The Most Important Neurologic Reflex

Purdy presents the case of a 56-year-old woman, who was admitted for back surgery. She had a long history of low back pain with an unchanging radiation of pain down the lateral aspect of her right leg to the foot. The neurology department was consulted, which found a motor weakness distally in the right lower limb and no major reflex changes other than an "up-going toe" on the right. A lacunar infarction of the left internal capsule was found in another scan that was done of the patient's head. This case seemed like a fairly straightforward L4-L5 lateral disc with L5 root involvement resulting in the motor weakness. The weakness noted could be due to an L5 root involvement or even a peroneal palsy; however, sometimes it is forgotten that an upper motor neuron or pyramidal tract lesion can present the same way.