Which movement disorder is due to insufficient dopamine production?

• A. Epilepsy
• B. Parkinson Disease
• C. Glaucoma
• D. Poliomyelitis

Answer: (B)

Movement relies on dopamine in the brain’s basal ganglia circuits to regulate and refine voluntary movement. When dopamine-producing neurons, especially in the substantia nigra, are lost or not functioning well, the balance of motor commands shifts toward the pathways that inhibit movement. This leads to the characteristic slowing, stiffness, tremor, and reduced spontaneity seen in Parkinson disease. In this condition, insufficient dopamine production in the nigrostriatal pathway disrupts motor control, which is why Parkinson disease is the movement disorder described.

Epilepsy involves abnormal electrical activity in the brain, not a dopamine shortage. Glaucoma is an eye condition related to increased intraocular pressure and optic nerve damage. Poliomyelitis is a viral infection that damages motor neurons.