NeuroLogic Exam - MCQs

With a lesion of the corticospinal tract the greatest deficit will be noted in which one of the following areas?

A. The foot.
B. The hand.
C. The shoulder girdle muscles.
D. The pelvic girdle muscles.
E. The axial muscles.

Answer / Explanation:


The correct answer is B.

The hand has a large cortical representation in the precentral gyrus and the anterior horn cells that innervate the hand receive almost exclusive input from the lateral corticospinal tract while more proximal and axial muscles also receive input from the indirect brainstem motor control centers so deficits are not as great in these muscle groups.