SV-PPA

The diagnostic criteria for semantic variant PPA (SV-PPA) developed by an international group of PPA investigators use two diagnostic categories: clinical diagnosis and imaging-supported diagnosis. The criteria must be met as defined without meeting any of the exclusion criteria for primary progressive aphasia (PPA).

Primary Progressive Aphasia (PPA)

Criteria 1-3 must be answered positively for a PPA diagnosis.

1. Most prominent clinical feature is difficulty with language: e.g., word-finding deficits, paraphasias, effortful speech, grammatical and/or comprehension deficits
2. These deficits are the principal cause of impaired daily living activities: e.g., problems with communication activity related to speech and language, such as using the telephone; or performing routine job responsibilities that require verbal communication
3. Aphasia should be the most prominent deficit at symptom onset and for the initial phases of the disease.

Exclusion Criteria

Criteria 1-4 must be answered negatively for a PPA diagnosis.

1. Pattern of deficits is better accounted for by other non-degenerative nervous system or medical disorders: e.g., neoplasm, cerebrovascular disease, hypothyroidism
2. Cognitive disturbance is better accounted for by a psychiatric diagnosis: e.g., depression, bipolar disorder, schizophrenia, pre-existing personality disorder
3. Prominent initial episodic memory, visual memory and visuo-perceptual impairments: e.g., inability to copy simple line drawings
4. Prominent initial behavioral disturbance: e.g., marked disinhibition, emotional detachment, hyperorality or repetitive/compulsive behaviors

Diagnostic Criteria for Semantic Variant PPA (SV-PPA)

Also known as semantic dementia (SD) or PPA-S

Clinical Diagnosis of SV-PPA

Both of the core features (1 and 2) must be present, and at least three of the following other features (3-6) must be present.

1. Poor confrontation naming (of pictures or objects), particularly for low familiarity or low frequency items
2. Impaired single-word comprehension
3. Poor object knowledge, particularly for low frequency or low familiarity items
4. Surface dyslexia and/or dysgraphia
5. Spared repetition
6. Spared motor speech (no distortions) and grammar

Imaging-Supported SV-PPA Diagnosis

Both of the following criteria must be present.

1. Clinical diagnosis of SV-PPA
2. Imaging must show one or more of the following results:
1. Predominant anterior temporal lobe atrophy on MRI
2. Predominant anterior temporal hypoperfusion or hypometabolism on SPECT or PET