- New research finds that difficulty navigating while walking could be an early sign of Alzheimer’s disease.
- Early signs of Alzheimer’s disease include short-term memory loss, word-finding difficulties, difficulty planning complex tasks or solving problems and changes in mood or personality.
- Experts are using biomarkers such as amyloid-beta and/or tau to look for early signs of Alzheimer’s disease.
Research published on October 11 in the journal
Researchers said that “impaired path integration,” which involves understanding distance and direction in order to sense your location, could be a sign of early Alzheimer’s disease (AD).”
Researchers investigated walking difficulties as a sign of Alzheimer’s with a virtual reality model of the walking patterns of healthy older adults. This VR model could then be compared with people with mild cognitive impairment (MCI).
The researchers examined healthy younger and healthy older individuals and older people with mild cognitive impairment.
Compared to those without mild cognitive impairment, the main distinguishing factor of those with mild cognitive impairment was a lack of understanding of spatial recognition and incorrectly sensing or accurately gauging their location.
Path integration deals with the cognitive ability to understand where you are in a space and how to move in that space.
According to Dr. John Dickson, PhD, a neurologist in the Memory Disorders Unit in the Department of Neurology at Massachusetts General Hospital, path integration deals with the cognitive ability to know where a person is in space and how they are moving (speed, direction, etc.).
It also involves calculating how movements may need to change in response to where they are and where they want to go and planning the movements needed to adjust their trajectory.
There are key parts of the brain that deal with path integration that are affected early on by Alzheimer’s, according to Dickson, including the entorhinal cortex.
“This part of the brain contains special cells that are called ‘grid cells.’ Grid cells help people understand their position in space, similar to the way a grid can aid with localization in a two-dimensional plane. Grid cells can integrate information like location, distance, and direction.”
Since the entorhinal cortex is affected early in Alzheimer’s disease, it is reasonable to assume the grid cells would also be affected, leading to impaired function regarding navigation.
In addition to the entorhinal cortex the parietal lobes are also affected in Alzheimer’s disease, Dickson added.
The parietal lobes are important for being able to visually understand the spatial relationships of objects, which can also impact navigation.
“One of the targeted brain regions in [Alzheimer’s] is the parietal lobe which is involved in spatial orientation of the body which probably interferes with knowing how a person is oriented,” Dr. Andrew Newberg, neuroscientist and director of research at the Marcus Institute of Integrative Health and a physician at Jefferson University Hospital, told Healthline. Newberg was not involved in the study.
“[Alzheimer’s] also affects the temporal lobes which has structures involved in body sensation so if that is affected, you will have trouble turning and knowing where your body is.”
Dickson added that more research needs to be done to understand exactly which parts of the brain are being impacted early on.
“While the authors generally think the grid cells in the entorhinal cortex may be particularly involved in their findings, this study does not specifically demonstrate that changes in grid cells mediate the deficits noted,” Dickson said.
“The authors note that further research is needed to determine the exact changes in the brain that cause the deficits in path integration they see in this study.”
Short-term memory loss is the most common
Other early symptoms may include:
- losing track of dates or not knowing current location
- word-finding difficulties
- difficulty planning complex tasks or solving problems
- changes in mood or personality
It’s also important to note that in some cases, the symptoms may overlap with normal age-related cognitive changes in the earliest stages, so it can sometimes be difficult to distinguish between typical aging and Alzheimer’s disease, Dickson explained.
If people have concerns about cognitive changes, it is worth discussing them with their doctor to see if further evaluation is needed.
“The family members and loved ones of AD patients would often express concern about patient’s increasing difficulties to smoothly navigate in familiar locations, manifested as episodes of disorientation and even getting lost in familiar locations,” said Dr. Arman Fesharaki-Zadeh, PhD, assistant professor of psychiatry and of neurology, medical director of dementia and behavioral Neurology at Yale School of Medicine. Fesharaki-Zadeh was not involved in the study.
“Episodic memory deficits could be described as difficulties with recall of recent conversations or events and asking a same question about the content of a recent discussion repeatedly.”
In recent years, healthcare experts have developed more accurate ways to diagnose Alzheimer’s.
The presence of amyloid and phosphoylated Tau in cerebrospinal fluid (CSF) now allows diagnostic confirmation of AD, even in early stages, with high levels of accuracy, Dr.Ana Vives-Rodriguez, a movement disorders and cognitive-behavioral neurologist at Yale Medicine told Healthline.
“Alzheimer’s disease biomarkers of amyloid-beta and/or tau are growing in their use and importance in the clinical diagnosis of patients in the early stages of Alzheimer’s disease,” Dickson noted.
These biomarker tests are done after a lumbar puncture to obtain cerebrospinal fluid (CSF) from which the amyloid-beta and tau levels can be measured.
Imaging-based approaches with positron emission tomography (PET) for assessing the amyloid-beta or tau burden in the brain have also been developed and approved for use by the Food and Drug Administration (FDA).
However, due to a lack of insurance coverage for these tests, their use is exceedingly rare for most people. But, they are increasingly being used in research studies.
The Centers for Medicare and Medicaid Services (CMS) has announced a draft decision to provide coverage for amyloid PET scans.
If CMS finalizes this decision and provides coverage for clinical amyloid PET scans, their clinical use will likely increase.
Blood-based biomarkers for amyloid-beta and tau have also been developed, though their development is a bit behind other biomarker testing, they have not gained widespread clinical use yet.
Eventually, however, they may become an easy way to obtain biomarker information since it will only involve a blood test.
Aside from these biomarkers, other diagnostic evaluations for Alzheimer’s disease include a thorough medical history and examination, cognitive testing, and magnetic resonance imaging (MRI) of the brain, Dickson added.
If you have concerns about cognitive symptoms, it is important to discuss these with their doctors to determine if further evaluation is needed.
A current topic of interest to many patients with Alzheimer’s disease is anti-amyloid therapy, which is a new class of medications that help remove amyloid-beta from the brain, Dickson stated.
While there is no cure for the disease in recent months new drugs have arrived on the market to help delay symptoms.
One of these medications, lecanemab, received full approval by the FDA earlier in 2023.
However, it is important to note this medication has some potentially serious side effects, including swelling or bleeding in the brain, so the decision to start this medication should be made with careful consideration.
“Patients should discuss with their doctors right away if they have noticed changes in their thinking and memory. Alzheimer’s disease is not the only cause of changes in memory and thinking and your doctor should order blood work and brain imaging to rule out alternative causes,” said Vives-Rodriguez.
In addition, tests that evaluate thinking and memory are essential to detect subtle memory and thinking changes that might be more than what would be expected for age. Brief screening tests are usually part of the assessment your primary care doctor would complete in the office.
If further concerns are present, a formal neuropsychological testing might be requested to be completed by a neuropsychologist.
Finally, if there are persistent concerns, an evaluation from a neurologist would be very helpful to further assess for the possibility of Alzheimer’s disease or other neurological disorders that could present with cognitive changes, Vives-Rodriguez added.
A neurologist would further guide the patient toward advanced testing that could assist in an early AD diagnosis and treatment.
A new study finds that difficulty navigating while moving and walking can reveal early indications of Alzheimer’s disease.
Aside from trouble with directions, additional early signs of AD include short-term memory loss, word-finding difficulties, difficulty planning complex tasks or solving problems and changes in mood or personality.
Biomarkers of amyloid-beta and/or tau are becoming more widely used to diagnose patients in the early stages of AD.