Published: 18 Jun 2025

ICD9: 781.3      ICD10: R27.8      ICD11: MB45.Y

"Dysmetria, Ataxia" is a combination of two neurological signs often seen together, indicating a problem with the cerebellum or its connections.
Let's break down each term:

Dysmetria: This refers to the inability to judge distance or scale. People with dysmetria will overshoot (hypermetria) or undershoot (hypometria) when trying to reach for an object or perform a movement. It's like their internal measuring system is off. Examples:
Reaching for a doorknob and going past it.
Tapping their nose repeatedly but missing the target or hitting too hard.
When walking, taking steps that are too large or too small.

Ataxia: This is a broader term meaning lack of coordination. It affects balance, gait (walking), speech, and limb movements. People with ataxia may appear clumsy, unsteady, and have difficulty with smooth, coordinated movements. Types of ataxia are named based on the area of the brain most responsible for the presentation of ataxia.
Cerebellar Ataxia: Impaired coordination of movement, balance, and gait. The most common type when you see "Dysmetria, Ataxia" together, as the cerebellum is crucial for both coordination and judging distance.
Sensory Ataxia: Loss of position sense (proprioception). Patients may have difficulty coordinating movements because they are unable to sense the position of their limbs.
Vestibular Ataxia: Inner ear dysfunction causes problems with balance and spatial orientation.

Why they often occur together:

The cerebellum is the brain region most responsible for coordination and precision in movement. It receives sensory information about body position and uses this information to fine-tune movements. Since dysmetria is essentially a problem with the precision of movement, and ataxia is a general lack of coordination, damage to the cerebellum or its pathways often results in both conditions occurring together.

Possible Causes (Examples):

Many things can cause "Dysmetria, Ataxia." Here are some possibilities:

Stroke: Affecting the cerebellum or its connections.
Tumor: Cerebellar tumors can directly damage cerebellar tissue or compress it.
Multiple Sclerosis (MS): Demyelination in the brain and spinal cord can disrupt the cerebellar circuits.
Cerebral Palsy: A group of disorders that affect movement and coordination, often due to brain damage during development.
Genetic Conditions: Such as spinocerebellar ataxias (SCAs), Friedreich's ataxia.
Head Trauma: Can directly damage the cerebellum.
Alcohol Abuse: Chronic alcohol use can damage the cerebellum.
Certain Medications: Some drugs can have ataxia as a side effect.
Vitamin Deficiencies: Notably vitamin E or B12 deficiency.
Infections: Certain infections can affect the cerebellum.

Diagnosis:

A doctor will perform a neurological exam to assess:

Coordination: Finger-to-nose test, heel-to-shin test, rapid alternating movements.
Balance and Gait: Observing how the person walks and stands.
Speech: Slurred or scanning speech (ataxic dysarthria).
Reflexes:
Sensory Function:

They may order:

MRI or CT scan of the brain: To look for structural abnormalities, stroke, or tumors.
Genetic testing: If a hereditary ataxia is suspected.
Blood tests: To check for vitamin deficiencies, infections, or other underlying causes.
Lumbar puncture (spinal tap): To analyze cerebrospinal fluid in some cases.

Treatment:

Treatment depends entirely on the underlying cause.

Addressing the underlying cause: If it's a treatable condition like a vitamin deficiency or medication side effect, addressing that will be the primary focus.
Physical therapy: To improve strength, balance, and coordination.
Occupational therapy: To help with daily living activities.
Speech therapy: To address speech problems.
Assistive devices: Walkers, canes, or wheelchairs may be needed for mobility.
Medications: There are some medications that can help manage specific types of ataxia, but these are not a cure. For example, some medications can help with tremor or muscle stiffness.

Important Note: "Dysmetria, Ataxia" are signs of a neurological problem, not a diagnosis in themselves. It is essential to identify the underlying cause to determine the appropriate treatment and prognosis. If you suspect you or someone you know has these symptoms, seeking medical attention is crucial.