The 3 Steps to Early Diagnosis of Alzheimer's in Primary Care

June 3, 2007
Daniel M. Keller, PhD

Internal Medicine World Report, May 2006, Volume 0, Issue 0

From the American Association for Geriatric Psychiatry

SAN JUAN, Puerto Rico—Currently available antidementia drugs have been shown to benefit patients with Alzheimer’s disease (AD), especially those with mild-to-moderate disease. At the Annual Meeting of the American Association for Geriatric Psychiatry, George Grossberg, MD, director of geriatric psychiatry, St. Louis University School of Medicine, Missouri, and Elaine Peskind, MD, associate director, Alzheimer’s Disease Research Center, University of Washington, Seattle, discussed how primary care physicians can make an early diagnosis of AD, despite the inherent difficulties of this diagnosis.

Dr Grossberg said AD can be diagnosed 90% of the time with a general medical and psychiatric evaluation and a detailed history from the patient and a reliable informant, which can usually be accomplished in the primary care setting. But primary care physicians may be reluctant to evaluate patients for AD because of time constraints, unfamiliarity with appropriate reimbursement codes, an overabundance of tests, the complicated differential diagnosis (ie, vascular, frontotemporal, or Lewy body dementia), and the challenge of comorbid conditions (ie, differentiating dementia, delirium, or depression).

A 3-Visit Plan

To overcome these obstacles, he suggested scheduling high-risk patients for the end of the day to permit adequate time with them, dividing the evaluation into 3 office visits, and knowing reimbursement codes for the extra time required, noting that a 15-minute office visit is insufficient for a full evaluation.

A proper evaluation includes a caregiver interview, sleep history, activities of daily living inventory, and possibly screening for depression. Screening involves quantitative, objective measurements that do not depend on qualitative responses. Assessing dementia includes general health, neurologic, laboratory, and brain structure screens.

The first visit may consist of history taking that explores memory impairment in normal activities, executive impairment (eg, performing complex tasks, problem solving, or driving), alcohol and prescription or over-the-counter drug use, and focal motor or sensory neurologic symptoms. An interview with a close family member/caregiver is helpful, and for cooperative patients, so are a Mini Mental State Exam (MMSE) and a clock-drawing test. Also explore family needs and caregiver stress.

During the second visit, perform laboratory testing (eg, complete blood cell count; HIV testing; measurements of electrolytes, B12, folate, homocysteine), order neuroimaging studies, and consider neuropsychological testing.

In the third visit, review laboratory findings and other test results, discuss treatment options and follow-up plans for the patient, and revisit family and caregiver needs.

Once a patient is receiving a cholinesterase inhibitor (ChEI), Dr Peskind performs an MMSE once a year and documents cognitive, functional, and behavioral end points. She asks the caregivers if the patient is stable or is declining quickly. Also consider factors that are not apparent on an objective test, such as the patient’s behavior or ability to interact.

Treatment may be unsuccessful for various reasons, including unrealistic expectations, too-low dosages, noncompliance, inadequate treatment length, or concomitant use of anticholinergic medications (eg, urinary incontinence drugs, tricyclic antidepressants, diphenhydramine) that interfere with ChEIs. If a patient continues to progress or has intolerable side effects, Dr Grossberg recommends switching to another ChEI, titrating it, and then waiting to see what happens over time.

Early diagnosis and treatment of AD provide the best chance of prolonging patients’ function. It may also delay nursing home placement.

KEY POINTS

Schedule high-risk patients for the end of the day.

Divide the evaluation into 3 office visits.

The 3 visits break the process into manageable but accurate steps that facilitate early diagnosis.

Know the appropriate reimbursement codes.