By: Marae R. Laws
Introduction
Epilepsy is a complex neurological disorder that affects millions of people worldwide, with causes ranging from genetic factors to brain injuries and abnormal brain growths. Among the latter, benign brain tumors represent a unique subset of non-cancerous masses that can still significantly impact neurological health. While benign tumors do not spread to other parts of the body as malignant tumors do, their presence within the brain can disrupt normal brain activity, particularly when located in regions prone to seizure development.
Three types of benign tumors are most commonly associated with epilepsy: gangliogliomas, dysembryoplastic neuroepithelial tumors (DNETs), and hypothalamic hamartomas. Each of these tumors has distinct characteristics and effects, from focal seizures and memory disruptions to unique seizure types, like gelastic seizures associated with hypothalamic hamartomas. Understanding how benign tumors can cause epilepsy, recognizing symptoms, and exploring treatment options can be vital for individuals living with tumor-related epilepsy and for advancing supportive care options.
What are Benign Tumors?
Just as with all tumors, a benign tumor can be defined as a mass of abnormally growing cells. However, unlike malignant tumors, which are a type of cancerous tumor that spreads uncontrollably throughout the body, benign tumors are noncancerous and do not metastasize. With regard to epilepsy, there are three types of benign tumors that are associated with seizures. These include gangliogliomas, dysembryoplastic neuroepithelial tumors (DNETs), and hypothalamic hamartomas.
Gangliogliomas are rare, slow-growing tumors that contain both neuronal (nerve) and glial (supportive) cells, making them unique among brain tumors. These tumors are often associated with chronic focal epilepsy, especially in children and young adults. They are a common cause of intractable (drug-resistant) epilepsy. Typically found in the temporal lobe, gangliogliomas can lead to focal seizures, cognitive impairments, and personality changes due to their effect on nearby brain structures.
DNETs are rare, benign tumors that arise from glial and neuronal cells and are classified as “developmental” tumors, likely forming during brain development. These tumors are highly epileptogenic, meaning they have a strong tendency to cause epilepsy, especially in children and adolescents. Seizures associated with DNETs are often resistant to medication. DNETs are most commonly found in the temporal lobe and are typically characterized by focal seizures without other neurological deficits. Due to their stable nature, they rarely grow or become malignant.
Hypothalamic hamartomas are benign, non-cancerous masses in the hypothalamus that contain a mix of normal but disorganized brain tissue. These tumors are strongly associated with gelastic seizures (characterized by sudden bursts of laughter), which often begin in early childhood and may progress to other seizure types as the child ages. They can also cause precocious puberty and behavioral problems. Located in the hypothalamus, these tumors can disrupt hormonal regulation, behavior, and cognitive function in addition to causing seizures, often leading to significant challenges in management.
How Benign Tumors can cause epilepsy
Tumor Impact on Brain Activity: While benign tumors aren’t cancerous, their presence in the brain can disrupt normal function. As a tumor grows, it may put pressure on nearby neurons, leading to abnormal electrical signals. This interference can irritate the brain, triggering seizures.
Hyper-Excitable Neurons: Some benign tumors, like gangliogliomas or DNETs, are made of neuron-like cells that create an environment ripe for over-excitation. This essentially “primes” certain parts of the brain for seizures, with neurons firing too easily and spontaneously.
Role of Tumor Location: The exact location of a benign tumor can significantly influence the type of seizures experienced. For example, tumors in the temporal lobe often cause focal seizures that may involve memory or emotional responses, while hypothalamic hamartomas can trigger rare seizure types like gelastic (laughing) seizure
Symptoms and Diagnosis
Symptoms: The primary symptom of benign tumor-related epilepsy is focal seizures, but other effects can vary. Temporal lobe tumors, for instance, might lead to déjà vu, fear, or personality changes. Hypothalamic tumors, on the other hand, may cause unique symptoms like involuntary laughter, cognitive difficulties, or hormonal imbalances, all of which are important clues for diagnosis.
Diagnosis: Diagnosing epilepsy due to benign tumors generally involves imaging like MRIs or CT scans, which help identify tumor size and location. An EEG (electroencephalogram) is often used to detect abnormal brain wave activity, pinpointing the seizure’s origin. In certain cases, a biopsy may be necessary to confirm the tumor is benign and understand its cell type, guiding more targeted treatment.
Prognosis and Quality of Life
Prognosis: Overall, the prognosis for individuals with benign tumor-related epilepsy is often positive, particularly when the tumor can be safely removed or effectively managed. Some benign tumors grow very slowly or may not grow at all, which reduces their impact over time. However, managing epilepsy symptoms remains a priority to maintain a high quality of life.
Quality of Life: Long-term quality of life can vary, depending on factors like seizure control, treatment side effects, and cognitive impact. With modern treatments—like precise surgical options, anti-seizure medications, and even targeted radiation—many people with benign tumors leading to epilepsy can manage their condition well. Ongoing monitoring, support from epilepsy specialists, and lifestyle adjustments also play a big role in optimizing outcomes.
Conclusion
While benign tumors in the brain may not carry the same immediate risks as malignant tumors, their potential to cause epilepsy and disrupt cognitive, behavioral, and physical well-being makes them a serious concern. Fortunately, advances in diagnostic tools such as MRI and EEG, along with evolving treatment approaches like surgical resection and anti-seizure medications, offer promising outcomes for patients with tumor-related epilepsy. The prognosis for individuals with benign brain tumors causing epilepsy is generally favorable, especially when effective management strategies are in place. For many, quality of life is supported not only by medical interventions but also by continuous monitoring, support from specialized healthcare teams, and lifestyle adaptations that minimize seizure triggers. Further research into these tumors and their mechanisms can hopefully bring new insights, leading to improved care and support for those affected by epilepsy tied to benign brain growths.
Resources:
Cleveland Clinic (2024). Benign Tumor: Definition, Types, Causes & Management. Cleveland Clinic. Retrieved from: https://my.clevelandclinic.org/health/diseases/22121-benign-tumor
John Hopkins Medicine (2024). Brain Tumor Types. John Hopkins Medicine. Retrieved from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/brain-tumor/brain-tumor-types
Maschio, M. (2012). Brain Tumor-Related Epilepsy. Current Neuropharmacology, 10(2), 124-133. https://doi.org/10.2174/157015912800604470
UT Health San Antonio MD Anderson Cancer Center (2020). Benign Brain Tumors. Mays Cancer Center, UT Health San Antonio MD Anderson Cancer Center. Retrieved from: https://cancer.uthscsa.edu/cancer-care/types-and-treatments/benign-brain-tumors
University of Virginia Health (n.d.). Benign Brain Tumors FAQ’s. UVA Health. Retrieved from: https://uvahealth.com/services/benign-brain-tumor/faqs
