Pediatric ataxia is a family of conditions which have the symptom of severely uncoordinated movement. Ataxia as a symptom has many root causes. It is associated with many different disorders and occurs when that condition affects the brain’s coordination center: the cerebellum. The cerebellum is located in back of the brain, at the base of the skull, and is sometimes called the second brain. The cerebellum is the center of unconscious coordination in the body, and as such, is the part of the brain which allows us to learn to walk in a balanced and coordinated way, to run, to eat with utensils, and all manner of everyday movement. The cerebellum works in tight coordination with sensory pathways in the spinal cord. Conditions which affect these pathways can also lead to ataxia.
In children, ataxia is a very rare neurological symptom, and the diseases and conditions which cause it are myriad. Addressing the underlying condition first leads to treatment of the cause of ataxia. Recovery is dependent upon the level of damage done to the cerebellar-spinal area. In some cases, it is temporary (as in some post-infectious cases), but many children will require additional therapy to recover their coordination.
Treatment plans for all ataxias almost always call for as much exercise as possible in addition to formal physical and occupational therapy. Addressing the emotional needs of children with ataxia is often paramount, especially if they have a chronic, progressive form of the condition. If speech has been affected, speech therapy is also prescribed. Depending upon the root cause of the ataxia, additional specific treatments are available.
A physical exam is the first stage of ataxia diagnosis; a wide, staggering gait while walking is a hallmark sign of the condition. Many children with ataxia are unable to walk in a straight line, and their movements are entirely uncoordinated. Abnormal eye movements, called nystagmus, as well as the inability to judge depth, are other key signs of ataxia that can be seen in a physical exam. Many children with ataxia will also develop slurred speech or have difficulty swallowing. A definitive diagnosis is usually made with brain scans, blood work, and sometimes genetic testing.
Post-Infection, Post-Trauma, and Other Acquired Ataxias
Pediatric ataxia is most commonly a result of infection or injury to the brain, causing damage to the cerebellum or sensory pathways of the spinal cord that allow a person to sense themselves in space (proprioception). Stoke, traumatic brain injury, tumors, vitamin deficiencies (e.g. folate), poisoning (e.g. lead, alcohol, some anti-seizure medications), and infections (e.g. chicken pox, coxsackievirus, influenza, Epstein-Barr viruses) are the most common causes of acquired ataxia in children. Ataxias that are caused by infection and injury generally have a sudden, acute onset, but progression can often be arrested and in many cases ataxic symptoms may disappear with treatment of the underlying disease.
Some ataxias are the result of problems during prenatal development. Chiari malformations, Dandy-Walker syndrome, and encephalocele are three of the most common congenital ataxias. While these ataxias are present at birth and chronic, they are not progressively degenerative.
Genetic disorders may also cause ataxia. Ataxia telangiectasia and Friedreich ataxia are chronic and progressively degenerative diseases caused by two different recessive gene mutations, meaning that a child must inherit the gene from both parents for it to cause the disease.
Friedreich’s ataxia is the most common inherited cause of ataxia and affects 1 in 30,000 children. A gene mutation in Friedreich’s ataxia causes damage to mitochondria, the organelles which provide energy to cells. Friedreich’s ataxia appears late in childhood, usually between the ages of 5 to 15. While Friedreich’s ataxia is a progressively degenerative disease, it does not typically affect mental ability. While research for drug therapies are active, rigorous physical therapy protocols are being developed that slow the loss of coordination and function. There is currently no cure.
Ataxia telangiectasia is a very rare disease that may affect as few as 1 in 100,000 children. The gene mutation that causes ataxia telangiectasia results in cells' failure to repair cellular DNA, creating a cascade of symptoms over time.
Signs of ataxia telangiectasia may be noted as early as the stage when walking and standing begin to develop, and may often be misdiagnosed at that time as cerebral palsy. Children with ataxia telangiectasia have trouble standing and walking without assistance. Gross and fine motor movements, as well as the ability to control eye and vocal movement, deteriorate over time. Between ages 5 to 8 children may develop permanent “blood-shot eyes” and prominent small broken blood vessels on the face and neck--called telangiectasia. Over time, the immune system also begins to weaken. Mental abilities are sometimes negatively affected. Ataxia telangiectasia is definitively diagnosed with genetic testing to distinguish it from cerebral palsy and Friedrich's ataxia, which may be done after positive clinical exams and brain scans. Currently, no cure exists for ataxia telangiectasia. Most therapies focus on supportive care symptomatic treatment, with specific treatment for related conditions.