Viral cerebellitis: This is often the most common cause of acute ataxia, especially in children. It is usually caused by a viral infection that leads to inflammation of the cerebellum, resulting in symptoms such as ataxia, dysarthria, and nystagmus.

Stroke or cerebellar infarction: Although less common than viral causes, a stroke affecting the cerebellum or its connections can lead to acute ataxia. The presentation may include sudden onset of ataxia, dysarthria, and possibly other neurological deficits.
Toxic or metabolic causes: Certain toxins (e.g., alcohol, certain medications) and metabolic disorders (e.g., hypothyroidism, vitamin B12 deficiency) can cause acute ataxia. The history and laboratory findings are crucial for diagnosing these conditions.
Post-infectious cerebellitis: This condition occurs after a viral infection and is thought to be an autoimmune response. It presents similarly to viral cerebellitis but may have a slightly different time course and response to treatment.

Brain tumor: Although rare, a brain tumor (especially in the cerebellum or brainstem) can cause acute ataxia. It is crucial to consider this diagnosis to ensure timely intervention.
Wernicke's encephalopathy: Caused by thiamine deficiency, often seen in alcoholics, this condition can present with acute ataxia, ophthalmoplegia, and confusion. It is treatable but can have severe consequences if missed.
Multiple sclerosis: An acute demyelinating lesion in the cerebellum or its connections can cause ataxia. This diagnosis is important for long-term management and treatment.

Ataxia telangiectasia: A rare genetic disorder that affects the nervous system, immune system, and other bodily systems. It typically presents in early childhood with progressive ataxia.
Miller Fisher syndrome: A rare variant of Guillain-Barré syndrome characterized by ataxia, areflexia, and ophthalmoplegia. It is an autoimmune condition that usually follows a viral infection.
Creutzfeldt-Jakob disease: A rare, degenerative, fatal brain disorder that can cause ataxia among other neurological symptoms. It is crucial to consider this diagnosis in the appropriate clinical context due to its implications for public health and the lack of effective treatment.