Quote:
Originally Posted by Superman
But if someone reports numbness from the wrist down, nerve problems will not explain that.
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Yes and no. The median nerve (involved in carpal tunnel syndrome) innervates the thumb, index finger, middle finger, and radial half of the ring finger. The ulnar nerve (involved in cubital tunnel syndrome) innervates the ulnar half of the ring finger and the small finger. So purely anatomically, you're correct that glove-like paresthesia is anatomically unlikely. (Of course, that doesn't take into account the 15% of people that have Martin-Gruber anastamoses between the median and ulnar nerves in the hand. Maybe those people don't follow the perfect dermatomal distributions expected from textbooks.)
But (here's the "no" part of my response) patients are often not savvy enough to present with a complaint of which fingers, specifically, go numb. They just know their hand(s) goes numb. Now, upon questioning and examining the patient they may then realize that some fingers seem to bother them more than the others. But that's not always present, whether it's because the diseases didn't read the textbook and present in typical fashion, or because the patient isn't discriminatory enough to realize that only part of the hand is actually symptomatic.
The history sometimes helps. Carpal tunnel very typically presents itself at night, for example. Exam helps. Which fingers go numb? Is there a Tinel's sign at the wrist? Or at the elbow? Is there a Phalen's sign, Durkan's sign, or flexed elbow sign on exam? Is there any dryness to the skin of the fingers? Is there any hand atrophy? Are there any symptoms when the neck is placed through a range of motion? And usually electrodiagnostic studies (EMG/NCV) of the upper extremities are obtained to help confirm the diagnosis.