Corticobasal Syndrome and Corticobasal Degeneration Differential Diagnoses

Updated: Dec 04, 2019
  • Author: Alexander Pantelyat, MD; Chief Editor: Selim R Benbadis, MD  more...
  • Print

Diagnostic Considerations

The key limiting factors for the diagnostic considerations include the lack of a reliable patient-level in vivobiomarker for corticobasal degeneration (CBD) and the significant heterogeneity of clinical CBD presentations (detailed in the Overview and Presentation sections). A careful historical review (including family history) aiming to determine the tempo of symptom progression is crucial (for example, patients with corticobasal syndrome (CBS) often look and sound like they have had a stroke, but there is no history of acute stroke and no imaging evidence of same), followed by a thorough examination targeting the wide range of motor and non-motor findings present in the phenotypes associated with CBD. Features that suggest a synucleinopathy (Parkinson disease, dementia with Lewy bodies, or multiple system atrophy) rather than a tauopathy like CBD include rapid eye movement sleep behavior disorder (confirmed with polysomnography) and loss of smell (which can be formally evaluated using tests such as the University of Pennsylvania Smell Identification Test). Rapid progression of symptoms in the course of < 2 years should trigger additional workup for rapidly progressive dementia, as patients with Creutzfeldt-Jakob disease can present with CBS. It is important to keep in mind that CBS can represent an atypical presentation of Alzheimer disease (AD), and that AD pathology is responsible for 20–30% of CBS cases.

Differential Diagnoses