neurologic disorders
Numbness
Key Points
Use an open-ended question to ask patients to describe their numbness. The anatomic pattern and time course of symptoms helps narrow the list of possible diagnoses. If part of a limb is numb, suspect a peripheral nerve, plexus, or nerve root lesion. If both limbs are numb on one side, with or without numbness of the trunk on the same side, suspect a brain lesion. If patients have bilateral numbness below a specific spinal cord segment, particularly with motor and reflex deficits, suspect a transverse myelopathy. If patients have bilateral numbness not corresponding to a spinal cord segment, suspect a polyneuropathy, multiple mononeuropathy, or a patchy spinal cord or brain lesion. If numbness occurs in a stocking-glove distribution, suspect an axonal polyneuropathy. If numbness occurs nearly instantaneously in the absence of trauma, suspect an acute ischemic event. Consider doing electrodiagnostic testing for suspected peripheral nervous system causes and MRI for CNS causes. 