What is a clonus response?
What is a clonus response?
Clonus is a type of neurological condition that creates involuntary muscle contractions. This results in uncontrollable, rhythmic, shaking movements. People who experience clonus report repeated contractions that occur rapidly. It’s not the same as an occasional muscle contraction.
How do you assess for ankle clonus?
The ankle clonus reflex is assessed by performing a rapid forced dorsiflexion of the foot and then holding slight tension on the foot in the dorsiflexed position. Rhythmic contractions of the gastrocnemius muscle resulting in plantar flexion of the foot indicate a normal response.
Are ankle clonus normal?
A few beats of ankle clonus can be normal in the first few weeks of life but sustained ankle clonus at any age is abnormal.
What causes foot clonus?
Everything you need to know. Clonus is a neurological condition that occurs when nerve cells that control the muscles are damaged. This damage causes involuntary muscle contractions or spasms. Clonus spasms often occur in a rhythmic pattern.
Why would you test for ankle clonus?
Clonus of the ankle results in repeated dorsiflexion of the ankle in response to brisk dorsiflexion of the foot. The test helps in differentiating between the involvement of the central nervous and peripheral nervous system.
What causes clonus?
Clonus results due to an increased motor neuron excitation (decreased action potential threshold) and is common in muscles with long conduction delays, such as the long reflex tracts found in distal muscle groups. Clonus is commonly seen in the ankle but may exist in other distal structures as well.
Is ankle clonus normal in infants?
Positioning the extremity is also important. As demonstrated in this baby, a crossed adductor can be seen at this age and still be normal but should not persist beyond 7 months of age. A few beats of ankle clonus can be normal in the first few weeks of life but sustained ankle clonus at any age is abnormal.
What does ankle clonus absent mean?
An absence of transient ankle clonus has been shown to indicate neurological compromise.
What is the cause of clonus?
Clonus causes large, noticeable movements that are very different from typical twitches. It is usually triggered by an automatic response to a stimulus. The reflex leads to uncontrollable shaky movements. Clonus occurs most frequently in the muscles that control the ankles and knees.
