Hyporeflexia refers to a condition in which your muscles are less responsive to stimuli. If your muscles don’t respond at all to stimuli, this is known as areflexia. Your muscles may be so weak that you can’t do everyday activities. This is the opposite of hyperreflexia, in which there’s an excessive amount of muscular response.
While hyporeflexia might occur independently, it’s more often associated with another underlying cause. This means diagnosis, treatment, and outcome can vary significantly.
Symptoms of hyporeflexia can also occur gradually. In such cases, you might experience a slow loss of muscle response. At first, you might shake off the symptoms as simply being clumsy.
Everyday tasks may increasingly become difficult, such as:
- holding objects
- keeping a good posture
In the most severe cases, hyporeflexia can cause a complete loss of muscle use.
Hyporeflexia develops as a result of damage to motor neurons. These neurons send messages between your brain and spinal cord. Collectively, they send messages to the rest of your body to control muscle movements.
This condition may also be related to one of the following:
Amyotrophic lateral sclerosis (ALS)
More commonly known as Lou Gehrig’s disease, ALS is a progressive neurological disease that destroys brain and spinal cord cells. Over time, this can cause muscle weakness throughout the body. Other symptoms of ALS include slurred speech, memory loss, and breathing difficulties.
Guillain-Barré syndrome (GBS)
This is another type of degenerative condition that affects your nervous system. With GBS, your body attacks normally healthy tissues, which disrupts brain signals to your muscles. In addition to weak muscles, GBS may cause breathing problems and high blood pressure.
Chronic inflammatory demyelinating polyneuropathy (CIDP)
This is disorder is marked by damage to the nerve fibers in your brain. CIDP can start off with symptoms such as tingling extremities or numbness in your muscles.
Eventually, CIDP causes a significant loss of muscle reflexes. This is a long-term condition that can lead to worsening symptoms without treatment.
Also called underactive or “low” thyroid, this condition can lead to fatigue, weak muscles, and colder-than-normal body temperature. Hypothyroidism develops when your thyroid doesn’t produce enough hormones to maintain basic body functions.
Certain spinal cord injuries can cause nerve damage, which can lead to weak muscles.
Strokes may lead to hypotonia, or low muscle tone in some limbs. Hypotonia is often temporary in most people who experience a stroke, but in some it’s permanent.
Medication side effects
People who take muscles relaxers may experience hyporeflexia as a temporary side effect.
Because hyporeflexia may be related to numerous different conditions, it can be difficult to diagnose at first. You’ll need to see your doctor for a physical. At this point, they’ll also ask you when you started losing muscle response, and how long it’s been happening. You’ll also need to tell your doctor about any other symptoms you’re experiencing.
At your appointment, your doctor will likely use a reflex hammer to see how your muscles respond.
To make an accurate diagnosis, your doctor may also order a combination of the following tests:
- a biopsy of your muscles or nerves
- blood work
- electromyography (EMG)
- MRI scan
- nerve conduction velocity (NCV) test
- spinal tap
- urine tests
Because there are so many possible underlying causes for hyporeflexia, there isn’t one single test that can help your doctor diagnose it.
With low muscle response, you’re at risk for serious accidents. Falls from weak leg muscles, for example, can lead to head injuries and bone fractures. Not being able to drive can lead to vehicular accidents.
Both ALS and GBS can lead to paralysis. With ALS, paralysis may gradually occur. A severe GBS attack can cause temporary paralysis.
Sometimes, in cases of spinal trauma, hyporeflexia can turn into hyperreflexia.
Treatment for hyporeflexia aims at improving muscle reaction. From a medical standpoint, there are two methods that might help: medications and physical therapy.
The types of medications your doctor will recommend may depend on the underlying cause of hyporeflexia. For example, if you have GBS or CIDP, your doctor may prescribe steroids. This helps to reduce the inflammation caused by the body attacking its own healthy tissues.
Hypothyroidism is treated with thyroid replacement hormones to improve your overall symptoms.
A physical therapist can guide you through muscle training and strengthening routines. Additionally, your doctor may recommend occupational therapy. This helps you learn how to move around independently and can keep you safe. Physiotherapy may aid in muscle strength too.
You can also talk to your doctor about how to exercise safely to improve gross motor skills (such as walking and running) and overall muscle strength. If you do exercise, make sure you have a workout buddy as a safety precaution.
Your overall prognosis depends on the underlying causes of your condition. When diagnosed early, the outlook for hyporeflexia is hopeful with treatments and therapies. In the case of related neurological diseases, your doctor will work with you to help decrease disease progression. This can possibly help slow down potentially disabling symptoms.
If you notice any differences in muscle reaction, make an appointment with your doctor. The earlier these types of conditions are detected, the better the long-term outlook.