Focal Nonconvulsive Status Epilepticus Research Articles

Ictal pain in focal non-convulsive status epilepticus

We report an adult with acute unilateral pain as isolated manifestation of acute symptomatic focal non-convulsive status epilepticus. Pain is rarely a manifestation of epileptic seizures. Traditionally, painful seizures have...

Should Posterior Reversible Encephalopathy Syndrome Be Mainly Considered an Epileptic Disorder? Results of a Sequential Neurophysiological Study in a Pediatric Cohort.

Despite a wide number of studies trying to define clinical, physiopathological, and neuroradiological features of posterior reversible encephalopathy syndrome (PRES), the true nature of symptoms is still not fully understood. We studied a standard cohort of 24 pediatric patients, affected by hemato-oncological diseases, with a neuroradiological diagnosis consistent with PRES identified from 2006 to 2013. Ten of them developed PRES after hematopoietic stem cell transplantation. We analyzed the sequence of clinical, radiological, and electrophysiological data. In all the patients who were recorded at the onset of the first symptoms, electroencephalograms showed focal nonconvulsive seizures or status epilepticus (SE). We found a sensitivity of 100% for electroencephalogram (EEG) with a good correlation between clinical signs and the localization of seizures, whereas computed tomography scans showed a sensitivity of 50% only. Following prompt treatment, intensive care unit admission rate was only 8%. PRES is a multifactorial neurologic event with focal nonconvulsive seizures or SE as the main feature in pediatric patients. Clinical manifestations are epileptic in nature, and prompt EEG recording is useful for diagnosis and supports an earlier treatment, potentially preventing the appearance of complications such as generalized seizures or refractory SE.

Anti-NMDA-R encephalitis: Should we consider extreme delta brush as electrical status epilepticus?

Seizures are common clinical manifestations in anti-N-methyl-d-aspartate receptor (anti-NMDA-R) encephalitis, among other neurological and psychiatric symptoms. During the course of the disease, some specific EEG patterns have been described: generalized rhythmic delta activity (GRDA) and extreme delta brush (EDB). In comatose patients, the association of these EEG abnormalities with subtle motor manifestations can suggest ongoing non-convulsive status epilepticus (NCSE). We report the case of a 28-year-old woman admitted for a clinical presentation typical of anti-NMDA-R encephalitis, which was confirmed by CSF analysis. She was rapidly intubated because of severe dysautonomia and disturbed consciousness. Clinical examination revealed subtle paroxysmal and intermittent myoclonic and tonic movements, correlated on video-EEG with GRDA and/or EDB. NCSE was then suspected, but electroclinical manifestations persisted despite many anti-epileptic drugs combinations, or reappeared when barbiturate anesthesia was decreased. In order to confirm or dismiss the diagnosis, intracranial pressure (ICP) and surface video-EEG monitoring were performed simultaneously and revealed no ICP increase, thus being strongly against a diagnosis of seizures. Sedation was progressively weaned, and clinical condition as well as EEG appearance progressively improved. Literature review revealed 11 similar cases, including 2 with focal NCSE. Of the nine other cases, NCSE diagnosis was finally excluded in 5 cases. NCSE diagnosis in association with anti-NMDA-R encephalitis is sometimes very difficult and its occurrence might be overestimated. Video-EEG is highly recommended and more invasive techniques may sometimes be necessary.

Variable electrobehavioral patterns during focal nonconvulsive status epilepticus induced by unilateral intrahippocampal injection of kainic acid.

Nonconvulsive status epilepticus (ncSE) is a severe condition that may result in neurologic sequelae and epilepsy resistant to pharmacologic treatment. We analyze here seizure and electroencephalography (EEG) patterns and their correlation to the development of a chronic epileptic condition in a guinea pig model of focal ncSE induced by intrahippocampal injection of kainic acid (KA). Electrobehavioral patterns during ncSE induced by unilateral injection of 1μg of KA in the CA1 region of the hippocampus were characterized by continuous video-EEG monitoring in 13 guinea pigs bilaterally implanted with recording electrodes in the hippocampus and neocortex. Video-EEG analysis demonstrates a high variability of seizure type and duration during KA-induced ncSE. Seizures showed focal signs correlated with diverse epileptiform EEG discharge distributions, either diffuse or localized. Nonfocal (bilateral motor) signs during seizures most likely correlated with a diffuse EEG pattern. The evolution into a chronic epileptic condition correlated neither with the severity of seizure pattern nor with the diffusion of the EEG discharges observed during the ncSE. Video-EEG monitoring in a guinea pig model of ncSE induced by unilateral hippocampal injection of KA demonstrates a high variability of electrobehavioral patterns. We demonstrate that the seizure severity score during focal ncSE is not a predictor of the evolution into a chronic epileptic condition of mesial temporal lobe epilepsy.

Cognitive dysfunction with complex visual hallucinations due to focal nonconvulsive status epilepticus: A neuropsychological study and SISCOM

A 74-year-old woman with left hemiparesis due to a previous stroke presented with the sudden development of cognitive impairment and episodic complex visual hallucinations as manifestations of nonconvulsive status epilepticus (NCSE). Neuropsychological tests performed during NCSE demonstrated deficits encompassing several cognitive domains. The short-lasting complex visual hallucinations were stereotypical, vivid, and accompanied by intense fear. The seizure activity in the right temporo–parieto–occipital region, as documented by SISCOM and electroencephalogram (EEG) recording, was thought to be due to an unusual clinical presentation of NCSE. Subcortical cerebromalacia likely blocked the propagation route, restricting the ictal activities within this area.

Bálint‐like syndrome as an unusual representation of non‐convulsive status epilepticus

The clinical signs of posterior cortex dysfunction are, due to their paucity and subtlety, very often ignored as non-specific during clinical evaluation of non-convulsive status epilepticus. Therefore, focal non-convulsive status epilepticus emerging from the posterior cortex, and especially the parietal lobes, can be fairly under-recognised. We report a 66-year-old patient with focal non-convulsive status epilepticus presenting as isolated Bálint-like syndrome, successfully treated to full clinical and electrophysiological recovery. The diagnostic and pathophysiological features are discussed. Focal non-convulsive status epilepticus can be associated with negative phenomena such as neuropsychological deficits mimicking those detected more often in degenerative and vascular brain diseases. [Published with video sequences].

Intravenous Lacosamide in refractory nonconvulsive status epilepticus

BackgroundMany patients present with refractory Status epilepticus (SE) despite multiple anti-epileptic drugs (AEDs). Lacosamide (LCM) was recently approved as an adjunct AED for partial-onset seizures. It has unique mechanism of modulating voltage-gated sodium channels by enhancing their slow inactivation. LCM has demonstrated efficacy in animal models of pharmacoresistant seizures. To date, there are isolated anecdotal reports of LCM use in SE. ObjectiveTo report a single center experience with IV Lacosamide in patients with NCSE. MethodsPharmacy records were reviewed to identify patients with SE who received IV LCM in our institution. Data on demographics, response to therapy and adverse effects/outcomes were analyzed. All patients had continuous EEG monitoring. Results10 patients (4 men, 6 women), age 16–90 years with refractory SE were given LCM. Eight patients were in focal non-convulsive SE (NCSE), 2 were in generalized non-convulsive SE. The etiologies included anoxic brain injury, idiopathic, encephalitis, tumor, posterior reversible encephalopathy syndrome (PRES), stroke, and AVM. IV LCM was added after traditional AEDs, including drug-induced coma in some, failed to control the SE. NCSE resolved in 7/10 patients whereas 1/10 patient showed partial response with cessation of NCSE but still frequent electrographic seizures and 2/10 patients were resistant to therapy. ConclusionsLCM is a useful adjunct in refractory NCSE. The IV formulation allows prompt administration in the intensive care unit setting. Response was seen especially in focal SE. Similar to other AEDs, response was poor in patients with postanoxic injury. Our data is limited by the small number of patients. Larger controlled studies are necessary to assess accurately the efficacy of IV LCM as an early treatment of SE.

Anti-NMDA Receptor Encephalitis Presenting with Focal Non-Convulsive Status Epilepticus in a Child

A previously healthy 9-year-old girl presented to an emergency department (ED) with headache, dizziness, blurry vision, and abnormal visual perceptions. She was diagnosed with migraine, treated symptomatically, and discharged. Over the course of days, she became progressively somnolent, and returned to the ED, where she was found to have a right inferior quadrantanopsia and sixth nerve palsy. Magnetic resonance imaging (MRI) of the brain showed gyral swelling of the left parieto-occipital lobe. Continuous electroencephalogram (EEG) monitoring revealed focal non-convulsive status epilepticus (NCSE) in the left occipital region. Cerebrospinal fluid (CSF) was positive for antibodies directed against the N-methyl-d-aspartate receptor (NMDAR). This case is the first report of anti-NMDAR encephalitis presenting with focal non-convulsive status epilepticus (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.

Cyclic hyperammoniemic encephalopathy and epileptiform triphasic waves: problems in differential diagnosis with nonconvulsive status epilepticus

Dear Editor, We would like to make three points about the case of cycling hyperammoniemic encephalopathy in an old women with a past history of uterosigmidostomy discussed by Tremolizzo et al. [1]. The first point concerns diagnosis of nonconvulsive status epilepticus (NCSE). De novo NCSE is not infrequent in elderly patients but as emphasized by Walker et al. [2] the diagnosis is often made with significant delay because the clinical picture of NCSE is difficult to differentiate from that of a metabolic encephalopathy unless an EEG is obtained. NCSE is under-recognized in clinical practice and a high level of suspicion is essential. There is the low awareness among physicians of the diagnostic utility of emergent EEG [3]. The second point is that a large spectrum of EEG ictal abnormalities may be observed in NCSE, including triphasic wave (TWs) with epileptiform characteristics. In particular, Kaplan (1999) [4] stressed that ‘‘when TWs appear with a frequency exceeding 1/s the distinction between encephalopathy and NCSE is difficult’’ and reported an EEG tracing showing flurries of triphasic waves (TWs) in a waxing and waning pattern in a patient with hyperammonemia. These EEG abnormalities are very similar to EEG pattern reported by Tremolizzo et al. Differential diagnosis between TWs of metabolic encephalopathy versus spike wave stupor was previously discussed [4]. In these cases it is mandatory to search a risk factor of mental status impairment (toxic-metabolic encephalopathy, as electrolytic imbalance, drugs toxicity, renal or liver failure, etc.) [5]. Finally, the immediate administration of benzodiazepines (lorazepam, diazepam) is the unequivocal first step for the treatment of NCSE. Bolus administration of intravenous valproic acid or phenytoin may be tried beyond benzodiazepines, but phenytoin should be used only in focal NCSE as it may cause aggravation of absence status [5].

Non-convulsive status epilepticus in adults - an overview

Status epilepticus (SE) is the most frequent neurological emergency requiring admission on the intensive care unit (ICU). The classification of status epilepticus may be dichotomised into the and the form. Whereas the diagnosis of generalised convulsive status epilepticus (GCSE) is easily made in view of the evident manifestation, the diagnosis of non-convulsive status epilepticus (NCSE) may become very difficult according to its non-spectacular and protean presentation. Non-convulsive status epilepticus is a common cause of altered mental status and delirium; and a substantial number of comatose patients in the intensive care unit may suffer from NCSE. The most important part of making a diagnosis of NCSE is to think of it at all. The definite diagnosis of NCSE is dependent on electroencephalographic (EEG) confirmation. Repetitive or, optimally, continuous EEG recording may help to closely monitor seizure activity and to guide the therapy in order to protect the patient from under- and/or over-treatment. The interpretation of EEG recordings of NCSE may become challenging because of numerous artifacts caused by the patient, caregivers and devices, and because of trace elements of ambiguous significance and of waveforms mimicking epileptic activity. Non-convulsive status epilepticus was historically subdivided into the groups of complex-partial status epilepticus (focal; CPSE) and absence status (generalised; AS). Most recently, a classification proposed by the International League Against Epilepsy (ILAE) has subdivided focal NCSE into aura continua (non-convulsive simple partial with maintained consciousness) and into dys-cognitive (with impaired consciousness) of mesial temporal or neocortical origin. Several patients with focal NCSE or AS were known for pre-existing epilepsy. In addition, other types of NCSE have been reported, like subtle where convulsions in patients with GCSE clinically stop, but the continuous epileptic activity electroencephalographically still persists. Another variant belongs to those patients with critical illness where the serious disorder and/or medications may trigger an acute, prolonged and all too often very-hard-to-treat epileptic condition (critical illness SE [CISE]). The majority of these patients will never have had seizures before. Of note, none of the currently proposed classifications has gained broad acceptance and official approval. Since the need for immediate and intensive treatment of GCSE is beyond debate, the insidiously calm presentation of NCSE may mislead to a much less aggressive therapeutic approach. However, experimental and clinical data suggest that continuous epileptic activity in the brain during NCSE associated with consecutive (glutamatergic) hyperexcitation triggers neurotoxicity and proapoptotic mechanisms which eventually may lead to irreversible brain damage and the onset of a chronic epileptic disorder or to an irreversible neurological deficit. Thus, recent national and international guidelines and reviews recommend immediate and intensive treatment for NCSE as well as for GCSE. With a few exceptions, the first drug is an intravenous benzodiazepine, mainly lorazepam; intravenous phenytoin or valproate should be started without delay. Persistence of NCSE after administration of these two classes of drugs heralds refractory (RSE) where single or combinations of drugs in anaesthetic dosages requiring intubation and enteral antiepileptics may be added except for the cases of AS or an underlying terminal disease. The outcome of NCSE is mainly determined by the type, duration, cause and the severity of concomitant diseases.

Ictal neuropsychological findings in focal nonconvulsive status epilepticus

Objective This study was intended to describe the neuropsychological phenomenology of focal nonconvulsive status epilepticus (NCSE). Methods Ictal, postictal, and interictal neuropsychological testing (NPT) was performed on six patients who developed NCSE during video/electroencephalographic monitoring in the context of presurgical evaluation. Results Neuropsychological impairments were marked in four of six and discrete in two of six patients. The majority of patients had selective rather than global neuropsychological deficits. The most important deficits involved consciousness, speech, praxis, cognitive functions, and affect. Impairment of consciousness was characterized by reduced vigilance, reactivity, and orientation. Some patients exhibited combined deficits of several higher cognitive functions (apraxia, acalculia, alexia, and aphasia with or without additional memory disturbance). Several patients had relatively subtle expressive or receptive aphasia. More severe language deficits were associated with reduced vigilance. Speech deficits may have caused poor performance in other areas evaluated with NPT. Conclusion NPT demonstrated that focal NCSE can be associated with pleomorphic but often discrete neuropsychological deficits.

Electroencephalogram in unilateral multilobar polymicrogyria with nonconvulsive status epilepticus

This case report presents the epileptic encephalopathy in an 11-year-old girl with multilobar unilateral polymicrogyria and focal nonconvulsive status epilepticus where high epileptogenicity was responsible for progressive and severe cognitive dysfunction. Nonconvulsive status epilepticus in epileptic encephalopathy with unilateral multilobar polymicrogyria has not been reported previously.

Human Imaging: Adult

Abstract 1 Bassel W. Abou-Khalil, 1 Christine Dong, 1 Muhammad Al-Kaylani, 1 Amir Arain, 1 Pradumna Singh, 1 Michael J. McLean, and 1 Subramaniam Sriram ( 1 Neurology, Vanderbilt University, Nashville, TN ) Rationale: A confident diagnosis of nonconvulsive status epilepticus confirmed with EEG is essential for appropriate patient management. However, EEG may not be diagnostic in some patients, particularly when the seizure activity is focal or deep. We encountered five patients with ictal aphasia (4) or ictal amnesia (1), in whom the diagnosis of nonconvulsive status epilepticus could not be made on EEG, but was demonstrated with focal hypermetabolism on positron emission tomography with fluorodeoxyglucose (FDG PET). Methods: We obtained FDG PET scans in 5 patients with suspected ictal aphasia or ictal amnesia who did not have demonstration of ictal activity on EEG. Positive scans were repeated after resolution of symptoms in 3 patients. We reviewed clinical, EEG and imaging data, as well as outcome with treatment. Results: Four patients presented with subacute onset of aphasia and one with amnesia, without structural abnormalities on MRI. The EEG showed left temporal irregular delta activity but no clear ictal pattern in three patients with aphasia, and other nonspecific abnormalities in the two remaining patients. All patients had a focus of hypermetabolism on FDG PET. This was left frontotemporal in the patients with ictal aphasia and bilateral hippocampal in the patient with amnesia. Intravenous benzodiazepines in three patients produced transient response. Symptoms and PET hypermetabolism gradually resolved with anti-epileptic drug therapy. Conclusions: FDG PET scan should be considered as a diagnostic tool in patients with suspected focal nonconvulsive status epilepticus who fail to show clear evidence of ictal activity on EEG.

Diagnostic and localizing value of ictal SPECT in patients with nonconvulsive status epilepticus

In this study, we evaluate the diagnostic and localizing value of SPECT in three patients with nonconvulsive status epilepticus (NCSE). Our results indicate that ictal/subtraction ictal SPECT is a useful complementary noninvasive diagnostic test in patients with focal NCSE. This is especially the case when the EEG findings are inconclusive and for patients in whom surgical treatment is being considered.

Focal nonconvulsive status epilepticus associated to PLEDs and intense focal hyperemia in an AIDS patient

Focal nonconvulsive status epilepticus associated to PLEDs and intense focal hyperemia in an AIDS patient

Focal nonconvulsive status epilepticus associated to PLEDs and intense focal hyperemia in an AIDS patient

Purpose: Periodic lateralised epileptiform discharges (PLEDs) can be seen associated to nonconvulsive status epilepticus (NCSE), although their pathophysiological meaning remains questionable. Functional neuroimaging has suggested that, in this setting, PLEDs may indeed be an ictal pattern. In this report we describe perfusional changes in a patient with AIDS, PLEDs and NCSE. Methods: A 37-year-old man with AIDS, cryptococcosis and recurrent epileptic seizures was admitted. After initial treatment, he remained comatose, and had MRI and serial EEG recordings performed. Technetium-99m-ethyl cysteinate dimer (99mTc-ECD) SPECT scans were also obtained, before and after continuous benzodiazepine infusion. Results: EEG disclosed PLEDs over the right fronto-polar region while MRI revealed meningeal thickening and scattered unspecific findings. SPECT revealed marked focal hyperperfusion overlapping the areas with PLEDs, both resolved after continuous midazolam infusion and clinical improvement. Conclusions: This report demonstrates association of PLEDs, NCSE, and focal hyperperfusion on SPECT, additionally supporting the concept of PLEDs as an ictal pattern. Considering that status epilepticus may eventually not be detected by conventional approaches alone, we advocate the use of functional neuroimaging to assess suspected patients with impaired consciousness.