| Name | Luigi |
| Surname | Trojano |
| Institution | Università degli Studi della Campania Luigi Vanvitelli |
| luigi.trojano@unicampania.it | |
| Address | Department of Psychology, University of Campania 'Luigi Vanvitelli', Viale Ellittico 31, 81100 Caserta, Italy |
A patient is described who was affected by degenerative dementia and who developed severe constructional apraxia. She showed a dissociation between the construction of horizontal lines (impaired) and oblique or vertical lines (spared) which has never been reported previously. A battery of tests disclosed that this phenomenon was consistent across a range of experimental conditions and that a similar dissociation was evident in perceptual and representational domains. This peculiar clinical finding suggests that mental representations of horizontal and vertical spatial relations in an egocentric coordinate system are functionally dissociated.
We assessed neuropsychological performances of 22 patients affected by Autosomal Dominant Cerebellar Ataxia type 1. All subjects completed a comprehensive battery of standardized tests requiring a verbal response, without time constraints. In order to verify the hypothesis that disease severity is the major factor in determining the cognitive status in this syndrome, patients were divided into three groups according to the severity of the clinical picture, as evaluated by the Inherited Ataxias Progression Scale (IAPS). Statistical analysis of the three groups' raw scores showed a significant decrement in patients with more severe clinical pictures on verbal short-term memory tasks. A similar trend, but not significant, was seen for general intelligence tests and verbal learning tasks. The decrement of verbal short-term memory could be related to motor speech problems. On the other hand, the decline of cognitive abilities over the course of the Autosomal Dominant Cerebellar Ataxia type 1 was not homogeneous enough to ensure statistically reliable trends. Therefore, this cross-sectional study suggests that the progression of the disease is a necessary factor in determining cognitive decline, but it is not sufficient. Other disease-related factors (age at onset, genotypic variety) could play a critical role: among these, the size of the expanded CAG repeats is significantly related to a decline of verbal intelligence and short-term memory in SCA2 patients.
We report a 2-year prospective neuropsychological study of five asymptomatic subjects with magnetic resonance imaging (MRI) abnormalities from an Italian kindred affected by cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). These subjects completed tests for attention capacities, processing speed, abstract thinking, short-term memory, learning and constructional praxis. Seven normal subjects matched for age and education, belonging to the same pedigree and not having MRI hyperintensities were examined as controls. The results did not show significant differences between asymptomatic subjects and normal controls. Cognitive performance of asymptomatic subjects did not deteriorate during a 2-year follow-up. Our findings suggest that, at this stage of the disease process, the presence of diffuse leukoencephalopathy does not imply subtle cognitive defects.
We report on a patient affected by selective drawing disabilities. The patient could correctly reproduce and draw simple geometric figures on request, but when he tried to reproduce more complex drawings or to draw common objects he performed very poorly. To identify the cognitive impairment in this patient, we adopted two test batteries based on recent information-processing models of drawing. Results showed that the patient's drawing disabilities were independent of visuo-perceptual and executive impairments. These findings support recent cognitive models of drawing abilities: some intermediate stages of drawing exist at which information is processed to prepare and guide motor output, and which may be selectively disrupted after discrete cerebral lesions.
We describe a simple, three-dimensional constructional test (the Box test), which reflects common daily-living activities, to be used for the assessment of constructional disability in elderly brain-lesioned patients. Subjects are required to put as may of 12 objects of varied shape and volume as they can into a box. To carry out the task successfully subjects have to arrange the items according to an efficient constructional strategy. We administered this test to 68 normal subjects and to 50 brain-damaged patients. Analysis indicated the Box test is easy and simple to administer and can be used without difficulty by elderly patients having focal brain damage. Performance correlated well with general intelligence and other bidimensional, conventional constructional tasks. Right or left brain lesions have a similar, significant detrimental effect on performance but probably through different mechanisms.
We report the case of a patient affected by a subcortical lesion of the right non-dominant hemisphere, and demonstrate that he had selective constructional disorders by comparing his post-stroke performances with those assessed 18 months before the stroke. A detailed analysis was made of the visuospatial, perceptual, representational and executive competences involved in drawing tasks at one, two and six months post-stroke. Neuropsychological follow-up revealed the progressive recovery of all visuospatial abilities. This study provides some interpretative elements for constructional disorders and, in particular, for the closing-in phenomenon observed only during the subacute phase.
A patient with selective auditory phonological coding defect is described. He also showed a defective auditory verbal short-term memory but could learn lists of words flawlessly, thus closely resembling patients with pure short-term memory defects. We argue that the patient's functional defect could be conceived as a capacity limitation of the phonological short-term store. An experimental evaluation of his verbal short- and long-term memory performances allows a discussion of the interaction of phonological and lexical coding processes in verbal short-term memory and learning.
The present study aimed at controlling two variables that may affect the visuospatial short-term memory of Alzheimer patients: visuospatial coding efficiency and response modality. Thirty patients affected by Alzheimer-type dementia with relatively spared visuo-perceptual functions were tested under three conditions, all of which employed the same kind of stimuli (visuospatial patterns). At all memory tasks, patients achieved scores significantly lower than those of 30 age- and education-matched normal subjects. Patients did not benefit from longer presentation time, nor did their performance improve with pointing response modality, although they performed perceptual pattern recognition as well as did controls. These data confirm that visuospatial immediate memory capacity is reduced in dementia.
The purpose of the present study was to investigate the imagery ability of 8 "probable" Alzheimer disease patients using a standard task sensitive to the disruption of the imagery system. These patients were selected based on their good performance on a prerequisite clock-setting task, and with 8 matched control subjects were then required to compare the angles made by the hands on clock faces using only imagined stimuli. There were no significant differences between patients and controls in performance on the clock-imagery task. These data are consistent with models of information processing which postulate the relationships between visual imagery and a short-term memory store and include a central executive system for allocation of cognitive resources.
Corsi's block-tapping task was given to 30 normal subjects and 38 Alzheimer-type demented patients following two different procedures. The first is the most widely standardized (scoring criterion: 3 correct reproductions out of 5 sequences), while the second is more lenient since it does not require subjects to replicate a certain performance three times. Demented patients' scores were lower than those of controls in both conditions, and scores on the two tasks were significantly correlated for patients and controls. However, the requirement of replicating the visuospatial memory performances was more detrimental for demented patients than for controls so the two procedures cannot be considered equivalent.