Answer to Medical Challenge | Altered Mental Status

Posted on October 26, 2011

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**If you would like another chance to read the challenge before seeing the answer, click here.  Scroll down for the answer.  **

 

 

 

 

 

 

The answer is:  B – Alzheimer’s disease

Because the clock drawing test examines higher order congenitive functioning it can be used to examine the frontal lobe (executive function). The reversed numbers on the clock are seen in dementia that affects the executive function, particularly Alzheimer’s and occasionally frontotemporal dementia, which was not a choice here, but would present with behavior disturbances.

Explanations:

A) Lewy body dementia is a possibility because it also has frontal/executive loss but this type of dementia is commonly associated with visual hallucinations and and Parkinsonian signs.

C) Normal pressure hydrocephalus (NPH) is relatively uncommon and should be suspected by the clinician when a patient presents with the classic triad of dementia, gait disturbance and urinary or bowel incontinence (the patients are thus said to be “wacky, wobbly, and wet”).  NPH can occur in conjunction with Alzheimer’s, but is important to consider because it is potentially reversible through introduction of a ventriculoperitoneal shunt.

D)  One would not expect this patient’s medications to cause delirium, but it is important to recognize that delirium and dementia are not mutually exclusive and can be present at the same time.  Delirium (most often due to medications and infections) is characterized by fluctuating level of consciousness with an acute onset.  Demented patients should display a stable level of consciousness, though their level of functioning may vary (family members will say they have “good days and bad days”).

E) Any infarct type dementia such as a lacunar stroke should display sudden focal changes like one-sided motor or sensory loss, problems with speech or comprehension, or some other focal, localizable neurologic deficit.

More information:

Alzheimer dementia is the most common type of dementia, followed by vascular (multi-infarct) dementia which presents with a stepwise decline in cognitive function.  Approximately 5% of people >65 years and 20% of people >80 years have some kind of dementia.  In all patients suspected to have dementia, one must first consider reversible causes such as vitamin deficiencies, hypothyroidism, infectious diseases, and normal pressure hydrocephalus.  Especially in the elderly, depression must be ruled out (known as pseudodementia).

Research on genetic and environmental risk factors for Alzheimer dementia is providing us with guidelines to reduce the risk of developing the disease, but those who are already diagnosed should live in a structured, predictable environment, preferably surrounded by familiar faces.  They should also be assessed for unnecessary anti-cholinergic medications, and should consider anti-cholinesterases (Donepezil) for maintaining cognitive function and SSRIs for concomitant depression.

Primary caregivers are the most important component of therapy for Azlheimer’s patients – they must be educated about what to expect, and should have their ability to cope assessed as they often grow overwhelmed themselves.

Thanks for participating, and thanks to Vince for contributing the case.  If you would like to submit a case or guest post, please use the contact page.  Check back for the next challenge, which I promise will be a very unique scenario.

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Posted in: Medicine