Which neurological disorder is characterized by tremors and rigidity?

Parkinson's disease is characterized by the presence of tremors and rigidity, which are hallmark symptoms of this neurological disorder. The tremors often begin as a resting tremor, which typically affects the hand or fingers, and is commonly described as a "pill-rolling" movement. Rigidity refers to the stiffness in the limbs and neck, which makes movements difficult and uncomfortable.

These symptoms occur due to the degeneration of dopamine-producing neurons in the brain, particularly in an area called the substantia nigra. This loss of dopamine leads to impaired coordination and control of voluntary movements, which is why individuals with Parkinson's disease often experience difficulties with balance, posture, and fine motor activities.

In contrast, Alzheimer's disease primarily affects memory and cognitive function, not typically presenting with tremors or rigidity. Similarly, multiple sclerosis is characterized by symptoms related to the central nervous system, including weakness and coordination issues, rather than the specific motor symptoms seen in Parkinson's. Huntington's disease is associated with chorea (involuntary movements), cognitive decline, and psychiatric symptoms, rather than the tremor and rigidity profile seen in Parkinson's disease.