To compare between Idiopathic PD versus Parkinson-Dementia complex using different modalities: Demographic, Clinical, genetic, Psychometric and electrophysiologically

Parkinson's disease (PD), is one of the commonest neurodegenerative disorders with a severe progressive course and major impact on patients' quality of life. The development of late-onset PD likely results from the interaction of genetic and environmental factors in the context of brain aging.

Although several environmental exposures have been implicated, evidence for their causal contributions is limited.

PD in Egypt is a rapidly emerging concern as prevalence rose by 40.7% between 1990 and 2016, one of the highest increases in the world. which influences us to dig further in the genetic basis behind the scenes leading to that leap.

Cognitive impairment in PD constitutes a major source of disease burden for patients and families, and has a significant negative effect on patients' quality of life. Cognitive impairment without dementia is designated as mild cognitive impairment of PD (PD-MCI), where the activities of daily living are grossly preserved, whereas dementia associated with PD is designated as PD-D.

Parkinson's disease dementia is a neurofibrillary tangle degeneration involving the deposition of Alzheimer-type tau, predominantly in the mesial temporal cortex, brainstem, and basal ganglia.

The prevalence of Parkinson's Disease Dementia (PD-D) in the general population aged 65 years and over was 0.3 to 0.5%, and 3 to 4% of patients with dementia in the general population were estimated to be due to PD-D.

Transcranial magnetic stimulation (TMS) is a noninvasive neurophysiological technique for assessing human motor cortical function. With TMS, the underlying motor cortex is stimulated by an electric current induced by a transient magnetic field, generated in response to the passage of a large current through the stimulating coil located on the patient's scalp.

Inclusion Criteria:

• All participants must fulfill the following inclusion criteria of UINTED KINGDOM bank criteria of PD Men or women of at least 50-80 years of age.
• Are reliable and willing to make themselves available for the duration of the study and are willing to follow up.
• Medically stable outpatients with confirmed diagnosis of idiopathic PD according to United Kingdom Brain Bank Criteria
• Clear written informed consent from each participant in the trial.
• Patients after at least 6 h free of parkinsonian drugs (off-state).
• For the Parkinson's Dementia Complex group, dementia must be evident through history taking or clinical examination

Exclusion Criteria:

• Pregnants, breastfeeding, or willing to be pregnant during the study.
• Presence of clinically significant medical or psychiatric condition that may increase the risk associated with the study
• Participation in any other type of medical research that may interfere with the interpretation of the study.
• Patients with severe motor disability (bed-ridden ) that may interfere with the study procedure.
• History of surgical or invasive intervention for Parkinson disease.
• Patients with history of seizures or epilepsy including history in a first degree relative or patients on treatment that reduce seizure threshold.
• For the Parkinson's Dementia Complex group, Subject with dementia due to other diseases or with Parkinson's dementia complex and contribution of other disorders (Mixed dementia)
• Brain imaging suggesting another diagnosis.

patients with parkinson's disease and parkinson dementia complex