What are hypoactive reflexes?
What are hypoactive reflexes?
Hypoactive or absent reflexes are commonly observed in association with lower motor neuron lesions. However, this is usually due to coexisting involvement of muscle spindle sensory afferent fibers within peripheral nerves or roots (Figure 2).
What is the Achilles reflex response?
The Achilles reflex is a monosynaptic stretch reflex similar to the patellar reflex. In the Achilles reflex, the hammer taps the Achilles tendon while the foot is dorsiflexed, and the foot, in response, should jerk toward the plantar surface. The Achilles reflex originates in the S1 and S2 nerve roots.
Why is the Achilles reflexes important in walking?
In particular, the Achilles tendon is a long tendon that is important for storing and releasing elastic energy during walking, and as such, plays an important role in metabolic energy saving, as it actually “spares” the muscle from performing a large part of the work (3).
What causes decreased tendon reflexes?
Peripheral neuropathy is today the most common cause of absent reflexes. The causes include diseases such as diabetes, alcoholism, amyloidosis, uremia; vitamin deficiencies such as pellagra, beriberi, pernicious anemia; remote cancer; toxins including lead, arsenic, isoniazid, vincristine, diphenylhydantoin.
What is bilateral clonus?
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 are the different types of reflexes?
There are two types of reflex arcs:the autonomic reflex arc, affecting inner organs, and the somatic reflex arc, affecting muscles.
What does no ankle reflex mean?
When reflex responses are absent this could be a clue that the spinal cord, nerve root, peripheral nerve, or muscle has been damaged. When reflex response is abnormal, it may be due to the disruption of the sensory (feeling) or motor (movement) nerves or both.
What is the normal response of the plantar reflex?
The normal plantar reflex consists of flexion of the great toe or no response. With dysfunction of the corticospinal tract, there is a positive Babinski sign, which consists of dorsiflexion of the great toe with an associated fanning of the other toes.
How does the Achilles reflex protect the body?
Trunk and leg muscles respond to support the body in its sudden change of position, and the head and eyes turn to look at the cause of the injury. All this happens while the person is becoming aware of the burning sensation. A reflex that protects the body from injury, as this one does, is called a nociceptive reflex.
How does the tendon reflex work?
The DTR is a monosynaptic reflex arc. It is monosynaptic because only two neurons are involved: a sensory and a motor neuron, with a single synapse. After the examiner taps the muscle’s tendon, the muscle fibers’ stretch is detected at the muscle spindle located within the muscle fibers.
What does clonus mean?
Clonus is involuntary and rhythmic muscle contractions caused by a permanent lesion in descending motor neurons. Clonus may be found at the ankle, patella, triceps surae, wrist, jaw, biceps brachii.
