Dr. Edward Chang directs a clinical research program that focuses on outcomes, decision-making, and safety improvement of cutting-edge treatments for epilepsy and trigeminal neuralgia. His basic research laboratory is dedicated to discovering the basic cortical mechanisms of speech processing, and transforming those insights to innovative new brain mapping algorithms and assistive neuroprosthetic devices for paralysis.
Current Epilepsy Research Projects
Seizure freedom for the most intractable forms of epilepsy
Malformations of cortical development are a common cause of epilepsy that does not respond to medications. Seizure control outcomes after surgery can be highly variable because there are many types of cortical malformations. Using a new classification system devised by Dr. Barkovich, our team has determined factors that appear to be critical for achieving seizure freedom in patients with cortical dysplasia. Of the treatment-related factors, complete resection of the anatomical and electrocorticographic abnormality is the most important predictor of seizure freedom. We also identified a subtype of cortical dysplasia with a characteristic radiologic feature called a transmantle sign, which was first described at UCSF —this has a particularly good prognosis for seizure control after surgery.
UCSF Study Highlights Success of Brain Surgery for Severe Epilepsy, UCSF News
Chang EF, Wang DD, Barkovich AJ, Tihan T, Auguste KI, Sullivan JE, Garcia PA, Barbaro NM. Seizure freedom after surgery for malformations of cortical development. Annals of Neurology 2011;70(1):151-62.
Under-utilization of epilepsy surgery in the United States
In randomized trials, surgery has been unequivocally proven to be an effective treatment for temporal lobe epilepsy. Despite this, our research team documented that the utilization of epilepsy surgery in the United States continues to be under-utilized and many patients continue to suffer from seizures that might otherwise be controlled. Uninsured and racial minorities continue to be especially under-treated. These findings call for stronger adoption and practice of guidelines for evidence-based treatments in caring for epilepsy patients.
Brain Surgery for Epilepsy Underutilized, UCSF News
Englot DJ, Ouyang D, Barbaro NM, Garcia PA, Chang EF. Epilepsy surgery trends in United States, 1990-2008. Neurology 2012;17;78(16):1200-6.
'Come-and-Go' Epilepsy Surgery: The Radiosurgery or Open Surgery for Epilepsy (ROSE) Trial
UCSF is leading an international NIH-sponsored clinical trial to evaluate one of the most innovative new treatments for epilepsy. This study will evaluate the efficacy of radiosurgery as a non-invasive approach to treating temporal lobe epilepsy, while sparing cognition. The Study Center at UCSF reviews cases throughout the world and is actively recruiting patients are our own epilepsy center. Our team recently characterized the imaging changes that predict who might benefit from this new treatment option.
Chang EF, Quigg M, Oh MC, Dillon WP, Ward MM, Laxer KD, Broshek DK, Barbaro NM. Predictors of efficacy after stereotactic radiosurgery for medial temporal lobe epilepsy. Neurology 2010; 74(2):165-72. PMCID: PMC2809028
Epilepsy associated with brain tumors or cavernomas
Intractable epilepsy is commonly caused by brain tumors or vascular lesions. Symptomatic seizures can dramatically diminish patients’ quality of life and cause significant morbidity. Surgical removal of the lesion alone can leave behind disabling seizure foci that cannot be seen with conventional imaging such as MRI. UCSF Epilepsy Center neurosurgeon Edward Chang MD specializes in the use of preoperative magnetoencephalography and intraoperative direct cortical recordings called electrocorticography to tailor resective surgeries to remove extralesional seizure foci. With thousands of patients with lesional epilepsy treated at UCSF Medical Center, success rates for complete seizure control are up to 90 percent. Associated lesions include low grade gliomas, ganglioglioma, and dysembryoplastic neuroepithelial tumor (DNET).
Chang, EF, Potts, M, Keles, GE, Lamborn, KR, Chang, SM, Barbaro, NM, Berger, MS. Seizure characteristics and control following surgical resection in 332 patients with low-grade gliomas. J Neurosurg 2008;108(2):227-35.
Chang, EF, Christie, C, Garcia, PA, Sullivan, J, Tihan, T, Gupta, N, Berger, MS, Barbaro, NM. Seizure control outcomes after surgical resection of dysembryoplastic neuroepithelial tumor in 50 patients. J Neurosurg: Pediatr 2010;5(1):123-130.
Southwell D, Berger MS, Barbaro NB, Chang EF. Long-term seizure outcomes after resection of gangliogliomas. Neurosurgery 2012;70(6):1406-14.
Chang, EF, Gabriel, R, Potts, MB, Garcia, P, Barbaro, NM, Lawton, MT. Seizure characteristics and control after microsurgical resection of supratentorial cerebral cavernous malformations. Neurosurgery 2009;65(1):31-38.
Ongoing Epilepsy Research Projects:
• Innovating new methods for localization of epilepsy onset
• Predictors of long-term outcomes after epilepsy surgery
• ROSE trial of non-invasive Gamma Knife radiosurgery
Current Trigeminal Neuralgia Research Projects
The UCSF trigeminal neuralgia practice is one of the largest in the United States, with nearly 300 patient evaluations and 100 surgeries performed every year. High hospital volume has been associated with improved outcomes and low complication rates. UCSF provides comprehensive treatment options including microvascular decompression, GammaKnife, Cyberknife, and percutaneous radiofrequency lesioning. We are currently analyzing the UCSF experience to better tailor treatments options for patients with intractable facial pain.
Ongoing Facial Pain Projects:
• Trigeminal neuralgia surgical outcomes
• Intraoperative trigeminal nerve mapping
• Long-term predictors of pain control
• Improvement of radiosurgical accuracy
Current Brain Mapping Research Projects
Cortical Brain Mapping
UCSF has pioneered the use of intraoperative brain mapping to improve safety, while maximizing resection of brain tumors. We are developing novel behavioral testing protocols to assess the safest access corridors during awake surgery. The traditional method of brain mapping uses electrical stimulation of the brain surface, which can be inefficient and dangerous in patients with seizure disorders. Chang Lab has recently engineered a novel brain mapping algorithm using passive brain recordings and real-time signal processing. The results suggest stimulation mapping may be replaced with a safer and faster alternative.
Chang, EF, Clark, A, Smith, JS, Polley, MY, Chang, SM, Barbaro, NM, McDermott, MW, Berger, MS. Functional mapping-guided resection of low-grade gliomas in eloquent areas of the brain: improvement of long-term survival. J Neurosurg 2011; 114(3):566-73.
Cheung C, Chang EF. Real-time, time-frequency mapping of event-related cortical activation. J Neural Eng 2012;9(4):046018.