Sporadic Creutzfeldt–Jakob disease presenting as nonconvulsive status epilepticus case report and review of the literature

Creutzfeldt–Jakob disease (CJD) is the most common transmissible human spongiform encephalopathy. Seizures and status epilepticus (SE) are an uncommon finding in CJD. We report a 64-year-old woman with rapid cognitive decline who had electroencephalographic (EEG) changes suggestive of nonconvulsive status epilepticus (NCSE). She was later diagnosed with sporadic CJD (sCJD). We also reviewed the literature for published cases on this topic. MEDLINE was employed to identify all published reports of CJD and SE. We identified 8 references with a total of 12 cases with CJD and NCSE. sCJD should be considered in the differential diagnosis of any patient who presents with rapid cognitive decline and EEG changes consistent with status epilepticus.     

Status epilepticus and tiagabine therapy revisited

PURPOSE: To determine whether antiepileptic treatment with tiagabine (TGB) is associated with an increased frequency of nonconvulsive status epilepticus (NCSE) in patients with refractory epilepsy. METHODS: We reviewed retrospectively the medical and EEG records of all inpatients with refractory localization-related epilepsy at the National Society for Epilepsy treated with TGB between January 1997 and December 2000. Clinical and electroencephalographic (EEG) data before, during, and after TGB therapy were evaluated in those patients who experienced a deterioration in seizure control suggestive of NCSE. Frequency of NCSE was determined in a comparable, non-TGB-treated patient population. RESULTS: Seven (7.8%) of 90 TGB-treated patients were identified who experienced episodes of electroclinically confirmed NCSE. Serial EEGs showed deterioration during TGB treatment, with resolution of abnormality on discontinuation of TGB in all seven patients. During the same observation period, 32 (2.7%) of 1,165 non-TGB-treated patients developed electroclinically defined NCSE. CONCLUSIONS: Treatment with TGB is associated with an increased frequency of NCSE in patients with refractory localization-related epilepsy.     

非惊厥性癫痫持续状态临床及脑电图表现四例

目的由于非惊厥性癫痫持续状态(NCSE)的临床表现及脑电图的变化在儿童和成人很难被识别,容易被误诊,本研究主要是探讨NCSE的临床特点及脑电图表现。方法收集我院诊治过的4例NCSE患者的临床资料及脑电图资料,分析其特点。结果 4例患者既往均有癫痫发作。例1患者停药后出现NCSE发作,例3、例4患者由于药物控制不佳,例2患者的NCSE均发生在惊厥发作后,每次发作持续时间从0.5h至3d不等。例2、例3及例4患者反复多次出现NCSE。4例患者均表现为行为异常,例1、例2及例4患者发作时不讲话,不能和外界进行交流,例3患者发作时构音不清。随访后发现例2、例3患者记忆力下降,例1、例4患者智能基本正常。从脑电图来看,均表现为持续性棘慢波发放。例1为失神发作癫痫持续状态,例2、例3及例4为部分性发作癫痫持续状态。结论 NCSE在早期易漏诊,反复NCSE可导致患者记忆力下降,如癫痫患者出现持续半小时以上的行为异常等表现,应急行脑电图检查明确是否NCSE,使用苯二氮卓类及抗癫痫药物可终止NCSE。     

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.     

Non-convulsive status epilepticus during lithium treatment at therapeutic doses

Abstract The purpose of this study is to report the case of a patient with normal lithium serum levels who developed non-convulsive status epilepticus (NCSE). A 52-year-old woman with bipolar disorder type I (DSM-IV) treated with lithium experienced bradypsychism and episodes of confusion and spatial disorientation without signs or symptoms of lithium intoxication. Lithium serum levels were in the normal range. A brain MR scan was negative; the electroencephalogram (EEG) revealed a background 3–4 Hz delta rhythm and diffuse spike discharges. Prompt EEG and clinical response to intravenous diazepam therapy was observed. Based on these findings, a diagnosis of NCSE was made and lithium therapy was withdrawn, resulting in symptom remission and EEG normalization. The treatment was resumed after two months to test the correlation between NCSE and lithium therapy. Resumption of therapeutic range lithium induced the same clinical symptoms and EEG patterns; the therapy was thus definitively discontinued. The present data—signalling the temporal correlation of clinical and EEG changes with drug administration and withdrawal—suggest that even in the therapeutic range lithium treatment may trigger NCSE onset in predisposed subjects.     

Lateralized and focal clinical, EEG, and FLAIR MRI abnormalities in Creutzfeldt-Jakob disease.

OBJECTIVE: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive fatal prion disorder with typical clinical findings of dementia, motor dysfunction, and myoclonus and characteristic electroencephalographic (EEG) findings of bilateral synchronous periodic sharp waves. Advances in neuroimaging capabilities with diffusion-weighted and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) techniques have shown promise in the non-invasive diagnosis of CJD. This series illustrates the correlation between the lateralized and focal clinical, EEG, and MRI FLAIR sequence abnormalities in 8 patients (7 men and one woman 55-73 years old) with CJD. METHODS: A case series of 8 patients, evaluated at Mayo Clinic, who had a history of rapidly progressive lateralized or focal neurologic dysfunction and laboratory findings consistent with CJD between 1996 and 1999 were identified. EEG, MRI of the head with FLAIR sequence, and cerebrospinal fluid studies were performed in all patients. RESULTS: Mean time to death from symptom onset was 4 months. Symptoms were lateralized to the left hemisphere in 5 patients and to the right hemisphere in two. One patient showed bilateral occipital lobe involvement. In all patients, the EEG showed lateralized or focal periodic sharp waves that colocalized with clinical cerebral dysfunction. FLAIR MRI images revealed increased signal in the cortical ribbon and deep gray matter corresponding to the lateralized clinical and EEG findings in 7 patients. The other patient had bilateral occipital increased signal on FLAIR MRI. CONCLUSIONS: CJD may present with lateralized or focal cortical syndromes with colocalizing EEG and MRI findings. With the appropriate clinical history and laboratory evaluation, the corresponding areas of increased signal on FLAIR MRI provide supportive evidence of the disease. SIGNIFICANCE: CJD can sometimes present with more focal or lateralized clinical findings, and the colocalizing EEG and MRI findings can help make or confirm the diagnosis of CJD.     

Diagnosis of nonconvulsive status epilepticus (NCSE) in adults with altered mental status: clinico-electroencephalographic considerations

The high incidence of nonconvulsive status epilepticus (NCSE) and difficulties encountered in rapid diagnosis have only recently become apparent and most neurophysiology textbooks have yet to fully address this topic. There is an immediate need to provide neurologists, neurology residents, and electroneurodiagnostic technologists with information to assist them in achieving early, accurate diagnosis of NCSE in patients they encounter on a daily basis. Instead of attempting to write a comprehensive review of the topic, we examined over 90 NCSE publications since 1972 and focused our efforts on extracting and summarizing those EEG and clinical considerations we found most useful for accurate diagnosis of NCSE in an adult population. The wide overlap between the clinical symptoms of NCSE and many other disorders causing change in mental status limits the usefulness of clinical measures for diagnosis. Those clinical parameters which have some utility are outlined. EEG testing and accurate interpretation is needed to identify NCSE in most instances. EEG patterns of NCSE are detailed and examples provided in order of progressive complexity. Timely treatment reduces patient risk for morbidity attributed to NCSE. Electroneurodiagnostic technologists who learn to recognize the entire spectrum of NCSE EEG patterns are better able to alert electroencephalographers to EEGs likely needing expedited review. This may facilitate early diagnosis if electroencephalographers determine that NCSE is indeed present. Electroencephalographers correlate the EEG pattern, clinical activity, and other diagnostic information to provide the treating medical doctors with an interpretation and recommendation in a timely manner. Lastly, EEG and clinical checklists and an algorithm which uses benzodiazepine response in conjunction with continuous EEG monitoring are provided to help reduce uncertainty in interpretation of equivocal EEG patterns of NCSE.     

Utility of bilateral Bispectral index (BIS) monitoring in a comatose patient with focal nonconvulsive status epilepticus

We report the case of a patient with an extensive right cerebral hematoma complicated by focal nonconvulsive status epilepticus (NCSE) in whom the use of the new bilateral BIS-Vista? monitor was helpful in managing profound sedation and antiepileptic treatment in the absence of continuous EEG monitoring (CEEG). The analysis of color density spectral array (CDSA) showed stereotyped changes indicative of recurrent focal nonconvulsive seizures (NCSz) and NCSE. We noted a close correlation between NCSz and BIS value changes. EEGs during working hours always confirmed the persistence of focal NCSE. After several days of sedation, CDSA disclosed a gradual resolution of NCSE that was also confirmed by electroencephalography. The patient died of cardiorespiratory complications a few days later.     

Nonconvulsive status epilepticus: clinical features and diagnostic challenges.

NCSE, once thought to be a rare disorder, should be considered in any patient presenting with an alteration in mental status of indeterminate cause. The psychiatrist needs to be aware of the different clinical characteristics of this disorder as well as similarities and differences from psychiatric disorders. A history of seizure is not necessary for the diagnosis, nor is motor activity necessarily associated with NCSE. An EEG is required to confirm the diagnosis and should be performed when possible, because early recognition and treatment may improve outcome. There is usually a good response to an intravenous benzodiazepine; when response has been delayed, other anticonvulsants have been used as adjuncts. The EEG is necessary to distinguish AS from CPS so that, when indicated, the proper long-term antiepileptic drug therapy can be started. Although NCSE has been described in the literature for many years, there is still a great need for carefully designed prospective studies to help define clear guidelines to assist in clinical and management decision making and, ultimately, to improve outcomes.     

Significance of atypical triphasic waves for diagnosing nonconvulsive status epilepticus

The aim of the study described here was to analyze findings in 15 cases who were admitted with nonconvulsive status epilepticus (NCSE) and whose EEGs featured atypical triphasic waves (ATWs). We also investigated whether ATWs are useful for diagnosing this condition. Mental status was assessed, and EEGs were recorded during/after the antiepileptic drug treatment. Eight patients had metabolic disorders and nine had intracranial pathology. The ATWs were unilateral focal in 5 cases and bilaterally asymmetrical focal in 10 cases. In 11 of the 15 cases, the ATWs disappeared and mental status improved after treatment. NCSE should be considered in any individual who presents in an acute confusional state and whose EEG reveals either unilateral or bilaterally asymmetric ATWs.     

Non-convulsive status epilepticus with marked neuropsychiatric manifestations and MRI changes after treatment of hypercalcaemia

We describe a 77-year-old woman who developed a confusional state, cognitive impairment, behavioural abnormalities and dysphasia after treatment of hypercalcaemia. Repeated EEG recording revealed rhythmic sharp-wave activity over the right parietal-occipital lobe. Magnetic resonance imaging (MRI) showed marked hyperintense signal changes bilaterally. The diagnosis of a non-convulsive status epilepticus (NCSE) was made. With antiepileptic treatment the patient improved and MRI as well as EEG changes were almost all reversible. NCSE is an important differential diagnosis of patients with neuropsychiatric symptoms and can develop after rapid lowering of serum calcium levels in hypercalcaemia.     

Oral ketamine controlled refractory nonconvulsive status epilepticus in an elderly patient

Nonconvulsive status epilepticus (NCSE) is a heterogeneous disorder with different seizure types and diverse etiologies, and is mainly characterized by altered consciousness. The recognition of NCSE is more challenging than generalized convulsive SE, and diagnosis and treatment are often delayed. Therefore, some cases can evolve into refractory SE and become pharmacoresistant even with GABAergic anesthetics. Herein we report the successful clinical experience of pharmacoresistant complex partial SE treated with ketamine. An elderly woman was profoundly stuporous and had relentless clonic movements of the right hand and forearm. Electroencephalography revealed repetitive periodic lateralized epileptiform discharges (PLEDs). There was a poor clinical response to standard anticonvulsants and GABAergic anesthetics. Both the clinical and electroencephalographic SE were controlled after intravenous ketamine therapy. Rebound refractory NCSE occurred about six days after discontinuing the intravenous ketamine, which was successfully terminated by oral ketamine treatment. There were no adverse effects observed.     

The interpretation of the EEG in stupor and coma

This review discusses a variety of causes of stupor and coma and associated electroencephalographic (EEG) findings. These include metabolic disturbances such as hepatic or renal dysfunction, which are often characterized by slowing of background rhythms and triphasic waves. Hypoxia and drug intoxications can produce a number of abnormal EEG patterns such as burst suppression, alpha coma, and spindle coma. Structural lesions, either supra- or infratentorial, are reviewed. EEGs in the former may show focal disturbances such as delta and theta activity, epileptiform abnormalities, and attenuation of faster frequencies. In infratentorial lesions, the EEG may appear normal, particularly with a pontine lesion. Some patients may be encephalopathic because of ongoing epileptic activity with minimal or no motor movements. This entity, nonconvulsive status epilepticus (NCSE), is difficult to diagnose in obtunded/comatose patients, and an EEG is required to verify the diagnosis and to monitor treatment. Several EEG patterns and their interpretation in suspected cases of NCSE such as periodic lateralized epileptiform discharges (PLEDs), bilateral independent periodic lateralized epileptiform discharges (BIPLEDs), generalized periodic epileptiform discharges (GPEDs), and triphasic waves are reviewed. Other entities discussed include the locked-in syndrome, neocortical death, persistent vegetative state, brainstem death, and brain death.     

Non-convulsive seizures and non-convulsive status epilepticus monitoring in the intensive care unit. A real need for the Gulf Cooperation Council countries

Continuous EEG (cEEG) monitoring in the intensive care unit (ICU) is essential for detecting non-convulsive seizures/status epilepticus (NCSs, NCSE). Currently there exist a number of continuous EEG monitoring systems adapted for use in the ICU. However, these systems have been trained using EEG data collected from healthy, neurologically intact patients with epileptic seizures, a very different patient population from ICU patients. The review consists of 2 parts, clinical and technological aspects. In the first one, we summarize the electroencephalographic aspects of NCSs/NCSE and other EEG patterns encountered in the ICU. In the second part, we explain how to develop a novel cEEG monitoring system to be used in Hamad Medical Corporation ICUs, Doha, Qatar, that is able to detect pathological EEG patterns commonly occurring in the critically ill patient. Real-time monitoring of seizure discharges, and other pathological EEG patterns will allow correct diagnosis and adequate treatment in a timely fashion.     

Ambulatory non-convulsive status epilepticus evolving into a malignant form

We retrospectively analysed the clinical characteristics, electroencephalogram (EEG) records, brain magnetic resonance imaging (MRI) scans, antiepileptic therapy and prognosis of a case series with ambulatory non-convulsive status epilepticus (NCSE) which evolved into a malignant form (mNCSE). mNCSE was defined as NCSE that continues or recurs five days or more after the onset of general anaesthesia, including those cases where NCSE recurs upon reduction or withdrawal of anaesthetic therapy. Four women and two men were studied. The mean age was 42.8?years (range: 19-63?years). Two of six patients had a previous diagnosis of epilepsy. Four patients died. Two patients had a good outcome with return to consciousness and activities of daily life, and one of these subjects developed temporal lobe epilepsy. In four patients, the cause of mNCSE was encephalitis. Clinical presentation was complex partial status epilepticus (CPSE) in three patients and generalised NCSE (GNCSE) in the other three. Two of the latter had encephalitis and one was diagnosed with progressive myoclonus epilepsy (PME) of Lafora type. The mean duration of the NCSE episode was 47.5?days (range: 9-139?days; SD: 53.1). In three patients, continuous or rhythmic focal epileptiform discharges were the EEG pattern at onset. In the other three, continuous rhythmic generalised spike-wave, polyspike-wave or sharp slow-wave complexes were observed. Antiepileptic treatment was heterogeneous and patients were treated with an average of 6.0 AEDs (range: 3-10; SD: 3.0). In summary, mNCSE is a severe epileptic condition that occurs often in the context of encephalitis or pre-existing epilepsy. Both CPSE and GNCSE may occur. Although high mortality is associated with mNCSE, some patients may survive with normal or good recovery.     

Nonconvulsive status epilepticus in children: clinical and EEG characteristics

BACKGROUND: Nonconvulsive status epilepticus (NCSE) is a highly heterogeneous clinical condition that is understudied in the pediatric population. OBJECTIVE: To analyze the epidemiological, clinical, and electroencephalograpic features in pediatric patients with NCSE. METHODS: We identified 19 pediatric patients with NCSE from the epilepsy database of the Comprehensive Epilepsy Center at, Columbia University between June 2000 and December 2003. Continuous electroencephalographic (EEG) monitoring was analyzed and chart review was performed. RESULTS: The patients ranged from 1 month old to 17 years of age. Five patients developed NCSE following convulsive status epilepticus (CSE), and a further 12 patients developed NCSE after brief convulsions. Two developed NCSE as the first manifestation during a comatose state following hypoxic events. Acute hypoxic-ischemic injury was the most frequent etiology of NCSE in our population (5 of 19; 26%), followed by exacerbation of underlying neurometabolic disease (4 of 19; 21%), acute infection (3 of 19; 16%), change in antiepileptic drug regimen (3 of 19;16%), refractory epilepsy (2 of 19; 11%) and intracranial hemorrhage (2 of 19; 11%). Six patients had associated periodic lateralized epileptiform discharges (PLEDs), one had generalized periodic epileptiform discharges (GPEDs). Five (5 of 19; 26%) patients died of the underlying acute medical illness. Periodic discharges were associated with worse outcome. CONCLUSION: The majority of our patients with NCSE had preceding seizures in the acute setting prior to the diagnosis of NCSE, though most of these seizures were brief, isolated convulsions (12 patients) rather than CSE (five patients). Prolonged EEG monitoring to exclude NCSE may be warranted in pediatric patients even after brief convulsive seizures. Prompt recognition and treatment may be necessary to improve neurological outcome.     

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.     

Atypical EEG findings in subacute sclerosing panencephalitis.

OBJECTIVE: To evaluate atypical electroencephalographic features in subacute sclerosing panencephalitis (SSPE) and to detect its relation to clinical features. METHODS: Twenty-two patients aged 2-17 years (mean 9.4 years) with definite diagnosis of SSPE were studied. Their clinical data and EEG records were reviewed retrospectively. All EEG records were analysed for features of periodic complexes (PCs) in relation to age, age at onset, clinical stage and the rate of progression as well as duration of the disease. RESULTS: Classical periodic complexes of SSPE were found in EEGs of 13 patients (group I). Atypical patterns were observed in EEGs of nine patients (group II). Two new atypical findings were identified: prolonged discharges which include sharp waves and slow waves for 4-7 s followed by suppression for 1-4s; and periodic complexes which consist of four or five sharp waves in every 2 s. We observed atypical EEG patterns were more frequently in Stage III, acute form, and the disease duration was longer than in the typical group. CONCLUSIONS: Atypical EEG patterns in SSPE might be related to the progression of the disease, but this theory needs further longitudinal studies. SIGNIFICANCE: We suggest atypical EEG patterns might be observed more frequently in patients with severe neurologic disability, more rapidly progressive disease and longer duration of disease.     

Non-convulsive status epilepticus of frontal origin as the first manifestation of Hashimoto's encephalopathy

Hashimoto's encephalopathy is an often misdiagnosed, life threatening, condition which improves promptly with steroid therapy. Since clinical manifestations are heterogeneous and non-specific, the diagnosis is often difficult. Several case reports of Hashimoto's encephalopathy presenting with partial or generalised seizures are described, but only a few have focused on status epilepticus as the first clinical manifestation. We report two patients presenting with repetitive and prolonged seizures characterised by progressive reduction in contact and reactivity associated with frontal/diffuse polyspike-and-wave activities. This condition, which can be interpreted as a form of non-convulsive status epilepticus (NCSE) of frontal origin, was refractory to antiepileptic drugs but responded promptly to high doses of intravenous steroid treatment. In cases of unexplained encephalopathy with EEG documentation of NCSE, the early recognition and treatment of Hashimoto's encephalopathy may lead to a favourable prognosis. [Published with video sequences].