Final answer:
Parkinson's disease is an age-related neurocognitive disorder characterized by neural atrophy. It causes the loss of dopamine neurons in the midbrain, resulting in symptoms such as tremors, slowed movement, speech changes, and rigid muscles. The disease is eventually fatal.
Step-by-step explanation:
Parkinson's disease is a type of age-related neurocognitive disorder characterized by neural atrophy and the abnormal byproducts of that atrophy; it is eventually fatal. The disease causes the loss of dopamine neurons in the substantia nigra, a midbrain structure that regulates movement. This loss of neurons leads to symptoms such as tremors, slowed movement, speech changes, balance and posture problems, and rigid muscles. Over time, these symptoms progressively worsen and can also include psychological symptoms.