Clonus Assessment in Preeclampsia

Aug 6, 2025

Overview

This lecture demonstrates how to check for ankle clonus, especially in the context of preeclampsia, to assess neurological status and seizure risk.

Importance of Clonus Assessment in Preeclampsia

  • Clonus and hyperreflexia are signs of central nervous system irritability in preeclampsia.
  • Presence of clonus indicates increased seizure risk.

Steps for Checking Ankle Clonus

  • Have the patient sit with feet dangling.
  • Support the lower leg of the foot you want to test.
  • Quickly dorsiflex (bend upward) the foot.
  • Observe the foot's response after releasing.

Interpreting Clonus Results

  • A normal (negative) clonus: foot returns to normal position without rhythmic movements.
  • A positive clonus: foot rhythmically bounces or beats three or more times after dorsiflexion.

Key Terms & Definitions

  • Preeclampsia — A pregnancy complication characterized by high blood pressure and signs of organ damage.
  • Hyperreflexia — Overactive reflexes, often seen in neurological conditions.
  • Clonus — Rhythmic, involuntary muscle contractions and relaxations, usually observed by quickly dorsiflexing the foot.
  • Dorsiflexion — Movement that brings the top of the foot toward the shin.

Action Items / Next Steps

  • Practice clonus assessment technique as demonstrated.
  • Review additional lectures in the maternity series for further learning.