The Stanford 25

An Initiative to Revive the Culture of Bedside Medicine

Deep Tendon Reflexes

Introduction: Reflexes are useful for the general internist to perform, but you can’t evaluate them if

  1. You don’t have a hammer.
    • (Stanford interns who don’t have a hammer, are to see Dr. AV, who’ll get you one. If you have a Taylor (Tomahawk) hammer, he’ll be pleased to dispose of that for you.)
  2. You don’t use proper technique, in which case the reflex will appear to be absent when it is present.
  3. If you don’t know what abnormalities to expect and what they mean.

The ankle reflex in a bedridden patient should serve as a barometer of your technique: it requires positioning the patient well and good technique. If you can do that, you can do the other reflexes.

The video below begins with the ankle reflex obtained with the patient kneeling on a chair.  It is rare to find a hospitalized patient who can do that for you, and so you must know one of the three other ways of doing it demonstrated in the video.

Technique:

DTR scale

I am not a big believer in grading reflexes (grading muscle power is much more useful). Nevertheless, if you need something beyond “absent,” “present,” “brisk,” or “hyperactive” then use below. If you have a hyperactive reflex don’t forget to look for clonus.

  • 0: absent reflex
  • 1+: trace, or seen only with reinforcement
  • 2+: normal
  • 3+: brisk
  • 4+: non-sustained clonus
  • 5+: sustained clonus

There is no point doing the reflexes if you don’t know the root level, so memorize the numbers.

  • Biceps and Brachioradialis  C5 & 6
  • Triceps C6 & 7
  • Patellar L2, 3, & 4
  • Ankle S1

The SUPERFICIAL reflexes include the

  • Corneal
  • Abdominal
    • Significant if asymmetric–usually signifies a UMN lesion on the absent side.
  • Cremaster
  • The PLANTAR. The plantar reflex can be
    • Normal
    • Absent
    • Or replaced by an abnormal reflex termed the BABINSKI response.
      • It is incorrect to say ‘negative Babinski’your choices are ‘normal’ or ‘absent’ or ‘Babinski Response.’

Embedded Videos & Links (Not produced by Stanford, click through for credit and source).

Excellent normal DTR exam with text via U of Toronto (quicktime, embedding impossible).

Ankle Clonus: suggests UMN disease

Knee Clonus: suggests UMN disease

Fasciculations–suggest LMN disease or denervation

Babinski Response

Advertisements

Written by stanford25admin

June 7, 2010 at 3:07 pm

%d bloggers like this: