The 61-year-old NY man was brought to hospital after he had difficulty thinking, was losing touch with reality and he couldn't walk by himself, according to a case report presented to an infectious diseases forum last week.
Doctors at Rochester Regional Health wrote in a report presented at the conference there were four suspected cases of the rare disease in a six-month period. Most of these cases have been linked to consumption of contaminated beef in the United Kingdom in the 1980s and 1990s.
"'All of them were squirrel-brain eaters, " a doctor told the paper at the time.
"It's unclear if the man consumed the entire squirrel brain or just squirrel meat that was contaminated with parts of squirrel brain", the report's lead author said.
The disease is always fatal, according to the National Institute of Health (NIH).
Doctors discovered he developed a degenerative disease caused by the same infectious proteins that also result in the more infamous "mad cow disease".
The rarest form is acquired CJD, which is when the brain or nervous system tissue becomes infected through exposure - only causing one percent of cases.More news: Russian Woman Charged with US Election Interference
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A 61-year-old who experienced a severe cognitive decline before his death may have had squirrel brains to blame.
Though current tests can distinguish vCJD from the classical form of the disease, Chen told Live Science that it's unknown whether the man was definitively diagnosed with CJD.
Symptoms of CJD usually begin to appear around age 60 and include depression, anxiety, memory loss, personality changes, impaired thinking, difficulty swallowing and difficulty speaking. There is no treatment or cure for the disease.
Most people who contract it only live around a year.
Of the five cases detailed in their report, however, two were eventually confirmed not to be CJD after all.
Dr. Tara Chen came across the unusual case when she was tasked with doing a report on cases of CJD seen at the hospital over the last five years.
However, CJD can be confirmed only with a test of brain tissue on autopsy at death.