Does essential tremor (ET) come with a greater risk of aging-related cognitive problems such as forgetfulness or less ability to organize a task? As I have previously written, researchers have mixed opinions. The fact that many aging adults experience reduced short-term memory or temporary confusion over what day it is poses a challenge in terms of sorting out any connection between ET and cognitive decline.
Brain changes or simply distraction?
Some types of cognitive impairment are due to changes in the brain as people age. Dementia and Alzheimer’s disease, for example, begin to occur with the misfolding of some types of proteins in the brain, or an accumulation of others. There is physical evidence of this from autopsies of patients’ brains. Today, much research is devoted to developing diagnostic imaging or blood tests for biomarkers if early symptoms occur.
However, there does not appear to be a solid correlation between the abnormal brain messages that lead to ET and the types of toxic changes in the brain that are known to cause cognitive dysfunction. Yet some studies have demonstrated that older individuals with ET seem more vulnerable to functional cognitive disorder (FCD or simply “brain fog”) than matched controls.
A May, 2018 review and analysis of published evidence suggests that individuals with chronic or progressive neurological conditions may lose some mental crispness not because of physical brain deterioration but rather because having a problematic condition is distracting.
A unifying theory
The article by Teodoro, et al. proposes that functional cognitive abnormalities (that is, measurable decreased mental abilities not attributed to physical brain changes) are related to the fact of living with distraction.i Here are the specific conditions they identify for their purposes:
- Fibromyalgia – widespread muscular and skeletal pain often accompanied by sleep problems and cognitive symptoms
- Chronic fatigue syndrome – long term, persistent incapacitating fatigue and weakness with no apparent physical cause
- Functional neurological disorders – includes movement disorders such as ET, and sensory disorders. The brain appears normal but has dysfunctional signals with no known cause.
Just looking at that list, it is very understandable that the daily act of living and coping with any one of these conditions would literally “siphon off” a person’s attention. Each of these conditions places demands on a person to continually adapt.
The Teodoro paper found a great deal of variability in how each of these conditions affected mental functions such as memory, learning, organizing and fulfilling tasks, absent-mindedness, disrupted flow of thoughts and verbal conversations, etc. Collectively, all the conditions are, to one degree or another, “…associated with similar, prominent cognitive symptoms, including forgetfulness, distractibility and word-finding difficulties.”ii They also point out that some of the medications used to manage the conditions may have side effects that contribute to a sense of brain fogginess.
While the authors do not propose practical strategies for overcoming displaced attention, perhaps training that encourages serene mindfulness, such as meditation, can help redirect a person’s focus. Many people with ET find that the more they concentrate on controlling tremors while trying to do things like button a shirt or drink a glass of water, the worse the tremors are. Instead, having a mental discipline that refocuses and enlarges the brain’s sense of perspective may help to lower the stress of living with ET.
In any case, this new study by Teodoro, et al. may help reframe the professional debate about whether ET and other neurological conditions is biologically connected to FCD, or simply an understandable “hijacking” of a person’s attention.
iTeodoro T, Edwards MJ, Isaacs JD. A unifying theory for cognitive abnormalities in functional neurological disorders, fibromyalgia and chronic fatigue syndrome: systematic review. J Neurol Neurosurg Psychiatry. Published online first: 07 May 2018. doi:10.1136/jnnp-2017-317823