A neurologic evaluation should be performed if a patient has slowly increasing signs of mental dysfunction, new seizures or persistent headaches or if there is evidence of pressure inside the skull (e.g., vomiting, swelling or protrusion of the blind spot at the back of the eye).
A neurologist (a doctor who has received special additional training in the diagnosis and treatment of disorders of the brain, spinal cord and nerves) may order a magnetic resonance imaging (MRI) or computed tomography (CT or CAT) scan, as well as chest X-rays, to determine if the tumor has spread from another part of the body. An MRI usually finds low-grade astrocytomas earlier than CT. Cerebral angiography is rarely used to diagnose a brain tumor but may be done before surgery.
Depending on the patient's symptoms, specialized tests may be performed, including tests of the field of vision, the sharpness of vision and hearing. If the results of other tests are not conclusive, an examination of the fluid that surrounds the brain and spinal cord may be done. Although this is usually unnecessary, it is essential for diagnosing chronic or subacute meningitis or for identifying benign hypertension inside the skull.