Table 1.

Phenotypes of tauopathies and their salient features

Phenotype		Salient features
Cognitive/behavioral disorders
bvFTD	Behavioral variant of frontotemporal dementia	Disinhibition, apathy, loss of empathy, stereotyped behaviors, hyperorality
bvAD	Behavioral or dysexecutive variant AD	Milder behavior dysfunction compared with bvFTD and earlier memory loss
PSP-F	PSP with frontal presentation	Similar to bvFTD in initial stages
Cognitive and movement overlap
PSP-RS	Richardson's syndrome	Postural instability, vertical supranuclear ophthalmoplegia, mild dementia
CBS	Corticobasal syndrome	Asymmetrical limb apraxia, parkinsonism, cortical function deficits
PSP-CBS	PSP-corticobasal syndrome	Similar to CBS
Movement disorders
PSP-P	PSP with parkinsonism	Asymmetric onset of tremor, bradykinesia, rigidity
PSP-PGF	Progressive gait freezing	Start difficulty, freezing of gait
PSP-C	PSP with predominant cerebellar ataxia	Cerebellar ataxia
PLS	Primary lateral sclerosis	Upper motor neuron signs
Language disorders
nfvPPA	Non-fluent/agrammatic variant of primary progressive aphasia	Laboured speech, sound errors, impaired grammar, Intact comprehension
svPPA	Semantic variant of primary progressive aphasia	Anomia, impaired comprehension, Intact grammar and comprehension
lvPPA	Logopenic variant of primary progressive aphasia	Anomia, fluency deficit, phonemic paraphasia and memory loss
PPAOS	Primary progressive apraxia of speech	Motor speech disorder
PSP-SL	PSP with predominant speech/language disorder	Similar to nfvPPA in initial stages
Amnestic symptoms
aAD	Amnestic Alzheimer's disease	Prominent episodic memory loss and deficits in speaking, visuospatial disorientation, and impaired executive abilities