Neuroanatomy: subthalamic nucleus: practice question

The best answer is A, Left subthalamic nucleus. Hemiballismus is caused by a small infarct or haemorrhage of the contralateral subthalamic nucleus, which normally excites the internal pallidum and so suppresses unwanted movements.

Substantia nigra degeneration produces parkinsonism with rigidity and tremor.

Caudate degeneration produces chorea, as in Huntington disease, not ballistic flinging.

A right subthalamic lesion would produce movements on the left side.

It tests Neuroanatomy: subthalamic nucleus in Anatomy. Loss of this drive disinhibits the thalamus and cortex. The lesion is on the opposite side to the flinging limbs.

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy questions on this site to test what stuck.

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.