No abstract

A review of the magnetic resonance (MR) images of 365 patients with acquired immunodeficiency syndrome (AIDS) revealed that 112 (31%) had signal abnormalities confined to the white matter. Four patterns were observed: (a) diffuse: widespread involvement of a large area; (b) patchy: localized involvement with ill-defined margins; (c) focal: well-defined areas of involvement; and (d) punctate: small foci less than 1 cm in diameter. Clinical or pathologic findings were available in 60 of the 112 patients and were correlated with the white matter patterns seen on MR images. The diffuse pattern correlated with AIDS dementia complex (ADC), which was the most common clinical diagnosis. Patchy or punctate lesions may be seen with ADC but are less common. Focal white matter lesions were not seen in patients with ADC but were seen in all six patients with progressive multifocal leukoencephalopathy, in both patients with lymphoma, and in one patient with toxoplasmosis. The authors conclude that white matter lesions are are common in AIDS and are often secondary to direct infection of the brain with human immunodeficiency virus, which causes the ADC and usually produces a diffuse white matter pattern. Biopsy is probably not indicated in these patients. Focal white matter lesions suggest a focal infection or tumor, and biopsy may be warranted.

The clinical findings and computerized tomography (CT) brain scans of 45 patients with supratentorial intracerebral hematomas were evaluated to determine the effect of hematoma location on the clinical course and outcome of the disease. The lesions were frontal in 18 patients, temporal or temporoparietal in 17, and parieto-occipital in 10. No patient with a frontal or parieto-occipital hematoma had clinical signs of transtentorial herniation at admission or subsequently, whereas seven (41%) of those with temporal or temporoparietal lesions had signs of herniation (p less than 0.05); three of these seven patients had an abnormal mental status, ipsilateral anisocoria, and lateralizing motor findings at admission, and four developed these signs within 12 hours after admission, necessitating urgent surgical intervention. The mean volume of the lesions estimated from the CT scans was similar in the three groups (frontal 47 +/- 28 cc; parieto-occipital 53 +/- 26 cc; temporal/temporoparietal 41 +/- 21 cc). None of the six patients with temporal or temporoparietal hematomas smaller than 30 cc had signs of tentorial herniation, compared with seven (64%) of 11 patients with larger hematomas (p less than 0.05); in six of these seven cases, the hematoma was caused by head injury. Patients with a temporal or temporoparietal hematoma had a worse outcome than those in the other two groups, and no patient with signs of tentorial herniation had a good outcome. Patients with temporal or temporoparietal hematomas appear to be at greater risk of brain-stem compression, especially if the lesion is larger than 30 cc and caused by head injury, than are those with hematomas in other sites. In such cases, prompt surgical intervention should be considered.

Recently, Ropper reported that horizontal brain shift caused by acute unilateral mass lesions correlated closely with consciousness, and suggested that recovery of consciousness was unlikely to occur after surgical evacuation if the shift was insufficient to explain the observed diminution of consciousness. The authors have sought to confirm the correlation of pineal shift with level of consciousness and to assess the prognostic value of brain shift measurements in a prospective study. Forty-six patients (19 with subdural hematoma, 14 with intracerebral hematoma, and 13 with epidural hematoma) were accrued to the study group consecutively. A correlation was found between a decrease in the level of consciousness and a significant increase in the mean lateral brain displacement at the pineal gland (from 3.8 to 7.0 mm) and septum (5.4 to 12.2 mm). When outcome was examined in patients who were stuporous or comatose on admission, a significant increase in septal shift was found among patients with a poor outcome, but there was no significant relationship between outcome and degree of pineal or aqueductal shift. A poor outcome was more likely with effacement of both perimesencephalic cisterns or the ipsilateral cistern, but not the contralateral cistern, although this difference did not reach statistical significance. These results do not substantiate the value of brain shift as an independent prognostic factor after evacuation of an acute unilateral mass lesion. The decision to operate and the determination of prognosis should be based rather on established criteria such as the clinical examination, age of the patient, and the mechanism of injury.