Non-convulsive status epilepticus associated with tiagabine therapy in children

A case of a 7-year-old male with epilepsy who developed non-convulsive status epilepticus (NCSE) with electroclinical features consistent with those of atypical absence seizures after adjunctive antiepileptic therapy of tiagabine (TGB) is reported. The patient had frequent generalised and rare partial seizures with generalised epileptic discharges on prior electroencephalogram (EEG) recordings. NCSE was developed when rapid dosage increase and high dose of TGB was given. This case emphasises the need for close monitoring of children with epilepsy taking TGB for exacerbation of seizures or development of NCSE.     

Oxcarbazepine and atypical evolution of benign idiopathic focal epilepsy of childhood

Patients that have benign epilepsy with centrotemporal spikes (BECTS) may occasionally experience an atypical development in their course when treated with drugs such as carbamazepine. Three patients with electroclinical patterns consistent with BECTS showed seizure exacerbation during oxacarbazepine (OXC) therapy. Two manifested atypical absences, neuropsychological disturbances, and generalized spike-and-wave discharges in their electroencephalograms (EEGs) that became continuous during sleep. The third patient showed, during OXC therapy, more frequent partial motor seizures which ended with ictal vomiting and post-ictal obnubilation. EEGs recorded during sleep showed discontinuous paroxysmal activity in the right centrotemporal area. Symptoms were reversed following discontinuation of the OXC therapy. Although electroclinical findings were consistent with a BECTS diagnosis, all patients had some atypical features. Our observations show that BECTS patients, in particular those presenting with atypical findings, might be at risk for developing paradoxical reactions to OXC therapy. We suggest that OXC should be included in the list of drugs that may cause electroclinical deterioration in these patients.     

Tiagabine-induced generalised non convulsive status epilepticus in patients with lesional focal epilepsy.

PURPOSE: To report 3 cases with focal lesional epilepsy that had non-convulsive status epilepticus (NCSE) induced by treatment with tiagabine (TGB) and review the previously published cases. Drugs that enhance GABAnergic transmission are recognised to promote absence seizures in patients with generalised epilepsy syndromes and may on occasions even induce NCSE. However, that TGB can also induce NCSE in focal lesional epilepsy is not widely recognised in clinical practice. METHOD: The clinical history, EEG and MRI findings were reviewed in 3 patients with lesional focal epilepsy who presented to our epilepsy programs over a 12 month period with TGB-induced NCSE. All previously reported cases in the English medical literature were reviewed. RESULTS: The three patients had longstanding complex partial and secondarily generalised seizures refractory to multiple different anti-epileptic drugs. In two cases, MRI demonstrated a focal malformation of cortical development in the left parieto-occipital region and in the third left mesial temporal sclerosis. Following commencement of TGB in one patient and dose escalation in two, prolonged episodes of confusion and poor responsiveness were noted. Prolonged EEG monitoring demonstrated continuous high amplitude, generalised, 2-4 Hz delta activity with intermingled spikes during the episodes of unresponsiveness, consistent with NCSE. The clinical and EEG activity normalised following the administration of IV clonazepam followed by dose reduction or withdrawal of the TGB. Eleven previously reported cases of patients with partial epilepsy and a focal underlying lesion on MRI were identified, all of whom had similar features to that seen in our cases. CONCLUSIONS: These cases illustrate that TGB may induce generalised NCSE in patients with focal lesional epilepsy, in addition to those with generalised syndromes. We hypothesise that patients may have developed an acquired alteration in the sensitivity of their thalamocortical circuitry that renders them more sensitive to the effects of drugs that enhance GABAnergic activity.     

Clinical and neurophysiologic spectrum associated with atypical absence seizures in children with intractable epilepsy

The aim of this study was to describe the clinical and neurophysiologic correlates of atypical absence seizures in children with intractable epilepsy. In a retrospective review, 19 children with videoelectroencephalographic monitoring (female n=14; male n=5) fulfilled the electroclinical criteria for this seizure type. Atypical absence seizures occurred in a spectrum of clinical conditions associated with educational disability and intractable seizures. In comparison with children with only atypical absence seizures, children with atypical absence in association with multiple seizure types were more likely to have severe educational disability (n=11 of 13; P = .01), a slower ictal frequency (n=10 of 13; P = .01), and slow background rhythms for age (n = 13 of 13; P = .03). This study illustrates the broad clinical spectrum in which atypical absence seizures are encountered. Differentiation between children with only atypical absence seizures and children with multiple seizure types can be useful with respect to potential academic ability.     

Non-convulsive status epilepticus associated with tiagabine in a pediatric patient

We report a 4-year-old patient who developed non-convulsive status epilepticus (NCSE) following tiagabine (TGB) as add-on treatment for refractory partial seizures. NCSE occurred while the patient received TGB 0.83 mg/kg/day. In our case, the TGB reduction led to a significant improvement of electroclinical features. The mechanisms of this abnormal effect are not clear. GABA-ergic hyperfunction and/or multiplicity of interlinked brain GABA systems associated with individual specific sensitivity could play a critical role in the pathogenesis of NCSE. This is the first report of NCSE documented by electroencephalogram (EEG) in a child under 12 years of age on TGB treatment.     

Nonconvulsive Status Epilepticus in Childhood Localization-Related Epilepsy

PURPOSE: To report on three children with localization-related epilepsy who exhibited minor seizures (atypical absences, brief atonic, and myoclonic) and nonconvulsive status epilepticus (NCSE) consisting of these minor seizures, and to elucidate their significance. METHODS: We studied the electroclinical characteristics of these children. Ictal electroencephalograms (EEGs) of NCSE were evaluated by using simultaneous video-EEG-electromyogram (EMG) polygraphic recordings. RESULTS: All patients began to have partial seizures between the ages of 6 months and 2 years 7 months, with minor seizures appearing later, between the ages of 1 year 11 months and 6 years 6 months. These minor seizures evolved into NCSE. Complex partial seizures remained after suppression of the minor seizures. Interictal EEGs taken when the minor seizures appeared showed excessive diffuse epileptic discharges in addition to multifocal spike-waves. Before and after suppression of the minor seizures, focal epileptic discharges predominated on the EEGs. On ictal EEGs of brief atonic and myoclonic seizures, diffuse spike-wave and polyspike-wave bursts were detected. Ictal EEGs of the atypical absences revealed diffuse spike-wave bursts mixed with irregular high-voltage slow waves, often interspersed with brief atonic and myoclonic seizures. When atypical absences lasted for a long time, patients manifested NCSE. Polytherapy might be related to the occurrence of minor seizures and NCSE, because all patients were treated with polytherapy at their appearance, and simplification of antiepileptic drug (AED) therapy seemed to be effective. CONCLUSIONS: We concluded that this NCSE is a type of atypical absence status which is an age-dependent, transient, electroclinical condition. The mechanism of occurrence of these minor seizures might be related to secondary bilateral synchrony.     

Two Cases of Nonconvulsive Status Epilepticus in Association with Tiagabine Therapy

We report two patients with intractable partial seizures who developed generalized nonconvulsive status epilepticus (NCSE) after receiving tiagabine (TGB). Neither had a history of absence seizures or generalized epileptic discharges on prior EEG monitoring. Clinicians need to be aware of a possible association between TGB and NCSE.     

Coexistence of temporal lobe and idiopathic generalized epilepsies.

OBJECTIVE: To assess the interrelation of idiopathic generalized epilepsy (IGE) and temporal lobe epilepsy (TLE) when they coexist in the same patient. METHODS: The authors reviewed the electroclinical features of 350 consecutive patients who had temporal resection between 1975 and 1997 at the Maudsley and King's College Hospitals, London. RESULTS: Two patients had the unusual combination of TLE and IGE (0.57%). In the first, the clinical onset of juvenile myoclonic epilepsy followed the surgical resolution of his partial seizures but had been heralded for at least 5 years by subclinical spontaneous and photically induced generalized spike-wave discharges. In the second, TLE and juvenile absence epilepsy had a long parallel course before surgery. After surgery he had no further partial seizures. CONCLUSION: These cases suggest that when an idiopathic absence or myoclonic syndrome manifests in a patient with symptomatic TLE, the phenotype may not be a merged syndrome. Rather, the two conditions can retain their inherent electroclinical profile, responsiveness to treatment, and prognosis.     

Unilateral closed-lip schizencephaly and epilepsy: a comparison with cases of unilateral polymicrogyria

We compared the electroclinical features and evolution of patients with two different types of abnormal cortical organization: unilateral closed-lip schizencephaly (SCHZ) and unilateral polymicrogyria (PMG). Between February 1990 and June 2002, 51 children with either unilateral PMG or closed-lip SCHZ were selected through neuroradiological analysis for investigation at our service. We evaluated the frequency of epilepsy, electroclinical features and evolution. The mean time of follow-up was 7 years (range 1-12 years). All patients underwent neurological examination, computed tomography scan and magnetic resonance imaging, serial electroencephalographic (EEG) recordings and neuropsychological assessment. Thirty-six of the 51 patients had unilateral PMG. All patients had hemiparesis with mild spasticity. Mental retardation was mild in 20 and moderate in 14. In two patients IQ was normal. Partial motor seizures were recorded in 28 patients, with secondary generalization in 20. The median age at onset of seizures was 2 years (range 4 months-7 years). Interictal EEGs showed unilateral spikes in all patients. In 21 patients epilepsy worsened between the ages of 4 and 8 (mean 5.6 years) with frequent atonic seizures, atypical absences, epileptic negative myoclonus and gait difficulties. EEGs showed continuous spike-wave activity or bilateral high-frequency spike discharges during slow-wave sleep. Frequent relapses of atonic and myoclonic seizures were seen in nine patients. At present, 16 patients are seizure-free. Fifteen patients with unilateral SCHZ were included in the study. Focal motor seizures were registered in seven cases, in three of them with secondary generalization. The median age at onset of epilepsy was 2.5 years (range 1-4 years). Interictal EEGs showed unilateral spikes in these seven cases. All patients except one presented mild spastic hemiparesis. Mental retardation was mild in ten children, moderate in two and IQ was normal in three. Although the underlying mechanisms leading to PMG and SCHZ are probably similar, the electroclinical phenomenon of secondary bilateral synchrony with frequent negative myoclonus was not present in our cases with unilateral closed-lip SCHZ.     

Tiagabine-induced absence status in idiopathic generalized epilepsy.

Several medications such as baclofen, amitriptyline and even antiepileptic drugs such as carbamazepine or vigabatrin are known to induce absence status epilepticus in patients with generalized epilepsies. Tiagabine (TGB) is effective in patients with focal epilepsies. However, TGB has also been reported to induce non-convulsive status epilepticus in several patients with focal epilepsies and in one patient with juvenile myoclonic epilepsy. In animal models of generalized epilepsy, TGB induces absence status with 3-5 Hz spike-wave complexes. We describe a 32-year-old patient with absence epilepsy and primary generalized tonic-clonic seizures since 11 years of age, who developed her first absence status epilepticus while treated with 45 mg of TGB daily. Administration of lorazepam and immediate reduction in TGB dosage was followed by complete clinical and electroencephalographic remission. This case demonstrates that TGB can induce typical absence status epilepticus in a patient with primary generalized epilepsy.     

Idiopathic generalized epilepsies with versive or circling seizures

OBJECTIVES: To describe the electroclinical features of the idiopathic generalized epilepsies (IGEs) with versive or circling seizures. METHODS: Sixteen patients with versive or circling seizures and interictal electroclinical features of IGE were studied. Patients with insufficient clinical or imaging data, with a follow-up period less than 1 year or with partial seizures in addition to the versive or circling ones were excluded from the study. All patients underwent full interictal clinical and neurophysiological studies. The EEG patterns of 13 versive or circling seizures from 4 patients were also analyzed. RESULTS: A specific IGE syndrome was recognized in 9 out of the 16 patients (56%). More specific, 1 patient had childhood absence epilepsy (CAE), 4 had juvenile absence epilepsy (JAE), and 4 had juvenile myoclonic epilepsy (JME). No specific IGE syndrome was recognizable in the remaining 7 patients (44%). These 7 patients had a juvenile epileptic syndrome (mean age at onset of seizures was 15.7 years) characterized by versive or circling seizures followed or not by generalized tonic-clonic fits. Three main EEG patterns were identified during versive or circling seizures: 1) generalized spike-and-wave discharges at 3-4 cps; 2) generalized polyspike-and-wave discharges at 1 to 2.5 cps beginning with generalized fast activity at 12-14 cps, and 3) generalized spike-and-wave discharges at 3-4 cps intermingled with fast activity at 12-14 cps. Most patients had good response to treatment on a single drug regimen (mainly valproic acid). CONCLUSIONS: Versive or circling seizures may occur in the context of an IGE. Although many individuals share the features of different IGE syndromes including CAE, JAE and JME, a consistent number of patients, who show circling or versive seizures solely, remain without a specific syndromic diagnosis. When occurring in the context of IGE, circling or versive seizures do not worsen the prognosis.     

Electroclinical Seizures in Lennox-Gastaut Syndrome

Summary: We analyzed electroclinical seizures observed by long video split-screen recording in 21 patients with Lennox-Gastaut syndrome (LGS). All patients had atypical absence seizures, 18 (81%) had tonic seizures, and 4 (21%) had myoclonic-atonic seizures. Tonic seizures were axial with flexion or extension of the head or trunk, or global with generalized tonic spasm mimicking infantile spasm, or involved the eyeballs only (either brief, with upward deviation of eyeballs or long, with oscillatory nystagmus). EEG showed either a bilateral 10–13-Hz rhythm or generalized synchronous spike wave at 3 Hz. Myoclonic-atonic seizures involving limbs, trunk, or neck were either brief or massive; the discharges were 2–3.5-Hz spike wave. Atypical absence seizures evolved gradually, terminated abruptly, and manifested alone or with subtle motor activity or oral automatism. EEG discharges were variable and of different types: (a) Diffuse irregular spike wave at 2–2.5 Hz with or without fragmentation (consciousness was regained during fragmentation or when spike wave discharges were >2 Hz), (b) irregular diffuse fast activity at 10–13 Hz, or (c) a combination of fast spike wave or sharp waves of increasing amplitude followed by synchronous spike wave discharges at 3 Hz.     

Contribution of magnetic resonance imaging in 100 cases of refractory partial epilepsy with normal CT scans

One hundred epileptic patients were included in this study according to the following criteria: intractable partial epilepsy, normal CT scan and focal EEG abnormalities. Eighty-nine patients were suffering from complex partial seizures of temporal or frontal origin, 55 and 34 cases respectively. Eleven patients presented with only simple partial seizures. MRI was abnormal in 31 patients. The abnormalities were: focal T2 increased signal intensity (13 cases) most often temporal (10 cases), cryptic arteriovenous malformation (4 cases), focal T1 and T2 signal abnormality (4 cases), focal atrophy (2 cases) and multiple abnormal T2 signals scattered in the white matter (8 cases). The site of MRI abnormalities was consistent with electroclinical data in 22 patients, of whom 20 had a temporal lobe epilepsy. Thus MRI proved to be more often abnormal in temporal than in frontal lobe epilepsy (36 p. 100 and 5.9 p. 100 respectively) when the CT scan is normal. However MRI data, particularly focal T2 hypersignals should be confronted to electroclinical and metabolic findings whenever functional surgery is considered.     

Electroclinical patterns and evolution of epilepsy in the 4p- syndrome

BACKGROUND: Wolf-Hirschhorn syndrome (WHS) is a well-known clinical entity caused by partial deletion of the short arm of one chromosome 4 (4p- syndrome). Seizures occur in almost all the cases, but studies on the electroclinical disorder and its evolution are still scarce. We present a longitudinal study of the electroclinical features in 10 children with WHS. METHODS: Ten patients (five boys and five girls) underwent a detailed clinical assessment and a prolonged EEG study. Six of the 10 also had video-polygraphy. RESULTS: Nine of the 10 patients had seizures; they were generalized or unilateral clonic and tonic-clonic, and atypical absences associated with myoclonic jerks. Age at onset of seizures varied from 1 day to 2.5 years. In all the patients, including the only one without seizures, two stereotyped EEG patterns were observed, consisting of (a) bursts of rhythmic (3-5 Hz), high-voltage slow waves located in the posterior regions and increased by sleep, or bursts of rapid spike-wave complexes in the centroparietal and parietooccipital regions; and (b) repetitive rapid posterior spikes. Sleep organization was constantly absent or very poor. The evolution of epilepsy was frequently good, with four seizure-free cases at the end of follow-up, two of them weaned from antiepileptic drugs (AEDs). CONCLUSIONS: Seizure onset in WHS also can occur at neonatal age. At least two electrical stereotyped patterns of the epileptic disorder are associated with a relevant disorganization of the sleep states. Prognosis of epilepsy is generally good both for the seizure control and for its evolution.     

Prognostic and electroclinical features of grand mal epilepsies

We studied the electroclinical features and prognosis of 103 patients with tonic-clonic seizures alone. Patients were classified into three groups according to seizure semiology and interictal EEG: primary grand mal, focal grand mal and indeterminate grand mal. Discriminant analysis showed that a number of other electroclinical features had no significant classificatory power. Patients have been followed for 2-10 years. At the last observation 40% of patients were free from tonic-clonic seizures and 23% had fewer than 1 seizure a year, without differences among the three groups. The appearance of 'minor' (absence or partial) seizures during follow-up occurred in 12 patients and did not change the prognosis of tonic-clonic seizures. At the end of follow-up, 96% of patients had a normal social adjustment. Grand mal epilepsies therefore appear to have a good prognosis.     

Idiopathic childhood occipital epilepsy of Gastaut: report of 12 patients

This study sought to present clinical and outcome data of patients with idiopathic childhood occipital epilepsy of Gastaut, to validate previously reported characteristics of this epilepsy. The study group was comprised of 12 affected children (three boys and nine girls), with a median age of onset at 10.3 years. Common ictal manifestations included elementary visual hallucinations (75.0%), blindness or blurring of vision (50.0%), headache (50.0%), and secondarily generalized tonic-clonic seizures (58.3%). Interictal electroencephalography revealed occipital spike-wave paroxysms reactive to eye closure and opening in all patients, accompanied by spike-wave activity in the extra-occipital areas in four (33.3%), and by generalized spike-wave discharges in two (16.7%). One patient exhibited the onset of occipital lobe seizures 1 year after manifesting absence epilepsy. Seizure remission occurred in 81.8% of cases, in half of which medication was discontinued by late adolescence. This study confirmed the previously delineated electroclinical features of epilepsy syndrome, with additional aspects including the frequent association of generalized tonic-clonic seizures and atypical evolution from childhood absence epilepsy.     

Periventricular Nodular Heterotopia: Epileptogenic Findings

Summary: Purpose : We studied 17 patients with periventricular nodular heterotopia (PNH) to further investigate the electroclinical pictures and semiology of the associated seizures.
Methods : PNH was diagnosed by means of magnetic resonance imaging (MRI). The patients' clinical and familial histories were carefully analyzed, and their electroclinical features and course of epilepsy followed for periods ranging from 10 months to 22 years. The electroclinical data were compared with those of previously reported PNH cases.
Results : The patients were subdivided into those with bilateral (7) and unilateral (10) PNH. The former were mainly characterized by structural abnormalities in the posterior cerebral fossa and multiple seizure types; the latter were characterized by the paratrigonal location of the malformation and, frequently, by elementary seizures with a visual or auditory onset. Focal seizures were drug resistant in most cases. The interictal EEG abnormalities were always focal and consistent with the location of the PNH. A previously unreported photic driving of posterior background activity was observed in all patients and was always consistent with the PNH location.
Conclusions : Conclusions: Our present findings and previously reported data show that bilateral and unilateral PNH cases are different in their morphological and electroclinical features and may be determined by different etiologies. The female predominance, frequent familial occurrence, and positive family history for epilepsy suggest that genetic factors may be involved in the genesis of bilateral and symmetrical PNH, whereas the presence of prenatal risk factors and its location in the watershed paratrigonal area suggest that vascular mechanisms may determine unilateral PNH.     

Epilepsy With Myoclonic Atonic Seizures: An Electroclinical Study of 69 Patients

Epilepsy with myoclonic-atonic seizures is characterized by myoclonic-atonic, absence, tonic-clonic, and eventually tonic seizures, appearing in previously normal children at ages 18-60 months. We analyzed the electroclinical features, treatment, and outcome of 69 patients with myoclonic-atonic seizures; these patients were followed between 1990 and 2012 at the Juan P. Garrahan Pediatric Hospital, Buenos Aires, Argentina. No structural or metabolic etiology was identified. Based on the electroclinical features and evolution, two groups could be distinguished. The first group of 39 patients with myoclonic and myoclonic-atonic seizures with or without generalized tonic-clonic seizures and absences associated with generalized spike- and polyspike-and-wave paroxysms had excellent prognoses. The second group of 30 patients had myoclonic jerks and myoclonic-atonic seizures associated with other seizure types including tonic seizures; some had myoclonic status epilepticus and cognitive deterioration. The interictal EEG showed frequent generalized spike- and polyspike-and-wave paroxysms. In 16 patients, the seizures remitted within 3.6 years. The two groups were distinguished in retrospect, when enough time had elapsed to evaluate cognitive deterioration and different seizure types. In conclusion, epilepsy with myoclonic atonic seizures is an epileptic syndrome with a broad clinical spectrum and variable prognosis.     

Is phenotype difference in severe myoclonic epilepsy in infancy related to SCN1A mutations?

We classified 28 patients with severe myoclonic epilepsy in infancy (SME) according to the presence or absence of myoclonic seizures and/or atypical absences. Eleven of the patients had myoclonic seizures and/or atypical absences, and we refer to this condition as 'typical SME (TSME)'. Seventeen of the patients had only segmental myoclonias, and we refer to this condition as 'borderline SME (BSME)'. We then analyzed the electroclinical and genetic characteristics of these two groups. Ten of the 11 TSME patients had a photoparoxysmal response at some time during their clinical course, while none of the BSME patients showed this response. TSME and BSME showed a significant difference in regard to gender ratio: female dominance in TSME and male dominance in BSME (P=0.008). The detection rate of the voltage-gated sodium channel alpha1-subunit (SCN1A) gene mutations was 72.7 and 88.2% in TSME and BSME, respectively. There was no difference in the type or rate of mutation between TSME and BSME. We conclude that TSME and BSME show distinct differences in photoparoxysmal response and gender, which might be caused by some genetic mechanism(s) other than the SCN1A gene mutation.     

Migrating focal seizures in infancy: analysis of the electroclinical patterns in 17 patients

We describe the electroclinical features, therapy, and long-term evolution of 17 patients with migrating focal seizures in infancy, and analyzed the charts of these patients seen between February 1985 and July 2005. Three different electroclinical patterns were recognized: (1) 8 cases with alternating simple focal motor seizures at onset. The ictal electroencephalography (EEG) pattern was characterized by recurrence of rhythmic focal spikes or rhythmic sharp activity in the Rolandic region; (2) 5 cases with complex focal seizures and progressive appearance of polymorphic delta- activity in 1 temporo-occipital region recurring independently; (3) 4 cases with focal complex seizures with motor manifestations. Ictal EEG showed flattening or fast activity in 1 frontotemporal region followed by unilateral fast poly-spikes in alternating clusters in both hemispheres. The focal seizures were refractory to antiepileptic drugs, and all patients except 3 had severe developmental delay. Migrating focal seizures in infancy is a newly defined and rare, but underrecognized, epileptic encephalopathy.