Symptoms may progress despite the abatement of exposure. There are very few pathognomonic signs and symptoms that illicit the immediate neurotoxic diagnosis. Variations in symptom complex may mimic disorders of psychiatric, metabolic, nutritional, inflammatory, or degenerative natures. Common complaints may include numbness, tingling, pain, weakness, dizziness, and forgetfulness. Peripheral nervous system toxicity most commonly affects the limbs distally causing symptoms of numbness, tingling, burning pain, or weakness beginning with the fingers and toes first, then the hands, feet, legs, and forearms.
Symptoms often follow a classic stocking-glove distribution.
There seems to be a greater vulnerability of the longest nerve axons first with sensory dysfunction before motor involvement. Deficits are seen peripherally but intact proximal. Central nervous system toxicity may present a whole host of symptoms from altered cognition and personality features to balance, coordination, motor dysfunction and tremor. For example, manganese toxicity can cause Parkinsonism, while lead, arsenic, and mercury all can cause headaches and other CNS symptoms. Solvents frequently cause CNS depression and thus impair many of the body systems.