Voltage-gated potassium channels autoantibodies in a child with rasmussen encephalitis.

Rasmussen encephalitis (RE) is a severe epileptic and inflammatory encephalopathy of unknown etiology, responsible for focal neurological signs and cognitive decline. The current leading hypothesis suggests a sequence of immune reactions induced by an indeterminate factor. This sequence is thought to be responsible for the production of autoantibody-mediated central nervous system degeneration. However, these autoantibodies are not specific to the disease and not all patients present with them. We report the case of a 4-year-old girl suffering from RE displaying some atypical features such as fast evolution and seizures of left parietal onset refractory to several antiepileptics, intravenous immunoglobulins, and corticosteroids. Serum autoantibodies directed against voltage-gated potassium channels (VGKC) were evidenced at 739 pM, a finding never previously reported in children. This screening was performed because of an increased signal in the temporolimbic areas on brain magnetic resonance imaging, which was similar to what is observed during limbic encephalitis. The patient experienced epilepsia partialis continua with progressive right hemiplegia and aphasia. She underwent left hemispherotomy at the age of 5.5 years after which she became seizure free with great cognitive improvement. First described in adults, VGKC autoantibodies have been recently described in children with various neurological manifestations. The implication of VGKC autoantibodies in RE is a new observation and opens up new physiopathological and therapeutic avenues of investigation.

Place of magistral preparations to continue the treatment if the drug is commercially stopped worldwide? A case report of a 10-year-old child with subacute sclerosing panencephalitis (SSPE) requiring inosiplex.

Subacute sclerosing panencephalitis (SSPE) is a late-onset and fatal viral disease caused by persistent infection of the central nervous system by measles virus (MeV). We present the case of a 10-year-old child from South Asia affected by SSPE, stabilized with a combination of intrathecal interferon-α2b (INF-α2b) injections and oral inosiplex and how we continued the treatment when inosiplex was commercially stopped worldwide.

Neural dynamics of mindfulness meditation and hypnosis explored with intracranial EEG: A feasibility study.

PURPOSE: Intracranial electroencephalography (iEEG) offers a unique window on brain dynamics with excellent temporal and spatial resolution and is less prone to recording artefacts than surface EEG. This study used a within-subject design to explore the feasibility to compare iEEG data during mind wandering, mindfulness meditation and hypnosis. RESULTS: Three patients who had iEEG for clinical monitoring and who were new to mindfulness meditation and hypnosis were able to enter these states. We found non-specific and wide-spread amplitude modulations. Data-driven connectivity analysis revealed widespread connectivity patterns that were common across the three conditions. These were predominant in the low frequencies (delta, theta and alpha) and characterised by positively correlated activity. Connectivity patterns that were unique to the three conditions predominated in the gamma band, one third of the correlations in these patterns were negative. CONCLUSIONS: This study is the first to support the feasibility of a direct comparison of the neural correlates of mindfulness meditation and hypnosis using iEEG. These modulations may reflect the complex interplay between different known brain networks, and warrant further functional investigations in particular in the gamma band.

Cannabis use, ischemic stroke, and multifocal intracranial vasoconstriction: a prospective study in 48 consecutive young patients.

BACKGROUND AND PURPOSE: Our objective was to evaluate the relationship between cannabis use and ischemic stroke in a young adult population. METHODS: Forty-eight consecutive young patients admitted for acute ischemic stroke participated in the study. First-line screening was performed, including blood tests, cardiovascular investigations, and urine analysis for cannabinoids. If no etiology was found, 3D rotational angiography and cerebrospinal fluid analysis were performed. A control was planned through neurovascular imaging within 3 to 6 months. RESULTS: In this series, there was multifocal intracranial stenosis associated with cannabis use in 21% (n=10). CONCLUSIONS: Multifocal angiopathy associated with cannabis consumption could be an important cause of ischemic stroke in young people.

De novo epileptic confusion in the elderly: a 1-year prospective study.

PURPOSE: Nonconvulsive status epilepticus (NCSE) is clinically difficult to diagnose, especially in old patients without epilepsy, and requires electroencephalography (EEG) for diagnosis. Its incidence among elderly patients with confusion of unknown origin (CUO) remains undetermined. METHODS: A 1-year prospective study was conducted in patients aged 60 years or older, for whom EEG was requested because of confusion considered to be of unknown origin after initial clinical, biologic, and imaging investigations. Diagnosis criteria included a validated clinical assessment scale to confirm confusion. RESULTS: Of 44 patients with confirmed CUO, 7 presented with de novo NCSE. NCSE population had a mean age of 76 years (range, 60-97 years). No statistically significant differences were found between NCSE patients and others for age, drugs, presence of myoclonia, eyelid myoclonia, tachycardia, or agitation. In contrast, an acute onset (<24 h), gender (100% female among NCSE patients), and lack of clinical response to simple commands were significantly associated with NCSE. No differences between the two groups were evidenced for mortality and morbidity (length of hospitalization, social outcome, and so on). DISCUSSION: Almost 16% of patients aged 60 or older with confusion of unknown origin had NCSE, according to this first prospective study. Female patients with rapid onset (<24 h) of symptoms and lack of response to simple commands were at a higher risk of presenting with NCSE.

How Long Should Routine EEG Be Recorded to Get Relevant Information?

OBJECTIVE: The optimal duration of routine EEG (rEEG) has not been determined on a clinical basis. This study aims to determine the time required to obtain relevant information during rEEG with respect to the clinical request. METHOD: All rEEGs performed over 3 months in unselected patients older than 14 years in an academic hospital were analyzed retrospectively. The latency required to obtain relevant information was determined for each rEEG by 2 independent readers blinded to the clinical data. EEG final diagnoses and latencies were analyzed with respect to the main clinical requests: subacute cognitive impairment, spells, transient focal neurologic manifestation or patients referred by epileptologists. RESULTS: From 430 rEEGs performed in the targeted period, 364 were analyzed: 92% of the pathological rEEGs were provided within the first 10 minutes of recording. Slowing background activity was diagnosed from the beginning, whereas interictal epileptiform discharges were recorded over time. Moreover, the time elapsed to demonstrate a pattern differed significantly in the clinical groups: in patients with subacute cognitive impairment, EEG abnormalities appeared within the first 10 minutes, whereas in the other groups, data could be provided over time. CONCLUSION: Patients with subacute cognitive impairment differed from those in the other groups significantly in the elapsed time required to obtain relevant information during rEEG, suggesting that 10-minute EEG recordings could be sufficient, arguing in favor of individualized rEEG. However, this conclusion does not apply to intensive care unit patients.

Recommendations for the use of electroencephalography and evoked potentials in comatose patients.

Predicting the outcome of a comatose or poorly responsive patient is a major issue for intensive care unit teams, in order to give the most accurate information to the family and to choose the best therapeutic option. However, determining the level of cortical activity in patients with disorders of consciousness is a real challenge. Reliable criteria are required to help clinicians in the decision-making process, especially in the acute phase of coma. In this paper, we propose recommendations for recording and interpreting electroencephalography and evoked potentials in comatose patients based on the literature and the clinical experience of a group of neurophysiologists trained in the management of comatose patients. We propose methodological guidelines and discuss prognostic value of each test as well as the limitations concerning recording and interpretation. Recommendations for the strategy and timing of neurophysiological assessments are also proposed according to various clinical situations.

Towards a definition of the "practical" epileptogenic zone: a case of epilepsy with dual pathology.

Presurgical evaluation for patients with drug-resistant epilepsy requires the definition of various zones that have a variable spatial relationship with the epileptogenic zone. All the available methods to directly measure the actual seizure-onset zone and to define "the minimum amount of cortical tissue that must be resected to produce seizure-freedom" have significant limitations. We report on the case of a patient with dual pathology (hippocampal sclerosis and a post-traumatic scar) and discuss the contribution of the various presurgical investigations that led to surgery and seizure-freedom.

Low-frequency photoparoxysmal response in adults: an early clue to diagnosis.

Intermittent photic stimulation is performed during an EEG to evoke photoparoxysmal response. When they appear triggered by low-frequency stimulation in children, they are suggestive of rare diagnosis, that is, neuronal ceroid lipofuscinosis. Among adults, their significance is less well understood. Low-frequency (<5 Hz) intermittent photic stimulation was performed over a period of 5 years during adult standard EEG. This retrospective study included all patients exhibiting low-frequency photoparoxysmal response. Five cases were identified. Three of them presented with active epilepsy (two progressive myoclonus epilepsy, one unclassifiable), two had visual deficiency, and three had dementia. The etiologies were MELAS (two), Creutzfeldt-Jakob disease (one), Kufs disease (one), and remained undetermined for one patient. In all patients, low-frequency photoparoxysmal response was observed years or months before the final diagnoses have been reached. Low-frequency photoparoxysmal response, classically associated with childhood progressive myoclonus epilepsy, seems to have a wider etiological spectrum in adult population. Moreover, this neurophysiological feature could be present before the final diagnosis in most cases. Systematically testing low frequencies during intermittent photic stimulation even during adult EEG seems warranted, particularly in a context of severe progressive neurologic deterioration.

Optimizing therapy of seizures in patients with renal or hepatic dysfunction.

Patients with epilepsy may suffer from renal or hepatic diseases that interfere with their antiepileptic drug (AED) treatment. Furthermore, such diseases may themselves cause seizures. Reduced renal function and hypoalbuminemia lead to accumulation of renally excreted AEDs, such as gabapentin, vigabatrin, topiramate, levetiracetam, and phenytoin. Valproate, lamotrigine, and benzodiazepines are less affected. Low protein-bound AEDs are extensively removed by hemodialysis and supplemental doses are required for dialysis patients. Uremia and related conditions, including intracranial hemorrhage, glucose and electrolyte imbalances, and concomitant drug use, can cause seizures, as can dialysis encephalopathy, primary cerebral lymphoma, fungal infections, and immunosuppressant toxicity in renal transplant recipients. Hepatic dysfunction reduces enzymatic metabolism of AEDs and causes hypoalbuminemia. Gabapentin, topiramate, and levetiracetam are preferred in these conditions, whereas conversely valproate and felbamate are potentially hepatotoxic and should be avoided. Seizures related to hepatic encephalopathy are controlled by oral lactulose or neomycin. Porphyria sufferers may benefit from gabapentin, oxcarbazepine, or levetiracetam. Seizures in Wilson's disease may derive from d-penicillamine-induced pyridoxine deficiency. Effective treatment of seizures in renal and hepatic diseases requires attention to changes in AED pharmacokinetics and adequate care of the underlying illnesses. Monitoring of free drug concentrations is a valuable aid to therapy.