| 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 |
We report a patient who, following a focal ischemic lesion of the left basal ganglia, developed right hand micrographia characterised by progressive reduction of letter size during writing (progressive micrographia). The patient did not show relevant cognitive impairments, but achieved pathological scores in tests for verbal fluency, and cognitive flexibility and monitoring. A systematic investigation of the writing performances demonstrated that micrographia showed a clear length effect in whatever writing style or task, while it was not observed in drawing, or in left hand writing to a comparable extent. Right hand progressive micrographia was not affected by a concurrent motor and cognitive load; instead, switching between two kinds of allographic responses and presenting one letter at a time in copying tasks reduced severity of micrographia significantly. These findings support the view that progressive micrographia in our patient could be ascribed to a defect in regulating the motor output on the basis of self-generated strategies. This conclusion would be consistent with neuroimaging evidence about the role of the basal ganglia in the control of motor sequencing, and could suggest that progressive micrographia might be associated with specific executive defects.
Subjective memory complaint is a self-reported memory impairment which affects elderly people. This problem does not interfere with daily living activities but could decrease quality of life. This study's purpose was to verify whether a specific, newly developed, autobiographical recall training could modify self-perception of memory of subjects with subjective memory complaint. Seven elderly subjects (4 women and 3 men; mean age 65.5 yr., SD=11) with such complaint, evidenced through a specific questionnaire, attended the training course and were prospectively assessed on standard neuropsychological tests, depressive symptomatology, and self-perception of memory. Self-perception of memory, as assessed by scores on a formalized questionnaire, improved significantly after the training, while depressive symptoms did not change. Neuropsychological performances were normal before and after the training, but a statistically significant improvement was observed only on the phonological fluency test. Thus the present pilot study suggested that the training may be effective in improving self-perception of memory and metamnestic capacity in elderly people with subjective memory complaints but not in changing subjects' depressive symptoms. This requires replication of this work with a much larger sample so statistical power is adequate.
We describe a follow-up study of a patient with a selective, progressive impairment of topographical orientation. The patient's topographical difficulties were evident only in unfamiliar surroundings at the beginning of the observation period but later on they were observed even at home. Serial neuropsychological tests demonstrated a progressive impairment of visuospatial abilities with sparing of the other cognitive domains; only at the last assessment, about six years after early disturbances and three years after the first evaluation, the patient developed the typical cognitive impairments of Alzheimer's disease (AD). This case represents a focal variant of AD not previously described and suggests that the neuronal pathways underlying spatial orientation may be selectively damaged by the degenerative process.
Using repetitive transcranical magnetic stimulation (rTMS), we investigated the functional relevance of posterior parietal cortex for categorical and coordinate judgements in the spatial imagery domain. In the coordinate task, subjects were asked to imagine two analogue clock faces based on acoustically presented pairs of times, and to judge at which of the two times the clock hands form the greater angle (mental clock task); in the categorical task subjects were again asked to imagine an analogue clock face showing the time verbally presented by the examiner, but in this case they had to judge whether both hands lay in the half of the clock face cued by an auditorily presented label. We matched the performance of three groups of subjects, two of which received rTMS stimulation over left and right posterior parietal cortex, respectively, while the third group received a sham stimulation. The results showed that right parietal stimulation interfered with the execution of the coordinate task, while left parietal stimulation mainly affected the categorical task, but also reduced the learning effect on the coordinate task. The present findings support the hemispheric specialization of the posterior parietal cortex in different spatial information processing in the imagery domain.
Hallucinations occur in patients with Parkinson's disease (PD) with reported prevalence ranging from 8% to 40%. Hallucinations are significantly associated with dementia in PD, but little is known about possible distinctive cognitive features of non-demented PD patients who develop hallucinations.
The authors report a patient with a right frontal stroke who, despite the ability to draw clocks accurately from memory, translocated numbers on the inferior half of the dial to the superior half when copying a clock. In further graphic and verbal clock reproduction tasks, transpositions were always directed toward the model but disappeared in a delayed copying task. These findings appear to reflect an intentional disorder characterized by pathologic approach behavior.
We tested 125 normal subjects and 24 right and 22 left focal brain-damaged patients (RBD and LBD) on the Rey figure copying test and on a battery of perceptual and representational visuospatial tasks, in search of relationships between constructional and visuospatial abilities. Selected RBD and LBD were not affected by severe aphasia, unilateral spatial neglect or general intellectual defects. Both RBD and LBD showed defective performances on the constructional task with respect to normal subjects. As regards visuospatial tasks, both patient groups scored lower than normal subjects in judging angle width and mentally assembling geometrical figures; moreover, RBD, but not LBD, achieved scores significantly lower than healthy controls in judging line orientation and analyzing geometrical figures. Post-hoc comparisons did not reveal any significant differences between RBD and LBD. Multiple regression analysis showed that visuospatial abilities correlate with accuracy in copying geometrical drawings in normal subjects and in RBD, but not in LBD. From a theoretical perspective, these findings support the idea that visual perceptual and representational abilities do play a role in constructional skills.
We describe a neglect patient who showed systematic transpositions of left-sided items onto the right side in clock drawing. When the patient had to write single hours on blank clock dials he again showed allochiria, while he copied single spatial locations without transpositions. The patient also showed a variable number of spatial transpositions on imaginal tasks with well known and novel material acquired through visual modality and on controlled constructional tasks, independently from response modality (verbal, graphic or motor). From this basis, we argued that spatial transpositions may derive from an impairment of the mental representation of space. Moreover, we speculated that such errors may result from cognitive conflict between different sources of information.