Abstract Details

Title A Devastating Neurologic Disorder: Anti-Dipeptidyl Peptidase like Protein-6 Encephalitis Mimicking Creutzfeldt-Jakob Disease

Topic Autoimmune Neurology

Presentation(s) P11 - Poster Session 11 (11:45 AM-12:45 PM)

Poster/Presentation
Number 9-002

Background Rapidly progressive dementia is caused by a heterogenous group of neurological disorders, and the prototype is CJD. However, treatable causes including autoimmune encephalitis are often under recognized and under-treated.

Objective We present a patient with rapidly progressive dementia, neuropsychiatric disorder, rigidity, and startle myoclonus. Clinically thought to be Creutzfeldt-Jakob Disease (CJD) initially, she was eventually diagnosed with Anti-Dipeptidyl Peptidase like Protein-6(DPPX) encephalitis.

Design/Methods NA

Results 72-year-old female with medical history of hypertension, ovarian teratoma post resection in 2000's was admitted with rapidly progressive cognitive decline over 9 months. In the initial course of illness patient had severe anxiety, depression, visual hallucinations and paranoid behavior. Profound 40-pound unintentional weight loss and seizures were also reported. On neurological exam patient was only oriented to self, she had exaggerated startle response with diffuse rigidity. Comprehensive laboratory testing, serum autoimmune panel including thyroid peroxidase and thyroglobulin antibodies were negative. EEG showed mild to moderate diffuse slowing without any epileptiform abnormalities. MRI brain revealed significant hippocampal atrophy, per NeuroQuant. Evaluation for malignancy was negative. CSF analysis showed mild lymphocytic pleocytosis, elevated protein, four oligoclonal bands, but negative RT-QUIC and 14-3-3 protein. Patient received 5 days of IV steroids followed by a course of IVIG without significant improvement. Initial autoimmune encephalitis panel was reported as negative but later a test done on research basis by laboratory came back positive for DPPX antibody in serum and CSF. However, patient passed away before additional treatment could be attempted.

Conclusions Anti-DPPX encephalitis is a rare autoimmune disorder and is potentially treatable if recognized early in the course of disease. Clinical features such as rapidly progressive cognitive decline, neuropsychiatric disorder, rigidity, and exaggerated startle myoclonus could mimic CJD. Anti-DPPX encephalitis can be refractory to first line immunotherapies. Early diagnosis and rapid escalation of treatment are imperative to avoid devastating neurological consequences.

Authors/Disclosures
Neeharika Thottempudi, MD PRESENTER	Dr. Thottempudi has nothing to disclose.
Aimalohi Esechie, MD, PhD (SLUH)	Dr. Esechie has nothing to disclose.
Chilvana V. Patel, MBBS, FAAN	Dr. Patel has nothing to disclose.
Elena Shanina, MD, FAAN (University of Texas Medical Branch, Neurology Department)	Dr. Shanina has nothing to disclose.
Xiangping Li, MD, FAAN (University of Texas Medical Branch (UTMB))	Dr. Li has nothing to disclose.