Harvey S. Levin

Discourse after Closed Head Injury in Young Children

This study examined narrative discourse in 23 children, ages 6 to 8 years, who sustained a severe closed head injury (CHI) at least 1 year prior to assessment. Narratives were analyzed at multiple levels using language and information structure measures. Results revealed significant discourse impairments in the CHI group on all measures of information structure, whereas differences in the linguistic domain failed to reach significance. In addition, effects of age at injury and lateralization of lesion on discourse were considered. Although no significant differences were found according to age at injury, a consistent pattern of generally poorer discourse scores was found for the early injured group (< 5 years). With regard to lesion focus, the group findings were unimpressive. However, preliminary examination of individual CHI cases with relatively large lateralized lesions suggested that the late injured children may show the language-brain patterns reported in brain-injured adults, whereas early injured children may not.

Frontal Lobe Changes after Severe Diffuse Closed Head Injury in Children

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 by magnetic resonance imaging (MRI). This study quantitated the morphological effects of CHI on the frontal lobes in children who sustained head trauma of varying severity. The MRI findings of 14 children who had sustained severe CHls (Glasgow Coma Scale score of ≤8) were compared with the findings in a matched group of 14 children having sustained mild head injuries (Glasgow Coma Scale score of 13-15). The patients ranged in age from 5 to 15 years at the time of their MRls, which were acquired at least 3 months postinjury. MRI findings revealed no focal areas of abnormal signal in the frontal lobes. Volumetric analysis disclosed that the total prefrontal cerebrospinal fluid increased and the gray matter volume decreased in the patients with severe CHI, relative to the mildly injured comparison group. Gray matter volume was also reduced in the orbitofrontal and dorsolateral regions of the brains of children with severe CHI, relative to the children 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 CHls were moderately disabled after an average postinjury interval of 3 years or more, whereas 12 of the 14 patients with mild CHls attained a good recovery (2 were moderately disabled) by the time of study. Although this initial study of brain morphometry after CHI in children was not designed to isolate the contribution of frontal lobe damage to residual disability, further research involving a larger sample is in progress to address this issue.

The Relative Durations of Coma and Posttraumatic Amnesia after Severe Nonmissile Head Injury: Findings from the Pilot Phase of the National Traumatic Coma Data Bank

Publisher Summary This chapter discusses the relative durations of coma and post-traumatic amnesia after severe nonmissile head injury. Neurosurgeons have widely adopted Glasgow coma scale (GCS) measure to assess the acute impairment of consciousness and duration of coma after head injury. This advance in the assessment of impaired consciousness has permitted a direct measurement of coma apart from the transitional, post-comatose stage of disturbed consciousness characterized by confusion, disorientation, and anterograde and retrograde amnesia. The analysis of individual components of the GCS score also failed to demonstrate a significant effect for hemispheric lateralization of mass lesion. It is conceivable that concomitant diffuse or multifocal trauma to the brain in severe head injury obscures the effects of hemispheric lateralization of injury on the disturbance of impaired consciousness that has been reported for acute vascular insult and intra-carotid amytal injection.