Brain Matters

CORTICOBASAL SYNDROME - Diagnostic Criteria

From Boeve B, Lang A, Litvan I. Corticobasal degeneration and its relationship to progressive supranuclear palsy and frontotemporal dementia. Ann Neurol 2003;54:S15

Core features

1- Insidious onset and progressive course

2- No identifiable cause (eg, tumor or infarction)

3- Cortical dysfunction as reflected by at least one of the following:
* Focal or asymmetric ideomotor apraxia
* Alien limb phenomenon
* Cortical sensory loss
* Visual or sensory hemineglect
* Constructional apraxia
* Focal or asymmetric myoclonus
* Apraxia of speech or nonfluent aphasia

4- Extrapyramidal dysfunction as reflected by at least one of the following:
* Focal or asymmetric appendicular rigidity lacking prominent and sustained levodopa response
* Focal or asymmetric appendicular dystonia

Supportive investigations
5- Variable degrees of focal or lateralized cognitive dysfunction, with relative preservation of learning and memory, on
neuropsychometric testing

6- Focal or asymmetric atrophy on CT or MRI, typically maximal in parietofrontal cortex

7- Focal or asymmetric hypoperfusion on single photon emission CT (SPECT) and hypometabolism on positron emission tomography (PET), typically maximal in parietofrontal cortex with or without basal ganglia with or without thalamus