The correct answer is:

Feigned unilateral lower extremity weakness is suggested when no downward pressure on a hand holding the heel of the unaffected leg is felt when the patient is attempting to elevate the affected leg.

Educational Objective:

Discuss diagnostic examinations that can help clinicians distinguish feigned illness from physical pathology.

Key Point:

Testing for factitious blindness, pseudoseizure, feigned unconsciousness, or paralysis can assist in the differential diagnosis of these presentations.

Explanation:

The Hoover sign is positive if the clinician does not feel pressure from the affected heel when asking the patient with leg weakness to lift the unaffected leg (see Figure). This finding suggests feigned lower extremity weakness.

Feigned blindness can be diagnosed by rotating an optokinetic drum or rocking a mirror slowly back and forth in front of the patient (which will induce nystagmus or eye movements in the functional patient, but not in a patient who is blind).

A true seizure is likely to induce metabolic acidosis (if generalized tonic–clonic and significantly prolonged). Tongue biting and incontinence are more likely in true seizures.

True unconsciousness is suggested (but not guaranteed) if the patient allows a dropped hand to hit the face, whereas feigned unconsciousness is suggested if the patient avoids injury to the face when the arm is dropped.

Patients willing to undergo tests or procedures, no matter how painful or expensive, may have either true or feigned illness.

Figure:

Hoover Sign

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