Evoked Potentials in Trigeminal Neuralgia

Abstract

Trigeminal evoked potentials and sensory thresholds in response to maxillary gum stimulation were obtained in patients with a complaint of unilateral face pain. The patients and the volunteer, normal control groups had undergone no prior surgical or other procedures involving cranial or cervical structures. For statistical purposes, patient data were analyzed with respect to the diagnostic classification of classical trigeminal neuralgia, atypical trigeminal neuralgia, or other face pain states in which the pain extended beyond the trigeminal nerve distribution. Latencies of trigeminal evoked potentials on the affected side were significantly increased (compared to normal control group responses) in patients with classical but not in those with atypical trigeminal neuralgia nor other face pain syndromes. All three patient groups had statistically significant threshold elevations on the affected side compared to the unaffected side. A high level of significance for this test was obtained for the classical trigeminal neuralgia group. Ratings for patients based upon the preoperative electrophysiological findings were highly correlated with long term results of microvascular decompression of the 5th nerve root for classical, but not for atypical trigeminal neuralgia patients. These results support the view that atypical and classical trigeminal neuralgia symptom complexes are caused by different types of physiological dysfunction and that classical trigeminal neuralgia is associated with compression of the trigeminal nerve root. It was suggested that the rating system may be a useful, objective, clinical adjunct in evaluating patients with classical trigeminal neuralgia.

Tongue somatosensory evoked potentials in microvascular decompression treated trigeminal neuralgia

“…12 However, normal trigeminal evoked potentials can be found even in the presence of a sensory deficit, emphasizing the problem with sensory examination in TN (especially hyperesthesia), which is very subjective. 13 Considering this; tSSEP could represent a fast and safe way of determining trigeminal afferent function in a laboratory setting.…”

Use of sensory and motor action potentials to identify the position of trigeminal nerve divisions for radiofrequency thermocoagulation

“…These factors may lead to insufficient or confused verbal responses followed by imprecise lesion localization or even therapeutic failure. 2 Moreover, because the cooperation of patients is essential to this procedure, continuous general anesthesia is not recommended, and therefore discomfort and stress associated with the procedure may increase.…”

“…In an effort to improve accuracy, previous studies have been performed to investigate the application of orthodromically elicited potentials of the trigeminal nerve, 2,5,12,14 which were helpful for electrode localization during surgery. However, the results were contradictory and tedious applications were needed.…”

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“…São encontradas anormalidades eletromiográficas da musculatura temporal e do masseter, especialmente em casos de neuralgia sintomática, mesmo quando o exame clínico é normal 43,53,60,76,77,89 . O estudo eletrofisiológico do reflexo do piscamento e do reflexo mentoniano 11,43,60 e potencial evocado somatossensitivo podem sofrer alterações em muitos doentes com dor facial 11,12,95 . O exame do líquido cerebrospinal é utilizado para o diagnóstico de processos expansivos intracranianos intra e extra-axiais 5,15,61,63 .…”

“…Com aperfeiçoamentos, a técnica passou a ser indicada, também, no tratamento de outras condições, como neuralgia decorrente de esclerose múltipla, neuralgia secundária a processos expansivos e neuralgia atípica da face. Nesses últimos casos, entretanto, os resultados foram menos satisfatórios que os observados em doentes com neuralgia essencial do trigêmeo 10,11,18,20,36,68,80,116 . Durante a execução do presente trabalho, a punção do forame oval foi realizada com agulhas de biópsia hepática ou agulhas 14 G usadas para o implante de eletrodos epidurais.…”