Patients with symptoms and signs of central nervous system dysfunction frequently present to outpatient clinics and emergency departments. Disturbances of consciousness and cognition, headache, vertigo, dizziness or light-headedness, seizures, hemiparesis or hemisensory deficits, and other motor dysfunctions may be due to diseases of internal medicine in up to 50% of cases apart from exclusively neurological diseases. A neurological syndrome oriented analysis of each clinical case allows the exact differential diagnosis of the causes of the disease. A combined approach of internal medicine physicians and neurologists is often warranted.