Cancer can cause seizures, which are bursts of abnormal electrical activity within the brain. These disruptions can lead to changes in awareness, muscle control, behavior, and senses. Cancer patients may experience them due to various direct and indirect mechanisms.
Brain Tumors and Seizures
Primary brain tumors, originating in brain tissue, directly cause seizures. A growing tumor disrupts the brain’s electrical pathways, irritating cells and leading to uncontrolled firing.
Tumors can also cause swelling (edema) or increased pressure within the skull. Both interfere with brain function and trigger seizures. Seizures are often an early symptom of a brain tumor, prompting medical evaluation. Both benign and malignant brain tumors can induce seizures, but malignant tumors are more commonly associated with seizure activity due to their faster growth and invasive nature.
How Cancer Elsewhere Can Trigger Seizures
Cancer originating elsewhere can also lead to seizures through indirect pathways. Brain metastases occur when cancer cells from primary tumors spread to the brain, forming secondary tumors. These metastatic tumors cause seizures by disrupting electrical activity, causing swelling, or increasing pressure, similar to primary brain tumors. Brain metastases are a common cause of seizures in adults with systemic cancer.
Paraneoplastic neurological syndromes are another cause. These rare conditions occur when the immune system mistakenly attacks healthy nervous system parts, including the brain, leading to neurological symptoms like seizures. Additionally, certain cancers or their treatments can cause metabolic imbalances, such as low sodium or high calcium levels. These imbalances disrupt the brain’s chemical environment, leading to impaired function and seizures. Some cancer treatments can also have neurological side effects that may include seizures.
Recognizing Seizure Symptoms
Seizures can manifest in various ways, from subtle changes to dramatic convulsions. Not all seizures involve obvious jerking movements or loss of consciousness. Symptoms depend on the affected brain area.
Generalized seizures involve widespread electrical activity affecting both sides of the brain, such as a tonic-clonic seizure with loss of consciousness, muscle stiffening, and rhythmic jerking movements. Focal seizures, also known as partial seizures, originate in a specific area of one side of the brain. These can present as localized twitching, numbness, tingling, or sensory changes without full awareness loss. Any new, unexplained neurological symptoms in a cancer patient should prompt immediate medical evaluation.
Diagnosis and Treatment Approaches
Diagnosing seizures in a cancer patient involves identifying the underlying trigger. Imaging studies like MRI or CT scans are frequently used to detect tumors, metastases, or other structural abnormalities. An electroencephalogram (EEG) measures brain electrical activity to pinpoint abnormal patterns. Blood tests check for metabolic imbalances contributing to seizures.
Treatment typically involves anti-seizure medications to control and prevent future episodes. Addressing the underlying cancer is often the most effective way to manage and resolve seizures. This can involve various cancer treatments like surgery, radiation therapy, chemotherapy, targeted therapies, or immunotherapy. Supportive care also helps manage symptoms and improve quality of life.