Meningitis in adults can be caused by viruses, bacteria, Mycobacterium tuberculosis, fungi, and other pathogens, and the early symptoms and onset of meningitis vary from one pathogen to another. Most early meningitis cases have general symptoms such as fever, headache, vomiting, general malaise, fatigue, drowsiness, nausea, and vertigo. The neurological manifestations vary greatly in severity, from headache, dizziness, and cervical tonicity in mild cases to impaired consciousness, cranial nerve palsy, limb paralysis, urinary and fecal disorders, and convulsions in severe cases; with further development, the disease may even fall into a deep coma, presenting a decerebrate or decorticated state.