Study of Memantine for Gait Disorders And Attention Deficit In Parkinson's Disease

Overall study duration: 2 years. Planned inclusion period: 12 months. Study duration for individual patients: 4 months and 2 weeks(2 weeks between screening and randomization, 3 months of double-blind treatment and then a 4-week wash-out period).

Primary objective (V1 and V4):

To assess efficacy of memantine treatment on severe gait disorders assessed on stride length by gait analysis with an optoelectronic system (VICON®) in patients with advanced Parkinson's disease under subthalamic stimulation

Additional Efficacy Endpoints (V1 and V4):

• Kinematic and Kinetic parameters (stride length, stride time, velocity, and cadence) of the gait initiation and the stabilized gait using the optoelectronic system (VICON®)
• Gait and motor symptoms: the "Freezing Of Gait trajectory", the UPDRS scores (part III), the dyskinesia rating scale,
• Axial rigidity : measured by passive flexion on isokinetic dynamometer (Cybex 6000)
• Axial strength : measured by active flexion on isokinetic dynamometer (Cybex 6000)
• Attention: simple and complex reactions times
• The inhibition of the presynaptic dopamine transporter by memantine was assessed by the mean DAT density of the bilateral striatum (putamen and caudate nuclei) using [99mTc]TRODAT-1 SPECT

Safety and Tolerability Endpoints (V1, V2, V3 and V4):

• Drowsiness: Epworth and Parkinson's disease Sleep Scales
• Apathy Lille Apathy Rating Scale
• Depression : MADRS,
• Pharmacokinetic properties of memantine were analyzed by the lowest plasmatic concentrations of memantine before the morning intake of the blinded treatment at 7:00 h, during the steady state after 3 months (blind secondary analyse).
• Safety : Recording of all serious and non serious adverse events reported by the patients, electrocardiogram, blood pressure and biological analyzes (blood counts, ionogram, urea, creatinemia, transaminases, alkaline phosphatase, bilirubinemia, gamma GT, magnesium)
• Tolerability Number of subjects (%) who discontinue the study Number of subjects (%) who discontinue the study due to AEs Safety Measures AE incidence Safety laboratory values Vital signs Blood pressure monitoring ECG Physical and neurological examination

Study Design

Monocentric study: 12-week double blind, placebo-controlled phase. After being found eligible to participate in the study, subjects will be allocated in a 1:1 ratio into one of the following two treatment groups based on a randomization scheme with blocks stratified:

one memantine

1. st week: 5 mg per day in the morning
2. nd week: 10 mg per day in the morning
3. rd week: 15 mg per day in the morning
4. th week: 20 mg per day in the morning one placebo during 3 months same as memantine

Schedule: 5 visits : screening (V0), randomization (V1, 15 days after V0), (V2) visit after 1 months, (V3) visit after 2 months and termination (V4, 3 months after randomization)

Patients : 28 subjects with Parkinson's disease duration of more than 5 years, without dementia (Mattis Dementia Rating Scale ≥ 130, MMSE ≥ 27 and DSM IV), without major depression (MADRS < 18) who have severe gait disorders including freezing of gait (defined by an answer 2 or 3 at the 3rd question of the autoquestionnaire of Giladi: Do your gait disorders impede your daily living activities and your independence: answer: yes, moderately or severely. But the patient requires no physical assistance to walk) despite an optimal dopaminergic treatment and optimal and stable subthalamic stimulation parameters. No additional therapy will be permitted during the study.

Centre : LILLE :

Department of Neurology, University Hospital of Lille : Pr L. Defebvre, Pr K. Dujardin, Dr D. Devos, Pr Destee, Mme Delliaux. Dr A Kreisler, Dr C Simonin, Dr C. Moreau, Dr A. Delval Department of Pharmacology, Faculté de Médecine, Lille II.