Dizziness, Postural Hypotension and Postural Blackouts: Two Cases Suggesting Multiple System Atrophy

Background: Dizziness is a non-specific term used by patients to describe a variety of symptoms. The terms dizziness, vertigo, faintness, and blackouts are not synonymous but are often used interchangeably by patients. Postural blackout is a subtype of dizziness and is a result of postural hypotension, a feature of autonomic dysfunction. Case reports: We present detailed case histories of two patients treated elsewhere as postural dizziness and vertigo without a specific diagnosis. Postural blackouts were misinterpreted as postural dizziness and positional vertigo. On detailed evaluation, these were postural hypotension (PH) and postural blackouts. There were additional features of autonomic dysfunction, parkinsonism and ataxia. A diagnosis of multiple system atrophy was made as per the second consensus statement on diagnosis of multiple system atrophy. Discussion: A clinical algorithm to evaluate dizziness subtypes is discussed. Clarification of the term dizziness is necessary for a correct etiological diagnosis. A detailed history, neurological examination, bedside autonomic function testing, and follow-up is necessary in all patients presenting with dizziness. Conclusion: Postural hypotension is an important cause of postural blackouts. Multiple system atrophy should be considered in patients with postural dizziness/blackouts.