Nocturnal paroxysmal dystonia - case report.

Nocturnal paroxysmal dystonia describes a syndrome consisting of recurrent motor episodes of dystonic-dyskinetic features arising from non-rapid eye movement (NREM) sleep. In the article, the authors present female case of nocturnal paroxysmal dystonia. The patient has had attacks since her childhood and was eventually diagnosed at the age of 48. Therapy with carbamazepine considerably reduced the frequency and entent of seizures. The present case evidences that nocturnal paroxysmal dystonia still is a diagnostic challenge for clinicians. Especially, we emphasize the importance of polysomnography in the verification of the diagnosis.

[Non-epileptic paroxysmal sleep disorders]. / Trastornos paroxísticos no epilépticos durante el sueño.

Non-epileptic paroxysmal disorders during sleep are a great challenge for the clinician. It is important to know the various clinical manifestations for appropriate differential diagnosis, since alterations in sleep, mostly motor, are part of these disorders. Our paper describes the normal sleep stages and electroencephalographic characteristics and polysomnography basic data. The confusions especially with nocturnal frontal lobe epilepsy are frequent and cause unnecessary drugs administered, the emotional burden of the parents or caretakers, which is the diagnosis of epilepsy. We discuss the possible causes of diagnostic errors.

TITLE: Trastornos paroxisticos no epilepticos durante el sueño.Los trastornos paroxisticos no epilepticos durante el sueño son un gran reto para el clinico. Por ello, es importante conocer las diferentes manifestaciones clinicas que permitan llevar a cabo un diagnostico diferencial adecuado, ya que las alteraciones, sobre todo motoras en el sueño, son parte de estos trastornos. En el presente trabajo se describen las fases del sueño normal y sus caracteristicas electroencefalograficas, asi como datos basicos de la polisomnografia. Las confusiones, sobre todo con la epilepsia nocturna del lobulo frontal, son frecuentes y provocan que se administren farmacos innecesarios, asi como una carga emocional en los padres o cuidadores del paciente, que resulta del diagnostico de epilepsia. Se enuncian las posibles causas de los errores de diagnostico.

Effects of antiepileptic treatment on sleep and seizures in nocturnal frontal lobe epilepsy.

OBJECTIVE: To study the effects of antiepileptic treatment on sleep parameters and video-polysomnography (VPSG) seizures in nocturnal frontal lobe epilepsy (NFLE). METHODS: Twenty patients with a clinical and VPSG diagnosis of NFLE (baseline polysomnography [PSG]) underwent a clinical follow-up and performed a second VPSG after effective antiepileptic treatment lasting for at least 6 months. Conventional sleep measures, cyclic alternating pattern (CAP) parameters, and objective VPSG seizures were assessed in NFLE patients before and after treatment and were compared with the results of 20 age- and gender-matched control subjects. RESULTS: Antiepileptic treatment determined a partial reduction of objective VPSG seizures of approximately 25% compared to baseline condition. Alterations of most conventional sleep measures recovered normal values, but nonrapid eye movement (NREM) sleep instability remained pathologically enhanced (CAP rate, +26% compared to controls) and was associated with persistence of daytime sleepiness. CONCLUSIONS: Residual epileptic events and high levels of unstable NREM sleep can define a sort of objective resistance of both seizures and disturbed arousal system to the therapeutic purpose of the antiepileptic drugs in NFLE. This finding could determine the need for new therapeutic options in this particular form of epilepsy.

Differential diagnoses of nocturnal fear and movement paroxysm: a case report.

Recurrent nocturnal behavioural and movement paroxysms are a diagnostic challenge for the clinical pediatrician. We report on an adolescent girl who presents recurrent stereotypical nightmare-like episodes occurring during non-REM sleep stages 1-2 (N1 and N2). We discuss the differential diagnoses between epileptic and nonepileptic events and between nocturnal frontal and temporal seizures. The pathophysiological and unusual electroencephalographical features are discussed with respect to clinical features and results of interictal FDG-PET. Conclusion In case of stereotypical nightmare-like episodes in children or adolescents, an epileptic origin has to be ruled out before a parasomnia is diagnosed. In addition, a normal awake EEG or interictal sleep EEG in the diagnostic workup may not exclude an epileptic disorder. In case of nightly stereotypic motor or affective events, an epileptic disorder should be discussed.

[The borderland between epilepsy and movement disorders].

Epileptic seizures presenting as motor phenomena without concomitant conscious change may be confused with one of the paroxysmal movement disorders. Conversely, the attack of paroxysmal movement disorders may be thought to be epileptic due to a number of factors, including its sudden, unpredictable, and transient nature, its response to anticonvulsants, and the premonitory sensations preceding attacks. The distinction between epilepsy and movement disorders is further confused by the reports that these two conditions frequently occur in the same families or even in the same patients. Recent studies show that a few epilepsy and paroxysmal movement disorders are "channelopathies", indicating that they may share some common pathophysiology and a possible "overlap". A good quality of history, a trial to reproduce the motor phenomena, the application of video-EEG, polysomnography, and other electrophysiological recordings, together with regular follow-up are important for differentiating these two conditions.

Discinesias paroxísticas / Paroxysmal Diskinesias

Resumen. Introducción. Las discinesias paroxísticas consisten en trastornos del movimiento infrecuentes, que ocurren de forma brusca y recurrente, manifestadas como posiciones distónicas, movimientos coreicos, atetósicos, balísticos o una combinación de éstos. Desarrollo y conclusiones. No conocemos con exactitud su fisiopatología. Se sugiere tanto un mecanismo epiléptico como una alteración de la modulación de los ganglios basales, aunque como alteración común se plantea que se trate de canalopatías por mutaciones en genes de canales iónicos. En función del precipitante de las discinesias podremos hablar de discinesias no cinesogénicas, cinesogénicas, inducidas por ejercicio o hipnogénicas, siguiendo la última clasificación propuesta por Demirkiran y Jankovic. Además, se han descrito asociaciones como el síndrome de convulsiones infantiles y coreoatetosis paroxística o la asociación de epilepsia rolándica, distonía paroxística inducida por el ejercicio y calambre del escribiente. También se han descrito otros trastornos del movimiento paroxísticos; aunque no entraremos en detalles, se nombrarán posteriormente. Las discinesias paroxísticas también se diferencian, dependiendo de su etiología, en idiopáticas (familiares en la mayoría de los casos) y secundarias (sintomáticas de una enfermedad subyacente (AU)

Summary. Introduction. Paroxysmal dyskinesias are uncommon movements disorders that consist on recurrent brief episodes characterized by attacks with any combination of dystonia, chorea, athetosis or ballismus. Development and conclusions. The pathophysiology of paroxysmal dyskinesias is unclear at the present time. An epileptic mechanism and basal ganglia disorders have been proposed although channelopathy due to ion channel mutations have been recently suggested. These disorders were classified by Demirkiran and Jankovic into two main groups: paroxysmal kinesigenic dyskinesia if the attacks were induced by sudden movement and paroxysmal nonkinesigenic dyskinesia if they were not. In addition to these groups, two more types have been known, namely paroxysmal exercise-induced dyskinesia and hypnogenic paroxysmal dyskinesia. As well association between benign infantile familial convulsions and paroxysmal choreoathetosis, or rolandic epilepsy, episodes of exercise induced dystonia, and writers’ cramp have been described. Also others paroxysmal movements disorders have been known, wemention below. Paroxysmal dyskinesias can further be divided into idiopathic (familiar in most of the cases) or secondary cases depending on underlying cause (AU)

Autosomal dominant nocturnal frontal lobe epilepsy and mild memory impairment associated with CHRNB2 mutation I312M in the neuronal nicotinic acetylcholine receptor.

Certain paroxysmal nocturnal behaviors have been established as features of nocturnal frontal lobe epilepsy (NFLE). Despite insight into its genetics, the majority of patients with NFLE are not linked to a known mutation and clinical diagnosis remains a challenge. We describe a family presenting with stereotyped nocturnal arousals from non-rapid eye movement sleep, bilateral hand posturing, and pelvic thrusting in the mother, but subtle motor activity in the daughter, and minimal or no epileptiform EEG discharges. Despite normal IQ, there were moderate and severe verbal memory deficits in the mother and daughter, respectively. Genetic testing revealed the CHRNB2 mutation I312M in transmembrane region 3 (M3) of the neuronal nicotinic acetylcholine receptor. Phenotypic similarities in unrelated families suggest the determining role of this mutation in NFLE, whereas different inter- and intrafamilial cognitive profiles point to other factors. The absence of clear motor features of NFLE in the daughter emphasizes the shortcomings of current clinical criteria and the potential for genetic testing to further guide clinical diagnostic criteria.

[Idiopathic nocturnal frontal lobe epilepsy--an unusual epilepsy syndrome]. / Az idiopathiás nocturnalis frontális lebeny epilepszia--rendhagyó epilepsziás szindróma.

This paper provides an overview of the development of conceptions about nocturnal frontal lobe epilepsy syndrome and describes the electro-clinical characteristics, the identity of the genetic and sporadic variant, and the relationship of the EEG and clinical signs with NREM sleep specific features. The differential diagnostic difficulties and open questions on the pathomechanism are emphasized especially in relation with the lack of epileptiform EEG signs, circumscribed seizure onset zone and cognitive deficits. The relationship of frontal automatisms and NREM parasomnias are also discussed in relation of the place of nocturnal frontal lobe epilepsy among other epilepsies.

Interobserver reliability of video recording in the diagnosis of nocturnal frontal lobe seizures.

BACKGROUND: Nocturnal frontal lobe seizures (NFLS) show one or all of the following semeiological patterns: (1) paroxysmal arousals (PA: brief and sudden recurrent motor paroxysmal behavior); (2) hyperkinetic seizures (HS: motor attacks with complex dyskinetic features); (3) asymmetric bilateral tonic seizures (ATS: motor attacks with dystonic features); (4) epileptic nocturnal wanderings (ENW: stereotyped, prolonged ambulatory behavior). OBJECTIVE: To estimate the interobserver reliability (IR) of video-recording diagnosis in patients with suspected NFLS among sleep medicine experts, epileptologists, and trainees in sleep medicine. METHODS: Sixty-six patients with suspected NFLS were included. All underwent nocturnal video-polysomnographic recording. Six doctors (three experts and three trainees) independently classified each case as "NFLS ascertained" (according to the above specified subtypes: PA, HS, ATS, ENW) or "NFLS excluded". IR was calculated by means of Kappa statistics, and interpreted according to the standard classification (0.0-0.20 = slight agreement; 0.21-0.40 = fair; 0.41-0.60 = moderate; 0.61-0.80 = substantial; 0.81-1.00 = almost perfect). RESULTS: The observed raw agreement ranged from 63% to 79% between each pair of raters; the IR ranged from "moderate" (kappa = 0.50) to "substantial" (kappa = 0.72). A major source of variance was the disagreement in distinguishing between PA and nonepileptic arousals, without differences in the level of agreement between experts and trainees. CONCLUSIONS: Among sleep experts and trainees, IR of diagnosis of NFLS, based on videotaped observation of sleep phenomena, is not satisfactory. Explicit video-polysomnographic criteria for the classification of paroxysmal sleep motor phenomena are needed.

Clinical identification of the simple sleep-related movement disorders.

Simple sleep-related movement disorders must be distinguished from daytime movement disorders that persist during sleep, sleep-related epilepsy, and parasomnias, which are generally characterized by activity that appears to be simultaneously complex, goal-directed, and purposeful but is outside the conscious awareness of the patient and, therefore, inappropriate. Once it is determined that the patient has a simple sleep-related movement disorder, the part of the body affected by the movement and the age of the patient give clues as to which sleep-related movement disorder is present. In some cases, all-night polysomnography with accompanying video may be necessary to make the diagnosis. Hypnic jerks (ie, sleep starts), bruxism, rhythmic movement disorder (ie, head banging/body rocking), and nocturnal leg cramps are discussed in addition to less well-appreciated disorders such as benign sleep myoclonus of infancy, excessive fragmentary myoclonus, and hypnagogic foot tremor/alternating leg muscle activation.

Movement disorders in sleep: guidelines for differentiating epileptic from non-epileptic motor phenomena arising from sleep.

Seizures, namely in certain epileptic conditions, may be precipitated by sleep. Nocturnal frontal lobe epilepsy seizures, characterized by bizarre motor behaviour and autonomic activation, appear almost exclusively during sleep. The differential diagnosis between this condition and sleep-related non-epileptic paroxysmal motor phenomena, in particular the parasomnias, is arduous. Moreover, accepted criteria for the diagnosis of nocturnal frontal lobe seizures are lacking and even ictal scalp EEG recording could fail to disclose paroxysmal abnormalities. The clinical and polygraphic features of the different types of seizures in nocturnal frontal lobe epilepsy and of the more common non-epileptic paroxysmal events during sleep are described. The main differentiating features characterizing nocturnal frontal seizures are: onset at any age, several attacks per night at any time during the night, brief duration (s) with stereotyped motor pattern. As video-polysomnographic recordings of the attack, the gold-standard for diagnosis, are expensive and not readily available everywhere, home-made video recordings may be helpful. Further investigations on pathophysiology, genetics and epidemiology are needed to clarify the relationship between epileptic and non-epileptic sleep related paroxysmal phenomena.

Sleep-related minor motor events in nocturnal frontal lobe epilepsy.

PURPOSE: Nocturnal frontal lobe epilepsy (NFLE) is characterized by a wide spectrum of sleep-related motor manifestations of increasing complexity, ranging from major episodes to brief motor events (minor motor events, MMEs). NFLE patients may exhibit a large quantity of MMEs in the form of short-lasting stereotyped movements. Whereas major episodes are considered epileptiform manifestations, it remains unclear whether the MMEs are related to epileptiform discharges (EDs). METHODS: To study the relation between EDs and the occurrence of MMEs, we report a detailed neurophysiolgical evaluation in NFLE subjects explored by using implanted electrodes. RESULTS: The median value of ED-related movements was 71.8%. Motor expression in relation to epileptiform discharge was surprisingly variable; no peculiar expression of MMEs could be attributed to the presence of EDs. CONCLUSIONS: Our data suggest that ED-associated MMEs are extremely polymorphous, and no univocal relation to EDs can be identified. We hypothesize that MMEs are not a direct effect of epileptiform discharge (i.e., not epileptic in origin), but the result of aspecific disinhibition of innate motor patterns. We warn clinicians that the epileptic nature of minimal motor phenomena in NFLE cannot be established on the clinical phenomenology of the event.

Paroxysmal motor disorders of sleep: the clinical spectrum and differentiation from epilepsy.

The diagnosis of paroxysmal events in sleep represents a significant challenge for the clinician, with the distinction of nocturnal epilepsy from nonepileptic sleep disorders often the primary concern. Diagnostic error or uncertainty is not uncommon in this situation, particularly with respect to nocturnal frontal lobe epilepsy (NFLE), which has a variable and often unusual presentation. Such errors can be minimized if the range of nonepileptic disorders with motor activity in sleep is fully appreciated. Here we review these disorders, before discussing the important clinical and electrographic features that allow their accurate differentiation from seizures. Particular emphasis is placed on the differentiation of nocturnal frontal lobe epilepsy from non-rapid eye movement (NREM) arousal disorders and other parasomnias. The value of recording episodes with video EEG polysomnography is discussed.

Nocturnal hypermotor seizures, suggesting frontal lobe epilepsy, can originate in the insula.

PURPOSE: To report three patients with drug-resistant nocturnal hypermotor seizures (NHSs), no detectable brain lesion, and clinically defined nocturnal frontal lobe epilepsy (NFLE) or autosomal dominant NLFE (ADNFLE), whose intracerebral EEG ictal onset primarily involved the insula, rather than the mesial or orbital frontal cortex. METHODS: Fourteen to 15 intracerebral electrodes were implanted in each patient, primarily sampling the frontal lobes with 80 to 91 recording leads covering the most likely side of seizure onset, and two to six leads placed within the ipsilateral insula. Electrical stimulation was used to test the epileptic threshold of frontal and insular brain regions at the various recording sites. RESULTS: In all three patients, a low-voltage fast activity was recorded within the anterosuperior aspect of the insula at ictal onset, either in isolation, or extending to the nearby frontal operculum in the ADNFLE patient. The role of the insula was further supported in all three patients either by the presence of high-amplitude spikes that clearly predominated over that region (n = 2) or by triggering the patient's typical aura or seizure when applying an electrical stimulation at that site, selectively (n = 2). CONCLUSIONS: The anterosuperior portion of the insula might play a pivotal role in generating nocturnal hypermotor seizures in some patients with nonlesional drug-resistant epilepsy suggesting NFLE or ADNFLE. Whether these patients are amenable to successful surgery remain an open issue.