Mandatory criteria | Insidious onset |
No sustained response to levodopa treatment* | |
Major and minor criteria* | |
Motor | Akinetic rigid syndrome |
Focal or segmental myoclonus | |
Asymmetric dystonia | |
Cortical motor sensory features | Limb apraxia |
Alien limb syndrome | |
Cortical sensory loss or dyscalculia | |
Cognitive features | Speech and language impairment |
Frontal executive dysfunction | |
Visuospatial deficits |
A diagnosis of corticobasal syndrome requires all mandatory criteria, two major criteria (in italics) and two minor criteria.
There are other proposed criteria, but the authors favour this as equal emphasis is attributed to the cognitive and motor aspects, furthermore the modified Cambridge criteria may pick up patients earlier in their disease course when compared with the Mayo and Toronto criteria.12
*The response of the parkinsonism to levodopa therapy should be tested with at least 25/250 mg of carbidopa/levodopa administered three times a day for at least 2 months. The response to levodopa is considered poor when the extrapyramidal features fail to show marked improvement, or the therapeutic effect is transient.