HYPOXIC BRAIN-LESIONS - CT AND MRI ASPECT S - REPORT ON 20 CASES

Brain lesions following hypoxic-ischaemic injuries are known from auto psy studies, but their appearance in live patients has been only occas ionally described, and only sporadic reports have been published on th eir CT and MRI images. Over a 2-year period (1991-93) we studied the c linical, MRI and CT features in 20 patients shortly after a severe hyp oxia. Clinical examination showed motor extrapyramidal signs in 13 cas es and coma in 7 cases. MR with inversion recovery (IR) and T2-weighte d spin echo (SE) sequences was performed in 17 patients and CT in 15. Bilateral lesions were found in 11 cases, but in 13 of them CT was nor mal. Radiological lesions were always symmetrical and bilateral, locat ed in the pallidum in 10 cases, the striatum in 4 cases and the thalam us in 2 cases. Additional white matter lesions were present in only 4 MRI examinations. No relationship was found between the mechanism of h ypoxia and the severity of clinical signs. The course of the clinical signs was correlated with the presence of radiological lesions. In com atous patients there was a relation between parkinsonism and abnormali ties of basal ganglia. None of the patients who had perinatal asphyxia had radiological lesions. The presence of pallidal or striatal confir med the hypoxic origin of neurological symptoms, especially in patient s with parkinsonism. MRI, particularly in IR sequences, makes it possi ble to detect small lesions in basal ganglia after hypoxic injuries.