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.     

Beta activity in status epilepticus

Focal beta activity on scalp EEG is a rare seizure pattern that has most extensively been studied in patients undergoing evaluation for epilepsy surgery. However, ictal beta activity is uncommon beyond this population and has not been reported in human status epilepticus. We observed ictal focal beta activity as the predominant seizure pattern in a patient with refractory status epilepticus. Continuous left temporal beta activity clinically correlated with complex partial semiology on video-EEG.     

Electroencephalographic patterns in unresponsive pediatric patients

To study the occurrence and incidence of various electroencephalographic patterns, the electroencephalograms of unresponsive pediatric patients admitted to the intensive care unit were analyzed. The interpreters were unaware of the patients' clinical diagnoses. A total of 178 electroencephalographic studies performed on unresponsive patients were analyzed over a period of 3 years. The mean age of the study patients was 7.9 years. Sixty-six patients were less than 1 year old. The following electroencephalographic patterns were observed: 58 patients (33%) manifested electroencephalographic patterns consistent with nonconvulsive status epilepticus. Of the patients with nonconvulsive status epilepticus, 32 patients (18%) had generalized nonconvulsive status epilepticus and 26 patients (14%) manifested partial nonconvulsive status epilepticus. The remaining 120 patients (67%) manifested diffuse cerebral dysfunction, with the majority having severe diffuse cerebral dysfunction. Only 4 patients (2%) had triphasic waves, suggesting a metabolic encephalopathy. Thirty-six percent of the patients under the age of 1 year had electroencephalographic patterns consistent with nonconvulsive status epilepticus. Nonconvulsive status epilepticus is a relatively common electroencephalographic pattern in unresponsive pediatric patients. Metabolic encephalopathy is uncommon in this patient group.     

非抽搐性癫痫持续状态五例及文献复习

目的 探讨非抽搐性癫痫持续状态(NCSE)患者的临床表现及持续脑电监测的脑电图(EEG)特征.方法 对自2008年11月至2009年12月北京大学人民医院急诊科收治的5例NCSE患者行持续EEG监测检查,观察其EEG特征及临床表现.结果 5例均出现发作性意识障碍,其中4例出现烦躁、易怒或躁狂,3例表现出精神运动迟滞和遗忘,2例出现言语自动症和失认,1例出现定向障碍.所有患者的EEG均出现广泛性但一侧明显的异常放电.静脉注射地两泮后,3例患者临床症状迅速改善.结论 NCSE并非罕见,持续EEG监测能查出本病,早期诊断,及时治疗可改善患者预后,临床应注意与其他引起意识紊乱的疾病相鉴别.     

Tiagabine-related non-convulsive status epilepticus in partial epilepsy: three case reports and a review of the literature.

There have been several recent reports of non-convulsive status epilepticus during tiagabine therapy in patients with partial epilepsy. We report three cases where elevation of tiagabine dosage was followed by electroclinical features, or electroencephalographic features without clinical signs, of non-convulsive status epilepticus. Administration of clonazepam and/or discontinuation to tiagabine lead to complete remission. In one case after re-exhibition of tiagabine the EEG again showed rhythmic delta waves. We review the other cases reported so far and discuss the different pathophysiological hypotheses about the association in the light of new experimental data.     

Treatment of seizures in subcortical laminar heterotopia with corpus callosotomy and lamotrigine.

Focal and generalized cortical dysgeneses are sometimes seen on the magnetic resonance images (MRI) of patients with epilepsy. Subcortical laminar heterotopia are bilateral collections of gray matter in the centrum semiovale that resemble a band or "double cortex" on MRI. We studied one male and two female patients with subcortical laminar heterotopia who had moderate to severe developmental delay, early-onset epilepsy, and medically refractory seizures. Atonic, atypical absence, tonic, myoclonic, complex partial, and generalized tonic-clonic seizures were recorded. Interictal and ictal electroencephalographic patterns were generalized and, less commonly, multifocal. Two years after corpus callosotomy, one patient was free of generalized tonic-clonic and atonic seizures, but the other patient who had undergone callosotomy had no significant reduction in seizure frequency. With lamotrigine treatment, the patient who had not had surgery had complete cessation of monthly episodes of status epilepticus and a dramatic reduction of generalized tonic-clonic seizures, and the other patient who received lamotrigine had a 50% reduction of her atonic seizures. In patients with subcortical laminar heterotopia, atonic and generalized tonic-clonic seizures can be substantially reduced or eliminated by corpus callosotomy or treatment with lamotrigine.     

Anxiety as the only manifestation of focal non-convulsive status epilepticus: case report and review of the literature

ABSTRACT

Psychiatric disorders represent common comorbidities in epileptic patients. Sometimes anxiety is part of the ictal semiology, especially during seizures arising from/involving frontal or temporal lobes. We describe a patient with focal epilepsy and recurrent hyperkinetic seizures who also presented prolonged episodes characterized by massive anxiety, alarm and fear. A Video-Electroencephalographic monitoring performed during one of these attacks revealed a continuous epileptiform activity over the right frontal regions, consistent with a focal non-convulsive status epilepticus accounting for the patient’s psychiatric symptoms. Our case confirms the complex relationship between epilepsy and anxiety. A review of the literature is also included.     

Gaucher disease: successful treatment of myoclonic status epilepticus with levetiracetam

We present the first reported case of a rapid clinical and electroencephalographic response to intravenous levetiracetam infusion of myoclonic status epilepticus in a patient with progressive myoclonus epilepsy due to Gaucher disease. Under continuous video-EEG monitoring, the clinical myoclonic status and the electrographic ictal discharges resolved within 10 minutes after the infusion was initiated. The patient tolerated the treatment well without any reported side effects. This case suggests that levetiracetam may be a safe, effective, and well tolerated intravenous drug in patients with metabolic myoclonic status epilepticus such as Gaucher disease.     

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.     

Nonconvulsive Status Epilepticus in Adults: Thirty-Two Consecutive Patients from a General Hospital Population

We studied all adult patients who between 1984 and 1989 were initially diagnosed at our hospital as having nonconvulsive status epilepticus. Thirty-two patients fulfilled the criteria, which included ictal EEG recordings. The annual incidence was 1.5 in 100,000 inhabitants. The median age at onset of status was 51 years. Ten patients had status as their first epileptic manifestation, but most patients had a previous history of epilepsy. Median duration of epilepsy at onset of status was 4 years. Fourteen patients had focal ictal seizure activity on EEG and thus met the criteria for complex partial status. Eighteen patients had generalized seizure activity on EEG, but only 6 of these had a history of absence epilepsy or juvenile myoclonic epilepsy. None had Lennox-Gastaut syndrome. The clinical features of status in the remaining 12 patients were in some respects similar to those of the patients with complex partial status. We hypothesize that the EEG seizure activity in these patients may have been generalized from an initial focus.     

Non-convulsive status epilepticus presenting with Wernicke's aphasia

Ictal aphasia in adults is a rare phenomenon. Most reported cases manifest with non-fluent (Broca) aphasia. Ictal fluent (Wernicke) aphasia is less common. We report a 47-year-old, right-handed woman that presented with recurrent episodes of non-convulsive seizures in the form of Wernicke's aphasia for 2 weeks. An MRI of the brain showed an old cerebral infarction in the left parieto-occipital area. Scalp EEG revealed continuous periodic sharp waves at the left temporal regions with diffusion to the whole left hemisphere and at occasions to the right. This is followed by variable periods of post ictal slowing. Recurrence of the described ictal pattern was noted. Management of status epilepticus was started in the form of intravenous diazepam and a loading dose of phenytoin and phenobarbitone. After treatment, she improved clinically and the EEG improved with disappearance of the left temporal ictal rhythm and normalization of the EEG background. Thus, establishing the diagnosis of non-convulsive partial status epilepticus manifesting as ictal aphasia.     

A progressive sequence of electroencephalographic changes during generalized convulsive status epilepticus

Review of 60 electroencephalograms recorded during episodes of generalized convulsive status epilepticus suggested that there are 5 identifiable EEG patterns which occur in a predictable sequence during the course of generalized convulsive status epilepticus in man: (1) discrete seizures; (2) merging seizures with waxing and waning amplitude and frequency of EEG rhythms; (3) continuous ictal activity; (4) continuous ictal activity punctuated by low voltage 'flat periods'; and (5) periodic epileptiform discharges on a 'flat' background. We confirmed our hypothesis that this sequence represents the natural history of electroencephalographic changes in untreated generalized convulsive status epilepticus by observing the same sequence in the EEGs of rats in which status epilepticus had been induced by 3 different methods: (1) systemic administration of kainic acid, (2) injection of homocysteine thiolactone to cobalt-lesioned rats; and (3) injection of lithium chloride followed 24 h later by injection of pilocarpine.     

Drug resistant ADLTE and recurrent partial status epilepticus with dysphasic features in a family with a novel LGI1mutation: electroclinical, genetic, and EEG/fMRI findings

Purpose:   We characterized a family with autosomal dominant lateral temporal epilepsy (ADLTE) whose proband presented uncommon electroclinical findings such as drug-resistant seizures and recurrent episodes of status epilepticus with dysphasic features.
Methods:   The electroclinical characteristics and LGI1 genotype were defined in the family. In the proband, the ictal pattern was documented during video-EEG monitoring and epileptic activity was mapped by EEG/fMRI.
Results:   The affected members who were studied had drug-resistant seizures. In the proband, seizures with predominant dysphasic features often occurred as partial status epilepticus. The video-EEG-documented ictal activity and fMRI activation clearly indicated the elective involvement of the left posterior lateral temporal cortex. Sequencing of LGI1 exons revealed a heterozygous c.367G>A mutation in exon 4, resulting in a Glu123Lys substitution in the protein sequence.
Conclusions:   The uncommon clinical pattern (high seizure frequency, drug-resistance) highlights the variability of the ADLTE phenotype and extends our knowledge of the clinical spectrum associated with LGI1 mutations.     

Non-convulsive status epilepticus of frontal origin in mucopolysaccharidosis type II successfully treated with ethosuximide

At 7 years of age, a female with mucopolysaccharidosis type II (MPS II) showed a sudden deterioration in neurological function, a sleep disorder, and progressive behavioural impairment. Electroencephalography was performed 1 year and 8 months after the onset of the neurological regression and revealed continuous ictal activity in the frontal regions. The female was diagnosed as having frontal non‐convulsive status epilepticus. After 5 weeks of therapy with ethosuximide, the ictal electroencephalographic activity disappeared. At the same time, her sleep and cognitive and behavioural functions were observed to improve. This is the first case of MPS type II reported in an individual with non‐convulsive status epilepticus. Two main forms of MPS II can be recognized: attenuated and severe. Severe MPS II is characterized by neurodegeneration. No study has explored the relationship between epilepsy and neurological deterioration in MPS II. Our observation shows that epilepsy may be a treatable cause of neurological regression in individuals with MPS II.     

Nonconvulsive status epilepticus precipitated by carbamazepine presenting as dissociative and affective disorders in adolescents

Nonconvulsive status epilepticus can be confused with psychiatric disorders. Inappropriate drug treatment can represent a precipitating factor. We describe two patients with idiopathic generalized epilepsy in whom nonconvulsive status epilepticus, aggravated by carbamazepine, was misdiagnosed as psychiatric disorder. A 14-year-old girl experienced a tonic-clonic seizure at age 12 years preceded by monthly episodes of confusion with awkward behavior since age 9 years. She was treated with carbamazepine, and the episodes of confusion became more frequent, leading to a diagnosis of dissociative disorder. An electroencephalogram during one of these episodes revealed nonconvulsive status epilepticus. Substitution of carbamazepine with valproic acid controlled the episodes of status epilepticus. A 23-year-old woman presented at age 16 years with a tonic-clonic seizure. Since early adolescence, she had had episodes of depressive mood, worsening of school performances, and facial tics. Carbamazepine treatment caused worsening of the depressive episodes and facial tics. An electroencephalogram during a typical episode revealed nonconvulsive status epilepticus. Carbamazepine substitution with valproate led to seizure freedom and behavioral improvement. Nonconvulsive status epilepticus should be suspected and searched for in patients with epileptic seizures and ictal or fluctuating behavioral disorders.     

Topiramate and status epilepticus: report of three cases

OBJECTIVE: The goal of this study was to report the effectiveness of topiramate in treating status epilepticus. METHODS: Three patients with status epilepticus were treated with topiramate 500 mg twice daily for 2-5 days, with the dose gradually tapered thereafter to 200 mg twice daily. The patients' clinical status and EEG recordings were followed. RESULTS: Patient 1 was admitted for subacute encephalopathy that was complicated by secondarily generalized status epilepticus resistant to lorazepam, fosphenytoin, and pentobarbital coma. Topiramate was added and, 2 days later, pentobarbital was tapered with no recurrence of ictal discharges as the patient improved clinically. Patient 2 had end-stage liver disease and was hospitalized for peritonitis, and his course was complicated by partial status epilepticus. Topiramate was started and, 2 days later, his mental status improved as repeat EEG showed no further ictal discharges although periodic epileptiform discharges were seen in the left centroparietal area. The patient later died from complications of variceal bleeding. Patient 3 suffered cardiopulmonary arrest, and developed postanoxic seizures, which did not respond to lorazepam, fosphenytoin, valproate, and propofol coma as continuous EEG recordings showed recurrent generalized ictal discharges. Two days after topiramate was started, propofol was tapered and discontinued and EEG showed generalized slow wave activity and no ictal discharges. The patient was discharged to another facility 12 days later. CONCLUSIONS: Topiramate was effective in treating two patients with refractory generalized status epilepticus and one with complex partial status epilepticus. It should therefore be considered as an option in these situations, especially when other medications cannot be used.     

Myoclonic status epilepticus: a clinical and electroencephalographic study

We reviewed the clinical features and ictal EEGs in 23 adults with myoclonic status epilepticus (MSE). Anoxic encephalopathy was the most common cause of MSE, occurring in 15 patients; 8 developed MSE within 14 hours following the anoxic insult. Metabolic encephalopathies were present in 4 patients, while 2 had degenerative CNS disorders. In 2 patients with generalized epilepsy, MSE developed during a medication change. Five types of EEG patterns were associated with MSE. Generalized periodic complexes (usually spikes, polyspikes, or sharp waves), often with attenuation of background activity between complexes (11 patients) or a burst-suppression pattern (4 patients), were the most common types. Outcome was poor: 20 patients died without regaining consciousness, while 1 remains in a vegetative state. The 2 patients with generalized epilepsy, both of whom were conscious during MSE, survived without sequelae.     

Cortico-thalamic activation in generalized status epilepticus, a PET study

In a patient with a refractory generalized convulsive status epilepticus, the ictal distribution of regional cerebral glucose was assessed with positron emission tomography (PET). Synchronized seizure activity in the EEG was associated with bilateral metabolic activation of medial sensorimotor regions, anterior cingulate cortex, striatum and thalamus. This pattern with focal cortical activation supports the concept that a cortical focus may drive epilepsy, while the thalamus mediates synchronization of neuronal activity as reflected in the EEG.