What is a focal seizure?
Seizures happen when there is a sudden surge of abnormal electrical activity in the brain. While most seizures begin with a disturbance throughout the entire brain, a focal seizure starts in one specific area of the brain. Often, these areas have been affected by injury, disease, or abnormal development. Some focal seizures remain limited to that area, while others may spread and become generalized.
Penn Medicine provides expert care for people with various neurological conditions, including focal seizure disorders. We offer access to advanced therapies based on research to improve the diagnosis, treatment, and long-term management of these conditions. Our multidisciplinary team members, including neurologists, epileptologists, neurosurgeons, and advanced imaging specialists, collaborate to deliver individualized care tailored to your needs.
Characteristics of focal seizures
Focal seizures are commonly described based on whether a person remains aware during the episode. In focal aware seizures, the person stays conscious. In focal impaired awareness seizures, awareness or responsiveness is reduced.
Focal seizures are also categorized by symptoms affecting movement or sensory changes. Symptoms may be subtle or more noticeable and can include:
- Muscle twitching, jerking, or stiffness in one part of the body
- Repetitive movements like lip-smacking or hand motions
- Tingling, numbness, or unusual smells or tastes
- Sudden emotional changes, including fear, anxiety, or déjà vu
- Changes in awareness, such as staring, confusion, or difficulty responding
Symptoms typically last several seconds to a few minutes and may be followed by brief confusion or fatigue.
What causes focal seizures?
Focal seizures often begin in areas of the brain that have been damaged or that developed in unusual ways. Common causes include:
- Stroke
- Traumatic brain injury
- Brain tumors or vascular abnormalities
- Infections affecting the brain
- Scarring from prior brain injury or surgery
First-time seizures in adults may be linked to stroke, head trauma, infection, metabolic disturbances, or underlying neurological conditions. In some cases, no clear cause is identified despite thorough evaluation.
Confirming a focal seizure diagnosis
Diagnosis begins with a review of a person’s medical history and symptoms. Doctors may also ask family members or others who saw the seizure to describe what happened. Imaging tests may uncover causes like tumors, scar tissue, or past brain injury. Blood tests may be performed to check for problems in the body that could trigger seizures. Tests to measure electrical activity in the brain show where seizures begin or even capture seizures as they happen, which helps to pinpoint the type of seizure.
Treating focal seizures
Treatment for focal seizures depends on their frequency, cause, and response to therapy. Your Penn Medicine care team will recommend treatment options based on your specific needs. Options may include medications to reduce or prevent seizures and lifestyle strategies to manage triggers such as sleep deprivation or stress. Neurostimulation therapies use mild electrical signals to help regulate abnormal brain activity, reducing frequency and severity of seizures. Treatment focuses on controlling your seizures, while supporting your safety, daily activities, and quality of life.