Creutzfeldt-Jakob Disease (CJD) Diagnosed in Outpatient Psycho-oncology Clinic: A Zebra or Sign for More Vigilance?

Abstract:

Background: Creutzfeldt-Jakob disease (CJD) is a rare, rapidly progressive, and invariably fatal neurodegenerative disorder caused by the presence and proliferation of prion proteins. CL psychiatrists may consider this diagnosis in the inpatient setting when presented with a patient with unexplained mood, behavior, and cognitive changes. Here we discuss a case who presented in the outpatient setting with strong psychiatry advocacy leading to the correct diagnosis of CJD.

Case: We present a case of a 65-year-old man with history of high-grade dysplasia of the oral cavity and invasive squamous cell carcinoma of the right mandibular gingiva. He was referred to outpatient psychosocial oncology for “forgetfulness, decreased attention, confusion and borderline hallucination”. He was a well-educated, happily married man with no prior psychiatric or substance use history. Assessment revealed three months of worsening bizarre behaviors concurrent with increasing falls, hypersomnolence, and dream enactment. He demonstrated myoclonic jerking movements on home video. He scored 21/30 on the Montreal Cognitive Assessment (MoCA) with deficits noted in visuospatial and executive functioning, attention, language, delayed recall, and orientation. CT scan of his head a month prior was unremarkable, but brain MRI two days after this assessment showed hyperintensity in the bilateral caudate nuclei, putamen, thalamus, and cingulate gyri, with left parietal cortical ribboning. CSF was positive for RT-QuIC, and there was no mutation noted with the PRNP gene. The patient was referred to hospice, where he continued to decline, and died 6 months after his diagnosis.

Discussion: Our patient developed sporadic CJD as evidenced by positive RT-QuIC and negative PRNP mutation. Of the approximately 350 cases in the United States each year, 85% of CJD cases occur sporadically due to spontaneous transformation of prion proteins, and the remaining cases are due to an inherited mutation of the prion protein. Although this patient demonstrated a classic presentation of CJD, his confounding medical factors, including cancer diagnosis with subsequent comorbidities and polypharmacy, and the rare occurrence of this disease impacted his diagnosis. Psychiatrists are commonly involved in the care of these patients before the diagnosis of CJD is made because they often present with mood changes, sleep disturbances, psychosis, and cognitive deficits. It is imperative that psychiatrists working in all settings maintain an open differential diagnosis even when working with already medically complex patients. A detailed history collection, careful physical/neurological examination, and high level of suspicion can lead to the correct diagnosis.

Conclusion: Rapidly advancing dementia with neuropsychiatric symptoms and abnormal movements should raise suspicion of CJD. Appropriate medical workup can conclusively prove the diagnosis. Treatment is supportive and outcomes are invariably fatal. Psychiatrist can have an important role to play in the diagnosis of CJD.