A 76-week prospective, open-label, multicenter study to evaluate the long-term effect of Exelon® capsule and transdermal patch on worsening of the underlying motor symptoms of PD in patients with mild to moderately severe dementia associated with Parkinson's disease (PDD).

1. 50-80 years of age (both inclusive);
2. males, and females not of child-bearing potential (surgically sterile or one year
postmenopausal);
3. have a clinical diagnosis of idiopathic Parkinson*s disease according to the UK
Parkinson*s Disease Society Brain Bank clinical diagnostic criteria (see Appendix 2);
4. have a clinical diagnosis of Parkinson*s disease dementia according to DSM-IV
criteria (Code 294.1) (see Appendix 3), with onset of symptoms of dementia at least 2 years after the first diagnosis of idiopathic Parkinson*s disease;
5. have a MMSE score of * 10 and * 24 (at Screening Visit only, Visit 1);
6. have sufficient education to have been able to read, write, and communicate
effectively during the premorbid state;
7. be cooperative and willing to complete all aspects of the study, and capable of doing so, either alone or with the aid of a responsible caregiver, according to judgment of the investigator;
8. be residing with someone in the community throughout the study or, if living alone, in regular contact with the primary caregiver;
9. have a single caregiver, paid or unpaid, willing to accept responsibility for supervising the treatment, (e.g. application and removal of the patch daily at approximately the same time of day) and assessing the condition of the patient throughout the study, and for providing input to safety and efficacy assessments in accordance with all protocol requirements;
10. provide, if mentally competent (or if incompetent, their legally acceptable
representative will provide) written informed consent prior to their participation in the study. Caregivers also will provide written informed consent.

1. an advanced, severe, or unstable disease of any type that may interfere with the
primary and secondary variable evaluations;
2. a score of 5 in the *on*-state on the Modified Hoehn and Yahr Staging (UPDRS Part V) assessment at screening;
3. a current diagnosis of any primary neurodegenerative disorder other than idiopathic PD e.g. Alzheimer*s disease, Frontotemporal dementia, Huntington*s disease, Dementia with Lewy bodies, Parkinson-Plus-Syndromes other than PDD (e.g. progressive supranuclear palsy or olivopontocerebellar degeneration);
4. a current diagnosis of any treatable dementia (hypothyroidism, syphilis, vitamin B12 or folate deficiency, hydrocephalus, chronic subdural hematoma) that is verified by the investigator to be the cause of dementia. Patients receiving stable therapy for hypothyroidism, vitamin B12 and folate deficiency, not considered to be the cause of dementia by the investigator, may be enrolled. Patients with abnormal laboratory diagnostic tests at screening not previously documented or further investigated are not eligible for enrollment;
5. a current diagnosis of probable vascular dementia according to the National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l*Enseignement en Neurosciences criteria (NINDS-AIREN) criteria (see Appendix 4);
6. a current diagnosis of a major depressive episode according to DSM-IV criteria (Code 296) (see Appendix 5), or any other DSM-IV Axis I diagnosis that may interfere with the response of the patient to study medication, including bipolar disorder or schizophrenia, as assessed by psychiatric evaluation. Patients with major depression at baseline who are clinically stable under therapy may be enrolled;
7. a current diagnosis of active, uncontrolled seizure disorder;
8. a disability that may prevent the patient from completing all study requirements and, in particular, interfere with the assessment of dementia (e.g., blindness, deafness, severe extrapyramidal symptoms during the *on*-state);
9. a history of stereotaxic brain surgery for Parkinson*s disease (e.g. pallidotomy, deep brain stimulation, tissue transplant);
10. a current diagnosis or ECG, at screening or baseline, that displays evidence of
bradycardia (<50 bpm), sick-sinus syndrome, conduction defects (sino-atrial block,
second or third degree atrio-ventricular block);
11. a current diagnosis of acute, severe, or unstable asthmatic conditions;
12. a clinically significant urinary obstruction;
13. a current diagnosis of active, uncontrolled peptic ulceration or gastrointestinal
bleeding within the last 3 months;
14. elevated liver function tests, specifically elevated alkaline phosphatase (AP), ALT
(SGPT), AST (SGOT), or gamma-glutamyl-transferase (GGT) greater than 3 times the
upper limit of the normal range;
15. a known exaggerated pharmacological sensitivity or hypersensitivity to drugs similar to Exelon® or to other cholinergic compounds;
16. patients receiving antipsychotics who are not on stable doses of atypical antipsychotics for four weeks prior to baseline;
17. patients who have previously participated in any clinical study with anti-dementia drugs;
18. taken any of the following substances during the four weeks prior to randomization:
* cholinesterase inhibitors or cholinergic drugs (e.g., rivastigmine, donepezil,
tacrine, galantamine, succinylcholine-type muscle relaxants). Topical pilocarpine
will be permitted.
* centrally-acting anticholinergic drugs, including tricyclic and tetracyclic
antidepressants
* neuroleptics other than clozapine or quetiapine
* lithium
* paroxetine
* memantine
* an investigational drug
* a drug or treatment known to cause major organ system toxicity
Note: Stable patients on cholinesterase treatment and/or memantine should not be washed out in order to enter the study. However, if patients are on these medications and in the investigator's clinical judgment, there is a legitimate medical reason for discontinuation (i.e., side effect profile, lack of benefit), then it would be appropriate for these patients to undergo the 4-week wash-out period, in order to enter the study.
19. started any new, or change in dose during the four weeks prior to randomization:
* psychotropic medication (clozapine, quetiapine, antidepressants, anxiolytics or
hypnotics including benzodiazepines, anticonvulsants);
* anti-parkinsonian medication;
* peripheral anticholinergic drugs: If new-onset urinary urgency or urinary
incontinence constitutes a major problem which cannot be adequately managed
with non-pharmacological measures, then initiation of treatment with a peripheral
anticholinergic drug such as tolterodine or oxybutynin will be permitted.