Parthasarathy D. Thirumala, MD

Associate Professor
Co-Director, Center of Clinical Neurophysiology

Parthasarathy Thirumala




Parthasarathy D. Thirumala, MD, joined the Center of Clinical Neurophysiology in June 2008. Dr. Thirumala specializes in intraoperative neurophysiological monitoring to adult and pediatric neurosurgical, orthopedic, ENT, vascular and interventional neuroradiology procedures.

Dr. Thirumala completed his neurology residency and clinical neurophysiology fellowship training at the University of Pittsburgh Medical Center. He completed his internship in internal medicine training at Brookdale University Hospital and Medical Center in Brooklyn, N.Y. Prior to clinical training he completed his masters in biomedical engineering at the University of Illinois at Chicago. Dr. Thirumala completed his medical training in India at Stanley Medical College in Chennai, India.

Prior to joining the department, Dr. Thirumala was in private practice providing intraoperative neurophysiological monitoring services. His group was one of the largest physician groups in the country providing intraoperative neurophysiological to approximately 90 hospitals across 12 states in the United States.

His clinical and research interests include intraoperative neurophysiological monit-oring during expanded endonasal approach, functional cortical mapping during awake craniotomies, ICU EEG.

He has published over 30 peer reviewed articles, book chapters, and invited articles in the journals including Neurosurgery, Journal of Neurosurgery, and Journal of Clinical Neurophysiology. He has given lectures both nationally and internationally on the value of intraoperative neurophysiological monitoring.

Specialized Areas of Interest

Intraoperative neurophysiological monitoring; functional cortical mapping during awake craniotomies; neurophysiological monitoring during minimally invasive endonasal approach to skull base surgeries, electroencephalography in the intensive care unit and telemedicine.

Board Certifications

American Board of Clinical Neurophysiology: Intraoperative Monitoring
American Board of Psychiatry and Neurology: Subspecialty Clinical Neurophysiology
American Board of Psychiatry and Neurology
American Board of Neuroimaging
American Board of Neurophysiologic Monitoring

Hospital Privileges

Children’s Hospital of Pittsburgh of UPMC
Jameson Hospital
Magee-Womens Hospital of UPMC
Monongahela Valley Hospital
UPMC Braddock
UPMC Hamot
UPMC Horizon-Greenville
UPMC Mercy
UPMC Passavant
UPMC Presbyterian
UPMC St. Margaret
UPMC Shadyside

Professional Organization Membership

American Academy of Neurology
American Clinical Neurophysiology Society
American Medical Association
American Society of Neurophysiological Monitoring
American Society of Electroneurodiagnostic Technologists
American Telemedicine Association

Education & Training

MBBS, Stanley Medical College, 1997
MS, University of Illinois, Bioengineering, 2001
Residency, Neurology, University of Pittsburgh, 2006
Fellowship, Clinical Neurophysiology, University of Pittsburgh, 2007

Selected Publications

Thirumala PD, Krishnaiah B, Habeych M, Crammond DJ, Balzer J, Hearing outcomes after loss of brainstem auditory evoked potentials during microvascular decompression. Journal of Clinical Neuroscience 22(4):659-63, 2015.

Thirumala PD, Kumar H, Bertolet M, Habeych ME, Crammond DJ, Balzer JR Risk factors for cranial nerve deficits during carotid endarterectomy: a retrospective study. Clin Neurol Neurosurg 130:150-4, 2015.

Thirumala P, Meigh K, Dasyam N, Shankar P, Sarma KR, Sarma DR, Habeych M, Crammond D, Balzer J.  The incidence of high-frequency hearing loss after microvascular decompression for trigeminal neuralgia, glossopharyngeal neuralgia, or geniculate neuralgia. J Neurosurg 1:1-7, 2015.

Thirumala PD, Wang X, Shah A, Habeych M, Crammond D, Balzer JR, Sekula R. Clinical impact of residual lateral spread response after adequate microvascular decompression for hemifacial spasm: A retrospective analysis. Br J Neurosurg 22:1-5, 2015.

Nwachuku EL, Yabes YG, Crammond DJ, Habeych ME, Balzer JR, Thirumala PD, Diagnostic Value of Somatosensory Evoked Potential (SSEP) Changes During Carotid Endarterectomy JAMA Neurol 72(1):73-80, 2015.

Habeych M, Thirumala PD, Crammond DJ, Balzer J Intraoperative neurophysiological monitoring of microvascular decompression for Glossopharyngeal neuralgia. Journal of Clinical Neurophysiology. J Clin Neurophysiol 31(4):337-43, 2014.

Mohanraj S, Thirumala PD, , Habeych M, Crammond DJ, Balzer J.Appropriate time to establish baseline responses for brainstem auditory evoked potentials during microvascular decompression for hemifacial spasm. J Clin Neurophysiol 31(5):500-4, 2014.

Thirumala PD, Bodily L, Tint D, Ward TW, Deeney VF, Crammond D, Habeych ME, Balzer JR. Somatosensory evoked potential monitoring during instrumented scoliosis corrective procedures: validity revisited. Spine J 14(8):1572-80, 2014.

Thirumala PD, Krishnaiah B, Habeych M, Crammond DJ, Balzer J Analysis of Wave III of Brain stem Auditory Evoked Potential Waveforms During Microvascular Decompression of Cranial Nerve VII for Hemifacial Spasm. J Clin Neurophysiol 31(2):127-32, 2014.

Ying T, Thirumala P, Chang Y, Habeych M, Crammond D, Balzer J. Emprical factors associated with Brainstem auditory evoked potential monitoring during microvascular decompression for hemifacial spasm and its correlation to hearing loss. Acta Neurochir (Wien) 156(3):571-5, 2014.

A complete list of Dr. Thirumala's publications can be reviewed through the National Library of Medicine's publication database.

Research Activities

1) Auditory Evoked Potential Alarm Criteria for Hearing Loss

Evaluate changes in brainstem auditory evoked potentials as an alarm criteria during MVD to prevent hearing loss. A retrospective series of 291 patients who underwent microvascular decompression at UPMC for trigeminal neuralgia, hemifacial spasm, geniculate neuralgia, or glossopharyngeal neuralgia with intraoperative monitoring were collected. The diagnostic accuracy of BAEPs were compared to pre and post-operative PTA and SDS scores using ROC curves, sensitivity, specificity, POR, and NOR. The amplitude and latency of BAEPs were analyzed separately. A comparison of ROC areas and testing for covariates was performed.

We found that the latency of wave V ROC had an AUC of 0.671 (95% CI: 0.534-0.808). The optimal cutoff point for latency change was ≥20% increase with a sensitivity of 0.786 (95% CI: 0.497-0.951) and specificity 0.563 (95% CI: 0.503-0.622). The amplitude of wave V ROC had an AUC of 0.723 (95% CI: 0.590-0.857). The optimal cutoff point for amplitude change was ≥ 50% reduction with sensitivity 0.714 (0.419-0.914) and specificity 0.668 (0.609-0.723). 

BAEPs predict hearing loss after MVD to a moderate degree. A 10% latency increase is appropriate for use as the primary alarm. A 50% amplitude of wave V reduction has been shown to be quite is predictive of hearing loss, and therefore unsuitable for use as an alarm. A latency change with an amplitude change or vice versa is more predictive of hearing loss than either alone, and therefore unsuitable for use as an alarm. 

2) Diagnostic Accuracy of Motor Evoked Potentials to Detect Neurological Injury during Idiopathic Scoliosis Correction: Meta-Analysis and Systematic Review

The goal of this study was to evaluate the efficacy of intraoperative TcMEP monitoring in predicting impending neurological deficit during corrective spinal surgery for patients with idiopathic scoliosis. The authors searched the PubMed and Web of Science database for relevant lists of retrieved reports and/or experiments published from January 1950 through October 2014 for studies on TcMEP use during idiopathic scoliosis surgery. The primary analysis of this review fit the operating characteristic into a hierarchical sROC model to determine the efficacy of intraoperative TcMEP monitoring. Thirteen studies, with a total of 2,602 idiopathic patients were included. There was an observed incidence of 1.19% (31/2602) in the sample population. Of the patients who sustained a neurological deficit, 77.4% (24/31) also had irreversible TcMEP change, and 22.6% (7/31) did not. The pooled analysis using the bivariate model showed TcMEP change with sensitivity (average [95% CI]: 94% [36%-100%]) and specificity (average [95% CI]: 97% [93%-98%]). The diagnostic odds ratio of a patient who had new neurological deficit with TcMEP change was calculated to be 441 (95% CI: 14 -14345). TCMEP showed high discriminant ability with an area under the curve of 0.98. New neurological deficit resulting from idiopathic scoliosis surgery was 441 times more likely to have changes in TcMEP compared to those without new deficit. Our findings from 2,602 operations on idiopathic patients show that TcMEP monitoring is a highly sensitive and specific test for detecting new spinal cord injuries in patients undergoing corrective spinal surgery for idiopathic scoliosis.