Exposure to chemical substances can cause adverse effects on the nervous system (Neurotoxicity). Chemicals toxic to the central nervous system can induce confusion, fatigue, irritability, and other behavioral changes. Exposure to methyl mercury and lead cause central nervous system toxicity, and can also cause degenerative diseases of the brain (encephalopathy). Chemicals toxic to the peripheral nervous sytem affect how nerves carry sensory information and motor impulses from the brain to the rest of the body. The organic solvents carbon disulfide, n-hexane,and trichloroethylene can harm the peripheral nervous system, resulting in weakness in the lower limbs, tingling in the limbs (paresthesia), and loss of coordination.