The trigemino-cervical reflex in patients with trigeminal neuralgia

OBJECTIVES: To investigate the central trigeminal system in idiopathic trigeminal neuralgia (TN). MATERIALS AND METHODS: Short latency responses can be recorded in sternocleidomastoid (SCM) muscles after stimulation of the trigeminal nerve (trigemino-cervical reflex). This brainstem reflex was investigated in 40 healthy subjects and in 17 patients suffering from idiopathic TN before and after therapy for 2 months with carbamazepin. RESULTS: Before therapy, six patients presented abnormalities of SCM responses on the painful side, six patients with bilateral abnormalities, and five patients with normal responses. A significant variation in the responses after therapy was found only in the patients with unilateral abnormalities: these patients and the patients with normal reflexes before therapy also had a good response to the therapy with significant pain relief. CONCLUSIONS: Our findings suggest that the trigemino-cervical reflex could be useful in the clinical assessment of TN prior to instituting non-surgical treatment. The bilateral location of the abnormalities in some patients seems to point to a centrally located dysfunction; therefore, this study supports the idea that mechanisms in the central nervous system may play an important role in the pathophysiology of trigeminal neuralgic pain.     

The trigemino-cervical reflex in patients with trigeminal neuralgia

Abstract

Objectives: To investigate the central trigeminal system in idiopathic trigeminal neuralgia (TN).

Materials and methods: Short latency responses can be recorded in sternocleidomastoid (SCM) muscles after stimulation of the trigeminal nerve (trigemino-cervical reflex). This brainstem reflex was investigated in 40 healthy subjects and in 17 patients suffering from idiopathic TN before and after therapy for 2 months with carbamazepin.

Results: Before therapy, six patients presented abnormalities of SCM responses on the painful side, six patients with bilateral abnormalities, and five patients with normal responses. A significant variation in the responses after therapy was found only in the patients with unilateral abnormalities: these patients and the patients with normal reflexes before therapy also had a good response to the therapy with significant pain relief.

Conclusions: Our findings suggest that the trigemino-cervical reflex could be useful in the clinical assessment of TN prior to instituting non-surgical treatment. The bilateral location of the abnormalities in some patients seems to point to a centrally located dysfunction; therefore, this study supports the idea that mechanisms in the central nervous system may play an important role in the pathophysiology of trigeminal neuralgic pain.     

瞬目反射对原发性和继发性三叉神经痛的鉴别诊断价值

目的研究瞬目反射(BR)对原发性和继发性三叉神经痛的鉴别诊断价值。方法采用神经电生理检查方法,对23例原发性三叉神经痛及7例继发性三叉神经痛患者进行BR检测,记录潜伏期及波幅的变化,并与正常对照组比较。结果原发性三叉神经痛组与正常对照组间BR各波潜伏期及波幅差异无统计学意义(P>0.05);继发性三叉神经痛组BR各波潜伏期较原发性三叉神经痛组和正常对照组显著延长(均P<0.01)。结论BR对鉴别原发性和继发性三叉神经痛具有临床应用价值。     

Familial trigeminal neuralgia

Trigeminal neuralgia in its classic form is usually an isolated disease that occurs in sporadic fashion, but familial cases have been described. We report the case of a 45-year-old man who presented with left V2 trigeminal neuralgia. The neurological examination was normal and imaging and laboratory investigations were non-contributive to the etiological work-up. Carbamazepine gave excellent symptomatic relief. During patient evaluation, we became aware of a clustering of trigeminal neuralgia in four other family members over three generations. Familial trigeminal neuralgia has been expounded on in fewer than 30 reports in the literature. Our cases and the literature review suggest an autosomal dominant transmission. The clinical features of familial trigeminal neuralgia are described and pathophysiological implications of this genetic clustering discussed.     

Familial trigeminal neuralgia

Familial trigeminal neuralgia is infrequent. A report of a couple and their son being afflicted by this malady is presented. The clinical features, radiological findings and surgical management are discussed and literature reviewed.     

Pathogenesis of trigeminal neuralgia

<正>To the editor,I read with interest the article,Differences in individual susceptibility affect the development of trigeminal neuralgiaby Duransoy et al.(2013).The authors have analyzed the possible pathogenesis of trigeminal neuralgia,with illustrative case examples.They have drawn very important conclusions,which may have implications in     

Drug therapy of trigeminal neuralgia

Trigeminal neuralgia is a chronic pain syndrome of still unestablished origin. Its diagnosis depends on clinical grounds. Drug therapy initially helps a great majority of patients. The choice of drugs is quite large, but truly effective compounds with a tolerable side effect profile remain few. Carbamazepine (or oxcarbazepine) and lamotrigine appear to be the most effective, followed by baclofen. Several patients require further nonpharmacological treatment for which no evidence-based recommendation is possible. In the future, neuromodulation may be brought to bear, as in other chronic pain syndromes.     

Diagnostic accuracy of electrodiagnostic testing in the evaluation of weakness

Electrodiagnostic testing is often used in the evaluation of patients presenting with weakness, but the diagnostic accuracy of the test in this setting is unknown. We prospectively identified 100 patients presenting to our electromyography (EMG) laboratory with the chief complaint of weakness, and compared their referring diagnosis with the electrophysiological diagnosis reached after electrodiagnostic testing. We reviewed each patient's medical record 9 months after EMG to yield a final diagnosis. Electrodiagnostic testing led to a single diagnosis in 79% of the cases; in 31%, this diagnosis was unsuspected by the referring clinician. Adequate follow-up was available for 79% of the patients. The electrodiagnostic testing resulted in a single, correct diagnosis in 73% of the patients and provided more than one possible diagnosis, one of which was correct, in an additional 18%, for an overall diagnostic accuracy of 91% in this group of patients presenting with weakness.     

Altered cutaneous sensation in trigeminal neuralgia

Noninvasive quantitative somatosensory tests were used to measure sensory perception thresholds on the faces of 26 patients with idiopathic trigeminal neuralgia. The affected divisions were determined by the presence of trigger zones. Elevations of thresholds of sensations subserved by both large- and small-diameter fibers were found both in the affected and in the unaffected adjacent divisions when compared with the healthy side. The findings are interpreted as further evidence of combined peripheral and central pathologic conditions in idiopathic trigeminal neuralgia.     

三维时间飞跃法MRA及图像后处理技术对血管压迫性三叉神经痛的诊断价值

目的　探讨三维时间飞跃法磁共振血管成像 (3D TOFMRA)及其后处理技术 (MPR)对血管压迫性三叉神经痛的诊断价值。方法　两名神经放射科医师盲法分析 38例临床诊断为三叉神经痛患者的 3D TOFMRA基础图像及MPR图像。结果　 (1) 38例三叉神经痛患者中 ,MRI诊断为血管接触或压迫 31例 ,其中有症状侧血管接触或压迫 2 6例。症状侧与影像上三叉神经存在血管接触或压迫有显著相关 (P <0 0 0 5 )。(2 ) 14例以三叉神经第 2支分布区域疼痛为主要症状的患者中 ,85 .7% (12例 )血管压迫神经的中间部位 ;10例以三叉神经第 3支分布区域疼痛为主要症状的患者中 ,70 % (7例 )血管压迫神经的侧方 (P <0 0 0 5 )。结论　 3D TOFMRA及MPR可清晰地显示三叉神经脑池段与毗临血管的关系 ,血管压迫神经的部位与疼痛的区域有一定的相关性