Q&A

What is the significance of ankle clonus?

What is the significance of ankle clonus?

Therefore, clonus is used as part of the neurological physical exam to evaluate the status of a patient’s nervous system. It can be evaluated in many joints but is most commonly seen in the ankle joint by briskly dorsiflexing the foot.

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.

What does beats of clonus mean?

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.

What does the presence of clonus indicate?

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. Symptoms are common in a few different muscles, especially in the extremities.

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.

When Should ankle clonus be diagnosed?

Rhythmic contractions of the gastrocnemius muscle result in repetitive plantar flexion of the foot. Compared with the wakeup test, the ankle clonus test can usually be elicited before the patient regains consciousness, at a deeper level of anesthesia.

Why would you get 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.

What does a positive ankle clonus test mean?

The therapist holds the ankle in dorsiflexion. The initial brisk dorsiflexion and sustained pressure can be done with slight eversion of the foot. A positive Clonus sign is recorded when the examiner feels and sees the oscillations against this pressure. Rhythm and number of beats can be appreciated.

Is ankle clonus ever normal?

Diagnosis. Clonus at the ankle is tested by rapidly flexing the foot into dorsiflexion (upward), inducing a stretch to the gastrocnemius muscle. Subsequent beating of the foot will result, however only a sustained clonus (5 beats or more) is considered abnormal.

What causes the clonus of the ankle test?

Clonus is a rhythmic, oscillating, stretch reflex. The cause of the oscillations are related to lesions in upper motor neurons and is generally accompanied by hyperreflexia.

Why is clonus a sign of a neurological condition?

Significance of clonus is that it is a sign of neurological conditions, epecially associated with upper motor neuron lesions involving descending motor pathways Clonus is a condition that produce involuntary muscle spasms and most commonly it affects the muscles at the end of a limb.

How is clonus used in the medical field?

Introduction Clonus is a rhythmic, oscillating, stretch reflex, the cause of which is not totally known; however, it relates to lesions in upper motor neurons and therefore is generally accompanied by hyperreflexia.   Therefore, clonus is used as part of the neurological physical exam to evaluate the status of a patient’s nervous system.

When does The Clonus of the ankle fade away?

Ankle clonus consists of a series of rhythmic alternating flexions and extensions of the ankle. Unsustained clonus fades away after a few beats, sustained clonus may persist as long as the examiner continues to hold slight pressure against the sold of the foot.