Clinical HistoryA 31-year-old, previously healthy man had a sudden onset of sharp interscapular pain, followed by rapidly evolving quadriparesis associated with paresthesias and pain radiating to the anterior part of the chest. Over the next several hours he had difficulty urinating and required catheterization. Three weeks prior to hospitalization, he was treated with erythromycin for an upper respiratory tract infection but had otherwise been well. There was no history of trauma or homosexuality. He did not smoke, drink, or use drugs. On examination, the patient was afebrile with normal vital signs. The general physical examination was only remarkable for moderate obesity. Neurologically, the patient was alert and attentive, with a normal mental status. Cranial nerves were intact and there was no evidence of Homer's syndrome. He exhibited a weak cough but had adequate respiratory function. Motor examination revealed mild weakness of both deltoids and biceps, no function of the triceps or muscles of the forearms and hands, and a flaccid paraplegia. Tendon reflexes were present only in the biceps and were absent in the triceps, patellae, and ankles. Plantar responses were absent. There was no anal wink or superficial abdominal reflexes, and the anal sphincter was flaccid. Sensory examination revealed a level of decreased sensation on the trunk at approximately C-4, below which, including the perianal and inguinal regions, pinprick and temperature sensations were diminished. However, both vibration and joint position sense as well as light touch were preserved in both arms and legs.Laboratory Data: Results of routine chemistries, complete blood cell count, urinalysis, electrocardiography, and chest radiograph were all within normal limits. The sedimentation rate was 17 mm/hr, and antinuclear antibody and rapid plasma reagin test results were negative. Serum protein electrophoresis, cold agglutinins, and Lyme titers were negative or normal. Cerebrospinal fluid analysis revealed 2 white blood cells per cubic millimeter, normal protein and glucose levels, and no oligoclonal bands. Myelography and postmyelographic computed tomography (CT) of the cervical region demonstrated normal findings. Magnetic resonance images (MRis) of the cervical spinal area on admission appeared normal. Cranial MRI and chest CT also showed normal findings. Median nerve somatosensory-evoked potentials revealed 156 Copyright©