Ankle jerk reflex
The ankle jerk reflex, also known as the Achilles reflex, occurs when the
Root value
This reflex is mediated by the S1 spinal segment of the spinal cord.[1]
Procedure and components
Ankle of the patient is relaxed. It is helpful to support the ball of the foot at least somewhat to put some tension in the Achilles tendon, but don’t completely
Absent ankle jerk
The Achilles
Common causes
- Lumbar herniated disk syndrome
- Lumbar spinal stenosis
- Endocrinedisorders
- Sciatic neuropathy
- Lumbosacral plexus disorder
- Amyotrophic lateral sclerosis
- Cauda equina syndrome
- Lumbar radiculopathy
- Holmes-Adie syndrome
- Idiopathic
- Trauma
- Hypothermia
- Infectious diseases
- Tabes dorsalis
- Poliomyelitis, acute
- Lumbar disk infection/pyogenic
- Arachnoiditis lumbosacral
- Neoplasticdisorders
- Primary
- Secondary
- autoimmune diseases
- Diabetic neuropathy
Rarer causes
- Abetalipoproteinemia
- Electrolyte abnormalities
- Deficiency disorders
- Vitamin E deficiency
- Congenital developmental disorders
- Genetic disorders
- Drugs
- Tubocurarine
- Pyridoxine excess/megadose
- Chronic alcoholism[4]
Ankle clonus
Grade 4 ankle hyperreflexia is called ankle clonus. There is repetitive ankle dorsiflexion and plantarflexion on passive dorsiflexion of the foot by the examiner till the force applied by the examiner is withdrawn.
Causes
Any spinal cord lesions, be it traumatic, neoplastic, pyogenic, vascular above the level of S1 can cause clonus. This is because of the spasticity caused by the UMN type of injury causing hyperreflexia and clonus. Some other causes of clonus are
See also
References
- ^ "Medscape- Neurologic examination". Retrieved 6 February 2013.
- PMID 21250237. Retrieved 18 July 2017.
- ISBN 978-1-60547-239-3. Retrieved 4 July 2011.
- ^ "Diagnosis". Archived from the original on 9 June 2014. Retrieved 6 February 2013.