What are brisk reflexes?
Brisk reflexes refer to an above-average response during a reflex test. During a reflex test, your doctor tests your deep tendon reflexes with a reflex hammer to measure your response. This test is often done during a physical exam. Quicker responses may lead to a diagnosis of brisk reflexes.
During a reflex test, your muscle shortens (contracts) in response to deep tendon taps from the reflex hammer. 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
- difficulty swallowing
- muscle aches and spasms
- slurred speech
Brisk reflexes may develop when neurons deteriorate. These neurons are also known as the upper motor nerve cells.
Other causes of brisk reflexes are associated with neurological conditions, including:
- Hyperthyroidism: This condition can cause too much thyroid hormone to be released in your body. This can cause the muscle fibers to break down too quickly, causing brisk reflexes.
- Anxiety: The adrenaline rushes caused by anxiety can cause your reflexes to be more responsive than normal.
- Lou Gehrig’s disease, or amyotrophic lateral sclerosis (ALS): Brisk reflexes are common with ALS. This nervous system disorder develops when your body attacks its own neurons and affects movement.
- Multiple sclerosis (MS): While weak reflexes are more common with MS, this condition can lead to severe muscle spasms. During a reflex test, such spasms might occur and lead to a diagnosis of brisk reflexes. With MS, you may have problems with gait and overall movement, too.
- Parkinson’s disease: This condition alters brain cells in ways that can make movement difficult. It may also lead to muscle spasticity, which may cause higher reflex responses (hypertonia).
- Prior strokes or brain or spinal cord injury.
If you think you have brisk reflexes you can ask your doctor for a reflex test. This test helps determine how effective your nervous system is by assessing the reaction between your motor pathways and sensory responses.
During the test, your doctor may tap your knees, biceps, fingers, and ankles. A normal response means your neurons respond to the tap from a reflex hammer with enough contraction (about two times).
Your overall reactions are rated against the following scale:
- 5 or higher: significant hyper reflexivity; clonus is likely
- 4: hyper reflexive muscles
- 3: brisk reflexes (more hyper reflexive than normal)
- 2: normal response
- 1: little response (hypo reflexive)
- 0: no response noted
Findings of 3 or higher in all extremities may be diagnosed as brisk reflexes. A rating of 5 means that your muscles contract several times after the deep tendon reflex test. If your doctor rates your reactions 0 or 1, your muscles show little to no contraction during the test.
If your doctor suspects a neurological disorder, they will order more tests. Imaging tests, such as MRI, can help your doctor see neurological damage.
Treatment for brisk reflexes depends on the underlying cause. If you have a neurological disorder, medications can help manage the condition and lead to reflex stability.
For example, ALS is treated with medications to reduce neuron damage. MS treatments focus on reducing the inflammation in the brain and spinal cord.
If brisk reflexes are related to an injury, you’ll likely see normal muscle contractions as your body heals.
For all causes of brisk reflexes, physical or occupational therapy can help. A series of sessions can help you learn exercises and movement strategies to help modify active reflexes. You may also learn techniques to maintain independence.
An above-average reaction to a reflex test could indicate an underlying neurological condition. However, you doctor will need to conduct other tests to make a diagnosis. After the reflex test, your doctor may also test your gait.
Your doctor might periodically perform a reflex test to see if neuron function has improved or deteriorated. Neurological diseases, when left untreated, can lead to issues with movement and disability.
Brisk reflexes may indicate a developing neurological condition. You’ll likely need to follow up with your doctor, especially if you start to experience other symptoms. Your reflexes will be tested periodically to measure any changes.