[Sensory trigeminal neuropathy in systemic diseases: 4 cases with study of the trigeminofacial reflex].

Isolated trigeminal nerve affections can occur during the course of various connective tissue diseases, particularly scleroderma and mixed connective tissue lesions. Four cases are reported: a patient with systemic scleroderma, one with atrophic polychondritis, one with Gougerot-Sjögren's disease and one with atypical and frustes connective tissue lesions. The mechanisms of onset and lesional location in these neuropathies are poorly understood. A blink reflex study by electrical stimulation of the supraorbital nerve was carried out in these 4 patients to determine the site of lesions. Response was normal in 1 case suggesting a lesion of a distinct branch of the supraorbital nerve. In 2 cases the anomalies of the early response were strongly suggestive of a peripheral, truncal or radicular lesion. In the last patient the early response was normal and latencies in tardive responses of the stimulated side were in favor of a central lesion of the spinal root or spinal nucleus of the trigeminal nerve. Clinical characteristics of some reported cases of neuropathy of trigeminal nerve also appear to point to a central lesion.