Which of the following is the expected neurological symptoms that this patient will mostly have in her left hand?
A 16-year-old teenage patient comes to the clinic complaining of episodes of sharp pain in her left upper limb. The pain started gradually a few months ago and has become progressively worse, especially after physical activity. She describes her pain as “someone stabbing me in my arm and then the pain moves down to my hand”. She is also complaining of some vision problems in her left eye. Her vital signs are normal. On physical exam she is normal in posture and her appearance is appropriate with her age. Both of her upper limbs are symmetrical. Palpation of her left upper limb shows tenderness mainly near hear neck. A mild ptosis is noticed on her left eyelid with anisocoria of her left pupil measuring 1 mm smaller than the right pupil. The right upper limb is normal. An X-ray and an MRI are ordered (shown in the exhibit). A. Numbness over her left thumb B. Numbness over the dorsum of her left hand C. Numbness over her index finger D. Numbness over her left little finger
Correct answer D: The patient in this case is suffering from thoracic outlet syndrome mostly due to a cervical rib (white arrows in the X-rays), which causes compression over the lower part of her brachial plexus (C8 and T1) leading to weakness and numbness in the ulnar nerve distribution, thus she will mostly have numbness in her little finger.
Numbness over the left thumb, numbness over the index finger (option C) and numbness over the thenar area (option E) are all related to compression of the median nerve not the ulnar nerve.
