Retromastoid Suboccipital Craniectomy Research Articles

DUMBBELL-SHAPED HYPOGLOSSAL SCHWANNOMA- A RARE CASE REPORT FROM NORTHEAST INDIA WITH REVIEW OF LITERATURE

Background: Hypoglossal nerve schwannomas are uncommon, benign, and slow growing tumors arising from Schwann cells of the peripheral nerve sheath. They are well-documented in adult population. To the best of our knowledge, dumbbell-shaped hypoglossal schwannomas are rare and only 40 cases have been described in literature till date. They are managed surgically which poses signicant challenges including preservation of facial nerve. A 57 year old female presented with periodic spells of headache Case presentation: , imbalance while walking, trouble swallowing, right-sided tongue atrophy, and chronic chest infection. She was subsequently diagnosed with right cerebello-pontine (CP) angle hypoglossal schwannoma with extracranial extension. The tumor was managed by surgery and was performed in two stages: Stage one involved right retromastoid-sub occipital (RMSO) craniectomy with gross total excision of the lesion in the right CP angle followed by endoscopic assisted transoral-transpharyngeal excision of the tumor in the neck. Post-surgery, the patient showed gradual improvement. She could walk independently, her headache sub-sided and she showed slow improvement of lower cranial nerve function. However, during last follow up, it was observed that atrophy on the right side of the tongue still persisted. This case highlights t Conclusion: he importance of accurate diagnosis and treatment of hypoglossal schwannoma. Complete surgical excision is the recommended treatment for hypoglossal schwannoma which subsequently lowers the risk of recurrence and gives a good prognosis

Surgical Management of Cerebellopontine Angle (CPA) Lipoma Presenting As Trigeminal Neuralgia: A Case Report

The report details an instance of a 35-year-old male, who came to our hospital with a two-year history of typical trigeminal neuralgia on the left side, predominantly in V2 and V3 dermatomes. The patient was started on medications, but pain could not be controlled by increasing doses and adjuvant medications over the last three months. A lesion was seen on the MRI in the left cerebellopontine angle (CPA) region, hyperintense on T1W and decreased on fat-suppressed imaging, characteristic of lipoma. Being an intractable case, surgery was offered to the patient. Following this, a left retromastoid suboccipital craniectomy was done, and lipoma was excised, decompressing the trigeminal nerve and relieving neuralgia symptoms. In the post-op period, the patient was completely pain-free, but he developed left-sided hearing loss and left facial palsy, Brackmann grade 4, which improved to Brackmann grade 3 on the three-month follow-up.

A giant anterior inferior cerebellar artery aneurysm in the guise of a cerebellopontine angle tumour: A case report and review of literature

Giant intracranial aneurysms, and aneurysms in the posterior circulation of the brain, are each rare entity when considered separately. It is more uncommon to find both coexisting. Aneurysms usually present when they rupture and haemorrhage, and for one to present with non-haemorrhagic symptoms, is rarer. The authors present an unusual case of a giant aneurysm of the anterior inferior cerebellar artery masquerading as a cerebellopontine angle tumour with cerebellar signs. The patient was treated with a retromastoid suboccipital craniectomy and microsurgical clipping and excision, with excellent results. A PubMed search of existing literature was carried out and reviewed and has been discussed.

Endoscopic Keyhole Retromastoid Approach in Neurosurgical Practice: Ant-Man's View of the Neurosurgical Marvel

Endoscopy is now a staple of any neurosurgical practice. The versatility of this approach and gratifying results has resulted in its increased popularity. The objective of this paper is to report our experience of managing various cerebellopontine angle (CPA) pathologies by endoscopic keyhole retromastoid suboccipital craniectomy (RMSO) approach. A retrospective review of the medical records of patients operated in our department by endoscopic keyhole RMSO approach was done along with a collection of relevant patient particulars. Forty-four patients (24 men and 20 women) were operated via an endoscopic keyhole RMSO approach for various lesions in and around the CPA. The craniectomy was of 2.0-2.5 cm in size. An endoscope was used as the sole visualizing tool throughout the procedure in all cases. Primarily 2 kinds of pathologies were approached: neoplasms, mostly benign (n= 33), and vascular loops (n= 11). The extent of excision in 33 tumor cases was gross total (n= 20), near total (n= 12), and subtotal (n= 1). In cases of a vascular loop, microvascular decompression was performed. Anatomic facial nerve preservation was ensured in all cases of vascular loops and in 30 tumor cases. Postoperative complications included new-onset/worsening of facial nerve paresis (n= 12, 27.3%), 9 of which improved in follow-up, transient facial hypoesthesia (n= 2, 4.5%), transient abducens paresis (n= 4, 9%), transient lower cranial nerve paresis (n= 3, 6.8%), pseudomeningocele (n= 1, 2.3%), cerebrospinal fluid leak with meningitis (n= 1, 2.3%) and operative site hematoma (n= 1, 2.3%) which required evacuation. Endoscopic keyhole RMSO approach is minimally invasive and yields an excellent outcome in the management of various CPA lesions.

Surgical excision of large-to-giant petroclival meningiomas focusing on the middle fossa approaches: The lessons learnt.

Petroclival meningiomas are based on or arising from the petro-clival junction in upper two-thirds of clivus, medial to the fifth cranial nerve. This study focuses on the surgical experience in resecting large-giant tumors >3.5 in size predominantly utilizing middle fossa approaches. 33 patients with a large or a giant petroclival meningioma (size >3.5 cm) were included. Clinical features, preoperative radiological details, operative findings, and postoperative clinical course at the follow-up visit were reviewed. Group A tumors (n = 17,51.5%) were sized 3.5cm-5cm, and Group B (n = 16,48.48%) tumors were of size >5 cm. Extent of resection was described as 'gross total' (no residual tumor), 'near total' (<10% residual tumor) and 'subtotal resection' (>10% residual tumor). Glasgow outcome scale (GOS) quantitatively scored postoperative neurological outcome (mean follow up: 35.77months; range 1-106 months). 25 (75.8%) patients had tumour extension into both supratentorial and infratentorial compartments. Extension into Meckel's cave (n = 25,75.8%), cavernous sinus (n = 17,48.4%], sphenoid sinus (n = 12,38.7%] and suprasellar area [12,38.7%] was often seen. In 31 (93.9%) patients, the tumor crossed the midline in the premedullary, prepontine, and interpeduncular cisterns. In 20 (60.6%) patients, the tumour extended below and posterior to the internal auditory meatus (IAM), while in 13 (39.4%) patients, the tumor was located above and anterior to the IAM. Kawase's approach was the most commonly used approach in 16 (48.48%) patients and resulted in maximum tumor resection. Other approaches included half-and-half (trans-Sylvian with subtemporal) [n = 6, 18.18%]; frontotemporal craniotomy with orbitozygomatic osteotomy [n = 1, 3%] and retromastoid suboccipital craniectomy (RMSO) [n = 7, 21.21%]. In 2 (6.06%) patients, staged anterior petrosectomy with RMSO; and, in 1, staged presigmoid with half-and-half approach was used. Gross total excision was achieved in 12 (36.36%), near-total excision in 15 (45.45%) and subtotal excision in 6 (18.18%) patients. 20 (60.6%) patients had a good functional outcome; 6 patients succumbed due to meningitis, pneumonitis, perforator injury or a large tumor recurrence. Half-and-half approach was used in tumors with middle and posterior cranial fossae components often extending to the suprasellar region. Kawase's anterior petrosectomy was utilized in resecting tumors with predominant posterior fossa component (along with a small middle fossa component) that was crossing the midline anterior to the brain stem, and mainly situated superomedial to the IAM. Tumors confined to the posterior fossa, that extended laterally and below the IAM were resected utilizing the RMSO approach. Occasionally, a combination of these approaches was used. Middle fossa approaches help in significantly avoiding morbidity by an early devascularisation and decompression of the tumor. In tumors lacking a plane of cleavage, a thin rim of capsule of tumor may be left to avoid brain stem signs.

Operative Complications of Microvascular Decompression for Hemifacial Spasm: Experience of 1548 Cases.

Although microvascular decompression (MVD) surgery is considered the gold standard treatment for hemifacial spasm, there are some MVD-related complications. We retrospectively reviewed 1548 patients with hemifacial spasm who underwent retromastoid suboccipital craniectomy with MVD from January 2009 to June 2013. All patients were followed for >2 years. Excellent and good results were 92.5% and 4.2%, respectively. Postoperative complications were recorded in 16.09% (n= 249). There was no MVD-related mortality. After MVD surgery, the most frequent complications were occipital sensory disturbance (7.3%), facial nerve palsy (9.7%), and hearing impairment (3.5%). Other complications were as follows: cerebrospinal fluid leakage (n= 24), poor healing wound (n= 14), lower cranial nerve palsy (n=12), wound infection (n= 4), and hemorrhage (n= 2). MVD operation is a safe treatment for hemifacial spasm. Facial nerve palsy is the most common MVD-related complication; preservation of the lesser occipital nerve during MVD surgery can decrease the rate of occipital sensory disturbance. Permanent or serious complications are comparatively rare in MVD surgery.

Factors Leading to Oro-Facial Herpetic Eruptions in Patients Undergoing Surgery for Vestibular Schwannoma

To study factors influencing oro-facial herpetic eruptions (HEs) in patients undergoing retromastoid suboccipital craniectomy for vestibular schwannomas (VS). A retrospective analysis of the prospectively collected database (from July 2014 to December 2015). Atotal of 87 patients underwent retromastoid suboccipital craniectomy for VS at our center. For the purpose of analysis the patient subset was divided into 2 groups, HE and non-HE. Pearson χ2 test or Fisher exact test were used to identify the factors. The overall incidence of postoperative HE was less than 1% (0.89%, 26 patients of 2916 cases); whereas after VS surgery, it was 20.69% (18 of 87). Demographic profiles of patients in the 2 groups were comparable. Average tumor size (with HE 3.19 ± 2× 0.67 cm, non-HE 3.38 ± 2× 1.07 cm), consistency, and laterality also were comparable between the 2 groups. Factors favoring development of postoperative HEs were large size (12 vs. 22, P= 0.013) and preoperative trigeminal nerve (CN V) involvement (9 of 18, 50%, P= 0.046). All patients developed HE in maxillary division of trigeminal nerve (V2), whereas involvement of ophthalmic (V1) and mandibular (V3) divisions were involved less commonly in combination with V2 (V2, 72.2%; V2+ V3, 22.2%; V1+ V2+ V3, 5.6%). The majority of the patients (55.56%) developed HE on postoperative day 3 and none beyond postoperative day 5. All patients responded to empirical oral acyclovir. The study highlights the relatively high incidence and factors associated with this rare but benign complication.

Postoperative complications of microvascular decompression for hemifacial spasm: lessons from experience of 2040 cases.

Microvascular decompression (MVD) is an effective and safe treatment option that offers the prospect of definitive cure for hemifacial spasm (HFS). However, there are potential risks of complications for MVD associated with retromastoid suboccipital craniectomy (RmSOC) and cranial nerves in particular. The purpose of this study was to identify clinical characteristics of possible complications after MVD for HFS and to establish appropriate management concept of these complications. We retrospectively reviewed medical records of 2040 patients who underwent RmSOC with MVD for HFS at Samsung medical center between January 1998 and March 2013. Of 2040 patients, 2027 were followed (99.4%). Of the 2027 patients, 1841 (90.8%) exhibited complete relief or minimal symptoms, and 113 (5.6%) reported improved spasm but had mild remnant symptoms. After operation, the most frequently developed complications were facial nerve palsy (8.19%), followed by middle ear effusion (4.90%) and hearing loss (3.63%). There were two cases of supratentorial subdural hemorrhage, three cases of infarction. MVD was found to be safe and effective treatment for HFS, in consistent with previous reports. Some of the complications such as facial nerve palsy, middle ear effusion, and hearing loss are relatively common. However, they have mild clinical courses that are usually transient.

Primary cerebello-pontine angle melanoma: a case report

Intra-cranial melanomas are commonly metastatic from primary melanoma elsewhere in the body. The primary occurrence of a melanoma in the brain parenchyma is rare. We report a case of 38 year aged woman who presented with deviation of left eye and headache. On imaging, a space occupying lesion was found in the left Cerebello-pontine angle and a preoperative diagnosis of meningioma was made. She underwent left retro-mastoid sub-occipital craniectomy and excision of a black vascular tumor. Histopathological examination revealed a melanoma which was confirmed with Immunohistochemical assay. Search for dermal, mucous and ocular lesions were negative. She received adjuvant radiation to the post- operative tumor bed to 5400cGy in 30 fractions using Intensity Modulated Radiation Therapy technique along with concurrent Temozolomide. She tolerated the treatment well and is symptom free 12 months after treatment. Primary Melanomas are rare lesions of the Cerebello-pontine angle and its radiological features, evaluation and management have been discussed. ------------------- Cite this article as : Ponni A, Jagannatha A, Gururajachar J, Harjani R, Koushik K, Subramanian N, Sowmya R, Varma R. Primary cerebello-pontine angle melanoma: a case report. Int J Cancer Ther Onco l 2014; 2 (3):020315. DOI : 10.14319/ijcto.0203.15

Staging in giant vestibular schwannoma surgery: A two consecutive day technique for complete resection in basic neurosurgical setups

ABSTRACT Introduction: Vestibular schwannomas constitute 8% of all intracranial tumors. A majority of vestibular schwannomas are sporadic and unilateral. Giant vestibular schwannomas are seen in our country due to the late diagnosis and long duration of symptoms before diagnosis. These giant schwannomas are challenging to manage as most of the patients are having brainstem compression. Materials and Methods: Twelve cases of a giant vestibular schwannoma were operated in our department between May 2011 and December 2012. Vestibular schwannomas with a maximal diameter of more than 4 cm were defined as a giant vestibular schwannoma. All the patients had a unilateral vestibular schwannoma. Performance status of all the patients were graded as per the Karnofsky performance score. Pre-operative assessment of 5th, 7th, 8th and lower cranial nerve status was done in all cases. Ventriculoperitoneal shunting was done pre-operatively in all cases. All patients were operated through retromastoid suboccipital craniectomy and retrosigmoid approach. These patients were operated in two stages in two consecutive days with overnight elective ventilation in ICU. Ultrasonic aspirator and nerve monitoring techniques were not used. Results: Giant acoustic schwannomas can be safely resected completely by a staged resection on two consecutive days without any increased morbidity or mortality. This technique may be employed to achieve complete resection of such lesions without deterioration of facial nerve function in institutions which do not have advanced facilities like nerve monitoring or ultrasonic aspirator.

Staging in giant vestibular schwannoma surgery: A two consecutive day technique for complete resection in basic neurosurgical setups.

Introduction:Vestibular schwannomas constitute 8% of all intracranial tumors. A majority of vestibular schwannomas are sporadic and unilateral. Giant vestibular schwannomas are seen in our country due to the late diagnosis and long duration of symptoms before diagnosis. These giant schwannomas are challenging to manage as most of the patients are having brainstem compression.Materials and Methods:Twelve cases of a giant vestibular schwannoma were operated in our department between May 2011 and December 2012. Vestibular schwannomas with a maximal diameter of more than 4 cm were defined as a giant vestibular schwannoma. All the patients had a unilateral vestibular schwannoma. Performance status of all the patients were graded as per the Karnofsky performance score. Pre-operative assessment of 5th, 7th, 8th and lower cranial nerve status was done in all cases. Ventriculoperitoneal shunting was done pre-operatively in all cases. All patients were operated through retromastoid suboccipital craniectomy and retrosigmoid approach. These patients were operated in two stages in two consecutive days with overnight elective ventilation in ICU. Ultrasonic aspirator and nerve monitoring techniques were not used.Results:Giant acoustic schwannomas can be safely resected completely by a staged resection on two consecutive days without any increased morbidity or mortality. This technique may be employed to achieve complete resection of such lesions without deterioration of facial nerve function in institutions which do not have advanced facilities like nerve monitoring or ultrasonic aspirator.

Posterior inferior cerebellar artery aneurysms: Anatomical variations and surgical strategies

Context:Posterior inferior cerebellar artery (PICA) aneurysms are associated with multiple anatomical variations of the parent vessel. Complexities in their surgical clipping relate to narrow corridors limited by brain-stem, petrous-occipital bones, and multiple neurovascular structures occupying the cerebellomedullary and cerebellopontine cisterns.Aims:The present study focuses on surgical considerations during clipping of saccular PICA aneurysms.Setting and Design:Tertiary care, retrospective study.Materials and Methods:In 20 patients with PICA aneurysms, CT angiogram/digital substraction angiogram was used to correlate the site and anatomical variations of aneurysms located on different segments of PICA with the approach selected, the difficulties encountered and the final outcome.Statistical Analysis:Comparison of means and percentages.Results:Aneurysms were located on PICA at: vertebral artery/basilar artery (VA/BA)-PICA (n=5); anterior medullary (n=4); lateral medullary (n=3); tonsillomedullary (n=4); and, telovelotonsillar (n=4) segments. The Hunt and Hess grade distribution was I in 15; II in 2; and, III in 3 patients (mean ictus-surgery interval: 23.5 days; range: 3-150 days). Eight patients had hydrocephalus. Anatomical variations included giant, thrombosed aneurysms; 2 PICA aneurysms proximal to an arteriovenous malformation; bilobed or multiple aneurysms; low PICA situated at the foramen magnum with a hypoplastic VA; and fenestrated PICA. The approaches included a retromastoid suboccipital craniectomy (n=9); midline suboccipital craniectomy (n=6); and far-lateral approach (n=5). At a follow-up (range 6 months-2.5 years), 13 patients had no deficits (modified Rankin score (mRS) 0); 2 were symptomatic with no significant disability (mRS1); 1 had mild disability (mRS2); 1 had moderately severe disability (mRS4); and 3 died (mRS6). Three mortalities were caused by vasospasm (2) and, rupture of unclipped second VA-BA junctional aneurysm (1).Conclusions:PICA aneurysms may present with only IVth ventricular blood without subarachnoid hemorrhage. PICA may have multiple anomalies and its aneurysms may be missed on CT angiograms. Surgical approach is influenced by VA-BA tortuosity and variations in anatomy, location of the VA-BA junction and the PICA aneurysm relative to the brain-stem, and the pattern of collateral supply. The special category of VA-PICA junctional aneurysms and its management; and, the multiple anatomical variations of PICA aneurysms, merit special surgical considerations and have been highlighted in this study.

Microvascular decompression for hemifacial spasm due to four offending vessels: a case report

A 65-year-old woman presented with left facial involuntary movement and facial palsy for eight years. Brain magnetic resonance image (MRI) and magnetic resonance angiography (MRA) revealed multiple vascular compression of facial nerve root exit zone (REZ). Standard retromastoid suboccipital craniectomy and arachnoid dissection were performed. Right vertebral artery (VA), left VA, left anterior inferior cerebellar artery (AICA), and left posterior inferior cerebellar artery (PICA) compressed the facial nerve in that order. The offending vessels were dissected away from the facial nerve and transposed sequentially. Teflon was interposed between the arteries and the nerve. Electrophysiological monitoring showed disappearance of the abnormal hemifacial spasm response during the operation. The offending vessels were right VA, left VA, left AICA, and left PICA. Postoperatively, the patient's involuntary movement was completely resolved. We report a rare case of hemifacial spasm caused by four offending vessels that was treated by microvascular decompression (MVD) with wide arachnoid dissection.

A rare case of extradural neurenteric cyst with supratentorial and infratentorial extension

Dear Editor, Neurenteric cysts are rare benign endodermal lesions of the central nervous system like the Rathke cleft and colloid cysts. Intracranial neurenteric cysts are rare, with less than 100 cases reported in literature, most of which are found in the posterior fossa. We discuss a rare case of an extradural neurenteric cyst with supratentorial and infratentorial extension, and review the embryogenesis and differential diagnosis based on imaging and histopathological features. A 20-year male presented with suboccipital headache and painless, progressive diminution of vision of both eyes of 2 months’ duration. He was counting fingers close to face, and bilateral papilledema was noted. Evaluation with CT scan and MRI of the brain revealed an extradural lesion in the left posterior fossa with extension into the temporal region across the tentorium (Fig. 1a). He underwent a left retromastoid suboccipital craniectomy which was extended into the temporal region. The cyst was completely extradural in location, easily separable from the overlying bone and underlying duramater, except in the region over the transverse sinus where it was adherent to the duramater. Near total excision of the cyst wall was performed, leaving behind a part of the wall which was not separable from the duramater overlying the transverse sinus. The cyst contained thick, yellowish fluid (Fig. 1b), which was sterile on pyogenic culture with no cholesterol crystals or macrophages on microscopic examination. The patient had an uneventful post operative recovery period. At 6 months follow-up, his vision in the right eye improved to finger counting at 2 m, while that in the left eye remained unchanged. On fundoscopy, bilateral optic atrophy was noted. CT scan performed at 6 months showed no evidence of recurrence of the lesion (Fig. 1d). Histopathology sections showed a cystic lesion lined by a single layer of ciliated tall columnar epithelium (Fig. 1e). There was focal squamous metaplasia. Other connective tissue or glial elements were not identified. Immunohistochemistry with cytokeratin showed intense cytoplasmic positivity (Fig. 1f) in lining cells, whereas glial fibrillary acidic protein was negative (Fig. 1g). The precise embryological origin of the intracranial neurenteric cyst is not known. Since the endoderm does not extend cranially farther than the clivus, the possible explanation for an intracranial neurenteric cyst is displacement of the endoderm from its normal location (nasopharyngeal, respiratory tract, or intestinal tract) to an ectopic position in the embryo. Harris et al. has attributed the occurrence of posterior fossa neurenteric cyst to disturbance in early gastrulation after the onset of primitive streak regression [3]. Graziani et al. proposed that neurenteric cyst, colloid cyst, and Rathke cleft cyst originate from Seessel’s pouch, an endoderm diverticulum found behind esophageal membrane that usually regresses and disappears [2]. The evidence in support of this theory is that intracranial neurenteric cysts are not associated with other developmental malformations unlike spinal neurenteric cysts that are associated with occult spinal dysraphisms. The authors declare that this case report has not been presented at any conference or accepted for publication in any journal before. R. S. Reddy (*) :M. Vijayasaradhi Department of Neurosurgery, Nizam’s Institute of Medical Sciences, Hyderabad, Andhra Pradesh, India 500082 e-mail: rajesh_jipmer@rediffmail.com

Management of anterior inferior cerebellar artery aneurysms: an illustrative case and review of literature

Aneurysms of the anterior inferior cerebellar artery (AICA) are relatively rare among intracranial aneurysms. They can occur in 1 of 3 regions of the AICA: 1) craniocaudal (high or low riding), 2) mediolateral-premeatal (proximal), and 3) meatal-postmeatal (distal). The management strategies for treatment differ according to the location and configuration of the aneurysm. The existing body of neurosurgical literature contains articles published on aneurysms arising from the AICA near the basilar artery (BA), intracanalicular/meatal aneurysms, and distal AICA. Several therapeutic options exist, encompassing microsurgical and endovascular techniques. The authors describe a case of treatment involving a large BA-AICA aneurysm approached via exposure of the presigmoid dura using a retromastoid suboccipital craniectomy and partial petrosectomy. Treatment of these lesions requires detailed knowledge of the anatomy, and an anatomical overview of the AICA with its arterial loops and significant branches is presented, including a discussion of the internal auditory (labyrinthine) artery, recurrent perforating arteries, subarcuate artery, and cerebellosubarcuate artery. The authors discuss the various surgical approaches (retromastoid, far lateral, subtemporal, and transclival) with appropriate illustrations, citing the advantages and disadvantages in accessing these AICA lesions in relation to these approaches. The complications of these different surgical techniques and possible clinical effects of parent artery occlusion during AICA surgery are highlighted.

NOVEL SURGICAL TREATMENT OF A TRANSVERSE-SIGMOID SINUS ANEURYSM PRESENTING AS PULSATILE TINNITUS

Pulsatile tinnitus is a relatively common, potentially incapacitating condition that is often vascular in origin. We present a case of disabling pulsatile tinnitus caused by a transverse-sigmoid sinus aneurysm that was surgically treated with self-tying U-clips (Medtronic, Inc., Memphis, TN). We also review the literature and discuss other described interventions. A 48-year-old woman presented with a 5-year history of progressive pulsatile tinnitus involving the right ear. Her physical examination was consistent with a lesion that was venous in origin. Angiography demonstrated a wide-necked venous aneurysm of the transverse-sigmoid sinus that had eroded the mastoid bone. The patient underwent a retromastoid suboccipital craniectomy to expose the aneurysm and surrounding anatomy. The aneurysm dome was tamponaded and the aneurysm neck was coagulated until the dome had shrunk to a small remnant. The linear defect in the transverse sigmoid junction was then reconstructed with a series of U-clips and covered with Gelfoam hemostatic sponge (Pfizer, Inc., New York, NY). The patient awakened without neurological deficit and with immediate resolution of her tinnitus. A postoperative angiogram demonstrated obliteration of the aneurysm, with minimal stenosis in the region of the repair and good flow through the dominant right transverse-sigmoid junction. This technical case report describes a novel definitive surgical treatment of venous sinus aneurysms. This technique does not necessitate long-term anticoagulation, has a low likelihood of reintervention, and provides immediate resolution of pulsatile tinnitus.

Multiple anterior inferior cerebellar artery aneurysms associated with an arteriovenous malformation: case report

Background Multiple aneurysms of the proximal part of the anterior inferior cerebellar artery (AICA) associated with a distal arteriovenous malformation (AVM) are extremely rare lesions. Methods A 52-year-old man was admitted because of sudden headache. Neurological examination revealed ataxia. Computed tomography scan showed a right cerebellar and subarachnoid hemorrhage. Vertebral angiograms demonstrated 3 small aneurysms at the proximal part of the AICA and distal AVM. Results A right-sided lateral retromastoid suboccipital craniectomy was performed. We observed strangulation and obliteration at the AICA due to multiple clipping for aneurysms. Thus, aneurysms could not be clipped. At 11 years after bleeding, vertebral angiograms showed that 3 aneurysms had slightly enlarged but the AVM remained unchanged. To date, the patient is still doing well except for dizziness. Conclusion This association is very rare at the AICA level, and definitive treatment of this association is sometimes complex.

A technique for dural repair following retromastoid suboccipital craniectomy

A bstract The authors describe a simple technique used to achieve a water-tight closure of the dura mater during suboccipital craniectomy.

Surgical treatment of jugular foramen schwannomas.

Sixteen patients with schwannomas of the jugular foramen were operated on in the Department of Neurosurgery of the Nordstadt Hospital in Hannover, Germany, between 1986 and 1992. Patients with neurofibromatosis were excluded. The records of the 16 patients were retrospectively reviewed. There were five women and 11 men (mean age 43 years) with a symptom duration ranging from 6 months to 20 years (mean 5 years). The predominant symptoms were hearing loss, hoarseness, and cerebellar symptoms. Computerized tomography (CT), magnetic resonance (MR) imaging, and angiography were performed in all 16 patients. Depending on the radiological and surgical features, the tumors were classified into four types: Type A, a tumor primarily at the cerebellopontine angle with minimal enlargement of the jugular foramen (eight cases); Type B, a tumor primarily at the jugular foramen with intracranial extension (two cases); Type C, a primarily extracranial tumor with extension into the jugular foramen (one case); and Type D, a dumbbell-shaped tumor with both intra- and extracranial components (five cases). A retromastoid suboccipital craniectomy was performed for Type A tumors, and a combined cervical-mastoidectomy for Types B, C, and D. Total tumor removal was achieved in all cases. There was no operative mortality. Postoperative complications were cerebrospinal fluid leakage in one patient and mastoiditis in two patients. The follow-up period ranged from 12 to 42 months (mean 22 months). All patients were alive at the last follow-up review, and CT and/or MR imaging showed no tumor recurrence.

Posterior Inferior Cerebellar Artery Dissecting Aneurysm presenting with Wallenberg's Syndrome

A 37-year-old nonhypertensive male suddenly experienced mild left suboccipital pain while driving. In addition to neck pain persisting for 5 days, he began to experience vertigo and cold sensation in the right hand. On admission the patient was alert and cooperative. He had no neck stiffness. Clinical examination revealed typical Wallenberg's syndrome. Routine laboratory investigations were all normal. A computed tomographic scan revealed no abnormalities. Left vertebral angiography showed a fusiform shadow at the proximal posterior inferior cerebellar artery (PICA), but neither double lumen nor pooling of the contrast medium in the venous phase was observed. Left retromastoid suboccipital craniectomy disclosed no evidence of recent subarachnoid hemorrhage. The proximal PICA was enlarged for a distance of 1 cm, beginning 5 mm distal to its vertebral origin. Both the enlarged portion and a segment just distal to it were purplish-red. It was diagnosed as a dissecting aneurysm of the PICA with distal extension. Proximal ligation of the PICA was successful, and the patient was discharged with no deficits. It must be emphasized that vertebrobasilar aneurysms should be carefully ruled out in patients with Wallenberg's syndrome, particularly those who are fairly young and not predisposed to hypertension or arteriosclerosis, and in whom the initial symptom is unusual headache.