Diagnosis of vascular parkinsonism: A new tool for gait hypokinesia occurring in older persons.

INTRODUCTION: Reliable diagnosis of vascular parkinsonism (VaP) in the presence of a gait hypokinesia is an issue that is encountered in geriatrics. The EVAMAR-AGEX study was focusing on the phenomenon of recurrent falls in older persons (OP) with this parkinsonian gait. The present study is focusing on the diagnosis of VaP-related parkinsonian gait by developing a diagnostic guidance model adapted to OP. METHODS: Data from baseline and the 2-year follow-up visit were used to carry out univariate analysis and calculation of odds ratios, allowing to identify relevant variables to include in the diagnostic guidance model. To evaluate the model, confusion matrices were created, evaluating true positive, false negative, false positive and true negative incidences, sensitivity and specificity, and negative and positive predictive values. RESULTS: 79 patients included 58% male; average age 81.24 years. VaP diagnosis according to Zijlmans criteria occurred in 28%; neurodegenerative parkinsonian syndromes in 72%. A 4-criteria model was established to facilitate diagnostic: lack of prior hallucinations, lack of movement disorders tremor excluded, no cognitive fluctuations, and ≥75 years of age at diagnosis. In combination of 4/4 criteria, all of them were required to disclose a specificity of 91% in the diagnosis of VaP. In combination of 3/4, in case of negative test, a negative predictive value for VaP diagnosis of 0.97 was obtained. CONCLUSION: The challenge of our tool is both to be able to rule out what is probably not a VaP and to argue what makes a VaP diagnosis probable in OP.

Cognitive reserve as one of the determinants of the progression of Alzheimer disease.

To assess the validity of Yaakov Stern's theory, which postulates that the first cognitive deficits of Alzheimer disease are delayed in patients with high cognitive reserve, compared to those with low cognitive reserve, but this is subsequently associated with faster cognitive decline when cerebral lesions have reached a certain degree of severity. A retrospective study of 318 patients with Alzheimer disease without associated cerebral disorders, was performed at the Memory Clinic of the University Hospital of Strasbourg. The patients were divided into five groups according to their degree of cognitive reserve, as assessed by their level of education (primary, middle school, intermediate, high school and higher education). Cognitive status was assessed by scores on the Mini Mental Status Examination (MMSE) at the first examination and during follow-up lasting four years or longer. Slopes of cognitive decline were computed and compared between groups using ß linear regression. Patients in the higher education group had higher MMSE scores than those in the other groups at the first consultation, but a statistically significant steeper slope during the follow-up. Our results are consistent with Stern's theoretical model, which assumes that high cognitive reserve is accompanied by compensation mechanisms which hinder the onset of clinical cognitive decline in patients with Alzheimer disease, but that is then associated with a faster decline at a later stage when the reserve is exhausted.

[Cognitive reserve, one of the determinants of the progression of Alzheimer's disease]. / La réserve cognitive, un des déterminants de l'évolution de la maladie d'Alzheimer.

To appraise the validity of the Yaakov Stern's theory, which postulates that the first cognitive deficits of Alzheimer's disease are delayed in patients with high cognitive reserve, compared to those with low cognitive reserve, but is subsequently associated with faster cognitive decline when cerebral lesions have reached some degree of severity. A retrospective study of 318 patients with Alzheimer's disease without associated cerebral disorders, was performed in the Memory Clinic of the University Hospital of Strasbourg. The patients were divided into 5 groups according to the degree of cognitive reserve assessed by the level of education (primary, middle school, intermediary, high school and higher education). Cognitive status was assessed by the scores on the Mini Mental Status at the first examination and during a 4-year or more follow-up. Slopes of cognitive decline were computed and compared between groups by ß linear regression. Patients in the higher education group had higher MMSE scores than those in the other groups at the first consultation, but a statistically significant steeper slope during the follow-up. Our results are congruent with the Stern's theoretical model, assuming that high cognitive reserve brings into play compensation mechanisms which hinder the onset of clinical cognitive decline in patients with Alzheimer's disease, but then is associated with a faster decline at a later stage when the reserve is exhausted.