BENGALURU: Infections, even those resulting from something as common as tooth decay, could have a strong concurrence with early onset of dementia, according to a slew of studies conducted of late. Experts in Bengaluru, while walking the road of sceptical caution, warn of the possible ramifications of the findings.

One of the latest forays into this involves a research conducted in Finland on lakhs of Finnish citizens. While the results make a strong distinction between correlation and causation, considering the findings to fall in the former category, it was found that severe cystitis, pneumonia or tooth decay could increase the risk of dementia. People or patients considered in the research pool who were treated at hospitals for these infections were found to be significantly more likely to develop dementia – including an early-onset form of the condition – within the next six years.

“This research holds ground in India perhaps even more acutely than in the West. In India, we have a high prevalence of chronic infections, including periodontal (gum) disease and urinary tract infections (UTIs), which often go undertreated due to a lack of awareness or access to preventive care. Given our ageing population, it is critical for Indian families to recognise that a sudden hospitalisation for an infection today could be the precursor to a neurological battle tomorrow,” says Dr. Usha Humbi, a consultant-neurologist at Narayana Health City.

While Dr. Humbi agrees that the findings can be verified as only correlative for now, she notes that there may exist a “plausible biological mechanism for causation.” “We often refer to the ‘two-hit hypothesis’: the first hit is the ‘silent’ buildup of amyloid plaques (the correlation), and the second hit is the ‘biological storm’ of inflammation (the potential cause of acceleration).

When a severe infection occurs, the body is flooded with cytokines. If these cross the blood-brain barrier, they can activate microglia (the brain’s immune cells), putting them into a state of chronic overdrive that kills healthy neurons. So, while the infection may not create dementia, it is likely to cause acceleration towards it,” she adds.

Even anecdotally, doctors claim that this is a trend that is consistent with the patients they treat. “It is not uncommon for patients or caregivers to report that cognitive or behavioural changes became noticeable after a severe infection or hospitalisation. These may present as confusion, memory difficulties, or a decline in overall functioning,” claims Dr. Priya Raghavan, a senior consultant-psychiatrist at Cadabams Hospitals.

This story is reported by Anubhab Roy