Assessment of subjective sensitivity to the induction of the PH and associated bodily states, for different populations of PD patients and healthy aged-matched controls

Investigation of neural mechanisms at rest, that are potentially disrupted at different degrees, for the different clinical groups of PD patients, compared to the healthy aged-matched controls

Assessment of subjective sensitivity to the induction of the PH and associated bodily states, for different populations of PD patients and healthy aged-matched controls Assessment and comparison of the neural mechanisms responsible for the induction of the PH and associated bodily illusions, in different groups of PD patients and healthy aged-matched controls

The SAPS is a validated clinical rating scale measuring positive symptoms of schizophrenia, recommended by the MDS to assess psychotic symptoms in PD, in the absence of a reliable validated one. The scale is sub-categorised into 4 domains within which specific symptoms are evaluated from 0 (absent) to 5 (severe): Hallucinations (67 items + 1 global evaluation item) (e.g., visual, auditory) (range 0-30); Delusions (12 items + 1 global evaluation item) (e.g., persecution, thought insertion) (range 0-60); Bizarre behaviour (4 items + 1 global evaluation item) (e.g., agitation, social behaviour) (range 0-20); Positive formal thought disorder (8 items+ 1 global evaluation item) (e.g., incoherence) (range 0-40) A composite score is calculated by adding the scores of each non-global item.. A global score of severity of symptoms with regard to duration and persistence of symptoms can be calculated by adding the scores of the global evaluation items.

This questionnaire is based on previous lab research and is a semi-structured interview on hallucinations and other psychotic symptoms. The frequency of symptoms is evaluated on a scale from 0 to 4. Two scoring systems are proposed to evaluate severity of symptoms (from 1-3): Severity score 1 refers to the impact of the symptoms on the patients' environment (ex: caregivers, family) as defined by the patients; Severity score 2 refers to the clinical severity as estimated by the clinician during the clinical interview. A composite score for each symptom is calculated: Frequency x Severity 1 (and Frequency x Severity 2). The composite scores of each symptom are then added to obtain the total score for the Category. The total score of the full scale is calculated by adding the total scores of Category A to E. The greater the score, the more frequent and severe the symptoms are.

The Hospital Anxiety and Depression Scale is a 14-item self-assessment scale found to be a reliable instrument for detecting states of depression and anxiety. Seven items are dedicated to assess anxiety and the 7 others for depression on a 4-point Likert scale from 0 to 3.. A score > greater than 11/21 for each domain (anxiety or depression) indicates a considerable symptomatology for depression or anxiety.

The REM Sleep Behaviour Disorder Screening Questionnaire is a self-report 13-item questionnaire assessing clinical features of REM sleep, and is a potential marker for PD. A "yes" (score 1) or "no" (score 0) is provided for each item. A maximum score of 13 indicates severe REM sleep behaviour disorders.

a 15-item self-report questionnaire assessing the cognitive processes involved in the re-evaluation of anomalous experiences and their misinterpretations, i.e., distancing, objectivity, perspective, and self-correction. Subjects will rate on a scale from 0 (do not agree at all) to 3 (agree completely) how much they agree with each statement. A general insight ratio can also be calculated: self-reflectiveness sore/self-certainty score. High score reflects better cognitive insight (max=6).

This is a 3-item scale assessing the overall subjective feeling of loneliness in elderly populations from 1 (hardly) to 3 (often). A maximum score of 9 indicates the highest level of subjective feeling of loneliness.

The Dimensional Apathy Scale is a 24-item self-report questionnaire assessing three apathetic subtypes; namely cognitive, emotional-affective and auto-activation apathy. Subjects rate on a scale from 0 (almost always) to 3 (hardly ever) how much they agree with each statement. The scale provides the following sub-scores: (1) executive subscale, (2) emotional subscale and (3) behaviour/cognitive initiation subscale. A total score can be calculated. The maximum of each sub-scale is 24 and the total is 72. The cut-off score for each sub-scale are as follows:

Executive: 14 Emotional: 15 Initiation: 16 Scoring below the cut-off indicates substantial clear apathetic symptoms.

The Questionnaire for Impulsive-compulsive Disorders in Parkinson's Disease self-rating assesses 7 major behaviours :1. Gambling, 2. Sex, 3. Buying, 4. Binge eating, 5. Hobbyism, 6. Punding and 7. Excessive medication use. Each behaviour is assessed by means of 4 questions on a Liket type scale from 0 (never) to 4 (very often). The scores of for each behaviour range from 0-16, and the total score to the scale ranges from 0-112. High scores reveal impulsive-compulsive disorders.

The Neuropsychiatric Fluctuations Scale for Parkinson's Disease is a 20-item self-report questionnaire. Ten items represent neuropsychiatric symptoms typically reported by patients in the OFF-medication condition and ten items measure neuropsychological symptoms typically reported by patients in the ON-medication condition. Subjects rate on a scale from 0 (no) to 3 (a lot) how much they agree with each statement. The scale provides two sub-scores, one for the ON-Items and one for the OFF-Items, ranging from 0-30. High scores indicate either ON-behaviours corresponding to ON-states (eg. euphoria, excitement) or OFF-states behaviours such as anxiety, lack of energy and fatigue.

Parkinson's disease - Cognitive Rating Scale is a battery of neuropsychological tests specifically designed to capture the whole spectrum of cognitive impairment in patients with PD. This battery provides, as stated by the Movement Disorders Society:

• Frontal subcortical tasks (sustained attention, working memory, alternating and action verbal fluency, clock drawing, immediate and delayed free recall verbal memory). Scores range from 0-104.
• Posterior cortical tasks (confrontation naming and clock copying), with scores ranging from 0 to 30.
• Total scores range from 0-134 High scores are indicative of preserved cognitive functions.

Within 2 minutes, participants generate orally as many animal names as possible for the semantic fluency task, and as many words starting with letter P for the phonemic task, while respecting the following rules: no repetition and no word with the same root, and no proper nouns. The total number of words correctly named, and the number of errors are taken into account. Z-scores will be calculated.

The test consists of squares containing 5 dots (like the number five on a dice). Participants are instructed to draw as many different patterns as possible, within 3 minutes, by connecting the dots by means of straight lines. The number of unique designs (maximum=80) and errors are counted. Z-scores will be calculated.

The Trail Making Test is a test during which the execution of the task is timed. The time taken to complete the test are noted as well as the number of errors. Z-scores will be calculated.Part A explores perceptual-motor speed (visuo-motor tracking) while part B requires more psychomotor speed and working memory.

This sub-test, derived from the Wechsler Adult Intelligence Scale, assesses visuo-motor information processing speed within 2 minutes. Participants scan a search group and indicate whether one of the non-verbal symbols in the target group matches. The raw scores obtained are converted to standard scores with respect to participant's age. Cuff off of standard score = 10. Scores below 10 are considered under the normal range.