Motor Response to Sildenafil in PD

Study Overview
=================
Brief Summary
-----------------
Sildenafil (Viagra(R))is widely used by men with Parkinsons Disease (PD) and erectile dysfunction. A number of patients have reported that when they take Sildenafil, their need of anti-PD medication is reduced. We hypotheses that sildenafil increases brain blood flow and hence improves the function of specific brain regions, improving motor function. Motor function and cerebral blood flow of 8 patients will be tested before and after Sildenafil intake and before and after anti-PD medication.

Detailed Description
-----------------
Erectile dysfunction can be experienced by up tp 40% of men with Parkinsons Disease (PD). Sildenafil (Viagra(R))is widely used by men with PD and erectile dysfunction. A number of patients have reported that when they take Sildenafil, their need of anti-PD medication is reduced. We hypotheses that sildenafil increases cerebral blood flow in basal ganglia and hence improves the function, improving motor function. Motor function and cerebral blood flow (rCBF) of 8 patients will be tested before and after Sildenafil intake and before and after anti-PD medication. rCBF will be measured by the Xe133 inhalation method and a fast-rotating, brain-dedicated, single photon emission computerized tomograph (SPECT, Tomomatic, 232, Medimatic, Inc., Denmark). Two scans will be perfomed, when patients are i)in normal medicated state and ii) in normal medicated state 1 hour after intake of 100 mg sildenafil. Motor function will be measured i 4 conditions: i)in normal medicated state and ii) in normal medicated state 1 hour after intake of 100 mg sildenafil, iii) after 12 hours of discontiation of anti-PD mediciation and iiii) after 14 hours of discontiation of anti-PD mediciation and 1 hour after intake of 100 mg sildenafil.

Official Title
-----------------
Motor Response to Acute Challenge to Sildenafil in Parkinsons Disease

Conditions
-----------------
Parkinsons Disease, Erectile Dysfunction

Intervention / Treatment
-----------------
* Drug: Sildenafil


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Men Parkinsons disease Erectile dysfunction previous tried sildenafil with beneficial effects on motor function Exclusion Criteria: psychosis Heart disease

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sildenafil<br>motor function to be tested before and after challenge with 100 mg sildenafil after taking normal anti-PD medication, and Again after discontinuation of anti-PD medication for 12 h | Drug: Sildenafil<br> <br> * Other names: Sildenafil (Viagra (R)) 100 mg;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Motor function | Motor function assessed by Unified Parkinsons disease Rating Scale, section 3 before and after challenge with Sildenafil and before and after discontinuation of anti-PD medication for 12 hours. | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cerebral Blood Flow (rCBF) | change in rCBF in basal ganglia from before to 1 hour after intake of 100 mg of sildenafil | 1 hour |