A multimodal neuroimaging study of a case of crossed nonfluent/agrammatic primary progressive aphasia

Abstract

Crossed aphasia has been reported mainly as post-stroke aphasia resulting from brain damage ipsilateral to the dominant right hand. Here, we described a case of a crossed nonfluent/agrammatic primary progressive aphasia (nfvPPA), who developed a corticobasal syndrome (CBS). We collected clinical, cognitive, and neuroimaging data for four consecutive years from a 55-year-old right-handed lady (JV) presenting with speech disturbances. 18-fluorodeoxyglucose positron emission tomography (18F-FDG PET) and DaT-scan with 123I-Ioflupane were obtained. Functional MRI (fMRI) during a verb naming task was acquired to characterize patterns of language lateralization. Diffusion tensor MRI was used to evaluate white matter damage within the language network. At onset, JV presented with prominent speech output impairment and right frontal atrophy. After 3 years, language deficits worsened, with the occurrence of a mild agrammatism. The patient also developed a left-sided mild extrapyramidal bradykinetic-rigid syndrome. The clinical picture was suggestive of nfvPPA with mild left-sided extrapyramidal syndrome. At this time, voxel-wise SPM analyses of 18F-FDG PET and structural MRI showed right greater than left frontal hypometabolism and damage, which included the Broca’s area. DaT-scan showed a reduced uptake in the right striatum. FMRI during naming task demonstrated bilateral language activations, and tractography showed right superior longitudinal fasciculus (SLF) involvement. Over the following year, JV became mute and developed frank left-sided motor signs and symptoms, evolving into a CBS clinical picture. Brain atrophy worsened in frontal areas bilaterally, and extended to temporo-parietal regions, still with a right-sided asymmetry. Tractography showed an extension of damage to the left SLF and right inferior longitudinal fasciculus. We report a case of crossed nfvPPA followed longitudinally and studied with advanced neuroimaging techniques. The results highlight a complex interaction between individual premorbid developmental differences and the clinical phenotype.

Typical and atypical pathology in primary progressive aphasia variants

“…They did not show distinguishing clinical or cognitive traits relative to 4R-tau patients, although we did observe some additional right frontoinsular atrophy (possibly explained by the more liberal threshold adopted for small-group VBM analyses). One right-handed nfvPPA-PiD case presented with selective right-sided atrophy, similarly to a recent case report of “crossed” nfvPPA 36 . Of note, PiD occurred across all variants except for lvPPA.…”

“…However, one case (P50) showed a peculiar clinico-anatomical syndrome consistent with a diagnosis of crossed nfvPPA 36 , with AOS and agrammatism accompanied by clearly right more than left inferior frontal atrophy (see “Neuroimaging data”) in a strongly right-handed patient with no family history of left-handedness.…”

“…One right-handed nfvPPA-PiD case presented with selective right-sided atrophy, similarly to a recent case report of "crossed" nfvPPA. 36 Of note, PiD occurred across all variants except for lvPPA. This supports the hypothesis that PiD presents with a variable frontotemporal pattern of atrophy, leading to different clinical correlates within the spectrum of frontotemporal degeneration disorders.…”

Retraction: A Case of Crossed Logopenic Primary Progressive Aphasia in a Dextral Patient with Underlying Frontotemporal Dementia

“…Crossed aphasia in dextrals (CAD) has been reported mainly as a cerebrovascular disease (13,14), and only a few cases with PPA have been reported (24)(25)(26)(27)33). Therefore, historically, reports on CAD have mainly consisted of examinations of subjects with CAD due to cerebrovascular disease.…”

Metabolic Positron Emission Tomography Response to Gamma Knife of the Ventral Intermediate Nucleus in Essential Tremor

“…In comparison to the baseline metabolism found before treatment, after GKVIM the patients showed significantly decreased metabolism within the left thalamus (p<0.05 corrected for multiple comparisons using FWE; Figure 1; Table 2). Significant metabolic decreases were also identified remotely in the right cerebellum, the left superior and middle temporal gyri (BA21- [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38], and the bilateral middle and inferior frontal gyri (BA10-46). All these clusters were already hypometabolic before the treatment in comparison to those of the healthy control group (p<0.01).…”