A case of semantic variant primary progressive aphasia with severe insular atrophy

Abstract

Insular degeneration has been linked to symptoms of frontotemporal dementia (FTD). Presented in this case is a patient exhibiting semantic variant primary progressive aphasia, behavioral disturbance. Upon autopsy, he was found to have severe insular atrophy. In addition, selective serotonin reuptake inhibitors were ineffective in reducing symptoms of obsessive-compulsive behaviors or emotional blunting. This case suggests that Seeley et al.'s (2007 , Alzheimer Disease & Associated Disorders, 21, S50) hypothesis that von Economo neurons and fork cell-rich brain regions, particularly in the insula, are targeted in additional subtypes of FTD beyond the behavioral variant.

Figure 1

T1-weighted coronal section MRI at 10 years into illness shows marked temporal greater than frontal atrophy, as well as insular atrophy. The atrophy is also asymmetric, worse on the right than on the left. Also note involvement of the hippocampi.

Figure 2

H and E stained sections of insular cortex from an individual with no neurocognitive abnormalities, photographed at low (a1) and high (b1) magnification Center panels a2 and b2 show insular cortex from a patient with Alzheimer disease. Panels at right (a3 and b3) show insular cortex from the patient described in this case report, with most marked neuron loss and pronounced astrocytic gliosis.

Figure 3

Sections of insular cortex from patient described in this case report. Note occasional plaque-like distribution of tau-immunoreactive neurites, a rare finding within the cortex (a), thread-like ubiquitin-immunoreactive processes in the neuropil throughout all cortical regions (including insula) (b,c) and prominent TDP-43 immunoreactivity of cytoplasmic inclusions, apparently within neuronal cell bodies (d).