A report from my mother after her visit to a physician made me change the way I assess older patients who experience episodes of forgetfulness. As a family nurse practitioner, I knew the physician’s diagnostic approach was similar to mine, followed consensus guidelines, and met the standard of care. However, I thought the diagnosis missed the mark and left my mother vulnerable and our family frustrated. The diagnosis also made me wonder, “How many cases like hers have I missed?”
For several years, Mom, age 78, had been having difficulty recalling names and dates, which she attributed to aging. She compensated well by keeping a calendar with birthdays and appointments and writing reminder notes. She felt that these were common age-appropriate coping behaviors.
Mom and her primary physician met periodically to monitor her hypothyroidism. She enjoyed good health, walked about four miles every day, maintained her BMI at about 25, and did not smoke or drink alcohol. She usually slept six to eight hours a night. Married and the mother of four children, she was a retired kindergarten teacher.
Recently, Mom’s forgetfulness and aberrations in judgment had begun to interfere with her daily activities. She misplaced items like keys several times daily but usually found them within a few hours. After rushing to a birthday party, she forgot to turn off the ignition in her car when she arrived, leaving the motor running for two hours. She left food in the oven twice while napping; fortunately, my father noticed the smoke. Mom knew her forgetfulness was an issue and was embarrassed by her behavior.
The sentinel event occurred when a stranger on the phone talked Mom into giving him her bank account information. She initially resisted but conceded to his demands when he became aggressive. After the call, she realized she had made a mistake and confided in Dad. Together, they went to the bank to change the account number.
Mom agreed to discuss these issues with her physician. She went by herself to see him, but at our family’s urging she had compiled a list of examples of her forgetfulness. After explaining to the physician that she was there at her family’s request, Mom gave him the list. She reported later that the physician interviewed her and performed an evaluation that included the Mini-Mental State Examination (MMSE).
Mom returned home and happily told the family that she had “passed” the interview and the MMSE and that she did not have Alzheimer’s disease. Her physician had told her that she was within the normal range of forgetfulness for her age. Mom said he suggested she was trying to do too many things at a time and should slow down. He suggested that she set a timer on the stove when cooking as a reminder to watch the food.
Mom’s report of her appointment with her physician motivated me to learn more about diagnosing dementia. I was reminded that dementia is an acquired syndrome marked by a decline in memory and at least one other area of cognition, such as visual-spatial, language, or executive function (the ability to organize thoughts and make decisions). Alzheimer’s disease is the most common form of dementia, accounting for 50% to 60% of all dementing illnesses. Vascular dementias account for about 15% to 20% and often occur with Alzheimer’s disease.
Many primary care providers commonly use the MMSE to screen for dementia. According to the US Preventive Services Task Force report of 2006, the MMSE is the best-studied instrument for cognitive impairment screening, with a sensitivity of 87% and a specificity of 82%. Its accuracy varies with the patient’s age, education, and ethnicity and is most accurate for white people with at least a high school education.
I also learned about the MMSE’s limitations and the value of additional testing, including executive function testing when the patient evaluation is inconsistent with the presenting complaint. The MMSE assesses cortical changes, but Mom’s predominant symptoms aligned more with decision making and distractibility. Executive function testing targets the subcortical dementias, such as vascular dementias, and the motor deficits of Parkinson disease, Huntington disease, and normal-pressure hydrocephalus. Some authors estimate that as many as 40% of dementias may go undiagnosed with a work-up relying primarily on the MMSE.
At my request, Mom was referred to a neurologist, who ordered various laboratory tests and a brain MRI, which revealed no abnormalities. The results of additional testing, however, were consistent with executive dysfunction.
Because there are gaps in our knowledge about screening for and treating dementias, there is no recommended therapy for subcortical dementias. The neurologist had noted some improvement in executive function by treating distractibility with bupropion, so Mom was started on a trial course of that drug. Unfortunately, the directions for escalating the dose confused her. Eventually, she had to be taken to the emergency department for acute disorientation, confusion, slurred speech, and weakness related to excessive dosing.