Dr. Wells presented an interesting case of a man who presented with bilateral, symmetric, progressive, ascending lower extremity numbness that turned out to be secondary to compressive myelopathy from a benign lipomatous growth.
Step one: Localize the lesion:
Examine their sensation to light touch, sharp stimuli, proprioception, vibration and temperature
Vibration and proprioception live in the DORSAL COLUMN
Temperature and pain sensation live in the SPINOTHALAMIC TRACT
Step two: Determine the pattern of sensory loss:
If it’s one limb: think peripheral nerves/mononeuropathy, nerve plexus or a spinal root
If it’s bilateral or symmetric, think polyneuropathy or spinal cord lesion
If only one side is affected, think higher up (ie brainstem and above) and on the contralateral side.
Our patient here ended up having compressive myelopathy of T7-T10 which can be very difficult to localize. Dr. Sullivan gave us a pearl about how to test thoracic reflexes #Sullivanpearls: Superficial abdominal reflexes! Here’s a video: