Some disorders in the nervous system are vascular disorder such as a stroke, transient ischemic attack (TIA), subarachnoid hemorrhage, subdural hemorrhage and hematoma, and extradural hemorrhage. You could also get infections such as meningitis, encephalitis, polio, and epidural abscess. You could also get structural, functional, and degeneration.
The nervous system has three general functions, a sensory function, an interpretative function, and a motor function.