1/149. Delayed intracranial abscess after acoustic neuroma surgery: a report of two cases.OBJECTIVE: The use of antibiotics before and after surgery has made infectious complications of neurotologic surgery rare. The neurosurgical literature cites a rate of postoperative meningitis between 1% and 2% for "clean" cases and 1.5% to 2.5% for "clean contaminated" cases, such as cerebrospinal fluid contact with the middle ear or mastoid. Reports of infections after neurotologic procedures are rare in the otologic literature. In this report, two patients with brain abscess occurring in a delayed fashion after surgery are described. STUDY DESIGN: The study design was a retrospective chart review and case report. SETTING: The study was conducted at a tertiary referral center. RESULTS: Patient 1 underwent a suboccipital craniotomy for removal of an acoustic neuroma and had an uneventful postoperative recovery. Three months after surgery, he reported mild unsteadiness. Examination revealed mild ataxia, which led to repeat magnetic resonance imaging (MRI) and a diagnosis of cerebellar abscess. Patient 2 underwent translabyrinthine removal of an acoustic neuroma complicated by postoperative pseudomonas aeruginosa meningitis, which responded promptly to intravenous antibiotics. Fifteen months after surgery, he visited a neurologist after having a seizure and was treated with anticonvulsants. After a second episode of seizure, imaging studies showed a temporal lobe abscess. CONCLUSIONS: The signs of intracranial abscess may be subtle and can occur weeks or months after surgery, requiring vigilance and a high index of suspicion for diagnosis. A change in postoperative symptoms after acoustic neuroma surgery should signal further investigation using MRI with gadolinium.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
2/149. Persistent trigeminal neuralgia after removal of contralateral posterior cranial fossa tumor. Report of two cases.BACKGROUND: Contralateral trigeminal neuralgia as a false localizing sign in patients with posterior cranial fossa tumors is rare. Persistent contralateral trigeminal neuralgia after removal of the posterior fossa expanding lesion with microsurgical exploration of the affected trigeminal nerve root has been described in only a few reports. Displacement of the brainstem and the trigeminal nerve root, arachnoid adhesions, and vascular compression of the nerve root entry zone have been reported as causes of persistent contralateral trigeminal neuralgia. methods: One patient developed transformation of the contralateral constant burning facial pain into trigeminal neuralgia after removal of a posterior fossa meningioma. A typical right-sided tic douloureux in our second patient did not disappear after removal of a left acoustic neurinoma. CT scan revealed brainstem displacement to the side of trigeminal neuralgia. Microsurgical exploration in both cases demonstrated the squeezed and distorted trigeminal nerve root and displaced brain stem with no vascular involvement. Both patients underwent partial trigeminal rhizotomy for pain control. RESULTS: Complete disappearance of the trigeminal neuralgia was evident in both cases with postoperative facial sensory loss. The postoperative course in the first case was uneventful; the second patient died from purulent meningoencephalitis. CONCLUSION: Persistent contralateral trigeminal neuralgia after removal of a posterior fossa tumor is caused by distortion of the fifth nerve root by the displaced brainstem. Partial trigeminal rhizotomy can be performed for alleviation of facial neuralgic pain in cases without neurovascular compression.- - - - - - - - - - ranking = 4keywords = brain (Clic here for more details about this article) |
3/149. facial nerve grafts: from cerebellopontine angle and beyond.OBJECTIVES: To review the outcomes from facial nerve cable grafting in a variety of pathologic conditions and to determine the possible causes of poor facial function after facial nerve grafting. STUDY DESIGN: A retrospective review of patients undergoing facial nerve grafts through a neurotologic procedure. SETTING: This study was performed at a university-based tertiary referral center. patients: All 27 patients undergoing a neurotologic procedure that required a facial nerve graft from 1982 to 1997 were reviewed. Fourteen patients had grafts from the facial nerve stump at the brainstem. INTERVENTIONS: All patients had facial nerve function determined by the senior neurotologist and through use of historical data and photographs. MAIN OUTCOME MEASURE: A facial nerve repair recovery score was developed for facial nerve transection and repair. The House-Brackmann scale was found to be inappropriate for transected and repaired nerves. RESULTS: Facial function was found in 23/25 (92%) patients with at least 8 months follow-up. Statistical analysis revealed no significant correlation between graft length and recovery score. patients who had the nerve grafted to a site distal to the meatal foramen had a mean outcome that was nearly one grade level better than those with an anastomosis proximal to the meatal foramen (i.e., at the brainstem), but this did not reach statistical significance. CONCLUSIONS: facial nerve grafting is an effective way of restoring facial motor function. A new facial recovery grading scale is proposed for repaired or grafted facial nerves.- - - - - - - - - - ranking = 2keywords = brain (Clic here for more details about this article) |
4/149. Miniaturised ultrasonic aspiration handpiece for increased applicability.OBJECTIVE: At present, ultrasonic aspiration is routinely used in several fields of surgery, especially in brain and spinal micro-surgery for tumour removal. In order to broaden the access to difficult surgical sites, it is important to design highly miniaturised but still efficient handpieces. The internal resonant system, always made of high-grade materials, must be optimally dimensioned. Normally this is done semi-empirically, by successively improving the design during many iterative test steps. This method however involves several additional difficulties when the degree of miniaturisation increases. For example, small transducer weights exacerbate heat-dissipation problems and make design optimisation important. methods: To resolve these problems we have produced modelling software that makes it possible to simulate and automatically tune each individual interacting section of the design before it is actually manufactured, thereby assuring optimal efficiency. RESULTS: Using a new mini-handpiece, designed via the software, two cases of dissection of acoustic neurinomas were successfully performed. CONCLUSION: Using conventional physical steps for improving ultrasonic aspiration handpieces, several problems arise when the grade of miniaturisation increases, due to increasing demands. We have designed computer software for handpiece simulation. Using this model it has been possible to manufacture a highly efficient miniaturised handpiece.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
5/149. diagnosis and documentation of central nervous system dysfunctions with craniocorpography after surgical removal of acoustic neurinomas.Among other tests, craniocorpography (CCG) was performed in 21 patients after acoustic neurinoma surgery. After surgery, 17 patients (81%) had a developing vestibular compensation or an already normal CCG pattern; 3 patients (14%) had signs of persisting central nervous system dysfunction, either localized to the brain stem or in combination with a cerebellar dysfunction, and 1 patient showed a delayed but sufficient compensation after removal of a neurinoma that compressed central nervous system structures. brain stem and cerebellar dysfunctions caused by tumor compression demonstrated a better vestibular compensation than dysfunctions caused by surgical manipulation, despite no evidence of cerebellar alteration. As an adjunct to complete neuro-otologic and neurologic examinations CCG could become a useful tool in the topodiagnosis of central nervous system dysfunctions after acoustic neurinoma surgery and therefore in the documentation and follow-up process of these patients.- - - - - - - - - - ranking = 10.83412440751keywords = brain, central nervous system, nervous system (Clic here for more details about this article) |
6/149. meningioma of the internal auditory canal with extension into the vestibule.Meningiomas account for approximately 18 to 19 per cent of all brain tumours. Although they can arise in numerous locations, meningiomas of the internal auditory canal (IAC) are rare. Most tumours that originate in the IAC are schwannomas of the VIIIth cranial nerve (acoustic neuromas). We report a case of a meningioma which appears to originate from the IAC and extends into the vestibule. The clinical findings and the radiographical features of meningiomas of the IAC are similar to those of acoustic neuromas. Pre-operative differentiation between acoustic neuromas and meningiomas of the IAC may be difficult.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
7/149. Current surgical results of retrosigmoid approach in extralarge vestibular schwannomas.BACKGROUND: Vestibular schwannomas (VS) are common tumors that can be cured; they are reported to comprise 6 approximately 8% of all intracranial tumors. The primary objective in the surgery of extralarge VS is total removal of the tumor mass while preserving the facial nerve. In extralarge tumors, complete excision of the tumor carries a significant risk of injuring the facial nerve and adjacent vital brain structures. The authors are reporting the techniques and results of operation on extralarge VS. methods: The material consisted of 30 patients during the last 6 years with surgically treated VS that had a maximal extrameatal diameter exceeding 4 cm. Suboccipital craniotomy and tumor removal was performed with patients in the lateral position. Results and complications of the surgical technique will be reviewed. RESULTS: Average age of patients was 45.2 years; there was a slight female predominance (1.5:1). Size of the mass ranged from 41 to 70 mm; all were removed by the retrosigmoid transmeatal approach. Peritumoral edema on MRI was seen in 50% (15/30). Total removal was achieved in 73.3% (22/30) with no significant relationship to peritumoral edema. In the cases of total removal, the facial nerve preservation rate was 86.4% (19/22). There was no mortality. Surgical complications were hemorrhage and CSF leakage in 1 case (3%) and 8 cases (26.7%), respectively, but in most of these cases, conservative treatment was adequate. In patients in whom anatomic preservation of the facial nerve was achieved, facial nerve function improved progressively within a year. In all cases except for one with gait disturbance, a good outcome was achieved.CONCLUSIONS: Our surgical techniques, including the prediction of facial nerve displacement, not using retractors, and replacement of bone, contributed to good surgical results in a series of extralarge VS.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
8/149. Acoustic schwannoma and arachnoid cyst colocated in the cerebellopontine angle--case report.A 50-year-old female presented with a right acoustic schwannoma colocated with a cerebellopontine angle arachnoid cyst. The arachnoid cyst was distinct from the arachnoid cap surrounding the acoustic schwannoma. Initial excision of the arachnoid cyst created the space required to excise the schwannoma. The acoustic schwannoma had surprisingly dense adhesions to the brainstem, probably due to the constant pressure exerted by the cyst displacing the tumor towards the brainstem. The acoustic schwannoma was excised by meticulous dissection. Such a coexisting lesion should be suspected when a large cystic collection surrounds an acoustic schwannoma. Initial excision of the arachnoid cyst will prevent excessive cerebellar retraction.- - - - - - - - - - ranking = 2keywords = brain (Clic here for more details about this article) |
9/149. Lesions of the internal auditory canal and cerebellopontine angle in an only hearing ear: is surgery ever advisable?OBJECTIVE: To define the indications for surgery in lesions of the internal auditory canal (IAC) and cerebellopontine angle (CPA) in an only hearing ear. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. patients: Seven patients with lesions of the IAC and CPA who were deaf on the side opposite the lesion. Five patients had vestibular schwannoma (VS), and one each had meningioma and progressive osseous stenosis of the IAC, respectively. The opposite ear was deaf from three different causes: VS (neurofibromatosis type 2 [NF2]), sudden sensorineural hearing loss, idiopathic IAC stenosis. INTERVENTION(S): Middle fossa removal of VS in five, retrosigmoid resection of meningioma in one, and middle fossa IAC osseous decompression in one. MAIN OUTCOME MEASURE: Hearing as measured on pure-tone and speech audiometry. RESULTS: Preoperative hearing was class A in four patients, class B in two, and class C in one. Postoperative hearing was class A in three patients, class B in one, class C in two, and class D in one. CONCLUSIONS: Although the vast majority of neurotologic lesions in an only hearing ear are best managed nonoperatively, in highly selected cases surgical intervention is warranted. Surgical intervention should be considered when one or more of the following circumstances is present: (1) predicted natural history of the disease is relatively rapid loss of the remaining hearing, (2) substantial brainstem compression has evolved (e.g., large acoustic neuroma), and/or (3) operative intervention may result in improvement of hearing or carries relatively low risk of hearing loss (e.g., CPA meningioma).- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
10/149. The interdisciplinary approach to oral, facial and head pain.BACKGROUND: Chronic oral, facial and head pain is a common clinical problem, and appropriate diagnosis and management are a challenge for health care professionals. patients often will first seek the care of dentists because of the pain's localization in the oral cavity and surrounding structures. This article emphasizes the importance of establishing accurate diagnoses and conducting appropriate triage of the patient with complex orofacial pain. CASE DESCRIPTIONS: The authors present two case reports illustrating the complex nature of oral, facial and head pain, and the potential and actual pitfalls in management of this condition. These representative cases demonstrate how orofacial pain--which appears to be localized in the peripheral dental and oral structures--can have extremely complex etiologies involving other anatomical structures, the central nervous system and psychological factors. The reports point to the need for the expertise of a number of specialists in such cases. CLINICAL IMPLICATIONS: If the symptoms and clinical findings do not appear to be consistent with typical oral disease, or if standard treatments do not alleviate the pain, the dental clinician must consider other, more complex orofacial pain diagnoses. The dental professional should not hesitate to make referrals to key specialists or to members of an interdisciplinary team at a pain treatment center who have the expertise to appropriately diagnose and manage chronic oral, facial and head pain.- - - - - - - - - - ranking = 1.4048749153586keywords = central nervous system, nervous system (Clic here for more details about this article) |
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