Transzygomatic Approach with Intraoperative Neuromonitoring for Resection of Middle Cranial Fossa Tumors

The authors reviewed the surgical experience and operative technique in a series of 11 patients with middle fossa tumors who underwent surgery using the transzygomatic approach and intraoperative neuromonitoring (IOM) at a single institution. This approach was applied to trigeminal schwannomas (n = 3), cavernous angiomas (n = 3), sphenoid wing meningiomas (n = 3), a petroclival meningioma (n = 1), and a hemangiopericytoma (n = 1). An osteotomy of the zygoma, a low-positioned frontotemporal craniotomy, removal of the remaining squamous temporal bone, and extradural drilling of the sphenoid wing made a flat trajectory to the skull base. Total resection was achieved in 9 of 11 patients. Significant motor pathway damage can be avoided using a change in motor-evoked potentials as an early warning sign. Four patients experienced cranial nerve palsies postoperatively, even though free-running electromyography of cranial nerves showed normal responses during the surgical procedure. A simple transzygomatic approach provides a wide surgical corridor for accessing the cavernous sinus, petrous apex, and subtemporal regions. Knowledge of the middle fossa structures is essential for anatomic orientation and avoiding injuries to neurovascular structures, although a neuronavigation system and IOM helps orient neurosurgeons.     

海绵窦区神经鞘瘤的诊断及治疗

目的：探索海绵窦区神经鞘瘤的治疗方法。方法：22例MR确诊为海绵窦区神经鞘 瘤的患者经显微外科手术切除肿瘤,其中经颞-颧入路手术者14例,颞-枕经小脑幕入路手术者8例。结果：22例患者中21例（95.5％）肿瘤全切除,1例肿瘤次全切除。切除的肿瘤组织均经病理证实为神经鞘瘤。术后患者的头痛及突眼症状均有不同程度的减轻;外展神经功能障碍的19例中;12例术后3个月外展神经功能有不同程度的恢复;6例动眼神经麻痹患者,4例术后功能恢复;1例肢体活动障碍者恢复良好;并发脑积水者术后积水减少。所有患者术后均获随访,随访时间8-60个月,未见肿瘤复发。肿瘤次全切除的患者,术后3个月行γ-刀治疗,随访2年未见肿瘤复发。结论：经颞-颧或颞-枕经小脑幕入路行显微手术切除海绵窦区神经鞘瘤,可取得较好的疗效。     

岩斜区肿瘤手术入路选择的探讨

目的 探讨岩斜区肿瘤的手术入路选择。对53例岩斜区肿瘤患者的手术治疗进行分析。方法患者采用颞底经天幕入路11例,枕下乙状窦后入路12例;（颧弓或眶颧）翼点入路12例;乙状窦前入路2例;颞底、乙状窦后幕上下联合入路7例;颞下前岩骨硬膜外入路7例;扩大的前颅底硬膜外入路2例。结果32例（61％）患者肿瘤全切除,9例（17％）次全切除,12例（22％）大部切除。术后新发生颅神经功能障碍16例（30％）,死亡2例（4％）。结论枕下乙状窦后入路、颞底经天幕入路等岩斜区手术入路均可以在熟练的显微操作技术及神经导航、神经内镜下进行。主体生长于硬膜外的岩斜肿瘤适合于采用硬膜外入路手术切除。幕上下联合入路对巨大岩斜区肿瘤是理想的手术入路。     

Posterior Fossa Meningioma: Surgical Strategy

Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far.     

Posterior subtemporal transtentorial approach to intraparenchymal lesions of the anteromedial region of the superior cerebellum

OBJECT: To overcome the limitations associated with surgical approaches that have been described for accessing intraparenchymal lesions of the anteromedial region of the superior cerebellum, the authors used a posterior subtemporal transtentorial approach to remove tumors in this region. In this paper they describe the surgical technique that they used as well as the operative findings and clinical outcomes observed in patients who underwent resection of tumors in the anteromedial superior cerebellum. METHODS: The consecutive patients with anteromedial superior cerebellar tumors who underwent resection performed using the posterior subtemporal transtentorial approach at the National Institutes of Health were included in this study. Clinical, neuroimaging, and operative results were analyzed. Three patients (two men and one woman) with anteromedial superior cerebellar tumors (two hemangioblastomas and one pilocytic astrocytoma) underwent resection via this approach. All the tumors were larger than 3 cm in diameter (range 3.1-3.5 cm). This approach provided excellent surgical access and permitted complete tumor resection in each case. The patients remained neurologically unchanged compared with preoperative baseline findings at the last follow-up examination (conducted at 4, 18, and 42 months postoperatively). One patient displayed a mild transient confusion immediately after surgery, but it resolved within 6 days. CONCLUSIONS: The posterior subtemporal transtentorial approach provides excellent access to the anteromedial superior cerebellar region. This approach permits resection of large lesions in this location, while avoiding many of the limitations associated with other approaches to this site.     

显微手术治疗三叉神经鞘瘤

目的 总结各种类型三叉神经鞘瘤手术入路的优缺点。方法 回顾分析１９８０年４月￣１９９７年６月手术治疗的３４例三叉神经鞘瘤的临床效果。结果 肿瘤完全位于中颅窝的３例,均采用颞下入路切除,肿瘤位于后颅窝的１３例,１０例经枕下入路,２例采用颞下经小脑幕入路,１例经乙状窦前入路切除。另１８例哑铃型肿瘤中１４例采用颞下经小脑幕入路,４例采用经颞下－乙状窦前入路切除。结论 颞下入路适用中颅窝型肿瘤切除,枕下入     

Posterior fossa meningioma: surgical strategy

Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far.     

Paramedian hourglass epidermoid cysts extending in the middle and posterior cranial fossa

Four cases of large paramedian hourglass epidermoid tumors extending both in the middle and posterior cranial fossa are reported and other 16 cases from the literature are reviewed. The length of the clinical history and the triviality of neurological symptoms in spite of the size of the tumor are emphasized. CT scanning well documents the extension of these epidermoids and usually consents to differentiate them from the arachnoid cysts. The subtemporal transtentorial approach is more advisable, although a two-stage operation by subtemporal and suboccipital route can be necessary in some cases. Nevertheless the difficulties and the risk of the surgical treatment make very hard the complete removal of the tumor in most cases.     

Surgical management of brainstem cavernomas.

OBJECT: A careful retrospective analysis of 36 cases was performed to evaluate the pre- and postoperative rates of morbidity that occur in patients with brainstem cavernous angiomas. METHODS: The authors evaluated immediate postoperative and follow-up outcomes with regard to clinical findings, the incidence of preoperative hemorrhage(s), location and size of the lesions, and the timing of the surgical procedure after the last hemorrhagic event. Specifically. the following parameters were analyzed: 1) number of hemorrhages; 2) the precise brainstem location (pontomesencephalic, pons, and medulla oblongata); 3) pre- and postoperative cranial nerve status; 4) pre- and postoperative motor and sensory deficits; 5) size (volume) of the lesions; and 6) pre- and postoperative Karnofsky Performance Scale (KPS) scores. Multiple hemorrhages were observed in 16 patients, particularly in those with pontomesencephalic cavernous angiomas (75%). The mean preoperative KPS score was 70.3 +/- 16.3 (+/- standard deviation). Twenty-six patients (72.2%) presented with cranial nerve impairment, 13 (36.1%) with motor deficits, and 17 (47.2%) with sensory disturbance. Volume of the lesions ranged from 0.18 to 18.18 cm3 (mean 4.75 cm3). Postoperative complications included new cranial nerve deficits in 17 patients, motor deficits in three, and new sensory disturbances in 12 patients. In a mean follow-up period of 21.5 months, KPS scores were 80 to 100 in 22 patients. Timing of surgery (posthemorrhage) and multiple hemorrhages did not influence the long-term results. Higher preoperative KPS scores and smaller-volume lesions, however, were factors associated with a better final outcome (p < 0.05). Major morbidity was related mainly to preoperative status and less to surgical treatment. The incidence of new postoperative cranial nerve deficits was clearly lower than that demonstrated preoperatively because of the brainstem hemorrhages. CONCLUSIONS: Based on these findings, resection of brainstem cavernomas is the treatment of choice in the majority of these cases because of the high incidence of morbidity related to one or often several brainstem hemorrhages.     

Paramedian hourglass epidermoid extending above and below the tentorium

The case of a 22-year-old woman with a large hourglass epidermoid tumor extending both below and above the tentorium is presented. The tumor was located in the suprasellar region, left middle cranial fossa, and posterior fossa on the left side. Conventional computerized tomographic (CT) scanning was inconclusive as to the actual extension of the tumor, whereas air encephalography was more helpful. The subtemporal transtentorial approach made it possible to achieve a seemingly radical excision of the tumor. Nevertheless, the CT scan one year later showed the presence of a small tumor mass. The diagnostic and surgical implications are discussed in light of few similar cases reported in the literature.     

Fourth cranial nerve: surgical anatomy in the subtemporal transtentorial approach and in the pretemporal combined inter-intradural approach through the fronto-temporo-orbito-zygomatic craniotomy. A cadaveric study

Despite the recent progress in surgical technology in the last decades, the surgical treatment of skull base lesions still remains a challenge. The purpose of this study was to assess the anatomy of the tentorial and cavernous segment of the fourth cranial nerve as it appears in two different surgical approaches to the skull base: subtemporal transtentorial approach and pretemporal fronto-orbito-zygomatic approach. Four human cadaveric fixed heads were used for the dissection. Using both sides of each cadaveric head, we made 16 dissections: 8 with subtemporal transtentorial technique and 8 with pretemporal fronto-orbito-zygomatic approach. The first segment that extends from the initial point of contact of the fourth cranial nerve with the tentorium (point Q) to its point of entry into its dural channel (point D) presents an average length of 13.5 mm with an extremely wide range and varying between 3.20 and 9.3 mm. The segment 2, which extends from point D to the point of entry into the lateral wall of the cavernous sinus, presents a lesser interindividual variability (mean 10.4 mm, range 15.1–5.9 mm). A precise knowledge of the surgical anatomy of the fourth cranial nerve and its neurovascular relationships is essential to safely approach. The recognition of some anatomical landmarks allows to treat pathologies located in regions of difficult surgical access even when there is an important subversion of the anatomy.     

Microsurgical anatomy of the superior petrosal venous complex: new classifications and implications for subtemporal transtentorial and retrosigmoid suprameatal approaches

OBJECT: The purpose of this study was to define the patterns of drainage of the superior petrosal venous complex (SPVC) along the petrous ridge in relation to the Meckel cave and internal acoustic meatus (IAM) and to delineate its effect on the surgical exposures obtained in subtemporal transtentorial and retrosigmoid suprameatal approaches. METHODS: The patterns of drainage of the SPVC along the petrous ridge were characterized according to their relation to the Meckel cave and the IAM based on an examination of 30 hemispheres. Subtemporal transtentorial and retrosigmoid suprameatal approaches were performed in three additional cadavers to demonstrate the effect of the drainage pattern on the surgical exposures. CONCLUSIONS: The SPVC emptied into the superior petrosal sinus (SPS) within a distance of 1 cm from the midpoint of the Meckel cave. The patterns of drainage of the SPVC were classified into three groups. Type I emptied into the SPS above and lateral to the boundaries of the IAM. The most common type, Type II, emptied between the lateral limit of the trigeminal nerve at the Meckel cave and the medial limit of the facial nerve at the IAM, within an area of approximately 13 mm. Type III emptied into the SPS above or medial to the Meckel cave. The ideal SPVC for a subtemporal transtentorial approach (with or without anterior extradural petrosectomy) seems to be a Type I. In SPVC Type III and those Type II cases in which the SPVC is located near the Meckel cave, the amount of working space is significantly limited in a subtemporal transtentorial approach. In contrast, the ideal type of SPVC for a retrosigmoid suprameatal approach would be a Type III, and the SPVC must be divided in the majority of Type I and II cases for a satisfactory surgical exposure along the Meckel cave and middle fossa dura. The proposed modified classification system and its effect on the surgical exposure may aid in planning the approach directed along the petrous apex and may reduce the probability of venous complications.     

骶骨骨巨细胞瘤的外科治疗

目的 探讨骶骨骨巨细胞瘤外科切除边界与局部复发率及骶神经保留节段与神经功能的关系.方法 对1996年8月至2008年8月行肿瘤切除的48例骶骨骨巨细胞瘤患者进行回顾性分析,男20例,女28例;年龄19～74岁,平均34.7岁.肿瘤累及S1～S5 4例,S1～S4 7例,S1～S3 15例,S1,2 12例,S2～S5 8例,S3～S5 2例.采用单纯后路29例,前后联合入路19例.整块切除2例,边缘切除12例,边缘切除加刮除25例,刮除9例.术后定期随访,观察局部复发情况与骶神经功能.结果 41例随访18～115个月,平均43.5个月.术中出血量550～12000 ml,平均3560 ml.1例发生良性肺转移,2例发生肉瘤变后死亡.15例肿瘤原位复发,其中整块切除复发率0(0/2)、边缘切除18.2%(2/11)、边缘切除加刮除40.9%(9/22)、单纯刮除66.7%(4/6).边缘切除局部复发率低于单纯刮除,差异有统计学意义.保留双侧S3神经根者大小便功能障碍发生率7.4%(2/27),保留单侧S3神经根者33.3%(4/12),差异有统计学意义.结论 外科切除边界与骶骨骨巨细胞瘤局部复发率相关,在注意保留骶神经根的前提下应以边缘切除为目标;保留双侧S3神经根可使绝大部分患者的括约肌功能得以恢复.

Abstract：

Objective To discuss the relations between optimal surgical margin and local recurrence and the impact of preserving segment of sacral nerve root on neural functions based on the clinical and pathological features of giant cell tumor(GCT).Methods From August 1996 to August 2008,48 patients with sacral GCT undergoing tumor resection were respectively analyzed,including 20 males and 28 females with an average of 34.7 years(range,19-74).The tumors were located in S1-S5 in 4 patients,S1-S4 in 7,S1-S3 in 15,S1,2 in 12,S2-S5 in 8,and S3-S5 in 2.Surgical methods included single posterior approach in 29 cases,combined anterior-posterior approach in 19.The surgical margins adopted were en-bloc in 2 patients,marginal in 15,marginal and curettage in 25,and curettage in 9.Results Forty-one of 48 cases were successfully followed up,the average time was 43.5 months(range,18-115).The average blood loss during surgery was 3560 ml(range,550-12 000).Benign lung metastasis occurred in one case 6 years after operation,2 patients died of malignant transformation.Local recurrence occurred in 15 cases.The recurrence rates in patients with en-bloc resection,marginal resection,marginal resection combined with curettage,and curettage were 0,18.2%,40.9%,66.7%,respectively.The recurrence rate of marginal group was significantly lower than that of the curettage group.Of 27 cases with bilateral S3 nerve root preservation,2 sufiered from urine or fetal dysfunction.with an incidence rate of 7.4%.While 4 of 12 patients with unilateral S3 nerve root preservation suffered from sphincter disturbance,with an incidence rate of 33.3%.The significant difference between groups in nerve root preservation was confirmed.Conclusion Optimal surgical margin for sacral GCT is of great importance to local control of tumor recurrence,the surgical procedure of sacral GCT should aim at the marginal resection on the basis of rational sacral nerve roots preservation;preservation of bilateral S3 nerve roots contributes to the recovery of sphincteral function in most patients.     

Side-Cutting Aspiration Device for Endoscopic and Microscopic Tumor Removal

The authors present a unique side-cutting instrument (NICO Myriad, Indianapolis, IN) with variable aspiration designed specifically for tumor resection. The study included retrospective review of data collected from 10/2009 to 01/2011. We detail the use of the Myriad in 31 patients with the following pathologies: meningioma (n=16), chordoma (n = 3), schwannoma (n = 3), pituitary adenoma (n = 2), metastasis (n = 3), hemangioblastoma (n = 1), craniopharyngioma (n = 1), and nasopharyngeal tumors (n = 2). Surgical approaches included expanded endonasal approach (n = 19), endoscopic brain port (n = 3), supraorbital “eyebrow” craniotomy (n = 3), retrosigmoid suboccipital craniotomy (n = 3), pterional craniotomy (n = 1), extreme far lateral (n = 1), and laminectomy (n = 1). Successful tumor resection was achieved in 30 cases. Instrument failure was noted in only one extremely fibrous meningioma. The design of this instrument facilitated maneuvering through narrow corridors while providing direct visualization of the suction aperture during tumor resection. These features allowed for tumor removal without injury to adjacent neurovascular structures. The side-cutting aspiration device allows safe and effective tumor removal. Its low profile, variable aspiration, and lack of thermal heat energy are particularly useful in tumor resection through narrow corridors, such as endonasal, port, and keyhole approaches. The multifunctional nature of the instrument (suction, scissors, and dissectors) minimizes multiple exchanges, facilitating tumor resection through these minimal access corridors.     

Posterior petrous meningiomas: 82 cases

OBJECT: The aim of this study was to discuss posterior petrous meningiomas--their classification, clinical manifestations, surgical treatments, and patient outcomes. METHODS: A retrospective analysis was performed in 82 patients with posterior petrous meningiomas for microsurgery. According to the anatomical relationship with the posterior surface of the petrous bone and with special reference to the internal auditory canal (IAC), posterior petrous meningiomas were classified into three types: Type I, located laterally to the IAC (28 cases); Type II, located medially to the IAC, which might extend to the cavernous sinus and clivus (32 cases); and Type III, extensively attached to the posterior surface of the petrous bone, which might envelop the seventh and eighth cranial nerves (22 cases). Sixty-eight (83%) of 82 cases involved total resection. The rate of anatomical preservation of facial nerve was 97.5%, whereas the functional preservation rate was 81%. The rate of hearing preservation was 67%. All Type I tumors were completely resected, and the rate of anatomical preservation of facial nerve was 100% and functional preservation was 93%. Regarding Type II lesions, 75% of 32 cases involved total resection; the rate of anatomical preservation of facial nerve was 97% and functional preservation was 75%. For Type III lesions, 73% of 22 cases were totally resected. The rate of anatomical preservation of facial nerve in patients with this tumor type was 95%, whereas functional preservation was 73%. CONCLUSIONS: Clinical manifestations and surgical prognoses are different among the various types of posterior petrous meningiomas. It is more difficult for Types II and III tumors to be resected radically than Type I lesions, and postoperative functional outcomes are significantly worse accordingly. The primary principles in dealing with this disease entity include preservation of vital vascular and central nervous system structures and total resection of the tumor as much as possible.     

Foramen magnum meningiomas: experiences in 114 patients at a single institute over 15 years

BackgroundAlthough there has been great development in the anatomical understanding and operative techniques for skull base tumors, controversy still exists regarding the optimal surgical strategies for the FMMs. We report clinical and radiologic features as well as the surgical findings and outcome for patients with FMM treated at our institution over the last 15 years.MethodsWe reviewed 114 consecutive cases of FMM operated between May 1993 and June 2008 in the neurosurgery department at Beijing Tiantan Hospital.ResultsThere were 68 female and 46 male patients (mean age, 52.3 years; range, 28-76 years). Foramen magnum meningiomas were classified as anterior (80 cases), anterolateral (24 cases), and posterolateral (10 cases). Mean duration of symptoms was 11.7 months (ranging from 1.5 to 240 months). Cervico-occipital pain (80.7%) and headache and dizziness (42.1%) were the most common presenting symptoms. The preoperative KPS was 72.5 ± 8.3. Mean maximum diameter of the tumors on MRI was 3.35 cm (range, 1.5-4.7 cm). Posterior midline approach was performed in 10 cases, far-lateral retrocondylar approach in 97 cases, and extended far-lateral approach in 7 cases. Gross total resection was achieved in 86.0% of patients and subtotal resection in 14.0%. Surgical mortality was 1.8%. Follow-up data were available for 93 patients, with a mean follow-up of 90.3 months (range, 1-180 months), of which 59 (63.4%) lived a normal life (KPS, 80-100).ConclusionOur experience suggests that most anterior and anterolateral FMMs can be completely resected by a far-lateral retrocondylar approach without resection of the occipital condyle. Complete resection of the tumor should be attempted at the first operation. Postoperative management of FMM is important for the prognosis.     

98例成人原发性腹膜后恶性肿瘤的诊治分析

目的探讨成人原发性腹膜后恶性肿瘤（APRMT）的诊断方法和手术经验。方法对1990年1月至2003年4月经手术治疗的98例APRMT患者的临床资料进行分析。结果98例成人原发性腹膜后恶性肿瘤中,肿瘤完全切除79例（80．6％）,姑息性切除16例（16．3％）,肿瘤探查和单纯活检3例（3．1％）,合并脏器切除25例（25．5％）;复发再次手术者28例（28．6％）。肿瘤完全切除的79例患者的1、3、5年生存率分别为93．7％、73．4％和34．2％,姑息性切除的1、3、5年生存率分别为75．O％、6．3％和6．3％。结论联合应用合理的影像学检查对判断APRMT肿瘤周围器官是否受累和切除范围有重要意义,充分的术前准备和受累器官的联合切除可以提高APRMT切除率和预后,对于复发病例,应争取尽早再次手术治疗。     

Association of Morbidity with Extent of Resection and Cavernous Sinus Invasion in Sphenoid Wing Meningiomas

Sphenoid wing meningiomas (SWMs) typically are histologically benign, insidious lesions, but the propensity of these tumors for local invasion makes disease control very challenging. In this review, we assess whether the degree of resection and extent of cavernous sinus invasion affects morbidity, mortality, and recurrence in patients with SWM. A comprehensive search of the English-language literature was performed. Patients were stratified according to extent of resection and extent of cavernous sinus invasion, and tumor recurrence rate, morbidity, and mortality were analyzed. A total of 23 studies and 131 patients were included. Overall recurrence and surgical mortality rate were 11% and 2%, respectively (average follow-up = 65 months). Cranial nerve III palsy was significantly associated with incompletely versus completely resected SWMs (7 to 0%) as well as meningiomas with cavernous sinus invasion versus no sinus invasion (14 vs. 0%). No significant difference in tumor recurrence rate was noted between these groups. In conclusion, complete excision of SWMs is always recommended whenever possible, but surgeons should acknowledge that there is nonetheless a chance of recurrence and should weigh this against the risk of causing cranial nerve injuries.     

Microsurgical management of spinal schwannomas: evaluation of 128 cases

OBJECT: The authors conducted a study to evaluate the clinical characteristics and surgical outcomes in patients with spinal schwannomas and without neurofibromatosis (NF). METHODS: The data obtained in 128 patients who underwent resection of spinal schwannomas were analyzed. All cases with neurofibromas and those with a known diagnosis of NF Type 1 or 2 were excluded. Karnofsky Performance Scale (KPS) scores were used to compare patient outcomes when examining the anatomical location and spinal level of the tumor. The neurological outcome was further assessed using the Medical Research Council (MRC) muscle testing scale. RESULTS: Altogether, 131 schwannomas were treated in 128 patients (76 males and 52 females; mean age 47.7 years). The peak prevalence is seen between the 3rd and 6th decades. Pain was the most common presenting symptom. Gross-total resection was achieved in 127 (97.0%) of the 131 lesions. The nerve root had to be sacrificed in 34 cases and resulted in minor sensory deficits in 16 patients (12.5%) and slight motor weakness (MRC Grade 3/5) in 3 (2.3%). The KPS scores and MRC grades were significantly higher at the time of last follow-up in all patient groups (p = 0.001 and p = 0.005, respectively). CONCLUSIONS: Spinal schwannomas may occur at any level of the spinal axis and are most commonly intradural. The most frequent clinical presentation is pain. Most spinal schwannomas in non-NF cases can be resected totally without or with minor postoperative deficits. Preoperative autonomic dysfunction does not improve significantly after surgical management.     

Surgical management of brainstem cavernomas: selection of approaches and microsurgical techniques

This study reviewed surgical experience with brainstem cavernomas in an attempt to define optimal surgical approaches and risks associated with surgical management. Clinical courses were retrospectively reviewed for 36 consecutive patients (12 men, 24 women; mean age, 42 years) who underwent microsurgical resection of brainstem cavernomas between 1996 and 2006. Medical records, surgical records, and neuroimaging examinations were evaluated. All 36 patients presented with ≥1 hemorrhage from the cavernomas and preoperatively displayed some neurological symptoms. Surgical approach was midline suboccipital for 16 pontine and/or medullary cavernomas under the floor of the fourth ventricle, retrosigmoid for 10 lateral mesencephalic, pontine, and/or medullary cavernomas, occipital transtentorial for 2 thalamomesencephalic and 3 mesencephalic cavernomas, combined petrosal for 2 pontine cavernomas, and other for 3 cavernomas. Complete resection according to postoperative magnetic resonance imaging was achieved in 33 of 36 patients. No mortality was encountered in this study. New neurological deficit occurred in the early postoperative period for 18 patients, but was transient in 15 of these. Neurological state as of final follow-up was improved in 16 patients (44%), unchanged in 17 (47%), and worsened in 3 (8%) compared with preoperatively. In conclusion, symptomatic brainstem cavernomas should be considered for surgical treatment. Careful selection of the optimal operative approach and a meticulous microsurgical technique are mandatory.