Westphal's sign

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|image = Patellar-knee-reflex.png

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|caption = Patellar tendon reflex arc

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|differential = Peripheral nerve disease, Motor cortex lesion

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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.{{citation needed|date=August 2021}}

It is named for Karl Friedrich Otto Westphal (1833–1890).{{WhoNamedIt|synd|945}}{{cite book|author=C. F. O. Westphal|title=Über einige durch mechanische Einwirkung auf Sehnen und Muskeln hervorgebrachte Bewegungs-Erscheinungen|publisher=Archiv für Psychiatrie und Nervenkrankheiten|location=Berlin|year=1875|volume=5|pages=803–834}}

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Associated conditions

Westphal's sign has a clinical significance used in determining neurological disorders or diseases such as:{{citation needed|date=August 2021}}

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{{clarify|date=September 2011}}
complete interruption of sensory and/or motor impulse transmission in the femoral nerve

References

{{cite book|title=The Principles of Physiology|author=Jensen, David Ph.D.|publisher=Appleton-Century-Crofts|location=New York|year=1976}}

Category:Symptoms and signs: Nervous system

Category:Examination of the knee