FRONTAL-LOBE CHANGES AFTER SEVERE DIFFUSE CLOSED-HEAD INJURY IN CHILDREN - A VOLUMETRIC STUDY OF MAGNETIC-RESONANCE-IMAGING

IN VIEW OF the pathophysiology and biomechanics of severe closed head injury (CHI) in children, we postulated that the frontal lobes sustain diffuse injury, even in the absence of focal brain lesions detected b y magnetic resonance imaging (MRI). This study quantitated the morphol ogical effects of CHI on the frontal lobes in children who sustained h ead trauma of varying severity. The MRI findings of 14 children who ha d sustained severe CHIs (Glasgow Coma Scale score of less than or equa l to 8) were compared with the findings in a matched group of 14 child ren having sustained mild head injuries (Glasgow Coma Scale score of 1 3-15). The patients ranged in age from 5 to 15 years at the time of th eir MRIs, which were acquired at least 3 months postinjury. MRI findin gs revealed no focal areas of abnormal signal in the frontal lobes. Vo lumetric analysis disclosed that the total prefrontal cerebrospinal fl uid increased and the gray matter volume decreased in the patients wit h severe CHI, relative to the mildly injured comparison group. Gray ma tter volume was also reduced in the orbitofrontal and dorsolateral reg ions of the brains of children with severe CHI, relative to the childr en who sustained mild head trauma. These volumetric findings indicate that prefrontal tissue loss occurs after severe CHI in children, even in the absence of focal brain lesions in this area. Nearly two-thirds of the children who sustained severe CHIs were moderately disabled aft er an average postinjury interval of 3 years or more, whereas 12 of th e 14 patients with mild CHIs attained a good recovery (2 were moderate ly disabled) by the time of study. Although this initial study of brai n morphometry after CHI in children was not designed to isolate the co ntribution of frontal lobe damage to residual disability, further rese arch involving a larger sample is in progress to address this issue.