Clinical and imaging findings in language-predominant dementia syndromes: a case series

Background: Primary progressive aphasia (PPA) is a rare neurodegenerative disorder, with estimated prevalence of 3-4 per 100.000 population, characterized by predominant language impairment, alongside prejudice to daily activities and without equivalent disturbance on behavior and episodic memory during symptoms emerge. While PPA is the prototype of a language-predominant dementia syndrome, aphasia could be the presenting symptom of other conditions such as Corticobasal Syndrome, defined as a combination of cortical and subcortical signs usually affecting the parietal lobes asymmetrically. Objective: Describe five PPA cases of patients followed at a cognitive neurology reference center in Recife. Methods: Case series with thorough revision of health-records, imaging and laboratory tests of all patients classified with language-predominant dementia syndromes between 2019-2023 in a tertiary center. Results: Five female patients were described, with ages from 56 to 65 years (average 60.5 years). Language impairment was the first isolated manifestation observed in 80% of cases. Associated symptoms were difficulty in lexical access during speech (n=3), paraphasia (n=3), echolalia (n=2), writing deficits (n=2), apraxia of speech (n=1), dysexecutive (n=1) and stuttering (n=1). Two patients (40%) referred preference for low nutritional foods and one patient (20%) evolved with mutism. Atypical parkinsonism is present in 40% of the cases, raising the possibility of PPA secondary to corticobasal syndrome. Magnetic resonance imaging (MRI) revealed a more pronounced volumetric reduction in the parietal (60% of cases) and frontotemporal (40% of cases) lobes, with a predominance on the left. Metabolic positron-emission tomography (FDG-PET) showed glycolytic hypometabolism compatible with metabolic pattern of frontotemporal dementia (n=3), corticobasal degeneration (n=1), and Alzheimer’s disease (n=1). The hypothesized variants were semantic (n=3), nonfluent (n=1), and logopenic (n=1). Multidisciplinary intervention with speech therapy had great adherence in 80% of cases, and selective serotonin reuptake inhibitors (SSRIs) were prescribed for symptoms in 80% of cases. Conclusion: PPA is a diagnosis to be considered in middle adulthood and elderly patients with language impairment. The differential diagnosis among other cognitive disorders is subtle and may request imaging. Owing to PPA’s insidious nature, the outcome is progressive cognitive decline with language predominance in all cases, associated with movement disorders in 40% and with mutual predominance of behavior disorders in another 40% of cases. These patients’ identification allows the early institution of a multidisciplinary therapeutic plan, which aims to retard the progression of dementia and to improve patients’ and caregivers’ quality of life.