Introduction: In some types of degenerative dementia aphasia is the main disorder. In primary progressive aphasia. (PPA) atrophy is limited to the dominant peri-sylvan region. We present 18 cases of progressive aphasia of degenerative origin, with or without dementia.
Material and methods: We describe the clinical and neuro-radiological findings in 3 patients with 'aphasic dementia and motor neuron disease (ADMND)', 7 with 'semantic dementia' (DS), and 4 with 'fronto-temporal dementia' with 'marked non-fluent aphasia' (AFTD). Criteria published in recent years were used.
Results: In patients with ADMND non-fluent aphasia progressed to global aphasia, with dementia occurring after 2-9 months, and death after an average of 17 months. In cases with SD, initial anomic aphasia progressed to transcortical sensory or global aphasia, and in patients with AFTD, Broca's aphasia or motor transcortical aphasia progressed to global aphasia. Seven of these patients had been initially diagnosed as having PPA and became demented after two years or more. In most of the cases the cognitive disorder had the characteristics of fronto-temporal dementia. All cases had cortical atrophy or asymmetrical cortical or cortico-subcortical atrophy. The 4 cases of non-fluent PPA were not demented after 21 months-6 years of illness, and showed perisylvan and left fronto-temporopolar atrophy.
Conclusions: The PPA may correspond to the initial form of at least three varieties of dementia, usually the fronto-temporal type. Dementia occurs after two years or more, except in patients with motor neurone disease, when there is a latent period of less than one year.