MODULE SUPPLEMENT: NEUROLOGICAL SYSTEM
Cognitive Impairment--Differential Diagnosis

Many older adults complain about memory problems. Yet when talking about cognitive changes in older adults, it's necessary to differentiate a number of different causes ranging from what is sometimes termed "benign senile forgetfulness" or "age associated memory impairment", to mild cognitive impairment, to acute changes in cognition, to the various types of dementing processes that interfere with normal functioning.

Mild cognitive impairment is getting increased attention because data suggest that this may be an early indicator of an evolving dementia (Peterson, et al., 2001). However, the overlap between what is termed "benign" or "age associated" and more significant changes that predict further cognitive decline is not yet clearly outlined. Yet with more therapies being developed that are designed to delay the progression of cognitive decline, early diagnosis may become increasingly important.

Consider the following situation:

An elderly woman is brought to the emergency room at about 11 p.m. by the police who were called by a couple who noted someone was trying to enter their apartment. When the police approached the woman, she become abusive, confused and frightened. She looked pale and agitated and, because the police could not establish an address, they brought her to the emergency room for evaluation. On exam it takes several attempts to gain her attention to answer any questions but once focused on the question she rambles on in a disorganized way. She is unable to describe where she is, who she is, or where she lives. She does, however, appear clean, well-nourished, and not self-neglected. There are no signs of injury and on neurological exam you find no localizing or lateralizing signs, but she is only intermittently cooperative and her mental status continues to fluctuate.

Discussion Point: As an exercise, write a brief note from your specialist’s perspective about what your evaluation of this case would be. Is she demented? Delirious? If the latter, what would help you differentiate this from a dementia? Could she be demented and delirious? Consider how you might approach this situation. When you have finished answering these questions, continue with the course content.