I have both clinical and basic science research interests. Clinical research flows naturally from my practice in pediatric neurointerventional radiology and my work with the Cerebrovascular Surgery and Interventions Center and the Vascular Anomalies Center, where we see a high volume of patients with very rare vascular conditions.
My clinical research in this area aims to deepen our understanding of cerebrovascular disease and to bring neurointerventional techniques, originally developed for adults, to children, often necessitating creative re-purposing of devices and approaches. We have also focused heavily on providing our treatments with the lowest possible levels of radiation.
In terms of basic imaging research, my group has focused on developing new magnetic resonance imaging techniques to allow us to visualize electrical discharges in the brain. Current techniques use metabolic changes and blood flow changes to visualize parts of the brain that are active, but these changes are several steps removed from the actual electrical neuronal activity that is the language of the brain. I have worked with a multidisciplinary group of researchers to develop a novel technique combining high-speed MR acquisition and simultaneous EEG to directly visualize areas of the brain in which there are abnormal electrical discharges in patients with epilepsy.
The short-term hope is that a technique like this can both be useful for more accurately identifying electrically abnormal regions in epilepsy patients. Ultimately, our hope is that this may develop into a broad tool that will help us understand the organization of brain activity and encoding. Patients with epilepsy provide an excellent model because of the frequent occurrence of large-scale electrical discharges in the brains of children with this condition.
In addition to imaging patients, we have also supplemented human imaging with magnetic resonance images of electrical current phantoms that we designed to mimic various aspects of the discharges in the brain. Additionally, we used an isolated preparation of the cerebellum of the turtle to study the imaging response when electrical current is injected into living brain tissue, without confounders such as blood flow and respiration.
My publications reflect both my clinical and basic imaging research interests. Here is a selection:
Orbach D, Ritaccio A, Devinsky O. Psychogenic, nonepileptic seizures associated with video-EEG-verified sleep. Epilepsia. 2003 Jan;44(1):64-68. PMID: 12581231
Viswanathan V*, Smith ER, Mulliken JB, Fishman SJ, Kozakewich HP, Burrows PE, Orbach DB. Infantile hemangiomas involving the neuraxis: clinical and imaging findings. AJNR Am J Neuroradiol. 2009 May;30(5):1005-1013. PMID: 19213817
Thiex R* , Mulliken JB, Revencu N, Boon LM, Burrows PE, Cordisco M, Dwight Y, Smith ER, Vikkula M, Orbach DB. A novel association between RASA1 mutations and spinal arteriovenous anomalies. AJNR Am J Neuroradiol. 2010 Apr;31(4):775-779. PMID: 20007727
Sundaram P*, Wells WM, Mulkern RV, Bubrick EJ, Bromfield EB, Munch M, Orbach DB. Fast human brain magnetic resonance responses associated with epileptiform spikes. Magn Reson Med. 2010 Dec;64(6):1728-1738. PMID: 20806355
Alomari AI, Chaudry G, Rodesch G, Burrows PE, Mulliken JB, Smith ER, Orbach DB. Complex spinal-paraspinal high-flow lesions in CLOVES Syndrome: Analysis of clinical and imaging findings. AJNR 2011;32:1812-7.
Sundaram P, Mulkern RV, Wells WM, Triantafyllou C, Loddenkemper T, Bubrick EJ, Orbach DB. An empirical investigation of motion effects in eMRI of interictal epileptiform spikes. MRI 2011;29:1401-9.
Ellis MJ, Armstrong D, Vachhrajani S, Kulkarni AV, Dirks PB, Drake JM, Smith ER, Scott RM, Orbach DB. Angioarchitectural features associated with hemorrhagic presentation in pediatric cerebral arteriovenous malformations. J Neurointerv Surg. 2012.
Ellis MJ, Amlie-Lefond C, Orbach DB. Endovascular therapy in children with acute ischemic stroke: review and recommendations. Neurology. 2012;79(13 Suppl 1):S158-164.
Walcott BP, Smith ER, Scott RM, Orbach DB. Dural arteriovenous fistulae in pediatric patients: associated conditions and treatment outcomes. J Neurointerv Surg. 2013;5(1):6-9.
Walcott BP, Smith ER, Scott RM, Orbach DB. Pial arteriovenous fistulae in pediatric patients: associated syndromes and treatment outcome. J Neurointerv Surg. 2013;5(1):10-14.
Orbach DB, Stamoulis C, Strauss KJ, Manchester J, Smith ER, Scott RM, Lin N. Neurointerventions in children: Radiation exposure and its import. AJNR Am J Neuroradiol. 2014 April. PMID: 24157736
Balasubramanian M*, Mulkern RV, Wells WM, Sundaram P, Orbach DB. Magnetic resonance imaging of ionic currents in solution: The effect of magnetohydrodynamic flow. Magn Reson Med. 2014 Oct 1. PMID: 25273917
Lin N*, Smith ER, Scott RM, Orbach DB. Safety of neuroangiography and embolization in children: complication analysis of 697 consecutive procedures in 394 patients. J Neurosurg Pediatr. 2015 Jun 26; 1-7. PMID: 26114994