A 56 year-old man originally presented to memory clinic for one year of gradually progressively decreased speech production, increased impulsivity, and difficulty navigating in a car. At that time, his exam was notable for expressive aphasia, difficulty with Luria hand motions and a shuffling gait.  MRI of the brain initially showed asymmetric left temporal-lobe atrophy. FDG-PET showed decreased uptake in the basal ganglia with symmetric cortical uptake.  A neuropsychiatric evaluation showed mild impairments in attention and working memory with more prominent impairments in memory, language, and visuospatial function. A diagnosis of frontotemporal dementia was rendered.  Over the next two years he developed anarthria, right arm rigidity with dystonic posturing, apraxia, dysphagia, and balance impairments. The clinical diagnosis was revised to corticobasal syndrome.  The patient passed away three years into his illness at age 58.

The fixed brain weighed 1088g.  Frontal horn dilation with caudate and putaminal atrophy was noted. Neuron loss and gliosis was noted in the frontal lobes, hippocampus, and substantia nigra.  Tau (PHF-1) amyloid-beta, phosphorylated alpha-synuclein, and TDP-43 immunohistochemistry did not show any pathologic inclusions. Immunohistochemistry for ubiquitin and FUS showed dentate granule cells with both oval cytoplasmic inclusions and curvilinear intranuclear inclusions most consistent with aFTLD-U.