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Background Emergence of visual and musical creativity in the setting of neurologic disease has been reported in patients with semantic variant primary progressive aphasia (svPPA), also called semantic dementia (SD). It is hypothesized that loss of left anterior frontotemporal function facilitates activity of the right posterior hemispheric structures, leading to de novo creativity observed in visual artistic representation. We describe creativity in the verbal domain, for the first time, in three patients with svPPA. Methods Clinical presentations are carefully described in three svPPA patients exhibiting verbal creativity, including neuropsychology, neurologic exam, and structural MRI. Voxel based morphometry (VBM) was performed to quantify brain atrophy patterns in these patients against age-matched healthy controls. Results All three patients displayed new-onset creative writing behavior and produced extensive original work during the course of disease. Patient A developed interest in wordplay and generated a large volume of poetry. Patient B became fascinated with rhyming and punning. Patient C wrote and published a lifestyle guidebook. An overlap of their structural MR scans showed uniform sparing in the lateral portions of the language-dominant temporal lobe (superior and middle gyri) and atrophy in the medial temporal cortex (amygdala, limbic cortex). Conclusions New-onset creativity in svPPA may represent a paradoxical functional facilitation. A similar drive for production is found in visually artistic and verbally creative patients. Mirroring the imaging findings in visually artistic patients, verbal preoccupation and creativity may associate with medial atrophy in the language-dominant temporal lobe but sparing of lateral dominant temporal and non-dominant posterior cortices.

IntroductionThe Behavioral Inhibition System (BIS) and the Behavioral Activation System (BAS) have been theorized as neural systems that regulate approach/withdrawal behaviors. Behavioral activation/inhibition balance may change in neurodegenerative disease based on underlying alterations in systems supporting motivation and approach/withdrawal behaviors, which may in turn be reflected in neuropsychiatric symptoms.MethodA total of 187 participants (31 patients diagnosed with behavioral variant of FTD [bvFTD], 13 semantic variant of primary progressive aphasia [svPPA], 14 right temporal variant FTD [rtFTD], 54 Alzheimer’s disease [AD], and 75 older healthy controls [NCs]) were included in this study. Changes in behavioral inhibition/activation were measured using the BIS/BAS scale. We analyzed the correlation between regional atrophy pattern and BIS/BAS score, using voxel-based morphometry (VBM).ResultsADs had significantly higher BIS scores than bvFTDs and NCs. bvFTDs activation-reward response (BAS-RR) was significantly lower than ADs and NCs, though their activation-drive (BAS-D) was significantly higher than in ADs. Both AD and rtFTD patients had abnormally low activation fun-seeking (BAS-FS) scores. BIS score correlated positively with right anterior cingulate and middle frontal gyrus volume, as well as volume in the right precentral gyrus and left insula/operculum.ConclusionsAD, bvFTD, and rtFTD patients show divergent patterns of change in approach/withdrawal reactivity. High BIS scores correlated with preservation of right-predominant structures involved in task control and self-protective avoidance of potentially negative reinforcers. Damage to these regions in bvFTD may create a punishment insensitivity that underlies patients’ lack of self-consciousness in social contexts.