Postural instability and gait disability: related but separable manifestations of Parkinson’s disease

Recruitment & Eligibility

Status: Recruiting

Sex: Not specified

Target Recruitment: 50

Inclusion Criteria

Parkinson's disease patients
• right-handed men/women of age > 18 years.
• written informed consent
• idiopathic PD, according to the UK Brain Bank Criteria.
• disease severity 2.5, 3 or 4 on the Hoehn & Yahr scale (gait and/or balance disorders but still able to walk/stand independently.
• gait and/or balance impairments that remain present during an optimal ON state, i.e. after a challenge with a supramaximal levodopa dosage. For this purpose, we will use criteria used previously in neurosurgery studies by our collaborators in Grenoble, and define ‘gait impairment’ as a UPDRS part III score ≥2 for the Gait item. Similarly, postural instability will be defined as a UPDRS III score ≥2 for the Pull test item, or a score ≥2 for the item ‘Falls unrelated to freezing’ of the UPDRS part II.

Controls
• right-handed men/women of age > 18 years
• written informed consent

Exclusion Criteria

Parkinson disease patients
• patients with levodopa-induced gait or balance disorders (e.g., levodopa-induced freezing of gait). We will therefore exclude patients who score greater on levodopa than off levodopa on the gait, balance or freezing items of the UPDRS. • failure to lay still for 90 minutes in the scanner (for example due to head tremor or medication-induced excessive movement)
• failure to stand/walk independently
• other causes of clinically relevant gait difficulties (eg, orthopedic or vestibular disorders)
• contra-indications for MR scanning (eg, clautrophobia)
• other neurological disorders such as stroke in history or a psychiatric disease
• depression
• cognitive impairment (MMSE <26).
• severe comorbidity (eg cancer)
• pregnancy
• poor eyesight

Controls
• failure to lay still for 90 minutes in the scanner (for example due to head tremor or medication-induced excessive movement)
• failure to stand/walk independently
• causes of clinically relevant gait/balance difficulties (eg, orthopedic or vestibular disorders)
• contra-indications for MR scanning (eg, claustrophobia).
• any neurological disorders such as stroke in history or a psychiatric disease
• depression
• cognitive impairment (MMSE <26).
• severe comorbidity (eg cancer)
• pregnancy
• poor eyesight

Study & Design

Study Type: Observational non invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
The primary objective of this study is to compare the brain activity of PD patients with prominent balance or gait impairments while they mentally imagine swaying or walking respectively.<br>

Secondary Outcome Measures

Name	Time	Method
A secondary objective of this study is to compare the brain activity of PD patients with balance impairments and a group of healthy subjects while they mentally imagine swaying.<br>We will also analyse the covariation of the BOLD signal with behavioural variables in PD patients. Namely, baseline GBI severity (measured quantitatively) will be used as covariate. <br>