A 41 year old woman with subacute onset of moderate and progressive right hemiparesis showed on the MRI a unilateral white matter lesion on the left temporoparietal region and a small lesion on the right frontal region. The CSF was normal. Because possible diagnosis of tumor or abscess, the patient underwent a cerebral biopsy. The histological result was of brain tissue with demyelination and reactive changes. The stains for viral etiology were negative.
multiple sclerosis; MRI; demyelination