Case presentation
A 51 year-old woman was transferred from the regional hospital to the Neurology department of the University hospital due to over a two week history of an advancing speech abnormalities characterized by difficulty in retrieving words and producing structured sentences, involuntary repetition of the same words or phrases. Most common diagnosis of acute cerebrovascular event was ruled out after normal CT scan. Due to Covid-19 pandemic and strict quarantine rules, family members were not allowed to visit the patients in the hospital, which made gathering anamnestic facts rather difficult. Recurrent expedient phone call conversations with patient’s family members revealed that first symptoms were noticed about three months prior hospitalization. She had trouble concentrating and had impaired short-term memory which resulted in her doing same actions repeatedly (e.g. bringing multiple cups of coffee or meals to her husband), she did not answer questions sensibly and looked mildly confused.
Past medical history was significant for hypertension. Otherwise the patient was physically active and worked as an accountant.
At the time of hospitalization, neurological examination revealed disorientation in space and time. She seemed noncritical of her condition, had inadequate emotions (e.g. kept smiling or laughing at questions about her health), and was unable to follow commands on neurological examination. She had severe sensorimotor aphasia and could not tell her name or formulate her complaints. Palilalia, echolalia, apraxia, acalculia, agraphia were present. The rest of the examination was unremarkable: cranial nerves, motor and sensory systems were intact, no pathologic or primitive reflexes were found. There were no signs of either extrapyramidal or cerebellar dysfunction and no myoclonus.
Patient used valsartan/hydrochlorothiazide and metoprolol for her hypertension. There was no reported alcohol, illicit drug use or possible contact with chemicals or heavy metals.
On the day of the admission, brain magnetic resonance imaging (MRI) did not show any signs of ischemia, tumor or other possible structural cause of her symptoms.
Patient underwent a broad investigation for differential diagnosis - tests were performed to rule out encephalopathy of various origin, i.e., hepatic, renal, thyroid, vitamin deficiencies, and any possible vascular, infectious, paraneoplastic, and autoimmune etiology of the previously mentioned symptoms. Laboratory tests included a complete blood count, a comprehensive metabolic panel, vitamin B12, folates, thyroid-stimulating hormone, which were all unremarkable. Tests for sexually transmitted diseases (i.e. syphilis and HIV), borreliosis, tick-borne encephalitis, onconeural and antineuronal antibodies were negative. Lumbar puncture was performed in order to eliminate neuroinfection as a possible diagnosis; CSF analysis did not show any pleocytosis, while glucose and protein levels were within normal limits.
Neuropsychological testing with Mini-Mental State Examination (MMSE) and a clock drawing test returned scores of 0, showing significant impairment of cognitive functions including short-term memory, attention, concentration, writing, reading, calculating, and constructional praxis.
In the course of the next 2 weeks she suffered severe cognitive decline, could no longer eat or go to the bathroom on her own, and replied with one-word nonsensical answers.
On day 15 in the Neurology department, a second brain MRI was performed. It revealed very subtle cortical T2W/FLAIR hyperintensities, best appreciated in the right parietal cortex, and subtle but more extensive abnormalities on diffusion-weighed imaging, showing signs of diffusion restriction in both the cortical and deep grey matter, including bilateral cortical regions (best appreciated in the right parietal and left parieto-occipital cortices), caudate nuclei, and anterior putamina (Figure 1). MRI findings were suggestive of typical sCJD, with possible (but less likely) differential diagnoses including autoimmune encephalitis and other systemic encephalopathies of various etiologies.