Oculomotor Testing in the Differential Diagnosis of Dementia

Study Overview
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Brief Summary
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The aim of this study is to determine whether saccadic eye movement recording may help in the discrimination between Lewy body dementia and Alzheimer disease, in the early stages of the disease. Study type: Interventional Study design: Intervention Model: Single group assignment Primary purpose: Diagnostic

Detailed Description
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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.

Official Title
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Oculomotor Recording in the Contribution to the Early Differential Diagnosis of Dementia With Lewy Bodies and Alzheimer's Disease

Conditions
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Lewy Body Disease, Alzheimer's Disease

Intervention / Treatment
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* Other: oculomotor measurements


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged 65 and over Patients with a diagnosis of probable DLB or AD according to the Consortium on DLB criteria (McKeith et al 2005) for Lewy bodies dementia and according to DSM IV and NINCDS- ADRDA criteria for AD or patients in whom there is diagnostic uncertainty between DLB and AD No major sensory deficits MMSE > 20 Having signed an informed consent form Exclusion Criteria: Parkinson syndrome progressing for more than one year regarding cognitive impairment Use of AchEIs medication Taking or having taken anti Parkinson drugs Neuroleptic drugs over the previous three months Contraindication for lumbar puncture (i.e. anticoagulant agents) Patients with Geriatric Depression Scale (GDS) > 10 Taking medication that could impact dopamine transporter's measurement Contraindication for MRI examination Diseases involving the short-term survival (shorter than one year) Not fluent in French Major sensory deficits that could interfere with cognitive assessment (visual and auditory) Being under guardianship Absence of caregiver/informant to sign informed consent form Non health insurance affiliation

Ages Eligible for Study
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Minimum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Early stage of dementia<br>oculomotor measurements | Other: oculomotor measurements<br>* The variability is indicated by the coefficient of variation (i.e. standard-error/mean) of saccades latencies in the gap paradigm. Mean reflexive saccades latency Percentage of express saccades<br>* Other names: reflexive saccades latencies;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Variability of reflexive saccades latencies | 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 | at one year | 

Secondary Outcome Measures

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

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Alzheimer disease, Lewy Body Disease, Cognitive Disorders, Neurodegenerative Diseases, Differential diagnosis, Eye movement