Nocturnal paroxysmal dystonia to sleep-related hypermotor epilepsy: A critical review.

Sleep-related paroxysmal motor episodes (SPMEs) have been described by various names, including nocturnal paroxysmal dystonia, nocturnal frontal lobe epilepsy (NFLE), and sleep-related hypermotor epilepsy. The underlying pathophysiology has been debated over the years, with these episodes assumed to be a form of paroxysmal dystonia or parasomnia versus a form of epilepsy. In most studies published on SPMEs and their variants (paroxysmal arousals, nocturnal paroxysmal dystonia, and episodic nocturnal wanderings) in the early 1990s, the authors speculated on the pathophysiology but did not commit to one idea. It was not until the mid-1990s that epilepsy became the leading prospect. We performed a narrative review of the major articles that have described this syndrome in a chronological fashion. We identified three eras, 1972-1993, 1994-1998, and 1999 to the present, each era marked by a landmark study. Our critical review of these early studies shows that the neurophysiological data supporting epilepsy as the sole basis for all SPME cases is very weak. In 1994-1995, a familial pattern of this syndrome was described and the term autosomal dominant NFLE was coined, with the authors claiming that all their patients had a form of frontal lobe epilepsy. With the exception of a few reference cases, the neurophysiological evidence that all patients had frontal lobe epilepsy was very weak. Compared to articles published on surgical series of frontal lobe epilepsy, the percentage of SPME cases with positive interictal/ictal electroencephalograms remained very low, seriously questioning the epileptic basis of the syndrome. Our critical review and analysis of the published literature shows that the evidence presented in favor of SPMEs being a homogenous focal epilepsy syndrome is very weak. Neurologists must recognize that SPMEs could be a form of movement disorder, parasomnia, or epilepsy. We recommend a pragmatic semiology-based classification of these episodes using the four-dimensional classification system.

Metabolic phenotyping of hand automatisms in mesial temporal lobe epilepsy.

PURPOSE: Hand automatisms (HA) are common clinical manifestations in mesial temporal lobe epilepsy. However, the location of the symptomatogenic zone (EZ) in HA as well as the networks involved, are still unclear. To have a better understanding of HA underlying mechanisms, we analyzed images from interictal [18F] fluorodeoxyglucose-positron emission tomography (FDG-PET) in patients with mesial temporal lobe epilepsy (mTLE). METHODS: We retrospectively recruited 79 mTLE patients and 18 healthy people that substituted the control group for the analysis. All patients underwent anterior temporal lobectomy and were seizure-free. Based on the semiology of the HA occurrence, the patients were divided into three subgroups: patients with unilateral HA (Uni-HA), with bilateral HA (Bil-HA) and without HA (None-HA). We performed the intergroup comparison analysis of the interictal FDG-PET images and compared the functional connectivity within metabolic communities. RESULTS: Our analysis showed that the metabolic patterns varied among the different groups. The Uni-HA subgroup had significant differences in the extratemporal lobe brain areas, mostly in the ipsilateral supplementary motor area (SMA) and middle cingulate cortex (MCC) when compared to the healthy control group. The Bil-HA subgroup demonstrated that the bilateral SMA and MCC areas were differentially affected, whereas in the None-HA subgroup the differences were evident in limited brain areas. The metabolic network involving HA showed a constrained network embedding the SMA and MCC brain regions. Furthermore, the increased metabolic synchronization between SMA and MCC was significantly correlated with HA. CONCLUSION: The metabolic pattern of HA was most conspicuous in SMA and MCC brain regions. Increased metabolic synchronization within SMA and MCC was considered as the major EZ of HA.

Reliability of additional reported seizure manifestations to identify dissociative seizures.

PURPOSE: Descriptions of seizure manifestations (SM), or semiology, can help localize the symptomatogenic zone and subsequently included brain regions involved in epileptic seizures, as well as identify patients with dissociative seizures (DS). Patients and witnesses are not trained observers, so these descriptions may vary from expert review of seizure video recordings of seizures. To better understand how reported factors can help identify patients with DS or epileptic seizures (ES), we evaluated the associations between more than 30 SMs and diagnosis using standardized interviews. METHODS: Based on patient- and observer-reported data from 490 patients with diagnoses documented by video-electoencephalography, we compared the rate of each SM in five mutually exclusive groups: epileptic seizures (ES), DS, physiologic seizure-like events (PSLE), mixed DS and ES, and inconclusive testing. RESULTS: In addition to SMs that we described in a prior manuscript, the following were associated with DS: light triggers, emotional stress trigger, pre-ictal and post-ictal headache, post-ictal muscle soreness, and ictal sensory symptoms. The following were associated with ES: triggered by missing medication, aura of déjà vu, and leftward eye deviation. There were numerous manifestations separately associated with mixed ES and DS. CONCLUSIONS: Reported SM can help identify patients with DS, but no manifestation is pathognomonic for either ES or DS. Patients with mixed ES and DS reported factors divergent from both ES-alone and DS-alone.

The Rolandic operculum generates different semiologies in insulo-opercular and temporal lobe epilepsies.

PURPOSE: The role of the Rolandic operculum in in mesial temporal lobe epilepsy (MTLE) is to produce oroalimentary automatisms (OAAs). In insulo-opercular epilepsy (IOE), the Rolandic operculum may produce perioral muscle clonic or tonic movements or contractions. This paper aims to confirm the symptomatogenic zone of facial symptoms in IOE and to explain this phenomenon. METHODS: A total of 45 IOE patients and 15 MTLE patients were analyzed. The patients with IOE were divided into facial (+) and (-) groups according to the facial symptoms. The interictal positron emission tomography (PET) data were compared among groups. Furthermore, electroclinical correlation, functional connectivity and energy ratio (ER) were analyzed with stereo-electroencephalography (SEEG). RESULTS: Intergroup PET differences were observed mainly in the Rolandic operculum. Electroclinical correlation showed that the Rolandic operculum was the only brain area showing any correlations. Compared with the facial (-) group, the facial (+) group showed stronger functional connectivity and a higher ER in the alpha 1, alpha 2 and beta sub-bands. In the Rolandic operculum, compared with those of the MTLE group, the h2 and ER of the facial (+) group were higher in the high frequency sub-bands. Intergroup comparison of the ER in the seizure onset zones (SOZ) showed no significant difference. SIGNIFICANCE: The symptomatogenic zone of facial symptoms in IOE is the Rolandic operculum. Seizure propagation to the Rolandic operculum generates different semiologies because of the different synchronization frequencies and energies of the sub-bands depending on the site of seizure origin. This may be due to the complex spreading pathway from the SOZ to the symptomatogenic zone.

Symptomatogenic zone and network of oroalimentary automatisms in mesial temporal lobe epilepsy.

OBJECTIVE: Oroalimentary automatisms (OAAs) are common clinical manifestations of medial temporal lobe epilepsy. Nevertheless, the location of the symptomatogenic zone of OAAs remains unclear. The generation mechanism of OAAs also has not been clarified. We attempt to explain these problems by analyzing interictal [18 F]-fluorodeoxyglucose positron emission tomography (18 FDG-PET) imaging and ictal stereo-electroencephalography (SEEG) recordings in patients with medial temporal lobe epilepsy. METHODS: Fifty-seven patients with mesial temporal lobe epilepsy were analyzed retrospectively. All underwent anterior temporal lobectomy (ATL) and were seizure-free. The patients were divided into OAA (+) and OAA (-) groups according to the occurrence of consistent stereotyped OAAs. The interictal PET data were compared with those of 18 healthy controls and were then compared between groups using statistical parametric mapping (SPM). Functional connectivity using linear regression analysis was performed between the target brain regions. To clarify the network of OAAs, ictal epileptogenicity index (EI) values, and the nonlinear correlation method h2 were performed with SEEG on patients. RESULTS: Compared to OAAs (-), the rolandic operculum was the only area with significant differences. Hippocampus and rolandic operculum showed significant correlations in the OAA (+) group (y = 0.758x+0.470, R2  = 0.456, P = 0.000). No correlation was found in the OAA (-) group (P = 0.486). The EI values of the OAA (+) group (median 0.20) were significantly higher (P < 0.0001) than those of the OAA (-) group (median 0). The h2 in the OAA (+) group (h2  = 0.23 ± 0.13) showed stronger functional connectivity (t = 6.166, P < 0.0001) than that of the OAA (-) group (h2  = 0.08 ± 0.05). SIGNIFICANCE: The rolandic operculum is most likely to be the symptomatogenic zone of OAAs. In medial temporal lobe epilepsy, unilateral functional connection from the hippocampus to the rolandic operculum during seizure onset is the basis for the generation of OAAs.

A case report of a Wada test after dominant hemisphere multiple hippocampal transections: Pathophysiology of confusion after amobarbital injection.

Dialepsis is defined as a predominant alteration of consciousness with preservation of motor tone and the ability to perform movements. While dialepsis is a common feature of both focal and generalized epilepsies, its precise symptomatogenic zone and pathogenesis remain undefined. This case report describes a patient who underwent intracarotid amobarbital procedures before and after dominant hemisphere multiple hippocampal transections. From our observations, we propose a possible pathogenesis for the generation of dialeptic seizures.