[Pseudotumoral medullary syndrome manifesting a probably beginning multiple sclerosis. Clinical, radiological and neuropathological correlations].

A 19-y old sportsman was admitted because he complained of ascending paresthesia since two weeks, muscular strength diminution in both arms, then respiratory difficulties without fever. Clinical examination confirmed an asymmetric bilateral pyramidal syndrome affecting the four limbs, a hyposensitive level up to C5, without meningeal symptoms. MRI detected a widening of the cervical (C2-C5) spinal cord, with gadolinium enhancement. CSF demonstrated lymphocytic pleocytosis and total protein of 530 mg/l with an oligoclonal IgG pattern. With a diagnosis of multiple sclerosis, a corticoid therapy was started but without clinical improvement. Six weeks later, a new MRI revealed an increased enlargement of the cervical spinal cord suggesting a tumoral process. No tumor could be detected at neurosurgery. Biopsy specimen (from C3-C4) demonstrated an inflammatory demyelinating disease with astrocytic hypertrophy. Electron microscopy confirmed the active demyelinating disorder with persistently denuded axons. Several macrophages were observed, but no lymphocytic invasion. Astrocytes were prominent in some areas with "en plaque" gliosis. MRI failed to discover any other demyelinating lesions. Further clinical evaluation was inconspicuous, the patient regaining full activities after 6 months. MRI after 9 months demonstrated no spinal cord lesion. This observation contributes to suggest the influence of the blood-brain barrier breakdown on the occurrence of clinical and radiological signs of new lesions in suspected multiple sclerosis.