Brain tumor symptoms vary greatly from person to person because of two factors: location and size of tumors. The size of a tumor, however, does not necessarily affect the severity of symptoms. Manifestations depend on the cause of the symptoms: an increase in ICP, direct compression of gray or white matter, shifting of intracranial contents, or secondary cerebral ischemia. Symptoms may be non-specific and include headache, altered mental status, ataxia, nausea, vomiting, weakness, and gait disturbance. Left-sided weakness may be seen in a patient with a tumor pressing on the contra-lateral motor strip or speech difficulties may occur if a tumor is in the dominant hemisphere. Up to a third of people report having seizures prior to being diagnosed with a brain tumor. Rarely, brain tumor can present with psychiatric symptoms but without other neurological signs or symptoms. Evaluation for brain tumor is indicated in any patient with chronic, persistent headache associated with protracted nausea, vomiting, seizures, changes in headache pattern, neurologic symptoms, and change in personality.