cook University HospitalMiddlesbroughUK

Gé S.F. RuigtClinical Consultancy for Neuroscience Drug DevelopmentOssThe Netherlands

Mojca van SchieDepartment of Neurology and Clinical NeurophysiologyLeiden University Medical CentreLeidenThe Netherlands

Markus H. SchmidtDepartment of NeurologyBern University HospitalBernSwitzerland

Pieter Jan SimonsCentre for Sleep Medicine ‘Kempenhaeghe'HeezeThe Netherlands

Bart Willem SmitsDepartment of NeurologyMaasstadziekenhuisRotterdamThe Netherlands

Karel ŠonkaDepartment of Neurology1st Medical FacultyCharles University and General Teaching HospitalPragueCzech Republic

Thom P.J. TimmerhuisDepartment of NeurologyJeroen Bosch HospitalDen BoschThe Netherlands

Ingrid VerbeekCentre for Sleep Medicine ‘Kempenhaeghe'HeezeThe Netherlands

Johan VerbraeckenDepartment of Pulmonary Medicine and Multidisciplinary Sleep Disorders CentreAntwerp University Hospital and University of AntwerpAntwerpBelgium

Marie VidailhetMovement Disorders UnitPitié‐Salpêtrière Hospital (APHP), CRICM UMR 975, and Paris 6 UniversityParisFrance

Thomas C. WetterDepartment of Psychiatry and PsychotherapyUniversity of RegensburgRegensburgGermany

Sue J. WilsonPsychopharmacology UnitDorothy Hodgkin BuildingUniversity of BristolBristolUK

Preface

An increasingly held perception is that medical textbooks have become the extinct ‘dinosaurs’ of information transfer and education. Indeed, the global availability of knowledge and thirst for brand new data, the inevitable delays in producing written multi‐authored texts, the expense of books together with the demise of traditional libraries would all appear to support this contention. In a rapidly changing environment, therefore, books, like dinosaurs, need to evolve in parallel and certainly be clearer in their aims than previously. Edited by a sleep physician and a general neurologist with a subspecialist interest in sleep, this book was conceived as a counterpoint to the established large encyclopaedic reference volumes currently available. The intentions were to cover areas not always addressed by standard sleep medicine or, indeed, neurology textbooks, at least from a practical perspective. The book is specifically aimed at clinicians and health care professionals not specifically trained or experienced in sleep medicine who nevertheless need to manage neurologically damaged patients with increasingly recognised sleep–wake disturbances. As such, we envisage the book will serve as an easily digested and practical handy companion, rather than as an exhaustive and fully referenced factual tome.

Largely for historical reasons, most neurologists receive little formal training in academic and clinical aspects of sleep medicine. Most sleep units are run solely by physicians primarily interested in breathing‐related sleep disorders and patients under their care may have little access to neurological expertise. This may seem paradoxical given conditions such as narcolepsy that are clearly ‘neurological’ with recently defined specific neuropathology and neurochemistry. The lack of exposure to sleep medicine naturally tends to produce neurologists with an unconfident, at best, or nihilistic, at worst, approach to sleep‐related symptoms in the clinic. By necessity, the situation is changing, especially given the increasingly recognised relevance of poor sleep or impaired wakefulness to quality of life issues in chronic neurological patients. Furthermore, it is clear to most clinicians that deterioration in sleep often coincides with or even causes worsening control of many chronic neurological conditions such as epilepsy.

Most neurologists would not expect to be referred cases of primary insomnia or obvious obstructive sleep apnoea although may well encounter them incidentally. Despite their high prevalence, there is relatively little emphasis on these common sleep disorders in this book and the focus is on those specific symptoms commonly experienced by neurological patients, assuming they are asked about them.

When sleep ‘goes wrong’ it impacts highly on all aspects of a subject’s well‐being and often their carer’s. As a result, increasing attention to patient choice has appropriately led to a higher expectation that such symptoms should be taken seriously. However, many neurologists with traditional approaches might feel that sleep problems are not disabling enough to warrant detailed attention. We would counter‐argue that ‘sleep is for the brain’ and without enough of it, the brain suffers. It is perhaps worthwhile recalling somewhat distasteful experiments from the late nineteenth century demonstrating that puppies could survive longer without water than without sleep.

The reputation that neurology is a discipline in which successful therapeutic options play second fiddle to diagnostic acumen is only partly true. Perhaps counter‐intuitively, treating sleep symptoms in neurology is often particularly rewarding, patients and carers appreciating even partial improvements in controlling their sleep–wake cycle. A recurrent theme in the book is that drugs to improve sleep are often selected using ‘medicine‐based’ evidence and personal experience than the gold standard of evidence‐based medicine. Despite this, together with the relative limited armamentarium of drugs available to the sleep physician, we believe that the majority of patients can be helped with a flexible and pragmatic approach. When drugs are mentioned, their proposed use is often ‘off licence’ and any prescriber will need to take responsibility for monitoring and progress. Similarly, doses of drugs are often approximate recommendations and it is not intended to provide strict or didactic guidelines. In many of the sleep‐disordered populations covered in the book, it is appropriate to suggest long‐term therapy on the assumption spontaneous improvement is unlikely. This often needs to be emphasised to primary care physicians who are more accustomed to providing short‐term prescriptions for sleep‐related problems.

The point or threshold at which a general neurologist should engage the help of a sleep specialist clearly depends on a number of factors. However, an exchange of views and expertise in a multidisciplinary setting, if possible at an early stage, would seem to be the best approach if facilities allow. We would encourage neurologists to forge stronger links with physicians more dedicated to sleep medicine in the firm belief any ‘cross fertilisation’ will benefit both sides.

By necessity, there is some overlap in the topics covered by some of the chapters. However, given the personal and practical approach we have espoused throughout the book, we hope different perspectives will improve rather than hinder understanding and effective symptom management in sleep‐disordered neurological patients.

In the Second Edition

The second edition of our handbook incorporates the changes outlined in the third International Classification of Sleep Disorders (ICSD‐3), published in 2014. The organisation of the book has also changed such that three parts now cover ‘General Sleep Medicine’; ‘Primary Sleep Disorders’; and ‘Sleep in Neurological Disorders’. It is hoped that the book will be a useful tool for those planning to gain a formal ‘somnologist’ qualification, given the increasing availability of a certification process in Europe, for example. Indeed, one encouraging development in many countries is the realisation that sleep medicine should be recognised as an important subspeciality with a formalised curriculum and specific assessment process. Inevitably, this will encourage and incentivise those fascinated by sleep and facilitate career pathways.

Eindhoven, The NetherlandsSebastiaan Overeem

and Middlesborough, UK, January 2018Paul Reading

Part OneGeneral Sleep Medicine

1The Sleep History

Paul Reading1 and Sebastiaan Overeem2,3

1 Department of Neurology, James Cook University Hospital, Middlesbrough, UK

2 Centre for Sleep Medicine ‘Kempenhaeghe’, Heeze, The Netherlands

3 Eindhoven University of Technology, Eindhoven, The Netherlands

Introduction

It is a commonly held misperception that practitioners of sleep medicine are highly dependent on sophisticated investigative techniques to diagnose and treat sleep‐disordered patients. However, it is relatively rare for detailed tests to add indispensable diagnostic information, provided a detailed, credible and accurate 24‐hour sleep–wake history is available. In fact, there can be few areas of medicine where a good, directed history is of more diagnostic importance. In some situations, this can be extremely complex due to interacting social, environmental, medical and psychological factors. Furthermore, obtaining an accurate sleep history often requires collateral or corroborative information from bed partners or close relatives, especially in the assessment of parasomnias.

In sleep medicine, neurological patients can present particular diagnostic challenges. It can often be difficult to determine whether a given sleep–wake symptom arises from the underlying neurological disorder and perhaps its treatment or whether an additional primary sleep disorder is the main contributor. The problem is compounded by the relative lack of formal training in sleep medicine received by the majority of neurology trainees that often results in reduced confidence when faced with sleep‐related symptoms. However, it is difficult to underestimate the potential importance of disordered sleep in many chronic and diverse neurological conditions such as epilepsy, migraine, multiple sclerosis and parkinsonism.

The following framework is a personal view on how to approach sleep–wake complaints from a neurological perspective. Although the focus is on individual or particular symptoms, it should be realised that several conditions can produce a variety of symptoms across the full 24‐hour sleep–wake period. In Chapters 2 and 3, the various ways in which sleep and sleepiness can be recorded are discussed. Then, in Chapter 4, an ‘integrative’ approach to diagnosis is outlined, illustrated by case examples.

Excessive Daytime Sleepiness

Excessive daytime sleepiness (EDS) is an increasingly recognised symptom that is deemed worthy of assessment. It is relatively prevalent and disabling both in general and neurological populations [1]. Many excessively sleepy patients may present to the medical profession indirectly, most often due to adverse indirect effects on cognition, motivation or mood. Indeed, the inability to focus or maintain concentration is often the most disabling aspect of conditions causing EDS, described as ‘brain fog’ or even masquerading as dementia. A not uncommon question posed to general neurologists is whether a sleepy patient might have narcolepsy or a similar primary, presumed ‘central’ sleep disorder. Furthermore, ‘secondary’ or ‘symptomatic’ narcolepsy is evolving as a valid concept given recent major advances in unravelling the neurobiology of sleep regulation. In particular, a variety of pathologies predominantly affecting the hypothalamus can mimic elements of idiopathic (primary) narcolepsy [2].

It is widely perceived that EDS is a normal phenomenon associated with the ageing process. In fact, objective measures of sleepiness suggest that healthy elderly subjects are actually less prone to falling asleep when unoccupied during the day compared with their younger counterparts. Although afternoon planned naps are probably a normal phenomenon with many elderly people in all cultures, evidence for EDS beyond this level should be taken seriously in all age groups.

In the initial assessment of EDS, it is essential to gain an impression of the severity of symptoms and how they are impacting on an individual subject. It is also crucial to confirm that the complaint is that of true excessive somnolence rather than simple fatigue or lethargy. Although sleepiness questionnaires are widely used and can act as an effective screening tool in this respect (Chapter 4), they rarely help with actual diagnosis. Directly asking a subject about particularly unusual, unplanned or inappropriate sleep episodes can therefore provide valuable insight. Habitual mid‐afternoon or late evening naps when unoccupied could be considered normal phenomena whereas regularly dropping to sleep mid‐morning or in public places usually indicates a problem. A history of invariably napping as a car passenger for journeys of over an hour may suggest pathological levels of sleepiness as may a complete inability to watch any film all the way through. In narcolepsy, the subject may describe sleep onset even whilst engaged in physical activities such as writing or standing. Furthermore, in severe EDS, the subject may report awakening from naps unaware of any prior imperative to sleep. So‐called ‘sleep attacks’ are recognised in narcolepsy and have been widely reported in sleepy parkinsonian patients. Regarding the latter population, recent evidence suggests that they may be particularly poor at monitoring their levels of subjective sleepiness, making the history from relatives particularly important [3].

The commonest causes of mild and severe EDS are probably insufficient sleep and poor quality overnight sleep, respectively. A directed history, perhaps backed by a sleep diary, usually helps in diagnosing the former and can indicate causes of the latter. If a subject regularly and reliably reports at least seven or eight hours of continuous sleep, yet remains significantly somnolent during the day, it is most likely that there is a disturbance of sleep architecture and, usually, that insufficient deep or restorative sleep is being obtained. An overabundance of light (stage N2) sleep compared with deep non‐rapid eye movement (REM) sleep (stage N3) is frequently seen in sleep‐related breathing disorders and periodic limb movement disorder. These diagnoses can easily be missed from the history if the subject is not a typical phenotype for the former or if they sleep alone. However, leading questions such as ‘do you invariably awake with a dry mouth?’ or ‘are the bed clothes usually disrupted on waking?’ can provide diagnostic pointers. Morning headaches or general sensations of ‘heaviness’ are traditionally associated with obstructive sleep apnoea although are equally common in a variety of sleep disorders.

A drug history including alcohol habit is also clearly relevant in assessing EDS as numerous agents given before bed may appear to induce drowsiness and aid sleep onset but actually worsen nocturnal sleep quality overall. Tricyclic preparations and benzodiazepines are frequently associated with unrefreshing sleep yet are frequently given primarily as hypnotic agents. It is worth noting that most antidepressants will potentially worsen restless legs syndrome or periodic limb movement disorder (Chapter 13).

Less recognised causes of disturbed nocturnal sleep may be picked up by a focused history. Nocturnal pain, frequent nocturia, persistent wheeze and acid reflux are usually fairly obvious ‘toxins’ to sleep and are generally readily reported. However, more subtle phenomena such as teeth grinding (bruxism) may not be recognised by the subject and only suspected if direct questions are asked about teeth wear, temporomandibular joint dysfunction or jaw pain, especially on waking.

A number of primary neurological disorders, including narcolepsy, disrupt the continuity of nocturnal sleep, most likely as a result of pathology in various brain regions intimately involved in sleep–wake control. A new symptom of sleep fragmentation and daytime somnolence in a patient with inflammatory brain disease such as multiple sclerosis, for example, might sometimes suggest inflammatory pathology in the pontomedullary area [4] or around the hypothalamus [5]. Idiopathic Parkinson’s disease is strongly associated with EDS, especially in the advanced stages. Although there are many potential causes, including dopaminergic medication, primary Lewy body brainstem pathology itself is a likely substrate for most of the sleep–wake dysregulation, especially with regards to REM sleep [6]. If a neurological patient complains of significant EDS and no obvious cause such as Parkinson’s disease is determined after a detailed history and subsequent sleep investigations, magnetic resonance brain imaging can be justified to exclude unexpected inflammatory or even structural pathology. This may particularly apply to sleepy, overweight children, for example [7].

There are usually sufficient clues from a patient’s history to suggest a specific diagnosis of narcolepsy, the quintessential primary disorder of sleep–wake dysregulation (Chapter 8). Typically, narcolepsy causes symptoms from early adolescence and profound delays in receiving a diagnosis are still commonplace. A detailed history, therefore, exploring issues of excessive sleepiness around schooling can be illuminating. Apart from its severity, the nature of sleepiness is not particularly exceptional or unique in narcolepsy. However, even short naps, planned or unplanned, tend to be restorative, allowing a ‘refractory’ wakeful period of 3–4 hours. Given that REM sleep is particularly dysregulated in narcolepsy, it is also useful to enquire about the presence of dreams, dream‐like experiences or sleep paralysis during short naps. Even when alert, the majority of narcoleptics will be prone to automatic behaviours and reduced powers of concentration or vigilance, potentially reflecting brief ‘micro‐sleeps’. These can be explored from a full history. Losing objects around the house or placing inappropriate objects such as mobile phones in the fridge are particularly common examples of this phenomenon.

Cataplexy is present in two‐thirds of narcoleptics and is very rarely seen in other situations. It is therefore an extremely specific phenomenon and important to recognise with confidence. Full‐blown episodes of temporary paralysis triggered by positive emotions or their anticipation are generally easy to pick up from the history. Subtle or atypical variants may be missed, however, especially since ‘going weak at the knees’ with laughter or other strong emotions is probably a normal phenomenon. Typically, cataplexy occurs in a relaxed or intimate environment in the company of friends or family. It is usually manifested by descending paralysis in a rostro‐caudal direction over two or three seconds, preceded by head bobbing or facial twitching. Subjects often learn to anticipate the situations in which they are at risk of attacks and may even develop social phobias as a result. Common precipitants include positive emotions such as surprise at meeting an old acquaintance or watching comedy on television. Some report that the anticipation of a positive emotion, perhaps as a punchline is approaching, acts as the most potent stimulus. Negative emotions such as frustration, particularly that induced by children or pets, can also induce episodes in many. Partial attacks can be missed or hidden. Indeed, minor facial twitching, head bobbing, mild neck weakness or a stuttering dysarthria when telling a joke may reflect the only observable manifestations of cataplexy. On the other hand, cataplexy is a doubtful explanation if episodes are very sudden or prolonged. Similarly, if conscious levels are significantly impaired or if injuries frequently incurred during attacks, alternative diagnoses need consideration.

Nocturnal symptoms in narcolepsy are extremely varied but frequently significant. Often to the surprise of physicians inexperienced with narcolepsy, restless sleep with impaired sleep maintenance and even sleep onset insomnia is common, as are excessive limb movements during sleep. The latter may reflect simple restlessness or periodic limb movements. Many narcoleptics also exhibit dream enactment during REM sleep although it generally appears as a more benign phenomenon to that commonly seen in neurodegenerative disease [8]. In particular, the movements tend to be less explosive or violent in narcolepsy and there is not the striking male predominance as observed in Parkinson’s disease, for example.

Unpleasant dreams that are particularly vivid and difficult to distinguish from reality are commonplace in narcolepsy. Indeed, narcoleptic children often become fearful of sleep as a result, so‐called ‘clinophobia’. Frank hallucinatory experiences in a variety of modalities including tactile may not be mentioned spontaneously through fear of being labelled mentally ill. These experiences are commonest around the sleep–wake transition periods or in states of drowsiness. A common example is the unpleasant sensation of a stranger in the bedroom in the absence of a frank hallucinatory vision or auditory perception. A full history should therefore actively explore such dream‐like experiences in detail.

A less common sleep disorder, idiopathic hypersomnolence (IH), can often mimic narcolepsy although certain historical pointers may help with the differential diagnosis [9]. IH in its classical form is characterised by long yet unrefreshing overnight sleep with prolonged napping during the day and continuous perception of reduced alertness. Difficulty with morning waking or prolonged confusion on forced waking are typical symptoms as are frequent acts of automatic behaviour during the day. Important negative historical features might include the lack of prominent REM sleep‐related phenomena. Overnight sleep is also usually undisturbed by arousals or excessive movement. It is recognised that mood disorders may be particularly common in IH although it is likely they are simply a consequence of the sleep disorder [10].

Although not a symptom routinely presented to neurologists, difficulty with morning waking is not uncommon and can lead to significant problems either with education or maintaining employment. If the sleep history indicates that the most likely cause is an abnormally late time of nocturnal sleep onset, the possibility of delayed sleep phase syndrome should be considered. This primarily affects adolescents and is often assumed simply to reflect socio‐behavioural factors. However, although bad habits may worsen the situation, it is often a defined disorder of circadian timing such that subjects are ‘hard wired’ to sleep and rise later than average, acting as extreme ‘night owls’ [11]. The diagnosis, if suspected, can be deduced from the history and subsequently supported by investigations.

Insomnia

Chronic insomnia either at sleep onset or through the night is undoubtedly common and most often reflects a combination of psychological and poorly defined constitutional factors. Although a patient’s history might indicate severe symptoms, it should be noted that a minority will have so‐called ‘paradoxical insomnia’ and will actually sleep fairly well when objectively investigated.

Many chronic insomniacs are able to identify a significant event or lifestyle change that seemed to trigger their sleep disturbance. Despite seemingly severe symptoms of poor nocturnal sleep and reported lethargy, most primary insomniacs are unable to nap during the day. The diagnosis of primary insomnia should therefore be questioned, and secondary causes sought in the presence of significant daytime somnolence. This is particularly relevant to neurological populations as insomnia symptoms are common and frequently adversely affect long‐term conditions such as epilepsy.

One of the commonest and most under‐recognised contributors to delayed sleep onset, sleep fragmentation and, indeed, daytime somnolence is restless legs syndrome (RLS) and associated periodic limb movement disorder (Chapter 13). RLS is defined solely from a positive history [12]. There should be frank restlessness, usually, but not always, in the lower limbs, most often associated with ill‐defined sensory symptoms that worsen in the late evening. Symptoms are triggered by rest or immobility and eased, at least temporarily, by movement or rubbing the affected limb or limbs. Associated involuntary jerks can be significant and intrude during wakefulness or light sleep, often adversely affecting sleep quality and causing daytime somnolence. The condition may not be suspected if the upper limbs are predominantly involved or if the symptoms are mistakenly attributed to arthritis or poor circulation, for example. In patients with underlying neuropathies, radiculopathies or demyelinating disease, RLS may be secondary to the primary diagnosis and should not be overlooked. Particularly in younger patients, a positive family history is common and should be actively sought from the history.

Discrete or identifiable brain pathology rarely leads to insomnia as an isolated phenomenon. However, it is relatively common both in neurodegenerative diseases and inflammatory disorders such as multiple sclerosis in the context of more obvious physical neurodisability [13]. Furthermore, insomnia can also be an apparent direct consequence of head injuries or strokes, particularly those producing subcortical pathology and potentially involving the paramedian thalamic region [14]. Insomnia and severely disturbed sleep are also increasingly recognised accompanying features of limbic encephalitis, a rare disorder in which fluctuating confusion, seizures and autonomic symptomology usually predominate [15]. Finally, delayed sleep phase syndrome sometimes presents as insomnia although, unlike the typical case of primary insomnia, by definition, there are also major problems in waking at a conventional hour.

A simple algorithm to assess insomnia presenting to a neurologist is shown in Figure 1.1.

Figure 1.1 Algorithm outlining a diagnostic approach to some of the common causes of primary and secondary insomnia that might present to neurologists.

Nocturnal Disturbances

Neurologists are frequently asked to assess patients with abnormal nocturnal behaviours or experiences, often to exclude epilepsy as a potential explanation. Distinguishing parasomnias from epileptic or psychiatric phenomena can clearly be difficult, especially given the practical issues of investigating nocturnal symptoms that are invariably intermittent (Chapter 12). However, a full history supported by spouses and family members together with a detailed background knowledge of parasomnias and their spectrum usually allow for a confident diagnosis.

Sleep–wake transition disorders are poorly studied but often alarming phenomena that may require reassurance if not treatment. They are relatively easy to recognise from the history. Most people are familiar with an occasional and slightly unpleasant sensation of sudden falling through space at the point of sleep onset. In sleep–wake transition disorders this phenomenon is amplified, more frequent and often accompanied by a variety of unusual and disturbing sensory or experiential symptoms such as loud auditory or intense visual stimuli. At the more severe end of the spectrum, the so‐called ‘exploding head syndrome’ has been described [16]. If frequent or recurrent, significant insomnia at sleep onset and through the night may result.

Parasomnias arising from non‐REM sleep are not rare in young adults and probably affect at least 1%. They usually reflect incomplete and abnormal arousals from deep non‐REM or slow wave sleep that can lead to a variety of complex and occasionally disturbing nocturnal behaviours. The events themselves usually have relatively little impact on daytime functioning or levels of sleepiness. For a confident diagnosis, it is important to ask about sleep‐related phenomena in early childhood as the majority will have a positive history for night terrors, confusional arousals, sleep walking, or all three. Given the likely genetic component to non‐REM parasomnias, a family history of nocturnal disturbances, including sleep talking, can also be insightful. In adults, a frequency of one or two events a month is typical, often with identifiable precipitants. These include sleep deprivation, alcohol intake before bed or sleeping in an unfamiliar or uncomfortable environment. Coinciding with the first period of deep non‐REM sleep, the nocturnal disturbance will generally occur within an hour or two of sleep onset and will rarely recur through the night. Subsequent recollection of the event by the subject is at best hazy although agitated events may produce vague memories of non‐specific threats or frightening situations. Detailed or bizarre dream narratives are rare. Events can be prolonged and the subject may appear superficially awake, responding in a limited way to questions and commands. Relatively complex motor tasks such as eating, performing housework and driving are certainly possible.

Distinguishing adult non‐REM parasomnias from nocturnal complex partial seizures can be difficult as both may produce complicated behaviours and confusion (Chapter 12). Epileptic episodes are often of frontal lobe origin and can occur several or many times a night from any sleep stage, except REM sleep. If detailed descriptions or, ideally, video clips of several events demonstrate strictly stereotyped episodes, especially with fixed or dystonic limb posturing, a diagnosis of epilepsy is likely. Alternatively, if episodes are long‐lasting with an indistinct termination or if they appear to wax and wane, a parasomnia is favoured. Strongly expressed emotions or leaving the bed are not particularly discriminatory features.

In a neurological setting, it is commoner to see parasomnias arising from REM sleep, particularly in the context of parkinsonian neurodegenerative disease. In particular, REM sleep behaviour disorder (RBD) typically affects men in late middle‐age, often many years in advance of any motor or, indeed, cognitive symptomology [17]. The nocturnal disturbances are usually of more concern to the bed partner who may incur injuries from violent dream enactment. The episodes themselves are generally more frequent and prolonged at the end of the night when REM sleep is more prevalent. Movements are often associated with vocalisation and tend to be defensive, brief and undirected, typically involving the upper limbs with eyes generally closed. The subject is usually fairly easy to arouse to full wakefulness and will often recall a vivid dream, perhaps involving previous acquaintances or occupations. In certain conditions such as multiple system atrophy and narcolepsy, RBD seems to affect females equally [18]. Moreover, in narcolepsy, the dreams and movements may be relatively banal and probably reflect differing underlying pathogenetic mechanisms to those seen in parkinsonism.

The causes of generally restless sleep can be difficult to diagnose from history alone even if detailed witnessed accounts and videos are available. Periodic limb movement disorder can exist in the absence of RLS and is relatively common. Persistent rocking or stereotyped rolling movements involving virtually any body part may reflect a so‐called rhythmic movement disorder. This often evolves from childhood ‘head banging’ at sleep onset although can occur in any sleep stage, even REM sleep, in adults [19]. As with many parasomnias, the bed partner is usually the main complainant.

Conclusions

As within many areas of neurology, a detailed and directed history is paramount when trying to diagnose sleep disorders. The need for a full 24‐hour sleep–wake history should be emphasised, corroborated where possible by observers or family members. At the very least, a good history usually provides a credible differential diagnosis which investigations may subsequently further refine. However, if significant diagnostic doubt remains after obtaining a full sleep history, it is relatively rare for sleep investigations to fully elucidate the problem. Furthermore, given the expense and patchy distribution of specialist sleep centres, the sleep history assumes particular diagnostic importance.

Disordered sleep is undoubtedly prevalent in neurological disease and may exacerbate underlying conditions such as migraine and epilepsy. Aside from their direct deleterious effects on daily and nightly functioning, there is therefore ample justification for taking sleep‐related symptoms seriously in a neurological setting.

Key Points

The patient history is the single most important diagnostic tool in neurological sleep medicine.

In neurological patients, it can sometimes be difficult to determine whether a sleep–wake symptom is due to an underlying neurological disorder, its treatment or a coexisting primary sleep disorder.

Excessive daytime sleepiness is not uncommon, and may easily be missed or mistaken for fatigue, cognitive impairment or mood disorder.

Additional symptoms not directly related to the sleep–wake cycle may be crucial for the diagnosis (e.g. cataplexy in the case of narcolepsy).

Sleep onset or sleep maintainance insomnia can reflect an idiopathic or primary phenomenon but is more often secondary to a variety of disorders, including other primary sleep disorders (e.g. RLS), psychiatric (e.g. depression) or neurological disease (e.g. multiple sclerosis, neurodegenerative diseases or stroke).

A knowledge of the typical pattern and spectrum of the various parasomnias normally allows a confident history from history alone and helps exclude epilepsy as a diagnosis.

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