Oculomotor Testing in the Differential Diagnosis of Dementia (OculoMacl)

• Variability of reflexive saccades latencies [ Time Frame: at one year ]
  The variability is indicated by the coefficient of variation (i.e. standard-error/mean) of saccades latencies in the gap paradigm. The variability and mean latency are expected to be increased while the percentage of express latencies decreased in DLB patients
  
  

• Correlations between oculomotor records and neuropsychological examination assessing attention abilities and their fluctuations [ Time Frame: at one year ]
  This indicator concerns the standard Bravais-Pearson correlations between saccades latencies values and scores in neuropsychological tests.
  
  
• Potential correlations between hippocampal volume and neuropsychological examination in DLB cases [ Time Frame: at one year ]
  This indicator concerns the standard Bravais-Pearson correlations between neuro-psychological test scores and the measures of hippocampal volume
  
  
• Cerebral atrophy differences between DLB and AD using SVM (Support Vector Machine) method [ Time Frame: at one year ]
  score differences between the two groups
  
  
• Percentage of alpha synuclein in CSF to discriminate DLB from AD [ Time Frame: at one year ]
  score differences between the two groups
  
  
• Variations at one year in oculomotor test scores and neuropsychological test scores [ Time Frame: at one year ]
  comparing baseline and follow-up performance separately for each group
  
  
• Mean reflexive saccades latency [ Time Frame: at one year ]
  test differences in mean reflexive saccades latency between the two groups
  
  
• Percentage of express saccades [ Time Frame: at one year ]
  test differences in proportion of express saccades between the two groups
  
  
• Correlations between neuropsychological tests scores assessing attention abilities and variability of reflexive saccades latencies [ Time Frame: at one year ]
  This indicator concerns the standard Bravais-Pearson correlations between attention abilities test scores and the coefficient of variation of reflexive saccades latencies
  
  

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia. In its early stages, the differential diagnosis of DLB and Alzheimer's disease (AD) can be challenging. The differential diagnosis is particularly important given that patients with DLB respond well to cholinesterase inhibitors but show sensitivity to neuroleptic medications which are contraindicated in DLB. DLB tends to progress more quickly than Alzheimer's disease. Diagnostic accuracy may be improved. Oculomotor recording, easy to perform could be helpful in order to identify and reliably assess fluctuating attention performance in DLB patients.

Main objective:

- to improve differential diagnosis between DLB and AD in the early stages of the disease with oculomotor measurements

Secondary objectives:

• to examine the association between the oculomotor records and neuropsychological examination assessing attention abilities and their fluctuations
• to evaluate the benefit of complementary neuropsychological tests in the distinction between DLB and AD cases
• to examine the relationship between hippocampal volume and neuropsychological examination in DLB cases
• to examine the diagnostic performance of MRI (Support Vector Machine) between DLB and AD
• to examine the interest of CSF alpha synuclein concentration to discriminate DLB from AD
• to assess at one year variations in oculomotor test scores and neuropsychological test scores Method and design Longitudinal multicenter study including 100 patients with a DLB or AD diagnosis. Clinical examination at one year.