Neurologic evaluation of the optimally healthy oldest old

Area of Science:

• Gerontology and Neurology
• Aging research
• Clinical neuroscience

Background:

• The population aged 85 years and older is the fastest-growing demographic in the US.
• Limited data exists on the expected neurologic function in this specific age group.
• Understanding healthy aging is crucial for differentiating normal changes from disease.

Purpose of the Study:

• To characterize the clinical neurologic traits of optimally healthy individuals aged 85 years and older.
• To establish a baseline for normal neurologic function in the very old.

Main Methods:

• A community-based, longitudinal aging study.
• Inclusion of optimally healthy volunteers aged 85+ and healthy controls aged 65-74.
• Screening for absence of chronic disease and medication use.
• Standardized neurologic examinations coded into ordinal or interval variables.

Main Results:

• Significant differences between the oldest old and younger controls were observed in mental status, sensory function (smell, hearing, vibratory discrimination, stereognosis), oculomotor function, distal movement speed, and balance.
• Discriminant function analysis identified poor performance in balance (heel-toe walking, one-leg stance with eyes closed), smell, and visual pursuit as key predictors of belonging to the oldest group.
• These findings highlight specific neurologic domains most affected by healthy aging in advanced years.

Conclusions:

• Many neurologic signs observed in the very old are attributable to aging itself, not underlying disease.
• Deficits in balance, olfaction (smell), and visual pursuit are key indicators that differentiate healthy aging in the oldest old from younger elderly individuals.
• These identified neurologic traits provide valuable insights into the aging process in advanced age.