A Chistiakov | PubMed Health

PubMed1995

[Microvascular decompression of the trigeminal nerve: electrophysiological changes].

In a 67-year-old woman with trigeminal neuralgia, pressure on the trigeminal nerve of vascular bundle and arachnoidal adhesions was relieved by microsurgery. Short-latency, brainstem, trigeminal evoked-potentials were continuously recorded throughout the operation. The initial response was characterized by prolonged latency, low amplitude and distorted shape. Immediately after decompression the response attained normal latency, amplitude and shape. Pain disappeared within less than 24 hours. Power spectrum analysis showed wide frequency range in the initial evoked potentials, consistent with desynchronization of the afferent impulses. The range of frequencies was reduced to normal as soon as the trigeminal nerve was decompressed.

Aged↗

PubMed1995

[Short-latency, brainstem, trigeminal evoked-potentials].

Short-latency, evoked-potentials were recorded from over the scalp in response to electrical stimulation of the upper lip, using the Microshev 4000 equipment (Microshev Co., Efrat). Normative data were obtained from 35 normal volunteers. The brain-stem, trigeminal evoked-potentials (BTEP) consisted of 4 distinct, well-reproduced waves evoked in less than 10 msec. The waves, named after their respective latencies, are thought to be generated in the preganglionic trigeminal nerve (T1), the postganglionic nerve entry zone (T2), in the trigeminal nucleus (T3) and the upper brainstem (T5). BTEP was recorded in nearly 200 patients suffering from various lesions in the peripheral trigeminal parts, tumors affecting the brainstem (before, during and after surgery) and in varying degrees of post-traumatic coma. BTEP proved to be a reliable tool for evaluating the brainstem trigeminal system; changes in its pattern reliably reflected altered activity of that system. It can be used for diagnosis as well as for intraoperative monitoring of brainstem function.

Brain Diseases↗