Biomedical subjects
Publications and source records attributed to L A Alvarez.
Severe cases of Sydenham chorea are still difficult to manage because optimal therapy has not been found. In this report severe chorea responded to valproic acid therapy after trials with diazepam and haloperidol had failed. The literature is reviewed and the possible mechanism of action of valproate in this movement disorder is discussed. Valproic acid is proposed as an effective treatment for severe cases of Sydenham chorea.
Differentiating seizures from pseudoseizures frequently is challenging in very young children manifesting repetitive, stereotypic behavior. Using video electroencephalographic recording, we evaluated 60 patients, younger than 10 years of age, with episodic signs and symptoms believed to be seizures despite repeatedly normal routine electroencephalograms. Nine patients (15%) had simple partial and atypical absence seizures. Twenty-four patients (40%) had pseudoseizures presenting as rhythmic movements or staring. Pseudoseizure frequency was greater than the frequency of true seizures; brief staring episodes were common. Motor pseudoseizures usually were of longer duration than true seizures and could be brought on with verbal encouragement. Furthermore, the stereotypic motor presentations were quite different from those of true motor seizures but were difficult to recognize from historic, clinical, and routine electroencephalographic data. Symptomatic patients can be clinically diagnosed by analyzing confirmed episodes with video electroencephalography.
The relation between hyperventilation (HV)-induced high-amplitude rhythmical slowing (HIHARS) and altered responsiveness without generalized spike and wave activity has not been clearly defined. To test whether altered responsiveness is a nonspecific physiologic response rather than a symptom of generalized epilepsy, we assessed verbal recall ability and motor response testing in 12 healthy nonepileptic children (mean age 9.6 years). Both tasks were administered as a baseline before HV, during HV but before onset of EEG slowing, and during HIHARS. Verbal recall and motor responsiveness remained unchanged during baseline and HV before onset of slowing. During HIHARS, all children exhibited impaired verbal recall (p < 0.005) and 8 of 12 failed to respond to repeated auditory clicks (p < 0.005). Our findings indicate that in a normal setting, responsiveness may be impaired during HV in healthy nonepileptic children.
INTRODUCTION: Vagal nerve stimulation is the latest therapeutic modality for the treatment of epilepsy. It consists of a lead implanted in the left vagal nerve which is connected to a subcutaneous stimulator implanted in the left axillary or pectorial region. DEVELOPMENT: The stimulator is programmed to intermittently stimulate the vagal nerve throughout the day and a magnet also allows the patient to control the stimulation from the outside. This treatment has been used in patients with intractable partial seizures who are not candidates for epilepsy surgery. The results reported have varied but in general the procedure appears promising with at least 50% of the implanted having over 50% improvement in their seizure frequency and many having complete control without significant side effects. CONCLUSION: Further review of the results are still needed to fully determine the true value of this treatment and to identify the subgroups of patients which will benefit the most.
The authors describe the use of intraoperative US for directing placement of depth electrodes for the localization of seizure foci prior to temporal lobectomy. They used this technique in seven patients (six undergoing temporal and one frontal resection), and encountered no complications.