The Importance of Long-term Partner Observation in Cognitive Evaluation: A Very Early Creutzfeldt-Jakob Disease in a Patient with Mild Cognitive Impairment.

Background: Creutzfeldt-Jakob disease (CJD) is a fatal degenerative brain disease characterized by rapidly progressive dementia. Sporadic CJD (sCJD) is the best-known and most common subtype. Because the disease is uncommon and has highly diverse presenting symptoms, early diagnosis is challenging. We herein report a case of probable sCJD diagnosed at a very early stage.

Case presentation: A 61-year-old female patient had mild attention and memory problems for a few months that were noticed by her husband but did not bother her and did not affect her daily life activities. The first brain magnetic resonance imaging (MRI) at another hospital was normal, lacking diffusion-weighted imaging (DWI). Although the newly taken brain MRI without DWI was normal, the patient's husband brought his patient to our outpatient clinic because he continued to think that there was a difference in his wife's attention and memory. A neurological examination of the patient revealed almost normal findings. The neuropsychiatric evaluation of the patient was consistent with mild cognitive impairment. The patient's electroencephalography taken upon admission had no characteristic findings for CJD but showed generalized epileptiform activity. Therefore, the patient was hospitalized, and a second brain MRI, including DWI sequences, was performed. DWI displayed bilateral asymmetrical typical patterns of restricted diffusion. Cerebrospinal fluid 14-3-3 was positive, and total-tau was highly elevated. She had a diagnosis of probable sCJD at an early stage. Later, the patient developed progressive dementia, ataxia, seizures, and extrapyramidal symptoms, followed by mutism, and died.

Conclusion: Although there is no cure for CJD today, early diagnosis is essential, mainly because of its potential infectivity and for future planning. Diagnosing sCJD in its early stages is difficult. However, taking into account the observations of not only the patient's history but also their longterm partners in cognitive evaluations will be helpful in making an early and accurate diagnosis.