Identifying Mild Neurocognitive Disorder in Older Patients

May 13, 2016

Depression can be accompanied by cognitive symptoms, but the nature of the relationship between these symptom categories is multifaceted.

Is it possible to delay or prevent the onset of cognitive impairment or the progression from mild impairment to major neurocognitive disorder? That is the question addressed at APA 2016 in a course titled “Identifying and Helping Our Older Adults with Mild Neurocognitive Disorder.”

The course was developed in order to help clinicians understand the significance of mild neurocognitive disorder (MiND), a newly defined syndrome in DSM-5. The multidisciplinary team of lecturers addresses the disorder definition of MiND, its causes and natural history, assessment using neuropsychological and advanced imaging techniques, and state-of-the-art evidence-based interventions.

MiND and depression
Before current biomarker studies validated the existence of this clinical syndrome, mild cognitive symptoms were often attributed to depression or anxiety. Mood disorders can indeed be accompanied by cognitive symptoms, but the nature of the relationship between these symptom categories is multifaceted.

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Changes in cognition
Mild age-associated changes in cognition reflect aging of the brain, much as changes in glomerular filtration and reduced aerobic capacity can accompany aging of the kidney and heart. The aging brain does not, as once believed, lose vast amounts of neurons over time; however, changes in synaptic structure, diminished activity of key neurotransmitters, altered integrity of white matter, and global loss of volume are typical findings in older brains.

The essence of the DSM-5 definition of MiND is a limited but significant functional impairment associated with an acquired decline in one of 6 cognitive domains.

The functional manifestation of these changes is reflected in the different norms that apply to neuropsychological test performance of older subjects. The majority of older adults note subtle changes in memory or other cognitive functions, and fear of memory loss is one of the most prevalent of serious health concerns in this population. Fortunately, these changes are simply a minor nuisance for many.

“Subjective cognitive impairment,” a syndrome that has begun to attract the attention of researchers and clinicians, describes individuals-usually older adults-with more compromised cognitive functioning that still falls below the sensitivity of standardized screening tests. Subjective cognitive impairment is not yet a DSM-5 diagnosis, but it is can be a precursor to MiND. Concerns about memory may lead an older adult to seek evaluation. Others may express concern about language, executive function, or other cognitive areas.

DSM-5 and MiND
The essence of the DSM-5 definition of MiND is a limited but significant functional impairment associated with an acquired decline in one of 6 cognitive domains: attention, memory, language, visuospatial, executive function, or social cognition. The impairment is enough to require an individual to engage in compensatory behaviors to deal with a cognitive decline that is significant but not so severe as to cause loss of independence. New dependence on cueing, reminders, lists, assistive technology such as GPS, or the help of others can signify the presence of MiND despite relatively limited functional compromise.

Mounting evidence supports the notion that MiND can represent the prodromal stage of major neurocognitive disorder, whether associated with Alzheimer disease or another etiology. Cognitive impairment that does not meet the criteria for the major disorder has been linked with biomarker changes, including hippocampal and global brain volume loss, changes in regional glucose metabolism, amyloid deposition, and deposition of amyloid plaques. Although a small percentage of people with MiND function more normally at later reexamination, a significant percentage will progress to MiND over time.

DANCERS approach
A growing and necessary focus in the treatment of neurocognitive disorders is prevention. Thorough assessment of milder cognitive changes in older adults facilitates interventions that may in some cases delay progression. Identifiable medical causes of cognitive symptoms such as uncontrolled diabetes with hyperglycemia or hypoglycemia can sometimes be identified and addressed.

Modification of physical activity, diet, and cognitive stimulation have each been proposed to improve cognitive functioning and delay decline, although the evidence for each of these is not unmixed. Social engagement, relaxation, and adequate sleep each appear to play a role in maintaining cognitive health.

These evidence-based categories of intervention are joined in the mnemonic DANCERS (Table), and listed with potential areas for clinical inquiry and recommendations. As our population continues to age, clinicians will inevitably encounter more requests for advice and guidance in managing milder age-associated cognitive changes. “Identifying and Helping Our Older Adults with Mild Neurocognitive Disorder” points the way toward applying current knowledge about assessment and early intervention.

The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet score has 15 dietary components including 10 brain healthy food groups (green leafy vegetables, other vegetables, nuts, berries, beans, whole grains, fish, poultry, olive oil, and wine) and 5 unhealthy food groups (red meats, butter and stick margarine, cheese, pastries and sweets, and fried/fast food).

Further reading
Tangney CC, Wang Y, Sacks FM, et al. MIND diet associated with reduced incidence of Alzheimer's disease. Alzheimers Dement. 2015;11:1007-1014.http://www.alzheimersanddementia.com/article/S1552-5260%2815%2900017-5/abstract. Accessed April 29, 2016.

D'Anna A. New Diet May Lessen Risk of Dementia Diagnosis. Annals of Long-Term Care. June 1, 2015. http://www.annalsoflongtermcare.com/article/new-diet-may-lessen-risk-dementia-diagnosis. Accessed April 29, 2016.

Disclosures:

Dr Ellison is the Swank Foundation Endowed Chair in Memory Care and Geriatrics at Christiana Care in Wilmington, Delaware.