Fifteen-year stability of some neuropsychological tests in learning disabled subjects with and without neurological impairment

The stability of the WISC/WAIS-R and seven other commonly used neuropsychological tests over a period of 15 years was investigated in 133 learning-disabled subjects, and for subgroups with hard neurological signs, soft neurological signs, and without neurological findings. Results showed high and significant correlation coefficients between time 1 (mean age 10 years) and time 2 (mean age 25 years), even though for some tests a change from the children's to the adult version occurred. Using a repeated-measures multivariate design, the three subgroups did not differ on this limited test battery. The correlation coefficients for the three subgroups provide an estimate of the range of stability in three different samples.     

Semantic dementia associated with amyotrophic lateral sclerosis

The association semantic dementia-amyotrophic lateral sclerosis has been rarely reported in the literature. We report a case study of a patient with a severe prosopagnosia in relation with semantic dementia associated, 12 months later, with a motor neuron disease.     

Procedural learning and striatofrontal dysfunction in Parkinson's disease.

The neural basis of procedural learning remains controversial. We further analyzed procedural learning in nondemented patients with Parkinson's disease (PD) according to the specific demands of the tasks and the severity of striatal and frontal lobe dysfunction. In the first experiment, the performance of 20 nondemented PD patients and matched normal control subjects was studied in two procedural learning tasks, rotor pursuit and mirror reading, that differ in terms of motor and cognitive involvement. A second experiment further assessed the relationship between learning in mirror reading and executive functions in a new group of 15 nondemented PD patients. In rotor pursuit, PD patients significantly progressed across the first sessions, although their asymptotic performance was inferior to that of controls. In mirror reading, both experiments showed substantial learning in PD patients considered as a group. However, subsequent analyses allowed us to distinguish PD patients without executive dysfunction, whose learning was normal, from PD patients with executive dysfunction, whose learning was severely impaired. These results confirm the involvement of striatofrontal circuits in procedural learning and indicate that the intervention of the frontal network may depend on the characteristics of the task.     

Apathy in patients with mild cognitive impairment and the risk of developing dementia of Alzheimer's disease: a one-year follow-up study

OBJECTIVE: To evaluate the relation between apathy and development of dementia in patients with amnestic mild cognitive impairment (MCI). METHODS: Two hundred and fifty-one French-speaking outpatients fulfilling the criteria of amnestic MCI were enrolled. Apathy was assessed with the Apathy Inventory (IA). Neuropsychiatric evaluation also included the Goldberg anxiety scale and the Montgomery and Asberg Depressive Rating Scale (MADRS). The main end point considered after a 1-year follow-up was the development of dementia of Alzheimer type (DAT). RESULTS: At baseline there were 86 (39.8%) subjects presenting at least one symptom of apathy among the 216 included in analysis. After a 1-year follow-up, 22 patients developed DAT. Of the patients with apathy at baseline 13 (15.1%) developed DAT in comparison with 9 (6.9%) of the non-apathetic patients. At the 1-year follow-up, patients developing DAT had a significantly higher frequency of apathetic symptoms (91.7%) than patients without DAT (26.9%). CONCLUSION: Taking into account that apathy is one of the most frequently observed neuropsychiatric symptoms in MCI and in DAT the present study suggests that patients with MCI and apathy should be more closely observed.     

Distinct Patterns of Antiamyloid-β Antibodies in Typical and Atypical Alzheimer Disease

OBJECTIVE To compare serum antiamyloid-β (Aβ) antibodies in typical and atypical Alzheimer disease (AD). DESIGN Preliminary observations. SUBJECTS Thirteen patients with AD, 8 patients with posterior cortical atrophy with evidence of AD (PCA-AD) pathophysiological process by both cerebrospinal fluid (CSF) biomarkers and amyloid imaging, and 12 age-matched control individuals. INTERVENTIONS The class and subclass levels of serum anti-Aβ antibodies were measured using an oligomer-based enzyme-linked immunosorbent assay. This method allowed measuring both free antibodies and, after acidic treatment, the total fraction that includes all antibodies complexed with circulating Aβ40/42 and any cross-reacting antigen. RESULTS Anti-Aβ IgG were restricted to the IgG1 and IgG3 subclasses. Their total levels were strikingly lower and more homogeneous in patients with PCA compared with both typical AD and controls, while biomarkers of amyloid deposition (CSF Aβ42 and positron emission tomography amyloid imaging) were similar in patients with AD and patients with PCA. CONCLUSIONS Serum anti-Aβ IgG1 and IgG3 antibodies differ between distinct forms of AD. Its significance is discussed for possible implications as immune effectors in the specific pathophysiology of AD variants.     

Visuospatial deficits in posterior cortical atrophy: structural and functional correlates

Objective To determine the neural substrates of biased spatial orienting in posterior cortical atrophy (PCA) by using a combined structural and functional neuroimaging approach. Background Patients with spatial neglect typically bisect horizontal long lines towards their brain lesions but the precise neural substrates of this spatial bias remain controversial and poorly explored in neurodegenerative disorders such as PCA. Methods 15 patients with PCA underwent brain MRI and single photon emission computed tomography (SPECT) and were required to bisect five 20 cm long lines, each centred on an A4 horizontal sheet. Direct correlations between average deviations on the bisection task and both (1) the degree of grey matter density, as estimated by voxel based morphometry and (2) regional cerebral blood flow, as assessed by SPECT, were performed. Results Seven patients (47%) had pathological bias on the bisection task, deviating consistently towards the non-neglected side for each of the five lines. Rightward bias (sign of left-sided neglect) was more frequent and severe than leftward bias (sign of right-sided neglect). Correlation analyses showed that rightward deviations correlated with atrophy and hypoperfusion exclusively in the right hemisphere, involving a large scale fronto-parietal network; cortical atrophy was prominent in the parieto-temporal cortex but extended to the frontal region; hypoperfusion was substantial both in the middle frontal gyrus and in the postcentral region. No correlations emerged from leftward deviations. Conclusion The results indicate that rightward bias (sign of left-sided neglect) in PCA depends on dysfunction of a large fronto-parietal network in the right hemisphere, related to both cortical atrophy and decreased cerebral perfusion.