Vertigo Hearing loss Paresthesias Ataxia Headaches Seizures Somnolence progressing to stupor and coma Other manifestations may include heart failure, fatigue, and anorexia. Bruises, epistaxis, or gum bleeding may be noted. Ophthalmic examination may reveal decreased visual acuity, dilated retinal veins, sausage-linked retinal veins, or retinal hemorrhages. Neurologic examination may reveal various findings, including diminished mental status, confusion, ataxia, or nystagmus. Determine serum viscosity.
Serum viscosity is diagnostic in evaluating hyperviscosity syndrome.
The reference range is 1.4-1.8 units. Symptoms usually are not seen before the viscosity reaches 4 units, and hyperviscosity syndrome usually presents with a serum viscosity greater than 5 units. Obtain a peripheral blood smear. Rouleaux formation is often present with increased serum viscosity. Tailor additional workup to the patient's presentation.