The Neurological Examination and Diagnostic Tests
An 85-year-old man is being evaluated for gait difficulties. He says that he frequently trips walking upstairs or on uneven surfaces. On examination, it is found that joint proprioception is absent in his toes, but present at the ankles. People with impaired position sense will usually fall if they simultaneously stand with their feet together and do which of the following?
b. Extend their arms in front of them
The answer is e. Standing with the feet together and the eyes closed is the Romberg test. The person with poor position sense needs visual cues to remain standing. This test was introduced as a helpful way to check for deficits associated with tabes dorsalis, a form of neurosyphilis. In tabes dorsalis, the dorsal columns of the spinal cord are damaged. These dorsal or posterior columns carry the nerve fibers that transmit vibration and position sense to the brain. With the widespread use of penicillin, tabes dorsalis has become rare in industrialized nations, and impaired position sense is much more likely to be a consequence of diabetes mellitus, spondylosis, or alcoholism. In performing the test, it is important to remember that even normal people will tend to sway slightly with their eyes closed, and that those with loss of cerebellar function or vestibulopathy will also sway more with loss of visual cues.
A 62-year-old right-handed man has “involuntary twitches” of his left hand. Over the past 6 to 12 months he has noticed that his left hand shakes at rest. He can stop the shaking by looking at his hand and concentrating. The shaking does not impair his activities in any way. He has no trouble holding a glass of water. There is no tremor in his right hand, and the lower extremities are not affected. He has had no trouble walking. There have been no behavioral or language changes. On examination, a left hand tremor is evident when he is distracted. Handwriting is mildly tremulous. He is very mildly bradykinetic on the left. The most likely examination finding would be which of the following?
a. Upper motor neuron pattern of weakness on the left
b. Lower motor neuron pattern of weakness on the left
c. Bilateral upper motor neuron pattern of weakness
d. Mild cogwheel rigidity on the left only with distraction