Quick Start: Primary Progressive Aphasia and Apraxia of Speech
Definition and etiology
Primary progressive aphasia (PPA) is a clinical syndrome characterized by progressive language dysfunction. There are three variants:
Logopenic variant is most often associated with Alzheimer’s disease pathology.
Semantic variant (also called semantic dementia or temporal variant frontotemporal dementia) is most often associated with TDP-43 pathology.
Nonfluent/agrammatic variant (also called progressive nonfluent aphasia) is most often associated with tau pathology.
Primary progressive apraxia of speech (PPAOS) is an impairment in the production of speech sounds in the absence of language impairment (also called progressive apraxia of speech [PAOS]). It is most often associated with tau pathology.
Prevalence and genetic risk
Impairments of speech and language are common in neurodegenerative diseases.
The number of patients who meet criteria for primary progressive aphasia or primary progressive apraxia of speech is relatively small.
Genetic risk will depend upon underlying etiology; most individuals with primary progressive aphasia or apraxia of speech have no family history.
Cognitive and behavioral symptoms
In the logopenic variant of primary progressive aphasia there is hesitant speech, difficulty naming and finding words, and phonologic and/or repetition errors, with no loss of comprehension and preserved grammar.
In the semantic variant of primary progressive aphasia there is a loss of memory for words, starting with anomia, continuing with impaired comprehension of single words, and ultimately leading to impaired comprehension of objects as well. Speech is fluent with normal rate and minimal syntactic errors.
In the nonfluent/agrammatic variant of primary progressive aphasia there is a reduction in the ability to produce speech characterized by slow, effortful, apraxic speech; grammatical errors; short sentences; reduced phrase length; omission of articles (a, an, the); and difficulty pronouncing words, somewhat similar to that of a patient with Broca’s aphasia.
Characteristics of primary progressive apraxia of speech include slow rate, articulatory distortions, distorted sound substitutions, and segmentation of syllables.
Diagnostic criteria
Primary progressive aphasia core criteria
Inclusion: (1) Most prominent clinical feature is difficulty with language; (2) these deficits are the principal cause of impaired function; (3) aphasia is the most prominent deficit at onset and for the initial phases of the disease. (For exclusion criteria see Box 9.1 .)
Box 9.1
Primary Progressive Aphasia Core Criteria
Modified from Gorno-Tempini, M. L., Hillis, A. E., Weintraub, S., et al. (2011). Classification of primary progressive aphasia and its variants. Neurology, 76, 1006–1014.
Inclusion: Criteria 1–3 must be answered positively.
1.
Most prominent clinical feature is difficulty with language
2.
These deficits are the principal cause of impaired daily living activities
3.
Aphasia should be the most prominent deficit at symptom onset and for the initial phases of the disease
Exclusion: Criteria 1–4 must be answered negatively.
1.
Pattern of deficits is better accounted for by other nondegenerative nervous system or medical disorders
2.
Cognitive disturbance is better accounted for by a psychiatric diagnosis
3.
Prominent initial episodic memory and visuoperceptual impairments are present
4.
Prominent, initial behavioral disturbance is present
For specific criteria for the logopenic, semantic, and nonfluent/agrammatic variants, see Boxes 9.2–9.4 .
Modified from Gorno-Tempini, M. L., Hillis, A. E., Weintraub, S., et al. (2011). Classification of primary progressive aphasia and its variants. Neurology, 76, 1006–1014 as suggested by .
A
Clinical Diagnosis of Logopenic Variant Primary Progressive Aphasia
Both of the following core features must be present:
1.
Impaired single-word retrieval in spontaneous speech and naming
2.
Absence of definite grammar and comprehension impairment
At least three of the following other features must be present:
1.
Speech (phonologic) errors in spontaneous speech and naming
2.
Impaired repetition of sentences and phrases
3.
Spared single-word comprehension and object knowledge
4.
Spared motor speech
B
Imaging-Supported Logopenic Variant Diagnosis
In addition to fulfilling clinical criteria, imaging must show one of the following results:
1.
Predominant left posterior perisylvian or parietal atrophy
2.
Predominant left posterior perisylvian or parietal hypoperfusion or hypometabolism on SPECT or PET
Modified from Gorno-Tempini, M. L., Hillis, A. E., Weintraub, S., et al. (2011). Classification of primary progressive aphasia and its variants. Neurology, 76, 1006–1014.
A
Clinical Diagnosis of Semantic Variant Primary Progressive Aphasia
Both of the following core features must be present:
1.
Impaired confrontation naming
2.
Impaired single-word comprehension
A least three of the following other diagnostic features must be present:
1.
Impaired object knowledge, particularly for low-frequency or low-familiarity items
2.
Surface dyslexia or dysgraphia
3.
Spared repetition
4.
Spared speech production (grammar and motor speech)
Modified from Gorno-Tempini, M. L., Hillis, A. E., Weintraub, S., et al. (2011). Classification of primary progressive aphasia and its variants. Neurology, 76, 1006–1014.
A
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