The pattern of functional deficits implicates at least two principal neural systems: the cerebellar-frontal system and the corticocortical system between the prefrontal and parietal cortices. In addition, age and amount of alcohol consumption were better predictors of motor than cognitive impairments.

No abstract

No abstract

Patients with Parkinson's disease (PD) become dependent upon caregivers because motor and cognitive disabilities interfere with their ability to carry out activities of daily living (ADLs). However, PD patients display diverse motor and cognitive symptoms, and it is not yet known which are most responsible for ADL dysfunction. The purpose of this study was to identify the contributions that specific cognitive and motor functions make to ADLs. Executive functioning, in particular sequencing, was a significant independent predictor of instrumental ADLs whereas simple motor functioning was not. By contrast, simple motor functioning, but not executive functioning, was a significant independent predictor of physical ADLs. Dementia severity, as measured by the Dementia Rating Scale, was significantly correlated with instrumental but not physical ADLs. The identification of selective relationships between motor and cognitive functioning and ADLs may ultimately provide a model for evaluating the benefits and limitations of different treatments for PD.

Few investigators have studied whether the behavioral effects of brain insult in adulthood are stable after the period of maximum recovery. We addressed this issue in a 30-year longitudinal study of 84 veterans of World War II, 57 with penetrating head injury (HI) and 27 with peripheral nerve injury (PNI), matched with respect to age, premorbid intelligence, and premorbid education. Each subject was examined during the 1950s and during the 1980s; each examination included the largely verbal Army General Classification Test (AGCT) (with Vocabulary, Arithmetic, and Block Counting subscales) and the Hidden Figures Test (which measures figure-ground discrimination). HI exacerbated decline in performance over time, irrespective of lesion site or cognitive test. HI and PNI subjects differed significantly (p less than 0.05) in AGCT Total and Arithmetic change scores, and means were in the same direction for all other measures. In analyses contrasting subjects in each of the eight lesion groups to PNI subjects, those with left parietal lobe injuries showed significantly greater decline from the 1950s to the 1980s on the Vocabulary and Arithmetic subscales of the AGCT, as did those with left temporal lobe injuries on the Arithmetic subscale, whereas subjects with right parietal lobe injuries showed significantly greater decline on the Hidden Figures Test. We hypothesize that the observed reduction of cognitive capacities late in life was due to some combination of HI in young adulthood, secondary effects of the injury occurring with time, effects of stress on remaining brain tissue caused by functioning for decades in a compromised state, and changes in the brain occurring with age. Although the HI subjects were not demented, follow-up studies must assess whether exacerbated decline is a harbinger of dementia.

The surgical procedure and the device are reasonably safe. Adverse events were consistent with shunt procedures for hydrocephalus in this older population. The endpoint data show a trend in favor of the treated group. A larger, randomized, double-blinded, controlled, clinical trial is underway.

Patients with Parkinson's disease (PD) displayed a different pattern of cognitive deficit from patients with dementia resulting from Alzheimer's disease (AD). Specifically, PD patients, whether or not impaired on a mental status examination, had deficient Picture Arrangement but normal Vocabulary test scores whereas AD patients were impaired on both measures. Furthermore, PD patients with impaired mental status examination scores showed a deficit in set formation on Picture Arrangement not seen in the AD patients. Finally, when recent memory performance, as measured by the Wechsler Memory Scale, was predicted from an estimated IQ, 71% of PD patients who had normal mental status examination scores were seen to have at least a mild memory impairment.

In a study of verbal temporal ordering, patients with Parkinson's disease (PD) were impaired in making judgements of the relative recency of serially-presented words but were normal in word recognition; by contrast, patients with Alzheimer's disease (AD) were impaired on both verbal tasks (Sagar et al., 1985, 1988b). The present study used a nonverbal analogue of the verbal temporal ordering task to examine whether the deficit in recency discrimination of the PD patients transcended material-specific bounds or was specific to verbal material. The nonverbal task was administered to the patients with PD, patients with AD and normal control subjects studied with the verbal task. The results showed that the retention functions for the recognition of verbal and nonverbal material differed qualitatively from each other and this difference was present in all three subject groups. For verbal and nonverbal recency discrimination and verbal content recognition, performance declined with increasing retention intervals; for nonverbal content recognition, however, performance was essentially unchanging across retention intervals. As on the verbal test, recency discrimination on the nonverbal test was impaired in both patient groups. In contrast to the results with the verbal task, both groups were impaired on content recognition. The patterns of impairment, however, differed between the two patient groups in a parallel way to those of the verbal task: performance of the AD group was impaired at the longest retention intervals but not at the shortest intervals, whereas the performance of the PD group was impaired at the shortest but not at the longest intervals. This deficit in nonverbal short-term recognition memory was present even in PD patients who scored within the normal range on a quantitative test of dementia. These results show that deficits in recency discrimination and short-term memory processing in PD extend to nonverbal as well as verbal material and imply bilateral frontal lobe dysfunction in the genesis of these deficits.