H Spinnler

Dementia, ageing, and the structure of human memory

Abstract The memory performance of patients suffering from senile dementia of the Alzheimer type (SDAT) (N = 29), normal subjects of equivalent age and education (N = 58), and young normal controls (N = 42) was tested using free recall and verbal and nonverbal span. Three measures were derived from the free recall task: primacy based on the first item, secondary memory based on the middle serial positions, and primary memory based on recency and the Waugh-Norman correction factor. The SDAT patients differed from the normal elderly on all free recall and span measures except for primary memory. The elderly were clearly inferior to the young on secondary memory, and were marginally poorer on primary memory and the two span measures. Three possible explanations of this pattern of results are considered, based on the dichotomous modal model of memory, levels of processing, and working memory. It is suggested that the assumption that SDAT patients suffer from a deficit in the central executive component of wor...

Gait apraxia after bilateral supplementary motor area lesion

Objectives: The study aimed at addressing the issue of the precise nature of gait apraxia and the cerebral dysfunction responsible for it. Methods: The case of a patient, affected by a bilateral infarction limited to a portion of the anterior cerebral artery territory is reported. The patients ability to walk was formally assessed by means of a new standardised test. Results: Due to an anomaly within the anterior cerebral artery system, the patients lesion was centred on the supplementary motor regions of both hemispheres. He presented with clear signs of gait apraxia that could not be accounted for by paresis or other neurological deficits. No signs of any other form of apraxia were detected. Conclusions: The clinical profile of the patient and the analysis of 49 cases from previous literature suggest that gait apraxia should be considered a clinical entity in its own right and lesions to the supplementary motor areas are responsible for it.

Walking difficulties in patients with Alzheimer’s disease might originate from gait apraxia

Objectives: To investigate whether gait apraxia is a possible cause for some of the walking abnormalities shown by patients with Alzheimer’s disease. Methods: 60 patients with Alzheimer’s disease, selected as being free from overt extrapyramidal impairment or other potential causes of walking deficits, were assessed with a new test evaluating aspects of walking and related movements. Norms for this test were collected from a sample of 182 healthy volunteers. Results: 40% of the Alzheimer group performed below the cut off score on this test, and half performed poorly. Performance of the Alzheimer group in the walking skills test correlated highly with scores in a test assessing limb apraxia and with dementia severity. Conclusions: Gait apraxia may be the cause of walking disorders found in a subgroup of patients with Alzheimer’s disease. Its detection is made easier by the use of a standardised test, but still relies heavily on the exclusion of other causes of walking deficits. It is a recognisable and independent form of apraxia.

Slowly progressive impairment of spatial exploration and visual perception

Abstract We describe three cases of progressive visuo-spatial impairment. When tested, all patients exhibited Balint-Holmes syndrome. Functions of other cognitive domains, including memory, were initially preserved. CT, MRI and PET scans revealed mild cortical atrophy, in one case more pronounced in the posterior part of both parietal lobes. The patients were followed up for several years and the progressive cognitive impairment extended to other cognitive functions (language, memory and executive functions), becoming indistinguishable from the typical profile of Alzheimers disease (AD). However, the selective impairment of visuo-spatial functions at onset, and the extensive period for which these disorders remained isolated, leave their diagnostic characterization open to debate.