Frédérique Escudier

Screening for prodromal Parkinson's disease in the general community: a sleep-based approach

OBJECTIVE/BACKGROUND Neuroprotective therapy for Parkinsons disease (PD) is most likely to be effective if provided in its prodromal stages. However, identifying prodromal PD is difficult because PD is relatively uncommon, and most markers are nonspecific. Rapid eye movement (REM) sleep behavior disorder (RBD) is by far the strongest clinical marker of prodromal PD, but most patients do not seek out medical attention. Developing an efficient way of diagnosing RBD from the general community may be the most practical method to detect prodromal PD. METHODS We developed a screening strategy that began with a newspaper advertisement containing a single-question screen for RBD. All screen-positive subjects underwent an interview based on the Innsbruck RBD inventory aimed to optimize the positive predictive value. Those who passed both screens underwent confirmatory polysomnography. The proportion of screened RBD patients who met the International Parkinson and Movement Disorder Society (MDS) criteria for prodromal PD was assessed. A broad array of clinical markers of neurodegeneration was compared between newspaper-screened RBD patients and 130 RBD patients clinically referred to the sleep center. RESULTS Of 111 RBD-screen-positive participants, 40 (36%) passed the secondary screen, and 29 underwent full polysomnography. Of these 29 patients, 19 were ultimately proven to have RBD (PPV = 66%), 12 (63%) of whom met the criteria for prodromal PD. Compared to patients referred to the sleep center, newspaper-screened patients had similar age, sex, olfaction, autonomic function, and color vision. However, motor and cognitive assessments were slightly better in newspaper-screened patients. CONCLUSIONS A multistep screening approach using RBD screening questionnaires and telephone follow-up can efficiently identify prodromal PD in the general community.

Neuropsychological performance before and after partial or complete insulectomy in patients with epilepsy

Resection of the insular cortex is becoming more frequent as it is increasingly recognized that a nonnegligible proportion of surgical candidates with drug-resistant epilepsy have an epileptogenic zone that involves the insula. In the last decades, however, the insula has been proposed to be involved in several neuropsychological functions, and there is a lack of documentation on whether partial or complete insulectomy results in permanent cognitive impairments in this clinical population. In this study, we conducted standard preoperative and postoperative neuropsychological assessments in 18 patients undergoing epilepsy surgery that included the removal of the insula in the right (n=13) or the left (n=5) hemisphere. Postoperative testing was conducted at least five months after surgery. Cognitive impairments were common and heterogeneous prior to surgery, with language and verbal memory impairments being especially frequent among patients in whom epileptic seizures originated from the left hemisphere. After surgery, declines and improvements occurred on a variety of outcomes, although new deficits were relatively infrequent among patients who had obtained normal performance at baseline. Statistical comparisons between preoperative and postoperative assessments revealed significant deterioration of only one outcome - the color naming condition of the Stroop test - which relies on oro-motor speed and lexical access. These findings suggest that partial or complete resection of the insular cortex in patients with drug-refractory epilepsy can be conducted without major permanent neuropsychological impairments in a vast majority of patients. However, small decrements in specific cognitive functions can be expected, which should also be taken into account when considering the surgical option in this clinical population.

Normative data for phonemic and semantic verbal fluency test in the adult French–Quebec population and validation study in Alzheimer’s disease and depression

Abstract Objective: Verbal fluency tasks are principally used to assess lexical access and have shown usefulness for differential diagnosis. The purpose of Study 1 was to provide normative data in the adult French–Quebec population (Canada) for semantic verbal fluency (animals), for two sets of phonemic verbal fluency (TNP and PFL), and for letter P alone (60 seconds per category/letter). The objectives of Study 2 were to establish the diagnostic and predictive validity of the present tasks and normative data in Alzheimer’s disease (AD) and major depressive episode (MDE). Method: The normative sample consisted of 932 participants aged 19–91 years. Based on multiple linear regressions, equations to calculate Z-scores were provided. To assess validity, performance of 62 healthy participants was compared to 62 participants with AD and 41 with MDE aged over 50. Results: Age and education, but not gender, predicted performance on each verbal fluency task. Healthy adults aged 50 and younger had a better performance on semantic than phonemic verbal fluency. In comparison to MDE, AD participants had lower performance on animals and TNP, but not on letter P. Ninety percent of people with a Z-score ≤ −1.50 on semantic verbal fluency had AD and the global accuracy was 76.6%. Test–retest reliability over one year was high for both animals (r = .711) and TNP (r = .790) in healthy older participants, but dropped for animals in people with AD (r = .493). Conclusions: These data will strengthen accurate detection of verbal fluency deficits in French–Quebec adults.

Cortical and subcortical gray matter bases of cognitive deficits in REM sleep behavior disorder

Objective To investigate cortical and subcortical gray matter abnormalities underlying cognitive impairment in patients with REM sleep behavior disorder (RBD) with or without mild cognitive impairment (MCI). Methods Fifty-two patients with RBD, including 17 patients with MCI, were recruited and compared to 41 controls. All participants underwent extensive clinical assessments, neuropsychological examination, and 3-tesla MRI acquisition of T1 anatomical images. Vertex-based cortical analyses of volume, thickness, and surface area were performed to investigate cortical abnormalities between groups, whereas vertex-based shape analysis was performed to investigate subcortical structure surfaces. Correlations were performed to investigate associations between cortical and subcortical metrics, cognitive domains, and other markers of neurodegeneration (color discrimination, olfaction, and autonomic measures). Results Patients with MCI had cortical thinning in the frontal, cingulate, temporal, and occipital cortices, and abnormal surface contraction in the lenticular nucleus and thalamus. Patients without MCI had cortical thinning restricted to the frontal cortex. Lower patient performance in cognitive domains was associated with cortical and subcortical abnormalities. Moreover, impaired performance on olfaction, color discrimination, and autonomic measures was associated with thinning in the occipital lobe. Conclusions Cortical and subcortical gray matter abnormalities are associated with cognitive status in patients with RBD, with more extensive patterns in patients with MCI. Our results highlight the importance of distinguishing between subgroups of patients with RBD according to cognitive status in order to better understand the neurodegenerative process in this population.

How does dementia with Lewy bodies start? prodromal cognitive changes in REM sleep behavior disorder: Cognitive Decline in Prodromal DLB

We describe the progression of cognitive decline and identify the predictive values of cognitive tests in three groups of REM sleep behavior disorder (RBD) patients classified at their last follow‐up as having Parkinsons disease (PD), dementia with Lewy bodies (DLB), or still‐idiopathic.

Normative data for the Clock Drawing Test for French-Quebec mid- and older aged healthy adults

Abstract Objective: The Clock Drawing Test (CDT) is frequently used to screen for cognitive impairment, however, normative data for Rouleau et al.’s scoring system are scarce. The present study aims to provide norms for Rouleau et al.’s scoring system that are tailored to Quebec French-speaking mid- and older aged healthy adults. Methods: Six researchers from various research centers across the Province of Quebec (Canada) sent anonymous data for 593 (391 women) healthy community-dwelling volunteers (age range: 43–93 years; education range: 5–23 years) who completed the CDT ‘drawing on command’ version. This command version (setting the clock hands to 11:10, without a pre-drawn circle) was administrated as part of a more extensive neuropsychological assessment, or along with cognitive screening instruments. Each drawn clock was scored according to the quantitative criteria set by Rouleau et al.’s scoring system. Results: CDT scores were significantly correlated with age (r(592) = −.132, p = .001) and years of education (r(592) = .116, p = .005), but not with sex (r(592) = .065, p = .112). Since data were skewed towards higher test scores, the percentiles method was used for analysis. Percentile ranks stratified by age and education are presented. Conclusion: These normative data for Rouleau et al.’s scoring system will contribute towards adequately screening for cognitive decline in Quebec French-speaking healthy adults, by also taking into account individual characteristics such as age and education.