Ataxia has numerous causes – with multiple classification systems being present. However, cause-wise, ataxia can be classified into (1,2):

Hereditary Ataxias
These include different forms of ataxia that are inherited vertically along generations. They occur due to genetic mutations/aberrations transmitted from parents to children. Inherited ataxias are usually characterized by prolonged and slower disease progression compared to sporadic forms of ataxia. There are different modes of inheritance for ataxia; including:

• Autosomal dominant: Having one affected parent puts the child at risk of developing ataxia. One of the most widely known autosomal dominant ataxias includes Spinocerebellar Ataxia
• Autosomal recessive: This mode requires both parents to be disease carriers, or one carrier and one diseased, in order to transmit the disease to the offspring. Some of the widely autosomal recessive forms of ataxia include Friedreich’s Ataxia and Ataxia Telangectasia.
• Mitochondrial inheritance: This mode precludes a 100% risk of disease presentation if the mother is affected, and 0% if the father is the affected person. It occurs due to point mutations within the mother’s mitochondrial DNA which is exclusively transmitted to her offspring. Some ataxias in this category include Myoclonic Epilepsy with Ragged Red Fibers (MERRF) and Mitochondrial Encephalomyopathy.

Sporadic Ataxias
These include different ataxia presentations in the absence of family history. This form is usually diagnosed preliminarily until a hereditary cause is found. It is usually due to affection of one of the three systems concerned with balance and coordination – namely the cerebellum, the vestibular system (within the inner ear), and the proprioceptive sensory pathway. According to whether or not we know the exact cause of this cause of ataxia, we can divide sporadic ataxias into either:

• Idiopathic ataxia (Also known as idiopathic late-onset cerebellar ataxia (ILOCA)): This form occurs due to reasons that are still unknown to us. It usually occurs in older ages ranging from 50s to 70s.
• Acquired ataxia: Acquired forms of ataxia usually occur due to diseases affecting the cerebellum – the main brain areas concerned with balance and proper coordination mentioned before. Some causes include:
• Strokes involving the cerebellum or brain stem
• Multiple Sclerosis
• Cerebellar tumors
• Cerebellar Infections
• Creutzfeldt–Jakob disease
• Vitamin deficiencies such as vitamin B1 and B12
• Hypothyroidism
• Excessive alcohol intake