[Primary mesencephalic hemorrhage: report of four cases]

Spontaneous intracerebral hemorrhage rarely occurs in the mesencephalon (midbrain), though thalamic or pontine hemorrhage may extend into that location. The neurologic manifestations and outcome in patients with primary mesencephalic hemorrhage (PMH) are different from those with thalamic or pontine hemorrhage. We report 4 patients (2 men and 2 women) with nontraumatic and non-neoplastic hemorrhages confined to the mesencephalon. One young patient, a 37-year-old woman, had no detectable risk factors for stroke, and her cerebral angiogram was normal. The other 3 elderly patients (73-85 years of age) all had a history of hypertension. The neurologic manifestations of patients with PMH are characterized by disturbance of ocular movements and cerebellar signs. Two patients with tegmental hematoma showed Claude's syndrome, i.e., ipsilateral oculomotor palsy and contralateral cerebellar signs. One patient with a small central midbrain hematoma showed bilateral oculomotor palsy. Another patient with a relatively large central midbrain hematoma presented with bilateral ptosis, bilateral internuclear ophthalmoplegia, upward gaze palsy, and bilateral cerebellar signs. The prognosis after conservative treatment for our patients with PMH was good.