Event-related potential (P300) in two epileptic cases with continuous spike-waves during slow wave sleep

We studied the P300 of two epileptic cases with almost continuous diffuse spike-wave discharges on sleep EEG: one with epilepsy with continuous spike-waves during slow wave sleep, and another with atypical benign partial epilepsy. These cases showed a marked prolongation of P300 latencies during nonconvulsive status epilepticus with continuous spike-waves during slow wave sleep. As they improved clinically and electroencephalographically, the latencies became normal. These findings indicate that P300 is a useful method to elucidate the pathophysiology of nonconvulsive status epilepticus with continuous spike-waves during slow wave sleep.     

Observation of continuous spike-waves during slow sleep in children with myelomeningocele

Cases Two patients with myelomeningoceles (MMC) and shunt-treated hydrocephalus are reported. At 5 and 7 years respectively, when they began presenting mental deterioration and behavioural disorders, sleep EEG showed continuous spike-waves during slow sleep (CSWS). Discussion These are the first cases of CSWS described in patients with MMC. The mechanisms of CSWS are considered. The role of hydrocephalus and the thalamic injuries found in one of the patients is discussed in detail. The usefulness of monitoring sleep EEG in patients with hydrocephalus or thalamic lesions is stressed, considering the effects of CSWS on the cognitive competencies and the soft or subclinical course that epilepsy complicated with CSWS may follow.     

Epilepsia partialis continua and cortical motor control: insights into physiology

Motor epilepsia partialis continua is a widely described variant of simple focal motor status epilepticus. However, few studies have addressed associated pathophysiological anomalies that may help us understand the cortical organization, basic functioning and control of voluntary movement. We describe the clinical, video‐EEG and neuroimaging findings from two cases of motor epilepsia partialis continua that support the hypothesis of the coexistence of both classic body and complex motor map models in the cortical organization of voluntary movement in humans. [Published with video sequence]     

Corticosteroids as treatment of epileptic syndromes with continuous spike-waves during slow-wave sleep

To assess the efficacy and tolerability of steroids in epileptic syndromes with continuous spike-waves during slow-wave sleep (CSWS), charts of 44 children (25 boys) who received corticosteroids for cognitive and/or behavioral deterioration associated with CSWS were retrospectively reviewed. Awake and sleep electroencephalography (EEG) records, clinical and neuropsychological assessments were available before, during, and after corticosteroid therapy. Evaluation focused on effects on EEG, behavior, and cognition. All but two patients received hydrocortisone (initial dose of 5 mg/kg/day). The treatment was slowly tapered with a total duration of 21 months. There were 18 symptomatic and 26 cryptogenic cases. Mean age was 7 years and mean intelligence quotient/developmental quotient (IQ/DQ) was 65. Mean CSWS duration before corticosteroid treatment was 1.7 years. Twenty patients had tried more than two antiepileptic drugs (AEDs) before steroids. Positive response to steroids was found during the first 3 months of treatment in 34 of 44 patients (77.2%), with normalization of the EEG in 21 patients. Relapse occurred in 14 of them. Hence, 20 patients (45.4%) were long-term responders after a single but prolonged trial of steroids, including all four cases of Landau-Kleffner syndrome. Positive response to steroids was highly significantly associated with higher IQ/DQ. Shorter CSWS duration, but not age, etiology, or previous AED trials, was associated with positive response to steroids. Early discontinuation of the treatment for side effects was encountered in seven patients. We conclude that corticosteroids are safe and efficient for treatment of epilepsy with CSWS. Poor responders are patients with very low IQ and long duration of CSWS.     

Epilepsia partialis continua in children with fulminant subacute sclerosing panencephalitis

Various inflammatory diseases of central nervous system, including subacute sclerosing panencephalitis, could cause epilepsia partialis continua. Two boys with epilepsia partialis continua with onset in terminal phase of atypical subacute sclerosing panencephalitis have been reported. Children were not vaccinated against measles, and the second case had history of measles at an early age. In both cases, the onset of subacute sclerosing panencephalitis was characterized by altered behavior and cognitive decline with very fast mental and neurological deterioration. One boy was suffering from complex partial seizures and myoclonic jerks synchronous with periodic electroencephalographic pattern. Diagnosis was proved by increased titers of antimeasles antibodies in both serum and cerebrospinal fluid. In terminal phase of the disease, epilepsia partialis continua of localized group of the muscles was diagnosed, with good response to intravenous infusion of midazolam. Surface electroencephalographic recordings during epilepsia partialis continua did not show the epileptic discharges. During the terminal phase of the disease, no other type of seizures and movement disorders were recognized, except epilepsia partialis continua. In spite of the treatment, period from the onset of disease to death lasted less than 3 months, suggesting very fulminant course of subacute sclerosing panencephalitis.     

Outcome at adulthood of the continuous spike-waves during slow sleep and Landau-Kleffner syndromes

PURPOSE: The aim of this study was to determine the clinical, social, and/or professional and cognitive outcomes in adulthood of the continuous spike-waves during slow sleep (CSWS) and Landau-Kleffner syndromes, which are two rare epileptic syndromes occurring in children. METHODS: We enrolled seven young adults, five who had a CSWS syndrome, and two, a Landau-Kleffner syndrome in childhood. We evaluated their intellectual level as well as their oral and written language and executive functions. RESULTS: This study confirmed that the epilepsy associated with these syndromes has a good prognosis. Only one patient still had active epilepsy. However, the neuropsychological disorders particular to each syndrome persisted. Only two patients had followed a normal pathway in school. Three of the five patients with a CSWS syndrome during childhood remained globally and nonselectively mentally deficient. We found no evidence of the persistence of a dysexecutive syndrome in this study group. The intellectual functions of the two patients with Landau-Kleffner syndrome were normal; however, their everyday lives were disrupted by severe, disabling language disturbances. We discuss the role of some prognostic factors such as the location of the interictal electric focus and the age at onset of CSWS. CONCLUSIONS: These two epileptic syndromes of childhood are very similar in many respects, but their clinical outcomes in adulthood are different.     

Epilepsia partialis continua in mitochondrial dysfunction: Interesting phenotypic and MRI observations

An 11-year-old girl manifested with photophobia, ptosis, external ophthalmoplegia, hypotonia, weakness of proximal limb muscles, hyporeflexia, and generalized seizures (six months). Her elder sister had had uncontrolled seizures and photophobia and died at seven years of age. In the patient, serum lactate was high (55 mg/dl). Muscle biopsy revealed characteristic ragged red and ragged blue fibers, diagnostic of mitochondrial cytopathy. Sequencing of the complete mitochondrial genome of the DNA obtained from the muscle biopsy of the patient did not show any characteristic mutation. Four months later, the girl was admitted with a one-week history of epilepsia partialis continua (EPC). EEG revealed Periodic Lateralized Epileptiform Discharges (PLEDs), once in 2-4 seconds, over the right temporo-occipital leads. MRI revealed signal change of right motor cortex, which had restricted diffusion. MR spectroscopy (MRS) from this region revealed lactate peak. EPC remained refractory to multiple anti-epileptic drugs, immuno-modulators, coenzyme-Q, and carnitine. This thought provoking report expands the spectrum of mitochondrial cytopathies.     

Personality profile and health-related quality of life in adults with previous continuous spike-waves during slow sleep syndrome

Introduction

Epilepsy with continuous spike-waves during slow sleep syndrome (CSWSS) is characterized by various seizure types, a characteristic EEG pattern and neuropsychological disorders. The main purpose of this study was to evaluate the long-term outcome of CSWSS occurred in childhood and to evaluate the variables that could influence the quality of social adaptation and the personality profile.

Epilepsia partialis continua in progressive multifocal leukoencephalopathy: a motor cortex isolation syndrome.

We describe the clinical and neuropathological features in a patient aged 45 years with progressive multifocal leukoencephalopathy with epilepsia partialis continua. The motor cortex and basal ganglia were preserved. Our findings lend support to the notion of isolation of the motor cortex as the cause of this particular type of focal status epilepticus.     

Epilepsia partialis continua associated with nonketotic hyperglycemia: Clinical and biochemical profile of 21 patients

In 21 patients, epilepsia partialis continua (EPC) was an early symptom of nonketotic hyperglycemia and occurred during an initial phase of hyponatremia and mild hyperosmolality. EPC persisted for an average of 8 days, and its duration correlated predominantly with the degree of hyponatremia. Depression of consciousness and cessation of seizures occurred with increasing severity of hyperglycemia and hyperosmolality. In 9 patients, EPC was the first symptom leading to the diagnosis of diabetes mellitus. Four patients died of serious associated illness. The majority of the patients had evidence of a localized structural cerebral lesion. Metabolic disturbances including hyperglycemia, mild hyperosmolality, hyponatremia, and lack of ketoacidosis contribute to the development of EPC in areas of focal cerebral damage.     

Epilepsia partialis continua: aetiology,semiology and prognosis in a Spanish adult cohort

Aim. To describe the semiological features in patients suffering with Epilepsia Partialis Continua (EPC), also referred as Kozhevnikov syndrome and their relationship with aetiology, duration, and prognosis, as well as recurrence during follow‐up. Methods. We analysed consecutive EPC patients diagnosed and followed in our centre over a seven‐and‐a half year period. We collected demographic and clinical data, along with neuroimaging and EEG recordings. All patients were followed for more than six months. Patients were categorised with single body area or multiple body area involvement according to the body parts affected. Recurrence was defined as a second EPC episode after one week. Results. We collected data from 27 adult patients; 70.4% were men, the mean age was 65.2 years old (range: 17–89 years), and 40.7% had previous epilepsy. EPC causes were structural in 85.1% (stroke being the most frequent; 44.4%), metabolic in 11.1%, and of unknown origin in 7.4%. A cortical lesion on neuroimaging was shown in 70.4%. Involvement of multiple body areas was reported in 55.6% of patients. The optimal cut‐off period to predict death was nine days (with a sensitivity of 62.5% and specificity of 75%; p=0.039), and this group of patients exhibited more multiple body area involvement (88.9% vs 38.9%; p=0.04). During follow‐up, patients with cortical lesions had more EPC relapses (p=0.037). Conclusions. The most frequent aetiology of EPC in our patients was stroke. Multiple body area involvement and duration were associated with mortality. Patients with cortical lesions had more EPC relapses during follow‐up.     

Scalp-recorded high-frequency oscillations in childhood epileptic encephalopathy with continuous spike-and-wave during sleep with different etiologies

Objective

To investigate high-frequency oscillations (HFOs) in epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) with different etiologies.

A prospective study of dexamethasone therapy in refractory epileptic encephalopathy with continuous spike-and-wave during sleep

PurposeEpileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) is an intractable form of epilepsy that has no consensus protocol for corticosteroid therapy. This prospective study aimed to evaluate the efficacy and tolerability of dexamethasone for the treatment of CSWS.MethodsPatients (age: 4 years to 12 years and 5 months) with CSWS that failed to respond to several antiepileptic drugs and prednisolone at our pediatric neurology outpatient clinic between 2007 and 2015 were treated with dexamethasone and prospectively analyzed. An initial 4-week dexamethasone (0.15 mg/kg/day p.o.) scheme was employed, and response was assessed. If effective, dexamethasone was maintained for 2–3 months and then slowly weaned over several months, depending on individual patient response at each follow-up. Systemic evaluations (clinical evaluations, electroencephalography recordings, and analysis of side effects) were performed regularly thereafter.ResultsAmong 15 patients, 7 were defined as initial responders after 4-week dexamethasone treatment based on comprehensive clinical and electroencephalogram evaluations. The duration of dexamethasone treatment (including weaning) in these 7 patients was 6 to 10 months, and the follow-up duration was 6 months to 7 years. Three patients had no relapse after dexamethasone withdrawal at last follow-up. Among the other 4 patients, relapse was observed during dexamethasone withdrawal (n = 1) or at 2–6 months after discontinuation of dexamethasone therapy (n = 3). There were no serious or life-threatening side effects, and all observed side effects were reversible after discontinuation of dexamethasone.ConclusionsContinuous oral dexamethasone treatment is an effective and tolerable therapy and should be an option for the treatment of CSWS.     

A prospective study of levetiracetam efficacy in epileptic syndromes with continuous spikes-waves during slow sleep

Purpose

To evaluate the add-on effect of levetiracetam (LEV) treatment on the EEG and clinical status of children with continuous spikes-waves during slow sleep (CSWS).

Methods

20 children with CSWS refractory to other conventional antiepileptic drugs (AEDs) received LEV 45–50 mg/kg/day as add-on treatment, and were prospectively followed for a minimum period of 18 months. The patient population comprised seven cryptogenic, seven symptomatic and six idiopathic cases (atypical benign partial epilepsy, aBECTs). The electrographic evaluation included 24 h EEG recordings taken every six months (minimum of three per child). Electrographically children were categorised as responders, partial responders or non-responders by comparing changes in the spike index (SI) during NREM-sleep with baseline SI before initiation of LEV. The clinical efficacy of LEV was assessed by comparing seizure frequency at the end of follow up with the baseline. The follow up duration varied from 18 to 53 months.

Results

Electrographic response was observed in 11 patients. Eight patients demonstrated a lasing response (more than 12 months): five from symptomatic, two – cryptogenic and one – idiopathic group respectively. Three children showed a partial response (6–12 months): one from symptomatic and two from idiopathic group.Eleven out of the 20 children were seizure free at baseline and during the whole follow up. The rest, six-symptomatic and three-cryptogenic patients, had seizures prior to LEV treatment initiation. Six became seizure free after add-on therapy with LEV, and in three children a significant reduction of seizure frequency was observed.

Conclusion

This study suggests that add-on therapy with LEV is more effective in children with CSWS resulting from a known underlying structural brain lesion (the symptomatic group).     

The epileptic syndromes with continuous spikes and waves during slow sleep: definition and management guidelines

The authors propose to define the epileptic syndromes with continuous spikes and waves during slow sleep (CSWS) as a cognitive or behavioral impairment acquired during childhood, associated with a strong activation of the interictal epileptiform discharges during NREM sleep--whatever focal or generalized--and not related to another factor than the presence of CSWS. The type of syndrome will be defined according to the neurological and neuropsychological deficit. These syndromes have to be classified among the localization-related epileptic syndromes. Some cases are idiopathic and others are symptomatic. Guidelines for work-up and treatment are proposed.     

Levetiracetam efficacy in epileptic syndromes with continuous spikes and waves during slow sleep: experience in 12 cases

PURPOSE: To assess the add-on efficacy of levetiracetam on the EEG, behavior, and cognition of children with continuous spikes and waves during slow sleep (CSWS). METHODS: Charts of children with behavioral and/or cognitive deterioration associated with CSWS who received levetiracetam at 50 mg/kg/day as add-on treatment were retrospectively reviewed. Awake and sleep EEG recordings and detailed neuropsychological and behavioral assessments were available at baseline and 2 months after levetiracetam initiation. In children showing clinical and/or electrophysiological improvement after 2 months, levetiracetam was continued with a new evaluation at 1 year. RESULTS: Twelve patients were included (9 cryptogenic and 3 symptomatic cases). Seven patients (58.3%) showed improvement of EEG record. Among these seven patients, neuropsychological evaluation was improved in three, and in the other four patients, not testable because of severe cognitive impairment, behavior was improved. Two patients improved in neuropsychological evaluation despite the lack of EEG improvement. Eight patients (66.6%) continued levetiracetam treatment after 2 months. After 1 year, four patients were still on levetiracetam, two because sustained effect on EEG and behavior and the two others because improvement in neuropsychological testing despite unchanged EEG. Levetiracetam was discontinued in the other four patients because of neuropsychological or behavioral deterioration associated with CSWS pattern, between 9 and 11 months after treatment initiation. CONCLUSIONS: This retrospective study suggests that levetiracetam has a positive effect on the EEG, the behavior, and the cognition of patients with epilepsy and CSWS. Additional studies are warranted in order to assess the place of this drug in these epileptic conditions.     

A new cause of developmental and epileptic encephalopathy with continuous spike-and-wave during sleep: CDKL5 disorder

The CDKL5 disorder is characterized by early onset epilepsy, stereotypical hand movement, absent speech and severe hypotonia. Herein, we report epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) in apatient with CDKL5 disorder. She admitted with complaints of frequently recurring generalized tonic and myoclonic seizures. The diagnoses were confirmed by de novo CDKL5 mutation, c.197_198delCT (p.L67QfsX23). Interictal EEG revealed generalized spike and slow-wave activity, occurring intermittently in wakefulness but present for at least 85% of non-REM sleep, consistent with the diagnosis of CSWS. To our knowledge, this is the first report of CSWS associated with CDKL5 disorder.