Nocturnal motor events in epilepsy: Is there a defined physiological network?

OBJECTIVE: Paroxysmal nocturnal movements in epilepsy are a recognised phenomenon, however, the mechanisms that produce them and the effect of the underlying epilepsy still remains elusive. In this study, 10 patients were studied to define the cerebral networks corresponding to these movements and explore how epileptiform activity modulated them. METHODS: We compared the change in power of the 25-250 Hz frequency band using event-related synchronization of all stereo-EEG electrodes implanted, during a baseline segment, during nocturnal movements and seizures. RESULTS: The underlying network activated during these paroxysmal movements comprised the insula, anterior cingulate, premotor areas and orbitofrontal regions. Three groups emerged, (1) complete overlap, (2) no overlap and (3) partial overlap of ERS changes of the epileptogenic zone within the proposed network and correlation of semiology between nocturnal movements and seizures. CONCLUSION: We conclude that nocturnal movements are due to a complex interplay within this physiological network of defined anatomical regions. Epileptic activity had significant impact on nocturnal movements but was not required for generation. SIGNIFICANCE: Where the semiology of the first clinical sign of a seizure consistently matches a patient's nocturnal movements, we suggest that the underlying epileptogenic zone is potentially located within this defined network.

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

Los trastornos paroxísticos no epilépticos durante el sueño son un gran reto para el clínico. Por ello, es importante conocer las diferentes manifestaciones clínicas que permitan llevar a cabo un diagnóstico 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 características electroencefalográficas, así como datos básicos de la polisomnografía. Las confusiones, sobre todo con la epilepsia nocturna del lóbulo frontal, son frecuentes y provocan que se administren fármacos innecesarios, así como una carga emocional en los padres o cuidadores del paciente, que resulta del diagnóstico de epilepsia. Se enuncian las posibles causas de los errores de diagnóstico (AU)

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 (AU)

[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.

When restless legs syndrome turns malignant.

Usually symptoms of restless legs syndrome (RLS) respond well to treatment with dopaminergic drugs, opiates, or anticonvulsant medications. Yet sometimes symptoms can be severe and become refractory, even to high-dose combination therapy. Here we present two cases of familial RLS with rigorous and unusual motor and sensory symptoms in the form of episodes of myoclonic hyperkinesias and painful sensations in addition to more characteristic features of RLS. Stepwise reduction of all RLS-and antidepressant medication down to opiate monotherapy-and subsequent opiate rotation led to an improvement of symptoms. Yet in both cases, reintroduction of low-dose dopaminergic drugs was necessary to achieve satisfactory treatment effect. We have termed this form of RLS refractory to multiple combinations of all classes of commonly used drugs malignant RLS. Therapeutically simplification and reduction of the drug scheme and opiate rotation should be considered in malignant RLS.

Insular-opercular seizures manifesting with sleep-related paroxysmal motor behaviors: a stereo-EEG study.

PURPOSE: Sleep-related complex motor seizures are a common feature of nocturnal frontal lobe epilepsy. Nevertheless, recent studies also suggest that sleep-related hypermotor seizures can originate in the insula. The present study describes the electroclinical features of eight drug-resistant epileptic patients with insular-opercular seizures manifesting with nocturnal complex motor seizures. METHODS: Patients underwent a comprehensive presurgical evaluation, which included history, interictal electroencephalography (EEG), scalp video-EEG monitoring, high-resolution magnetic resonance imaging (MRI), and intracerebral recording by stereo-EEG. KEY FINDINGS: Almost all patients reported an initial sensation consisting of viscerosensitive or somatosensory symptoms. Ictal clinical signs were represented by tonic-dystonic asymmetric posturing and/or hyperkinetic automatisms, including bimanual/bipedal activity and ballistic movements. Some patients exhibited dysarthric speech, hypersalivation, and apnea. Interictal and ictal EEG provided lateralizing information in the majority of patients. In three patients, MRI showed a focal anatomical abnormality in the insular-opercular region. Stereo-EEG ictal recordings demonstrated that the epileptic discharge involved simultaneously the insular cortex and the opercular region. Complex motor manifestations appeared when the ictal discharge showed an extrainsular spreading to frontomesial regions (cingulum, superior frontal gyrus, and supplementary motor area) and/or to internal and neocortical temporal lobe structures. Six patients received an insular-opercular cortical resection; three of them are seizure free (minimum follow-up 24 months) and in one a marked reduction in seizure frequency was obtained. Two patients have been operated on recently. Histology revealed a focal cortical dysplasia in three patients. One patient excluded from surgery died for sudden unexpected death in epilepsy during sleep. SIGNIFICANCE: Our data strengthen the concept that sleep-related complex motor attacks can originate in the insula, and provide useful electroclinical information to differentiate this localization from those with similar clinical characteristics. Furthermore, this study indicates that in these drug-resistant patients, surgical treatment represents a highly effective treatment option.

[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.

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.

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.

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.

[Nocturnal paroxysmal dystonia, movement disorder and epilepsy]. / Distonía paroxística nocturna, trastorno del movimiento y epilepsia.

INTRODUCTION: Nocturnal paroxysmal dystonia (NPD) is a disorder which appears during sleep. It is characterized by generally brief paroxysmal motor events which are complex when clinically expressed and are often repetitive. The origin of this disorder has been a matter for discussion for some time. Initially it was considered a specific movement disorder, but recently it has been suggested that it is epileptic in nature. CASE REPORT: In this study we present the case of a patient who is hospitalized in the Unit for epileptic surgery, suffering from epilepsy which does not respond to medical treatment and requires surgery. The patient is treated with conventional methodology, prolonged and continuous presurgical videoelectroencephalographic monitoring. EEG registers were used via electrodes placed in the scalp and skull, electrodes placed in the skull on adequate indication. Two types of perfectly defined electroclinical events occurred: some not epileptic and others clearly epileptic. On one occasion a convulsive tonic clonic epileptic crisis was recorded typical of frontal focal origin preceded by non epileptic motor phenomena. CONCLUSION: The presence of paroxysmal motor episodes during sleep, atypical as a form of epilepsy, the absence of unquestionable specific data in the EEG, and in the light of our discoveries, force us to consider the possibility that NPD is in fact a form of epilepsy caused in a reflex manner by a specific type of movement disorder during sleep, and whose origin should be more widely discussed.

From nocturnal paroxysmal dystonia to nocturnal frontal lobe epilepsy.

Nocturnal paroxysmal dystonia (NPD) is the term used to describe motor attacks characterized by complex behavior, with dystonic-dyskinetic or ballic movements arising from NREM sleep. NPD together with paroxysmal arousals (PA), the briefest attacks, and episodic nocturnal wanderings (ENW), the most prolonged ones, constitute nocturnal frontal lobe epilepsy (NFLE). PA are sudden awakenings associated with stereotyped dystonic-dyskinetic movements, sometimes accompanied by screaming and a frightened expression. ENW are episodes of agitated ambulation, with complex, sometimes violent, motor behavior and dystonic postures involving head, trunk and limbs. NPD, PA and ENW coexist in most patients. NFLE is predominant in males and usually begins during adolescence. A familial recurrence of parasomnias in NFLE patients is much more common than in the general population. Autosomal dominant inheritance has been documented in 6% of our cases. Few patients present personal antecedents or positive neuroradiological findings. Seizures are frequent, occurring every or almost every night, many times per night. Interictal wake and sleep EEG tracings are often normal and ictal epileptic activity is recorded in a relatively small number of cases. Carbamazepine controls or significantly reduces seizures in about 70% of cases; the remainder are drug-resistant. Videopolysomnographic recordings, showing stereotyped abnormal movements during attacks, are mandatory to confirm the diagnosis of NFLE.