Isolated symptomatic stenosis of the middle cerebral artery in younger adults. A clinical and ultrasonic follow-up study of eight patients.

We studied 8 symptomatic patients aged 32-56 years with isolated stenosis of the middle cerebral artery who had TIAs or minor strokes. Angiography showed MCA stenosis in the M1 segment in 7 patients, and proximal M1 occlusion that later recanalized with persistent stenosis in 1 patient, without evidence of more widespread atherosclerotic disease. A potential cardiac source of embolism was detected in only 2 patients with mitral valve prolapse. During follow-up for 39-82 months, no further ischemic events occurred, and transcranial Doppler showed unchanged or decreased stenosis in 6 patients. We conclude that isolated MCA stenosis in younger patients may be a unique pathologic entity with a benign long-term course, although previous embolism with partial recanalization appears possible in some patients.