The trigemino-cervical reflex in patients with trigeminal neuralgia.
OBJECTIVE
To investigate the central trigeminal system in idiopathic trigeminal neuralgia (TN).


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.
Nardone
Raffaele
R
Department of Neurology, F.Tappeiner' Hospital, Via Rossini, 5, 39012 Merano, Italy. raffaele.nardone@asbmeran-o.it
Matullo
Massimo F
MF
Tezzon
Frediano
F
D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D002220:Carbamazepine / Q000627:therapeutic use; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D009334:Neck Muscles / Q000187:drug effects / Q000294:innervation / Q000503:physiopathology*; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D012018:Reflex / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D020433:Trigeminal Nerve Diseases / Q000503:physiopathology*; D014277:Trigeminal Neuralgia / Q000188:drug therapy / Q000503:physiopathology*
D000927:Anticonvulsants; D002220:Carbamazepine