Ataxia is a lack of muscle coordination which may affect speech, eye movements, the ability to swallow, walking, picking up objects, and other voluntary movements.
Many different things can cause ataxia, including multiple sclerosis, head trauma, alcohol abuse, stroke, cerebral palsy, genetics, or tumor. Ataxia may also be a symptom associated with certain infections.
There are many types of ataxia. In this article, we will discuss some of the more common types, causes, and available treatments.
Fast facts on ataxia
Here are some key points about ataxia. More detail and supporting information is in the main article.
Ataxia can be caused by a wide range of factors.
Symptoms can include poor coordination, slurred speech, tremors, and hearing problems.
Diagnosis of ataxia can be challenging and often involves a range of tests.
Although ataxia is not always curable, symptoms can often be alleviated.
What is ataxia?
Ataxia refers to a group of disorders that can affect coordination, speech, and balance. It can also make it hard to swallow and walk.
Some people are born with ataxia, but others develop it slowly, over time. For some, it can result from another condition, such as a stoke, multiple sclerosis, or a brain tumor, or a head injury or excessive alcohol consumption.
Ataxia can get worse over time, or it can stabilize. This depends partly on the cause.
The following are some of the more common types of ataxia:
The cerebellum helps combine sensory perception, coordination, and motor control
This is ataxia caused by a dysfunction of the cerebellum – a region of the brain involved in the assimilation of sensory perception, coordination, and motor control.
Cerebellar ataxia can cause neurological problems such as:
lack of coordination between organs, muscles, limbs, or joints
impaired ability to control distance, power, and speed of an arm, hand, leg, or eye movement
difficulty accurately estimating how much time has passed
inability to perform rapid, alternating movements
The extent of symptoms depends on which parts of the cerebellum are damaged, and whether lesions occur on one side (unilateral) or both sides (bilateral).
If the vestibulocerebellum is affected, the person’s balance and eye movement control will be affected. The person will typically stand with feet wide apart in order to gain better balance and avoid swaying backward and forward.
Even when the patient’s eyes are open, balance may be difficult with feet together. If the spinocerebellum is affected, the patient will have an unusual gait with unequal steps, sideways steps, and stuttering starts and stops. The spinocerebellum regulates body and limb movements.
If the cerebrocerebellum is affected, the person will have problems with voluntary, planned movements. The head, eyes, limbs, and torso may tremble as voluntary moves are carried out. Speech may be slurred, with variations in rhythm and loudness.
This is ataxia due to loss of proprioception. Proprioception is the sense of the relative position of neighboring parts of the body. It is a sense that indicates whether the body is moving with the required effort and gives feedback on the position of body parts relative to each other.
A patient with sensory ataxia typically has an unsteady stomping gait, with the heel striking hard as it touches the ground with each step. Postural instability becomes worse in poorly lit environments. If a doctor asks the patient to stand with eyes closed and feet together, their instability will worsen. This is because loss of proprioception makes the patient much more reliant on visual data.
The patient may find it hard to perform smoothly coordinated voluntary movements with the limbs, trunk, pharynx, larynx, and eyes.
The vestibular system is affected. In acute (sudden) unilateral cases, the patient may experience vertigo, nausea, and vomiting. In slow-onset chronic bilateral cases, the patient may only experience unsteadiness.
Symptoms may vary depending on the severity and type of ataxia. If the ataxia is caused by an injury or another health condition, symptoms may emerge at any age, and may well improve and eventually disappear.
Initial ataxia symptoms usually include:
Poor limb coordination.
Dysarthria – slurred and slow speech that is difficult to produce. The patient may also have difficulties controlling volume, rhythm, and pitch.
If the ataxia progresses, other symptoms may also appear:
difficulty swallowing, leading to choking or coughing
facial expressions become less apparent
tremors, shaking or trembling in parts of the body
nystagmus, an involuntary, rapid, rhythmic, repetitive eye movement that may be vertical, horizontal, or circular
cold feet, because of a lack of muscle activity
problems with balance
walking difficulties, so that some people may need a wheelchair
vision and hearing problems
depression, due to difficulty living with the symptoms