Randomized controlled pilot study of vigabatrin versus carbamazepine monotherapy in newly diagnosed patients with epilepsy: an interim report.

At present, 34 patients aged 15 to 63 years with newly diagnosed epilepsy have been randomly assigned to vigabatrin (n = 17) or carbamazepine (n = 17). Evaluation of clinical data, neuropsychological assessment, quantitative spectral electroencephalogram (EEG), and somatosensory- and visual-evoked potentials at baseline and after a 3 months' maintenance phase are presented for 12 patients on vigabatrin and for 11 patients on carbamazepine. Among these patients, retention rate in the maintenance phase of the study is 75% for vigabatrin patients (two noncompliant patients and one nonresponder dropped out) followed up for a mean of 11 months (range, 5 to 16 months). The retention rate for carbamazepine is 100% for the 11 patients, followed up for a mean of 9 months (range, 3 to 17 months). Patients receiving vigabatrin showed significant improvements in sustained concentration and tasks requiring flexible mental processing after the 3-month maintenance period, compared to baseline. In the carbamazepine group, there was improvement only in delayed list recall, and in contrast, errors in visuomotor tasks requiring processing increased significantly. Patients on carbamazepine demonstrated slowed occipital mean frequencies, but vigabatrin treatment was not associated with any significant quantitative EEG changes. Significant prolongation of somatosensory-evoked potential N19 latencies was seen with both carbamazepine and vigabatrin.

Cholinesterase activities in the autonomic nervous system of rabbits with experimental allergic neuritis: a biochemical study.

Utilizing a colorimetric method with acetylthiocholine iodide (AThCh) as substrate and eserine and ethopropazine as inhibitors, the activities of AThCh-splitting enzymes, acetylcholinesterase (AChE) and non-specific esterase (psi ChE) were determined in different structures of the autonomic nervous system (ANS) from the left and from the right sides of rabbits with experimental allergic neuritis (EAN) and controls. The total activity of AThCh-splitting enzymes showed a highly significant decrease in the ganglion nodosum and in the ganglia of the thoracal and abdominal paravertebral sympathetic chain in rabbits with clinical symptoms of ANS-involvement. Lesser but still significant changes were found in EAN-rabbits with motor symptoms but without ANS symptoms. No definite changes could be found in the superior cervical ganglia, the cervical sympathetic trunk or the interganglionic portions of the abdominal and thoracal paravertebral sympathetic chains. In samples with decreased total enzyme activities, both AChE and psi ChE appeared to decrease to approximately the same extent. This study demonstrates that the activities of AThCh-splitting enzymes are decreased in EAN in parts of ANS innervating the heart, abdominal and pelvic organs, and suggests that enzyme activities not derived from the myelin sheath may be involved in the pathogenesis of this demyelinating disease.

Involvement of autonomic nervous system in experimental allergic neuritis. A light- and electron-microscopic study.

The affection of the sympathetic and parasympathetic structures of the peripheral nervous system in rabbits with experimental allergic neuritis (EAN) was demonstrated light- and electron-microscopically. The general characteristics of the microscopic findings were qualitatively similar to those previously established in the somatic nervous system, but they were less extensive. The neuronal perikarya and the axons in the autonomic nervous system (ANS) were mostly normal. Occasionally, cytoplasmic vacuoles in a few nodose ganglion neurons and some degenerating axons were seen. Other than myelin derived antigens could be operating in whole-nerve induced EAN, since inflammatory cells also infiltrated target tissue areas devoid of myelinated nerve fibers. The presence of numerous plasma cells in the target tissue suggests that local antibody formation may contribute to the destructive process. Our results establish that the ANS is frequently affected in EAN, especially in the more severe forms. Thus EAN was proved to be also in this respect a useful model for the human disease Guillain-Barré syndrome, which likewise is often complicated by autonomic dysfunctions.

Electromyographic and nerve conduction findings in a patient with neuromyotonia, normocalcemic tetany and small-cell lung cancer.

A 57-year-old man with neuromyotonia and normocalcemic tetany as probable paraneoplastic symptoms of small-cell lung cancer was examined neurophysiologically. In EMG, spontaneous action potential generation was demonstrated in peripheral motor axons. There were also time-locked high-frequency discharges after some voluntarily activated motor unit potentials. After electrical stimulation of motor axons, the M-response as well as spinal F-response or H-reflex was often followed by a sequence of oscillating potentials which could last several hundred msec. There was no evident peripheral polyneuropathy. Tetany subsided when carbamazepine therapy was started. The only striking abnormality in extensive laboratory studies was an increase in the plasma noradrenaline value.