An Autopsy Case of a Patient With Corticobasal Degeneration and a History of Acute Restlessness and Stupor

Some patients with corticobasal degeneration (CBD) present with neuropsychiatric symptoms, including frontal lobe symptoms. However, stupor is rarely reported. Here, we report a case of acute restlessness at onset, which was clinically diagnosed as frontotemporal dementia (FTD) but was found to be CBD at autopsy. A 71-year-old woman with COVID-19 presented to our hospital. At the age of 62, she had suddenly become restless and confused without any preceding motor or psychiatric symptoms. She was treated with psychotropic drugs but subsequently entered stupor and was admitted to a psychiatric hospital. Magnetic resonance imaging showed mild atrophy of the frontal lobe. Single-photon emission computed tomography showed decreased blood flow in the frontal lobe, and the patient was clinically diagnosed with FTD. At the age of 71, she was transferred to our hospital from a psychiatric hospital for COVID-19 treatment. Upon transfer to our hospital, the patient presented with akinetic mutism. The patient died of respiratory failure 10 days after the onset of COVID-19. Immunostaining with AT8 and RD4 antibodies revealed astrocytic plaques, pretangles, coiled bodies, and threads, predominantly in the frontal lobes and basal ganglia. Other pathologies include accumulation of pTDP43 in the basal ganglia, thalamus, and frontal lobes. Argyrophilic grains were observed in the amygdala and the hippocampus, which corresponded to Saito stage 2. Other neurodegenerative proteins, such as amyloid β or α-synuclein, were not observed. The patient was pathologically diagnosed with CBD. We present a rare autopsy case involving a patient with CBD who presented with acute psychiatric symptoms and stupor. The psychiatric symptoms were characterized by agitation and fear-related behavior, which differ from the disinhibition and antisocial behavior typically associated with frontal lobe symptoms. Further autopsies are needed to examine the extent of tau pathology spread and accumulation to better understand the psychiatric symptoms of CBD.