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Progressive apraxia of speech (PAOS) |
| Apraxia of speech is the only or dominant speech or language disturbance at the time of testing. This category is a combination of what we have previously described as primary progressive apraxia of speech and dominant apraxia of speech (Josephs et al., 2013, 2012). If aphasia is present, it must be less severe than the apraxia of speech. In aphasic patients, verbal and/or written output are agrammatic or telegraphic. Difficulties with verbal comprehension, reading comprehension, writing and naming also may be present. In patients with anomia the target words should be recognized when provided on the majority of items. Cases in which apraxia of speech and aphasia are judged to be equally severe are categorized as progressive agrammatic aphasia (see below). Dysarthria may be present. |
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Progressive agrammatic aphasia (PAA) |
| Aphasia is present, and core criteria for PPA are met (Gorno-Tempini et al., 2011). Verbal and/or written output are agrammatic or telegraphic. Difficulties with verbal comprehension, reading comprehension, writing and naming may be present. In patients with anomia the target words should be recognized when provided on the majority of items. Apraxia of speech may be present, but should be equal or less severe than the aphasia. Dysarthria may be present. |
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Logopenic progressive aphasia (LPA) |
| Aphasia is present and core criteria for PPA are met (Gorno-Tempini et al., 2011). Verbal output characteristics are not agrammatic or telegraphic. Speech may be hesitant and slow, but in contrast to the motor deficits seen in apraxia of speech or dysarthria, this results from pauses for apparent word retrieval or verbal formulation efforts. There is poor retention of spoken stimuli, resulting in poor repetition that typically increases with stimulus length and complexity. Phonemic paraphasic errors are often present, but care should be taken to differentiate them from the distortions heard in apraxia of speech. Performance on tasks involving single word comprehension should be better than on those that involve complex sentence comprehension. Anomia is usually present, but target words should be recognized on the majority of items; there are no reports from subjects or informants that the subject doesn't understand the meaning of common words. |
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Semantic dementia (SD) |
| Aphasia is present and core criteria for PPA are met (Gorno-Tempini et al., 2011). The dominant features are anomia and poor single word comprehension. Verbal output is grossly normal with regards to grammar, syntax, average phrase length and prosody, excluding pauses for word retrieval. Brief, unelaborated or simply structured sentences are infrequent. Content may be lacking in terms of substantive nouns and verbs, replacing common words with ‘thing’, for example. Anomia is most striking on confrontational naming. Loss of word meaning can be supported by failure to recognize target words when provided, or by statements from the patient or informant that he/she doesn't seem to understand or recognize the meaning of certain common words; loss of single word meaning should be disproportionate to overall aphasia severity. Performance on single word comprehension tasks should be poorer than comprehension of complex sentences containing individual words that are comprehended. Repetition, especially for non-lengthy stimuli, is relatively preserved, and phonological errors are rare. Other supporting features include disproportionately poor performance on word fluency tasks, especially category fluency, more difficulty reading irregular words than regularly spelled nonsense words, poor performance on semantic association or receptive vocabulary tasks (e.g., Pyramids and Palm Trees Test), and difficulty with facial recognition. |
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Progressive fluent aphasia (PFA) |
| Aphasia is present, and core criteria for PPA are met (Gorno-Tempini et al., 2011), with anomia being the predominant feature. Speech is fluent, but does not meet criteria for logopenic progressive aphasia or semantic dementia. As such, grammar, syntax, average phrase length and prosody are normal. There is little if any loss of word meaning and repetition of complex sentences is nearly normal. Phonemic paraphasias are absent or rare. |
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Primary progressive aphasia unclassified (PPA-U) |
| Aphasia is present, with or without apraxia of speech, and core criteria for PPA are met (Gorno-Tempini et al., 2011). The patient doesn't reliably meet criteria for any of the other categories. |
