Dysmetria can be defined as a medical condition in which the person cannot control the range of movement in using different muscle groups. It is considered that these persons are not able to judge distances accurately, their ability of controlling the range of movement being impaired by different reasons. Dysmetria is of two different types, motor and saccadic. The motor one is characterized by dysrhythmic taping of the extremities, while the saccadic one is primarily encountered at the level of the eyes (quick and simultaneous movements).
What Causes Dysmetria?
These are the main causes that lead to the appearance of dysmetria:
- Lesions at the level of the cerebellum
- Injury or trauma, causing lesions of the proprioceptive nerves leading to the cerebellum
- Multiple sclerosis
- Amyotrophic lateral sclerosis
- Midline cerebellar syndromes
- Hemispheric cerebellar syndrome
- Cerebellar motor syndrome
- Cerebellar cognitive affective syndrome
The diagnosis of dysmetria and potential underlying condition is made by the neurologist. One of the most common tests performed for the identification of dysmetria is the finger-to-nose test. The patient is required to touch his/her own nose with the finger. Depending on how well the patient appreciates the distance and the spatial position, the doctor can use the information to order further investigations and confirm the diagnosis of dysmetria. For example, the neurologist might also ask the patient to perform the heel-to-shin test or to try and draw an imaginary circle, using the legs or the arms. If these are positive, exhibiting a lack of control over the range of movement, the patient will have to undergo a MRI investigation. The MRI analysis will provide information about the underlying conditions that are causing such problems, such as the damage to the cerebellum.
Dysmetria is a symptom of another medical problem and there are no treatments to eliminate it forever. However, certain medications can be taken, in order to keep the symptoms under control.
These are the most common treatment solutions recommended for patients who suffer from dysmetria:
- Isoniazid (commonly used for the treatment of tuberculosis)
- Clonazepam (medication with multiple properties – hypnotic, sedative, amnestic, muscle relaxant, anticonvulsant and anxiolytic)
- Frenkel exercises
- Recommended for those who suffer from dysmetria and ataxia
- Slow repetitious exercises
- The difficulty of the exercises increases with the passing of time
- The patient watches the movements he/she performs, trying to correct them
- It is based on the idea that the brain will learn how to compensate for the deficits that exist at the level of cerebellum
- Chiropractic neurology
- Holistic treatment with high efficiency on dysmetria
- Trial experimental phase (UK)
- Eye movement rehearsal
- The patient is trained to imagine the movements before actually attempting to perform them
- Deep brain stimulation
- Improvement of motor skills in patients who are suffering from degenerative conditions, such as multiple sclerosis
These are the most common conditions that are associated with dysmetria:
- Multiple sclerosis – inflammatory medical condition, in which the protective lining of the nerve cells (in the brain and spinal cord) are damaged
- Amyotrophic lateral sclerosis (Lou Gehrig’s disease/ Charcot disease) – medical condition in which the neurons die (motor neuron disease, with unknown cause)
- Neoplasm – different types of cancer can damage the cerebellum, affecting the ability to control the range of movement
- Cerebrovascular stroke – depending on where the stroke actually happened, both the cerebellum and the nerves in the area might have been damaged
- Autosomal dominant spinocerebellar ataxia (spinocerebellar atrophy/spinocerebellar degeneration) – progressive and degenerative disease, in which the patient experiences dysmetria, areflexia (no neurologic reflexes) and nystagmus (rapid eye movements), among other symptoms
- Friedreich’s ataxia
- Especially in children
- Autosomal recessive inherited disease, in which the nervous system suffers from progressive damage
- The cognitive functioning remains intact, despite the other symptoms that are present
- Cerebellar malformations
- If the malformation of the cerebellum also affects the brainstem, dysmetria can occur, among other symptoms
Dysmetria vs Ataxia
Patients who are diagnosed with ataxia cannot control their voluntary movements, the most important complaints being related to the unsteady gait patterns. Ataxia occurs due to a problem at the level of the cerebellum, affecting the coordination of voluntary movements. People who suffer from ataxia often have a large support center, walking with their feet wide apart. They may have difficulties in walking with one foot in front of the other.
Those who suffer from dysmetria, on the other hand, have difficulties when it comes to judging the distance to a certain target (such as when they are required to bring their finger to the nose). The problems become obvious when a person has to reach for an object, the ability to control the regular range of movement being obviously impaired.
In conclusion, it is very important to recognize the difference between dysmetria and ataxia. Apart from that, dysmetria should always be regarded as a serious symptom, suggestive of cerebellum or nerve damage. While the neurological tests indicate that the patient might suffer from dysmetria (caused by an underlying condition), it is the MRI that provides the final answer. The identification of dysmetria as a symptom is very important, as it will guide the doctor in choosing other investigations for the underlying conditions that might be causing the dysmetria. It is important to remember that the majority of the conditions that lead to the appearance of dysmetria are not treatable; however, their symptoms – dysmetria included – can be kept under control with the right medication, physical therapy and other treatment solutions.