Brain Evaluation

WHAT DO WE KNOW ABOUT COGNTIVE RESERVE?

The term cognitive reserve has been used to identify higher levels of brain function or ability that is present.  This ability may not always appear to be outwardly present and instead may be used to compensate for deficits or problems.  In other words a person may appear average when they really have above average ability but that above average ability is being used for compensation. So they are not diagnosed as having a deficit because their performance is average when they really have higher ability and average performance represents their compensation and actually the presence of a problem.   Put another way, cognitive reserve suggests that average scoring does actually reflect a problem given that higher cognitive abilities are employed to compensate for deficits areas. Research suggests that if someone has attained a higher level of education such as college study or a college degree this means that they have a higher intellectual ability.   This also applies to the occupation one has and overall life achievement.   So factors of education, occupation and life achievement have been shown to provide a neuroprotective mechanism for people (Neurology Today September 6,
2012). Studies have shown that tests reveal that some people despite having up to 25 percent of their brain showing plaques and tangles sufficient to meet the criteria for Alzheimer’s disease do not show outward signs of cognitive or intellectual decline when compared to other individuals who have the same test results (of plaques and tangles) who outwardly appear quite demented.  The difference is that the first group of individuals has the protection of higher levels of cognitive reserve.  This poses the question; how does education help the brain?  Is it by stimulating dendritic branching (of the neurons establishing more brain connections) enabling the brain to sustain more atrophy before displaying deficits or are there more neurons to begin with and therefore a loss of neurons has less impact upon the brain?.  Education is clearly being seen as a neuroprotection against memory loss and other symptoms based upon a study of 872 brains.  This also begs the question as to whether higher education means more affluence, a better lifestyle, better health care and better access to things that stimulate the brain. Then there is the role of the presynaptic proteins.  Recent research found that the action of the presynaptic process is a key issue.  It is this process that releases and repackages brain neurotransmitters which is related to better cognitive function and a lower risk of dementia.  In the same manner, more loss of neurons as a reliable marker of dementia was associated with lower levels of certain presynaptic proteins.  The general idea is that there are more processes to investigate for medication intervention but also for cognitive or brain rehabilitation therapy.

WHAT DOES THIS MEAN?IT COULD MEAN
THAT THE USE OF COGNITIVE TRAINING OR BRAIN TRAINING MAY IN FACT BE RLEATED TO
BETTER COGNITIVE RESERVE AND OUTCOMES FOR DEMENTIA. THIS WOULD SUGGEST THE NEED
TO DO BRAIN TRAINING EARLY IN ONE’S LIFE IN THE 40’S AND 50’S AND TO REMAIN
ACTIVE.

Researches are beginning to look at the synapse (where the neurons talk to each other and exchange information) as a primary site for dementia as opposed to the amount of amyloid and amyloid burden.
The idea being that research is looking more at the overall functioning of the brain or brain functioning on a cellular level to understand dementia. 

 

HELPING TO MINIMIZE THE EFFECTS OF COPD AND ASTHMA WITH TREATMENT OF ANXIETY AND DEPRESSION

A large scale recent study pointed to the need to address the co-morbid effects of anxiety and depression impacting the immediate and long term effects of these diseases of Chronic Obstructive Pulmonary Disease and asthma. (Pommer et.al., Managing co-morbid depression and anxiety in primary care patients with asthma and/or chronic obstructive pulmonary disease: study protocol for a randomized controlled trial,Trials, 2012, January 11:13;6)

NO COGNITIVE SIGNS OF INJURY BUT PRO SOCCER PLAYERS SHOWING WHITE MATTER DAMAGE CONSISTENT WITH TRAUMATIC BRAIN INJURY

A recent study revealed neuroimaging showing white matter changes in the brain in players who have a history of repeated concussion and blows to the head.  Areas of the brain affected can impact the
memory and executive reasoning areas of the brain.  Impact to more posterior brain areas can
affect the processing of visual information. The study published on November 14, 2012 in the Journal of the American Medical Association reported increased radial diffusivity in soccer players in the right orbitofrontal white matter, the genu and anterior portions of the corpus callosum, association fibers
involving bilateral inferior fronto-occipital fasciculus, bilateral optic radiation and bilateral anterior cingulum, right anterior, right superior and bilateral posterior corona radiata, right anterior limb of the internal capsule, right external capsule and right superior frontal gyrus.  This type of injury is likely the result of passing the ball using only the head and suggests possible demyelination.  This is the first study showing problems in players displaying no outward symptoms. The changes in white matter diffusibility are similar to that seen in the professional football and hockey players who have symptoms of concussion.

WHAT DO WE KNOW? COGNTIVE OR BRAIN TRAINNG MAY BE MORE IMPORTANT THAN YOU THINK

It is coming to light that cognitive or brain training is needed for everyone to ensure graceful aging.  Perhaps if everyone engaged in some form of cognitive training in their 40’s and 50’s or 60’s we would not be seeing so much dementia.  If those individuals diagnosed with high blood pressure or any type of heart disease were more aggressive with their lifestyle and integrated brain training into their
routine then their outcome for aging could possibly improve tenfold and they would not be as vulnerable to dementia.  Brain training can also be used to combat delirium or the after effects of delirium following surgery in the aged person so their life does not dramatically decline following hip surgery or cardiovascular surgery.  As I mentioned earlier in this blog, research on cognitive decline is telling us that cognitive reserve; meaning people who are more active with their brain, furthered their education, and/or have higher abilities provides a protective mechanism for aging effects.  This tells us that cognitive training may be useful for everyone to protect themselves against dementia as we are aging longer.

NFL FOOTBALL PLAYERS, RISK OF ELEVATED MORTALITY ASOCIATED WITH NEURODEGENERATIVE DISEASE

Neurology Today October 4 2012.  Football players were found to have a four times greater likelihood of having a neurological disorder of Alzheimer’s or ALS as a contributing factor to their death. Of the 17 deaths, 14 were speed position players.  The brains of professional football players who played in the NFL from 1959 to 1988 were studied. Death related to neurological causes was three times higher than the general US population.  Death was four times higher for the diagnosis of two major neurogenerative illnesses; Alzheimer’s disease and ALS (Amyotrophic Lateral Sclerosis).  Mortality was higher in those who played in speed positions requiring the players to accelerate prior to being hit or tackled compared to non-speed positions.  Numbers are small in the study although the results are striking and consistent with prior research showing the risk of neurological disease among football players and individuals who experience head trauma or repeated concessions.  CTE (Chronic
Traumatic Encephalopathy) was identified as a pathologically distinct neurodegenerative condition affecting those who have had multiple concussions.  Those individuals diagnosed with CTE exhibit symptoms of executive reasoning deficits, changes in personality as well as memory and cognitive function. 

CENTER FOR DISEASE CONTROL DOCUMENTS POOR LEVELS OF BASIC PREVENTATIVE SERVICES TO PREVENT STROKES IN THE US.

A report authored by the CDC in June of 2012 found that only 44 percent of adults diagnosed with high blood pressure and only 32 percent diagnosed with high LDL cholesterol had it under control.  Fewer than one in 13 tobacco users who visited a doctor were prescribed medications to help them quit
smoking.  Among patients with heart disease only 47 percent were prescribed the simple and inexpensive treatment of aspirin to be taken on a daily basis.The report indicated that increasing
the use of these preventative strategies of medication and ceasing bad habits such as smoking has the potential to lead to significant declines in the illness, death and instability of individuals living in the US.  Neurologists believe that strokes would certain decline if there was better control of these cardiovascular risk factors noted in a Neurology Today report (September 6, 2012). There are seven guidelines proposed by the American Heart Association for maintaining heart health:  Not smoking, maintaining normal weight, exercising, eating a healthy diet and controlling cholesterol, blood pressure and blood glucose.  Almost 25 percent of the 800,000 strokes per year in the US are recurrent strokes where preventative efforts could be an important factor.

WHITE MATTER INJURY IS MARKER FOR AGE RELATED COGNTITVE DECLINE

According to Neurology Today (August 16, 2012) white matter damage or injury is no longer seen as typical aging.  White matter refers to damage to the brain affecting our thinking or cortical brain areas.  White matter is seen as a preclinical marker for cognitive decline and Alzheimer’s disease. 
Microstructural white matter changes are identifying individuals who show no cognitive difficulties to be at risk for mild cognitive decline and dementia.  Suggested is that the disease begins early and ten years before cognitive problems and poor memory are actually apparent (thus the term preclinical) in daily life.  The take away point is that lesions (or impact to brain structures) involving as little as three percent of the white matter produces impairment in working memory in demented individuals.  The diagnosis of vascular dementia is given when there is a clear relationship in the severity and pattern of cognitive impairment and the presence of diffuse subcortical cerebrovascular disease pathology (brain areas affected by the loss of adequate blood flow).   The idea is that age related cognitive decline, a term seen on the MRI test results, is not normal aging and instead a marker of dementia and that further, more often, dementia is a mixed picture of neurodegenerative and vascular (heart related) pathologies.

IN LATE LIFE, LOW BLOOD PRESSURE CAN BE A MARKER FOR DEMENTIA RISK

Blood pressure or arterial blood pressure is the pressure exerted by circulating blood upon the walls of the blood vessels and is one of the principal vita signs of health.  For each heart beat blood pressure varies between a maximum (systolic) and minimum (diastolic) pressure.   We tend to pay more attention to the maximum rather than the minimum blood pressure.  However a sustained lower diastolic blood pressure may actually be a measure of vascular health as we age.  When diastolic blood pressure drops, it may be related to a progression of global and subcortical brain atrophy seen among
middle aged patients with arterial disease. The thought is that vascular disease makes patients more vulnerable to lower diastolic blood pressure and subsequent neurodegeneration.  Subcortical brain volume was actually reduced by 0.8 percent where patients had low diastolic blood pressure.   When individuals who had never been diagnosed with hypertension, had a midlife diagnosis of hypertension, this was associated with increased risk of damage to the brain (cortical and subcortical infarctions) in late life. Midlife hypertension was associated with a 14 percent increase in white matter hyperintensity volume seen on MRI studies.   In individuals with a history of hypertension reduced blood pressure was associated with an increase in the neurodegeneration biomarker CSF phosphate-tau as well as deterioration of episodic memory (memory for events).  Another speculation is that
high midlife blood pressure could increase the risk of cerebral hypofusion resulting in changes in the brain making the brain more vulnerable (Neurology Today, September 20, 2012).

 

DELIRIUM FOLLOWING CARDIAC SURGERY MAY NOT BE A TEMPORARY STATE

Delirium is defined when a person is out of their mind to put it simply, is not oriented, does not know where they are and highly confused.  Delirium which is recognized as a complication often seen resulting from any surgery may actually be the beginning of cognitive decline requiring aggressive
intervention and treatment at the time or shortly after it occurs.  A recent study found that after undergoing cardiac surgery, 46 percent of 225 cardiac surgery patients who were diagnosed
with post-operative delirium were less likely to return to their baseline level of cognitive functioning.  This means that once they had this episode of being incoherent, they never came back to who they were. These patients may need to be more closely monitored after surgery and hospital discharge.  Therapy following discharge may need to be tailored to address cognitive decline and provide cognitive rehabilitation or brain training.  In the hospital setting there are some helpful interventions that can be employed.  Not waking patients up in the middle of the night for tests or procedures to ensure good sleep.  To make sure that patients have their eye glasses or hearing aids on following surgery to prevent disorientation.  Have a clock in their room with the date and news on the television to remind them of what is going on in the world.  Another thought is that delirium developing post-surgery may be the unmasking of cognitive decline and greater vulnerability that is already present in the individual.  Neurology Today, August 16, 2012.

THE IMPACT OF HIGH BLOOD PRESSURE UPON THE BRAIN IN MIDDLE AGE

According to a recent study published in Lancet Neurology in December of 2012, using diffusion tensor
imaging there was greater evidence of white matter damage (especially in the anterior corpus callosum, the inferior fronto-occipital fasciculi and fibers projecting from the thalamus to the superior frontal gyrus) found in individuals as young as forty years old when diagnosed with high blood
pressure.  An association was found between systolic blood pressure and white matter damage in 579 people with a mean age of 39.2 years that are part of a long term heart study.  Elevated blood pressure correlated with greater evidence of white matter damage in areas of the brain that impact
executive reasoning processes.

THE MATURATION OF MYELINATION AND IMPACT UPON THOUGHT AND BEHAVIOR

A
study published in the Proceedings of the National Academy of Sciences in the September 24^th online edition compared recent findings on the largest sample of chimpanzee neural development to human brain tissue.  There was a comparison of brain tissue from young, middle aged and older brains for chimpanzees and for humans. Findings suggest that humans are more delayed in myelination than the chimpanzees. Myelination is important in the brain; the more myelination the better able the brain is to communicate effectively and meaningfully amongst the various systems involved in cognition and thought. The point of this article is that there is a slowing down of myelination for humans during young adulthood and adolescence and that this difference may make humans particularly vulnerable to some psychiatric diseases such as schizophrenia.  Schizophrenia is being linked to abnormal
myelination of axons and strikes in late adolescence and early adulthood. Based upon the comparison of the chimpanzee and human brains, authors reported a shift in the timing of cortical maturation that is specific to humans which occurs during adolescence.  There is a push back of the timing of the myelination; the slowing down of myelination is thought to provide humans with more opportunity for the impact of their environment, social interactions and cultural experiences that impact the brain
which still has greater plasticity at that point in time.  Abnormal white matter connections can affect
psychosocial organization, resulting in more fragmented thought processes.   As the brain matures and tracks are myelinated, the brain is able to improve in selection attention, decision making,inhibitory control and working memory which coincides with the expectations of society at that developmental time.