What is Dysmetria?
The inability to control the distance, speed and range of motion needed to perform coordinated movements is known as dysmetria.
Dysmetria is a neurological condition that affects a person’s ability to make movements accurately and may present with loss of balance, and poor coordination of walking, speech, and eye movements. It occurs due to damage to the part of the brain that is responsible for movements.
Causes of Dysmetria
The causes of dysmetria include: (1)
- Cerebellar Lesions: Cerebellum plays the role of coordinating movements and controlling balance. Lesions or damage to this part of the brain can lead to dysmetria.
- Stroke: Stroke can lead to damage to the brain that can further lead to dysmetria.
- Multiple sclerosis: It is a neurological disorder that affects the nervous system. It can cause dysmetria and affect coordination.
- Traumatic Brain Injury: It can lead to damage to the brain causing dysmetria.
- Vitamin Deficiencies: Deficiency of vitamin B12 and vitamin E can cause neurological problems including dysmetria.
- Infections: Infections including encephalitis and meningitis can cause inflammation of the brain leading to dysmetria.
- Alcohol or Drug Use: Chronic alcohol and drug usage can lead to dysmetria.
Dysmetria can significantly impact the quality of life. There can be difficulty in performing the activities of daily living and engaging in social activities. If left untreated it can lead to complications such as falls and injuries. It is therefore important to diagnose and treat the condition at the earliest as it can help improve the quality of life.
Anatomy and Physiology of Motor Control
Motor control refers to the ability of the body to control movements that involves a complex interplay between the nervous system, muscles, and other structures.
The primary structures involved in motor control are:
- Brain plays the role of initiating and coordinating movements. The motor cortex is located in the frontal lobe of the brain which controls voluntary movements.
- The spinal cord serves as a conduit for the neural signals between the brain and muscles. It can also initiate and control simple movements independently of the brain.
- The peripheral nervous system includes all the nerves that extend from the brain and spinal cord to the muscles and other tissues.
- The muscles are the final effectors of motor control. They force and produce movements.
The process of motor control involves the following steps:
- Motor control begins with sensory input from the environment and from the body itself. The receptors in the skin, muscles, and joints provide information about the position and movement of the body.
- The sensory information is processed in the brain and the desired movement is planned, which involves selecting appropriate muscles to activate and coordinate activity.
- The motor plan is transmitted from the brain to the muscles via the spinal cord and peripheral nerves. The muscles then contract and produce movements.
- Sensory receptors provide feedback to the brain during and after the movement, which is used to modify future plans and improve accuracy.
Symptoms of Dysmetria
Loss of ability to move is the main symptom of dysmetria. It happens because the brain is not coordinating the movement as it should.
The symptoms of dysmetria include:
- Difficulty in controlling the range of movements, leading to overshooting or undershooting. This means a person may miss a target when trying to touch something or may overreach when trying to pick up something.
- There can be an uncoordinated gait or movement. This can lead to a lack of balance, clumsiness, and difficulty with motor tasks.
- There are involuntary shaking movements due to dysmetria and may occur at rest too.
- Dysmetria can also lead to dysarthria, a condition that affects speech.
- There can be involuntary eye movements known as nystagmus.
- There are can difficulty in performing coordinated movements, especially when performing complex movements or tasks
The symptoms of dysmetria may vary depending on the underlying cause of the condition.
A series of coordination tests can be done to determine if a person has dysmetria, which includes:
- Finger-to-Nose Test: In this test, the person is asked to reach for the doctor’s finger with an outstretched arm. They are then asked to touch the nose several times. (3)
- Heel to Shin Test: The person’s heel of one foot is placed on the shin of the other leg and is made to slide down the shin towards the foot. (4)
A person with dysmetria is unable to complete these tasks easily and may also find controlling movements difficult. They may need to correct themselves again and again.
MRI scans are also done to assess the brain. This can be helpful in monitoring the disease progression. Genetic tests are also done to find if the condition is inherited.
Blood tests are performed to look for any underlying conditions including multiple sclerosis or vitamin deficiencies.
Once the condition is diagnosed, the healthcare professional works with the patient to develop a treatment plan.
Treatment of Dysmetria
The treatment of dysmetria may depend on the underlying cause and the severity of the condition. The common treatment options include:
- Physical Therapy: It helps in improving strength, coordination, and balance. Exercises are given to improve the accuracy and control the movements.
- Occupational Therapy: Strategies are taught to perform daily tasks with more accuracy and control. (2) Adaptive devices may be provided to reduce the impact of dysmetria.
- Medications: Muscle relaxants, anticonvulsants, or dopamine agonists are prescribed to treat the underlying condition that may be causing dysmetria.
- Surgery: In severe cases, surgical options including deep brain stimulation or lesioning may be considered for certain conditions that cause dysmetria such as essential tremors or dystonia.
- Lifestyle Modifications: Lifestyle modifications including getting enough rest, avoiding stress, maintaining a healthy diet, and engaging in regular exercise can be helpful in managing dysmetria. (5)
For an effective treatment, it is important to work with a healthcare professional and develop a personalized treatment plan that fits specific needs.
Coping and Management of Dysmetria
The coping and management strategies for dysmetria include:
- Using adaptive equipment including weighted utensils, special keyboards, or stabilizing devices can be helpful in improving accuracy and controlling daily activities.
- Breaking complex tasks into smaller and more manageable steps can help reduce frustration and make the tasks more achievable.
- Regular exercises can help improve strength, coordination, and balance. Activities including yoga, tai-chi, or Pilates can particularly be helpful for individuals with dysmetria.
- As stress and anxiety worsen dysmetria, relaxation techniques such as deep breathing, meditation, or visualizing techniques can help reduce stress and improve overall health.
- Seeking help and support from friends and family or support groups can help cope with dysmetria.
Prevention and Outlook for Dysmetria
Dysmetria can be prevented by engaging in regular physical activity, eating a healthy diet, getting enough rest, and avoiding alcohol.
The outlook may vary depending on the underlying cause and severity of the condition. Dysmetria cannot be cured but can be managed by a combination of medical treatments, lifestyle modifications, and supportive therapies. A person with dysmetria can lead a full and active life with proper management and care.
Dysmetria is a neurological condition that affects a person’s ability to control voluntary movements accurately. It is characterized by over or undershooting of tasks while performing tasks that require precise motor control.
It can be caused by a range of underlying conditions including Parkinson’s disease, multiple sclerosis, or cerebellar ataxia.
A thorough neurological evaluation is performed by a healthcare professional and the treatment plan depends on the cause and severity of the condition.
Dysmetria can be prevented and steps can be taken to reduce the risk of developing it. With proper management and care, people with dysmetria can live a full and active life.