Diagnosis, Etiology, and Treatment of Nonconvulsive Status Epilepticus, a Semiological Oriented Review.

BACKGROUND: Nonconvulsive status epilepticus (NCSE) defines a prolonged electrographic seizure activity resulting in nonconvulsive symptoms. Semiology is a crucial element in diagnosis, etiological evaluation, and treatment plan of NCSE. It includes mostly generalized myoclonic status (GMS), focal simple motor status (FSMS), and dyscognitive status (DS). REVIEW SUMMARY: This review aims to guide clinicians in diagnosis, etiological evaluation, and treatment of patients with NCSE based on semiological presentation. CONCLUSIONS: Diagnosis of GMS and FSMS is based mainly on semiology, whereas DS often requires EEG for differential diagnosis with nonepileptic events. GMS and FSMS etiological investigation may be readily prioritized based on semiological type, whereas DS requires EEG for further classification in psychomotor status and absence status. Choice of appropriate treatment is dictated by the semiological presentation, EEG findings, and etiology. Surgery and other interventions including electroconvulsive therapy and vagal nerve stimulation should be considered in patients refractory to medical treatment.

Acute symptomatic seizures: a clinically oriented review.

BACKGROUND: Acute symptomatic seizures are seizures closely related to neurological or systemic insults and represent about 40% of all first seizures. Diagnosis may be difficult to perform due to the subjectivity involved in recognizing the severity of insult needed to provoke epileptic seizures or in determining a clear temporal relationship. Appropriate therapeutic management, risk of developing epilepsy, and mortality depend largely on the underlying disorder. REVIEW SUMMARY: A general overview regarding definition, epidemiology, and causes of acute symptomatic seizures is provided. Diagnosis, frequency, risk factors, pathophysiology, therapeutic management, and prognosis of acute symptomatic seizures related to each insult individually are discussed. The insults considered are: acute stroke, traumatic brain injury, central nervous system infections, medication, alcohol and illicit drugs, electrolytic and metabolic disorders, anoxic encephalopathy, eclampsia, reversible posterior leukoencephalopathy, and limbic encephalitis. CONCLUSIONS: Operational diagnostic criteria have been recommended by the International League Against Epilepsy and are based on temporal relationship, severity, and type of insult. Antiepileptic drug prophylaxis is recommended in severe head trauma, preeclampsia, and possibly high-risk subarachnoid or intracranial hemorrhage. It is crucial to rapidly identify all insults possibly involved, treat underlying diseases, revert corrigible factors, and in case of central nervous system involvement, use antiepileptic drugs during the acute period. Risk of epilepsy is increased in patients with neurological insults but not with metabolic disorders. Some refractory epilepsies in adults, mostly epilepsy due to hippocampal sclerosis, are preceded by acute symptomatic seizures related to selected insults occurring at a specific time. Mortality rate is globally increased.

Diversity in anti-N-methyl-D-aspartate receptor encephalitis: case-based evidence.

Antibodies against N-methyl-D-aspartate receptor (NMDAR) are identified in the form of immune-mediated encephalitis in which typical manifestations include neuropsychiatric symptoms, seizures, abnormal movements, dysautonomia and hypoventilation. The authors report two cases of anti-NMDAR encephalitis with different presentations and patterns of progression. The first patient presented with status epilepticus and later developed psychosis, pyramidal signs and diffuse encephalopathy. The second patient presented with acute psychosis followed a week later by seizures, dystonia, rigidity, oromandibular dyskinesias and dysautonomia. Possible mechanisms responsible for the clinical manifestations of this disease are discussed in light of recently described additional clinical and laboratory findings.

Quantitative movement analysis differentiates focal seizures characterized by automatisms.

The analysis of epileptic seizures is typically performed by visual inspection, limited by interrater variation. Our aim was to differentiate seizures characterized by automatisms with an objective, quantitative movement analysis. In part 1 of this study we found parameters (extent and speed of movement of the wrist and trunk) separating seizures with predominant proximal (hyperkinetic, n=10) and distal (automotor, n=10) limb automatisms (P<0.002). For each movement parameter we used the lowest value recorded for a hyperkinetic seizure in part 1 as the cutoff parameter in part 2 on a consecutive sample of 100 motor seizures. As in part 1, the difference between hyperkinetic and non-hyperkinetic seizures was highly significant (<0.001). When all movement parameters were above the threshold, a hyperkinetic seizure was identified with a probability of 80.8%, but the probability for a non-hyperkinetic seizure to have all parameters above the threshold was only 0.02%.

Frontal lobe epilepsy.

About one-quarter of patients with refractory focal epilepsies have frontal lobe epilepsy (FLE). The typical seizure semiology for FLE includes unilateral clonic, tonic asymmetric or hypermotor seizures. Interictal electroencephalograms (EEG) usually reveal interictal epileptiform discharges and rhythmical midline theta, which has localizing value. The usefulness of ictal EEG recordings is limited by frequent muscle artifacts in motor seizures and because a large portion of the frontal lobe cortex is "hidden" to scalp electrodes. Ictal single photon emission CT and positron emission tomography are able to localize FLE in about one-third of patients only. A pre-surgical evaluation should include, whenever possible, a subclassification of FLE as dorsolateral frontal, mesial frontal or basal frontal lobe epilepsy to allow a minimal cortical resection. A review of the typical findings of seizure semiology, interictal and ictal EEG regarding the different FLE subtypes is given. Etiology, medical treatment and surgery are also discussed.

Epidural and foramen-ovale electrodes in the diagnostic evaluation of patients considered for epilepsy surgery.

PURPOSE: To evaluate the clinical utility of epidural and foramen-ovale recordings and associated morbidity in the pre-surgical evaluation of epilepsy. METHODS: We retrospectively analysed 59 epilepsy patients, who underwent recordings with epidural (n = 59) and foramen-ovale electrodes (n = 46) as part of their pre-surgical evaluation between 1990-1999. The epidural and foramen-ovale evaluation was based on the results of the non-invasive EEG-video recordings in patients, in whom non-invasive evaluation failed to localise seizure onset (75%, 44 patients) or where EEG, and imaging studies were discrepant (25%, 15 patients) but allowed a testable hypothesis on the seizure onset zone. RESULTS: Most patients (n = 57) were evaluated between 1990-1994. Only two patients were evaluated later. The results of the epidural (n = 559) and foramen-ovale (n = 83) electrode recordings allowed us to proceed to resective epilepsy surgery in 31% (n = 18) and to exclude further invasive evaluation in 15% (n = 9) of the patients. In 49% (n = 29) of the patients the results guided further invasive recordings using subdural and/or depth electrodes. For only three patients no additional information was gained by the electrode recordings. Temporary morbidity included local infection (epidural; n = 1) and facial pain (foramen ovale; n = 1) but no permanent complication occurred. DISCUSSION: Epidural and foramen-ovale electrodes have almost been abandoned in recent years, most likely because of the improvement of neuroimaging techniques such as MRI, PET and ictal SPECT. However, in selected patients, epidural electrodes and foramen-ovale electrodes are either useful as a measure to avoid invasive evaluation or serve to guide invasive evaluation.

Refractory epilepsy: a clinically oriented review.

About one third of patients with newly diagnosed epilepsy do not achieve seizure control despite medical therapy and should be assessed in detail to confirm the diagnosis, to determine the epilepsy syndrome and to plan treatment strategy. Refractory epilepsy is established when there is inadequate seizure control despite using potentially effective antiepileptic drugs (AEDs) at tolerable levels for 1-2 years, and excluding nonepileptic events and poor compliance. An overview of patient management in everyday clinical practice is given. Risk factors for refractoriness include (1) generalized epilepsy with lesions; (2) focal epilepsy with hippocampal sclerosis, cortical dysplasia or hemorrhages; (3) early epilepsy onset; (4) high seizure frequency; (5) absence of response to the first 2 AEDs; (6) high frequency of interictal spikes, and (7) multifocal spikes. The efficacy of surgery ranges from curative (resection) to palliative (vagus nerve stimulation, callosotomy, multiple subpial transections) depending on the epilepsy syndrome and etiology. Using a new antiepileptic drug benefits about one third of patients. Refractoriness is constitutive in most patients and shows a progressive or remission-relapse course in others. As the transporter and target hypotheses do not entirely explain refractoriness, other hypotheses are emerging. New treatments under investigation are described.

Interictal rhythmical midline theta differentiates frontal from temporal lobe epilepsies.

PURPOSE: We evaluated the role of interictal rhythmical midline theta (RMT) in the identification of frontal lobe epilepsy (FLE) and its differentiation from temporal lobe epilepsy (TLE) and nonepileptic controls. METHODS: We included 162 individuals in the study: 54 FLE patients, 54 TLE patients, and 54 nonepileptic controls. Continuous electroencephalographic (EEG)-video monitoring was performed in all individuals. Interictal RMT was included only if it occurred during definite awake states. RMT associated with drowsiness or mental activation and ictal RMT was excluded. RESULTS: We identified RMT significantly more frequently in FLE patients (48.1%, 26 of 54) than in TLE patients (3.7%, 2 of 54) (p < 0.01), and not in the control group. The average frequency was 6 Hz (range 5-7 Hz), and the average RMT bursts lasted 8 s (3-12 s). Interestingly, all mesial FLE patients (n = 4) (as established by invasive EEG recordings) showed RMT, whereas this was less frequently the case in the other FLE patients (44%, 22 of 50) (p = 0.03). Thirteen of our 54 patients with FLE (24%) did not have any interictal epileptiform discharges (IEDs), but RMT was observed in the majority of these patients (62%, 8 of 13). CONCLUSION: Interictal RMT is common and has a localizing value in patients with FLE, provided that conditions such as drowsiness and mental activation as confounding factors for RMT are excluded. RMT should be included in the evaluation of patients considered for resective epilepsy surgery.

Probable acute disseminated encephalomyelitis due to Haemophilus influenzae meningitis.

We report the case of a 17-year-old male on long-term steroid therapy for minimal lesion glomerulopathy who, after an upper respiratory infection, presented with Haemophilus influenzae type b meningitis. Twenty-four hours later he developed depression of consciousness which progressed to coma and left hemiparesis. Brain magnetic resonance imaging (MRI) revealed multiple lesions (hyperintense on T2 and slightly hypointense on Tl) involving mainly white matter suggestive of inflammation. MRI features were compatible with acute disseminated encephalomyelitis (ADEM), although a differential diagnosis included cerebritis or vasculitis, secondary to bacterial meningitis. The patient was treated with high-dose steroids which resulted in a gradual improvement followed by complete clinical recovery. We propose a diagnosis of ADEM was the best diagnosis because of the radiological features and response to steroids. The occurrence of ADEM associated with acute meningitis, however rare, represents an important diagnostic challenge for the clinician.

From juvenile parkinsonism to encephalitis lethargica, a new phenotype of post-streptococcal disorders: case report.

We report the case of a 16-year-old boy presented with a mild akinetic-rigid parkinsonism shortly after a post-streptococcal infection. After stopping corticoids, he had a rapid neurological deterioration to a fatal encephalitis lethargica-like syndrome. Serum analysis demonstrated consistently elevated anti-streptolysin-O. This case illustrates a new severe phenotype in the spectrum of the post-streptococcal disorders. This etiology should be considered in the differential diagnosis of a movement disorder with a rapid detrimental evolution.

Ictal SPECT in Sturge-Weber syndrome.

We report on a patient with right-sided Sturge-Weber syndrome (SWS), in whom earlier functional hemispherectomy failed. Subtraction of ictal and interictal single-photon-emission-computed-tomography (SPECT) superimposed on individual MRI showed a right fronto-orbital hyperperfusion, with a left-sided EEG seizure pattern. Ictal SPECT supported our assumption that right frontal originated seizure pattern propagated to left hemisphere via the remaining right frontal bridge. Right orbito-frontal resection and disconnection from corpus callosum resulted in seizure freedom.

IgE-mediated hypersensitivity after ibuprofen administration.

Although many immunoglobulin-related drug sensitivities have been described, there is a paucity of reports regarding IgE-related drug sensitivities. Here we describe a case of a patient who demonstrated IgE-mediated sensitivity to ibuprofen.

[Reverse crossed cerebellar diaschisis]. / Diaschisis cerebelosa cruzada reversa.

Cerebral Magnetic Resonance imaging in acute postictal period is performed to exclude structural processes that can be responsible for the epileptic activity. Sometimes, the findings are the result of the epileptic activity, and not the cause reflecting the pathophysiologic changes during epileptic activity. In this paper we describe a patient with status epilepticus who has developed hemicerebellar involvement contralateral to a frontal epileptogenic focus. This phenomenon of Reverse Crossed Cerebellar Diaschisis is rare and has been describe only in Single Photon Emission Computed Tomography (SPECT).

[Wallerian degeneration after stroke: a new prognostic factor?]. / Degenerescência Walleriana pós-enfarte: um novo factor prognóstico?

Wallerian degeneration (WD) after ischemic stroke has been associated to persistent motor impairment, but signal intensity changes on conventional magnetic resonance imaging (MRI) are generally not detected until four weeks after the event. We report a 54 year old male patient, referred to our hospital for sudden-onset left hemiparesis. Cerebral CT showed right fronto-parietal infarct (middle cerebral artery stroke). We performed two CT control, which revealed no haemorrhagic transformation. MRI, obtained 13 days after the onset, demonstrated the infarct, mainly subcortical, extending throughout fronto-temporo-parietal areas and restricted diffusion in the ipsilateral corticospinal tract. In conclusion, WD is apparent on diffusion-weighted imaging within two weeks of stroke, allowing a better prognostic evaluation of recovery. The abnormal signal should not be misinterpreted as new ischaemic lesions.