[Trigeminal neuropathy and connective tissue diseases]

Connective tissue diseases are a rare and poorly understood etiology of trigeminal neuropathy. In a retrospective multicentric study covering 12 years. 12 cases were identified in the archives of the Departments of Neurology, Rheumatology and Internal Medicine: 4 were associated with progressive systemic sclerosis. 4 with mixed connective tissue diseases and 4 with Sjögren's syndrome. In 9 of the cases, the neuropathy led to the diagnosis of connective tissue disease. Trigeminal neuropathy usually developed during the evolution of the connective-tissue disease but, in 3 cases, it preceded other clinical signs. As a rule, the connective tissue disease was relatively inactive when the trigeminal nerve was involved. The neuropathy was usually unilateral (9 times), localized to the inferior branch(es) of the trigeminal and manifested itself by an isolated sensation of cutaneous numbness associated with paresthesias. Only one patient had mixed motor and sensory involvement. The topography of the lesions (peripheral, truncal, radicular or central nuclear) remains unknown in most cases, however, electromyographic study of the blinking reflex in 2 patients confirmed peripheral neuropathy in both of them. Corticotherapy had only a minor effect: neuralgia was rare and carbamazepine was ineffective. The pathogenicity of trigeminal involvement is discussed and these observations are compared to the 151 cases reported in the literature.