Symptoms

Seizures

The presence of a tumor in some brain locations can be irritating and cause the abnormal nerve cell electrical activity which is clinically manifest as seizures. The type of seizure frequently relates to the part of the brain involved by the tumor. Seizure types include, but are not limited to: grandmal seizures, focal motor seizures (twitching of face, hand or leg), non-formed visual hallucinations and "staring spells" (called absence seizures).

Neurological Deficit

Some brain tumors destroy the brain tissue in which they grow. Some infiltrating tumors do this by stealing nutrients from the normal cells in the brain; others do it by pressure exerted by a growing mass. The brain functions associated with the involved regions are therefore lost. For example, tumors arising in and destroying the patient's motor strip will result in weakness and ultimately paralysis of the face, arm and/or leg on the opposite side of the body. Tumors which destroy brain tissue in the occipital lobe will cause a partial blindness (hemianopsia- loss of part of the opposite visual field). Tumors at the skull base can damage cranial nerves causing blindness, double vision, loss of facial sensation, hearing loss, etc.

Increased Intracranial Pressure

The head (intracranial space) may be thought of as a closed box containing brain tissue, water (intracellular fluid, extracellular fluid, ventricular and spinal fluid) and blood within the blood vessels. A growing tumor and swelling which may exist around it increases the contents of this closed box. This will eventually result in an increase of pressure within the intracranial space. This will cause headaches, vomiting, sleepiness and eventually coma and death. In addition, the brain is hollow. Fluid filled cavities called ventricles located in the center of the brain make ventricular fluid, which looks just like water. The ventricular fluid flows, via a series of canals (third ventricle and aqueduct) and holes (foramina), through the center of the brain to the outside, where it is now called spinal fluid and can be absorbed normally. Any mass which compresses this pathway results in a blockage of the flow of this fluid. Fluid keeps getting produced within the ventricles. It can't get out and the cavities of the brain (ventricles) enlarge. This condition is called hydrocephalus. The increase of ventricular fluid within the closed box of the intracranial space also results in an elevation of intracranial pressure.