Falls can be scary for anybody. For an older person it can herald a loss of confidence that makes them cautious about moving around.

This leads to more muscle loss and weakness, and the person being more vulnerable to falling again.

The numbers aren’t encouraging. One in four people who are aged 65 and over have at least one fall per year.

There are different reasons why older people fall.

Difficulties with balance, weaker muscles that may make it harder to lift your feet when you walk, poorer eyesight, slower reaction times and new health problems such as incontinence can all lead to a fall.

But a fall can also be a sign of something more profound at work.

The mystery of falling and dementia

Researchers from Brigham and Women’s Hospital have found that “among older adults who sustained a traumatic injury, those who experienced falls were more likely to be subsequently diagnosed with Alzheimer’s disease and related dementias.”

The study involved more than 2 million older adults who’d sustained an injury. Of these, 10.6 per cent (more than one in ten) who’d suffered a fall were subsequently diagnosed with some form of dementia.

Overall, dementia was more frequently diagnosed within one year of a fall compared to other types of injuries.

The researchers recommend “implementing cognitive screenings in older adults who experience an injurious fall that results in either an emergency department visit or admission to the hospital”.

Results are published in JAMA Network Open.

The mystery question is: does the fall cause the dementia, or does the dementia cause the fall?

In its reporting on the study, Medical News Today observes:

“Some types of dementia, such as Alzheimer’s disease, result from the progressive death of brain cells and neurons. It develops and worsens over time.

“But head injuries can contribute to dementia through the damage to cells directly.”

Some types of traumatic brain injury – particularly if repetitive, such as occur in sports – “may increase the risk of certain types of dementia later in life”.

What the researchers say

Dr Molly Jarman is assistant professor in the Department of Surgery at the Brigham. She is the senior author of the study. She said:

“The relationship between falls and dementia appears to be a two-way street.

“Cognitive decline can increase the likelihood of falls, but trauma from those falls may also accelerate dementia’s progression and make a diagnosis more likely down the line.”

Thus, she said, falls “may be able to act as precursor events that can help us identify people who need further cognitive screening”.

Dr Alexander Ordoobadi is a resident physician in the Department of Surgery at the Brigham, and first author. He said:

“We treat the injuries, provide rehabilitation, but often overlook the underlying risk factors that contribute to falls”.

This is despite “a growing body of evidence suggesting a link between falls and cognitive decline”.

He said that ideally, after an injury, “older adults should receive follow up care with a primary care provider or geriatrician who can monitor their cognitive health and long-term functional recovery after the injury”.