Suprafloccular transhorizontal fissure approach to the cerebellopontine angle: an anatomical study with case series.

The suprafloccular transhorizontal fissure approach is a modified variant of the classical retrosigmoid approach option to be chosen for cerebellopontine angle lesions. In this study, we aimed to demonstrate a previously described but not widely used method, the suprafloccular transhorizontal fissure approach with anatomical dissection on the cadaver, accompanied by a case presentation with the largest clinical series in the literature. Klingler's protocol was used to prepare 8 silicone injected and 8 non-silicone injected human hemispheres. A total of 210 patients who underwent surgery in the cerebellopontine angle between 2019 and 2022 were evaluated in our clinic. Of these, the suprafloccular transhorizontal fissure approach was applied in 33 patient, and it was successful in 26 patient, but this approach could not be achieved in 7 patients. The transhorizontal fissure is a fissure in the cerebellum located between the superior semilunar lobule and the inferior semilunar lobule. In the 26 patients we operated with the suprafloccular transhorizontal fissure approach, there was no need for retraction and no complications developed. However, in 7 patients, this fissure could not be dissected due to adhesions. Suprafloccular approach is an alternative to the classical retrosigmoid approach in tumours smaller than 2 cm, medially localised with little cerebellar oedema and neurovascular compression syndrome. Because in this approach, no cerebellum retraction is required, vascular structures are better preserved and the surgical time is shortened. This approach can be applied in smaller tumours than 2 cm when the sulcal anatomy is appropriate.

Glossopharyngeal neuralgia as initial symptom in combined hyperactive dysfunction syndrome: case report.

OBJECTIVES: Hyperactive dysfunction syndrome (HDS) is defined as symptoms arising from overactivities in cranial nerves, like trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GPN). A combination of these cranial nerve neuralgias, that might or might not occur in one or both sides, either synchronously, or metachronously is called combined hyperactive dysfunction syndrome (CHDS). CASE PRESENTATION: We presented a 73 years-old male patient with CHDS presenting with GPN as the initial symptom, with total relief from GPN, TN, and HFS after microvascular decompression. Up to date, only nine patients have been reported in the literature with symptomatic. CONCLUSIONS: TN-HFS-GPN. Our case is the first case with GPN as the initial symptom. The combination of arterial and venous origin of the offending vessels makes the case picturesage.

Stereotactic Radiosurgery after Subtotal Resection of Critically-Located Grade I Meningioma: A Single-Center Experience and Review of Literature.

AIM: To analyze the results of stereotactic radiosurgery in 295 patients with residual Grade I meningiomas located at parasellar region, petroclival region, cerebellopontine angle and parasagittal region. MATERIAL AND METHODS: A total of 295 patients with Grade 1 residual Meningiomas (197 women, 98 men), who were treated by adjuvant radiosurgery in Gazi University Gamma Knife Center between 2004-2015 were analyzed. WHO Grade 2 and 3 meningiomas were not included in our study. Minimum radiological follow-up was 24 months. The median follow-up was 54 months. The tumor volume, location, treatment dose, morbidity, progression free survival and tumor control rate were analyzed. RESULTS: The median tumor volume was 5.2 cm3 (0.04-39.7), median age was 50 (20-80), median dose was 14 Gy and tumor control rate was 94.5% (stationary in 85.0%, volume reduction in 9.5%). Increase in tumor volume was seen in 16 patients (5.5%) and re-operation was performed in 5 of them (1.6%). Stereotactic radiosurgery was performed again for 8 patients (2.7%).The location of the tumors was as follows: 39.3% parasellar region, 20% cerebellopontine angle, 13.6% petroclival and 27.1% was parasagittal, falcine or convexity. Major morbidities were detected in 6 (2%) patients. Minor morbidities were detected in 18 (6.1%) patients. CONCLUSION: Stereotactic radiosurgery is an effective and safe treatment modality for residual Grade I meningiomas.

Comparison of Thalamus Volume on Magnetic Resonance and Cadaveric Section Images.

AIM: To measure and to compare the volume of thalamus using magnetic resonance imaging (MRI) and the anatomical sections. MATERIAL AND METHODS: In this study, 13 brain specimens were used. First, the images were taken in 3 mm sections on MRI, the thickness of the thalamus was measured. Subsequently, 4 mm coronal sections were prepared using a microtome. The thalamic volumes calculated from cadaveric specimens were compared with the measurements obtained using MRI. RESULTS: On MRI, the mean thalamic volumes on the right and left hemispheres were found to be 5843.4 ± 361.6 mm3 and 5377.0 ± 666.2 mm3 respectively. The mean volumes of the cadaveric sections were 5610.8 ± 401.3 mm3 on the right side and 5618.5 ± 604.1 mm3 on the left hemisphere. No statistically significant difference was found between the volume calculated from MRI and that obtained from the cadaveric section (p < 0.05). CONCLUSION: This study shows a correlation between measurement of thalamus volume based on MRI and those calculated from anatomical sections. Our findings support the reliability of DBS procedures using MRI and stereotactic method.

Two-Dimensional Video of Surgery on Trochlear Schwannoma.

Trochlear schwannoma in the absence of neurofibromatosis is a rare entity.1 These schwannomas originate usually from the intradural cisternal part of the nerve and expand in the ambient and interpeduncular cisterns as well as inferiorly in the upper part of the cerebellopontine cistern.2 This case involves a rare pontomesencephalic lesion removed successfully via the simple retrosigmoid suboccipital route (Video 1). A 49-year-old woman presented to our institute with decreased sensation on the left side of her body for 2 months. Neurologic examination revealed left hemihypoesthesia. Cranial magnetic resonance imaging revealed a lobulated, heterogeneously enhanced cystic tumor within the right ambient cistern compressing the adjacent midbrain and extending to the cerebellopontine angle. After obtaining consent for surgery, the patient underwent a right suboccipital retrosigmoid approach for exploration and resection of the lesion. During the operation, it was determined that the tumor originated from the trochlear nerve. Nerve-sparing surgery was performed with intraoperative neuromonitoring including cranial nerve V, VII, X, XI, and XII electromyography and muscle motor evoked potentials. Gross total resection of the tumor was achieved. In the early postoperative period, the patient's eye movements were normal in all directions. The patient did not have any visual problems and experienced improvement in hemihypoesthesia. She was discharged on the third postoperative day. Pathologic examination confirmed diagnosis of schwannoma. At 2 months after surgery, the patient's eye movements were intact, and trochlear nerve palsy did not occur. The patient gave written informed consent for surgery and publication of this case report.

Can the Etiopathogenesis of Chiari Malformation Be Craniocervical Junction Stabilization Difference? Morphometric Analysis of Craniocervical Junction Ligaments.

OBJECTIVE: The craniocervical junction permits a certain amount of mobility for the cervical spine. The biomechanical properties of occipital bone-atlas joint mainly depend on the bony structure, and atlas-axis joint biomechanical properties mainly depend on ligamentous structure. The underlying etiologic factor of Chiari malformation (CM) is debatable. Nowadays, some researchers argue that stabilization difference is one of the suspicious factors for etiopathogenesis. We aim to analyze the ligamentous morphometric differences of CM. METHODS: Magnetic resonance images of 93 adult healthy subjects (n = 93) without any craniocervical junction development abnormalities and 25 (n = 25) adult patients with craniocervical junction development abnormalities (Arnold CM) were evaluated. Length, width, and length-width ratios of ligaments were evaluated. RESULTS: Length of transverse ligament (mean: 23 ± 3.6 [range: 12.1-31.4]) in the normal population was significantly longer than transverse ligament length in CM patients (mean: 21.3 ± 2.5 [range: 17.2-24.9]). Length of alar ligament (mean: 10.7 ± 2 [range: 5.1-15.4]) in the normal population was significantly longer than alar ligament length in CM patients (mean: 8.8 ± 3.8 [range: 1.1-16.6]) (P = 0.007). CONCLUSIONS: Craniocervical ligaments play an important role in maintaining stability and motion capacity of this region. This study promoted better understanding of craniocervical junction anomalies and provided data that facilitate performing more precise surgical treatment.

Usefulness of End-to-Side Bridging Anastomosis of Sural Nerve to Tibial Nerve: An Experimental Research.

OBJECTIVE: Repair of sensorial nerve defect is an important issue on peripheric nerve surgery. The aim of the present study was to determine the effects of sensory-motor nerve bridging on the denervated dermatomal area, in rats with sensory nerve defects, using a neural cell adhesion molecule (NCAM). METHODS: We compared the efficacy of end-to-side (ETS) coaptation of the tibial nerve for sural nerve defect repair, in 32 Sprague-Dawley rats. Rats were assigned to 1 of 4 groups: group A was the sham operated group, group B rats had sural nerves sectioned and buried in neighboring muscles, group C experienced nerve sectioning and end-to-end (ETE) anastomosis, and group D had sural nerves sectioned and ETS anastomosis was performed using atibial nerve bridge. Neurological evaluation included the skin pinch test and histological evaluation was performed by assessing NCAM expression in nerve terminals. RESULTS: Rats in the denervated group yielded negative results for the skin pinch tests, while animals in the surgical intervention groups (group C and D) demonstrated positive results. As predicted, there were no positively stained skin specimens in the denervated group (group B); however, the surgery groups demonstrated significant staining. NCAM expression was also significantly higher in the surgery groups. However, the mean NCAM values were not significantly different between group C and group D. CONCLUSION: Previous research indicates that ETE nerve repair is the gold standard for peripheral nerve defect repair. However, ETS repair is an effective alternative method in cases of sensorial nerve defect when ETE repair is not possible.

Intrathecal Contrast-Enhanced Magnetic Resonance Imaging-Related Brain Signal Changes: Residual Gadolinium Deposition?

OBJECTIVES: There have been recent studies evaluating brain magnetic resonance imaging changes in patients with normal renal function, after intravenous administration of gadolinium-based contrast agents (GBCAs). Their findings were supported by histological evidence as well and brought a new vision concerning what needs to be learned to provide better patient care. In this report, we aim to present brain magnetic resonance imaging changes after intrathecal administration of a linear ionic agent (gadopentetate dimeglumine). MATERIALS AND METHODS: We evaluated hyperintensities in the deep nuclei of the brain in 6 patients with normal renal function after intrathecal administration of a linear ionic GBCA, without other confounding intravenous GBCA administrations. For visual analysis, T1 signal hyperintensity of the globus pallidus (GP), putamen, pons, and dentate nucleus (DN) were scored on a 4-point scale. For quantitative analysis, using the unenhanced T1-weighted images oval regions of interests were placed within the DN, central pons, GP, and thalamus on different image slice positions. RESULTS: On visual analysis, 5 patients had T1 signal hyperintensity of the DN and GP, whereas the DN/pons signal intensity and the GP/thalamus signal intensity were found to be increased in all 6. CONCLUSIONS: This observation not only adds to our fund of knowledge concerning biodistribution and pharmacokinetics of those agents, but also raises the question of a possible association with the glymphatic pathway.

Effects of Atorvastatin on Experimental Spinal Cord Ischemia-Reperfusion Injury in Rabbits.

AIM: Extent of secondary injury is the determinant of tissue destruction and functional worsening after primary spinal cord injury (SCI). Data have accumulated on alleviation of secondary injury in SCI from many studies on the subject. Besides its cholesterol lowering effects, statins are known to have anti-inflammatory and anti-oxidant effects which are the main targets of spinal cord research. This study aims to evaluate the effects of atorvastatin on experimental spinal cord ischemia-reperfusion injury. MATERIAL AND METHODS: Thirty adult male New Zealand rabbits were allocated into control, ischemia-reperfusion (I/R) and treatment groups. Treatment group received 5 mg/kg of atorvastatin via lavage for the preceding 14 days. Other groups received placebo during the same time period. After two weeks, animals in the I/R and treatment groups underwent abdominal temporary aorta occlusion for 30 minutes. Neurological condition of the animals was recorded during the 48 hours of observation. Afterwards, animals were sacrificed and levels of malondialdehyde, glutathione and nitric oxide in spinal cord tissue and plasma and the histopathological tissue changes were determined. RESULTS: Animals in the treatment groups demonstrated significantly better results than the I/R group regarding biochemical markers. Neurological evaluation using the Tarlov scale demonstrated significantly better results at the 48th hour in treatment group. Histopathological results were also better in the treatment groups. CONCLUSION: Results of this study demonstrate the neuroprotective effects of atorvastatin. Atorvastatin has favorable effects on biochemical markers of oxidative stress in SCI. Further studies with larger cohorts and different time periods are also needed.

A comparison of water-based and land-based core stability exercises in patients with lumbar disc herniation: a pilot study.

PURPOSE: To determine and compare the effects of core stability exercise programs performed in two different environments in lumbar disc herniation (LDH) patients. METHOD: Thirty-one patients who were diagnosed with LDH and were experiencing pain or functional disability for at least 3 months were randomly divided into two groups as land-based exercises or water specific therapy. Also, 15 age-sex-matched healthy individuals were recruited as healthy controls. Both groups underwent an 8-week (3 times/week) core stabilization exercise program. Primary outcomes were pain, trunk muscle static endurance and perceived disability level. The secondary outcome was health-related quality of life. RESULTS: Level of static endurance of trunk muscles was found to be lower in the patients compared to the controls at baseline (p < 0.05). Both treatment groups showed significant improvements in all outcomes (p < 0.05) after 8-week intervention. When two treatment groups were compared, no differences were found in the amount of change after the intervention (p > 0.05). After the treatment, static endurance of trunk muscles of the LDH patients became similar to controls (p > 0.05). CONCLUSION: According to these results, core stabilization exercise training performed on land or in water both could be beneficial in LDH patients and there is no difference between the environments. IMPLICATIONS FOR REHABILITATION: An 8-week core stabilization program performed in water or on land decrease pain level and improve functional status in LDH patients. Both programs seem beneficial to increase health-related quality of life and static endurance of trunk muscles. Core stability exercises could be performed in water as well, no differences were found between methods due to environment.

Results of radiosurgery for trigeminal neuralgia: Ankara experience.

OBJECT: The purpose of this retrospective study is to demonstrate the effectiveness of Gamma Knife radiosurgery for essential trigeminal neuralgia (TGN) and assess the long-term outcome in a cohort from Turkey. METHODS: From 2004 to 2011, 93 cases of essential TGN were treated with single radiosurgery (RS). Female:male ratio was 45:48 and the mean age of the population was 57.06 years. Mean suffering time before treatment was 88.26 months. V2 + V3 was the most effected branch. 38.7% of the cases had no previous invasive procedures. Each case received doses ranging from 70 to 90 Gy in a target located at the pontine trigeminal root entry zone of the trigeminal nerve. Statistical analyses were performed to evaluate the outcome and factors leading to outcome status. RESULTS: The median follow-up period was 28 months. Of the cases 31.2% had poor outcome related to treatment failure after single RS session. The excellent and good outcomes were achieved in 29% and 39.8% of patients, respectively. The probability of maintaining pain relief was calculated as 67% at 36 months and 58% at 72 months. The only complication encountered was facial dysesthesia and was positive in 68.8% of patients. The presence of facial dysesthesia was significantly correlated with better outcomes. In this study, no other factor was determined to have significant influence on outcome. CONCLUSION: RS treatment for TGN is safe and effective. A multicenter, prospective, randomized controlled trial is needed to determine a guideline for better treatment protocols.

Gamma Knife radiosurgery for arteriovenous malformations in pediatric patients.

OBJECTIVE: The authors present the results of Gamma Knife stereotactic radiosurgery performed in a series of children with arteriovenous malformations (AVMs). METHODS: Between June 2005 and January 2014, 75 patients 18 years old or younger received Gamma Knife radiosurgery for AVMs. Of these, 58 patients were eligible for further analysis. The median age of the population was 12 years; 41% presented with hemorrhage, 34% with neurological insult, and 24% patients were diagnosed incidentally. The median AVM volume was 3.5 cm(3). The median radiosurgery-based AVM score (RSBAVMS) was 0.86. The median follow-up period was 32 months. RESULTS: Single session Gamma Knife radiosurgery resulted in complete AVM obliteration in 40 (68.9%) patients. There were 35 (60.3%) excellent outcome (complete obliteration with no new deficits) in this series. During the follow-up period, nine (15.51%) patients experienced new deficits and three (5.1%) patients experienced intracranial hemorrhage. The annual rate of developing new deficits and hemorrhage was calculated as 5.45 and 1.8%, respectively. Volume, gender, RSBAVMS, and nidus type factor were factors associated with excellent outcome. CONCLUSIONS: Radiosurgery was successful in majority of patients with minimal morbidity. Gamma Knife radiosurgery for AVMs can be a safe and successful method in pediatric patients.

Accuracy of pedicle screw placement in thoracolumbar spine with conventional open technique.

AIM: To demonstrate the incidence of screw misplacement and revision rates in a group of 72 patients that underwent pedicle screw fixation for spinal pathologies using the conventional, fluoroscopy-guided open technique. MATERIAL AND METHODS: Data from 72 consecutive patients with spinal instability that received 472 screws between April 2011 and May 2013 were reviewed and pedicle wall breach was graded as mild ( < 3 mm), moderate (3-6 mm) and severe ( > 6 mm). Direction of misplacement was also assessed in reformatted images as medial, lateral, superior and inferior (or in combinations). RESULTS: The indications for pedicle screw placement were as follows: degenerative (59.7%), trauma (13%) and tumor (9.7%). Pedicle screws were inserted between T9 and S1. In this series of the 472 screws, 29 (6.1%) screws were implanted with minimal pedicle wall violation (≤ 3 mm) and 16 screws (3.4%) were implanted with moderate (3-6 mm) violations. There were no severe violations (more than 6 mm) in this series. Pedicle violations were significantly higher in thoracic pedicles and in trauma patients when compared to other groups. Only two patients required pedicle screw repositioning after their index surgery. CONCLUSION: Conventional open technique in pedicle screw placement is a safe and sound method with its low and acceptable complication rates.

Management of brain metastases from non-small cell lung cancer.

PURPOSE: The purpose of the following study is to evaluate the treatment modalities, clinical status and prognostic factors affecting survival rates in patients with newly diagnosed brain metastasis from non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: NSCLC patients with a new diagnosis of one to four brain metastasis evaluated retrospectively for the effects of treatment regimens on local failure-relapse-free survival (LRFS) and overall survival (OS). The relationship between age, gender, performance status, recursive partitioning analysis (RPA) classification, the primary tumor under control, number of metastatic tumors in the brain and total volume of brain metastasis and prognosis is analyzed. RESULTS: Out of a total of 138 (121 male and 17 female) patients, nearly 44.2% received only gamma-knife (GK); 24.6% were received both GK and whole brain radiotherapy (WBRT), 2.9% had GK and surgery, 3.6% received GK, surgery and WBRT, 10.9% had surgery and WBRT and 12.3% received only WBRT for treatment. Median LRFS of surgery plus WBRT group was significantly higher when compared with WBRT group (P<0.0001). The OS was significantly longer for surgery plus WBRT group than the other treatment groups (P=0.037). When median survival of WBRT-only group compared with surgery plus WBRT, it was significantly higher (29.6 months vs. 16.7 months, P=0.006). Median OS of surgery plus WBRT group was significantly higher than GK plus WBRT group (29.6 months vs. 9.3 months, P=0.007). CONCLUSION: WBRT is still the most effective treatment method following surgery in selected patients according to their age, performance status and spread of the primary disease with NSCLC had limited number brain metastasis. Adding WBRT treatment after surgery significantly improved OS and LRFS.

Hyperbaric oxygen in epidural fibrosis: is there a potential for treatment?

AIM: To investigate the effects of hyperbaric oxygen treatment on epidural fibrosis formation in an experimental laminectomy model. MATERIAL AND METHODS: Twenty-four Wistar rats underwent L5-L6 total laminectomy and divided into three groups. Animals in the control group received no further treatment while animals in short and long term groups received 2,5 ATM ABS of hyperbaric oxygen for 3 and 7 days, respectively. The amount of epidural fibrosis was analyzed histologically at the end of 42 days of follow up. RESULTS: The ratio of severe fibrosis was 57% in the control, 29% in the short HBOT, and 14% in the long HBOT groups. Although there was a clear trend towards having less fibrosis in the HBOT groups, the difference did not reach to the level of statistical significance (p=0.242), probably due to small number of animals used in this preliminary study. CONCLUSION: Our findings suggest that hyperbaric oxygen treatment may have favorable effects on epidural fibrosis. Further studies with larger cohorts are required to prove our results.

T2-weighted vs. intrathecal contrast-enhanced MR cisternography in the evaluation of CSF rhinorrhea.

BACKGROUND: Endoscopic surgical approach is being more widely used in the treatment of cerebrospinal fluid (CSF) rhinorrhea. Accurate localization of CSF fistulas prior to surgery is essential in increasing the success of dural repair and in decreasing negative or recurrent explorations. PURPOSE: To evaluate and compare intrathecal contrast medium-enhanced magnetic resonance cisternography (CEMRC) with T2-weighted MR cisternography (T2MRC) in identifying the presence and site of CSF rhinorrhea. MATERIAL AND METHODS: Sixty patients with suspected CSF rhinorrhea underwent MR cisternography including intrathecally enhanced fat-suppressed T1WI in three orthogonal planes and T2WI in the coronal plane. Both set of images were reviewed by two blinded radiologists for the presence and location of CSF leakage. Imaging data were compared with surgical findings and/or beta-2 transferrin testing. RESULTS: With surgery proven CSF leakage in 20 instances as reference, CEMRC detected 18 (90%), whereas T2MRC reported only 13 (65%) correctly. Overall, sensitivity, specificity, positive predictive value, and negative predictive value in detecting CSF fistulas were 92%, 80%, 76%, and 93% for CEMRC, and 56%, 77%, 64%, and 71% for T2MRC, respectively. CONCLUSION: The minimally invasive CEMRC is an effective method with higher sensitivity and specificity than T2MRC in the evaluation of CSF fistulas.

Immunomodulatory effectiveness of azithromycin in prevention of postlaminectomy epidural fibrosis.

OBJECTIVE: One of the important causes of failed back surgery is the extensive peridural fibrosis collecting in the surgical field after spinal surgeries. Today we know that inflammatory mechanisms mediated by the immune system of the body plays an important role in generation of fibrosis. Azithromycin, a macrolide antibiotic, has proven immunomodulatory effects in various diseases. This study aims to investigate the effects of azithromycin on peridural fibrosis. METHODS: Twenty-four Wistar rats received laminectomies before dividing them into three groups randomly. Animals of the control group received normal saline intraperitoneally while animals in the treatment groups received low (20 mg/kg) and high (80 mg/kg) doses of azithromycin intraperitoneally after surgical interventions. The amount of fibrosis, fibroblast density and inflammatory cell density were analyzed histologically. RESULTS: Analysis demonstrated significantly reduced fibrosis, fibroblast density and inflammatory cell density in treatment groups compared to the control group. There was no difference between the treatment groups. CONCLUSION: Immune system plays critical roles in tissue repair and fibrogenesis. Results of our study demonstrated that azithromycin application reduced formation of peridural fibrosis in experimental laminectomy model in rats. Further studies with different dose regimes and different application routes are required to carry these results to an advanced level.