Brisk reflexes refer to an above-average response during a reflex test. This test is often done during a physical exam. Here, your doctor taps your deep tendon reflexes with a reflex hammer to measure your response. Quicker responses overall 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, such as:
- Hypothyroidism. 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 everyday 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 arise without warning and lead to a diagnosis of brisk reflexes. With MS, you may have problems with gait and overall movement, too. This neuroinflammatory disease is degenerative and may lead to future disability.
- 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/spinal cord injury.
Brisk reflexes are often diagnosed during a reflex test. If you think you have brisk reflexes prior to a scheduled appointment, you can ask your doctor for a reflex test. This exam helps determine the effectiveness of your nervous system by assessing the reaction between your motor pathways and sensory responses.
During the appointment, your doctor will use a reflex hammer to test your overall responses to taps on your deep tendon reflexes. These may be done on your knees, biceps, fingers, and ankles. A “normal” response means that your neurons respond to the tap from a reflex hammer with a sufficient amount of 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 three 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 deems a rating of 0 or 1, your muscles revealed little to no contraction during the test. The most common cause of low reflex response is peripheral neuropathy. Diabetes, anemia, and vitamin deficiency are possible causes of absent reflexes. Such conditions do not cause brisk reflexes.
If your doctor suspects a neurological disorder, they will order further testing. Imaging tests, such as an 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 while also leading 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 with one of these professionals can help you learn exercises and movement strategies to help modify active reflexes. You may also learn techniques to maintain independence. Speech therapy is helpful if you also experience difficulties.
An above-average reaction to a reflex test could possibly indicate an underlying neurological condition. However, more testing would need to be conducted to make this determination. After the reflex test, your doctor may test your gait.
Your doctor might periodically perform a reflex test to see if neuron function has improved or further deteriorated. Neurological diseases, when left untreated, can lead to further problems 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’re starting to experience other symptoms. Your reflexes will be tested periodically to measure any changes within your neurons.