Dysmetria is a lack of coordination that occurs when the cerebellum isn’t functioning correctly. This part of your brain allows you to make coordinated movements and process thoughts and behaviors.
Dysmetria is a symptom of many conditions and can occur with several other symptoms such as tremors and ataxia, the inability to control muscle movements.
There’s no specific treatment for dysmetria. Your doctor may recommend treatment for the underlying condition causing it or discuss how to manage the symptom as best as possible.
Dysmetria can affect upper extremities such as your arms, hands, and fingers. It can also affect your lower extremities, such as your legs and feet.
Dysmetria can appear in a few forms:
- hypermetria, which is when you overreach or overstep
- hypometria, which is when you underreach or understep
If you have dysmetria, you can’t complete movements from point to point. For example, it may be very difficult to grab an object with your fingers. You may underreach or overreach for the object you’re trying to grasp.
You can also develop ocular dysmetria, which occurs when you’re having trouble focusing your eyes.
For example, if you tried to switch your focus from one point to another, you would be unable to move your eyes in one solid motion. Instead, you may look too far away from the point or not look close enough to the point.
Saccadic dysmetria is a subset of ocular dysmetria. It affects saccades, which are rapid eye movements that occur when you switch your focus from one point to another.
In addition to dysmetria, you may have other symptoms linked to cerebellum functioning. This includes ataxia.
Dysmetria occurs when lesions develop on your cerebellum. This part of your brain can be altered by many things, including:
- cerebellar degeneration
- multiple sclerosis (MS)
- alcohol or drugs
- a reaction to barbiturates and other sedatives
- deficiencies of vitamins B1 (thiamine), B12 (cobalamin), or E
- celiac disease
- Lyme disease
- head trauma
- Hashimoto’s thyroiditis
This isn’t an exhaustive list of conditions that can cause motor problems with your cerebellum. If you have dysmetria as a symptom, you should see your doctor and have them diagnose the underlying condition.
There are several ways a doctor can test for dysmetria:
- Finger-to-nose test. This test requires you to stretch out your arm and then touch your fingers to your nose. Additionally, your doctor may ask you to touch your nose and then reach and touch the doctor’s finger in various locations. Your doctor may also ask you to do this at various speeds or with your eyes closed.
- Heel-to-shin test. This test requires you to lie down and bring your heel to the top of the opposite shin. Then you must move the heel down from your shin to the top of your foot repeatedly.
- Imaging tests. Your doctor may order a head MRI to get an image of your brain.
- Genetic tests. Your doctor may run genetic tests if there’s a possibility that something in your family health history may point to the condition responsible for your dysmetria.
Dysmetria itself can’t be cured. Your doctor may be able to control the symptom by treating the condition causing it or discuss adjustments to living with the symptom.
Your doctor may recommend occupational or physical therapy to help you manage your dysmetria. You may also need to use assistive devices in your daily life. One example is a weighted utensil that helps you eat.
You should also discuss the mental health implications of dysmetria with your doctor. They’ll help you determine if you could use professional help coping with dysmetria and learning how to adjust to any cognitive impairments that may occur alongside dysmetria. These impairments may include problems related to your mood or mental processing abilities.
Your doctor may be able to treat the dysmetria by treating the condition causing it or discuss adjustments for living with the symptom.
There’s still much to be learned about how the brain works. Research into brain functioning continues to expand, and researchers may discover more treatment options for dysmetria in the future.