Symptoms.
Functional limb weakness, or paresis, usually presents as unilateral weakness, but monoparesis and paraparesis also occur. Complete paralysis is rarer. About 50% of patients present acutely. Left-sided symptoms are not clearly more common than right. Patients may report dropping things, knees giving way, or that their limb feels alien or “not part of them.”
2. Physical examination.
a. Hoover’s sign is positive when there is weakness of hip extension, which improves when the patient flexes their contralateral unaffected hip against resistance (Fig. 33.2). It can be performed with the patient sitting or lying. The patient may need to be asked to focus attention on the unaffected limb.
b. Hip abductor sign is similarly positive when there is weakness of hip abduction, which improves when the patient abducts their contralateral hip against resistance.
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c. Dragging gait. A typical dragging gait of functional leg weakness involves the forefoot remaining in contact with the ground rather than the circumducting gait of an organic hemiparesis. There may be internal or external hip rotation.
d. Global pattern of weakness involving flexors and extensors equally
e. Give-way weakness describes transiently normal power, which then gives way and is a feature of variable weakness.
f. Discrepancies of movement. For example, inability to plantarflex ankles but able to stand on tip toes and walk from the waiting room or inability to grip examiner’s hand compared to getting an object out of a bag.
g. Drift without pronation. There is some evidence that drift without pronation, the downward drift of an arm without the pronating movement seen in pyramidal lesions, is more common in functional arm weakness than in patients with neurologic disease.