A 23-year-old man visits the emergency room. Upon awakening that morning, he noticed that his right hand was paralyzed.
Physical examination shows he is unable to extend his hand and fingers, otherwise his sensibility and strength are normal. His deep tendon reflexes are normal with plantar reflexes. He has no relevant medical history.
Paralyzed right hand
I. van Schaik & T. van Trier
The patient has a compression of the radial nerve, leading to a ‘dropping hand’. The typical patient has fallen asleep in a chair with his arm over a chairback after a night of drinking (saturday night palsy) or with a partner’s head lying on the upper arm (paralyse d’amour), compressing the radial nerve proximal in the upper arm. Because the radial nerve is mainly a motor nerve, there are hardly sensory symptoms. In case of an acute compression, a wait-and-see policy is sufficient and prognosis is excellent.
When asked, the patient confirms that his girlfriend slept overnight. After two weeks, his strength has fully recovered.
Why the other ones are not correct:
- ALS may present with slowly progressive atrophy and weakness of hand muscles which may start asymmetrically. However, extensor and flexor muscles are equally involved and the onset is never as abrupt as in this case.
- MS may start with weakness in one limb but this is rare and you would expect to find abnormalities indicating central nervous system involvement, such as increased deep tendon reflexes and a Babinski sign. Often, the first signs of MS are non-specific symptoms as fatigue, dizziness and sensory abnormalities.
- Carpal tunnel syndrome, you would expect a patient to complain mainly of sensory disturbances and to find sensory abnormalities if any. In case of motor involvement, the m. abductor pollicis brevis may be weak and atrophic, but strength should be normal otherwise.
With C7 radiculopathy You would expect pain radiating from the neck, shoulder to the hand, especially to the middle finger. Furthermore, in case of a C7 radiculopathy the triceps reflex is lower and the m. triceps is expected to be weak.