Semiological seizure classification

Surgical treatment of epilepsy with chronic cerebral granuloma caused by Schistosoma japonicum

PURPOSE

To study the surgical treatment of epilepsy with cerebral granuloma caused by Schistosoma japonicum.

METHODS

Two hundred fifty cases of epilepsy caused by cerebral schistosomiasis from 1955 to 2004 were analyzed retrospectively.

RESULTS

There were no deaths. Follow-up of 196 cases for 4-5 years after operation demonstrated that 180 cases (92%) were seizure-free or well-controlled.

CONCLUSIONS

Surgical treatment should be considered when drug therapy fails to control epilepsy or the lesion shows mass effect. Intraoperative electrocorticography monitoring is helpful to define the extent of the resection of the lesion.

The added value of [18F]-fluoro-D-deoxyglucose positron emission tomography in screening for temporal lobe epilepsy surgery

PURPOSE

[18F]-Fluoro-d-deoxyglucose positron emission tomography (FDG-PET) is an expensive, invasive, and not widely available technique used in the presurgical evaluation of temporal lobe epilepsy. We assessed its added value to the decision-making process in relation to other commonly used tests.

METHODS

In a retrospective study of a large series of consecutive patients referred to the national Dutch epilepsy surgery program between 1996 and 2002, the contribution of FDG-PET, magnetic resonance imaging (MRI), and video-electroencephalogram (video-EEG) monitoring findings, alone or in combination, to the decision whether to perform surgery was investigated. The impact of FDG-PET was quantified by comparing documented decisions concerning surgery before and after FDG-PET results.

RESULTS

Of 469 included patients, 110 (23%) underwent FDG-PET. In 78 of these patients (71%), FDG-PET findings led clinicians to change the decision they had made based on MRI and video-EEG monitoring findings. In 17% of all referred patients, the decision regarding surgical candidacy was based on FDG-PET findings. FDG-PET was most useful when previous MRI results were normal (p < 0.0001) or did not show unilateral temporal abnormalities (p < 0.0001), or when ictal EEG results were not consistent with MRI findings (p < 0.0001) or videotaped seizure semiology (p = 0.027). The positive and negative predictive values for MRI and video-EEG monitoring, which ranged from 0.48 to 0.67, were improved to 0.62 to 0.86 in combination with FDG-PET.

CONCLUSIONS

In patients referred for TLE surgery, FDG-PET findings can form the basis for deciding whether a patient is eligible for surgery, and especially when MRI or video-EEG monitoring are nonlocalizing.

Dissociation of short- and long-term face memory: Evidence from long-term recency effects in temporal lobe epilepsy

We tested whether memory deficits in temporal lobe epilepsy (TLE) are better described by a single- or dual-store memory model. To this aim, we analyzed the influence of TLE and proactive interference (PI) on immediate and 24-h long-term recency effects during face recognition in 16 healthy participants and 18 right and 21 left non-surgical TLE patients. PI in healthy participants or TLE erased the long-term recency effect, but left the immediate recency effect unaffected. Although the immediate recency effect was still visible in right TLE patients, the number of detected recency items during immediate recognition was decreased in right TLE compared to left TLE. Right TLE was also related to decreased detection of pre-recency items during delayed recognition compared to left TLE, and decreased detection of pre-recency items during immediate recognition under PI. The results show that the temporal lobes are necessary for the long-term recency effect, but not for the immediate recency effect, and thus speak for a dissociation of short- and long-term memory for faces. Right TLE is related to more severe long-term memory deficits than left TLE and is also related to additional short-term memory deficits for faces.

What is epilepsy? Clinical perspectives in the diagnosis and treatment

SUMMARY

The CINNR International Conference, "An Overview of Epilepsy Research: What, Where, When, and Why?," was designed to introduce epilepsy to the nonclinician interested in epilepsy research. This article discusses the clinical aspects of epilepsy, defines clinical terms associated with epilepsy and seizure disorders, and outlines the scope of the clinical problem and the issues that need clarification from a clinical perspective. Most importantly, it is hoped that this article will put a human face on this common disease.

Age-Dependent Seizure Semiology in Temporal Lobe Epilepsy

OBJECTIVE

To examine the effects of age on different aspects of temporal lobe seizure semiology.

METHODS

We performed a video analysis of 605 archived seizures from 155 consecutive patients (age 10 months to 49 years) selected by seizure freedom after temporal lobectomy. Eighty patients had hippocampal sclerosis (HS). Beside semiological seizure classification, we assessed age dependency of several axes of seizure semiology: (1) aura, (2) number of different lateralizing signs, occurrence of ictal (3) emotional signs, (4) autonomic symptoms, (5) automatisms, and (6) secondary generalization as well as (7) the ratio of motor seizure components.

RESULTS

From the 155 patients, 117 reported aura, 39 had ictal emotional signs, 51 had autonomic symptoms, 130 presented automatisms, while 18 patients showed secondary generalization at least once during their seizures. Altogether 369 (median: 2/patient) different lateralizing signs were recorded. Frequency of HS (p < 0.001), ictal automatisms (p < 0.001), secondary generalization (p = 0.014), number of different lateralizing signs (p < 0.001) increased while the ratio of motor seizure component (p = 0.007) decreased by age. Auras, emotional symptoms, and autonomic signs occurred independently of patients' ages. Hippocampal sclerosis adjusted linear models revealed that the frequency of automatisms and secondarily generalized seizures as well as the number of different lateralizing signs are HS-independent significant variables.

CONCLUSION

Our findings support that brain maturation significantly influences the evolution of some important aspects (motor seizures, lateralizing signs) of temporal lobe seizure semiology. Conversely, other aspects (aura, emotional, and autonomic signs) are independent of the maturation process. This is the first report investigating age dependency of epileptic seizure semiology comparing all age groups.

Developmental outcome after epilepsy surgery in infancy

OBJECTIVES

Our goals were to determine the effect of epilepsy surgery in infants (<3 years of age) on development and describe factors associated with postoperative developmental outcome.

METHODS

We identified 50 infants among 251 consecutive pediatric patients (<18 years old) undergoing epilepsy surgery. Charts were reviewed for clinical data and neurodevelopmental testing with the Bayley Scales of Infant Development. A developmental quotient was calculated to compare scores of children at different ages.

RESULTS

Complete data were available on 24 of 50 infants. Surgeries included 14 hemispherectomies and 10 focal resections. Seventeen patients became seizure free; 5 patients had >90% seizure reduction, 1 had >50% seizure reduction, and 1 had no change. The developmental quotient indicated modest postoperative improvement of mental age. The preoperative and postoperative development quotients correlated well. Younger infants had a higher increase in developmental quotient after surgery. Patients with epileptic spasms were younger and had a lower developmental quotient at presentation, but increase in developmental quotient was higher in this subgroup.

CONCLUSIONS

After surgery, seizure frequency and developmental quotient improved. Developmental status before surgery predicted developmental function after surgery. Patients who were operated on at younger age and with epileptic spasms showed the largest increase in developmental quotient after surgery.

Semiological seizure classification: before and after video-EEG monitoring of seizures

The study objective was to assess the applicability and reliability of the semiological seizure classification in children with epilepsy in outpatient clinics. Ninety patients (age range, 2-16 years) who experienced clinical seizures during prolonged video-electroencephalogram (EEG) monitoring were evaluated. Semiological seizure classification was performed, first based on history obtained from parents of the patient during outpatient follow-up visits and then based on video EEG-monitoring. Kappa statistics (kappa) were used to evaluate the consistency of the two rounds of semiological seizure classification. Classification based on history yielded the following distribution: simple motor seizures (66.3%), aura (28%), complex motor seizures (15.8%), special seizures (15.8%), dialeptic seizures (9.3%), and autonomic seizures (3.7%). Classification based on video EEG-monitoring yielded a different distribution: simple motor seizures (55.7%), complex motor seizures (26.9%), automotor seizures (26.9%), aura (23%), dialeptic seizures (22.1%), special seizures (9.6%), and autonomic seizures (1.9%). Negative myoclonic seizures (kappa = 1, P = 0.000) and hypermotor seizures (kappa = 0.85, P = 0.000) had excellent consistency; somatosensory aura (kappa = 0.26, P = 0.012) and automotor seizures (kappa = 0.28, P = 0.004) had the lowest consistency. The families or doctors often defined simple motor seizures (decrease of 10.6% from before to after monitoring, kappa = 0.44); the proportion of complex motor seizures changed rather from before to after monitoring (11.1%, kappa = 0.33). Generally, parents can describe seizures quite well. We suggest that semiological seizure classification is a reliable method applicable for everyday use during outpatient visits, especially if seizure semiology is evaluated individually for each component or if the semiological seizure classification is modified or refined for some seizure components (tonic, clonic, versive, conscious, automotor seizures).

Lateralizing significance of quantitative analysis of head movements before secondary generalization of seizures of patients with temporal lobe epilepsy

PURPOSE

To quantitatively evaluate the lateralizing significance of ictal head movements of patients with temporal lobe epilepsy (TLE).

METHODS

We investigated EEG-video recorded seizures of patients with TLE, in which the camera position was perpendicular to the head facing the camera in an upright position and bilateral head movement was recorded. Thirty-eight seizures (31 patients) with head movement in both directions were investigated. Ipsilateral and contralateral head movements were defined according to ictal EEG. Head movements were quantified by selecting the movement of the nose in relation to a defined point on the thorax (25/s) in a defined plane facing the camera. The duration of the head version was determined independently of the camera angle. The angle, duration, and angular speed of the head movements were computed and inter and intrasubject analyses were performed (Wilcoxon rank sum).

RESULTS

Ipsilateral movement always preceded contralateral movement. The positive predictive value was 100% for movement in both directions. The duration of contralateral head version was significantly longer than ipsilateral head movement (6.4 +/- 4.1 s vs. 3.9 +/- 3.1 s, p<0.001). The angular speed of both movements was similar (15.5 +/- 12.1 deg/s vs. 17.3 +/- 13.0 deg/s).

CONCLUSION

The quantitative analysis shows the importance of sequence in the seizure's evolution and duration, but not angular speed for correct lateralization of versive head movement. This quantitative method shows the high lateralizing value of ictal lateral head movements in TLE.

Localizing and lateralizing value of behavioral change in childhood partial seizures

OBJECTIVE

To describe clinical characteristics as well as localizing and lateralizing value of behavioral change (BC) at the onset of childhood seizures.

METHODS

Five hundred forty-one videotaped seizures of 109 consecutive patients < or = 12 years with partial epilepsy and postoperatively seizure-free outcome were analyzed. Behavioral change (the first clinical feature of a certain seizure with a sudden change in the child's behavior) was evaluated by two independent investigators.

RESULTS

Thirty-three (30%) patients showed BC at least once during their seizures. Behavioral changes appeared in arrestive form in 19 and with affective activities in 18 children; four patients produced both kinds of BCs, separately. Arrest-type BC happened in 16 of 50 children with right- and 3 of 59 patients with left-sided seizure onset zone (p < 0.001). Affective-type BC was observed in 17 of 67 temporal lobe epilepsy patients while it happened in only 1 of 42 children with extratemporal lobe epilepsy (p = 0.001).

CONCLUSIONS

Arrest-type BC lateralizes to the right hemisphere, while affective-type BC localizes to the temporal lobe in childhood partial seizures. Type of BCs can add important information to the presurgical evaluation of young children with refractory partial epilepsy.

Face memory in MRI-positive and MRI-negative temporal lobe epilepsy

PURPOSE

Effects of MRI-positive (MRI(+)) as compared to MRI-negative (MRI(-)) temporal lobe epilepsy (TLE) on face memory are not yet known.

METHODS

We studied 24 MRI(-) (11 right/13 left) and 20 MRI(+) (13 right/7 left) TLE patients, 12 generalized epilepsy patients, and 12 healthy subjects undergoing diagnostic workup with 24-72-h Video-EEG-monitoring. Twenty faces were shown, and had to be recognized from 40 faces immediately and after a 24-h delay.

RESULTS

MRI(+) and MRI(-) right TLE (RTLE) patients showed deficits in face recognition compared to controls or generalized epilepsy, consistent with right temporal lobe dominance for face recognition. MRI(+) RTLE patients had deficits in both immediate and delayed recognition, while MRI(-) RTLE patients showed delayed recognition deficits only. The RTLE groups showed comparable delayed recognition deficits. Separate analyses in which the MRI(+) group included patients with hippocampal sclerosis only, did not alter results. Furthermore, MRI(-) RTLE had a worse delayed recognition than MRI(-) left TLE (LTLE). On the other hand, MRI(+) RTLE did not differ from MRI(+) LTLE in delayed recognition. Combining MRI(-) and MRI(+) TLE groups, we found differences between RTLE and LTLE in delayed, but not immediate face recognition.

CONCLUSIONS

Our results suggest that a delayed recognition condition might be superior to immediate recognition tests in detecting face memory deficits in MRI(-) RTLE patients. This might explain why former studies in preoperative patients did not observe an immediate face recognition dominance of the right temporal lobe when combining MRI(-) and MRI(+) TLE patients. Our data further point to an important role of the right mesial temporal region in face recognition in TLE.

Cognitive phenotypes in temporal lobe epilepsy

The objective of this study is to determine if distinct cognitive phenotypes could be identified in temporal lobe epilepsy. Epilepsy patients (n = 96) and healthy controls (n = 82) underwent comprehensive neuropsychological assessment. Adjusted (age, gender, and education) test scores for epilepsy subjects were grouped into cognitive domains (intelligence, language, visuoperception, immediate and delayed memory, executive function, and cognitive/psychomotor speed). Cluster analysis revealed three distinct cognitive profiles types: (1) minimally impaired (47% of subjects); (2) memory impaired (24%); and (3) memory, executive, and speed impaired (29%). The three cluster groups exhibited different patterns of results on demographic, clinical epilepsy, brain volumetrics, and cognitive course over a 4-year interval. The specific profile characteristics of the identified cognitive phenotypes are presented and their implications for the investigation of the neurobehavioral complications of epilepsy are discussed.

Sex differences in face recognition memory in patients with temporal lobe epilepsy, patients with generalized epilepsy, and healthy controls

The influence of sex on face recognition memory was studied in 49 patients with temporal lobe epilepsy, 20 patients with generalized epilepsy, and 32 healthy controls. After learning 20 faces, serially presented for 5 seconds each, subjects had to recognize the 20 among 40 faces (including 20 new faces) immediately and 24 hours later. Women had better face recognition than men, with no significant differences between groups. Women's advantage was due mainly to superior delayed recognition. Taken together, the results suggest that sex has a similar impact on face recognition in patients with epilepsy and healthy controls, and that testing delayed face recognition raises sensitivity for sex differences. The influence of sex on face recognition in patients with epilepsy should be acknowledged when evaluating individuals or comparing groups.

Cyclical excitability of the motor cortex in patients with catamenial epilepsy: A transcranial magnetic stimulation study

PURPOSE

The pathophysiology of catamenial epilepsy is still unclear. Therefore, we investigated the cortical excitability of women with catamenial epilepsy during different phases of the menstrual cycle.

METHODS

Using transcranial magnetic stimulation, six patients suffering from catamenial epilepsy were investigated during ovulatory cycles. On days 8, -14, -7 and 2 of the cycle (day 1 being the first day of menstrual bleeding), resting motor threshold (RMT), cortical silent period (CSP), intracortical inhibition (ICI) and intracortical facilitation (ICF) were investigated. The non-parametric Friedman-test for multiple comparisons and Wilcoxon signed rank test were used for statistical analysis.

RESULTS

Five patients suffered from focal epilepsy (three right hemispheric, one bitemporal, one unknown origin) and one patient had idiopathic generalized epilepsy. All patients experienced perimenstrual seizure clustering and two also showed an increased seizure frequency during the luteal phase. In the right hemispheres there was a significant change of CSP duration in the course of the menstrual cycle (chi(2)=8.3, P=0.041), due to a shorter CSP during the luteal phase (Z=-2.0, P=0.043) and menstruation (Z=-2.2, P=0.028) as compared to the follicular phase. There was no significant variation of CSP in the left hemispheres. RMT, ICI and ICF showed no significant changes in the course of the menstrual cycle.

CONCLUSIONS

The CSP changes suggest a decreased inhibition involving GABA-ergic neurotransmission during the luteal phase and menstruation. These TMS alterations correlated with the clinical course of the epilepsies and were found in the hemispheres containing the majority of the epileptogenic zones.

The clinical-electrographic expression of infantile seizures

PURPOSE

To describe the electro-clinical expression of seizures in infants (1-24 months).

METHODS

We reviewed the video and EEG files of all infantile seizures recorded at Children's Memorial Hospital, Chicago, IL, from 2000 to 2005. Electrographic and clinical features were entered into separate databases. The electrographic component of the database analyzed the predominant location and pattern at onset, the evolution, the termination and the duration of each seizure. The clinical data sheet included 25 items. Each seizure was assigned to a specific category according to its most prominent clinical feature, according to the opinion of both observers.

RESULTS

Thirteen seizure types were identified. In a significant number of cases, the EEG correlate could not be predicted on the basis of clinical observations only. Generalized seizures were observed, on average, at a later age than focal seizures. Excluding spasms, the mean duration of seizures was short (36 s).

CONCLUSIONS

The results of this study are useful in describing the clinical and electrographic repertoire of infantile seizures. The findings show that video-EEG recordings in infants with frequent, recurrent seizures are useful by fully allowing complete recognition of subtle events, and in fully categorizing the true nature of the ictus. Video-EEG findings and accurate seizure classification may add fundamental information with regards to epilepsy syndrome diagnosis and specific treatment options, including surgery.

Are absences truly generalized seizures or partial seizures originating from or predominantly involving the pre-motor areas?

In both the current (1981) ILAE Classification of Epileptic Seizures and the recently Proposed Diagnostic Scheme for People with Epilepsy and Epileptic Seizures, typical absence seizures are defined as generalized seizures, implying widespread subcortical and cortical neuronal involvement from onset with impairment of consciousness as the clinical hallmark. Clinical observations from three patients and clinical and experimental data from the literature suggest, however, that: (1) consciousness is retained in many typical absences; (2) the true hallmark of these seizures is arrest of motor initiation due to disturbance of pre-motor area frontal-lobe function; (3) typical absences and partial seizures from these areas may show similar clinical and EEG features and involve the same neuronal circuits. The neuronal system primarily involved in these seizures consists of a relatively limited cortico-thalamo-cortical circuit, including the reticular thalamic nucleus, the thalamocortical relay and the predominantly anterior and mesial frontal cerebral cortex, with the cortex probably acting as the primary driving site. Typical absences thus should not be classified or defined as generalized seizures, particularly since neuropathological and imaging studies increasingly argue for localized structural abnormalities, even in idiopathic or primary generalized epilepsy. These observations further highlight the intrinsic weaknesses of the current classification system for seizures and support further adaptations of the diagnostic system currently under development.

Basic principles of the ILAE syndrome classification

The basic principles of the ILAE syndrome classification can be summarised as: clear definitions; reference to the seizure classification; expert consensus based on literature research; providing a taxonomy rather than a diagnostic manual; use of the dichotomies generalised versus localisation-related and idiopathic versus symptomatic; openness for the incorporation of new findings; and promotion of nosological thought. In fact, the publication of the classification stimulated research, especially in the fields of genetics, reflex epileptic mechanisms and advanced imaging, which will probably lead to a major revision of the nosology of epilepsies. Both localisation-related and "generalised" idiopathic epilepsies are about to be understood as related variants of system disorders of the brain, with an ictogenesis making pathological use of existing functional anatomic networks.

Lateralizing value of postictal automatisms in temporal lobe epilepsy

PURPOSE

To describe clinical characteristics and lateralizing value of postictal automatisms in patients with temporal lobe epilepsy (TLE).

METHODS

One hundred and ninety-three videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed. Ictal as well as postictal (manual, oral and speech) automatisms were monitored.

RESULTS

Thirty-four (62%) of the 55 patients showed PA at least once during their seizures. Postictal automatism was observed in 70 (36%) attacks as manual (21%), oral (13%) or speech (9%) automatisms. Fifteen seizures contained a combination of two different postictal automatisms. The presence of postictal oral automatisms did not lateralize the seizure onset zone (p=0.834). Speech automatisms (repetitive verbal behavior) occurred more frequently after left-sided seizures (p=0.002). Postictal unilateral manual automatism showed no lateralizing value occurring by the ipsilateral hand in 10 and the contralateral upper limb in 6 seizures (p=0.454).

CONCLUSION

: Postictal automatism is a relatively frequent phenomenon in TLE. Postictal speech automatism lateralizes the seizure onset zone to the left hemisphere. Our observation can help the presurgical evaluation of TLE because verbal perseveration frequently occurs spontaneously, even in seizures without appropriate postictal language testing.

Proven startle-provoked epileptic seizures in childhood: semiologic and electrophysiologic variability

PURPOSE

To delineate further the clinical and electrophysiologic features of proven startle-provoked epileptic seizures (SPESs) in children.

METHODS

Clinical, neuroradiologic, and neurophysiologic data of 22 consecutive patients with SPESs were analyzed. Eighty-nine SPESs were documented by video-EEG and evaluated with respect to semiology and ictal and interictal EEG findings.

RESULTS

Mean age was 68 months (10-178 months). Most children had severe mental retardation (86%). Neuroimaging demonstrated diffuse cerebral abnormalities in 15 of 19. Somatosensory evoked potentials revealed cortical abnormalities in 10 of 13 children. The underlying causes were heterogeneous. Only two patients were normally developed. Seizure frequency was usually high (>10/day). Two children had less frequent SPESs (two per month; two per week). Seizures were easily precipitated by sudden sound (n=15), unexpected touch (n=3), or both (n=4). The most common semiologic findings (50%) were generalized tonic seizures or those characterized by a predominant tonic phase, followed in frequency by myoclonic seizures (36%), which were generalized in seven, and unilateral in one. Generalized clonic seizures were observed in one. A complex seizure spread was documented in two children. The most common ictal EEG finding (60%) was a diffuse electrodecremental pattern (DEP). Generalized spike/polyspike waves were found in five and focal discharges in four.

CONCLUSIONS

Our results imply that startle epilepsy is not a uniform epileptic entity. We were able to demonstrate a number of distinct patterns of SPESs, characterized by clinical, semiologic, and electrophysiologic features. Considering the high diversity of SPES patients, a common underlying pathophysiologic mechanism seems unlikely.

Classification of partial seizure symptoms in genetic studies of the epilepsies

OBJECTIVES

To develop standardized definitions for classification of partial seizure symptoms for use in genetic research on the epilepsies, and evaluate inter-rater reliability of classifications based on these definitions.

METHODS

The authors developed the Partial Seizure Symptom Definitions (PSSD), which include standardized definitions of 41 partial seizure symptoms within the sensory, autonomic, aphasic, psychic, and motor categories. Based on these definitions, two epileptologists independently classified partial seizures in 75 individuals from 34 families selected because one person had ictal auditory symptoms or aphasia. The data used for classification consisted of standardized diagnostic interviews with subjects and family informants, and medical records obtained from treating neurologists. Agreement was assessed by kappa.

RESULTS

Agreement between the two neurologists using the PSSD was "substantial" or "almost perfect" for most symptom categories.

CONCLUSIONS

Use of standardized definitions for classification of partial seizure symptoms such as those in the Partial Seizure Symptom Definitions should improve reliability and accuracy in future genetic studies of the epilepsies.

Electrode manipulation automatism during temporal lobe seizures

OBJECTIVE

To describe clinical characteristics and lateralizing value of peri-ictal electrode manipulation automatism (EMA) in patients with temporal lobe epilepsy (TLE) and compare our data with ictal manual automatisms described in the literature.

METHODS

Two-hundred and five videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed and EMA (tugging, scratching or adjusting the electrodes and cables) were monitored.

RESULTS

Twenty-eight (51%) patients showed EMA during 47 (23%) seizures. Ictal start was noted in 22 seizures and in 19/22 cases EMA finished before the end of seizure. Ictal EMAs were always associated with automotor seizure components. During 25 seizures, exclusively postictal EMAs were observed. Electrode manipulation was presented during 24/112 left-sided and 23/93 right-sided seizures (p = 0.742). Peri-ictal EMA was unilateral (completed by one hand) in 24/47 seizures (10 ictal, 14 postictal); it was done by the hand ipsilateral to the seizure onset zone in 17/24 and by contralateral hand in 7/24 cases (p = 0.064). We observed concomitant contralateral dystonic posturing during 3/10 seizures with unilateral ictal EMA. Unilateral hand automatism, temporally independent from the EMA appeared in 30 (64%) of the 47 seizures.

CONCLUSION

Peri-ictal EMA is a frequent phenomenon but shows no lateralizing value in TLE. The mechanism of EMA is in many ways dissimilar from that of earlier described manual automatisms.

Cryptogenic localization-related epilepsy with childhood onset: The problem of definition and prognosis

BACKGROUND

Up to one-third of children with epilepsy are diagnosed with cryptogenic localization-related epilepsy (CLRE). CLRE is a large nonspecific category within the ILAE classification. For this population no unequivocal prognosis exists.

METHODS

Twenty-five articles describing aspects of CLRE were included in this review.

RESULTS

As a result of the progress in epilepsy research, as well as more advanced investigation in individual cases, the population with CLRE constantly changes. Also, disagreement on interpretation of the classification has resulted in striking differences between the populations described. High remission rates are reported, but relapse occurs frequently, leaving the long-term prognosis unforeseeable. This is reflected in academic and psychosocial prognosis, which is described to be problematic in CLRE specifically. Possible prognostic factors of CLRE in children have been identified: age at onset, seizure semiology, seizure frequency, intractability, interictal epileptiform activity on EEG, and premorbid IQ. These factors are explored to define subgroups within the CLRE population.

DISCUSSION

Prospective studies on well-defined CLRE cohorts are needed to identify factors that distinguish various prognostic subgroups. Specific attention should be focused on course of the epilepsy, scholastic achievement, and psychosocial outcome.

Phenotype definition in epilepsy

Phenotype definition consists of the use of epidemiologic, biological, molecular, or computational methods to systematically select features of a disorder that might result from distinct genetic influences. By carefully defining the target phenotype, or dividing the sample by phenotypic characteristics, we can hope to narrow the range of genes that influence risk for the trait in the study population, thereby increasing the likelihood of finding them. In this article, fundamental issues that arise in phenotyping in epilepsy and other disorders are reviewed, and factors complicating genotype-phenotype correlation are discussed. Methods of data collection, analysis, and interpretation are addressed, focusing on epidemiologic studies. With this foundation in place, the epilepsy subtypes and clinical features that appear to have a genetic basis are described, and the epidemiologic studies that have provided evidence for the heritability of these phenotypic characteristics, supporting their use in future genetic investigations, are reviewed. Finally, several molecular approaches to phenotype definition are discussed, in which the molecular defect, rather than the clinical phenotype, is used as a starting point.

Idiopathic generalized epilepsies: clinical and electroencephalogram diagnosis and treatment

This review concentrates on the principles of the clinical and electroencephalogram diagnosis of idiopathic generalized epilepsies and their treatment. The electroclinical variability of the main seizure types is detailed and particular emphasis is placed on the differential diagnosis from other seizures and nonepileptic conditions that is essential for the optimal management of these patients. The authors review the various idiopathic generalized epilepsy subsyndromes and conditions that are included in both the 1989 International League Against Epilepsy classification system and the recently proposed International League Against Epilepsy scheme, but also syndromes and forms that have not been formally recognized. Finally, the authors describe the principles of antiepileptic drug treatment with the old and newer drugs, and their specific indications and contraindications in the various syndromes and seizure types.

Optimal window for ictal blood flow mapping. Insight from the study of discrete temporo-limbic seizures in rats

RATIONALE

Measurement of local cerebral blood flow (LCBF) is routinely used to locate the areas involved in the generation and spread of seizures in epileptic patients. Since the spatial distribution and extent of ictal LCBF depends on the epileptogenic network, but also on the timing of injection of tracer, we used a rat model of amygdala kindled seizures to follow time-dependent changes in the distribution of seizure-induced LCBF changes.

METHODS

Rats were implanted with a left amygdala electrode and were stimulated until reaching stage 1. LCBF was measured by the quantitative [14C]iodoantipyrine autoradiographic technique. The tracer was injected either at 15 s before seizure induction (early ictal) or simultaneously with the amygdala stimulation (ictal) in rats undergoing a stage 0 or 1 seizure.

RESULTS

During stage 0 seizures, LCBF rates increased significantly ipsilaterally in medial and central amygdala and substantia nigra. During stage 1 seizures, LCBF increased unilaterally in amygdala, piriform cortex, substantia nigra, ventral tegmental area and cerebellum and bilaterally in several limbic and subcortical structures, excepted in hippocampus and pallidum. When pooling stages 0 and 1 but considering only tracer injection time, discrete LCBF changes occurred ipsilaterally in amygdala and substantia nigra at early ictal time. At true ictal time, significant changes occurred in several subcortical structures bilaterally while limbic structures displayed more localized and lateralized changes.

CONCLUSION

LCBF mapping appears unable to identify in rats the ictal onset zone of clinically significant amygdala-triggered seizures (stage 1), while the study of sub-clinical seizures (stage 0) allowed to correctly locate the amygdala onset of the seizures within the limbic network. Compared to human SPECT studies, this work confirms that some ictal hyperperfused areas belong to the spreading network rather than to the epileptogenic zone. The spatial recruitment of remote subcortical structures could be further investigated to strengthen the rationale of therapeutic stimulation of basal ganglia in drug-resistant epilepsies.

Neuroethology application for the study of human temporal lobe epilepsy: from basic to applied sciences

The aim of this investigation was to apply neuroethology to the study of human temporal lobe epilepsy (TLE). For this purpose, 42 seizures in 7 patients recorded during video/EEG monitoring (1997-1998) were analyzed by means of a behavioral glossary containing all behaviors. Video recordings were reobserved, and all patients' behaviors were annotated second-by-second. Data were analyzed using Ethomatic software and displayed as flowcharts including frequency, mean duration, and sequential statistic interaction of behavioral items (chi2 > or = 10.827, P<0.001). Flowcharts of (1) a group of seizures from a single patient, (2) the sum of four seizures per patient of two patients with right and five patients with left TLE, and (3) the comparison of left versus right TLE are shown. Well-established data in the literature were confirmed, such as aura (especially epigastric), contralateral lateralization value of dystonia and version, consciousness and language alterations in ictal and postictal periods, mostly with respect to dominant hemisphere involvement, among others. Less well established data such as awakening seizures in TLE patients, lateralization value of facial wiping (ipsilateral to the focus), statistically significant associations between behavioral pairs (dyads), and new behavioral sequences in TLE were also observed. We suggest that neuroethology also has great potential in the study of human epilepsy semiology. This work had an important role in method standardization for human epilepsy, setting the basis for the development of future clinical studies including correlation with other diagnostic methods (EEG, magnetic resonance, and SPECT). The next step will be the comparative study of seizures of patients with left and right TLE, with a greater number of patients, and the development of a digital video library.

Epilepsy in Colombia: Epidemiologic Profile and Classification of Epileptic Seizures and Syndromes

PURPOSE

A national study was performed in Colombia to determine the general and regional prevalence of epilepsy, clinical profiles, seizure types, and clinical syndromes.

METHODS

Based on the National Epidemiological Study of Neurological Diseases (EPINEURO), we evaluated and followed up for 1 year all the subjects with epilepsy from the National Sample. Clinical profiles were further assessed. Seizure types and epilepsy syndromes were established according to the international classifications.

RESULTS

General prevalence was found to be 11.3 per 1,000, with little variation among regions, except the eastern region, where prevalence was 23 per 1,000; prevalence for active epilepsy was 10.1 per 1,000. Women have a slightly greater (not statistically significant) risk. Most seizures are focal (partial), frequently with secondary generalization. The most frequent epilepsy syndrome encountered was partial symptomatic/cryptogenic (80%). Epilepsy onset in Colombia occurs most frequently in childhood.

CONCLUSIONS

Prevalence rates of epilepsy in Colombia are similar to those reported in nations with comparable developmental status and have diminished over time. The study presents the distribution of seizures and syndromes. The most frequent types are focal syndromes.

Investigation of social and emotion information processing in temporal lobe epilepsy with ictal fear

This study examined whether patients with temporal lobe epilepsy (TLE) and ictal fear (IF) show emotion recognition deficits similar to those associated with amygdala damage. Three groups of patients (13 with TLE and IF, 14 with TLE and nonfear auras (non-IF), and 10 with idiopathic generalized epilepsy (IGE)) completed tests of visual and face processing, face emotion recognition and social judgment, together with measures of psychological adjustment (Hospital Anxiety and Depression Scale; SCL-90-R) and Quality of Life (QOLIE-31). All three epilepsy groups had fear recognition deficits, with relatively greater impairments in the IF group. Fear recognition deficits were associated with impaired social judgment of trustworthiness, duration of epilepsy, and a measure of quality of life. Social cognition impairments previously associated with amygdala dysfunction are also a feature of the neuropsychology of TLE, and extend the hypothesis in that they may additionally play a role in IGE.

Focal semiologic and electroencephalographic features in patients with juvenile myoclonic epilepsy

PURPOSE

A few reports have described focal electroencephalographic or clinical features or both of juvenile myoclonic epilepsy (JME), but without video-EEG documentation. We examined focal clinical and EEG features in patients with JME who underwent video-EEG monitoring.

METHODS

Twenty-six patients (nine males and 17 females) who had seizures recorded during video-EEG monitoring were included. Age at seizure onset was 0 to 22 years (mean, 12.3 years), and age at monitoring was 12 to 44 years (mean, 26.5 years). In one patient with left parietooccipital epilepsy, primary generalized tonic-clonic seizures developed after resection of the parietal tumor. Two patients had both temporal lobe epilepsy and JME. Videotaped seizures in each patient were analyzed. Interictal and ictal EEG also were analyzed for any focal features.

RESULTS

Focal semiologic features were observed in 12 (46%) of 26 patients. Six patients had focal myoclonic seizures, and two had Figure 4 sign: one with version to the left, and another had left version followed by Figure 4 sign, and left arm clonic seizure. Their ictal EEGs were generalized at onset but with a lateralized evolution over the right hemisphere. The patient who had both JME and left parietooccipital epilepsy, right arm clonic seizure, and Figure 4 sign was seen during a generalized EEG seizure. Interictally, one patient had temporal sharp waves, and another had run of spikes in the right frontal region.

CONCLUSIONS

Fourteen (54%) of 26 patients with JME exhibited focal semiologic or electroencephalographic features or both. Video-EEG was essential in reaching a correct diagnosis and choosing an appropriate antiepileptic drug regimen.

Canine epilepsy: what can we learn from human seizure disorders?

Epilepsy is a common neurological disorder in both dogs and humans. It is refractory to therapy in approximately one-third of canine patients, and even with the advent of new antiepileptic drugs for humans, appropriate treatment options in dogs remain limited. The pathogenesis and pathophysiology of epilepsy is being studied extensively in both human patients and rodent models of experimental epilepsy at the cellular and molecular level, but very little is known about the aetiologies of epilepsies in dogs. In this review, canine epilepsy will be discussed with reference to the human epilepsies and experimental epilepsy research. There is much work to be done in order to classify canine seizure types and breed-specific epileptic syndromes, particularly with reference to electroencephalographic abnormalities and possible genetic abnormalities. The review considers the appropriate use of antiepileptic drugs: phenobarbitone and potassium bromide are effective in most canine patients, although dosing regimes need to be carefully tailored to the individual, with serum concentration measurement. However, a significant proportion of patients remains refractory to these drugs. Work is currently underway to test the efficacy of newer antiepileptic drugs in the treatment of canine epilepsy, and preliminary data suggest that human drugs such as levetiracetam and gabapentin are of benefit in dogs with refractory epilepsy.

Frontal lobe seizures

Despite the fact that clinical characteristics of frontal lobe seizures have been recently described better, differentiating seizures of frontal lobe origin from NES on clinical grounds alone is difficult. The difficulty has been compounded by the fact that both inter-ictal and ictal EEG can be normal or nonspecific, and the same is true of imaging studies. A detailed clinical history as well as video monitoring can be helpful diagnostic tools. A multidisciplinary approach is warranted and is at times essential to improve the diagnosis and care of these difficult patients.

Consciousness, epilepsy, and emotional qualia

The last decade has seen a renaissance of consciousness studies, witnessed by the growing number of scientific investigations on this topic. The concept of consciousness is central in epileptology, despite the methodological difficulties concerning its application to the multifaced ictal phenomenology. The authors provide an up-to-date review of the neurological literature on the relationship between epilepsy and consciousness and propose a bidimensional model (level vs contents of consciousness) for the description of seizure-induced alterations of conscious states, according to the findings of recent neuroimaging studies. The neurophysiological correlates of ictal loss and impairment of consciousness are also reviewed. Special attention is paid to the subjective experiential states associated with medial temporal lobe epilepsy. Such ictal phenomenal experiences are suggested as a paradigm for a neuroscientific approach to the apparently elusive philosophical concept of qualia. Epilepsy is confirmed to represent a privileged window over basic neurobiological mechanisms of consciousness.

Predictive clinical factors for the differential diagnosis of childhood extratemporal seizures

PURPOSE

To describe predictive clinical factors for the differentiation between childhood frontal lobe epilepsy (FLE) and posterior cortex epilepsy (PCE).

METHODS

Two independent, blinded investigators analyzed 177 seizures from 35 children (aged 11 months to 12 years) with extratemporal epilepsy selected by postoperative seizure-free outcome. Semiologic seizure components and different periictal signs were observed. Age at onset, auras, seizure frequency, and nocturnal dominance, as well as surgical and histopathologic data, were collected from medical charts.

RESULTS

Twenty patients had FLE, and 15 had PCE. Patients from both groups had daily seizures without significant differences in frequency but with higher nocturnal dominance in children with FLE (p < 0.05). Visual aura, nystagmus, and versive seizure were observed exclusively in the PCE group, whereas somatosensory aura and hypermotor seizures appeared only in FLE. Tonic seizures were significantly more frequent in FLE (p < 0.01), whereas the presence of clonic seizure (FLE; p = 0.07) and postictal nose-wiping (PCE; p = 0.05) showed only a trend to localize the seizure-onset zone. Myoclonic seizures, epileptic spasms, psychomotor seizures, atonic seizures, oral and manual automatisms, as well as vocalization and eye deviation appeared in both groups without significant differences in their frequency.

CONCLUSIONS

Characteristic features described in adults' extratemporal epilepsies were frequently missing during childhood seizures, especially in infants and preschool children. Ictal features help only a little in differentiating childhood FLE from PCE. Nocturnal appearance and the type of aura have high localizing value; therefore an accurate history taking is still an essential element of pediatric presurgical evaluation.

Time course and mapping of cerebral perfusion during amygdala secondarily generalized seizures

PURPOSE

Measurement of local cerebral blood flow (LCBF) is routinely used to locate the areas involved in generation and spread of seizures in epilepsy patients. Because the spatial distribution and extent of ictal CBF depends on the epileptogenic network, but also on the timing of injection of tracer, we used a rat model of amygdala-kindled seizures to follow the time-dependent changes in the distribution of LCBF changes.

METHODS

Rats were implanted in the left amygdala and were fully kindled. LCBF was measured by the quantitative [(14)C]iodoantipyrine autoradiographic technique bilaterally in 35 regions. The tracer was injected at 30 s before seizure induction (early ictal), simultaneous with the application of stimulation (ictal), at 60 s after stimulation (late ictal), at the end of the electrical afterdischarge (early postictal), and at 6 min after the stimulation (late postictal).

RESULTS

Rates of LCBF increased over control levels during the early ictal phase ipsilaterally in medial amygdala, frontal cortex, and ventromedian thalamus and bilaterally in the whole hippocampus, thalamic nuclei, and basal ganglia. During the ictal phase, all regions underwent hyperperfusion (81-416% increases). By 60 s after stimulation, rates of LCBF returned to control levels in most brain areas, despite ongoing seizure activity. At later times, localized foci of hypoperfusion were observed in hippocampus bilaterally, with a slight predominance in CA1 on the side of origin of the seizures.

CONCLUSION

This study shows a rapid spread of activation from the stimulated amygdala bilaterally to numerous limbic, cortical, and subcortical structures. The largest hyperperfusion was recorded during the ictal period with tracer injections simultaneous with the stimulation. The unilateral site of origin of seizures led to minor asymmetrical and lateralized findings, merely at early ictal and late postictal times, whereas intermediate tracer injections induced bilateral changes. Only late postictal measurements allowed the identification of significant changes in focal structures: the hippocampus is known to play a critical role in the spread of limbic seizures.

Hyperorality in Epileptic Seizures: Periictal Incomplete Kluver-Bucy Syndrome

PURPOSE

To analyze systematically hyperorality associated with epileptic seizures and its relation to the localization of epileptic activity.

METHODS

To identify patients with periictal hyperorality, we reviewed video-recordings of 269 patients (aged 6-59 years) who had consecutively undergone presurgical evaluations including ictal video-EEG recordings and high-resolution magnetic resonance imaging (MRI) and had had epilepsy surgery because of intractable frontal (FLE) or temporal lobe epilepsy (TLE). Periictal hyperorality was defined if patients put or unambiguously intended to put nonfood items into their mouths during or after at least one of the reviewed seizures. For the further analysis, we included only patients with periictal hyperorality. We reviewed their medical records and reexamined their ictal video-EEG recordings.

RESULTS

We identified eight patients (six women) aged 8-59 years who had hyperorality during or after seizures. Seven patients had TLE, and one patient had frontal lobe epilepsy (FLE). Three of these patients underwent right-sided surgery, whereas five patients had surgery on the left. Three patients exhibited ictal and five showed postictal hyperorality. Interictal EEG suggested bilateral interictal epileptiform discharges (IEDs) in three patients; in two other patients, no IEDs were detected. Ictal EEG suggested bilateral involvement in six cases. Patients with unilateral epileptiform activity had left TLE.

CONCLUSIONS

Periictal hyperorality is a rare phenomenon occurring in 3% of the investigated epilepsy population. We suggest that periictal hyperorality is an ictal-postictal mental disturbance, an incomplete Klüver-Bucy syndrome. In most patients, bilateral seizure activity plays an important role in the pathomechanism, but it would appear that left-sided epileptic activity without contralateral involvement also can cause periictal hyperorality.

The potential value of three-dimensional accelerometry for detection of motor seizures in severe epilepsy

Seizure detection results based on the visual analysis of three-dimensional (3D) accelerometry (ACM) and video/EEG recordings are reported for 18 patients with severe epilepsy. They were monitored for 36 hours during which 897 seizures were detected. This was seven times higher than the number of seizures reported by nurses during the registration period. The results in this article demonstrate that 3D ACM is a valuable sensing method for seizure detection in this population. Four hundred twenty-eight (48%) seizures were detected by ACM. With 3D ACM alone it was possible to detect all the seizures in 10 of the 18 patients. Three-dimensional ACM also was complementary to EEG in our population. ACM patterns during seizures were stereotypical in 95% of the motor seizures. These characteristic patterns are a starting point for automated seizure detection.

Genital automatisms in childhood partial seizures

PURPOSE

To describe frequency and electroclinical characteristics as well as localizing and lateralizing value of childhood periictal genital automatisms (GAs).

METHODS

Five-hundred-forty-one videotaped seizures of 109 consecutive patients <12 years with refractory partial epilepsy and postoperatively seizure-free outcome were analyzed. Genital automatisms (scratching, fondling or grabbing of the genitals) were monitored by two independent investigators.

RESULTS

Eight (four temporal, four extratemporal) patients (7%) showed GA at least once during 20 (3.7%) seizures. Age of patients with GA was between 4.5 and 11.9 (mean 9.5+/-2.4) years and was significantly higher than the age of children without GA (p=0.006). Boys showed GAs more frequently than girls (p=0.026). Genital automatisms appeared both ictally and postictally with a mean duration of 51s. They were unilateral (completed by one hand) in 18/20 seizures and were done by the hand ipsilateral to the seizure onset zone in 16/18 cases (p=0.001). Although consciousness was preserved during GA in 3/8 patients, neither periictal urinary urge nor penile erection was associated with it.

CONCLUSIONS

Periictal GAs appear in school-age patients with a similar frequency to that in adults but almost lack in preschool children. Although the presence of childhood GA has neither localizing nor lateralizing value per se, the hand used for GA is more frequently ipsilateral to the seizure onset zone. The mechanisms for childhood GAs are not clear but probably different from those of adults.

Occipital lobe epilepsy: clinical characteristics, surgical outcome, and role of diagnostic modalities

PURPOSE

To assess the role of various diagnostic modalities, to identify surgical prognostic factors and concordances with presurgical evaluations, and to characterize the clinical features of occipital lobe epilepsy (OLE), we studied 26 patients who were diagnosed as having OLE and underwent epilepsy surgery.

METHODS

Diagnoses were established by standard presurgical evaluations, which included magnetic resonance imaging (MRI), fluorodeoxyglucose-positron emission tomography (FDG-PET), ictal single-photon emission computed tomography (SPECT), scalp video-EEG monitoring, and intracranial EEG monitoring. After epilepsy surgery, patients were followed up for >2 years.

RESULTS

Sixteen (61.5%) of the 26 became seizure free after surgery, and another eight patients had a favorable outcome. Sixteen of the 26 patients experienced a type of visual aura (i.e., visual hallucination, visual illusion, blindness, or a field defect). Nine patients had both automotor seizures and secondary generalized tonic-clonic seizures at different times. Interictal EEG showed correctly localizing spikes in 10 of the 16 patients who became seizure free, and in three of the 10 non-seizure-free patients. MRI correctly localized the lesion in seven of these 16 seizure-free patients, and in three of the 10 non-seizure-free patients. FDG-PET correctly localized the lesion in eight of the 16 seizure-free patients, and in three of nine non-seizure-free patients. Ictal SPECT was performed in 19 patients and correctly localized the lesion in only three of 12 seizure-free patients, and in four of seven non-seizure-free patients. Ictal EEG correctly localized the lesion in 13 of the 16 seizure-free patients, and in five of the 10 non-seizure-free patients. No significant relation was found between the diagnostic accuracy of any modality and surgical outcome. The localizations of epileptogenic zones by these different diagnostic methods were complementary. The concordance of three or more modalities was significantly observed in seizure-free patients (p = 0.042). However, no definite relation was observed between the presence of lateralizing clinical seizure manifestation and surgical outcome (p = 0.108).

CONCLUSIONS

Some specific auras indicated an occipital epilepsy onset. Various diagnostic methods can be useful to diagnose OLE, and a greater concordance between presurgical evaluation modalities indicates a better surgical outcome.

Comparison of classifications of seizures: a preliminary study with 28 participants and 48 seizures

PURPOSE

Our aim was to compare three available seizure classifications (SCs), namely, the international classification of epileptic seizures published in 1981 (ICES; Epilepsia 1981;22:489-50); the semiological seizure classification (SSC) by H. Luders, J. Acharya, C. Baumgartner, et al. (Epilepsia 1998;39:1006-13; Acta Neurol Scand 1999;99:137-41); and the proposal of a new diagnostic scheme for seizures (PDSS) by J. Engel, Jr. (Epilepsia 2001;42:796-803) published in 2001. The three SCs were compared with respect to diagnostic success rates, usefulness, and consistency by a large group of neurologists in this preliminary study.

METHODS

After a training period, 28 blindfed participants with different levels of experience with epilepsy classified videos or written descriptions of 48 randomly selected seizures according to the three SCs. Definite diagnoses of the seizures were established based on all clinical, ictal/interictal EEG, and MRI data. All the participants answered a questionnaire concerning their preferences for SCs after the study.

RESULTS

The overall diagnostic success rates were 81.4% for ICES, 80.5% for PDSS, and 87.5%, for SSC. Various parameters concerning experience with epilepsy affected success rates positively, without reaching statistical significance, whereas experience with epilepsy surgery appeared to be a parameter significantly affecting the success rate in all SCs. In reliability analysis, Cronbach's alpha was 0.94 for ICES, 0.88 for PDSS, and 0.70 for SSC, all showing good agreement in the group. Nineteen reviewers chose SSC, eight chose ICES, and one chose PDSS as their preference in the questionnaire, completed after the end of the study.

CONCLUSION

The results of this preliminary study demonstrate that with proper training, physicians treating epilepsy patients can handle new SCs, and emphasize the need for revision of the current classification.

Presurgical evaluation and cognitive functional reorganization in Fishman syndrome

Fishman syndrome, also known as encephalocraniocutaneous lipomatosis (ECCL), is a rare, congenital neurocutaneous syndrome characterized by unilateral skin, eye, and brain abnormalities. Epileptic seizures and developmental delay are usually present. We report the clinical, radiological, and, for the first time, neurophysiological findings in a 24-year-old woman diagnosed with ECCL who was evaluated for epilepsy surgery. Functional magnetic resonance imaging revealed transfer of memory and language functions to the nonaffected hemisphere, providing evidence that functional reorganization and restoration of cognitive functions may occur in the context of extensive malformations, such as neurocutaneous syndromes.

Ictal Smile Lateralizes to the Right Hemisphere in Childhood Epilepsy

PURPOSE

To analyze the localizing and lateralizing value of ictal smile (IS) in childhood epilepsy.

METHODS

Incidence of IS in 309 videotaped seizures of 114 consecutive patients younger than 12 years with refractory frontal, temporal, or posterior cortex epilepsy were assessed.

RESULTS

Among patients with right-sided epileptogenic zone, 12 (21%) of 57 had IS, whereas in patients with left-sided epilepsy, IS occurred only in one patient (1.8%; p < 0.01, chi(2) test). The incidence of IS was 11%, 3%, and 26% in the frontal, temporal, and posterior cortex subgroups, respectively. Logistic regression revealed that the localization of the epileptogenic region in the posterior cortex (p < 0.01), focal cortical dysplasia etiology (p = 0.012), and right-sided lateralization (p = 0.025) were independently associated with the presence of IS.

CONCLUSIONS

Childhood IS lateralizes to the right hemisphere and localizes more frequently in the posterior cortex epilepsy.

Autonomic seizures in 18q- syndrome

The 18q- syndrome is due to (terminal) deletion in the long arm of chromosome 18 with variable break points. The phenotype is also variable, with a variety of dysmorphisms, neurological deficits possibly related to haploinsufficiency of the gene for myelin basic protein, and frequent cardiac problems. The diagnosis of paroxysmal events in 18q- syndrome presents difficulties because both epileptic seizures and cardiac syncopes might be expected to occur. Autonomic seizures are epileptic seizures consisting of episodic alterations of autonomic function that are elicited by activation of autonomic cortical centres. In such events confusion with syncope is even more likely. A previous case of autonomic seizures masquerading as syncope in an adult has been reported. The present report is the first to describe autonomic seizures in 18q- syndrome in a child. Very frequent episodes of prolonged apnoea with profound oxygen desaturation was associated with a focal EEG discharge, arising from either the right temporal or left temporal region. As in the adult patient referred to, the seizures ceased on carbamazepine. No systematic studies of incidence have been published, but autonomic epileptic seizures simulating non-epileptic syncopes may be a feature of 18q- syndrome.

Symptoms in focal sensory seizures

PURPOSE

Aura is a brief subjective symptom that may represent the initial manifestation of a partial epileptic seizure with objective signs or constitute the entire epileptic attack (focal sensory seizure (FSS)). We studied the electro-clinical features of FSSs recorded in 28 patients.

METHODS

Using long-term surface video-EEG recordings, we examined 28 patients (from a consecutive series of 64) with stereotyped FSSs and complex partial seizures (CPS) preceded in at least one instance by identical subjective manifestations (overall 255 FSSs and 39 CPS were recorded). FSSs were subdivided according to the type of sensation into somatosensory, visual or oculosensory, viscerosensory, experiential, cephalic and diffuse warm sensations. The EEG discharges accompanying FSSs were examined by two of the authors either blinded as to the type and timing of the seizure, or unblinded, i.e. after receiving complete clinical information including timing of the patient's warning.

RESULTS

The ictal pattern accompanying FSSs was identified blind in 13 patients and unblind in 8 patients. In seven patients, the ictal discharge remained undetected. In the cases with recognizable ictal abnormalities, two main patterns could be distinguished, static and dynamic. FSSs whose ictal discharge could be recognized by blind EEG examination more frequently consisted of somatosensory and visual or oculosensory manifestations, and the discharge generally involved the centro-parieto-occipital regions. The ictal discharge of viscerosensory and experiential FSSs more easily remained undetected; when identified, it generally involved the fronto-temporal regions.

CONCLUSIONS

FSSs are often accompanied by ictal abnormalities recognizable on surface EEG. A thorough knowledge of their EEG accompaniments may be a useful diagnostic aid in patients with partial epilepsy.

Localising and lateralising value of ictal piloerection

BACKGROUND

Piloerection is a rare clinical symptom described during seizures. Previous reports suggested that the temporal lobe is the ictal onset zone in many of these cases. One case series concluded that there is a predominant left hemispheric representation of ictal cold. The aim of this study is to evaluate the localising and lateralising value of pilomotor seizures.

METHODS

Medical records of patients who underwent video electroencephalogram (EEG) monitoring at the Cleveland Clinic between 1994 and 2001 were reviewed for the presence of ictal piloerection. The clinical history, physical and neurological examination, video EEG data, neuroimaging data, cortical stimulation results, and postoperative follow ups were reviewed and used to define the epileptogenic zone. Additionally, all previously reported cases of ictal piloerection were reviewed.

RESULTS

Fourteen patients with ictal piloerection were identified (0.4%). Twelve out of 14 patients had temporal lobe epilepsy. In seven patients (50%), the ictal onset was located in the left hemisphere. Four out of five patients with unilateral ictal piloerection had ipsilateral temporal lobe epilepsy as compared with the ipsilateral side of pilomotor response. Three patients became seizure free after left temporal lobectomy for at least 12 months of follow up. An ipsilateral left leg pilomotor response with simultaneously recorded after-discharges was elicited in one patient during direct cortical stimulation of the left parahippocampal gyrus.

CONCLUSIONS

Ictal piloerection is a rare ictal manifestation that occurs predominantly in patients with temporal lobe epilepsy. Unilateral piloerection is most frequently associated with ipsilateral focal epilepsy. No hemispheric predominance was found in patients with bilateral ictal piloerection.

Parietal Lobe Epilepsy: The Semiology, Yield of Diagnostic Workup, and Surgical Outcome

PURPOSE

To characterize the clinical features, the prognostic value, and diagnostic sensitivities of various presurgical evaluations and the surgical outcomes in parietal lobe epilepsy (PLE), we describe 40 patients who were diagnosed as having PLE, including 27 surgically treated patients.

METHODS

The diagnosis was established by means of a standard presurgical evaluation, including magnetic resonance imaging (MRI), fluorodeoxyglucose-positron emission tomography (FDG-PET), ictal single-photon emission tomography (SPECT), and scalp video-electroencephalography (EEG) monitoring, with additional intracranial EEG monitoring in selected cases.

RESULTS

Among the 40 patients, 27 experienced at least one type of aura. The most common auras were somatosensory (13 patients), followed by affective, vertiginous, and visual auras. The patients had diverse manifestations. Eighteen patients showed simple motor seizure, followed by automotor seizure, and dialeptic seizure. Two patients manifested generalized tonic-clonic seizures only, and 19 patients experienced more than one type of seizure. The surgical outcome was favorable in 22 of 26 patients including 14 who were seizure free. Patients with localized MRI abnormality had a higher probability to be seizure free, with marginal significance (p = 0.062), whereas other diagnostic modalities failed to predict the surgical outcome. In the seizure-free group, localization sensitivity was 64.3% by MRI, 50% by PET, 45.5% by ictal SPECT, and 35.7% by ictal EEG. The concordance rate of the various diagnostic modalities was higher in the seizure-free group than in the non-seizure-free group, although it did not reach statistical significance.

CONCLUSIONS

Seizures, in the case of PLE, can manifest themselves in a wider variety of ways than was previously thought. Surgical outcome was favorable in most of the patients. MRI abnormality and concordance of different diagnostic modalities were associated with high seizure-free rate.

Status epilepticus and seizures induced by iopamidol myelography

PURPOSE

To report that iopamidol myelography can induce status epilepticus (SE) in patients carrying the diagnosis of symptomatic epilepsy and to estimate the incidence of seizures in patients undergoing iopamidol myelography.

METHODS

We retrospectively identified all patients with seizures/SE associated with 1350 iopamidol myelographies during the last 5 years at our institution. The impact of cervical versus lumbar myelography was analysed.

RESULTS

Induced by iopamidol myelography two non-epileptic patients suffered from first generalised tonic-clonic seizures and a 67-year-old women with symptomatic epilepsy after a remote ischemic stroke developed a generalised tonic-clonic seizure evolving into a dialeptic and right nystagmus SE (i.e. complex focal status) of 5-hour duration. The incidence of seizures in non-epileptic patients was 0.15%. The incidence of seizure induction for lumbar myelography was lower than for myelographies that included the cervical subarachnoid space.

CONCLUSIONS

Iopamidol myelography (especially if cervical) is associated with a risk of seizures in non-epileptic individuals and can induce SE in patients with epilepsy. Patients should be informed about the risk of seizure induction.

Specific Epileptic Syndromes Are Rare Even in Tertiary Epilepsy Centers: A Patient‐oriented Approach to Epilepsy Classification

PURPOSE

To assess the practicability and reliability of a five-dimensional patient-oriented epilepsy classification and to compare it with the International League Against Epilepsy (ILAE) classification of epilepsy and epileptic syndromes. The dimensions consist of the epileptogenic zone, semiologic seizure type(s), etiology, related medical conditions, and seizure frequency.

METHODS

The 185 epilepsy patients (94 adults, 91 children, aged 18 years or younger) were randomly selected from the database of a tertiary epilepsy center and the general neurological department of a metropolitan hospital (28 adults). The charts were reviewed independently by two investigators and classified according to both the ILAE and the patient-oriented classification. Interrater reliability was assessed, and a final consensus among all investigators was established.

RESULTS

Only four (4%) adults and 19 (21%) children were diagnosed with a specific epilepsy syndrome of the ILAE classification. All other patients were in unspecific categories. The patient-oriented classification revealed that 64 adults and 56 children had focal epilepsy. In an additional 34 adults and 45 children, the epileptogenic zone could be localized to a certain brain region, and in 14 adults and five children, the epileptogenic zone could be lateralized. Fourteen adults and 21 children had generalized epilepsy. In 16 adults and 14 children, it remained unclear whether the epilepsy was focal or generalized. Generalized simple motor seizures were found in 66 adults and 52 children, representing the most frequent seizure type. Etiology could be determined in 40 adults and 45 children. Hippocampal sclerosis was the most frequent etiology in adults (10%), and cortical dysplasia (9%), in children. Seven adults and 31 children had at least daily seizures. Seventeen adults and 26 children had rare or no seizures at their last documented contact. The most frequent related medical conditions were psychiatric disorders and mental retardation. Interrater agreement was high (kappa values of 0.8 to 0.9) for both the patient-oriented and the ILAE classification.

CONCLUSIONS

Specific epilepsy syndromes included in the current ILAE classification are rare even in a tertiary epilepsy center. Most patients are included in unspecific categories that provide only incomplete information. In contrast, all of the patients could be classified by the five-dimensional patient-oriented classification, providing all essential information for the management of the patients with a high degree of interrater reliability.