Everyone starts to notice some difficulty with their memory as they have the luxury of living longer. We all recognize that the young are blessed with “quick” minds and tend to be very facile at learning things such as computer technology as well as foreign languages. Naturally, as we age, they make up for much of this with experience, wisdom and maturity. Older people also have bigger “data banks” as we retain memories from our youth while young people don’t have anywhere near as much to recall so the efficiency of recall is probably enhanced. However, when a neurologist looks at the brain scan of a 70 year old person, it is often a bit different than that of a 30 year old person. Just as the skin and bone age, the brain tends to show some shrinkage, termed “atrophy”, as we grow older. It is important to keep things in perspective as a 29 or 30 year old athlete might be termed “an aging veteran” which seems absurd until we realize that their legs are starting to show the effects of aging at what appears to still be “youth”. Realistically, we are probably most nimble in our teens and 20’s before aging starts to set in.
Forgetfulness is not necessarily unexpected or something we can’t cope with by keeping better track of things either with our hand-held devices or writing things down. However, for certain people, generally in their 70’s and beyond, we start to notice an impact on the quality of life. The finances might not be handled as effectively and driving might become an increasing problem in terms of safe driving and not getting lost while driving. The family might have to step in to protect the financial security of the individual and the loved ones as well as to protect society from someone who should no longer be driving. There is a tendency for relative preservation of mental function. Generally, the short-term is affected but the person might still be “sharp as a tack” for longer term recall as well as with crossword puzzles and other hobbies. There can be personality change and the person might become more socially withdrawn as part of the cognitive impairment as well as perhaps to prevent others from picking up on their deficiencies.
We use various tools to address cognitive impairment as it evolves from an increasingly used term “mild cognitive impairment” (MCI) to actual dementia where there is functional limitation on a cognitive basis that needs to be addressed. The term dementia is a generic term for clinically significant cognitive impairment which tends to be progressive and irreversible. Naturally, the biggest concern for patients and their families is Alzheimer’s disease which now affects millions of patients in the United States and is the most common cause of dementia in older individuals. However, there are a number of more treatable forms of dementia such as that seen with severe thyroid hormone deficiency, that seen with vitamin B12 deficiency, that seen with normal pressure hydrocephalus, that resulting from resectable brain tumor or chronic subdural hematoma, or cognitive impairment related to a treatable medical illness or to a medication that can be discontinued. There can still be cases of dementia related to syphilis affecting the central nervous system and it is not uncommon in susceptible individuals who suffer advanced complications of HIV infection. Neurological patients with stroke, multiple sclerosis and certain movement disorders such as Parkinson’s disease often have some degree of cognitive impairment which could constitute dementia in some. Certain epileptic conditions can lead to a dementing type process that is responsive to anticonvulsant therapy.
The evaluation includes cognitive testing which often starts with a mini-mental state exam in the office as a screening tool. Some patients, especially those with atypical presentations, might benefit from formal neuropsychological assessment. A brain scan, either MRI or CT brain scan is routinely performed along with blood work to check for deficiency conditions or metabolic disturbance. An EEG might be useful for patients with fluctuations in cognitive function that might suggest a seizure disorder. Some patients may need confirmation with special blood tests such an apolipoprotein E4 allele study. The cerebrospinal fluid exam can be useful in helping to support the diagnosis of Alzheimer’s. As we now all recognize, this disorder has become an increasing burden for society as it is by far the leading cause of dementia in the elderly, with a significant impact on quality of life, and can afflict even relatively young individuals in certain instances. It can have a severe impact on the families who care for such patients. The cerebral positron emission tomography (PET) scan can now not only show a characteristic brain glucose metabolic pattern in Alzheimer’s disease but there is also now in vivo imaging available of the beta-amyloid plaques associated with Alzheimer’s disease.
Treatment is geared to maintaining functional independence and quality of life as effectively as possible. Mental stimulation and physical activity, that the patient is receptive to, can be helpful to some degree. Cholinesterase agents provide some marginal benefit and may help to slow down the progression of the disease. These include donepezil (Aricept) as well as Exelon which is available as a patch. The agent memantine (Namenda) might also provide some benefit in certain individuals. The food supplement Axona has also been approved by the FDA in an effort to provide some cognitive benefit in certain individuals.
Neurological evaluation and monitoring of patients with cognitive deficit helps guide the family in management of the patient and addresses expectations and limitations. Working together with the family, the particular patient’s clinical course can be tailored, by the neurologist, in terms of level of support necessary as well as the potential need for sedating agents to be used to protect against aggressive behavior. Drs. Roger Kelley and Angela Traylor have an active practice in the evaluation and management of cognitive impairment including dementia. Their colleagues also provide such expertise and include Drs. John Freiberg, Greg Redmann, Morteza Shamsnia, and Patricia Colon.
Tulane University, New Orleans, LA 70118 504-865-5000 firstname.lastname@example.org