Ictal brain hemodynamics in the epileptic focus caused by a brain tumor using functional magnetic resonance imaging (fMRI).
Using functional magnetic resonance imaging (fMRI) we were able to observe, in detail, ictal brain hemodynamics during epileptic seizure caused by a brain tumor. A 53-year-old man was experencing partial motor seizures of the left side of his face and neck. In a brain MR image a mass lesion was found in the subcortical area of the right frontal lobe. We found focal spikes in his right hemisphere, though dominantly in C4 and T4 regions. fMRI investigations were carried out at 1.5 T (GE Signa Horizon) using gradient-echo echo-planar neuroimaging. We were able to perform the ictal examination twice. The activated regions were focalized and clearly found only on the lateral side of the tumor base. The region was in agreement with the epileptic focus examined using an electrocorticogram (ECOG). The signal intensity in the seizure focus rapidly increased 30 seconds before the convulsion was observed. After the end of the convulsion it also took 30 seconds to restore the signal intensity to the baseline value. fMRI is a very useful tool for various studies such as the identification of the epileptic focus, the mechanism of epileptic seizure, and so on. (+info)
Periodic lateralized epileptiform discharges in influenza B-associated encephalopathy.
An 18-year-old woman presented with coma, hemicomvulsions, and transient periodic lateralized epileptiform discharges (PLEDs). Serological tests were positive for influenza B, and cerebrospinal fluid PCR for herpes simplex virus DNA was negative. Magnetic resonance imaging later showed abnormal signal intensity in the temporal lobe ipsilateral to the PLEDs. Influenza-associated encephalopathy may cause hemiconvulsions and PLEDs, and can mimic herpes simplex encephalitis. (+info)
Low dose and slow titration of topiramate as adjunctive therapy in refractory partial epilepsies: a multicentre open clinical trial.
PURPOSE: A multicentre open clinical trial was conducted to evaluate the clinical usefulness of a slower titration of topiramate (TPM) to 300 mg /day as adjunctive therapy for medically intractable partial epilepsies. METHODS: Nineteen centres participated in the trial. Study patients had to have had two or more seizures per 4 weeks whilst taking maximum tolerated doses of one but not more than two anti-epileptic drugs. The starting dose of TPM was 25 mg /day and the dose was increased weekly by 25 mg /day until 100 mg /day was reached. Thereafter TPM was increased by 50 mg /day weekly up to the target dose of 300 mg /day, which was followed by an 8 week maintenance phase. Seizure outcomes were measured by intention-to-treat analysis (ITTA). RESULTS: Two hundred and thirteen patients entered the study. Median seizure frequency reduction rate was 44.8%, responder rate was 47.6%, and seizure free rate was 9.0%. These results were comparable to that of TPM 600 mg /day in our previous controlled trial. In subgroup analysis, seizure free rate was higher in those patients with a lower baseline seizure frequency rate. Seventeen patients (8.0%) were prematurely withdrawn from the study due to adverse events (AE) or lack of effect. One or more AEs were reported in 22% of patients, with dizziness being the most frequent AE. Other AEs occurred in less than 5% of patients. CONCLUSION: TPM 300 mg /day was effective and in conjunction with a slower dose-titration, markedly reduced the incidence of AEs, compared with previous study. (+info)
Metabolic consequences of a novel missense mutation of the mtDNA CO I gene.
We have identified a novel heteroplasmic C6489A missense mutation in the mitochondrial DNA (mtDNA) CO I gene encoding the cytochrome c oxidase (COX) subunit I in a 17-year-old girl with epilepsia partialis continua. This point mutation leads to an exchange of the highly conserved Leu196 to Ileu196. Muscle biopsy showed in single fibers decreased COX activity and lowered binding of COX antibodies, indicating decreased stability of the mutated enzyme. The analysis of blood mtDNA revealed about 30% mutant mtDNA in the patients blood but about 90% mutant mtDNA in the blood of two non-affected family members. Quantitative analysis of the mutation gene dose effect on COX activity on single muscle fiber level revealed a very high threshold-a COX deficiency was observed only in fibers containing >95% mutant mtDNA. In apparent contrast to this high mutation gene dose threshold, in vivo investigations of mitochondrial function in saponin-permeabilized muscle fibers of the index patient containing approximately 90% mutated mtDNA showed decreased maximal rates of respiration and an increased sensitivity of fiber respiration to cyanide. This is due to a 2-fold increase of COX flux control on muscle fiber respiration and a 30% decrease of COX metabolic threshold, supporting the concept of tight COX control of oxidative phosphorylation in skeletal muscle. (+info)
Functional connectivity in human cortical motor system: a cortico-cortical evoked potential study.
In order to understand the complex functional organization of the motor system, it is essential to know the anatomical and functional connectivity among individual motor areas. Clinically, knowledge of these cortico-cortical connections is important to understand the rapid spread of epileptic discharges through the network underlying ictal motor manifestation. In humans, however, knowledge of neuronal in vivo connectivity has been limited. We recently reported a new method, 'cortico-cortical evoked potential (CCEP)', to electrically track the cortico-cortical connections by stimulating a part of the brain through subdural electrodes and recording the cortical evoked potentials that emanate from a distant region of the cortex via neuronal projections. We applied the CCEP methodology to investigate in vivo cortico-cortical connections between the lateral motor cortex [LMCx; sensorimotor (SM) and lateral premotor areas] and the medial motor cortex [MMCx; supplementary motor area proper (SMA), pre-SMA and foot SM]. Seven patients with intractable partial epilepsy were studied. These patients had chronic implantation of subdural electrodes covering part of the lateral and medial frontal areas. As a part of the routine pre-surgical evaluation, comprehensive cortical mapping was performed by electrical stimulation of the subdural electrodes, and the precise localization of the subdural electrodes was defined by MRI co-registration. Single-pulse electrical stimuli were delivered to MMCx (7 patients) and LMCx (4), and CCEPs time-locked to the stimuli were recorded by averaging electrocorticograms from LMCx and MMCx, respectively. Short-latency CCEPs were observed when stimulating MMCx and recording from LMCx (mean latency: 21.6 ms, range: 9-47 ms) and vice versa when stimulating LMCx and recording from MMCx (mean latency: 29.4 ms, range: 11-57 ms). In terms of the location of these stimulus sites and CCEP responses along the rostrocaudal axis, regression analysis revealed a consistent correlation between the sites of stimulation and maximum CCEP for stimulation of both MMCx and LMCx. Functionally, stimulation of the positive motor areas in MMCx elicited CCEPs at the somatotopically homologous regions in LMCx (71%). The same findings were observed in MMCx (82%) upon stimulation of LMCx. In four subjects in whom bi-directional connectivity was investigated by stimulating both MMCx and LMCx, reciprocality was observed in the majority of connections (78-94%). In conclusion, the present study demonstrated a human motor cortico-cortical network connecting (i) anatomically homologous areas of LMCx and MMCx along the rostrocaudal cognitive-motor gradient; and (ii) somatotopically homologous regions in LMCx and MMCx in a reciprocal manner. (+info)
Repetitive transcranial magnetic stimulation decreases the number of seizures in patients with focal neocortical epilepsy.
A challenging review of childhood incontinence: rare complications of dysfunctional elimination syndrome in an epileptic boy.
A multidisciplinary approach is mandatory in defining the cause and directing the treatment of childhood urinary incontinence. Both pediatricians and pediatric urologists should carefully evaluate a child with incontinence for possible overlapping etiologies, before labeling him or her as a refractory case. We report an epileptic boy with dysfunctional elimination syndrome (DES) with associated rare complications of giggle incontinence and idiopathic urethritis, proving the need for a good voiding diary, patient history and structured symptom scores. (+info)
The subcortical hidden side of focal motor seizures: evidence from micro-recordings and local field potentials.