Causes of Cognitive Impairment
Cognitive impairment can arise from virtually any poorly controlled chronic disease of the brain or the body’s organs, including hypertension, high cholesterol, heart disease, stroke, peripheral vascular disease, hypothyroidism, diabetes, chronic obstructive lung disease, kidney disease, infections, severe pain syndromes, obesity, sleep apnea, depression, anxiety, bipolar disorder, obsessive compulsive disorder, attention deficit disorder, multiple sclerosis, epilepsy, and alcohol, sedative, opiate or other chemical dependency. Single or repeated head injuries can impair cognition. Certain medications that get into the brain can impair cognition, such as tranquilizers, anticonvulsants, antipsychotics, older antidepressants, pain medications, and older bladder incontinence medications. Most of these conditions are treatable, particularly when cognitive impairment is detected early through annual monitoring of cognition after age 50 years old.
The degenerative brain disorders account for less than 50% of all people with cognitive impairment in primary care medical settings. These include Alzheimer’s Disease (AD), Parkinson’s Disease, Lewy Body Disease, Frontal Temporal Lobe Disease, and prion disease.
Recent studies show that although Alzheimer’s disease is not curable, it can be effectively treated to largely preserve independence and eliminate institutionalization in most individuals. In 2008, Atri Ali and colleagues at the Massachusetts General Hospital Memory Disorders Unit reported in the journal, AD and Associated Disorders, one of the most well analyzed longitudinal studies of Alzheimer’s disease. Patients treated for up to four years with the combination of Namenda and a cholinesterase inhibitor (Aricept, Exelon or Razadyne) delayed the functional rates of decline during the MCI stage by 33%, and during the dementia stage by 50-60%. This means that over the 14 year course of the MCI and dementia stages of AD, early detection, accurate diagnosis and combined therapy with Namenda and a cholinesterase inhibitor can delay the functional decline in AD patients by an average of 5-6 years. Since AD individuals spend an average of 4 years in institutions, the proper current approach can largely eliminate institutionalization.
Cognitive Severity Stages (Normal Aging - Dementia)
The four cognitive severity stages spanning normal aging to dementia are:
- No Cognitive Impairment (NCI) – individuals perceive no decline in cognition and no decline in complex skills that rely on their cognitive abilities. The NCI stage characterizes normal aging individuals, plus those with a cognitively impairing disorder that is not severe enough to produce any change in these abilities. The average duration of NCI is 30 years.
- Subjective Cognitive Impairment (SCI) – a perceived or subjective decline in cognitive or functional abilities that does not keep an individual from performing any of their usual or most complex activities. Individuals are aware that there has been a decline in some ability but that they can still compensate to perform it. The SCI stage characterizes normal aging individuals as well as those who are progressively becoming more impaired due to a cognitive disorder. In Alzheimer’s disease, the SCI stage lasts 15 years.
- Mild Cognitive Impairment (MCI) – a decline in cognitive abilities such as language, memory reasoning, judgment, or perception that is not due to normal aging. Individuals in the MCI stage of severity can independently drive, shop, cook, pay bills, manage finances, do household chores and other well-learned skills that do not place significant demands upon learning new information. The MCI stage is not seen in normal aging individuals, and is due to one or more cognitive disorders. In Alzheimer’s disease, the MCI stage lasts an average of 7 years.
- Dementia – the level of severity after the MCI stage in most cognitively impairing disorders. Individuals in the dementia stage have declined in ability to perform instrumental activities of daily living, which include well learned skills such as cooking, shopping for groceries, driving to familiar locations, paying bills, doing housework or home repairs, performing well learned hobbies or pastimes. The dementia stage progresses to affect even more well learned skills, called basic activities of daily living, including bathing, dressing, operating a toilet, planning to urinate or defecate so that they get to the toilet on time. Dementia finally progresses to affect walking speech, swallowing and control of the trunk, neck and face. The dementia stage is not seen in normal aging individuals and is due to one or more cognitive disorders. In Alzheimer’s Disease, the dementia stage lasts an average of 7 years.
Mild Cognitive Impairment (MCI)
MCI is also identified as the first clinical stage of Alzheimer’s disease (AD). The subtype of MCI associated with AD is called amnestic MCI and affects an individual’s memory. Approximately 80% of people with amnestic MCI develop AD within 6 years. According to the Mayo Clinic, 15-20% of MCI patients progress to dementia each year. In comparison, the progression rate for the general population is 1-2%. Since MCI is the first symptomatic stage of AD, accurately detecting MCI enables medical professionals to then take the steps necessary to determine if a patient has early stage AD and might benefit from timely intervention.
Symptoms of Mild Cognitive Impairment (MCI)
Your brain changes as you grow older just like the rest of your body. Many people notice gradually increasing forgetfulness as they age. It may take longer to think of a word or to recall a person's name.
But consistent or increasing concern about your mental performance may suggest MCI. Cognitive issues may go beyond what's expected and indicate possible MCI if you experience any or all of the following:
- You forget things more often.
- You forget important events such as appointments or social engagements.
- You lose your train of thought or the thread of conversations, books or movies.
- You feel increasingly overwhelmed by making decisions, planning steps to accomplish a task or interpreting instructions.
- You start to have trouble finding your way around familiar environments.
- You become more impulsive or show increasingly poor judgment.
- Your family and friends notice any of these changes.
If you have MCI, you may also experience:
- Irritability and aggression
Individuals in the dementia stage (of the cognitive severity stages listed above) have declined in ability to perform instrumental activities of daily living, which include well learned skills such as cooking, shopping for groceries, driving to familiar locations, paying bills, doing housework or home repairs, performing well learned hobbies or pastimes. The dementia stage progresses to affect even more well learned skills, called basic activities of daily living, including bathing, dressing, operating a toilet, planning to urinate or defecate so that they get to the toilet on time. Dementia finally progresses to affect walking speech, swallowing and control of the trunk, neck and face. The dementia stage is not seen in normal aging individuals and is due to one or more cognitive disorders. In Alzheimer’s Disease, the dementia stage lasts an average of 7 years.
Examples of cognitive impairment often seen during the dementia stage are:
- Rapid forgetting of recent instructions, conversations, or events
- Difficulty recognizing or naming common objects, familiar persons, or places
- Difficulty communicating in one's usual capacity
- Difficulty making decisions or judgments such as the proper clothing to wear
- Difficulty organizing, planning and executing tasks such as packing or planning a vacation
- Difficulty operating familiar instruments such as a remote control, telephone, or computer
Alzheimer's Disease (AD)
AD is a disease that predominantly afflicts those over the age of 50, although most do not have symptoms that are severe enough to cause concern until after the age of 65. In 1900, the average life expectancy was 47 years, so AD occurred rarely. Since then, life expectancy in the United States has increased to 77.9 years driving up the incidence of Alzheimer's disease. AD is now a major economic health care problem and is the most common neurodegenerative disease of the aging.
Key Numbers About AD (Based on 2010 data)
- 5.3 million people have Alzheimer's disease in the United States
- 172 billion dollars in annual cost in the United States
- 10.9 million unpaid caregivers in the United States
- 6th leading cause of death in the United States
- 4th leading cause of death in Orange County
Methods of prevention and treatment have been identified in recent research trials that might significantly delay both the onset of symptoms and AD progression. Early assessment helps reassure healthy aging persons, or detect a problem in its earliest and most treatable stage. Benefits of early detection include forestalling progression of cognitive disorders to maintain quality of life, reduce or eliminate institutionalization, and reduce related health care costs.