Absence of tendon reflexes
Symptom Description:
The absence of tendon reflexes, also known as areflexia, is the clinical finding where no response is elicited when a tendon is tapped with a reflex hammer. Normally, this action would cause a quick muscle contraction. Tendon reflexes are tested at various points in the body, including the Achilles tendon, the patellar tendon (knee jerk), the biceps, and the triceps. The absence of these reflexes can suggest a dysfunction of the peripheral nervous system, which may be due to several reasons:
- Peripheral Neuropathy: Often caused by diabetes, vitamin deficiencies, or toxic exposures.
- Neuromuscular Junction Disorders: Such as myasthenia gravis.
- Spinal Cord Injuries: That affect the specific segments of the spinal cord associated with the reflex arcs.
- Certain Neurodegenerative Conditions: Such as Guillain-Barré syndrome or amyotrophic lateral sclerosis (ALS).
Importance in Diagnosis:
The absence of tendon reflexes can be a critical indicator of underlying neurological conditions and warrants further investigation through detailed neurological examinations and appropriate imaging or laboratory tests.
Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology