Dementia - A Typical Case

Author: V. Dimov, M.D.
Reviewer: R. Christie, M.D.

An 81-year-old Caucasian female (CF), a widow for several years, lives alone in her house. She has no children or any other family, and does the shopping and cooking by herself. She is very friendly and sometimes ask her neighbor for help with the shopping.

She was stopped by the police for driving disoriented and confused, not knowing where she was going. She is hospitalized for further work-up.

What is the most likely diagnosis?

Remember the mnemonic DDD:

- Delirium? But why? What is the cause?
- Dementia?
- Depression?
- Subdural hemorrhage?

Past medical history (PMH)

Hypertension (HTN), hyperlipidemia, idiopathic thrombocytopenic purpura (ITP) (the last platelet count was 59), degenerative joint disease (DJD).

Medications

Danazol (for ITP), atorvastatin (Lipitor), lisinopril, PPI (Protonix), acetaminophen (Tylenol) PRN.

Social history (SH)

She lives alone, there are no living relatives.

What would be the next step in evaluation?

First, you need to do a MMSE - it is 20/30 (she had a high school diploma; remember that the normal MMSE score varies with the level of education).

She is a very friendly lady but extremely forgetful. She is oriented just to herself, not to place or time.

The physical exam is unremarkable.

What diagnostic tests would you suggest?

Next, you need to rule out any reversible cause:

-Infection - UTI, pneumonia
-Delirium
-Depression
-Hypothyroidism
-B12 deficiency
-Syphilis

The tests are:

- CBCD, CMP, UA, TSH, B12, B9, RPR
- Head CT or MRI

If you need to remember just 4, go for: TSH, B12, RPR and CT of the head.

What happened?

The patient was started on Aricept 5 mg po qd. Her neighbor was appointed as a guardian and she was admitted to an assisted living facility.

Final diagnosis

Alzheimer's dementia.

What did we learn from this case?

Dementia is common in the elderly. If we are lucky enough to live long enough, probably all of us will develop some degree of cognitive impairment.

If the patient does not have a family, a guardian should be appointed (through the court) to make health care decisions on behalf of the patient.

The MMSE is showing the progressive decline of a patient with Alzheimer's dementia over 5 years.

Summary

Dementia prevalence doubles every 5 years after age 60. It is rare below 65 (1%) but affects around 50% of those older than 85. Seventy percent of the elderly NH residents are demented. Median survival for incident dementia of 4.5 years.

There are 2 major causes of dementia in the elderly: Alzheimer's disease and vascular dementia.

Sixty percent of dementia is due to Alzheimer's disease, 15 percent is due to vascular disease and many of the remaining cases involve both Alzheimer's and vascular dementia in the same patient ("mixed dementia").

Diagnostic criteria for delirium

- Change in mental status (/\MS) not explained by dementia.
- /\MS developed over a short period of time (hours to days) and fluctuates
- /\MS could be explained by a drug, acute illness or metabolic disturbance

Diagnostic criteria for dementia

- Memory loss, impairment of language, praxis, recognition or abstract thinking
- Chronic and progressive
- Delirium ruled out

Delirium is attention disorder vs. dementia which is a memory disorder.

Diagnostic criteria for Alzheimer's disease

- Dementia is present, verified by MMSE
- Screening blood tests (CBC, BUN, Ca++, LFT, TSH, B12, B9, RPR) do not show any untreated cause
- Head CT or MRI are normal or show atrophy

Diagnostic criteria for vascular dementia

- Dementia is present, verified by MMSE
- Focal neurologic signs on exam
- Abrupt onset with stepwise progress or stroke-related
- Head CT or MRI show multiple strokes

References

Advances in the Treatment of Alzheimer's Disease - AFP 11/98.
Early Diagnosis of Dementia - AFP 02/01.
Tom DeBaggio's Alzheimer's Journey Continues - NPR 05/05 - "Five years ago, Tom told his personal story about the battle with early-onset Alzheimer's. A return visit finds him less sure of himself..." (a patient's perspective).
Cholinesterase inhibitors for Alzheimer's lack evidence - BMJ 8/05.
Delirium in Older Persons. Sharon K. Inouye, M.D., M.P.H., NEJM, Volume 354:1157-1165, March 16, 2006, Number 11.
Copyright vs. Open Access at the Bedside: MMSE form disappearing from textbooks, replaced by the Sweet 16 test - NEJM, 2011.
FDA Approves "Alzheimer's CT scan" by Eli Lilly - radioactive agent florbetapir tags clumps of sticky amyloid in brain. WSJ, 2012.

Published: 03/1/2005
Updated: 03/11/2012

1 comment: