Patients with symptomatic (v. symptomatic West Syndrome) infantile spasms have an identified underlying neurological disorder that directly causes the spasms. The number of neurological diseases that can result in spasms is enormous, but some of the major categories include intrauterine insults and infections, hypoxic-ischemic encephalopathy, malformations of cortical development, metabolic disorders, other genetic or chromosomal defects, meningitis (v. bacterial meningitis), tumors, and neurocutaneous syndromes.