| Westphal's sign | |
|---|---|
 | |
| Patellar tendon reflex arc | |
| Differential diagnosis | Peripheral nerve disease, Motor cortex lesion |
Westphal's sign is the clinical correlate of the absence or decrease of patellar reflex or knee jerk. Patellar reflex or knee jerk is a kind of deep or stretch reflex where an application of a stimulus to the patellar tendon such as strike by a solid object or hammer caused the leg to extend due to such stimulus causes the quadriceps femoris muscle to contract.
It is named for Karl Friedrich Otto Westphal (1833-1890).
Associated conditions
Westphal's sign has a clinical significance used in determining neurodisorders or diseases such as:
- receptor damage, peripheral nerve disease, involving the dorsal(sensory) columns of the spinal cord and cerebellar lesions
- lesions present within the motor cortex of the brain or the pyramidal tracts which it combined with muscular spasms
- complete interruption of sensory and/or motor impulse transmission in the femoral nerve
- Jensen, David Ph.D. (1976). The Principles of Physiology. New York: Appleton-Century-Crofts.