2003 Research Fellow

Ira Garonzik, MD
Johns Hopkins Hospital

Laser evoked potentials to study human cortical pain-signaling pathways in patients with implanted grids and central nervous system lesions

The goal of this study is to understand human cortical mechanisms of the sensory and affective dimensions of pain. Little is known about the human cortical structures receiving nociceptive input or about the functions of these structures. Preliminary studies indicate that potentials evoked by a pure pain stimulus are localized over human anterior cingulate cortex (ACC) and parasylvian cortex, which suggests that these areas receive nociceptive inputs. Lesions of the parietal operculum are associated with deficits of pain discrimination (sensory-discriminative aspect of pain) while lesions of the ACC and insula tend to be associated with deficits of the motivation to escape from painful stimuli (affective-motivational aspect of pain). The present study is designed to determine whether the human ACC, postcentral gyrus and parietal operculum receive nociceptive input. Cortical activity will be monitored over ACC, parasylvian and paracentral cortex during cutaneous stimulation with a Thulium: Yag laser (laser evoked potentials - LEP) in epileptic patients with implanted subdural grids. Additionally, normal side to side differences in LEPs will be determined as a control for such differences in patients with lesions of the central nervous system (CNS). These studies have unique potential to clarify the identity, function and pathophysiology of pains-signaling structures in human cortex.

About Ira Garonzik

Dr. Garonzik currently is in his sixth year of residency in the Department of Neurosurgery at the Johns Hopkins Hospital. He graduated from the Johns Hopkins University in 1993, receiving a Bachelor of Arts degree in biology with general and departmental honors. While at the Johns Hopkins University, Dr. Garonzik was elected to Phi Beta Kappa during his junior year, played on the varsity football team and was awarded a
Barry Goldwater Research Scholarship for his work with Dr. Saul Roseman. In 1997, Dr. Garonzik graduated from the Emory University School of Medicine summa cum laude. While at Emory, Dr. Garonzik was elected to
Alpha Omega Alpha (AOA) during his junior year, served as president of the AOA chapter and was awarded the AOA Research Fellowship for his work with Drs. Mahlon DeLong and Jerrold Vitek.

Dr. Garonzik completed a general surgery internship at the Johns Hopkins Hospital prior to entering his neurosurgical training. He served as an assistant resident until 2000 and subsequently as chief resident of the pediatric neurosurgery service at the Johns Hopkins Hospital and of the Johns Hopkins Bayview Neurosurgical Service. From 2001 until the present, Dr. Garonzik has undertaken a fellowship in functional neurosurgery with Dr. Frederick Lenz at the Johns Hopkins Hospital. Dr. Garonzik has devoted his fellowship time to the study of the thalamic and cortical mechanisms of pain, as well as the effects of deep brain stimulation on movement disorders and chronic pain. Dr. Garonzik's clinical interests include functional and spinal neurosurgery, as well as neurooncology.

Dr. Garonzik has given numerous talks on the surgical treatment of movement disorders and has served as an instructor for the first year medical student neuroscience course at the Johns Hopkins School of Medicine. He is a resident member of the AANS, CNS and Movement Disorder Society. Dr. Garonzik is a native of Pikesville, Maryland and resides in Baltimore with his wife and children.