According to the American Brain Tumor Association, brain tumors can exhibit both general and specific symptoms. General symptoms are common to all brain tumors. Other symptoms are specific to the location of the tumor. These are termed "focal" or "localized" tumors, and they often reflect in some way the normal function of the part of the brain where they are located. Merck also warns that some tumors generate false localizing signs. These tumors mimic symptoms of a tumor in a particular location, but are actually elsewhere in the brain. Symptoms can occur whether the tumor is malignant or benign. Because brain tumor symptoms can be so variable, it is easy to misdiagnose the condition.
Headache
Headaches that are unresponsive to the usual remedies are a common first indicator of a tumor. Typically these headaches are at their worst early in the day, with a gradual improvement as the day passes. They are often accompanied by nausea and vomiting. The frequency and severity of the headaches may increase over a period of weeks or months until they become constant. Tumor headaches occur because of increasing pressure within the skull.
Seizures
Abnormal bursts of electricity in the brain may result in seizures. New onset seizures are another common first indication of a growing tumor. Seizures vary widely in severity, from the experience of odd and inexplicable smells or tastes, to muscle twitching, to problems with speech, to convulsions, to a loss of consciousness. These symptoms can make a brain tumor seem like epilepsy.
Mentation and Personality Changes
Brain tumors may cause short-term memory problems, confusion and difficulty with communication and concentration. Intellectual function may be impaired. Temperament, behavior and personality changes are also possible, similar to what happens with dementia.
Mass Effect
High pressure within the skull may cause brain structures to shift from their usual positions. This displacement may be observed through diagnostic imaging, or by an optometrist peering into his patient's eyes. A bulging optic nerve at the back of the eyeball is a characteristic sign of the mass effect. The mass effect can also result from a brain abscess due to an infection or other causes.
Specific Symptoms
The complexity of the brain permits only a sampling of the wide range of specific symptoms cited by Mayo clinicians and others. Some of the symptoms associated with frontal lobe tumors are one-sided paralysis, urinary frequency, impaired judgment and a loss of the sense of smell. Tumors to the basal ganglia may also cause one-sided paralysis. Occipital lobe seizures may result in blindness to one side of the visual field. Parietal lobe tumors may result in an inability to perform numerical calculations, difficulties with spatial orientation of the body and confusion in distinguishing left from right. Symptoms of brain stem tumors include one-sided facial drooping, a lack of coordination and drowsiness. Pituitary gland tumors result in a variety of hormone imbalances. For example, gigantism or acromegaly may occur if growth hormone is secreted to excess. Menstruation in women may cease, or the breasts of men may enlarge if prolactin production is increased. Symptoms of pineal tumors include drooping eyelids and the inability to look up. As previously indicated, the list goes on.
