What causes Hyperreflexia patellar reflex?

Asked By: Geovanni Weibels | Last Updated: 16th March, 2020
Category: medical health bone and joint conditions
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Hyperreflexia refers to hyperactive or repeating (clonic) reflexes. These usually indicate an interruption of corticospinal and other descending pathways that influence the reflex arc due to a suprasegmental lesion, that is, a lesion above the level of the spinal reflex pathways.

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Keeping this in view, what causes the patellar reflex?

The knee-jerk reflex, also known as the patellar reflex, is a simple reflex that causes the contraction of the quadriceps muscle when the patellar tendon is stretched. I describe the course of the reflex arc from muscle spindles in the quadriceps muscle to motor neurons that cause movement of the leg.

Similarly, what does exaggerated knee reflex indicate? Spasticity is stiff or rigid muscles. It may also be called unusual tightness or increased muscle tone. Reflexes (for example, a knee-jerk reflex) are stronger or exaggerated. The condition can interfere with walking, movement, speech, and many other activities of daily living.

Beside this, what does it mean when you have hyper reflexes?

Hyperreflexia is defined as overactive or overresponsive reflexes. Examples of this can include twitching or spastic tendencies, which are indicative of upper motor neuron disease as well as the lessening or loss of control ordinarily exerted by higher brain centers of lower neural pathways (disinhibition).

What nerve is responsible for the patellar reflex?

Although the knee jerk reflex is mediated by the L3 and L4 nerve roots, evidence exists that altered knee jerk expression may occur with exclusively L5 radiculopathy.

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What does it mean if your knee doesn't reflex?

Patellar tendon reflex.
Your doctor will use a rubber hammer to tap firmly on the tendon just below your kneecap. In a normal test, your knee will extend and lift your foot a little. A decreased or absent reflex may mean that there is compression in the L2, L3, or L4 region.

Why is the knee jerk reflex important?

Motor nerves in the spinal cord then conduct the impulse right back to the quadriceps, triggering a muscle contraction that makes you kick. What's the point of this reflex? When we stand upright, our muscles constantly stretch and contract slightly, just to keep us balanced. The knee jerk reflex is part of this system.

What does the knee reflex test show?

Exaggerated (brisk) deep tendon reflexes such as this can be found in upper motor neuron lesions, hyperthyroidism, anxiety or nervousness. The test itself assesses the nervous tissue between and including the L2 and L4 segments of the spinal cord.

Why do doctors tap your knee?

The most familiar reflex is the knee-jerk: when a doctor taps on the tendon below your knee with a reflex hammer and that leg kicks out. This communication, from a sensory nerve to the spinal cord and on to a motor (movement) nerve (without going to the brain), is known as a reflex arc.

Why do knees jerk?


Knee-jerk reflex, also called patellar reflex, sudden kicking movement of the lower leg in response to a sharp tap on the patellar tendon, which lies just below the kneecap. In reaction these muscles contract, and the contraction tends to straighten the leg in a kicking motion.

What part of the nervous system controls reflexes?

The central nervous system CNS is responsible for integrating sensory information and responding accordingly. It consists of two main components: The spinal cord serves as a conduit for signals between the brain and the rest of the body. It also controls simple musculoskeletal reflexes without input from the brain.

Is the knee jerk reflex somatic or autonomic?

Somatic reflexes include all those reflexes that involve stimulation of skeletal muscles by somatic division of the nervous system. An example of such a reflex is the rapid withdrawal of a hand from a hot object. Some reflexes are structurally and functionally simple, e.g., knee jerk reflex.

Is Hyperreflexia a sign of MS?

Hyperreflexia is a consequence of loss of inhibition from descending motor tracts. The Babinski's and Hoffmann's signs are special examples of loss of inhibition. Spasticity, which is a disorder of deep tendon reflex loops, is a companion of hyperreflexia.

What are brisk reflexes a sign of?

Brisk reflexes describe an instance where the muscles contract more strongly or more times than normal. If you have brisk reflexes, you might also have one or more of the following symptoms: gait (walking) problems. difficulty grabbing objects.

What is Hoffman's sign?


Hoffman's sign or reflex is a test that doctors use to examine the reflexes of the upper extremities. This test is a quick, equipment-free way to test for the possible existence of spinal cord compression from a lesion on the spinal cord or another underlying nerve condition.

How do you know if you have Hyperreflexia?

The symptoms of AD may include:
  • anxiety and apprehension.
  • irregular or racing heartbeat.
  • nasal congestion.
  • high blood pressure with systolic readings often over 200 mm Hg.
  • a pounding headache.
  • flushing of the skin.
  • profuse sweating, particularly on the forehead.
  • lightheadedness.

Are Hyperreflexia normal?

Definition. Autonomic dysreflexia or hyperreflexia (see also Chapter 114) is a syndrome of episodic autonomic hyperactivity in the setting of spinal cord injury. The syndrome is more common in complete spinal cord injuries, with no sensation or motor function below the level of the lesion.

Why do doctors test reflexes?

Reflex tests are performed as part of a neurological exam, either a mini-exam done to quickly confirm integrity of the spinal cord or a more complete exam performed to diagnose the presence and location of spinal cord injury or neuromuscular disease. Deep tendon reflexes are responses to muscle stretch.

How can I improve my reflexes?

Seven ways to improve your reflexes
  1. Pick a sport, any sport – and practise. What exactly do you want to improve your reflexes for?
  2. Chill out. Your reaction time is always going to be slower if you're too tense.
  3. Eat a lot of spinach and eggs.
  4. Play more videogames (no, really)
  5. Use your loose change.
  6. Playing ball.
  7. Make sure you get enough sleep.

What does no reflexes in legs mean?


The normal response is a 'knee jerk'. This is an example of a reflex, which is an involuntary muscular response elicited by the rubber hammer tapping the associated tendon. When reflex responses are absent this could be a clue that the spinal cord, nerve root, peripheral nerve, or muscle has been damaged.

How does the knee jerk reflex protect the body?

Reflexes protect your body from harmful things. It's also called the deep tendon reflex (DTR), because the doctor actually is tapping on your patellar tendon. The tap on the tendon stretches the tendon, which in turn stretches the thigh muscle connected to it.

What is clonus a sign of?

Clonus is a series of involuntary, rhythmic, muscular contractions and relaxations. Clonus is a sign of certain neurological conditions, particularly associated with upper motor neuron lesions involving descending motor pathways, and in many cases is, accompanied by spasticity (another form of hyperexcitability).