A basal ganglia lesion causing parkinsonism most commonly presents with which symptom?

A basal ganglia lesion causing parkinsonism most commonly presents with which symptom?

• A. Hyperreflexia.
• B. Bradykinesia and rigidity.
• C. Seizures.
• D. Nystagmus.

Answer: (B)

Basal ganglia dysfunction in parkinsonism disrupts starting and scaling voluntary movements. When dopaminergic input from the substantia nigra is lost, the balance shifts toward reduced facilitation and increased inhibition of movement, producing slowness and stiffness. Bradykinesia, the prominent slowing of movement, together with rigidity (increased muscle tone), are the hallmark motor features of this condition. Tremor can occur but is not as universally present as the combination of slowed movement and rigidity. Hyperreflexia points to upper motor neuron involvement, seizures reflect cortical hyperexcitability, and nystagmus comes from eye movement control circuits outside the basal ganglia.

Basal ganglia dysfunction in parkinsonism disrupts starting and scaling voluntary movements. When dopaminergic input from the substantia nigra is lost, the balance shifts toward reduced facilitation and increased inhibition of movement, producing slowness and stiffness. Bradykinesia, the prominent slowing of movement, together with rigidity (increased muscle tone), are the hallmark motor features of this condition. Tremor can occur but is not as universally present as the combination of slowed movement and rigidity. Hyperreflexia points to upper motor neuron involvement, seizures reflect cortical hyperexcitability, and nystagmus comes from eye movement control circuits outside the basal ganglia.