[Singular clinical form of intramedullary cavity revealed by a loss of proprioceptive sensation in the upper limbs].

A 47-year-old woman developed a progressive sensory deficit of the upper limbs. She lost perception of joint position, vibratory sense, skin-writing and stereognosis. Repeated tests by several examiners, up to 10 years after the onset, demonstrated normal pain and temperature sensation. The right hypoglossal nerve was involved at a late stage of the disease. CT and MRI showed an intramedullary cavity from C1 to T7. Somato-sensory evoked potentials from stimulation of the median nerves confirmed the bilateral impairment of the lemniscal pathways.