Neuroprotective Effects of Niacin on Ischemia/Reperfusion Injury of the Rabbit Spinal Cord.

OBJECTIVE: Previous studies have shown niacin has neuroprotective effects on the central nervous system. However, its specific effect on spinal cord ischemia/reperfusion injury has not yet been explored. This study aims to evaluate whether niacin can contribute neuroprotective effects on spinal cord ischemia/reperfusion injury. METHODS: Rabbits were randomized into 4 groups of 8 animals: group I (control), group II (ischemia), group III (30 mg/kg methylprednisolone, intraperitoneal), and group IV (500 mg/kg niacin, intraperitoneal). The rabbits in group IV were premedicated with niacin for 7 days prior to inducing ischemia/reperfusion injury. The control group was subjected only to a laparotomy, while the remaining groups underwent spinal cord ischemia through a 20-minute occlusion of the aorta caudal to the left renal artery. Following the procedure, levels of catalase, malondialdehyde, xanthine oxidase, myeloperoxidase, and caspase-3 were analyzed. Ultrastructural, histopathological, and neurological evaluations were also performed. RESULTS: Spinal cord ischemia/reperfusion injury resulted in increased levels of xanthine oxidase, malondialdehyde, myeloperoxidase, and caspase-3, with a concomitant decrease in catalase levels. Treatment with methylprednisolone and niacin led to decreased levels of xanthine oxidase, malondialdehyde, myeloperoxidase, and caspase-3 and an increase in catalase. Both methylprednisolone and niacin treatments demonstrated improvements in histopathological, ultrastructural, and neurological assessments. CONCLUSIONS: Our findings suggest that niacin has antiapoptotic, anti-inflammatory, antioxidant, and neuroprotective effects at least equal to methylprednisolone in ischemia/reperfusion injury of the spinal cord. This study is the first to report the neuroprotective impact of niacin on spinal cord ischemia/reperfusion injury. Further research is warranted to elucidate the role of niacin in this context.

Metastatic diffuse follicular variant papillary thyroid cancer without cervical lymph node metastasis presenting with symptoms related to hypopituitarism.

In this article, we present a case of diffuse follicular variant papillary thyroid carcinoma with pituitary metastasis, which is a rare cause of pituitary metastasis. The follicular variant of papillary thyroid carcinoma is an uncommon variant of papillary carcinoma. A 74-year-old male was presented with weakness, fatigue, and a decreased appetite. The patient was diagnosed with secondary adrenal and thyroid insufficiencies. Imaging revealed a pituitary mass with suprasellar extension, right cavernous sinus invasion, and optic chiasm compression. Thyroid ultrasonography revealed a nodule with a maximum size of 7.2cm in the right lobe. Cytological examination via fine-needle aspiration suggested papillary thyroid cancer. Total thyroidectomy with central and right lateral neck dissection confirmed the diagnosis of diffuse follicular variant of papillary thyroid carcinoma. Owing to visual field defects, the patient underwent transsphenoidal surgery. Histological and immunohistochemical evaluations confirmed pituitary metastasis from the papillary thyroid cancer. Radioactive iodine treatment and gamma knife radiotherapy of the pituitary gland were performed. The initiation of sorafenib treatment was deemed appropriate during the follow-up. A significant decrease in the thyroglobulin levels was observed after sorafenib treatment. Pituitary metastasis should be considered in patients diagnosed with hypopituitarism and pituitary lesions at initial evaluation. The presence of visual field defects may be an indication for neurosurgical intervention and guide both diagnosis and treatment. The management of papillary thyroid cancer and the role of treatment modalities in prognosis depend on the biological behavior of the tumor. Early diagnosis and multidisciplinary management are crucial for the treatment of these patients.

Cerebrolysin Amelioration of Spinal Cord Ischemia/ Reperfusion Injury in Rabbit Model.

AIM: To investigate the effects of cerebrolysin on inflammation, oxidative stress, apoptosis, and neurologic recovery in the setting of an experimental rabbit model of spinal cord ischemia/reperfusion injury (SCIRI). MATERIAL AND METHODS: Rabbits were randomly divided into five groups: control, ischemia, vehicle, methylprednisolone (30 mg/kg), and cerebrolysin (5 ml/kg) group. The rabbits in the control group underwent only laparotomy; the other groups underwent spinal cord ischemia and reperfusion injury for 20 minutes. Neurologic examination after 24 hours was based on the Modified Tarlov scale. Myeloperoxidase activities, catalase and malondialdehyde levels, and caspase-3 concentrations were determined in serum and tissue samples. Serum xanthine oxidase levels were studied and histopathological and ultrastructural changes were examined. RESULTS: After SCIRI, serum and tissue myeloperoxidase activities, malondialdehyde levels, caspase-3 concentrations, and serum xanthine oxidase activities were increased (p < 0.01?0.001). Catalase levels were significantly diminished (p < 0.001). Cerebrolysin treatment correlated with reduced myeloperoxidase and xanthine oxidase activities, malondialdehyde levels and caspase-3 concentrations; and with increased catalase levels (p < 0.001, for all). The cerebrolysin group showed improved histopathological, ultrastructural, and neurological outcomes. CONCLUSION: For the first time in the literature, the current study reports anti-inflammatory, antioxidant, antiapoptotic, and neuroprotective effects of cerebrolysin in a SCIRI rabbit model.

Mildronate Has Ameliorative Effects on the Experimental Ischemia/Reperfusion Injury Model in the Rabbit Spinal Cord.

BACKGROUND: Mildronate is a useful anti-ischemic agent and has antiinflammatory, antioxidant, and neuroprotective activities. The aim of this study is to investigate the potential neuroprotective effects of mildronate in the experimental rabbit spinal cord ischemia/reperfusion injury (SCIRI) model. METHODS: Rabbits were randomized into 5 groups of 8 animals as groups 1 (control), 2 (ischemia), 3 (vehicle), 4 (30 mg/kg methylprednisolone [MP]), and 5 (100 mg/kg mildronate). The control group underwent only laparotomy. The other groups have the spinal cord ischemia model by a 20-minute aortic occlusion just caudal to the renal artery. The malondialdehyde and catalase levels and caspase-3, myeloperoxidase, and xanthine oxidase activities were investigated. Neurologic, histopathologic, and ultrastructural evaluations were also performed. RESULTS: The serum and tissue myeloperoxidase, malondialdehyde, and caspase-3 values of the ischemia and vehicle groups were statistically significantly higher than those of the MP and mildronate groups (P < 0.001). Serum and tissue catalase values of the ischemia and vehicle groups were statistically significantly lower than those of the control, MP, and mildronate groups (P < 0.001). The histopathologic evaluation showed a statistically significantly lower score in the mildronate and MP groups than in the ischemia and vehicle groups (P < 0.001). The modified Tarlov scores of the ischemia and vehicle groups were statistically significantly lower than those of the control, MP, and mildronate groups (P < 0.001). CONCLUSIONS: This study presented the antiinflammatory, antioxidant, antiapoptotic, and neuroprotective effects of mildronate on SCIRI. Future studies will elucidate its possible use in clinical settings in SCIRI.

Endonasal endoscopic approach for sellar metastatic pathologies: a national observation.

PURPOSE: Sellar metastases are rare lesions. Recent improvements in diagnosis and treatment strategies have prolonged survival but increased the probability of metastatic tumors. Evaluation with clinical symptomatology and meticulous laboratory examination is crucial. We present our multicenter national study on sellar metastases to evaluate and underline the main clinical, endocrine, and radiological considerations regarding the diagnosis and endonasal endoscopic management of such rare lesions. METHODS: A medical literature-based retrospective study was planned across 13 neurosurgical centers in Turkey, where a data survey was conducted to collect information regarding sellar metastases surgically treated using the endoscopic endonasal approach, including clinical presentation, radiographic features, primary tumor origin, histopathological confirmation, time to metastasis, treatment, and patient outcomes. RESULTS: Between 2010 and 2020, 54 patients (22 women [40.7%] and 32 men [59.3%]) who underwent surgery with the endonasal endoscopic approach and had pathologically proven sellar metastases (overall incidence, 0.54%) were included. Of the patients, 59.3% had no known malignancy and presented with new-onset symptoms, 79.6% reported headache, 51.9% complained of some degree of visual deficits, and 50% had cranial nerve symptoms. Tissue biopsy was performed in 7.4% of the patients, whereas gross or subtotal resection was achieved in the remaining patients. CONCLUSION: To our knowledge, this is the largest series of patients surgically treated with the endonasal endoscopic approach for sellar metastases. For these patients, the treatment focus should be on management modalities for increasing quality of life instead radical treatment options with survival benefit.

Metastatic diffuse follicular variant papillary thyroid cancer without cervical lymph node metastasis presenting with symptoms related to hypopituitarism

ABSTRACT In this article, we present a case of diffuse follicular variant papillary thyroid carcinoma with pituitary metastasis, which is a rare cause of pituitary metastasis. The follicular variant of papillary thyroid carcinoma is an uncommon variant of papillary carcinoma. A 74-year-old male was presented with weakness, fatigue, and a decreased appetite. The patient was diagnosed with secondary adrenal and thyroid insufficiencies. Imaging revealed a pituitary mass with suprasellar extension, right cavernous sinus invasion, and optic chiasm compression. Thyroid ultrasonography revealed a nodule with a maximum size of 7.2cm in the right lobe. Cytological examination via fine-needle aspiration suggested papillary thyroid cancer. Total thyroidectomy with central and right lateral neck dissection confirmed the diagnosis of diffuse follicular variant of papillary thyroid carcinoma. Owing to visual field defects, the patient underwent transsphenoidal surgery. Histological and immunohistochemical evaluations confirmed pituitary metastasis from the papillary thyroid cancer. Radioactive iodine treatment and gamma knife radiotherapy of the pituitary gland were performed. The initiation of sorafenib treatment was deemed appropriate during the follow-up. A significant decrease in the thyroglobulin levels was observed after sorafenib treatment. Pituitary metastasis should be considered in patients diagnosed with hypopituitarism and pituitary lesions at initial evaluation. The presence of visual field defects may be an indication for neurosurgical intervention and guide both diagnosis and treatment. The management of papillary thyroid cancer and the role of treatment modalities in prognosis depend on the biological behavior of the tumor. Early diagnosis and multidisciplinary management are crucial for the treatment of these patients.

Neuroprotective Effects of Dexpanthenol on Rabbit Spinal Cord Ischemia/Reperfusion Injury Model.

OBJECTIVE: Dexpanthenol (DXP) reportedly protects tissues against oxidative damage in various inflammation models. This study aimed to evaluate its effects on oxidative stress, inflammation, apoptosis, and neurological recovery in an experimental rabbit spinal cord ischemia/reperfusion injury (SCIRI) model. METHODS: Rabbits were randomized into 5 groups of 8 animals each: group 1 (control), group 2 (ischemia), group 3 (vehicle), group 4 (methylprednisolone, 30 mg/kg), and group 5 (DXP, 500 mg/kg). The control group underwent laparotomy only, whereas other groups were subjected to spinal cord ischemia by aortic occlusion (just caudal to the 2 renal arteries) for 20 min. After 24 h, a modified Tarlov scale was employed to record neurological examination results. Malondialdehyde and caspase-3 levels and catalase and myeloperoxidase activities were analyzed in tissue and serum samples. Xanthine oxidase activity was measured in the serum. Histopathological and ultrastructural evaluations were also performed in the spinal cord. RESULTS: After SCIRI, serum and tissue malondialdehyde and caspase-3 levels and myeloperoxidase and serum xanthine oxidase activities were increased (P < 0.05-0.001). However, serum and tissue catalase activity decreased significantly (P < 0.001). DXP treatment was associated with lower malondialdehyde and caspase-3 levels and reduced myeloperoxidase and xanthine oxidase activities but increased catalase activity (P < 0.05-0.001). Furthermore, DXP was associated with better histopathological, ultrastructural, and neurological outcome scores. CONCLUSIONS: This study was the first to evaluate antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects of DXP on SCIRI. Further experimental and clinical investigations are warranted to confirm that DXP can be administered to treat SCIRI.

The Overlap in Neuroimaging Findings Between Idiopathic Normal Pressure Hydrocephalus and Progressive Supranuclear Palsy.

Background: The neuroimaging findings of brain stem atrophy resembling progressive supranuclear palsy (PSP) radiology are common in idiopathic normal pressure hydrocephalus (iNPH) subjects. Besides, recent studies report the existence of iNPH-like MRI findings in PSP subjects. We aimed to comparatively investigate the neuroimaging indices of iNPH and PSP in our patient groups in a detailed methodology. Methods: Ultimately, 19 probable PSP patients and 18 patients with a definite diagnosis of iNPH were enrolled. The subjects were recruited retrospectively from those who had been admitted between 2017 and 2021 to the Movement Disorders Polyclinic and the Neurosurgery Clinic of the Diskapi Yildirim Beyazit Training and Education Hospital. MRI-based DESH score, Evans index, and the callosal angle (CA) have been calculated in all the individuals. Besides, quantitative MRI parameters of PSP were evaluated in every subject. Statistical analyses were performed using IBM SPSS Statistics 26. Results: The comparative analyses regarding the radiological parameters of PSP did not reveal any difference between patient groups. On the other hand, the comparisons of the neuroimaging parameters of iNPH, yielded differences in the CA, CA score, and the total DESH score. However, the ROC curve analyses did not reveal a discriminative power at a value of "very good" or "excellent" in any of the indices. Conclusions: We found that the neuroimaging features of iNPH and PSP highly overlapped between these patient groups. These results may provide indirect evidence regarding the coexistence of PSP and iNPH pathophysiology that has been deliberated in several recent reports.

Effect of Preoperative Serum Transthyretin Levels on Postoperative Clinical Results and Morbidity in Patients Undergoing Spinal Surgery.

INTRODUCTION: This study aims to investigate the effects of preoperative serum transthyretin (TTR) levels on surgical success, pain scores, and postoperative morbidity. METHODS: Note that, in our clinic, 188 patients who were operated for spinal pathologies between June 2010 and January 2011 were included in this study. Blood samples were drawn from all patients on the morning of surgery, and then, serum TTR measurements were made. Demographic data of all patients were collected, and then their preoperative and postoperative neurological examinations, Karnofsky scores, Visual Analog Scale (VAS) scores, Oswestry disability index (ODI) scores, postoperative infection and wound healing status, hospital stay, and morbidity levels were recorded, and TTR levels were compared. RESULTS: When preoperative TTR level of patients was low, their Karnofsky scores decreased, ODI scores increased, the early postoperative VAS and late postoperative VAS values increased, and the length of hospital stay was increased. Moreover, in patients with low TTR levels, postoperative Karnofsky scores were lower, postoperative ODI levels were higher, postoperative early and late VAS scores were higher, hospital stays were longer, peroperative complication rates were higher, wound infection rates were higher, the delay in wound site healing was higher, and the morbidity rate was higher. CONCLUSION: Consequently, preoperative low TTR levels have been reported to be an effective parameter that can be used to predict surgical results, wound infection and wound site healing status, perioperative complications, and morbidity in spinal surgery.

Amelioration of Cerebral Vasospasm and Secondary Injury by Vigabatrin After Experimental Subarachnoid Hemorrhage in the Rabbit.

BACKGROUND: Vigabatrin, an antiepileptic drug, increases the level of gamma aminobutyric acid in the brain by inhibiting its catabolism. Because gamma aminobutyric acid has been proved to have vasodilatory effects, in the present study, we investigated the effect of vigabatrin to treat experimental subarachnoid hemorrhage (SAH)-induced vasospasm. METHODS: A total of 30 New Zealand white rabbits were divided into 3 groups of 10 each: the control group, SAH group, and vigabatrin group. Experimental SAH was established by injection of autologous arterial blood into the cisterna magna. In the vigabatrin group, the rabbits were administered vigabatrin for 3 days after induction of the SAH. The first dose of vigabatrin was given 2 hours after SAH induction. A daily dose of 500 mg/kg vigabatrin was administered intraperitoneally. After 3 days, the rabbits were sacrificed, and the brains were removed, together with the cerebellum and brainstem. The basilar artery wall thickness and lumen areas were measured. The neuronal degeneration in the hippocampus (CA1, CA3, and dentate gyrus) was also evaluated. RESULTS: The arterial wall thickness of the vigabatrin group was less than that in the SAH group (P < 0.001), and the mean luminal area of the vigabatrin group was greater than that in the SAH group (P < 0.001). Additionally, the hippocampal neuronal degeneration score of the vigabatrin group was lower than that of the SAH group (P < 0.001). CONCLUSION: These findings have indicated that vigabatrin has a vasodilatory effect in an experimental SAH model in the rabbit. Moreover, it showed a neuroprotective effect in the hippocampal neurons against secondary injury induced by SAH.

The Vasorelaxant and Neuroprotective Effects of Mildronate in A Rabbit Subarachnoid Hemorrhage Model.

AIM: To investigate the effects of an anti-ischemic agent, mildronate, on subarachnoid hemorrhage-induced vasospasm. MATERIAL AND METHODS: Rabbits were randomly divided into four groups: control, subarachnoid hemorrhage (SAH), vehicle, and mildronate (n=8 animals per group). In the treatment group, 200 mg/kg of mildronate were intraperitoneally administered 5 minutes after the procedure and continued for 3 days as daily administrations of the same dose. At the end of the third day, the cerebrum, cerebellum, and brain stem were perfused, fixated, and removed for histopathological examination. Tissues were examined for arterial wall thickness, luminal area, and hippocampal neuronal degeneration. RESULTS: Mildronate group showed significantly increased luminal area and reduced wall thickness of the basilar artery compared with the subarachnoid hemorrhage group. In addition, the hippocampal cell degeneration score was significantly lower in the mildronate group than in the SAH and vehicle groups. CONCLUSION: These results show that mildronate exerts protective effects against SAH-induced vasospasm and secondary neural injury.

The effects of Cinnamaldehyde on early brain injury and cerebral vasospasm following experimental subarachnoid hemorrhage in rabbits.

The neuroprotective and vasodilatory effects of cinnamaldehyde have been widely studied and documented. On the basis of these findings, we hypothesized that cinnamaldehyde exhibits therapeutic effects on subarachnoid hemorrhage-induced early brain injury and cerebral vasospasm. Thirty-two adult male New Zealand white rabbits were randomly divided into four groups of eight rabbits: control, subarachnoid hemorrhage, subarachnoid hemorrhage + vehicle, and subarachnoid hemorrhage + cinnamaldehyde. An intraperitoneal dose of 50 mg/kg cinnamaldehyde was administered 5 min following an intracisternal blood injection, followed by three further daily injections at identical doses. The animals were sacrificed 72 h after subarachnoid hemorrhage was induced. The cross-sectional areas and arterial wall thicknesses of the basilar artery were measured and hippocampal degeneration scores were evaluated. Treatment with cinnamaldehyde was effective in providing neuroprotection and attenuating cerebral vasospasm after subarachnoid hemorrhage in rabbits. It effectively increased the cross-sectional areas of the basilar artery and reduced the arterial wall thickness; in addition, hippocampal degeneration scores were lower in the cinnamaldehyde group. The findings of this study showed, for the first time to our knowledge, that cinnamaldehyde exhibits neuroprotective activity against subarachnoid hemorrhage-induced early brain injury and that it can prevent vasospasm. Potential mechanisms underlying the neuroprotection and vasodilation were discussed. Cinnamaldehyde could play a role in subarachnoid hemorrhage treatment.

Modified Inside-outside Occipito-Cervical Plate System: Preliminary Results.

CONTEXT: Internal rigid fixation provides immediate stability of the occipito-cervical (OC) junction for treatment of instability; however, in current practice, the optimal OC junction stabilization method is debatable. AIMS: The aim of this study to test the safety and efficacy of a newly designed modified inside-outside occipito-cervical (MIOOC) plate system for the treatment of instability. SETTINGS AND DESIGN: This was a feasibility study of MIOCC plate system. SUBJECTS AND METHODS: Five male and four female patients with OC instability were treated using MIOOC plate system. Stabilization rate, safety, and efficacy were evaluated radiologically and clinically. RESULTS: Mean age of the patients was 35 ± 11 (range: 22-58) years. Etiology of OC instability included trauma, neoplasm, congenital abnormalities, and iatrogenic. The fusion levels ranged from occiput-C3 to occiput-C6. Mean follow-up duration was 22 ± 10 (range: 6-46) months. There were neither complication nor was there any need for plate revision or screw pullout. Mortality occurred in one patient due to primary malignancy at 6 months; otherwise, no morbidity was observed. During the follow-up, no recurrent subluxation or newly developed instability at adjacent levels occurred. All patients showed a satisfactory union at the most recent follow-up examination. CONCLUSIONS: These preliminary results suggest that the MIOCC plate system is a useful and safe method for providing immediate internal stability of the OC junction. Using a multi-piece plate design in this plate system provided easy implantation and a better interface between plate and OC bones. Further, clinical studies and long-term results are needed to determine the reliability of the MIOOC plate system.