The rigidity seen in Parkinson's disease is due to
(D) Increased sensitivity of stretch reflex. > The hypokinetic features of Parkinson's disease are akinesia and bradykinesia, and the hyperkinetic features are rigidity and tremor. The absence of motor activity and the difficulty in initiating voluntary movements are striking.
Excessive simulation of alpha motor neurons of all the muscles.
Hypofunction of motor cortex.
Absence of cerebellar inhibition.
Increased sensitivity of stretch reflex.
Nervous System