This study examined whether neuropsychological changes emerge over time in asymptomatic adults who have the

Recent studies have detected basal ganglia atrophy in clinically asymptomatic persons with the genetic mutation that causes Huntington's disease (HD). Whether reductions in caudate and putamen volume on MRI scans are associated with changes in cognitive and neurologic functioning was examined in 13 healthy adults with the IT-15 mutation. Reduced striatal volume was found to correlate with greater neurologic (largely motor) impairment, slower mental processing speed, and poorer verbal learning, although none of the participants met even liberal criteria for clinical diagnosis of HD. These correlations are strikingly similar to those observed in symptomatic HD patients, possibly reflecting the earliest manifestations of disease.

There have been few studies of psychogenic amnesia based on a cognitive or neuropsychological framework. In the present study, a patient with acute onset of profound psychogenic retrograde amnesia was examined. Although her performance on neuropsychological tasks revealed intact anterograde memory, language functioning, visuospatial and constructional skills, and mental speed and flexibility, she displayed severe impairments on a variety of retrograde memory tasks. Furthermore, initial observations revealed inconsistencies between the patient’s recall of semantic knowledge on direct questioning and her ability to demonstrate the use of this knowledge on indirect tasks. To test this formally, we devised an indirect remote knowledge task to examine a possible dissociation between explicit and implicit memory. Two healthy subjects matched for age, gender, education, occupation, and estimated IQ were also tested. As predicted, the findings demonstrate implicit knowledge despite impaired explicit recall for the same material. (JINS, 1996, 2, 146–158.)

Verbal (word) and nonverbal (design) paired-associate tasks were administered to Huntington's disease (HD) patients and healthy control subjects. An AB-AC paradigm, in which the cue stimuli were paired with different responses on the learning (e.g., BED-REST) and test trials (e.g., BED-SHEET), was used. It was hypothesized that HD patients would continue to respond with AB associations on the AC trials. The results were contrary to expectations: Patients showed impaired learning of both verbal and nonverbal associations but did not display a perseverative response style, even when the associative strength between word pairs was manipulated to elicit perseverations. Patients made more nonperseverative than perseverative errors in all conditions, an error pattern similar to that of control subjects. HD patients did not demonstrate increased susceptibility to proactive interference on these associative learning tasks.

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t has been known for many years that brain damage can produce I profound changes in behavior, cognition, and physical functioning that can persist well beyond the acute phase of recovery. Patients are often unaware of these changes and minimize the impact of their limitations on everyday activity. Although some patients steadfastly deny any suggestion that they are impaired, others simply do not appreciate their deficits and exhibit unconcern, disbelief, or triviality when confronted by them. It then comes as no surprise that altered self-awareness creates a major obstacle in rehabilitation and psychosocial adjustment (Ben-Yishay et al., 1985;Bond, 1984;Bond & Brooks, 1976;Ford, 1976;. Moreover, unawareness may create serious problems for family members who have trouble managing patients (Lezak, 1978(Lezak, , 1988. Given these problems, routine assessment of awareness disturbances appears critical for effective treatment and aftercare planning.Unawareness of deficit generally refers to patients' lack of insight or appreciation of a particular deficit or cluster of impairments. The term unawareness is often used interchangeably with anosognosiu and denial of illness, despite differences in the original meanings of these designations (for review, see McGlynn & Schacter, 1989; Prigatano & Schacter, 1991). Impaired awareness can manifest in different forms, be produced in various kinds of brain damage, and differ with respect to the type of assessment procedure used

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