Primary progressive aphasia

Primary progressive aphasia was first described in 1982 and is the umbrella term for the language-variant frontotemporal dementias associated with frontotemporal lobar degeneration (FTLD) ³.

Clinical presentation

It is an insidious disorder characterised by gradual impairment of speech and language that predates, usually by many years, the onset of more global cognitive deficits.

Pathology

Primary progressive aphasia syndromes were originally classified as either fluent (semantic dementia) or non-fluent (progressive non-fluent aphasia). However, a third clinical entity (logopaenic dementia) has since been characterised, which actually represents an uncommon clinical variant of Alzheimer's disease ^1,2,4.

It is, therefore, important to note that this group is not only clinically heterogeneous but also is the result of a number of pathological processes, including in a minority of cases Alzheimer's disease ^1,4.  

Subtypes

The clinical subtypes of primary progressive aphasia include ²:

• agrammatic variant primary progressive aphasia (also known as progressive nonfluent aphasia)
• semantic variant primary progressive aphasia(also known as semantic dementia)
• logopaenic variant primary progressive aphasia

Inclusion criteria ²:

• most prominent clinical feature is difficulty with language
• these deficits are the principal cause of impaired daily living activities
• aphasia should be the most prominent deficit at symptom onset and for the initial phases of the disease

Exclusion criteria ²:

• pattern of deficit is better accounted for by other nondegenerative nervous system or other disorders
• cogntive disturbance is better accounted for by a  psychiatric diagnosis
• prominent initial episodic memory, visual memory, and visuoperceptual impairments
• prominent, initial behavioural disturbance