R. Loch Macdonald


Associate Scientist, Keenan Research Centre for Biomedical Science

Research Programs


Please note: Dr. Macdonald will not take students in summer 2019.

My major research interests are in the field of aneurismal subarachnoid hemorrhage and cerebral vasospasm. We are investigating causes of delayed neurological deterioration after subarachnoid hemorrhage using animal models and testing hippocampal electrophysiology and function, animal behavior, learning and memory and changes in gene expression and function. We also are studying mechanisms of large artery vasospasm after aneurismal subarachnoid hemorrhage and effects of intracerebral and subdural hemorrhage on the brain. All of this work is laboratory-based as well as clinical with clinical trials and patient-based studies conducted testing similar hypotheses.


Recent Publications

  1. Macdonald, RL, Katan, M. Haptoglobin and hemoglobin in subarachnoid hemorrhage: A tale of 2 globins. Neurology. 2019; :. doi: 10.1212/WNL.0000000000007399. PubMed PMID:30952791 .
  2. Mikhail, M, Ayling, OGS, Eagles, ME, Ibrahim, GM, Macdonald, RL. Association between weekend admissions and mortality after aneurysmal subarachnoid hemorrhage: the "weekend effect" revisited. J. Neurosurg. 2019; :1-7. doi: 10.3171/2019.1.JNS183185. PubMed PMID:30925472 .
  3. Taslimi, S, Ku, JC, Modabbernia, A, Macdonald, RL. Hemorrhage, seizures, and dynamic changes of familial versus non-familial cavernous malformation: systematic review and meta-analysis. World Neurosurg. 2019; :. doi: 10.1016/j.wneu.2019.02.115. PubMed PMID:30851471 .
  4. Eagles, ME, Tso, MK, Macdonald, RL. Cognitive Impairment, Functional Outcome, and Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage. World Neurosurg. 2019; :. doi: 10.1016/j.wneu.2018.12.152. PubMed PMID:30639483 .
  5. Macdonald, RL. Letter to the Editor. Limited data?. J. Neurosurg. 2018;130 (2):670-671. doi: 10.3171/2018.9.JNS182618. PubMed PMID:30554185 .
  6. Eagles, ME, Tso, MK, Macdonald, RL. Significance of fluctuations in serum sodium levels following aneurysmal subarachnoid hemorrhage: an exploratory analysis. J. Neurosurg. 2018; :1-6. doi: 10.3171/2018.3.JNS173068. PubMed PMID:30117765 .
  7. Hänggi, D, Etminan, N, Mayer, SA, Aldrich, EF, Diringer, MN, Schmutzhard, E et al.. Clinical Trial Protocol: Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Efficacy, and Safety Study Comparing EG-1962 to Standard of Care Oral Nimodipine in Adults with Aneurysmal Subarachnoid Hemorrhage [NEWTON-2 (Nimodipine Microparticles to Enhance Recovery While Reducing TOxicity After SubarachNoid Hemorrhage)]. Neurocrit Care. 2019;30 (1):88-97. doi: 10.1007/s12028-018-0575-z. PubMed PMID:30014184 .
  8. Darsaut, TE, Fahed, R, Macdonald, RL, Arthur, AS, Kalani, MYS, Arikan, F et al.. Surgical or endovascular management of ruptured intracranial aneurysms: an agreement study. J. Neurosurg. 2018; :1-7. doi: 10.3171/2018.1.JNS172645. PubMed PMID:30004285 .
  9. Ayling, OGS, Ibrahim, GM, Alotaibi, NM, Gooderham, PA, Macdonald, RL. Anemia After Aneurysmal Subarachnoid Hemorrhage Is Associated With Poor Outcome and Death. Stroke. 2018;49 (8):1859-1865. doi: 10.1161/STROKEAHA.117.020260. PubMed PMID:29946013 .
  10. de Oliveira Manoel, AL, Macdonald, RL. Neuroinflammation as a Target for Intervention in Subarachnoid Hemorrhage. Front Neurol. 2018;9 :292. doi: 10.3389/fneur.2018.00292. PubMed PMID:29770118 PubMed Central PMC5941982.
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Affiliations & Other Activities

  • Associate Scientist, Li Ka Shing Knowledge Institute, St. Michael’s Hospital
  • Professor, Department of Surgery, Division of Neurosurgery, University of Toronto