Bio

Clinical Focus


  • Neurosurgery
  • Neuro-oncology
  • Brain Tumors
  • Skull Base Tumors
  • Endoscopic Surgery
  • Neuroanatomy
  • Cancer Microenvironment

Professional Education


  • Board Certification: Neurosurgery, Royal College of Physicians and Surgeons of Canada (2011)
  • Residency:McGill University Health Center (2011) Canada
  • Internship:McGill University Health Center (2006) Canada
  • Medical Education:King AbdulAziz University (2003) Saudi Arabia

Publications

All Publications


  • Meningiomas of the tuberculum and diaphragma sellae. Journal of neurological surgery. Part B, Skull base Ajlan, A. M., Choudhri, O., Hwang, P., Harsh, G. 2015; 76 (1): 74-79

    Abstract

    Introduction Although tuberculum sellae (TS) and diaphragma sellae (DS) meningiomas have different anatomical origins, they are frequently discussed as a single entity. Here we review the radiologic and intraoperative findings of TS and DS meningiomas and propose a radiologic classification. Methods We retrospectively reviewed 10 consecutive TS and DS meningiomas. Data regarding clinical presentation, preoperative imaging, and intraoperative findings were analyzed. Three sellar dimensions were measured on magnetic resonance imaging (MRI): the tuberculum-sellar floor interval (TSFI), the planum-tuberculum interval (PTI), and the total height. Results Three distinct anatomical patterns were recognized: exclusively tubercular meningiomas (type A) were accompanied by elongation of the TSFI and, more significantly, of the PTI; combined TS and DS meningiomas (type B) were associated with relative elongation of both the PTI and TSFI; and the sole exclusively DS meningioma (type C) was associated with elongation of neither PTI nor TSFI. Conclusion Suprasellar meningiomas can be classified as tubercular, combined, or diaphragmatic based on preoperative MRI. Exclusively tubercular meningiomas (type A) require only a supradiaphragmatic approach. Tumor involvement of the sellar diaphragm (type B or C) requires resection of the diaphragm and thus a combined infra- and supradiaphragmatic approach.

    View details for DOI 10.1055/s-0034-1390400

    View details for PubMedID 25685653

  • The human factor and safety attitudes in neurosurgical operating rooms. World neurosurgery Ajlan, A. M., Harsh, G. R. 2015; 83 (1): 46-48

    View details for DOI 10.1016/j.wneu.2013.08.039

    View details for PubMedID 24012553

  • Endoscopic resection of a giant intradural retroclival ecchordosis physaliphora: surgical technique and literature review. World neurosurgery Choudhri, O., Feroze, A., Hwang, P., Vogel, H., Ajlan, A., Harsh, G. 2014; 82 (5): 912 e21-6

    Abstract

    To report the first complete resection of a giant ecchordosis physaliphora using an endoscopic transclival approach and to provide a current review of the literature.This rare benign lesion, originating from embryonic notochordal remnants, was located in the prepontine cistern of a 63-year-old man presenting with progressive tremor and imbalance. Preoperative imaging demonstrated a 2.1-cm intradural lesion abutting the pons and basilar artery and extending through the dura mater.A gross total resection was successfully achieved endoscopically without neurovascular compromise or additional complications. Postoperative histopathologic examination was consistent with a diagnosis of giant ecchordosis physaliphora.An endoscopic endonasal transclival approach provided a direct, minimally invasive route for safe and complete resection of this rare prepontine tumor, as it has for similarly located skull base chordomas. Our experience highlights the utility of endoscopy in visualization of both pathologic entities and nearby critical neurovascular structures in the management of ecchordosis physaliphora and other cranial base neoplasms.

    View details for DOI 10.1016/j.wneu.2014.06.019

    View details for PubMedID 24937599

  • Spontaneous Sphenoid Wing Meningoencephaloceles with Lateral Sphenoid Sinus Extension: The Endoscopic Transpterygoid Approach JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Ajlan, A., Achrol, A., Soudry, E., Hwang, P. H., Harsh, G. 2014; 75 (5): 314-323
  • Deep venous structures distortion in spontaneous intracranial hypotension as an explanation for altered level of consciousness. Journal of neurointerventional surgery Ajlan, A. M., Al-Jehani, H., Torres, C., Marcoux, J. 2014; 6 (7)

    Abstract

    Spontaneous intracranial hypotension (SIH) is a syndrome of low pressure headache associated with low CSF pressure. The condition is generally considered benign but extreme cases of SIH can lead to changes in the level of consciousness. We describe a case in which alteration in the level of consciousness was prolonged and severe, and could not be explained solely by the presence of subdural collections. MRI of the brain showed evidence of impaired venous flow secondary to brain sagging causing distortion of deep venous structures.

    View details for DOI 10.1136/neurintsurg-2013-010823.rep

    View details for PubMedID 24092865

  • Supratentorial low-grade diffuse astrocytoma: medical management. Seminars in oncology Ajlan, A., Recht, L. 2014; 41 (4): 446-457

    Abstract

    Diffuse astrocytomas (DAs) represent less than 10% of all gliomas. They are diffusely infiltrating World Health Organization (WHO) grade II neoplasms that have a median survival in the range of 5-7 years, generally with a terminal phase in which they undergo malignant transformation to glioblastoma (GBM). The goals of treatment in addition to prolonging survival are therefore to prevent progression and malignant transformation, as well as optimally managing symptoms, primarily tumor-associated epilepsy. Available data suggest that the course of this disease is only minimally impacted by adjuvant therapies and that there does not seem to be much difference in terms of outcome of whether patients are treated in the adjuvant setting with irradiation or chemotherapy. We review the experience with chemotherapy as a treatment modality and offer some guidelines for its usage and discuss medical management of arising symptoms.

    View details for DOI 10.1053/j.seminoncol.2014.06.013

    View details for PubMedID 25173138

  • Functional pituitary adenoma recurrence after surgical resection. World neurosurgery Ajlan, A. M., Harsh, G. R. 2014; 81 (3-4): 494-496

    View details for DOI 10.1016/j.wneu.2013.11.001

    View details for PubMedID 24215871

  • Spontaneous Sphenoid Wing Meningoencephaloceles with Lateral Sphenoid Sinus Extension: The Endoscopic Transpterygoid Approach J Neurol Surg B Ajlan, A., et al 2014

    View details for DOI 10.1055/s-0034-1372465

  • Meningiomas of the Tuberculum and Diaphragma Sellae J Neurol Surg B Ajlan, A. M., et al 2014

    View details for DOI 10.1055/s-0034-1390400

  • Supratentorial Low Grade Diffuse Astrocytoma: Medical Management Seminars in Oncology Ajlan, A., Recht, L. 2014
  • Perioperative Cerebrospinal Fluid Diversion Utilizing Lumbar Drains in Transsphenoidal Surgery Journal of Neurological Disorders Jung, H., Shah, A., Ajlan, A. 2014
  • Endoscopic Resection of a Giant Intradural Retroclival Ecchordosis Physaliphora: Surgical Technique and Literature Review World Neurosurgery Choudhri, O., Feroze, A., Hwang, P., Vogel, H., Ajlan, A., Harsh IV, G. 2014
  • Endoscopic transtubular resection of a colloid cyst NEUROSCIENCES Ajlan, A. M., Kalani, M. A., Harsh, G. R. 2014; 19 (1): 43-46

    Abstract

    Colloid cysts, benign outgrowths from the roof of the third ventricle, warrant resection when they become symptomatic. Historically, this has been performed by craniotomy and a transcortical or a transcallosal approach that employs a pair of fixed blade retractors and an operating microscope. Less invasive endoscopic techniques have employed rigid endoscopes with single or dual working channels. We report the use of a tubular retractor as a transcortical port to resect a third ventricular colloid cyst. A 29-year-old woman presented with headache. The brain imaging demonstrated a third ventricular colloid cyst. We describe transcortical, transforaminal resection of a colloid cyst using stereotactically guided placement of a tubular retractor, endoscopic visualization, and bimanual dissection with traditional microinstruments. The increased range of viewing angles of the endoscope within the cylinder of access maintained by the tubular retractor facilitates resection of the cyst through a smaller opening.

    View details for Web of Science ID 000331472900009

    View details for PubMedID 24419449

  • Deep venous structures distortion in spontaneous intracranial hypotension as an explanation for altered level of consciousness. BMJ case reports Ajlan, A. M., Al-Jehani, H., Torres, C., Marcoux, J. 2013; 2013

    Abstract

    Spontaneous intracranial hypotension (SIH) is a syndrome of low pressure headache associated with low CSF pressure. The condition is generally considered benign but extreme cases of SIH can lead to changes in the level of consciousness. We describe a case in which alteration in the level of consciousness was prolonged and severe, and could not be explained solely by the presence of subdural collections. MRI of the brain showed evidence of impaired venous flow secondary to brain sagging causing distortion of deep venous structures.

    View details for DOI 10.1136/bcr-2013-010823

    View details for PubMedID 24068443

  • Fahr's Disease Presenting with Aneurysmal Subarachnoid Hemorrhage. Journal of clinical imaging science Al-Jehani, H., Ajlan, A., Sinclair, D. 2012; 2: 27-?

    Abstract

    Fahr's disease is a rare disorder of slowly progressive cognitive, psychiatric, and motor decline associated with idiopathic basal ganglia calcification (IBGC) and widespread calcification in the brain and cerebellum. Acute presentation of IBGC is most often as a seizure disorder; however, we present a case of an acute IBCG presentation in which the cause of the deterioration was an aneurysmal subarachnoid hemorrhage.

    View details for DOI 10.4103/2156-7514.96542

    View details for PubMedID 22754741

  • Comparison Between Manual and Semiautomated Volumetric Measurements of Pituitary Adenomas SKULL BASE-AN INTERDISCIPLINARY APPROACH Al Hinai, Q., Mok, K., Zeitouni, A., Gagnon, B., Ajlan, A. R., Rivera, J., Tewfik, M., Sirhan, D. 2011; 21 (6): 365-371

    Abstract

    Linear measurements have many limitations. The aim of this study is to compare manual and semiautomated volumetric measurements of pituitary adenomas. Magnetic resonance imaging (MRI) scans of 38 patients with pituitary adenomas were analyzed. Preoperative MRI was acquired on a 1.5 T. MRI volumes of the pituitary adenomas were obtained by two methods: manual (MA) and semiautomated (SA). The concurrent validity for SA and MA methods on 38 patients in the form of correlation coefficient was 0.97 (p < 0.0001). The intraobserver and the interobserver correlation coefficients for SA volumes were both 0.98, as for the intraobserver MA volumes were 0.98. Although the results of both methods are comparable, analysis of volumetric measurements by SA method is more time-efficient than MA segmentation. Precision in volumetric measurement techniques is likely to increase reliability of posttherapeutic monitoring of pituitary adenomas.

    View details for DOI 10.1055/s-0031-1287677

    View details for Web of Science ID 000296182500004

    View details for PubMedID 22547962

  • DRR drives brain cancer invasion by regulating cytoskeletal-focal adhesion dynamics ONCOGENE Le, P. U., Angers-Loustau, A., de Oliveira, R. M., Ajlan, A., BRASSARD, C. L., Dudley, A., Brent, H., Siu, V., Trinh, G., Moelenkamp, G., Wang, J., Sadr, M. S., Bedell, B., Del Maestro, R. F., Petrecca, K. 2010; 29 (33): 4636-4647

    Abstract

    Malignant glioma invasion is a primary cause of brain cancer treatment failure, yet the molecular mechanisms underlying its regulation remain elusive. We developed a novel functional-screening strategy and identified downregulated in renal cell carcinoma (DRR) as a regulator of invasion. We show that DRR drives invasion in vitro and in vivo. We found that while DRR is not expressed in normal glial cells, it is highly expressed in the invasive component of gliomas. Exploring underlying mechanisms, we show that DRR associates with and organizes the actin and microtubular cytoskeletons and that these associations are essential for focal adhesion (FA) disassembly and cell invasion. These findings identify DRR as a new cytoskeletal crosslinker that regulates FA dynamics and cell movement.

    View details for DOI 10.1038/onc.2010.216

    View details for Web of Science ID 000281127400003

    View details for PubMedID 20543869

  • Morbidity in epilepsy surgery: an experience based on 2449 epilepsy surgery procedures from a single institution Clinical article JOURNAL OF NEUROSURGERY Tanriverdi, T., Ajlan, A., Poulin, N., Olivier, A. 2009; 110 (6): 1111-1123

    Abstract

    In this paper the authors aimed to provide information related to major and minor surgical and neurological complications encountered following stereoelectroencephalography and epilepsy surgery.Methods The authors performed a retrospective review of 491 and 1905 patients who underwent intracranial electrode implantation and epilepsy surgery, respectively, between 1976 and 2006 at the Montreal Neurological Institute. All intracranial electrode implantations and surgical procedures were performed by 1 surgeon (A.O.).A total of 6415 electrode implantations and 2449 surgical procedures were done. There were no deaths related to either procedure. There were no major complications after intracranial electrode implantation, and the risks of infection and intracranial hematoma were found to be 1.8 and 0.8%, respectively. The number of electrodes per lobe (p = 0.05) and number of lobes covered (p = 0.04) were significant risk factors for hematoma and infection. Regarding epilepsy surgery, there were no major surgical complications, and the overall minor complication rate was 2.9%. Infection was the most common complication (1.0%), followed by intracranial hematoma (0.7%). Significant risk factors associated with hematomas and infections were the number of reoperations (p = 0.001) and older patient age (p = 0.03). Minor and major neurological complication rates were 2.7 and 0.5%, respectively, and the rate of overall neurological morbidity was 3.3%. Hemiparesis was the most frequent neurological complication (1.5%).Based on the authors' experience, intracranial electrode implantation is an effective method with an extremely low morbidity rate. Moreover, epilepsy surgery is safe, especially in experienced hands.

    View details for DOI 10.3171/2009.8.JNS08338

    View details for Web of Science ID 000266460800001

    View details for PubMedID 19199440