Papers by Mehdi Zeinalizadeh
Spine, May 1, 2018
Study Design. Translation and cultural adaptation of the National Institutes of Health (NIH) Task... more Study Design. Translation and cultural adaptation of the National Institutes of Health (NIH) Task Force's minimal dataset. Objective. The purpose of this study was to evaluate validity and reliability of the Farsi version of NIH Task Force's recommended multidimensional minimal dataset for research on chronic low back pain (CLBP). Summary of Background Data. Considering the high treatment cost of CLBP and its increasing prevalence, NIH Pain Consortium developed research standards (including recommendations for definitions, a minimum dataset, and outcomes’ report) for studies regarding CLBP. Application of these recommendations could standardize research and improve comparability of different studies in CLBP. Methods. This study has three phases: translation of dataset into Farsi and its cultural adaptation, assessment of pre-final version of dataset's comprehensibility via a pilot study, and investigation of the reliability and validity of final version of translated dataset. Subjects were 250 patients with CLBP. Test-retest reliability, content validity, and convergent validity (correlations among different dimensions of dataset and Farsi versions of Oswestry Disability Index, Roland Morris Disability Questionnaire, Fear-Avoidance Belief Questionnaire, and Beck Depression Inventory-II) were assessed. Results. The Farsi version demonstrated good/excellent convergent validity (the correlation coefficient between impact dimension and ODI was r = 0.75 [P < 0.001], between impact dimension and Roland-Morris Disability Questionnaire was r = 0.80 [P < 0.001], and between psychological dimension and BDI was r = 0.62 [P < 0.001]). The test-retest reliability was also strong (intraclass correlation coefficient value ranged between 0.70 and 0.95) and the internal consistency was good/excellent (Chronbach's alpha coefficients’ value for two main dimensions including impact dimension and psychological dimension were 0.91 and 0.82 [P < 0.001], respectively). In addition, its face validity and content validity were acceptable. Conclusion. The Farsi version of minimal dataset for research on CLBP is a reliable and valid instrument for data gathering in patients with CLBP. This minimum dataset can be a step toward standardization of research regarding CLBP. Level of Evidence: 3
Neurosurgical Focus, Dec 1, 2018
Caspian journal of internal Medicine, 2022
Background: Post-neurosurgical meningitis is a significant cause of mortality and morbidity. In t... more Background: Post-neurosurgical meningitis is a significant cause of mortality and morbidity. In this study we aimed to compare the differences of clinical, laboratory features and outcomes between the post-neurosurgical meningitis caused by gram-negative bacilli (GNB) and gram-positive cocci (GPC).
Methods: Cases of post-neurosurgical meningitis (with positive CSF culture) were included. After classifying patients as GNB and GPC groups, clinical and paraclinical data were compared.
Results: Out of 2667 neurosurgical patients, CSF culture was positive in 45 patients. 25 (54.3%) were GNB, 19 (41.3%) GPC. The most common microorganisms were Klebsiella pneumoniae (n=14, 31.1%), Coagulase negative staphylococcus (n=8, 17.8%), Staphylococcus aureus (n=6, 13.3%), Acinetobacter baumannii (n=4, 8.9%), Pseudomonas aeruginosa (n=2, 4.4%), and Escherichia coli (n=2, 4.4%). There were no correlation between CSF Leakage, Surgical site appearance, presence of drain, Age and GCS between two groups (P=0.11, P=0.28, P=0.06, P=0.86, P=0.11 respectively). The only different laboratory indexes were ESR (86.8 mm/h vs. 59.5 mm/h, P=0.01) and PCT (13.1 ng/ml vs. 0.8 ng/ml, P=0.02) which were higher in GNB cases. 20% (n=5) of patients with GNB meningitis received preoperative corticosteroid, while none of GPC cases received (P=0.03). The median length of hospitalization for GNB and GPC cases was 56 and 44.4 days respectively (P=0.3).
Conclusion: The GNB antibiotic coverage should be designed more carefully in post-neurosurgical meningitis especially in patients with recent corticosteroid therapy and elevated ESR and procalcitonin.
World Neurosurgery, Sep 1, 2018
BACKGROUND: The endoscopic endonasal approach has recently become an acceptable option for resect... more BACKGROUND: The endoscopic endonasal approach has recently become an acceptable option for resection of all pituitary adenomas. We assessed biochemical outcome of endoscopic endonasal surgery in growth hormone (GH)e secreting adenomas, including remission rate, predictors of remission, and associated complications.-METHODS: Sixty-eight consecutive patients with acromegaly who underwent endoscopic endonasal surgery were analyzed prospectively. Tumors were classified according to size, Knosp grade, and Hardy-Wilson classification. Biochemical remission was defined as normal serum insulin-like growth factor 1 level and either a suppressed GH serum level less than 0.4 mg/L during an oral glucose tolerance test or a random GH level less than 1.0 mg/L at least 3 months after surgery.-RESULTS: Total biochemical remission rate was 64.7%. Gross total resection was achieved in 61 of the 68 patients (89.7%). Remission was achieved in 12 of 16 microadenomas (75%) and 32 of 52 macroadenomas (61.5%). Based on univariate logistic regression analysis, preoperative variables predictive of remission were age (P [ 0.004), Knosp grade (P [ 0.023), and preoperative GH levels (P [ 0.042). Three patients (4.4%) experienced postoperative panhypopituitarism, and permanent diabetes insipidus was seen in 4 patients (5.9%). Two patients (2.9%) developed cerebrospinal fluid leaks, which were treated by lumbar puncture in one case and early surgical repair in the other case.-CONCLUSIONS: Endoscopic endonasal adenoma resection leads to a high rate of endocrinologic remission in GHsecreting adenomas with a low complication rate. Patients with older age, higher preoperative GH levels, and higher Knosp grades are less likely to achieve remission.
Archives of Neuroscience, Jul 31, 2017
Background: Nowadays, the endoscopic transsphenoidal approach is the initial option for resection... more Background: Nowadays, the endoscopic transsphenoidal approach is the initial option for resection of all pituitary adenomas. The current study reported the experience with endoscopic transsphenoidal surgery remission rates using the 2010 consensus criteria, predictors of remission, and the associated complications. Methods: A prospectively collected database of 49 patients with acromegaly who underwent endoscopic endonasal transsphenoidal surgery was analyzed. Tumors were classified according to size, as well as the Knosp and the Hardy-Wilson classifications. Endocrinological remission was defined as normal insulin-like growth factor (IGF)-I level and either a suppressed growth hormone (GH) level < 0.4 ng/mL during an oral glucose tolerance test, or a random GH level < 1.0 ng/mL at least 3 months after the surgery. The extent of resection was evaluated on postoperative contrast-enhanced magnetic resonance imaging (MRI). Results: Biochemical remission was achieved in 7 of 9 (77.8%) microadenoma and 28 of 40 (70%) macroadenoma. The total remission rate was 71.4% and gross total resection was achieved in 45 of 49 (91.8%) patients. Tumor size, age, gender, history of prior surgery, suprasellar extension, and sphenoid sinus invasion were not associated with remission rate. Preoperative variables predictive of remission included the Knosp score (P = 0.041) and GH levels (P = 0.047). Two patients (4.1%) experienced postoperative pan hypopituitarism, and permanent DI was observed in 3 (6.1%) patients. One patient (2%) had cerebrospinal fluid (CSF) leaks treated with serial lumbar punctures. The median follow-up period was 25.45 months; ranged from 3 to 49. Conclusions: Endoscopic transsphenoidal adenoma resection leads to a high rate of endocrinological remission in patients with low acromegaly complication. Patients with high preoperative GH levels and the Knosp scores are less likely to achieve remission.
Case reports in clinical practice, Nov 29, 2021
Meningioma is a common primary tumor of the central nervous system and one of the most encountere... more Meningioma is a common primary tumor of the central nervous system and one of the most encountered brain tumors. Although classic histopathologic features of meningioma are relatively common and make its diagnosis straightforward, certain variants possess unusual histologic features causing diagnostic challenges. We reported three cases of clear cell meningioma, microcytic meningioma, and angiomatous meningioma report, variants with potential deceptive morphologies, and discuss their distinguishing morphologic features.
Operative Neurosurgery, May 3, 2017
Operative Neurosurgery, May 10, 2017
BACKGROUND Microvascular decompression for patients with trigeminal neuralgia (TGN) is widely acc... more BACKGROUND Microvascular decompression for patients with trigeminal neuralgia (TGN) is widely accepted as one of the modalities of treatment. The standard approach has been retrosigmoid suboccipital craniotomy with placement of a Teflon pledget to cushion the trigeminal nerve from the offending artery, or cauterize and divide the offending vein(s). However, in cases of severe compression caused by a large artery, the standard decompression technique may not be effective. OBJECTIVE To describe a unique technique of vasculopexy of the ectatic basilar artery to the tentorium in a patient with TGN attributed to a severely ectatic and tortuous basilar artery. A case series of patients who underwent this technique of vasculopexy for arterial compression is presented. METHODS The patient underwent a subtemporal transtentorial approach and the basilar artery was mobilized away from the trigeminal nerve. A suture was then passed through the wall of the basilar artery (tunica media) and secured to the tentorial edge, to keep the artery away from the nerve. RESULTS The neuralgia was promptly relieved after the operation, with no complications. A postoperative magnetic resonance imaging scan showed the basilar artery to be away from the trigeminal root. In a series of 7 patients who underwent this technique of vasculopexy, no arterial complications were noted at short- or long-term follow-up. CONCLUSION Repositioning and vasculopexy of an ectatic basilar artery for the treatment of TGN is safe and effective. This technique can also be used for other neuropathies that result from direct arterial compression.
World Neurosurgery, Apr 1, 2023
Operative Neurosurgery, May 16, 2017
Journal of neurological surgery, Apr 28, 2022
Objective Endoscopic endonasal approaches (EEAs) have shown excellent results for majority of hyp... more Objective Endoscopic endonasal approaches (EEAs) have shown excellent results for majority of hypophyseal tumors. The aim of this study was to evaluate and report the complications of EEA in patients with pituitary adenoma (PA) who underwent surgery between 2013 and 2018. Methods We performed a retrospective review of 310 consecutive patients/325 procedures with PA treated with an EEA from May 2013 to January 2018. Minor complications including transient diabetes insipidus (DI) or new anterior pituitary hormone insufficiency in one axis and major complications including CSF leakage, hematoma needing reoperation, vascular damage, brain infection, new pan-hypopituitarism permanent DI, new visual impairment, neurological deficits, and mortality were recorded. Results We encountered 58 complications in 310 patients (18.7%) and 325 procedures (17.7%). Minor complications were 43 (13.9 and 13.2%) in 310 patients and in 325 procedures, respectively; whereas, major complications were 28 (9 and 8.6%, respectively). Total complications were associated with diameter group 2 (&gt;30 mm), diaphragm sella violation, suprasellar extension, parasellar involvement, nonfunctional secretory type, and intraoperative arachnoid tearing. Conclusion EEA can be considered as a safe surgical treatment which has acceptable complications in the management of PAs.
Journal of neurological surgery, Jun 19, 2020
Background Recently the endoscopic endonasal surgery (EES) has been introduced as a modality for... more Background Recently the endoscopic endonasal surgery (EES) has been introduced as a modality for the treatment of patients with craniopharyngiomas. In this study, we describe our initial experience in treatment of 29 patients with craniopharyngiomas using this approach. Methods Twenty-nine consecutive patients with craniopharyngiomas who had undergone EES in a 5-year period were studied retrospectively. Patients underwent preoperative and postoperative endocrinologic and ophthalmologic evaluations. Radiologic characteristics of tumors and extent of resection were determined. The recurrence and complications were evaluated. Results Pituitary and visual dysfunction were observed preoperatively in 89.7 and 86% of patients, respectively. After EES, visual outcome either showed an improvement or else remained unchanged in 92.3% of the cases; however, pituitary function remained unchanged and even got worsened in 34.6% of the cases. Prevalence of diabetes insipidus before and after surgery was 58.6 and 69.2%. The rate of gross total resection was 62%. Moreover, 86.2% of the tumors were almost totally resected (more than 95% of the tumor size resected). After surgery, cerebrospinal fluid (CSF) leak and meningitis occurred in four (13.8%) and two (6.9%) patients, respectively. Perioperative mortality was seen in two of the cases (6.9%). The mean follow-up was 25 months and tumor recurrence was discovered in four patients (15.3%). Conclusion The EES with the goal of maximal and safe tumor resection could be used for the treatment of most craniopharyngiomas. Although the rates of visual improvement and gross tumor resection are high, CSF leak, pituitary dysfunction, and meningitis are serious concerns.
Pituitary, May 28, 2019
Objective The purpose of the present study is to investigate longitudinal changes in Visual evoke... more Objective The purpose of the present study is to investigate longitudinal changes in Visual evoked potential (VEP) parameters as an objective test after transsphenoidal surgery, its correlation with subjective tests and clinical value of VEP in the prediction of visual outcome. Methods Fifty patients with pituitary macroadenoma who underwent surgical removal of the tumor recruited in this study. All the patients underwent ophthalmic examination, static automated perimetry (SAP), VEP and magnetic resonance imaging (MRI) preoperatively and 3 months after surgery. Results Fifty patients with pituitary macroadenoma (size: 25.1 ± 9.9 mm) were recruited in the study. Before surgery, the pattern of VEP showed a prolonged latency with reduced amplitude in eyes with abnormal visual acuity or abnormal visual field. The P100 wave latencies and amplitudes showed significant correlation with visual acuity and SAP scores. After surgery, visual acuity and visual field improvements were seen in 51% and 65.6% of eyes, respectively. Mean SAP and visual acuity scores increased significantly (p < 0.01), P100 wave latency declined and amplitude improved after surgery but not significantly. The mean age of patients, size of tumors and preoperative P100 wave latency were significantly lower in eyes with visual field and acuity improvement. Conclusion VEP is a helpful quantitative and objective complementary test to visual acuity and SAP exams for assessing pre-operative visual abnormalities and post-operative visual outcome in patients with pituitary macroadenoma.
Anz Journal of Surgery, May 24, 2023
Case reports in clinical practice, Nov 13, 2022
Cavernous sinus hemangiomas (CSHs) are rare, benign, slow-growing neoplasms within the cavernous ... more Cavernous sinus hemangiomas (CSHs) are rare, benign, slow-growing neoplasms within the cavernous sinus. Laterally located to these lesions, the cranial nerves and carotid artery are subject to injury during removal of hemangiomas through a transcranial route. Therefore, forsurgi- cal management of cavernous sinus hemangiomas a medial corridor granted through an endoscop- ic endonasal approach may be less traumatic to the neurovascular bundle. Case-1 describes a 23-year old male who presented with intermittent blurred vision and very mild ptosis on the right side for two yearsbefore admission. Fundoscopic exam, visual acuity and perimetry tests were normal. With intense enhancement after contrastadministration, both brain MRI and CT scan demonstrated an extra-axial mass in the right cavernous sinus. Case-2 presents a 59-year-old male, a known case of renal oncocytoma who underwent nephrec- tomy a year before, with chief complain ofmoderate intermittent headaches. Imaging study of the brain by MRI revealed a sellar mass. Near-total resection for case-1 and gross total resection for case-2 were performed through the an extended endoscopic endonasal approach. We report two cases of near-total and gross total resection of CSHs via an extend- ed endoscopic endonasal approach substantiatingadvances in minimal access neurosurgery to the treatment of such grim lesions of an intricate vicinity of the skull base. At the same time, we focus to review extensively the growing yet heterogenous literature of the past twenty years on the broached topic. The evolution of extended endoscopic endonasal approach over the past two decades changes the dynamism of the surgical practices steeped in tradition and provides a safer alternate route for preserving cranial nerves of this anatomic region.
Archives of Neuroscience, Oct 8, 2017
Background: Pituitary adenomas are the most common space-occupying lesions in the sellar region. ... more Background: Pituitary adenomas are the most common space-occupying lesions in the sellar region. Pituitary adenomas are usually soft, but 5 to 13% of macroadenomas are fibrous. The resection of firm tumors by curettage or suction is challenging. Therefore, preoperative knowledge of the pituitary adenomas consistency could help neurosurgeons plan more appropriate surgical procedures. In this regard, predicting fibrous adenomas by magnetic resonance imaging (MRI) is typically difficult and the results are controversial. We evaluated the correlation of pituitary adenoma consistency during tumor resection with preoperative diffusionweighted images (DWI) findings and apparent diffusion coefficient (ADC) values. Methods: 45 consecutive patients (21 male, 24 female, mean age 43 ± 10) with pituitary macroadenoma were prospectively enrolled. Radiological evaluation with conventional MR and DWI images was done for all patients. Tumor consistency was evaluated at surgery and classified as soft, intermediated, and hard. Histological examination was performed on tumor specimens. Results: Based on the surgical findings, 12 (26.7%) tumors were classified as soft-, 30 (66.6%) as intermediate-, and 3 (6.7%) as hardconsistency macroadenomas. Although the collagen content showed an association with tumor consistency, neither tumor consistency nor collagen content and secretory status were correlated with conventional MRI measures and ADCs in different b values and planes. Conclusions: Preoperative DW MRI was not useful to predict the tumor consistency, collagen content, and hormone-secreting status of pituitary macroadenomas.
Journal of Korean Neurosurgical Society, 2016
respectively. Visual fields were also involved. The profile of pituitary hormones was normal. Com... more respectively. Visual fields were also involved. The profile of pituitary hormones was normal. Computed tomographic scan and magnetic resonance imaging (MRI) showed a well circumscribed, oval mass without calcification, hypointense in T1weighted and isointense in T2-weighted images, in the suprasellar area and the floor of the third ventricle. After the intravenous contrast administration, the mass enhancement was remarkable with the maximum diameter of 32 mm (Fig. 1). CG of the third ventricle and craniopharyngioma were the first and second diagnosis respectively. The patient underwent an expanded endoscopic transnasal transplanum approach. The tumor was retro-chiasmatic and was extended from inferior border of chiasm into third ventricle. Resection of proximal stalk was intended in the pre-operative stage (because of involvement of proximal stalk and infundibulum). It was firm and non-suckable, so it was resected totally by micro-scissors with the aid of angled lens. Fig. 2 depicts intra-operative snapshots of tumor attachments. Dural defect was reconstructed with an overlay fascia lata graft, reinforced with standard nasal septal flap; and lumbar drainage
American Journal of Rhinology & Allergy, Nov 1, 2017
Background: A frontal sinus leak is uncommon and is seen in ϳ15% of cases of patients with cerebr... more Background: A frontal sinus leak is uncommon and is seen in ϳ15% of cases of patients with cerebrospinal fluid (CSF) rhinorrhea. Now, endonasal endoscopic techniques have been reported to reconstruct skull base defects in the frontal sinus with a favorable outcome. Objective: To review our experience in the repair of frontal sinus CSF leaks through an endonasal endoscopic approach. Methods: Twenty-four patients with a frontal sinus leak who underwent endonasal endoscopic repair entered the study. Clinical presentation, location, frontal sinusotomy, graft material, follow-up, and frontal sinus status were evaluated. Results: Among Ͼ100 cases of surgically repaired CSF rhinorrhea, the frontal sinus was the site of the leak in 24 patients (mean age, 28.9 years; mean follow-up, 22 months). The etiology consisted of spontaneous leak and traumatic leak; whereas patients with skull base reconstruction after removal of tumor were excluded. Surgical approaches included Draf IIb, Draf III, Draf IIa in 20, 3, and 1 patients, respectively. Free autografts as two-layer inlay fat-muscle and onlay fascia lata were used in the majority of patients. A success rate was achieved in 95.83% of the patients. Conclusion: Endonasal endoscopic repair of a frontal sinus leak was a successful procedure, with a low failure rate and minimal morbidity.
Clinical Case Reports, Feb 1, 2023
Cephalhematoma is a frequent condition in newborn infants due to birth‐related trauma, but ossifi... more Cephalhematoma is a frequent condition in newborn infants due to birth‐related trauma, but ossified cephalhematoma (OCH) is a rare condition, especially when it presents as a skull lesion in the older pediatric population. Chronic intradiploic hematoma (CIH) is another rare condition caused by an organized hematoma between the inner and outer tables of the skull. Differentiating CIH from OCH could be difficult for young neurosurgeons. We present an 18‐month‐old girl with an OCH presented as a skull lesion, which was managed with craniectomy and en‐bloc excision of the organized hematoma. This manuscript discusses the differences between OCH and CIH in diagnosis and management.
Journal of neurological surgery, Mar 2, 2017
congenitAl encephalocele is defined as a herniation of cranial contents through a cranial defect ... more congenitAl encephalocele is defined as a herniation of cranial contents through a cranial defect in a patient with a medical history negative for secondary causes. 17 Basal encephaloceles are rare, with an estimated incidence of 1 in every 35,000 live births. They are classified into transethmoidal, sphenoorbital, sphenomaxillary, and transsphenoidal. 19 Transsphenoidal encephaloceles are the rarest of the rare, accounting for 5% of basal herniations, and having an estimated incidence of 1 in 700,000 live births. 7 Transsphenoidal encephaloceles have a higher incidence in Southeast Asia than in Western countries. 17 Numerous theories have been proposed to explain the cause of the disease. It has been defined as a multifactorial condition, with a combination of genetic and environmental factors leading to the failure of the neural tube to fuse at the level of the anterior neuropore. 11,19 Neural tissue overgrowth, viral infection, radiation, hyperthermia, hypervitaminosis, salicylates, trypan blue, hypoxia, and numerous other agents have been suggested as causes of persistent openings in the neural tube. 3 Transsphenoidal encephaloceles are usually diagnosed in very young pediatric patients and are commonly as-abbReviations NSF = nasoseptal flap; TMP = titanium mesh plate.
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Papers by Mehdi Zeinalizadeh
Methods: Cases of post-neurosurgical meningitis (with positive CSF culture) were included. After classifying patients as GNB and GPC groups, clinical and paraclinical data were compared.
Results: Out of 2667 neurosurgical patients, CSF culture was positive in 45 patients. 25 (54.3%) were GNB, 19 (41.3%) GPC. The most common microorganisms were Klebsiella pneumoniae (n=14, 31.1%), Coagulase negative staphylococcus (n=8, 17.8%), Staphylococcus aureus (n=6, 13.3%), Acinetobacter baumannii (n=4, 8.9%), Pseudomonas aeruginosa (n=2, 4.4%), and Escherichia coli (n=2, 4.4%). There were no correlation between CSF Leakage, Surgical site appearance, presence of drain, Age and GCS between two groups (P=0.11, P=0.28, P=0.06, P=0.86, P=0.11 respectively). The only different laboratory indexes were ESR (86.8 mm/h vs. 59.5 mm/h, P=0.01) and PCT (13.1 ng/ml vs. 0.8 ng/ml, P=0.02) which were higher in GNB cases. 20% (n=5) of patients with GNB meningitis received preoperative corticosteroid, while none of GPC cases received (P=0.03). The median length of hospitalization for GNB and GPC cases was 56 and 44.4 days respectively (P=0.3).
Conclusion: The GNB antibiotic coverage should be designed more carefully in post-neurosurgical meningitis especially in patients with recent corticosteroid therapy and elevated ESR and procalcitonin.
Methods: Cases of post-neurosurgical meningitis (with positive CSF culture) were included. After classifying patients as GNB and GPC groups, clinical and paraclinical data were compared.
Results: Out of 2667 neurosurgical patients, CSF culture was positive in 45 patients. 25 (54.3%) were GNB, 19 (41.3%) GPC. The most common microorganisms were Klebsiella pneumoniae (n=14, 31.1%), Coagulase negative staphylococcus (n=8, 17.8%), Staphylococcus aureus (n=6, 13.3%), Acinetobacter baumannii (n=4, 8.9%), Pseudomonas aeruginosa (n=2, 4.4%), and Escherichia coli (n=2, 4.4%). There were no correlation between CSF Leakage, Surgical site appearance, presence of drain, Age and GCS between two groups (P=0.11, P=0.28, P=0.06, P=0.86, P=0.11 respectively). The only different laboratory indexes were ESR (86.8 mm/h vs. 59.5 mm/h, P=0.01) and PCT (13.1 ng/ml vs. 0.8 ng/ml, P=0.02) which were higher in GNB cases. 20% (n=5) of patients with GNB meningitis received preoperative corticosteroid, while none of GPC cases received (P=0.03). The median length of hospitalization for GNB and GPC cases was 56 and 44.4 days respectively (P=0.3).
Conclusion: The GNB antibiotic coverage should be designed more carefully in post-neurosurgical meningitis especially in patients with recent corticosteroid therapy and elevated ESR and procalcitonin.