The frontal lobe is the seat of personality. It contains the main motor area, which controls the movements of the entire body. Tumors in this region affect these main functions as well as causing a wide array of symptoms affecting many mental and physical functions. The precise symptoms each patient experiences depend on the location of the tumor, and which brain structures are adjacent to it.
Headaches
Frontal lobe tumors, like many other brain tumors, can cause headaches. Typically, these can be quite severe, are worse when lying down and can wake the patient from sleep. Nausea and vomiting are symptoms that often accompany headaches--all are caused by an increase in intracranial pressure due to the added mass of the tumor.
Motor Symptoms
Tumors that affect the primary motor control center, which is located at the back of the forntal lobe, may cause partial or complete paralysis on the other side of the body. If other parts of the frontal lobe are affected, muscle strength may be intact but gait may be clumsy and uncoordinated.
Personality
Tumors in the frontal lobe can cause several different patterns of personality change. As explained by "Adams and Victor's Principles of Neurology," some tumors cause disinhibition, leading to wild behavior that is uncharacteristic of the patient, such as overt sexual behavior in a previously prim and proper elderly person. Other tumors can cause abulia, or lack of motivation. Executive functions, meaning the capacity to plan ahead and think about consequences of actions, are impaired. Any drastic change in personality, whether accompanied by other symptoms or not, should raise the concern of a brain tumor.
Seizures
Seizures caused by frontal lobe tumors cause convulsive movements on the other side of the body, though they often spread, so that the patient loses consciousness and has convulsions on both sides of the body. As described in "Adams and Victor's Principles of Neurology," the eyes may be involved in the convulsion, moving together during the seizure so that the person gazes at the side opposite the lesion.
Vision and Smell
Frontal lobe tumors can press directly on the optic nerves or affect them somewhere along their path. The result is often loss of half of the visual field. The optic disc may be swollen, a condition known as papilledema. As Neurusurgery.mgh explains, tumors at the base of the frontal lobe can also affect the olfactory nerves, leading to a loss of smell.
References
- "Adams and Victor's Principles of Neurology"; Maurice Victor and Allan Ropper; 2001
- Neurosurgery.mgh: A Primer of Brain Tumors
- "Harrison's Principles of Internal Medicine, 17th Edition"; Antoni Fauci (ed); 2008
