Case Presentation: A 54-year-old female with a history of alcohol abuse and anxiety was admitted for 1 month of progressive altered mental status preceded by visual hallucinations. Over that time period, her symptoms rapidly progressed to agitation, dementia, and personality change. Physical symptoms included left elbow rigidity, startle myoclonus, and gait ataxia. Laboratory workup was negative for thyroid dysfunction, infection, paraneoplastic syndrome, autoimmune encephalitis, inflammatory process, malnutrition, heavy metals, drug toxicity, and metabolic derangement. Imaging workup was negative for acute process on CT of the head, CT of the abdomen/pelvis, and chest x-ray. Cessation of paroxetine failed to improve symptoms.Neurology was consulted for possible seizure activity. Continuous EEG showed moderate diffuse slowing and copious triphasic waves. MRI of the brain showed scattered white matter demyelination likely due to microvascular change, although a primary demyelinating process could not be excluded. Lumbar puncture was negative for fungal, bacterial, and viral meningitis/encephalitis etiology. While CSF markers for CJD were pending, psychiatry was consulted with subsequent lorazepam challenge negative for catatonia.On hospital day 7, the patient became agitated, non-verbal, and disoriented to self, location, and time. In coordination with palliative care, the family elected to begin comfort care. The patient was ultimately discharged to an outpatient hospice facility. Five days after discharge, the final CSF results showed elevated protein 14-3-3, elevated total tau protein, and positive Real-Time Quaking-Induced Conversion (RT-QuIC). Correlation of clinical symptoms, EEG findings, and CSF markers strongly supported a diagnosis of HV-CJD.

Discussion: CJD is a rare neurodegenerative disease caused by pathologic prions, with incidence approximated at 1-2 cases per million individuals. Most cases present with neuropsychiatric decline, startle myoclonus, ataxia, and aphasia. Diagnostic workup includes brain MRI, EEG, and lumbar puncture with CSF evaluation of protein 14-3-3, total tau protein, and RT-QuIC. These diagnostic modalities are 97.8% sensitive when all are performed. In this case, the involvement of antecedent visual hallucinations in the absence of ocular disease suggested the presence of HV-CJD, in which prions display neurotropism for the occipital lobe. HV-CJD accounts for only 3.7-4.9% of all CJD cases. Prognosis is poor as death typically occurs within one year of symptom onset.

Conclusions: This case highlights several considerations for clinicians. First, the importance of utilizing clinical suspicion to expedite patient management while awaiting confirmatory testing. The patient’s transition to palliative care was accomplished quickly due to high clinical suspicion for CJD in the absence of alternative diagnosis. Further, multidisciplinary management was imperative for ruling out alternative diagnoses, implementing appropriate diagnostic workup, and transitioning to hospice. Finally, despite the rarity of HV-CJD, it must be considered in patients with visual changes followed by rapidly declining neuropsychiatric status and startle myoclonus.