The neurologic patient can manifest signs that are secondary to dysfunction of other organ systems including the cardiovascular, endocrine, gastrointestinal and hematologic systems. This lecture will concentrate on how dysfunction of these systems can lead to secondary neurologic effects that can drastically affect the patient. Select cases will be presented in a case-based and "what's your diagnosis" format and audience participation is encouraged. For this reason, no exact diagnoses, nor discussion will be presented in these particular proceedings. It is important to remember that the nervous system is dependent upon the appropriate functioning of the other body systems to operate normally - this forces the clinician to evaluate the patient as a whole rather than dividing he/she up into separate parts or systems.