Abstract
Parkinson disease (PD) is recognized as one of the most common neurologic disorders, affecting approximately 1% of individuals older than 60 years. Onset of motor signs in PD is typically asymmetric, with the most common initial finding being an asymmetric resting tremor in an upper extremity.
Over time, patients notice symptoms related to progressive bradykinesia, rigidity, and gait difficulty. Many patients with PD have some executive function impairment, even early in the disease.
Substantial cognitive impairment and dementia typically occur 8 years or more after the onset of motor features. Patients with PD also frequently suffer from various behavioral disorders.
In the chapter we describe two typical cases of cognitive deficit in patients with PD.