New Alzheimer’s guideline outlines diagnostic process for specialists, PCPs

Key takeaways:

• A workgroup convened by the Alzheimer’s Association established a three-step formulation for diagnosing Alzheimer’s disease or related disorders.
• The recommendations are applicable to specialty and primary care.

A new guideline published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association summarizes best practices for specialists and primary care providers on how to evaluate patients with suspected Alzheimer’s disease or related disorders.

The guideline was developed by a group of experts convened under the Alzheimer’s Association. It is the first comprehensive guideline in the United States that can be applied across practice settings, from primary to specialty care, according to a press release from the Alzheimer’s Association.

“With this guideline, we expand the scope of prior guidelines by providing recommendations for practicing clinicians on the process from start to finish,” author Brad Dickerson, MD, director of the Massachusetts General Hospital Frontotemporal Disorders Unit and professor of neurology at Harvard Medical School, said in the release.

Dickerson and colleagues established a framework for patient-centered evaluation based on a three-step diagnostic formulation:

• cognitive functional status (the level of impairment);
• cognitive-behavioral syndrome (the patient’s symptoms such as language difficulty and memory loss); and
• likely diseases or conditions causing the symptoms.

With this formulation, the authors developed 19 practical recommendations that begin with understanding the patients’ goals of care, followed by steps for obtaining information about their symptoms, tailoring the use of diagnostic tests and disclosing the diagnosis to patients and their families.

“Some details of the guideline will likely require modification as new tools and biomarkers become sufficiently validated for appropriate clinical use in real-world practice,” Alireza Atri, MD, PhD, chief medical officer of Banner Research, director of the Banner Sun Health Research Institute, based in Arizona, and lecturer on neurology at Brigham and Women’s Hospital and Harvard Medical School, said in the release.

According to the authors, a comprehensive evaluation includes laboratory tests and an MRI or, when MRI is not available, a CT scan. New specialized assessments like brain scans and spinal fluid tests will also have a critical role in the diagnostic formulation, they added.

When office-based cognitive assessments are not informative enough to diagnose the cognitive-behavioral syndrome, the workgroup recommends a neuropsychological evaluation. This should include “normed neuropsychological testing of the domains of learning and memory (in particular delayed free and cued recall/recognition); attention, executive function, visuospatial function, and language,” the authors wrote.

When the clinician is still uncertain of the diagnosis and cause, the guideline recommends obtaining more laboratory tests based on the patient’s medical, neuropsychiatric and risk factors.

When the clinician remains uncertain of the cause of an established cognitive-behavioral syndrome, the guideline recommends:

• molecular imaging with fluorodeoxyglucose PET to improve diagnostic accuracy;
• an analysis of cerebrospinal fluid for amyloid beta 42 and tau/phosphorylated tau profiles to assess AD neuropathologic changes; and, if still uncertain,
• an amyloid PET scan to assess cerebral amyloid pathology.

“We encourage clinicians to review these guidelines and incorporate them into their practice,” Maria C. Carrillo, PhD, chief science officer and medical affairs lead at the Alzheimer’s Association, said in the release. “These guidelines are important because they guide clinicians in the evaluation of memory complaints, which could have many underlying causes. That is the necessary start for an early and accurate Alzheimer’s diagnosis. In addition, these guidelines provide clinicians information about other underlying causes that may contribute to the memory complaints.”

References:

• Atri A, et al. Alzheimers Dement. 2024;doi:10.1002/alz.14335.
• Dickerson BC, et al. Alzheimers Dement. 2024;doi:10.1002/alz.14337.
• New clinical practice guideline on the process for diagnosing Alzheimer’s disease or a related form of cognitive impairment or dementia. https://www.alz.org/news/2024/clinical-practice-guideline-evaluation-alzheimers. Published Dec. 23, 2024. Accessed Dec. 30, 2024.