Differential Diagnosis for Abrupt Onset Ataxia in a 60-Year-Old Woman with Negative Brain MRI
Single Most Likely Diagnosis
- Vestibular Neuritis or Labyrinthitis: This condition is characterized by inflammation of the vestibular nerve or labyrinth, leading to sudden onset of vertigo, nausea, vomiting, and ataxia. A negative brain MRI supports this diagnosis, as it rules out central causes of ataxia.
Other Likely Diagnoses
- Peripheral Vestibular Disorder: Disorders affecting the peripheral vestibular system, such as benign paroxysmal positional vertigo (BPPV), can cause abrupt onset ataxia.
- Medication-Induced Ataxia: Certain medications, including sedatives, anticonvulsants, and antibiotics, can cause ataxia as a side effect.
- Alcohol-Related Ataxia: Acute alcohol intoxication or withdrawal can lead to ataxia.
Do Not Miss Diagnoses
- Posterior Circulation Stroke: Although the brain MRI is negative, it is essential to consider the possibility of a stroke, particularly in the posterior circulation, which may not always be visible on initial imaging. Repeat imaging or further evaluation with CT angiography or MR angiography may be necessary.
- Multiple Sclerosis: A relapse of multiple sclerosis can present with ataxia, and a negative brain MRI does not entirely rule out this diagnosis, as lesions may be present in the spinal cord or not visible on MRI.
- Wernicke's Encephalopathy: This is a medical emergency caused by thiamine deficiency, which can present with ataxia, ophthalmoplegia, and confusion.
Rare Diagnoses
- Creutzfeldt-Jakob Disease: A rare, degenerative, and fatal brain disorder that can cause ataxia, among other symptoms.
- Paraneoplastic Cerebellar Degeneration: A rare condition associated with certain cancers, which can cause subacute or acute ataxia.
- Miller Fisher Syndrome: A rare variant of Guillain-Barré syndrome, characterized by ataxia, areflexia, and ophthalmoplegia.