[MRI findings in patients with acute autonomic and sensory neuropathy].

Acute autonomic and sensory neuropathy (AASN), characterized by acute onset of extensive autonomic dysfunction and severe sensory deficits, was first described by Colan et al. (1978). We present two female patients with AASN in whom magnetic resonance imaging (MRI) confirmed such findings in the posterior column of the spinal cord. One patient was a 44-year-old woman who developed an upper respiratory tract infection followed in 2 weeks by numbness of the limbs and gait disturbance. There was orthostatic hypotension with syncope, paretic ileus, anhidrosis and urinary retention. There was a loss of sensation over the entire body, including the face, and deep tendon reflexes were generally absent. Neurophysiologic studies showed that sensory nerve action potentials and SSEPs were not evoked in the nerves examined. Sural nerve biopsy demonstrated severe axonal degeneration of the myelinated and unmyelinated fibers. Our second patient, a 27-year-old woman, exhibited similar clinical and laboratory features. The autonomic dysfunction in both patients improved gradually without drug treatment, but the sensory deficits--predominantly a loss of deep sensation--persisted for several years. In both patients, MRI revealed the T2*-weighted high intensity area in the fasciculus gracilis of the posterior column of the spinal cord. Such high intensity areas were present in all spinal segments. The severe and persistent sensory disturbance in these patients may have been caused by a lesion of the posterior column of the spinal cord following the involvement of the dorsal root ganglion cells, or ganglioneuronopathy, as demonstrated by MRI.