Clinical diagnosis of human prion disease

A case report of fatal familial insomnia with cerebrospinal fluid leukocytosis during the COVID-19 epidemic and review of the literature

Fatal familial insomnia (FFI) is a rare autosomal dominant genetic neurodegenerative disease. Generally, FFI patients will develop rapidly progressive dementia, sleep disturbance, autonomic dysfunction, and so on. Cerebrospinal fluid examination of FFI patients normally shows no obvious abnormalities. Here, we report a young male patient who was diagnosed with FFI during the COVID-19 epidemic. Clinical symptoms include psychobehavioral abnormality, cognitive decline, sleep disturbance, and autonomic dysfunction. No abnormalities were found in routine examinations after admission. However, the number of white blood cells in the cerebrospinal fluid increased. Though the patient was treated with anti-infection and immunotherapy, the symptoms were not relieved. A lumbar puncture was performed again, and it was found that the total Tau protein in the cerebrospinal fluid was elevated, and PET results showed that brain metabolism decreased. Finally, a genetic test was used to confirm the diagnosis of FFI. This case suggests that patients with FFI may also have elevated white blood cells in cerebrospinal fluid and timely detection of Tau protein in cerebrospinal fluid is helpful for early identification of FFI. And precise diagnosis relies on genetic testing.

Organoids for modeling prion diseases

Human cerebral organoids are an exciting and novel model system emerging in the field of neurobiology. Cerebral organoids are spheres of self-organizing, neuronal lineage tissue that can be differentiated from human pluripotent stem cells and that present the possibility of on-demand human neuronal cultures that can be used for non-invasively investigating diseases affecting the brain. Compared with existing humanized cell models, they provide a more comprehensive replication of the human cerebral environment. The potential of the human cerebral organoid model is only just beginning to be elucidated, but initial studies have indicated that they could prove to be a valuable model for neurodegenerative diseases such as prion disease. The application of the cerebral organoid model to prion disease, what has been learned so far and the future potential of this model are discussed in this review.