Biographies of international women leaders in neurosurgery.

We received so many biographies of women neurosurgery leaders for this issue that only a selection could be condensed here. In all of them, the essence of a leader shines through. Many are included as "first" of their country or color or other achievement. All of them are included as outstanding-in clinical, academic, and organized neurosurgery. Two defining features are tenacity and service. When faced with shocking discrimination, or numbing indifference, they ignored it or fought valiantly. When choosing their life's work, they chose service, often of the most neglected-those with pain, trauma, and disability. These women inspire and point the way to a time when the term "women leaders" as an exception is unnecessary.-Katharine J. Drummond, MD, on behalf of this month's topic editors.

Non-operative meningiomas: long-term follow-up of 136 patients.

BACKGROUND: Improving access to neuroradiology investigations has led to an increased rate of diagnosis of incidental meningiomas. METHOD: A cohort of 136 incidental meningioma patients collected by a single neurosurgeon in a single neurosurgical centre is retrospectively analysed between 2002 and 2016. Demographic data, imaging and clinical features are presented. The radiological factors associated with meningiomas progression are also presented. RESULTS: The mean age at diagnosis was 65 (range, 33-94) years. Univariate analysis showed oedema was most strongly correlated with progression (p = 0.010) followed by hyperintensity in T2-weighted (T2W) MRI (p = 0.029) and in Flair-T2W MRI (p = 0.017). Isointensity in Flair-T2W MRI (0.004) was most strongly correlated with non-progression of the meningioma followed by calcification (p = 0.007), older age (p = 0.087), hypointensity in Flair-T2W MRI (p = 0.014) sequences and in T2W MRI (p = 0.096). In multivariate analysis, the strongest radiological factor predictive of progression was peritumoural oedema (p = 0.016) and that of non-progression was calcification (p = 0.002). At the end of the median follow-up (FU) of 43 (range, 4-150) months, 109 (80%) patients remained clinically stable, 13 (10%) became symptomatic and 14 (10%) showed clinical and radiological progression. CONCLUSIONS: One hundred and nine (80%) patients remained stable at the end of FU. Peritumoural oedema was predictive of meningiomas progression. Further prospective study is needed to identify the combination of factors which can predict the meningioma progression for an early surgery or early discharge.

Diffusion tensor magnetic resonance imaging for predicting the consistency of intracranial meningiomas.

BACKGROUND: The ability of preoperative MRI-sequences to predict the consistency of intracranial meningiomas has not yet been clearly defined. We aim to demonstrate that diffusion tensor imaging (DTI) improves the prediction of intracranial meningiomas consistency. METHODS: We prospectively studied 110 meningioma patients operated on in a single center from March 1st to the 25th of May 2012. Demographic data, location and size of the tumor, peritumoral edema, T1WI, T2WI, proton density weighted (PDWI), fluid-attenuated inversion recover (FLAIR) sequences, and arterial spin labeling (ASL) perfusion were studied and compared with the gray matter signal to predict meningioma consistency. Diffusion tensor imaging (DTI) with fractional anisotropy (FA) and mean diffusivity (MD) maps were included in the preoperative MRI. Meningioma consistency was evaluated by the operating surgeon who was unaware of the neuroradiological findings. RESULTS: In univariate analysis, meningioma size (diameter > 2 cm) and supratentorial or sphenoidal wing location were more frequently associated with hard-consistency meningiomas (p < 0.05). In addition, isointense signal on MD maps (p = 0.009), hyperintense signal on FA maps, and FA value > 0.3 (p = 0.00001) were associated with hard-consistency tumors. Age and sex, T1WI, T2WI, PDWI, FLAIR, or ASL perfusion sequences and peritumoral edema were not significantly associated with meningioma consistency. In logistic regression analysis, the most accurate model (AUC: 0.9459) for predicting a hard-consistency meningioma shows that an isointense signal in MD-maps, a hyperintense signal in FA-maps, and an FA value of more than 0.3 have a significant predictive value. CONCLUSIONS: FA value and MD and FA maps are useful for prediction of meningioma consistency and, therefore, may be considered in the preoperative routine MRI examination of all patients with intracranial meningiomas.

The Use of the Suboccipital Transtentorial Approach to the Posterior Inferior Incisural Space.

Objective To describe our experience with the microsurgical technique of the suboccipital transtentorial (SOTT) approach in the removal of posterior fossa lesions located in the posterior incisural space. Method Between 2002 and 2020 we reviewed all patients who underwent microsurgical resection of lesions of the posterior incisural space at the Department of Neurosurgery, Essex Neuroscience Centre, London, England (eight patients, male to female 3:5, mean age: 51, range 35-69). We describe the preoperative symptoms, radiological findings, surgical techniques, histology and postoperative outcomes in this cohort of patients. Results Eight patients with tumours located in the posterior incisural space underwent surgery during the study period including four meningiomas (50%), two haemangioblastomas (25%), one metastasis (13%) and one giant prolactinoma (13%). Gross or near total resection was achieved in six patients (75%): the giant prolactinoma could not be radically removed and one of the meningiomas required a small fragment to be left in place to protect the Vein of Galen. No patient developed a visual field deficit due to occipital lobe retraction. One patient developed a temporary trochlear nerve palsy (13%). Five patients had mild disability (Glasgow Outcome Scale (GOS) = 5), and four had moderate disability (GOS = 4). Conclusion In our series, the SOTT approach provided excellent access for all cases of tumours in the posterior incisural space. The tumour's size and relationship to the deep venous system contributed to the choice of approach and in one patient who had previously undergone surgery via the supracerebellar route, the SOTT approach enabled the avoidance of gliotic scar tissue. Success is dependent on careful case selection, though from our series of 8 patients, we conclude that this approach allows safe access to the posterior incisural space, with acceptable outcomes with regard to postoperative disability and cranial nerve palsy. As such, the approach should be in the armamentarium of any neurosurgeon who regularly deals with posterior fossa pathology.

Thromboelastometry during intraoperative transfusion of fresh frozen plasma in pediatric neurosurgery.

Normal blood coagulation is essential in pediatric neurosurgery because of the risk of abundant bleeding, and therefore it is important to avoid transfusion of fluids that might interfere negatively with the coagulation process. There is a lack of transfusion guidelines in massive bleeding with pediatric neurosurgical patients, and early use of blood compounds is partly controversial. We describe two pediatric patients for whom fresh frozen plasma (FFP) infusion was started at the early phase of brain tumor surgery to prevent intraoperative coagulopathy and hypovolemia. In addition to the traditional laboratory testing, modified thromboelastometry analyses were used to detect possible disturbances in coagulation. Early transfusion of FFP and red blood cells preserved the whole blood coagulation capacity. Even with continuous FFP infusion, fibrin clot firmness was near to critical value at the end of surgery despite increased preoperative values. By using FFP instead of large amounts of crystalloids and colloids when major blood loss is expected, blood coagulation is probably less likely to be impaired. Our results indicate, however, that the capacity of FFP to correct fibrinogen deficit is limited.

Women in neurosurgery in the United Kingdom: past, present and future.

Whilst a growing number of women in the United Kingdom (UK) are making a success of a career in medicine as a whole, a considerable gender imbalance persists in neurosurgery. The extent of this disparity and the factors that perpetuate it are difficult to assess. Furthermore, over the 70 years since the first female neurosurgeon in the UK commenced her postgraduate training, it is difficult to gauge the progress that has been made. In this article we present a snapshot of women who have played, and who are playing, a key role in UK neurosurgery, highlighting their diverse career paths. We also present the current training distribution and subspecialties of women in UK neurosurgery. We use these data to reflect upon the possible barriers to completion of neurosurgical training, obtaining a substantive consultant position, and reaching positions of academic and clinical leadership. We discuss potential interventions that may overcome these. Highlighting the role women play in UK neurosurgery's past, present and future should inspire more female neurosurgeons to become leaders in the coming years.

Down-regulation of miR-7-5p and miR-548ar-5p predicts malignancy in indeterminate thyroid nodules negative for BRAF and RAS mutations.

PURPOSE: The value of molecular markers in refining preoperative risk assessment of indeterminate thyroid nodules is being widely investigated. MicroRNAs (miRNA) are emerging as promising biomarkers for diagnostic and prognostic purposes. The aim of this study is to identify miRNAs specifically deregulated in mutation-negative indeterminate thyroid nodules. METHODS: Ninety-eight nodules preoperatively diagnosed as TIR 3A or TIR 3B with available histological diagnosis of follicular adenoma (FA), noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP), and follicular variant papillary thyroid carcinoma (FV-PTC) have been retrospectively selected. Mutations in BRAF and RAS genes have been tested in all samples by real-time PCR; miRNAs were purified from cytology slides of 60 samples; expression analysis of 798 miRNAs was measured by the nCounter system. RESULTS: Point mutations in BRAF and RAS genes were detected in 32 out of 98 nodules (32.7%), the majority of which in FV-PTCs. Differential expression of miRNA in wild-type nodules highlighted that two miRNAs, namely miR-7-5p and miR-548ar-5p, were downregulated in FV-PTCs compared to FAs. The combined expression of these miRNAs, tested by ROC analysis, showed an area under the curve of 0.79. Sensitivity and negative predictive value were high both in wild-type (93% and 92%, respectively) and in mutated nodules (94% and 85%, respectively). CONCLUSION: The analysis of miR-7-5p and miR-548ar-5p expression in indeterminate thyroid nodules demonstrated a promising value in ruling out malignancy.

The Italian Consensus for the Classification and Reporting of Thyroid Cytology: Cytohistologic and molecular correlations on 37,371 nodules from a single institution.

BACKGROUND: The Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC) includes six diagnostic categories (TIR 1/1C, TIR 2, TIR 3A, TIR 3B, TIR 4, and TIR 5), each indicating a different risk of malignancy. The objective of this monocentric retrospective study was to evaluate the distribution of the ICCRTC classes at the authors' institution and assess their cytohistologic correlations. METHODS: The authors retrospectively collected 37,371 consecutive cytologic reports of thyroid nodules and described the clinical-pathologic features of the different cytologic categories. The cytologic diagnoses also were compared with histologic outcomes in a subset of patients. RESULTS: The cytologic classes were distributed as follows: nondiagnostic, 15.6%; benign, 66.5%; low-risk indeterminate, 10% (TIR 3A); high-risk indeterminate, 3.5% (TIR 3B); suspicious, 1.7%; and malignant, 2.6%. According to histology, the risk of malignancy was very high in the nondiagnostic category (29.8%), with young male patients more exposed to malignancy, and it was relatively high among benign (7.8%) and indeterminate nodules (32.5% in TIR 3A; 52.1% in TIR 3B), mainly because of the high prevalence of follicular architecture in malignant tumors. On histology, the malignancy rates were 92.4% and 99.3% for the suspicious and malignant categories, respectively; aggressive variants of papillary thyroid carcinoma were mostly diagnosed in these categories. CONCLUSIONS: In this series, nondiagnostic nodules showed high prevalence and, surprisingly, high malignancy rates. Malignant tumors with follicular architecture represented a diagnostic pitfall in benign and indeterminate nodules. The suspicious and malignant categories had high specificity for malignancy. Importantly, the ICCRTC had high reliability for identifying preoperatively aggressive histotypes of thyroid carcinoma.

Present state of microneurosurgery of cerebral arteriovenous malformations.

Microneurosurgical excision is known to be the definitive treatment for brain arteriovenous malformation (AVMs). The most important factors governing the operability of an AVM are location, size, age of the patient, and the neurosurgeon's and team's experience. We present in this review the surgical experience of the senior author (JH) in microneurosurgical treatment of brain AVMs. This consists of the following steps: (1) accurate preoperative embolization; (2) optimal selection of the surgical approach; (3) accurate definition and preservation of the normal arterial vessels of passage; (4) temporary clipping of the feeding arteries; (5) a special method of coagulation called "dirty coagulation" of the deep small difficult vessels inside apparently normal brain around the AVM; (6) removal of all AVM; (7) meticulous hemostasis; (8) intra- and postoperative digital subtraction angiography (DSA); (9) clinical and radiological follow-up. These steps are not possible in AVMs lying entirely within central eloquent areas. Nine out of ten small- and medium-sized arteriovenous malformations (AVMs) are suitable for direct surgery, but surgical complications increase drastically with the size of the AVM. Nevertheless, the actual results of combined treatment with preoperative Onyx embolization followed by microsurgery have decreased these risks.

Application of microscope integrated indocyanine green video-angiography during microneurosurgical treatment of intracranial aneurysms: a review.

Indocyanine Green Video Angiography (ICG-VA) is recently introduced to the practice of cerebrovascular neurosurgery. This technique is safe and noninvasive and provides reliable real-time information on the patency of blood vessels of any size, as well as residual filling of aneurysms. In this article, a review of the literature and our experience with ICG-VA during microneurosurgery of intracranial aneurysms is presented.

Microsurgical principles for anterior circulation aneurysms.

Microneurosurgical techniques introduced by Prof. Yasargil have been modified by the senior author (JH) when treating more than 4,000 patients with aneurysms at two of the Departments of Neurosurgery in Finland, Kuopio and Helsinki, with a total catchment area of close to three million people. This experience is reviewed, and the treatment of anterior circulation aneurysms by simple, fast, normal anatomy preserving strategy is presented.Most of the aneurysms of the anterior circulation are treated by using the lateral supraorbital approach, a less invasive, more frontally located modification of the pterional approach. To avoid extensive skull base surgery, a slack brain is needed and achieved by experienced neuroanesthesia and by surgical tricks for removal of CSF.Diagnosis of cerebral aneurysm before rupture improves treatment results more than any technical advances. Until this is realized, we continue to treat cerebral aneurysms by simple, fast, preserving normal anatomy-strategy, which has served our patients well.Patients with cerebral aneurysms should be treated at specialized neurovascular centers.

Ectopic recurrence of craniopharyngioma along the surgical route: case report and literature review.

We present a 22-year-old woman with an ectopic recurrence of a craniopharyngioma. The patient presented first with a visual field deficit, and a craniopharyngioma was removed via an interhemispheric transcallosal approach. Magnetic resonance imaging (MRI) performed at 1 month, and then at 1 year after surgery showed complete removal of the lesion. However, at 4 years, MRI showed the presence of a small tumor in the right medial frontal lobe attached to the falx and along the previous surgical route. We present possible explanations for the ectopic recurrence and literature review.

Digital Gene Expression Analysis on Cytology Smears Can Rule Out Malignancy in Follicular-Patterned Thyroid Tumors.

Patients with indeterminate thyroid nodules (Bethesda III and IV) are often treated with diagnostic lobectomy, which in most cases represents an overtreatment. A reliable rule-out molecular test could spare patients unnecessary surgery. Stained smears of 88 indeterminate thyroid nodules with histologic diagnosis of follicular-patterned tumors were selected: 34 follicular adenomas (FAs), 34 follicular variant papillary thyroid carcinomas (FVPTCs), and 20 noninvasive follicular neoplasms with papillary-like nuclear features (NIFTPs). The expression level of 126 genes was measured by digital counting. Mutation testing was performed for the main gene mutations and fusions. Performance of gene expression and mutation tests was calculated by receiver operating characteristic analysis. The gene expression model showed an area under the curve (AUC) of 88%, with 91% negative predictive value in FAs and FVPTCs only. Part of NIFTPs was labeled as benign, and part was labeled as malignant; thus, the classifier performance worsened. Two FAs (5.9%), eight NIFTPs (40%), and 22 FVPTCs (64.7%) were mutation positive. Mutation testing AUC was 79% in FAs and FVPTCs, and decreased by including NIFTPs. This gene expression-based test was feasible in thyroid-stained smears, showed higher AUC than mutation test, and had a high negative predictive value-making it a good candidate as a rule-out test for indeterminate thyroid cytology. NIFTPs have a heterogeneous phenotype, and their preoperative diagnosis requires further investigation.

Lower trunk of brachial plexus injury in the neonate rat: effects of timing repair.

OBJECTIVE: After lesion of a peripheral nerve in neonatal mammals, motoneurons undergo a cell death. We wanted to ascertain if early surgery could influence such post-axotomy motoneuronal death and improve the functional outcome. In this study, we investigated the functional and anatomical results after immediate and delayed repair of the lower trunk of brachial plexus (BP) sectioned at birth in rats. METHODS: In neonate rats, the lower trunk of the left BP was cut. This nerve trunk was repaired either immediately [immediately-reconstructed group of rats (IR), or 30 days after, tardy reconstructed group of rats (TR)]; in the third group of animals, the nerve was not repaired (noreconstructed group of rats, NoR). In each group of animals, functional studies were performed at 90 days of age using the grooming test and the walking tracks analysis. Histologic studies of the C7-T1 spinal cord and lower trunk of BP were performed at 30 and 90 days of age; the numbers of motoneuron and axon were counted. RESULTS: Functional recovery was related to the difference in motoneuron number between the injured and the uninjured sides of the spinal cord of the operated animals. On the one side, only in the rats in which the inferior trunk was immediately repaired, the difference in motoneuron number between the two sides of the spinal cord was not statistically significant; these animals showed a good axonal regeneration and function recovery. On the other side, in the rats in which the inferior trunk was left unrepaired or tardy repaired, the decrease in motoneuron number in the injured side compared with the uninjured side of the spinal cord was statistically significant; these animals showed no axonal regeneration and no function recovery. DISCUSSION: The results cited above suggest that an important role in restoration of good neurological function after section of the lower trunk of BP in neonate rats is played by early nerve repair. Good neurological function was related more to a quite numerical balance of motoneurons between the two anterior gray horns of spinal cord than to the absolute number of rescued motoneurons.

Microneurosurgical management of internal carotid artery bifurcation aneurysms.

BACKGROUND: Internal carotid artery bifurcation aneurysms form 2% to 9% of all IAs. They are more frequent in younger patients than other IAs. In this article, we review the practical microsurgical anatomy, the preoperative imaging, surgical planning, and the microneurosurgical steps in the dissection and the clipping of ICAbifAs. METHODS: This review and the whole series on IAs are mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve, without patient selection, the catchment area in Southern and Eastern Finland. RESULTS: These 2 centers have treated more than 11 000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 IAs, 831 (28%) patients had altogether 980 ICA aneurysms, of whom 137 patients had 149 (4%) ICAbifAs. Ruptured ICAbifAs, found in 78 (52%) patients, with median size of 8 mm (range, 2-60 mm), were associated with ICH in 15 (19%) patients. Ten (7%) ICAbifAs were giant (> or = 25 mm). Multiple aneurysms were seen in 59 (43%) patients. The ICAbifAs represented 18% of all IAs ruptured before the age of 30 years. CONCLUSIONS: The main difficulty in microneurosurgical management of ICAbifAs is to preserve flow in all the perforators surrounding or adherent to the aneurysm dome. This necessitates perfect surgical strategy based on preoperative knowledge of 3D angioarchitecture and proper orientation during the microsurgical dissection.

Microsurgical treatment of third ventricular colloid cysts by interhemispheric far lateral transcallosal approach--experience of 134 patients.

BACKGROUND: Colloid cysts are rare tumors (incidence 3.2/1000000 pear year) located in the anterosuperior part of the third ventricle. In this article, we present our microneurosurgical experience on 134 patients focusing on the nuances of ITA with demonstrative videoclips. METHODS: This surgical series is based on the microsurgical experience of the senior author (JH) at 2 Finnish neurosurgical centers (Helsinki and Kuopio, 1980-2007). Surgical anatomy is demonstrated, and the pitfalls of the different surgical steps are analyzed to avoid complications. The series reflects the whole patient profile of Southern and Eastern Finland, without any selection bias. RESULTS: There was no surgical mortality, and morbidity remained mainly transitory among 134 patients treated by ITA. CONCLUSIONS: Favorable overall outcome of this series demonstrates that removal of third ventricular colloid cyst via transcallosal approach is a direct and safe way to treat these lesions.

Microsurgical management of pineal region lesions: personal experience with 119 patients.

BACKGROUND: Lesions of the pineal region are histopathologically heterogeneous but often accompanied with severe progression of clinical signs. Surgical treatment remains challenging because of the close vicinity of the deep venous system and the mesencephalo-diencephalic structures in this region. We present the surgical approaches and techniques in a consecutive series of 119 patients treated by the senior author (J.H.) between 1980 and 2007 at 2 different neurosurgical university centers in Kuopio and Helsinki, Finland. METHODS: Of the included patients, 107 (90%) presented with pineal region tumors and 12 (10%) with vascular malformations. The ITSC route was used for removal of the lesion in 111 (93%) patients and the OIH approach in 8 (7%) patients. All except one patient were operated on in a sitting position. RESULTS: We reviewed all clinical data and radiographic images and analyzed all surgical videos. The pineal lesions were removed completely in most cases (88%). There was no surgical mortality. Twenty-two (18%) of the patients had complications in the postoperative period; these included 1 epidural hematoma, 9 transient Parinaud syndrome, 2 meningitis, 3 wound infections, 2 transient memory disturbances, 2 mild hemiparesis, 1 CSF fistula, and 2 cranial nerves palsies (IV and VI). During a 3.5-year follow-up, 12 patients with malignant lesions died; all patients with benign tumors survived. CONCLUSIONS: The ITSC route is a safe and effective surgical approach, associated with low morbidity, complete lesion removal, and definitive histopathologic diagnosis. Considering risk vs benefit, we therefore believe that the surgical treatment can be offered in most cases as the first treatment option for pineal tumors.

Patients with Indeterminate Thyroid Nodules at Cytology and Cancer at Histology Have a More Favorable Outcome Compared with Patients with Suspicious or Malignant Cytology.

BACKGROUND: The outcomes of patients with thyroid cancer proven by histology in patients in whom cytology was Thy 3 (indeterminate; Thy 3 patients in this study) based on the Italian consensus classification compared with those in whom cytology was Thy 4 (suspicious for malignancy) or Thy 5 (indicative for malignancy) (Thy 4-5 patients here) remains unclear. OBJECTIVE: To analyze the outcome of 371 Thy 3 patients versus 269 Thy 4-5 patients homogeneously treated with total thyroidectomy and 131I activity. RESULTS: T1 stage was observed in 46.0% of Thy 3 and in 38.8% of Thy 4-5 patients (p = 0.02), N0 in 95.9% of Thy 3 and in 75.5% of Thy 4-5 patients (p < 0.0001). 35/261 (9.6%) Thy 3 and 85/269 (31.5%) Thy 4-5 patients required >30 mCi of 131I (p < 0.0001). 359/371 (96.8%) Thy 3 and 232/269 (86.2%) Thy 4-5 patients were free of disease at the end of follow-up (p < 0.001). The time required to obtain 50% of patients in remission was 2 years in Thy 3 and 4 years in Thy 4-5 patients (p < 0.001). The most common histological type was the follicular variant of papillary thyroid carcinoma (FV-PTC) in Thy 3 patients (239/371, 64.4%) and the classic variant in Thy 4-5 patients (185/269; 68.8%). The FV-PTC had better prognostic features compared with the other PTC variants: T1 stage was observed in 133/277 (48.0%) FV-PTC patients and in 146/363 (40.0%) patients with the other variants (p < 0.001), N0 was present in 265/277 (96.0%) FV-PTC and in 290/363 (79.8%) patients with the other variants (p < 0.001). Overall, 267/277 FV-PTC patients (96.4%) and 324/363 patients (89.0%) with the other variants were free of disease (p < 0.0008) at the end of follow-up, and the time required to obtain 50% of patients in remission was 2 years in FV-PTC and 4.0 years in the other variants (p < 0.001). CONCLUSION: Patients with Thy 3 cytology have better outcomes of thyroid cancer compared with patients with Thy 4 or Thy 5 cytology, and indeterminate cytology is commonly associated with the less aggressive FV-PTC.

The role of limited posterior fossa craniectomy in the surgical treatment of Chiari malformation Type I: experience with a pediatric series.

OBJECT: Despite progress in the understanding of the causes and pathophysiology of Chiari malformation Type I (CM-I), definitive surgical treatment remains unresolved. Various techniques have been propounded over the years, but there is no general consensus on the most appropriate surgical management for this condition. The authors report their experience with the surgical treatment of 30 pediatric patients with CM-I. METHODS: The results obtained in 30 patients who underwent surgery for symptomatic CM-I with a purely extradural procedure were retrospectively reviewed. The patient age at operation ranged from 2 months to 16 years (mean 68 months). In 26 patients the CM-I occurred as an isolated disease, whereas in four a recognized bone anomaly involving the cranial base (achondroplasia) was observed. All patients underwent suboccipital craniectomy, which was accompanied by C-1 laminectomy in 22. In all cases a thick fibrous band at the level of foramen magnum was resected; in 11 children serial incisions of the outer layer of the dura mater were performed as well to expand the posterior fossa volume. The follow-up duration varied from a minimum of 12 months to 12.6 years (mean 4.7 years). The most frequent symptoms and signs were head and/or neck pain (56.7%), followed by vertigo (27.7%), upper-and lower-extremity weakness (20.0%), and ataxia (20.0%). Syringomyelia was noted in 12 patients (40.0%) on magnetic resonance (MR) images. Improvement in or resolution of clinical symptoms and signs was observed in all patients. However, only minimal or no modifications could be found in the position of cerebellar tonsils on postoperative MR images in most patients (only occasional improvement in tonsillar herniation), whereas syringomyelic cavitations reduced in size in half of the cases. Nevertheless, in only two patients was a reoperation necessary. CONCLUSIONS: In the authors' experience, suboccipital craniectomy and C-I laminectomy (eventually integrated by dural delamination) can represent an effective treatment for symptoms associated with CM-I.