Lead poisoning is discussed elsewhere. Lead encephalopathy occurs mainly in children (adults are more likely to develop peripheral neuropathy), and it is more common in acute than in chronic poisoning. Clinical signs and symptoms include visual disturbances, delirium, convulsions, severe headaches, hypertension, and sometimes papilledema. CSF usually displays increased pressure. The cell count varies from normal to several thousand; the majority of patients have mild to moderate pleocytosis. Mononuclears usually predominate, but polymorphonuclears may occasionally be high, especially in patients with the more elevated cell counts. The CSF protein level may be normal or increased; the glucose level is normal. These findings may suggest a variety of conditions, such as meningitis or meningoencephalitis due to virus or fungus, or early bacterial meningitis.