Many people aren’t overly concerned when an octogenarian sometimes forgets the best route to his favorite store, can’t remember a friend’s name, or dents his car when trying to park on a busy street. Even healthy brains function less efficiently with aging, and memory, sensory perceptions and physical abilities become less reliable.
What if the person is not in their 80s, but in their 30s, 40s or 50s, and forgets the way home when they are on their own corner? It’s much more worrying. Most of the 5.3 million Americans living with Alzheimer’s disease or other forms of dementia are over 65, but about 200,000 under 65 develop serious memory and thinking problems much sooner than expected. .
“Dementia praecox is an especially discouraging diagnosis because it affects individuals in the prime of life,” wrote Dr. David S. Knopman, a neurologist at the Mayo Clinic in Rochester, Minnesota (USA), in a July 2021 editorial in the journal JAMA Neurology. Many of those affected are in their 40s or 50s, mid-career, poorly prepared for retirement and perhaps still raising families.
Dementia in a young adult is especially traumatic and challenging for families to recognize, and many doctors do not recognize it or even suspect that it may be an underlying cause of symptoms.
“Complaints about brain fog in young patients are very common and usually benign,” said Dr. Knopman. “It is difficult to know whether it is caused by stress, depression or anxiety, or a consequence of normal aging. Even neurologists rarely see patients with early dementia.”
However, recent studies indicate that the problem is much more common than most doctors realize. Worldwide, up to 3.9 million people under the age of 65 can be affected, according to an analysis of 74 studies. The analysis, done in the Netherlands and published in JAMA Neurology in September, found that for every 100,000 people between the ages of 30 and 64, 119 had early-onset dementia.
The editorial by Dr. Knopman called early dementia “an underappreciated problem”. His diagnosis is often delayed and knowledge about his treatment is also “scarce”, he wrote.
Various causes
The Dutch study found that, overall, Alzheimer’s disease was the most common cause of early-onset dementia. But when symptoms developed before age 50, early Alzheimer’s disease was a less likely explanation than two others: vascular dementia and frontotemporal dementia.
Vascular dementia results from a blockage or damage to blood vessels in the brain that interfere with circulation and deprive the brain of oxygen and nutrients. Its most common symptoms, in addition to memory problems, are confusion, difficulty concentrating, difficulty organizing ideas or tasks, and slow thinking.
In frontotemporal dementia, parts of the brain behind the forehead and ears shrink, resulting in drastic personality changes, socially inappropriate or impulsive behavior, and emotional indifference. Movement and memory problems often develop later in the course of the disease. According to the Mayo Clinic, frontotemporal dementia usually starts between age 40 and 65 and can be misdiagnosed as a psychiatric problem.
Lewy body disease is another cause of dementia in younger adults. It is associated with abnormal deposits in the brain of a protein called alpha-synuclein, which affects brain chemistry and causes behavioral, thinking and movement problems. Most symptoms are similar to those seen in other dementias, and other symptoms such as hallucinations can resemble schizophrenia, but the decline in brain function occurs significantly more quickly. A hallmark symptom of dementia with Lewy bodies is having violent dreams and trying to fulfill them, said Dr. Knopman.
Alzheimer’s disease remains the most common cause of dementia in both younger and older adults. There is an inherited form of Alzheimer’s that usually appears in younger people, but these cases account for less than 10% of early disease. Most cases of Alzheimer’s occur sporadically for unknown reasons, although genetic factors can increase the risk.
People with Alzheimer’s often have a buildup of abnormal substances in the brain — the proteins tau and beta-amyloid. Early symptoms include impaired memory, language problems, difficulty concentrating and completing tasks, poor judgment, and visual or spatial impairments that lead to problems such as errors when driving vehicles and locating yourself. Brain scans can reveal loss of brain cells and reduced ability to metabolize glucose, which is indicative of degenerative brain disease.
Probably the main factor responsible for increasing the risk of early dementia is repeated head injuries such as those experienced by professional boxers, football players, and sometimes, military veterans.
When brain cells are damaged or lost, there is no way to get them back. So avoiding head injuries is the best protection possible right now.
Many parents these days try to discourage young people from playing sports like football, where head injuries are common. However, the proper and constant use of helmets and not heading the ball in football can limit the risk of injury.
The Doctor. Knopman said he’s less concerned about elementary school kids playing these sports; the risk of developing dementia at a young age from repeated head trauma is much higher among people who played first division football or became professional boxers.
Among older people in general, the same inflammatory factors associated with atherosclerosis — the clogging and hardening of the arteries that supply the heart — can also affect the blood vessels that supply the brain. Body-wide inflammation linked to diabetes and heart disease can cause brain changes that promote dementia.
difficult diagnosis
Accurately diagnosing early dementia can be difficult, time-consuming, and should start with a detailed medical history, said Dr. Knopman. “If doctors don’t ask the right questions, families may fail to mention a telltale symptom, such as violent dreams.”
A thorough cognitive assessment of the person’s memory and language difficulties is critical, he said. Does she stumble over her words or does she say “white” when she means “black”? Neuropsychological tests can detect subtle difficulties with memory, visual, cognitive and executive functions.
A brain scan is needed to rule out the possibility that a tumor is causing the person’s cognitive symptoms. A spinal tap and spinal fluid analysis can reveal elevated levels of tau and beta-amyloid proteins in the brain. An MRI can show shrinkage of specific parts of the brain. And a glucose PET scan can find abnormal patterns of sugar absorption in various parts of the brain, which can help distinguish between Alzheimer’s disease, dementia with Lewy bodies and frontotemporal dementia.
“Different degenerative diseases of the brain have specific patterns of glucose uptake,” Knopman said.
As with older dementia patients, keeping young people with dementia safe is essential. They must no longer drive, operate hazardous equipment, including the stove, or be left unattended. Everyone must wear an identification tag day and night that alerts others to their condition.
Translated by Luiz Roberto M. Gonçalves
