Cognitive-linguistic subgroups in closed-head injury

Abstract

This study examined variability in the interrelationship between language skill and neuropsychological function within a group of 25 severe closed head injury (CHI) subjects and 23 matched controls. All subjects underwent a battery of standardized language and neuropsychological tests. Cluster analyses were conducted to determine whether the CHI sample was universally or differentially impaired. Further subgroup analysis using a Q type factor analysis outlined the differences in performance profiles within the group of CHI subjects. Results support the hypothesis that while some deficits were common to all CHI subjects, impairments delinated by whole group analysis do not necessarily represent universal impairments. In particular, ability to perform tasks involving auditory comprehen sion, naming, verbal memory, visual memory and visuospatial skills appeared to be important com ponents in group differentiation. The cognitive linguistic impairments which were common to all CHI subjects and considered to be the lcardinal cognitive-linguistic deficits following severe CHI were deficits in lexical-semantic and sentential semantic skills, verbal fluency, complex auditory comprehension, and attentional operations. Profile analysis revealed the existence of a double dissocia tion between performances on naming and verbal memory tasks and performances on visually related cognitive tasks. Results are discussed with reference to findings on previous studies of subgroups in the CHI population.