Jendrassik maneuver

Q: What is Jendrassik maneuver in neurological exam?

Answer: Maneuver to enhance the neurological reflexes.

During a complete neurological exam, eliciting biceps, triceps, brachioradialis, knee (patellar), and ankle (Achilles) reflexes is standard practice. If a patient's reflexes can't be easily elicited, they can be amplified by the Jendrassik maneuver.

The Jendrassik maneuver involves asking the patient to clench their teeth. To test lower extremity reflexes, the patient is asked to hook together the flexed fingers of both hands and pull. 

The physiology behind this mechanism is described as follows: "A weak or apparently missing reflex could be triggered by afferent activity resulting from such muscle tension. This is the true explanation for the maneuver, not a diversion of the patient’s attention—a misconception that can be heard even today."

It was described first in the late 19th century by a Hungarian physician, Ernő Jendrassik.

Video link: https://youtu.be/MyQ23ZlL8Iw?feature=shared

 

#neurology

#physical-exam

References:

1. Ertuglu LA, Aydin A, Kumru H, Valls-Sole J, Opisso E, Cecen S, Türker KS. Jendrassik maneuver effect on spinal and brainstem reflexes. Exp Brain Res. 2019 Dec;237(12):3265-3271. doi: 10.1007/s00221-019-05668-y. Epub 2019 Oct 24. PMID: 31650212.

2.  Pásztor, E. (March 1, 2004). "Erno Jendrassik (1858?1921)". Journal of Neurology. 251 (3): 366–367