Correlations Among Consistency, Computed Tomography Values, and Histopathological Subtypes of Spinal Meningioma.

The consistency of spinal meningiomas is important to consider when performing tumor removal surgery. This study evaluated the correlations between spinal meningioma consistency and both preoperative computed tomography (CT) values and histopathological subtypes. Fifteen consecutive patients who underwent surgical resection of spinal meningioma at our institution were identified, and preoperative CT values and the signal intensity of T2-weighted magnetic resonance images of the tumor were determined retrospectively. The consistency of the spinal meningioma was defined based on the ultrasonic surgical aspirator output during tumor debulking. Patients were assigned to 2 groups: a soft group (n=4) and a hard group (n=11). The T2 signal intensity was significantly higher in the soft group than in the hard group (p=0.001). While the CT values were considerably higher in the hard group, the difference was not significant (p=0.19). Regarding the histopathological subtypes, psammomatous meningioma exhibited significantly higher CT values than meningothelial meningioma (p=0.019); however, there was a higher frequency of hard tumors in meningothelial meningioma cases than in psammomatous meningioma cases. Although neither robust correlations between tumor consistency and CT values nor a relationship between tumor consistency and histopathological subtype has been established, these results might help with the perioperative manegement of spinal tumors.

Calcified ectopic TSH-secreting pituitary adenoma mimicking craniopharyngioma: a rare case report and literature review.

Among pituitary adenomas, which are relatively common brain tumors, elements of ectopic, thyroid-stimulating hormone (TSH) secretion, and intratumoral calcification are unusual. Here, we present an extremely rare case of a calcified ectopic TSH-secreting pituitary adenoma arising from the pars tuberalis mimicking craniopharyngioma based on neuroimaging findings. To our knowledge, this is the first case report of calcified ectopic TSH-secreting pituitary adenoma without symptoms of excessive thyroid hormone secretion.

Surgery for ventral intradural thoracic spinal tumors with a posterolateral transpedicular approach.

BACKGROUND: Surgery for ventrally seated thoracic tumors requires an anatomically specific approach that is distinct from cervical or lumbar spinal cord surgery as the narrower spinal canal of the thoracic spinal cord makes it sensitive to surgical procedures. However, reports describing this operative technique are few. To obtain a wide operative field and minimize thoracic spinal cord retraction, we employed a posterolateral transpedicular approach in ventral-located tumors and investigated the efficacy and limitations of this technique. METHOD: Eighteen patients with lesions (meningioma or neurinoma) located in the ventral intradural thoracic region were surgically treated between 2009 and 2014. The relationship among the clinical outcome, tumor location, and postoperative spinal alignment was analyzed. RESULTS: Postoperative neurological function improved in all patients, namely those with meningioma (p = 0.012) and schwannoma (p = 0.018). One patient who underwent removal of two facet joints suffered a postoperative compression fracture. Removal of two facet joints and pedicles resulted in a worsening of spinal alignment (p = 0.03), while this was not the case for the removal of one facet joint and pedicle (p = 0.72). CONCLUSIONS: This case series clarified the benefits of the posterolateral transpedicular approach for resection of ventral intradural extramedullary tumors. Removal of one pedicle and facet joint seems to be more beneficial.

Usefulness of a device for body support during operations performed while standing.

During microsurgical procedures, manipulations are often performed using a foot switch while the surgeon stands on one foot. This position can easily result in body axis instability and greater musculoskeletal loading. To support the surgeon's posture, we have developed a tool called the "Surgeon's Body Support Device." The objective of this study was to determine the efficacy of this device by analyzing surgeons' kinematics and musculoskeletal loading during simulated operations undertaken while standing. Fourteen surgeons volunteered to perform simulations of surgery while standing. To analyze motion kinetics and musculoskeletal loading with and without this device, a three-axis accelerometer and surface electromyography (SEMG) sensors were attached to the subjects. Compared with not using the supportive device, the axis of the surgeon's body was significantly more stable when the support device was used (P = .001). The evenness of motion also tended to be superior when the device was utilized (P = .009). Simulations performed using the device significantly reduced the musculoskeletal loading on the ventral side of the left foot by 70 % compared with simulations performed not using the device (P = .001). Data from SEMG sensor placed on the right hand, which performs the surgical manipulations, indicated that simulations performed using the device generated approximately 10 % of the musculoskeletal load generated when the device was not used (P = .001). The Surgeon's Body Support Device appears to improve maneuverability and reduce musculoskeletal loading during simulated surgical procedures undertaken while standing.

Proposed imaging assessment score for aneurysmal subarachnoid hemorrhage correlated with prognosis: Shinshu Aneurysmal subarachnoid hemorrhage score.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (aSAH) imaging has been shown to correlate with prognosis. However, no numerical index of bleeding severity has been established. This study aimed to propose a new simple scoring system for computed tomography imaging of aSAH and to confirm its effectiveness in retrospective and prospective studies. METHODS: We devised an image evaluation system as an objective index. This system was established by scoring six items, with a maximum total of 19 points. Using this score, named the Shinshu Aneurysmal Subarachnoid Hemorrhage Score (S-score), we performed a retrospective study of 210 patients with aSAH at a single institution to confirm its efficacy. Age and World Federation of Neurosurgical Societies grades were adopted as other verification items, and the modified Rankin Scale was used for prognostic evaluation. A multicenter prospective study was then conducted to examine the function of the score by examining 214 patients with aSAH. RESULTS: In the retrospective study, the threshold of the S-score between good and poor prognoses was 9/19 points. The area under the curve by receiver operating characteristic analysis of the S-score was 0.819, suggesting efficacy, with an odds ratio (OR) of 1.291 (1.077-1.547). In the prospective study, the judgment capability of the S-score was evaluated with a sensitivity of 0.674, specificity of 0.881, positive predictive value of 0.789, negative predictive value of 0.804, false-positive ratio of 0.119, false-negative ratio of 0.325, positive likelihood ratio of 6.072, and negative likelihood ratio of 1.369. S-score showed a significant difference in prognosis. The OR was 1.183 (1.009-1.388). CONCLUSIONS: The scoring system could contribute to patient prognosis assessment. S-score and its prognostic formulas may serve as an objective source of information in the development of clinical medicine.

Single-lane clipping technique for a ruptured aneurysm of A1 fenestration of the anterior cerebral artery: a case report and literature review.

Fenestration of the A1 segment of the anterior cerebral artery is a rare vascular anomaly with a high risk of saccular aneurysm at the proximal end of the A1 fenestration. These aneurysms have a high risk of rupture. However, conventional surgical clipping can be technically challenging due to the anatomical characteristics. We report a case of A1 fenestration with a ruptured aneurysm wherein we successfully achieved complete obliteration of the aneurysm with a new "single-lane" clipping technique. A 64-year-old woman presented with a ruptured saccular A1 aneurysm at the proximal end of an A1 fenestration, resulting in subarachnoid hemorrhage. Microsurgical clipping was attempted; however, adequate exposure of the aneurysm could not be achieved. The recurrent artery of Heubner originated near the distal end of the lateral limb of the A1 fenestration. The lateral limb of the A1 fenestration had no perforating arteries, according to surgical examination. Thus, the aneurysm neck and lateral limb were concurrently obliterated using a nonfenestrated clip, preserving the medial limb of the A1 fenestration. The antegrade flow of the recurrent artery of Heubner was detected using the retrograde flow of the distal part of the lateral limb of the A1 fenestration during intraoperative indocyanine green video angiography. The postoperative course was uneventful without any evidence of ischemic stroke. For A1 aneurysms arising from the proximal end of the A1 fenestration, this technique may be a useful treatment option. Before using this technique, careful surgical exploration should be performed to assess the A1 perforating arteries.

Local brain herniation after partial membranectomy for organized chronic subdural hematoma in an adult patient: case report and review of the literature.

OBJECTIVE: Local brain herniation after removal of chronic subdural haematoma is extremely rare, especially in adult patients. This study reports a case of local brain herniation after partial membranectomy for organized chronic subdural haematoma. CASE REPORT: A 77-year-old man presented with dysarthria and dysphasia caused by local brain herniation of the right frontal lobe through a defect of the inner membrane. The herniated brain was detected by magnetic resonance (MR) imaging. The patient underwent a craniotomy to release the herniated and strangulated brain, which were consistent with the MR imaging findings. The patient recovered fully within 1 month after surgery. CONCLUSIONS: To date, five cases of brain herniation through the internal subdural membrane have been reported as complications of chronic subdural haematomas. All but one case occurred in the paediatric population. Urgent surgery should be performed, even if an adult patient suffers from local brain herniation, for preservation of brain function. This is the sixth reported case of brain herniation through a defect of the inner membrane and the second reported case in the adult population.

Anatomical study of the trigeminal and facial cranial nerves with the aid of 3.0-tesla magnetic resonance imaging.

OBJECT: Neuroimages often reveal that the trigeminal or facial nerve comes in contact with vessels but does not produce symptoms of trigeminal neuralgia (TN) or hemifacial spasm (HFS). The authors conducted this study to determine how often the trigeminal and facial nerves came in contact with vessels in individuals not suffering from TN or HFS. They also investigated the correlation between aging and the anatomical measurements of the trigeminal and facial nerves. METHODS: Between November 2005 and August 2006, 220 nerves in 110 individuals (60 women and 50 men; mean age 55.1 years, range 19-85 years) who had undergone brain magnetic resonance (MR) imaging for other reasons were studied. The lengths, angles, ratio, and contact points were measured in each individual. A correlation between each parameter and age was statistically analyzed. RESULTS: The mean (+/- standard deviation) length of the trigeminal nerve was 9.66 +/- 1.71 mm, the mean distance between the bilateral trigeminal nerves was 31.97 +/- 1.82 mm, and the mean angle between the trigeminal nerve and the midline was 9.71 +/- 5.83 degrees . The trigeminal nerve was significantly longer in older patients. Of 220 trigeminal nerves, 108 (49.0%; 51 women and 57 men) came in contact with vasculature. There was 1 contact point in 99 nerves (45%) and 2 contact points in 9 nerves (4.1%). Contact without deviation of the nerve was seen in 91 individuals (43 women and 48 men), and mild deviation was noted in 17 individuals (8 women and 9 men). There was no moderate or severe deviation in any individual in this series. The mean length of the facial nerve was 29.78 +/- 2.31 mm, the mean distance between the bilateral facial nerves was 28.65 +/- 2.22 mm, the angle between the nerve and midline was 69.68 +/- 5.84 degrees , and the vertical ratio at the porus acusticus was 0.467 +/- 0.169. Of all facial nerves, 173 (78.6%; 101 in women and 72 in men) came in contact with some vasculature. Contact without deviation was seen on 64 sides (in 37 women and 27 men), mild deviation on 98 sides (in 57 women and 41 men), and moderate deviation on 11 sides (in 7 women and 4 men). There was no severe deviation of the facial nerve in this series. The proximal length of the facial nerve, interval, angle, and ratio against the age were significantly shorter or smaller in the older individuals. CONCLUSIONS: The findings in asymptomatic individuals in this study will help in deciding which findings observed on MR images may cause symptoms. In addition, the authors describe the variations of normal anatomy in older individuals. Knowledge of the normal anatomy helps to hone the diagnostic practices for microvascular decompression, which may increase the feasible results on such surgery.

Description and first clinical application of AirWay Scope for tracheal intubation.

We have developed a novel airway apparatus, AirWay Scope, which we have used in the orotracheal intubation of 10 consecutive patients requiring general anesthesia before neurosurgical procedures. The characteristic shape of the introducer (INTLOCK), the tube guiding function and the sighting device of the AirWay Scope has possibility to facilitate tracheal intubation. Here, we report the first clinical application of this system and describe potential advantages of the apparatus.

Long Segment Spinal Dural Cyst: A Case Report.

BACKGROUND: Spinal meningeal cysts are a rare benign disease that can cause myelopathy. In most cases, spinal meningeal cysts consist of an arachnoid membrane. To the best of our knowledge, few articles have report on intradural spinal meningeal cyst consisting of dura mater. CASE DESCRIPTION: A 58-year-old man presented to our institute with aggravation of clumsy hands and dysesthesia of the feet. Magnetic resonance imaging of the entire spine revealed a cystic lesion compressing the spinal cord posteriorly. Cyst fenestration and placement of the cyst-subarachnoid shunt was performed via an anterior approach. Postoperatively, the histopathologic results revealed that the cyst wall consisted of a dura mater-like membrane. The patient's symptoms resolved without the appearance of any new neurologic deficits. CONCLUSIONS: The etiology of spinal meningeal cysts remains unclear. Spinal meningeal cysts consisting of dura mater (spinal dural cysts) are extremely rare. Treatment with only decompression with laminectomy causes enlargement of the dural cyst later. Cyst fenestration and placement of a cyst-subarachnoid shunt for the spinal dural cyst resulted in the resolution of myelopathy and cyst shrinkage.

Evaluation of Metallic Artifacts Caused by Nonpenetrating Titanium Clips in Postoperative Neuroimaging.

BACKGROUND: Nonpenetrating titanium clips create no suture holes and thereby reduce cerebrospinal fluid leakage after dural closure. However, no data exist regarding metallic artifacts caused by these clips during postoperative neuroimaging. We aimed to evaluate clip-related artifacts on postoperative magnetic resonance (MR) images of 17 patients who underwent spinal surgery. METHODS: A phantom study evaluated the size of metallic artifacts, and a clinical study evaluated the quality of postoperative spinal MR images. Both 1.5-T studies used T1-weighted and T2-weighted fast spin echo sequences. The phantom study compared clip and artifact size for 10 clips. Artifacts were defined as signal voids surrounded by high signal amplitude that followed the clip shape. In the clinical study, 2 neurosurgeons assessed 22 images from 17 patients of the spinal cord, cauda equina, and paravertebral muscles adjacent to the nonpenetrating titanium clips, using 5-point scales. RESULTS: Mean metallic artifact sizes were 4.82 ± 0.16 mm (T1) and 4.66 ± 0.25 mm (T2; P < 0.001 vs. control). The former and latter were respectively 207% and 200% larger than the clip size. Both readers graded spinal cord and paravertebral muscles images as 3 or 4, indicating very good image quality regardless of clip-related artifacts, with excellent interobserver agreement (κ = 0.99 and 0.98, respectively). CONCLUSIONS: Metallic artifacts caused by nonpenetrating titanium clips were 200% larger than the actual clip but did not affect spinal cord and extradural tissue visualization. The use of these clips for closing the spinal dura mater does not alter postoperative radiologic evaluation quality.

Usefulness of needle holder with a function of fine forceps for bypass surgery in both hands.

BACKGROUND: In bypass surgery, a single-handed needle holder is usually used with other handed fine forceps. Recently, a needle holder with the function of fine forceps has been developed. METHODS: In this technical note, usefulness of newly developed needle holders in both hands is presented in bypass surgery. RESULTS: With this method, surgeons can make stitches and ties by both hands without exchanging instruments. CONCLUSIONS: This method is effective and may result in faster anastomotic procedure comparing with the traditional one.

Early changes in tissue perfusion after tissue plasminogen activator administration in hyperacute ischemic stroke: initial experiences with arterial spin labeling perfusion magnetic resonance imaging.

Cerebral perfusion monitoring is an important component of hyperacute stroke treatment. Arterial spin labeling (ASL) perfusion magnetic resonance (MR) imaging provides a noninvasive method of cerebral perfusion observation. Rapid changes in cerebral perfusion were demonstrated in two patients admitted one hour after onset of hyperacute stroke who underwent recombinant tissue plasminogen activator (rt-PA) treatment. Serial MR images and ASL images were taken on admission and after rt-PA administration. Cerebral blood flow (CBF) values were obtained using the CBF workstation and analysis software. Interpretable ASL images were taken in both patients. Perfusion deficits were consistent with symptoms and/or MR angiography imaging abnormalities. Delayed arterial transit effect was present in one patient; serial imaging showed improvement of CBF after rt-PA treatment in both patients. ASL perfusion MR imaging can provide rapid noninvasive multislice imaging in hyperacute ischemic stroke, and can depict early perfusion deficit and quantify regional CBF concomitantly.

Clip blade scissoring with titanium bayonet clip in aneurysm surgery. Two case reports.

Scissoring of the cerebral aneurysm clip blades is a rare but potentially devastating complication of clipping surgery and results in aneurysm neck injury inducing rupture and/or cerebral infarction. Scissoring has been reported using titanium straight clips. Here we present two unusual cases of crossing of the blades of titanium bayonet clips by a scissors-like mechanism during surgery. The present cases suggest the following points. Bayonet clips in addition to straight clips may display the scissoring phenomenon during clipping surgery. The slipped clip should be removed immediately because the scissor-like deformed aneurysm clip may slip further and result in parent artery stenosis. Scissoring tends to happen in the presence of partial arteriosclerosis of the aneurysm neck. Before a titanium clip is used to treat an aneurysm with partially arteriosclerotic neck, reducing the amount of aneurysm filling by temporary clipping of the main vessel is useful to avoid slippage phenomena.

Overdrainage of cerebrospinal fluid caused by detachment of the pressure control cam in a programmable valve after 3-tesla magnetic resonance imaging.

The authors report a rare case of overdrainage of the CSF caused by the malfunction of a Codman-Hakim programmable valve (CHPV) following a 3-T MR imaging procedure. Nine years ago this 72-year-old woman underwent ventriculoperitoneal shunt placement with a CHPV system for hydrocephalus due to subarachnoid hemorrhage. The postoperative course was uneventful and the system functioned well. A radiograph obtained immediately after 3-T MR imaging revealed that the pressure control cam in the valve system was detached from the base plate. Intracranial hypotension syndrome occurred several hours after the MR imaging study, and a CT scan revealed a decrease in ventricle size. A revision of the system promptly resolved the symptoms, and a postoperative CT scan revealed that the ventricle size was restored to normal. Examination of the extracted valve showed a Y-shaped crack in the plastic housing as well as detachment of the white marker and cam from the base plate. A reduction in the power of the flat spring to press the valve ball led to CSF overdrainage because of a loss of support by the cam. Because the patient had incurred no head injury during the day and radiographic studies of the system 5 years previously had shown detachment of the white marker, damage to the system might have been caused by a past impact. These facts may indicate that the antimagnetic performance of the system could have decreased due to a previous impact and that the strong magnetic force in a 3-T MR imaging environment might have caused detachment of the cam.

Cerebral aneurysm clips in the 3-tesla magnetic field. Laboratory investigation.

OBJECT: The aim of this study was to evaluate cerebral aneurysm clips, and to know in more detail the characteristics of currently available clips in the 3-T magnetic field. METHODS: According to the protocol recommended by the American Society for Testing and Materials (ASTM), the authors conducted quantitative evaluation for displacement force and qualitative evaluation for torque in 52 aneurysm clips and 48 samples of raw materials in the 3-T environment. RESULTS: The largest displacement force occurred near the bore opening, and the force was directed to the isocenter. Deflection angles of all objects in this study were within 45°. The translational force in the peripheral position in the bore was larger than that in the center, and the translational force in the magnetic field was proportional to the weight of the objects. The proportion coefficients varied depending on the metallic materials. In the titanium alloy, the deflection angle was also detected to be approximately 2°, although no response was observed in titanium in a previous report. This behavior was similar to that of the Elgiloy and Phynox materials in the 1.5-T environment. No difference was observed among the groups of shapes (straight, bent, and fenestrated). The amount of torque that occurred was dependent on the clip's or material's loop and bent shape. The torque on the titanium was perpendicular to the torque on the other materials (which was perpendicular to the magnetic field). CONCLUSIONS: Care must be taken with patients near the bore opening while moving them to the center of the magnet's bore on the MR imaging table. Although all the clips examined in this study met the ASTM requirements, the titanium alloy clips are preferable in the 3-T environment for safety's sake. Suitably sized clips should be selected for the aneurysm size, because the translational force increases proportionally to the object's weight.

Investigation of radiofrequency-induced temperature elevation of aneurysm clips in a 3.0-tesla magnetic resonance environment.

OBJECTIVE: Burn injuries associated with excessive heating of medical metallic devices have been reported, but a definite mechanism for magnetic resonance imaging-induced heating remains unresolved. The aim of this study is to evaluate temperature elevation of metallic wires, aneurysm clips, and clips attached to metallic wires under 3.0-T magnetic resonance imaging. METHODS: The temperature of the metallic wires, the aneurysm clips, and the clips attached to the metallic wires was measured with a fiber optic thermometer sensor system. RESULTS: Although the specific absorption rate was less than that observed during standard use, the temperature rapidly increased in the metallic wire. Furthermore, temperature elevation was observed when the clips were attached to metallic wires. On the other hand, not all clips showed obvious temperature elevation when they were placed alone in a 3.0-T magnetic resonance imaging environment. CONCLUSION: Aneurysm clips, when placed alone in a 3.0-T magnetic resonance imaging environment, are confirmed to be safe during temperature elevation.