The localizing and lateralizing value of ictal/postictal coughing in patients with focal epilepsies.

Postictal coughing has so far been reported to indicate a temporal origin of focal epilepsy. A trend towards non-dominant hemisphere lateralization and mesial temporal localization has been suggested. However, postictal coughing has also been reported in a few patients with extratemporal epilepsies. We have retrospectively evaluated the localizing and lateralizing value of ictal/postictal coughing in 197 patients with temporal and extratemporal epilepsy who received presurgical video-EEG long-term recordings from 1999 to 2001. There was no statistical significant difference in percentage of coughing patients in both groups. However, only patients belonging to the temporal group presented with coughing as a regular element of seizure semiology (simple partial and complex partial seizures) whereas in the extratemporal group coughing occurred more sporadically. Within the temporal group a statistically significant tendency to left-sided seizure onset and a statistically not significant preponderance of mesial seizure onset was observed. Additional vegetative signs were observed only in about half of the patients. These results suggest that coughing occurs in both temporal and extratemporal lobe epilepsy and may only be indicative of temporal lobe seizure onset if representing a regular semiologic element. Coughing may be due to two different mechanisms, one dependent and the other independent from additional vegetative symptoms.     

The localizing value of ictal EEG in focal epilepsy.

OBJECTIVE: To investigate the lateralization and localization of ictal EEG in focal epilepsy. METHODS: A total of 486 ictal EEG of 72 patients with focal epilepsy arising from the mesial temporal, neocortical temporal, mesial frontal, dorsolateral frontal, parietal, and occipital regions were analyzed. RESULTS: Surface ictal EEG was adequately localized in 72% of cases, more often in temporal than extratemporal epilepsy. Localized ictal onsets were seen in 57% of seizures and were most common in mesial temporal lobe epilepsy (MTLE), lateral frontal lobe epilepsy (LFLE), and parietal lobe epilepsy, whereas lateralized onsets predominated in neocortical temporal lobe epilepsy and generalized onsets in mesial frontal lobe epilepsy (MFLE) and occipital lobe epilepsy. Approximately two-thirds of seizures were localized, 22% generalized, 4% lateralized, and 6% mislocalized/lateralized. False localization/lateralization occurred in 28% of occipital and 16% of parietal seizures. Rhythmic temporal theta at ictal onset was seen exclusively in temporal lobe seizures, whereas localized repetitive epileptiform activity was highly predictive of LFLE. Seizures arising from the lateral convexity and mesial regions were differentiated by a high incidence of repetitive epileptiform activity at ictal onset in the former and rhythmic theta activity in the latter. CONCLUSIONS: With the exception of mesial frontal lobe epilepsy, ictal recordings are very useful in the localization/lateralization of focal seizures. Some patterns are highly accurate in localizing the epileptogenic lobe. One limitation of ictal EEG is the potential for false localization/lateralization in occipital and parietal lobe epilepsies.     

The localizing value of auras in partial seizures: a prospective and retrospective study.

Doubts concerning the localizing significance of auras in partial seizures have recently been expressed. Prompted by this, we studied this issue by re-examining two groups of patients; the first, studied retrospectively, consisted of patients in whom the site of origin of the seizures was known beyond a reasonable doubt; the second, studied prospectively, comprised patients in whom specific auras were correlated with the localization of interictal epileptiform EEG abnormalities and the final diagnostic impression. The data from the retrospective series were suitable for rigorous statistical analysis. The two groups yielded similar results: the frequency of auras in partial seizures and the localizing significance of those for which large enough numbers could be collected was high. We conclude that the type of aura, when elicited by careful history-taking, provides as useful localizing, but often not lateralizing, information as the EEG and modern high-technology procedures such as CT, MRI, and PET.     

Ocular bobbing: the myth of its localizing value.

Ocular bobbing is a distinctive eye movement disorder seen in patients with pontine dysfunction. The typical phenomenon consists of abrupt, spontaneous downward jerks of the eyes with a slow return to the midposition in association with paralysis of spontaneous and reflex horizontal eye movements. Bobbing was present in a patient with acute cerebellar hemorrhage in whom no intrapontine lesions could be demonstrated. The myth that this sign is specific for intrapontine destruction has to be abandoned.     

Widespread epileptic networks in focal epilepsies: EEG-fMRI study

Purpose: To assess the extent of brain involvement during focal epileptic activity, we studied patterns of cortical and subcortical metabolic changes coinciding with interictal epileptic discharges (IEDs) using group analysis of simultaneous electroencephalography and functional magnetic resonance imaging (EEG‐fMRI) scans in patients with focal epilepsy. Methods: We selected patients with temporal lobe epilepsy (TLE, n = 32), frontal lobe epilepsy (FLE, n = 14), and posterior quadrant epilepsy (PQE, n = 20) from our 3 Tesla EEG‐fMRI database. We applied group analysis upon the blood oxygen–level dependent (BOLD) response associated with focal IEDs. Key Findings: Patients with TLE and FLE showed activations and deactivations, whereas in PQE only deactivations occurred. In TLE and FLE, the largest activation was in the mid–cingulate gyri bilaterally. In FLE, activations were also found in the ipsilateral frontal operculum, thalamus, and internal capsule, and in the contralateral cerebellum, whereas in TLE, we found additional activations in the ipsilateral mesial and neocortical temporal regions, insula, and cerebellar cortex. All three groups showed deactivations in default mode network regions, the most widespread being in the TLE group, and less in PQE and FLE. Significance: These results indicate that different epileptic syndromes result in unique and widespread networks related to focal IEDs. Default mode regions are deactivated in response to focal discharges in all three groups with syndrome specific pattern. We conclude that focal IEDs are associated with specific networks of widespread metabolic changes that may cause more substantial disturbance to brain function than might be appreciated from the focal nature of the scalp EEG discharges.     

Perioral reflex myoclonias: a controlled study in patients with JME and focal epilepsies

PURPOSE: Perioral reflex myoclonias (PORM) are obvious, frequent, but often unobserved focal seizures in different epileptic syndromes and the leading seizure type in reading epilepsy. PORMs remain often undiagnosed because the patients are not aware that these are epileptic seizures and fail to report them. Their semiology is not fundamentally different in various epileptic syndromes. METHODS: We studied the frequency of PORM in patients with juvenile myoclonic epilepsy (JME) compared with patients with focal epilepsies. Twenty-five patients with JME were investigated with a standardized neuropsychological test program and compared with 25 matched patients with focal epilepsies. Statistical significance was calculated by using Fisher's exact test. RESULTS: We found significant differences between the groups regarding both frequency of PORM and activation of epileptic discharges. These observations seem to indicate that PORM, like praxis-induced seizures, are typical traits in JME. CONCLUSIONS: PORM are more frequent in JME compared with focal epilepsies. The distinction between focal and generalized epileptic ictogenesis may be less clear than is traditionally believed.     

Psychoses of epilepsy: a study comparing the clinical features of patients with focal versus generalized epilepsies

In the literature, psychosis of epilepsy (POE) has been described as one of the most frequent psychiatric comorbidities of epilepsy, occurring particularly in association with temporal lobe epilepsy. However, the presence of such psychiatric disorders among patients with idiopathic generalized epilepsies has also been mentioned. In this study, we evaluated the clinical features of psychotic disorders in a series of patients with temporal lobe epilepsy related to mesial temporal sclerosis (TLE-MTS) and juvenile myoclonic epilepsy with the aim of describing and comparing the clinical patterns of the psychotic symptoms in such frequent and important epilepsy syndromes. POE occurred most frequently in patients with TLE-MTS (P=0.01), but no differences were observed between the groups with respect to the subtypes and core symptoms of psychoses. The clinical implications of POE in both epilepsy syndromes are discussed.     

癫痫手术前SPECT的定位价值

目的：了解单光子发射计算机断层扫描（ＳＰＥＣＴ）行局部脑血流检查在致痫灶定位中的应用价值。方法：对２４例癫痫患者行ＳＰＥＣＴ检查，结果采用目测和半定量分析两种方法进行判断。结果：１３／２４（５６％）的患者有目测的异常灌注区，其中１１／１３（８５％）与综合定位的结果相一致，半定量分析的方法可发现１２／１２的患者有异常灌注区，其中１０／１２（８３％）可得到与综合定位结果相一致的结论。统计学显示两种方法在阳性检出率和准确率上有显著差异。结论：ＳＰＥＣＴ在致痫灶的定位中有较高的应用价值，半定量分析的方法可明显提高ＳＰＥＣＴ对致痫灶的检出率，但应将检查结果与临床及其他检查资料相结合进行分析以减少假阳性率     

Mutations in KCNT1 cause a spectrum of focal epilepsies

Autosomal dominant mutations in the sodium‐gated potassium channel subunit gene KCNT1 have been associated with two distinct seizure syndromes, nocturnal frontal lobe epilepsy (NFLE) and malignant migrating focal seizures of infancy (MMFSI). To further explore the phenotypic spectrum associated with KCNT1, we examined individuals affected with focal epilepsy or an epileptic encephalopathy for mutations in the gene. We identified KCNT1 mutations in 12 previously unreported patients with focal epilepsy, multifocal epilepsy, cardiac arrhythmia, and in a family with sudden unexpected death in epilepsy (SUDEP), in addition to patients with NFLE and MMFSI. In contrast to the 100% penetrance so far reported for KCNT1 mutations, we observed incomplete penetrance. It is notable that we report that the one KCNT1 mutation, p.Arg398Gln, can lead to either of the two distinct phenotypes, ADNFLE or MMFSI, even within the same family. This indicates that genotype–phenotype relationships for KCNT1 mutations are not straightforward. We demonstrate that KCNT1 mutations are highly pleiotropic and are associated with phenotypes other than ADNFLE and MMFSI. KCNT1 mutations are now associated with Ohtahara syndrome, MMFSI, and nocturnal focal epilepsy. They may also be associated with multifocal epilepsy and cardiac disturbances.     

Migraine without aura: a population-based twin study.

To investigate the importance of genetic and environmental factors to the etiology of migraine without aura and to compare the symptomatology of migraine without aura in monozygotic and dizygotic twins, 2,680 twin pairs were recruited from the population-based Danish Twin Registry. Monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs, where at least one twin had self-reported migraine or self-reported severe headache with accompanying symptoms, were telephone interviewed by a physician. The participation rate in the telephone interview was 90%. The pairwise concordance rate was significantly higher in MZ than in DZ twin pairs (28% vs 18%). The probandwise concordance rate was 40% (95% CI, 33-48%) in MZ and 28% (95% CI, 23-33%) in DZ twin pairs. The pairwise concordance rates for the different pain characteristics and accompanying symptoms were not significantly different in MZ and DZ twin pairs. However, comparing all of the pairwise concordance rates of pain characteristics and accompanying symptoms together, MZ twin pairs were significantly more concordant than DZ twin pairs. Our data demonstrate a significant genetic factor in migraine without aura. The size of this factor is modest and the demonstration of susceptibility genes is predicted to be laborious and difficult.     

Typical and reverse bobbing: a case with localizing value

Report of a case of typical bobbing occasionally interpolated by reverse bobbing. The causative lesion, which lay in the most dorsal median portion of the pontine tegmentum, was a small primary hemorrhage, diagnosed in life by CT scanning and confirmed at necropsy. The pathological and clinical correlations of the phenomenon are discussed.     

The lateralizing and localizing value of adversion in epileptic seizures

We studied 24 patients who had adversion as the first clinical manifestation of seizures. Seizures were recorded with depth electrodes as part of the evaluation for possible surgery for epilepsy. Head rotation did not help to lateralize the epileptic focus clinically, because deviations occurred ipsilaterally to the EEG focus in some patients, and because some patients had head rotation in either direction despite a unifocal epileptogenic abnormality. Furthermore, no cortical localization was consistently linked to either direction or degree of adversion. Adversion has no consistent lateralizing or localizing value.