[Sarcoidosis: the presentation of a case with clinical features limited to the nervous system]

Neurological pathology as the initial form of sarcoidosis is exceptional. Neurosarcoidosis represents 5% of all cases. Central nervous system involvement is more frequent in the acute forms of this illness, whilst myositis and peripheral neuropathy are more common in chronic sarcoidosis.

A 60 year old woman presented with peripheral facial diplegia, diminished visual acuity and bilateral papilloedema, dysarthria and unsteady gait with left lateropulsion and paresia and dysesthesia of the distal parts of the limbs. X-ray and laboratory findings were normal. Gammography with Gallium 67 citrate showed mediastimal adenopathy. Neurographic study was compatible with mixed polyneuropathy and lumbar puncture showed aseptic meningitis. The diagnosis of neurosarcoidosis was confirmed by histopathological study of the skin and sural nerve.

When the presenting features of sarcoidosis are neurological, as in this case, diagnosis is difficult and pathology studies showing the presence of non-caseous granulomas are essential. Biopsy of the sural nerve may be very useful. Although the pathogenesis of sarcoid neuropathology is not completely clear, finding non-caseous granulomas associated with vasculitis in the nerve biopsy indicates that both disease processes may be involved in the peripheral nerve lesion.