Cognitive recovery after severe head injury. 2. Wechsler Adult Intelligence Scale during post-traumatic amnesia.

Abstract

SYNOPSIS The Wechsler Adult Intelligence Scale (WAIS) was administered to two matched groups of severely head-injured patients. The first administration was early in the recovery period, when group I was still in post-traumatic amnesia. The WAIS results for this group were significantly lower than those of group II, who were fully conscious. A follow-up at a later stage of recovery found that group I had substantially caught up with group II on the WAIS. At both administrations the WAIS subtest scores were correlated with clinical data, and changes in the pattern of correlations between PTA and full consciousness suggested that the former represents a qualitatively, and not merely quantitatively, distinct phase of recovery.Post-traumatic amnesia (PTA) is a period of clouded consciousness which precedes the attainment of full orientation and continuous awareness in persons recovering from head injuries. Its duration, which may range from minutes to months, is claimed to be an index of the severity of the head injury (Russell, 1971). PTA appears to be characterized primarily by a failure of mnestic processes, insofar as the patient on subsequent questioning is able to recall at best only isolated incidents which occurred during this period. It is not surprising therefore to find that the psychological studies on head-injured persons during PTA have been concerned above all with memory (Fodor, 1972;Dunn and Brooks, 1974

Cognitive recovery after severe head injury. 3. WAIS verbal and performance IQs as a function of post-traumatic amnesia duration and time from injury.

“…Of particular interest is the finding that, in the longer term, IQ levels were indistinguishable on the basis of PTA duration alone, though a trend was apparent for the longer PTA groups to score slightly less well than the shorter PTA groups. This too is consistent with earlier findings (Mandleberg, 1975 (SD= 15.11), and mean PTA duration for the group as a whole was approximately five weeks (range = four days to approximately six months). The majority of the patients had left school at ages 15 or 16 years.…”

“…Indirect evidence suggesting that in the relatively long term PTA duration may be of little value in predicting cognitive status is seen in the finding of Mandleberg and Brooks (1975) that a group of severely injured patients eventually reached average levels of ability on the Wechsler Adult Intelligence Scale (WAIS). At the same time, Mandleberg (1975) reported that by about 18 months after injury a group of more severely injured patients (mean PTA = 110 days) had essentially 'caught up' cognitively with an otherwise comparable, though less severely injured, group (mean PTA= 19 days). Moreover, preliminary data presented by Bond (1975), though not subjected to statistical analysis, suggested that PTA duration did not appear to affect cognitive level in the longer term.…”

“…While it is characterised primarily by a failure of mnestic processes, a recent study (Mandleberg, 1975) has demonstrated a more general cognitive disability during this period, particularly for nonverbal task-skills; in consequence, the suggestion has been made that PTA represents a qualitatively, and not merely quantitatively, distinct phase of recovery.…”

WAIS-R pattern clusters after blunt-head injury

“…Given previous evidence that PIQ shows greater decrements during the more acute phases of injury (Becker, 1975;Benayoun et al, 1969;Drudge et al, 1984;Mandleberg, 1975;Mandleberg & Brooks, 1975), it is of interest that no effects for time post-onset were found between clusters. One might have predicted that some of the clusters with significantly lower scores on Performance subtests might show less time since injury.…”

“…For example, several studies have shown PIQs to be more affected than VIQs soon after head injury (Becker, 1975;Benayoun, Guey, & Baurand, 1969;Drudge, Williams, Kessler, & Gomes, 1984;Mandleberg, 1975;Mandleberg & Brooks, 1975), but greater improvements in PIQs over the first year post injury or even after lead to the disappearance of this Verbal-Performance discrepancy (Drudge et al, 1984;Mandleberg & Brooks, 1975). Klave and Cleeland (1972) found that PIQ was more related to neurologic indices (e.g., hematoma or longer coma) than was VIQ.…”