Herta Flor1, Dirk Rasche2, Ariyan Pirayesh Islamian3, Claudia Rolko1, Pinar Yilmaz1, Marc Ruppolt4, H Holger Capelle3, Volker Tronnier2, Joachim K Krauss3. 1. Department of Clinical and Cognitive Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany. 2. Department of Neurosurgery, University of Lubeck, Lubeck, Germany. 3. Department of Neurosurgery Medical School Hannover, Hannover, Germany. 4. Department of Neurosurgery, Klinikum Eilbeck, Hamburg, Germany.
Abstract
BACKGROUND: Trigeminal neuralgia (TN) is characterized by paroxysmal pain attacks affecting the somatosensory distributions of the trigeminal nerve. It is thought to be associated with a neurovascular conflict most frequently, but pathomechanisms have not been fully elucidated. In general, no sensory deficit is found in routine clinical examination. There is limited data available, however, showing subtle subclinical sensory deficits upon extensive testing. OBJECTIVE: We used quantitative sensory testing (QST) to detect abnormalities in sensory processing in patients with TN by comparing the affected and non-affected nerve branches with their contralateral counterparts and by comparing the results of the patients with those of controls. STUDY DESIGN: Observational study. SETTING: University Hospital, Departments of Neurosurgery, Institute for Cognitive and Clinical Neuroscience. METHODS: QST was conducted on 48 patients with idiopathic TN and 27 controls matched for age and gender using the standardized protocol of the German Neuropathic Pain Network. Stimulations were performed bilaterally in the distribution of the trigeminal branches. The patients had no prior invasive treatment, and medications at the time of examination were noted. RESULTS: In patients with TN deficits in warm and cold sensory detection thresholds in the affected and also the non-affected nerve branches were found. Tactile sensation thresholds were elevated in the involved nerve branches compared to the contralateral side. LIMITATIONS: More data are needed on the correlation of such findings with the length of history of TN and with changes of the morphology of the trigeminal nerve. CONCLUSIONS: QST shows subtle sensory abnormalities in patients with TN despite not being detected in routine clinical examination. Our data may provide a basis for further research on the development of TN and also on improvement after treatment. KEY WORDS: Quantitative sensory testing, trigeminal neuralgia, facial pain, neuropathic pain, microvascular decompression, cranial nerve.
BACKGROUND:Trigeminal neuralgia (TN) is characterized by paroxysmal pain attacks affecting the somatosensory distributions of the trigeminal nerve. It is thought to be associated with a neurovascular conflict most frequently, but pathomechanisms have not been fully elucidated. In general, no sensory deficit is found in routine clinical examination. There is limited data available, however, showing subtle subclinical sensory deficits upon extensive testing. OBJECTIVE: We used quantitative sensory testing (QST) to detect abnormalities in sensory processing in patients with TN by comparing the affected and non-affected nerve branches with their contralateral counterparts and by comparing the results of the patients with those of controls. STUDY DESIGN: Observational study. SETTING: University Hospital, Departments of Neurosurgery, Institute for Cognitive and Clinical Neuroscience. METHODS: QST was conducted on 48 patients with idiopathic TN and 27 controls matched for age and gender using the standardized protocol of the German Neuropathic Pain Network. Stimulations were performed bilaterally in the distribution of the trigeminal branches. The patients had no prior invasive treatment, and medications at the time of examination were noted. RESULTS: In patients with TN deficits in warm and cold sensory detection thresholds in the affected and also the non-affected nerve branches were found. Tactile sensation thresholds were elevated in the involved nerve branches compared to the contralateral side. LIMITATIONS: More data are needed on the correlation of such findings with the length of history of TN and with changes of the morphology of the trigeminal nerve. CONCLUSIONS: QST shows subtle sensory abnormalities in patients with TN despite not being detected in routine clinical examination. Our data may provide a basis for further research on the development of TN and also on improvement after treatment. KEY WORDS: Quantitative sensory testing, trigeminal neuralgia, facial pain, neuropathic pain, microvascular decompression, cranial nerve.
Authors: Luciana Mendonça Barbosa; Valquíria Aparecida da Silva; Antônia Lilian de Lima Rodrigues; Diego Toledo Reis Mendes Fernandes; Rogério Adas Ayres de Oliveira; Ricardo Galhardoni; Lin Tchia Yeng; Jefferson Rosi Junior; Adriana Bastos Conforto; Leandro Tavares Lucato; Marcelo Delboni Lemos; Roland Peyron; Luis Garcia-Larrea; Manoel Jacobsen Teixeira; Daniel Ciampi de Andrade Journal: Brain Commun Date: 2022-04-05