Introduction:
Ataxia in children is a common clinical sign of various disorders consisting of discoordination of movement with an absence of muscle control during voluntary activity. Ataxia is generally caused by disorder in function of the complex circuitry connecting the basal ganglia, cerebellum, and cerebral cortex, and this is known as “cerebellar ataxia.” A wide variety of disorders can lead to acquired and inherited ataxia. Prompt identification of etiologies in progressive ataxic disorders is important, because corrective treatments may halt the degenerative process and preserve cerebellar functioning. (1) Some causes of ataxia in children and adolescents which are treatable include coenzyme Q10 (CoQ10) deficiency, ataxia with vitamin E deficiency (AVED), Niemann-Pick Type C (NPC) disease, Friedrich’s ataxia, and Cerebrotendinous xanthomatosis (CTX). (2)
Primary coenzyme Q10 (CoQ10) deficiency is a group of cerebellar ataxias with mitochondrial respiration disorders caused by autosomal recessive multi genetic mutations. The features of primary CoQ10 deficiency include early-onset exercise intolerance, progressive cerebellar ataxia, intellectual disability, seizure, stroke-like episodes, mitochondrial myopathy, hypogonadism, and steroid-resistant nephrotic syndrome, with the age at onset ranging from infancy to late adulthood. (3) CoQ10 measurement in skeletal muscle and replacement with CoQ10 30 mg /kg/day orally can be helpful. (2)
Ataxia with vitamin E deficiency (AVED) is a rare, autosomal recessive neurodegenerative disorder, with mutations in the gene encoding the a-tocopherol transfer protein (TTPA/aTTP) result in defective transportation out of the liver and systemic vitamin E deficiency. (4)  Diagnostic test includes vitamin E levels and treatment is by vitamin E (800 mg/d) in divided doses. (2)
Niemann-Pick Type C (NPC) disease is a rare genetic neurodegenerative disease with clinical spectrum ranges from a prenatal disorder to an adult-onset. The scarcity of the disease and the lack of expertise may result in misdiagnosis, delayed diagnosis, and inadequate care. This causes more physical, psychological, and intellectual deficits, inappropriate treatment, and patient disempowerment. The diagnosis of NPC is accompanied by improved quality of life if a diagnosis is made promptly and appropriate comprehensive management is instituted. (5) Serum oxysterol and NPC gene testing are considered as diagnostic tests and treatment by Miglustat 600mg/day may be useful. (2)
Friedrich’s ataxia is characterized typically by progressive gait and limb ataxia, loss of deep tendon reflexes, and dysarthria, hypertrophic cardiomyopathy, diabetes, scoliosis, distal wasting, optic atrophy, and sensorineural deafness. (6)
Cerebrotendinous xanthomatosis (CTX) is an autosomal recessively inherited lipid storage disorder due to mutations of the CYP27A1 gene result in defective enzyme activity of sterol 27-hydroxylase which catalyzes the first step in the process of cholesterol side-chain oxidation. It causes impaired primary bile acid synthesis, increased concentration of bile alcohols, and increased formation of plasma and tissue cholestanol. The symptoms of CTX are produced in part by the accumulation of cholestanol and cholesterol in almost every tissue of the body, particularly in the nervous system, atherosclerotic plaques, and tendon xanthomata. Characteristic features of CTX include intellectual disability, dementia, pyramidal and/or cerebellar signs, peripheral neuropathy, and psychiatric disturbances. Xanthomas often appear in the second or third decade. As the progressive neurological findings present in early adulthood, initial symptoms consist of prolonged neonatal jaundice, chronic infantile diarrhea, and juvenile cataract. Brain imaging of patients reveals both supra and infratentorial atrophy and parenchymal lesions in periventricular white matter, globus pallidus and internal capsule, dentate nuclei, and cerebellar white matter. (7)
Here, we provide the clinical presentation, genetic findings, treatment, and outcome of 25 patients with treatable ataxia during the last 4 years.