Perform the Romberg test, which primarily tests position sense. To do this, ask the patient to stand with his feet together. Normally, he should be able to maintain this posture with his eyes open, indicating intact cerebellar function.
Now have the patient do the same thing for 20 to 30 seconds with his eyes closed. His posture should remain steady with only minimal swaying, indicating intact position sense. If the patient maintains this posture with his eyes open but not with his eyes closed, he has a positive Romberg test. Now check for pronator drift. To do this, ask the patient to hold his arms forward and parallel with the palms up and to close his eyes for 20 to 30 seconds.
Normally, the patient can maintain this position. but watch for downward drifting of one arm and pronation of the forearm, which suggest mild hemiparesis. Stay just as you are. Finally, ask the patient to keep his arms up and eyes closed while you tap the arms briskly downward.
Normally, the patient's arms return smoothly to the horizontal position.