Objective:

Studies have shown that Anti-DPPX Encephalitis (DPPXE) can mimic CJD, with the difference being DPPXE has a gastrointestinal prodrome. In this case report, a patient with CJD presents with positive serum DPPX antibodies, following a prolonged GI prodrome and weight loss.

Background:

CJD shares similarities with DPPXE such as cognitive decline and neuropsychiatric symptoms, leading to misdiagnosis. Prion disease is linked to various autoantibodies, a suspected epiphenomenon of this disease process. In our review, there were no cases correlated with co-occurrence of DPPX antibodies and a clinical presentation similar to DPPXE.

Design/Methods:

NA

Results:

A 63-year-old female with history of intermittent diarrhea and unintentional weight loss presented with involuntary movements and rapidly progressive functional and cognitive impairment over the course of one month. MRI brain on hospitalization showed asymmetric cortical ribboning in the right cerebral hemisphere and left medial parietal lobe. EEG demonstrated right posterior quadrant LPDs with occasional right frontal sharp waves. Serum studies were drawn, which revealed positive DPPX antibodies. Patient was started on lacosamide and IV Solu-Medrol due to concerns for autoimmune encephalitis. Lumbar puncture showed normal protein and leukocyte count, later indicating negative DPPX receptor antibody on CSF evaluation. In the interim, patient was transitioned off Solu-Medrol due to steroid-induced psychosis and was started on IVIG. She experienced no benefit from IVIG, which was discontinued after positive RT-QuIC result confirmed the presence of prion disease. The patient continued to experience rapid neuropsychiatric decline and was moved to comfort care. She was deceased just over two months from symptom onset.

Conclusions:

Our case demonstrates the importance of considering autoantibodies as a possible epiphenomenon in the setting of clinical uncertainty between CJD and DPPXE. Given the paucity of data regarding these conditions, further studies may be warranted to optimize patient care and help expedite prognostic discussions.