Excessive Fragmentary Myoclonus Research Articles

Effect of positive airway pressure treatment on excessive fragmentary myoclonus in 100 sleep-related breathing disorder patients

Study objectivesExcessive fragmentary myoclonus (EFM) is a frequent finding in patients undergoing video-polysomnography (VPSG). We aimed to evaluate the potential effect of sleep-related breathing disorder's treatment with positive airway pressure (PAP) therapy on EFM. MethodsOne hundred consecutive patients with EFM and sleep-related breathing disorder subsequently treated with PAP at the sleep lab of the Medical University of Innsbruck, Department of Neurology, Austria, were included. Each patient underwent two nights of VPSG: the first night without and the second night with PAP therapy. Fragmentary myoclonus was automatically scored with validated software, and fragmentary myoclonus index (FMI) and minutes of non-rapid eye movement (NREM) sleep with EFM (minNREM+EFM) were calculated. ResultsUnder PAP therapy there was a significant decrease in the minNREM+EFM — 60.5 (9.5–161.8) at baseline vs. 37.5 (6.3–168.8) minutes under PAP, p = 0.025. No significant differences were observed for FMI between the two nights. Sleep variables, sleep diagnoses, comorbidities, and medication did not influence FMI or the minNREM+EFM. ConclusionsThe initiation of PAP treatment led to a significant reduction of minNREM+EFM, but not of FMI. The results suggest that PAP therapy might influence the distribution of FM potentials.

Neurological, psychiatric, and sleep investigations after treatment of anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis in Spain: a prospective cohort study

Anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis is an autoimmune disorder that can be treated with immunotherapy, but the symptoms that remain after treatment have not been well described. We aimed to characterise the clinical features of patients with anti-LGI1 encephalitis for 1 year starting within the first year after initial immunotherapy. For this prospective cohort study, we recruited patients with anti-LGI1 encephalitis as soon as possible after they had received conventional immunotherapy for initial symptoms; patients were recruited from 21 hospitals in Spain. Patients were excluded if they had an interval of more than 1 year since initial immunotherapy, had pre-existing neurodegenerative or psychiatric disorders, or were unable to travel to Hospital Clínic de Barcelona (Barcelona, Spain). Patients visited Hospital Clínic de Barcelona on three occasions-the first at study entry (visit 1), the second 6 months later (visit 2), and the third 12 months after the initial visit (visit 3). They underwent neuropsychiatric and videopolysomnography assessments at each visit. Healthy participants who were matched for age and sex and recruited from Hospital Clínic de Barcelona underwent the same investigations at study entry and at 12 months. Cross-sectional comparisons of clinical features between groups were done with conditional logistic regression, and binary logistic regression was used to assess associations between cognitive outcomes at 12 months and clinical features before initial immunotherapy and at study entry. Between May 1, 2019, and Sept 30, 2022, 42 participants agreed to be included in this study. 24 (57%) participants had anti-LGI1 encephalitis (mean age 63 years [SD 12]; 13 [54%] were female and 11 [46%] were male) and 18 (43%) were healthy individuals (mean age 62 years [10]; 11 [61%] were female and seven [39%] were male). At visit 1 (median 88 days [IQR 67-155] from initiation of immunotherapy), all 24 patients had one or more symptoms; 20 (83%) patients had cognitive deficits, 20 (83%) had psychiatric symptoms, 14 (58%) had insomnia, 12 (50%) had rapid eye movement (REM)-sleep behaviour disorder, nine (38%) had faciobrachial dystonic seizures, and seven (29%) had focal onset seizures. Faciobrachial dystonic seizures were unnoticed in four (17%) of 24 patients and focal onset seizures were unnoticed in five (21%) patients. At visit 1, videopolysomnography showed that 19 (79%) patients, but no healthy participants, had disrupted sleep structure (p=0·013); 15 (63%) patients and four (22%) healthy participants had excessive fragmentary myoclonus (p=0·039), and nine (38%) patients, but no healthy participants, had myokymic discharges (p=0·0051). These clinical and videopolysomnographic features led to additional immunotherapy in 15 (63%) of 24 patients, which resulted in improvement of these features in all 15 individuals. However, at visit 3, 13 (65%) of 20 patients continued to have cognitive deficits. Persistent cognitive deficits at visit 3 were associated with no use of rituximab before visit 1 (odds ratio [OR] 4·0, 95% CI 1·5-10·7; p=0·0015), REM sleep without atonia at visit 1 (2·2, 1·2-4·2; p=0·043), and presence of LGI1 antibodies in serum at visit 1 (11·0, 1·1-106·4; p=0·038). Unsuspected but ongoing clinical and videopolysomnography alterations are common in patients with anti-LGI1 encephalitis during the first year or more after initial immunotherapy. Recognising these alterations is important as they are treatable, can be used as outcome measures in clinical trials, and might influence cognitive outcome. Fundació La Caixa.

A 24% prevalence of excessive fragmentary myoclonus in 500 consecutive sleep laboratory patients.

Excessive fragmentary myoclonus (EFM) is a frequent finding during routine video-polysomnography (VPSG). We aimed to automatically measure the prevalence of EFM according to current American Academy of Sleep Medicine (AASM) criteria, and the fragmentary myoclonus index (FMI) in sleep stage N1, N2, N3, rapid eye movement (REM) sleep and wake in a large patient population. A total of 500 VPSG recordings of patients admitted to the Sleep Laboratory, Department of Neurology, Medical University of Innsbruck, Austria, between May 1, 2022 and February 28, 2023, were included. EFM according to AASM criteria and FMI were computed by applying a previously validated algorithm. EFM was automatically detected in 121 of the 500 Sleep Laboratory patients (24.2%, 95% confidence interval 20.1%-28.9%). FMI increased with age, male gender, apnea-hypopnea-index (AHI), oxygen desaturation index (ODI), and periodic leg movements of sleep (PLMS) index. FMI was highest in REM sleep behaviour disorder (RBD), followed by neurodegenerative and internal medicine diseases, but the increase in the FMI was not explained by the disease itself but rather by the age and sex of the patients. Almost a quarter of our patient population had EFM. However, the prevalence of EFM does not allow the drawing of any conclusions about the pathophysiology of EFM or even the determination of a pathological FMI cut-off value. Associations of the FMI with age, sex, AHI, ODI and PLMS are in line with previous studies, but the FMI needs to be evaluated in different disease entities to learn more about its pathophysiology.

A reliable automatic algorithm to score fragmentary myoclonus.

Excessive fragmentary myoclonus (EFM) is an incidental polysomnographic finding requiring documentation of ≥20 minutes of NREM sleep with ≥5 fragmentary myoclonus (FM) potentials per minute. Manual FM scoring is time-consuming and prone to inter-rater variability. This work aimed to validate an automatic algorithm to score FM in whole-night recordings. One expert scorer manually scored FM in the anterior tibialis muscles in 10 polysomnographies of as many subjects. The algorithm consisted of two steps. First, parameters of the automatic leg movement identification algorithm of the BrainRT software (OSG, Belgium) were modified to identify FM-like activity. Second, a post-processing algorithm was implemented to remove FM activity not meeting sufficient amplitude criteria. The parameter choice and the post-processing were optimised with leave-one-out cross-validation. Agreement with the human scorer was measured with Cohen's kappa (k) and correlation between manual and automatic FM indices in different sleep stages was evaluated. Agreement in identifying patients with EFM was computed. The algorithm showed substantial agreement (average k > 0.62) for all sleep stages, except for W, where a moderate agreement was observed (average k = 0.58). Nonetheless, the agreement between human scorer and the algorithm was similar to previously reported values of inter-rater variability for FM scoring. Correlation coefficients were over 0.96 for all sleep stages. Furthermore, the presence/absence of EFM was correctly identified in 80% of the subjects. In conclusion, this work presents a reliable algorithm for automatic scoring of FM and EFM. Future studies will apply it to objectively and consistently evaluate FM indices and the presence of EFM in large populations.

Incidental Detection of Anti-IgLON5: A Diagnostic and Therapeutic Dilemma (P5-5.021)

<h3>Objective:</h3> To report a patient in whom anti-IgLON5 was incidentally detected as part of work-up for possible autoimmune-associated epilepsy. <h3>Background:</h3> Anti-IgLON5 disease has recently been characterized. Core manifestations include sleep disturbances, bulbar dysfunction, gait instability, chorea and cognitive decline, while seizures are not typical. Response to immunotherapy is usually suboptimal and prognosis is frequently poor, although early treatment could improve outcomes. <h3>Design/Methods:</h3> Case report. <h3>Results:</h3> A 49-year-old woman had an 18-year-history of temporal lobe epilepsy that developed after cervical cancer. Brain MRI was unremarkable but EEG showed right temporal epileptiform discharges and PET showed right temporal hypometabolism, compatible with right temporal seizure origin. Due to seizure refractoriness and history of cancer, comprehensive neural antibody testing for possible autoimmune-associated epilepsy was pursued and revealed anti-IgLON5 in serum and cerebrospinal fluid. On directed history, the patient reported snoring and insomnia that had developed two years prior, which were symptoms she had not initially volunteered because she felt they were mild and stable. Neurologic examination was unremarkable. The patient received a six-week trial of corticosteroids, without improvement in seizure frequency or sleep disturbances. Polysomnography revealed minimal sleep disordered breathing, mild arousals from slow wave sleep, unusually prominent beta activity in REM sleep, and excessive fragmentary myoclonus, which may represent early anti-IgLON5 disease. <h3>Conclusions:</h3> Diagnostically, we hypothesize that anti-IgLON5 is unrelated to chronic temporal lobe epilepsy in our patient, which we suspect is idiopathic. However, this antibody may explain sleep findings, and the mildness of her symptoms referable to anti-IgLON5 disease creates a unique therapeutic dilemma. In discussion with the patient, we have opted to monitor clinically and with polysomnography, and to consider institution of further immunotherapy if there is demonstrable disease progression. Future study into the natural history of anti-IgLON5 disease is needed to determine the optimal management of patients with mild symptoms. <b>Disclosure:</b> Dr. Alkabie has nothing to disclose. The institution of Dr. Murray has received research support from Wake Up Narcolepsy. Dr. Murray has received publishing royalties from a publication relating to health care. Dr. Budhram has nothing to disclose.

A prospective case-control study of excessive fragmentary myoclonus in the upper and lower extremities: Clinical characteristics and electrophysiological correlates

BackgroundExcessive fragmentary myoclonus (EFM) is an incidental finding in video-polysomnography (VPSG) and listed among “Sleep Related Movement Disorders – Isolated symptoms and normal variants” in the ICSD-3. We aimed to prospectively evaluate EFM in the upper and lower extremities in a large sleep laboratory cohort and to investigate clinical characteristics and peripheral nerve pathology in patients with and without EFM. MethodsTwo-hundred consecutive sleep laboratory patients with EFM according to ICSD-3 criteria were included and matched to 100 patients without EFM for age, sex and presence or absence of sleep-related breathing disorder. Patients additionally underwent peripheral neurophysiological work-up. ResultsIn 31/200 (15.5%) patients EFM was present not only in the lower extremities, but also in the upper extremities. Patients with EFM had less REM sleep (%/SPT; median (IQR); 13.8 (9.1–18.2) vs. 17.1 (10.1–20.5); p = 0.008) and the PLMS-Index was higher in patients with EFM than in those without (16.2 vs. 8.8/h; p = 0.009). Polyneuropathy (PNP) and nerve root lesions L5 and S1 were more frequent in patients with than in those without EFM (31.5% vs. 21% and 5% vs. 0%; p = 0.003). ConclusionsIn this large cohort we systematically investigated upper and lower extremities with surface electromyography during sleep and show that EFM is much more frequent in the lower extremities than in the upper extremities and corroborate the association of EFM with peripheral nerve pathology and PLMS.

The Parasomnias and Sleep Related Movement Disorders—A Look Back at Six Decades of Scientific Studies

The objective of this article is to provide a comprehensive personal survey of all the major parasomnias with coverage of their clinical presentation, investigation, physiopathogenesis and treatment. These include the four major members of the slow-wave sleep arousal parasomnias which are enuresis nocturna (bedwetting), somnambulism (sleepwalking), sleep terrors (pavor nocturnus in children, incubus attacks in adults) and confusional arousals (sleep drunkenness). Other parasomnias covered are sleep-related aggression, hypnagogic and hypnopompic terrifying hallucinations, REM sleep terrifying dreams, nocturnal anxiety attacks, sleep paralysis, sleep talking (somniloquy), sexsomnia, REM sleep behavior disorder (RBD), nocturnal paroxysmal dystonia, sleep starts (hypnic jerks), jactatio capitis nocturna (head and total body rocking), periodic limb movement disorder (PLMs), hypnagogic foot tremor, restless leg syndrome (Ekbom syndrome), exploding head syndrome, excessive fragmentary myoclonus, nocturnal cramps, and sleep-related epileptic seizures. There is interest in the possibility of relationships between sleep/wake states and creativity.

Fragmentary myoclonus in idiopathic rapid eye movement sleep behaviour disorder.

Fragmentary myoclonus is a result of muscle activity consisting of brief potentials in surface electromyography during polysomnography. Excessive fragmentary myoclonus is defined by increased intensity of the potentials. A few studies report excessive fragmentary myoclonus occurrence in neurodegenerative diseases. Because idiopathic rapid eye movement sleep behaviour disorder is considered as an early stage of neurodegeneration with involvement of the brainstem, we charted the prevalence and quantified the intensity of excessive fragmentary myoclonus in idiopathic rapid eye movement sleep behaviour disorder. Twenty-nine patients (one woman, 28 men, mean age 68 years, SD 6.2) and 29 controls (two women, 27 men, mean age 65.6 years, SD 8.6) underwent polysomnography. Fragmentary myoclonus potentials were identified and counted according to internationally used criteria. Fragmentary myoclonus intensity was quantified by the fragmentary myoclonus index. Excessive fragmentary myoclonus was diagnosed in 75.9% (22 subjects) in idiopathic rapid eye movement sleep behaviour disorder, while in 34.5% (10 subjects) among the controls (p = 0.003). Quantitative analysis showed a wide-range fragmentary myoclonus index in idiopathic rapid eye movement sleep behaviour disorder (4.0-632.4; median 60.7) and in the controls (0.8-938.1; median 34.3). The overall difference in fragmentary myoclonus index was not significant between the groups; however, patients with idiopathic rapid eye movement sleep behaviour disorder showed trends for higher fragmentary myoclonus index scores in wakefulness (p = 0.027), N1 (p = 0.032), N3 (p = 0.046) and R (p = 0.007). Fragmentary myoclonus index does not correlate with age, idiopathic rapid eye movement sleep behaviour disorder duration or R stage atonia deficiency. The prevalence of excessive fragmentary myoclonus is higher in idiopathic rapid eye movement sleep behaviour disorder compared with the controls, so fragmentary myoclonus should be taken into account in future research of rapid eye movement sleep behaviour disorder and motor control in sleep.

0682 A Novel, Highly Efficient REM Sleep without Atonia Visual Analysis Method for REM Sleep Behavior Disorder Diagnosis

Polysomnographic REM sleep without atonia (RSWA) is requisite for REM sleep behavior disorder (RBD) diagnosis, yet traditional scoring criteria for phasic muscle bursts (requiring minimum duration of 100ms) are tedious and labor intensive, and overlap with state-independent excessive fragmentary myoclonus. Furthermore, traditional quantitative RSWA metrics have created confusion and further limited adaption of RSWA quantification by sleep clinicians. We aimed to simplify phasic RSWA scoring criteria and derived RSWA metrics to expedite RSWA analysis while maintaining high diagnostic precision. Fifteen iRBD patients and 30 OSA controls who have been previously reported underwent manual RSWA analysis utilizing a 1 second minimum phasic muscle duration cutoff (maximum 14.9 seconds). RSWA was analyzed in the submentalis (SM) and anterior tibialis (AT) muscles. The total duration of REM sleep with phasic muscle activity was divided by total non-artifact REM time, yielding a “density of muscle activity” during REM sleep. Parametric mean comparison and receiver operating characteristic (ROC) curves were used to determine the best diagnostic cutoff thresholds for RBD and compared with previously published cutoffs from this cohort. Mean RSWA densities were significantly higher in RBD patients vs. OSA controls, for both SM (11% vs. 0.4%, p<0.01) and AT (10% vs. 1.3%, p<0.01), with best diagnostic cut-offs for SM of 4.0% (AUC = 0.92) and AT of 4.3% (AUC = 0.94), which were highly similar to previously determined diagnostic discrimination using shorter phasic burst duration scoring criteria. Increasing minimum phasic duration criteria to 1 second, with calculation of a unitary RSWA metric greatly simplifies and expedites manual RSWA analysis without sacrificing diagnostic sensitivity and specificity, yielding an approach to RSWA analysis that is both more intuitive and easily employed in busy clinical sleep laboratory settings. Support (If Any):

Excessive Fragmentary Myoclonus: What Do We Know?

Excessive fragmentary myoclonus (EFM) is a polysomnographic finding registered by the surface electromyography (EMG) and characterized as a result of the muscle activity consisting of sudden, isolated, arrhythmic, asynchronous and asymmetric brief twitches. The EMG potentials are defined by the exact criteria in The International Classification of the Sleep Disorders, 3rd edition and they appear with high intensity in all sleep stages. Clinical significance of EFM is unclear. It was observed in combination with other diseases and features such as obstructive and central sleep apnea, narcolepsy, periodic limb movements, insomnia, neurodegenerative disorders and peripheral nerve dysfunction. Relation to such wide range of diseases supports the opinion that EFM is nor a specific sleep disorder nor a specific polysomnographic sign. The option that EFM is a normal variant has also not been ruled out so far.

Quantifying Leg Movement Activity During Sleep.

Currently, 2 sets of similar rules for recording and scoring leg movement (LM) exist, including periodic LM during sleep (PLMS) and periodic LM during wakefulness. The former were published in 2006 by a task force of the International Restless Legs Syndrome Study Group, and the second in 2007 by the American Academy of Sleep Medicine. This article reviews the basic recording methods, scoring rules, and computer-based programs for PLMS. Less frequent LM activities, such as alternating leg muscle activation, hypnagogic foot tremor, high-frequency LMs, and excessive fragmentary myoclonus are briefly described.

Peripheral nerve function in patients with excessive fragmentary myoclonus during sleep

ObjectivesExcessive fragmentary myoclonus is a frequent incidental finding in patients undergoing polysomnography for other reasons. The aim of this study was to evaluate whether electrophysiological examination in patients with excessive fragmentary myoclonus during sleep according to American Academy of Sleep Medicine (AASM) criteria shows findings of peripheral nerve dysfunction. MethodsNinety-eight of 100 patients with excessive fragmentary myoclonus detected as an incidental finding during routine polysomnography underwent electrophysiological workup. Motor nerve conduction studies of the right peroneal and tibial nerves, F-wave recordings of the tibial nerve, antidromic sensory nerve conduction studies of the left sural nerve and needle electromyography of the right tibialis anterior muscle were performed and classified as normal, peripheral neuropathy, lumbar 5 (L5) nerve root lesion, or benign fasciculations. ResultsFifty percent (49 out of 98) presented with electrophysiological abnormalities, most frequently polyneuropathy (32 out of 49, 65.3%), followed by L5 nerve root lesions (13 out of 49, 26.5%) and benign fasciculations (4 out of 49, 8.2%). Patients with electrophysiological abnormalities were older than those without. ConclusionsThe high prevalence of abnormal neurophysiological findings in patients with excessive fragmentary myoclonus during polysomnography suggests that excessive fragmentary myoclonus during sleep according to AASM criteria is not primarily a sleep-related phenomenon, but only persists during sleep and points to peripheral nerve pathology at least in part of the cases. Patients with incidental EFM during polysomnography should undergo electrophysiological workup for peripheral nerve pathology.

NREM-related parasomnias in Machado-Joseph disease: clinical and polysomnographic evaluation.

Spinocerebellar ataxias (SCA) are autosomal dominant neurodegenerative disorders that affect the cerebellum and its connections, and have a marked clinical and genetic variability. Machado-Joseph disease (MJD) or spinocerebellar ataxia type 3 (SCA3)--MJD/SCA3--is the most common SCA worldwide. MJD/SCA3 is characterized classically by progressive ataxia and variable other motor and non-motor symptoms. Sleep disorders are common, and include rapid eye movement (REM) sleep behaviour disorder (RBD), restless legs syndrome (RLS), insomnia, excessive daytime sleepiness, excessive fragmentary myoclonus and sleep apnea. This study aims to focus upon determining the presence or not of non-REM (NREM)-related parasomnias in MJD/SCA 3, using data from polysomnography (PSG) and clinical evaluation. Forty-seven patients with clinical and genetic diagnosis of MJD/SCA3 and 47 control subjects were evaluated clinically and by polysomnography. MJD/SCA3 patients had a higher frequency of arousals from slow wave sleep (P < 0.001), parasomnia complaints (confusional arousal/sleep terrors, P = 0.001; RBD, P < 0.001; and nightmares, P < 0.001), REM sleep without atonia (P < 0.001), periodic limb movements of sleep index (PLMSi) (P < 0.001), percentage of N3 sleep (P < 0.001) and percentage of N1 sleep (P < 0.001). These data show that NREM-related parasomnias must be included in the spectrum of sleep disorders in MJD/SCA3 patients.

Excessive Fragmentary Myoclonus: Case Report

Excessive Fragmentary Myoclonus: Case Report

Excessive fragmentary myoclonus in patients with Parkinson's disease: prevalence and clinico-polysomnographic profile.

Excessive fragmentary myoclonus (EFM) is characterized by subtle arrhythmic and excessive jerks that are usually asymmetric and asynchronous. EFM occurs in different areas of the body, mainly the face and distal parts of the arms and legs, and is detected by surface electromyography during sleep. The present study aimed to determine the prevalence of EFM in Parkinson's disease (PD) patients at a tertiary level outpatient clinic as well as to describe the clinical and polysomnographic profiles of these patients. A total of 62 consecutive PD patients were included in the study. Patients were evaluated using the Brazilian version of the PD Sleep Scale, Portuguese Language version of Epworth's Daytime Sleepiness Scale validated for Brazilian population, Brazilian Portuguese version of PD Quality of Life Scale, and Global Deterioration Scale. Evaluation of the sleep disorders was performed by clinical interview and polysomnography. EFM was found in 62.7% of PD patients. EFM was found to be associated with obstructive sleep apnea syndrome and advanced age. EFM occurs in a significantly high proportion of PD patients and is related to obstructive sleep apnea syndrome (OSAS) and advanced age, so EFM should be systematically investigated by polysomnography (PSG) in PD patients.

Motor Events during Healthy Sleep: A Quantitative Polysomnographic Study

Many sleep disorders are characterized by increased motor activity during sleep. In contrast, studies on motor activity during physiological sleep are largely lacking. We quantitatively investigated a large range of motor phenomena during polysomnography in physiological sleep. Prospective polysomnographic investigation. Academic referral sleep laboratory. One hundred healthy sleepers age 19-77 y were strictly selected from a representative population sample by a two-step screening procedure. N/A. Polysomnography according to American Academy of Sleep Medicine (AASM) standards was performed, and quantitative normative values were established for periodic limb movements in sleep (PLMS), high frequency leg movements (HFLM), fragmentary myoclonus (FM), neck myoclonus (NM), and rapid eye movement (REM)-related electromyographic (EMG) activity. Thirty-six subjects had a PLMS index > 5/h, 18 had a PLMS index > 15/h (90th percentile: 24.8/h). Thirty-three subjects had HFLM (90th percentile: four sequences/night). All subjects had FM (90th percentile 143.7/h sleep). Nine subjects fulfilled AASM criteria for excessive FM. Thirty-five subjects had NM (90th percentile: 8.8/h REM sleep). For REM sleep, different EMG activity measures for the mentalis and flexor digitorum superficialis muscles were calculated: the 90th percentile for phasic mentalis EMG activity for 30-sec epochs according to AASM recommendation was 15.6%, and for tonic mentalis EMG activity 2.6%. Twenty-five subjects exceeded the recently proposed phasic mentalis cutoff of 11%. None of the subjects exceeded the tonic mentalis cutoff of 9.6%. Quantification of motor phenomena is a basic prerequisite to develop normative values, and is a first step toward a more precise description of the various motor phenomena present during sleep. Because rates of motor events were unexpectedly high even in physiological sleep, the future use of normative values for both research and clinical routine is essential.

Excessive fragmentary myoclonus in Machado–Joseph disease

ObjectiveMachado–Joseph disease (MJD) is a neurodegenerative disease which usually presents several clinical findings including cerebellar ataxia and other extracerebellar features, such as Parkinsonism, dystonia, peripheral neuropathy, and lower motor neuron disease. Some data have demonstrated a high frequency of sleep disorders in these patients, including excessive daytime sleepiness (EDS), insomnia, obstructive sleep apnea (OSA), rapid eye movement (REM) sleep behavior disorder (RBD), and restless legs syndrome (RLS). Herein, we aimed to describe the high frequency of excessive fragmentary myoclonus (EFM) in MJD. Materials and methodsWe recruited 44 patients with MJD and 44 healthy controls. All participants underwent an all-night polysomnography (PSG). EFM was evaluated and defined in accordance to the criteria of the American Academy of Sleep Medicine. ResultsHalf of the MJD patients (n=22) had EFM diagnosed through PSG, though no healthy control participant presented this finding (P<.0001). In the MJD group, older participants and men had a higher frequency of EFM. There was no correlation between EFM and the following data: body mass index (BMI), apnea–hypopnea index (AHI), EDS, loss of atonia during REM sleep, periodic limb movements during sleep (PLMS), RLS, RBD, ataxia severity, the number of cytosine–adenine–guanine trinucleotide (CAG) repeats, disease duration, sleep efficiency, sleep fragmentation, and sleep stage percentages between patients with or without EFM. ConclusionEFM is highly prevalent in patients with MJD. Our study demonstrates that EFM must be included in the clinical spectrum of sleep disorders in MJD patients.

Assessment of fragmentary myoclonus in healthy sleepers

Introduction Fragmentary myoclonus (FM) is characterised by a multifocal synchronic and asymmetric distribution of EMG potentials with a duration of 75–150 msec and an amplitude exceeding 50 μV. The extreme form of FM is excessive fragmentary myoclonus (EFM). The presence of FM has been described in many sleep disorders, its clinical relevance, however, is still under debate. In the International Classification of Sleep Disorders-2 it is therefore listed in the category “Isolated Symptoms, apparently Normal Variants and Unresolved Issues”. The aim of this study was to assess FM in healthy sleepers. Materials and methods One-hundred healthy sleepers (60 f, 40 m) aged 19–77 years were selected from a representative Tyrolean population sample. A two-step screening process (telephone interview, personal investigation by a sleep-trained physician) was performed for exclusion of a relevant sleep, neurological, psychiatric or internal comorbidity as well as any use of a CNS active medication. All participants underwent one video-polysomnography. Analysis of FM was part of the comprehensive analysis of motor phenomena during sleep. It was quantitatively assessed according to Lins et al. EFM was diagnosed according to AASM 2007. Results Every study participant had FM. Median FM index in sleep was 25.3/h [range 3/h–1102/h]. The highest rates were seen in REM 38/h [0/h–1102/h] sleep followed by N1 34.4/h [3/h–1048/h] and N2 22.3/h [1.5/h–1032/h] sleep. The lowest values were found in N3 37.8/h [0/h–1200/h] sleep. Men had higher rates of FM in sleep than women (median of 39.9/h [2.94/h–1032/h] vs. median 20.3/h [0/h–792.7/h]; p Conclusion This is the first study systematically assessing FM in healthy sleepers on a quantitative base. Our data showed that FM was present in every healthy sleeper and is therefore an ubiquitous phenomenon. Of note, men are more frequently affected than women. As the rates of FM increased with age, one might suggest FM a normal physiological phenomenon of aging. Acknowledgements This study was supported by the Austrian Science Fund (KLI 236) for the project “Motor activity during sleep in health and disease” to Birgit Frauscher.

Delayed Diagnosis, Range of Severity, and Multiple Sleep Comorbidities: A Clinical and Polysomnographic Analysis of 100 Patients of the Innsbruck Narcolepsy Cohort

Narcolepsy is reported to affect 26-56/100,000 in the general population. We aimed to describe clinical and polysomnographic features of a large narcolepsy cohort in order to comprehensively characterize the narcoleptic spectrum. We performed a chart- and polysomnographybased review of all narcolepsy patients of the Innsbruck narcolepsy cohort. A total of 100 consecutive narcolepsy patients (87 with cataplexy [NC], 13 without cataplexy [N]) were included in the analysis. All subjects had either excessive daytime sleepiness or cataplexy as their initial presenting clinical feature. Age at symptom onset was 20 (6-69) years. Diagnostic delay was 6.5 (0-39) years. The complete narcolepsy tetrad was present in 36/100 patients; 28/100 patients had three cardinal symptoms; 29/100 had two; and 7/100 had only excessive daytime sleepiness. Severity varied broadly with respect to excessive daytime sleepiness (median Epworth Sleepiness Scale score: 18, range 10-24), cataplexy (8-point Likert scale: median 4.5, range 1-8), hypnagogic hallucinations (median 4.5, range 1-7), and sleep paralysis (median 3, range 1-7). Sleep comorbidity was highly prevalent and ranged from sleeprelated movement disorders (n = 55/100), parasomnias (n = 34/100), and sleeprelated breathing disorders (n = 24/100), to insomnia (n = 28/100). REM sleep without atonia or a periodic limb movement in sleep index > 5/h were present in most patients (90/100 and 75/100). A high percentage of narcoleptic patients in the present study had high frequency leg movements (35%) and excessive fragmentary myoclonus (22%). Of the narcolepsy patients with clinical features of REM sleep behavior disorder (RBD), 76.5% had EMG evidence for RBD on the multiple sleep latency test (MSLT), based on a standard cutoff of a minimum of 18% of 3-sec miniepochs. This study is one of the largest monocentric polysomnographic studies to date of patients with narcolepsy and confirms the frequent comorbidity of narcolepsy with many other sleep disorders. Our study is the first to evaluate the percentage of patients with high frequency leg movements and excessive fragmentary myoclonus in narcolepsy and is the first to demonstrate EMG evidence of RBD in the MSLT. These findings add to the growing body of literature suggesting that motor instability is a key feature of narcolepsy.

Manual Quantitative Assessment of Amplitude and Sleep Stage Distribution of Excessive Fragmentary Myoclonus

Excessive fragmentary myoclonus (EFM) consists of brief, asynchronous, twitch-like movements appearing asymmetrically in sleep. The new AASM Manual for the Scoring of Sleep and Associated Events identifies some EFM scoring criteria but does not provide amplitude criteria for scoring EFM. Older observational series have used 50 μVs. We report data from various amplitude criteria using blinded comparisons. EFMs were analyzed on the polysomnograms of 8 patients (7 men and 1 woman, mean age 57 years, range: 47-79) using a standardized protocol for sensitivity, tonus threshold, impedance, amplitude measurements, and sleep stage. The first 20 minutes each of wake, Stage 1-2, SWS, and REM were analyzed. EFMs ≥ 25, ≥ 40, and ≥ 50 microvolts (μVs) in negative deflection above the baseline were counted in tibialis anterior muscle electromyography (EMG) channels bilaterally. The mean EFM index per minute for wake, regardless of impedance, was: 7.19 ± 5.90 for ≥ 25 μV amplitude; 2.43 ± 2.02 for ≥ 40 μVs; and 2.08 ± 2.23 for ≥ 50 μVs. For sleep stages, the EFM index by stage and amplitude criteria used for measurements were: Stage 1-2: 7.38 ± 5.79 for ≥ 25 μVs; 3.13 ± 3.33 for ≥ 40 μVs; and 2.36 ± 2.66 for ≥ 50 μVs; SWS: 10.05 ± 8.04 for ≥ 25 μVs; 2.71 ± 3.13 for ≥ 40 μVs; and 1.38 ± 1.92 for ≥ 50 μVs; Total REM: 15.96 ± 11.32 for ≥ 25 μVs; 6.32 ± 4.25 for ≥ 40 μVs; and 3.94 ± 3.73 for ≥ 50 μVs; Phasic REM: 19.69 ± 15.45 for ≥ 25 μVs; 8.63 ± 7.06 for ≥ 40 μVs; and 5.52 ± 6.44 for ≥ 50 μVs; Non-phasic REM: 13.93 ± 11.31 for ≥ 25 μVs; 5.16 ± 3.57 for ≥ 40 μVs; and 3.20 ± 2.92 for ≥ 50 μVs. EFM rates increase with SWS and total REM with the highest EFM rates occurring during phasic REM. EFM rates were increased across all sleep stages when impedance was > 30 KΩ.