Removal Of Cerebellopontine Angle Tumors Research Articles

Cerebellar Gray Matter Volume in Tinnitus.

Tinnitus is the perception of sound without an external source. The flocculus (FL) and paraflocculus (PFL), which are small lobules of the cerebellum, have recently been implicated in its pathophysiology. In a previous study, the volume of the (P)FL-complex correlated with tinnitus severity in patients that had undergone cerebellopontine angle (CPA) tumor removal. In this study, the relation between tinnitus and gray matter volume (GMV) of the (P)FL-complex, GMV of the other cerebellar lobules and GMV of the cerebellar nuclei is investigated in otherwise healthy participants. Data was processed using the SUIT toolbox, which is dedicated to analysis of imaging data of the human cerebellum. GMV of all cerebellar lobules and nuclei were similar between tinnitus and non-tinnitus participants. Moreover, no relation was present between tinnitus severity, as measured by the Tinnitus Handicap Inventory, and (P)FL-complex GMV, tonsil GMV, or total cerebellar cortical GMV. These results suggest that in otherwise healthy participants, in contrast to participants after CPA tumor removal, no relation between the GMV of neither the (P)FL-complex nor other cerebellar lobules and tinnitus presence and severity exists. These findings indicate that a relation only exists when the (P)FL-complex is damaged, for instance by a CPA tumor. Alternatively, it is possible that differences in (P)FL-complex GMVs are too small to detect with a voxel-based morphometry study. Therefore, the role of the (P)FL-complex in tinnitus remains to be further studied.

Clinical Application of Quantitative Nursing for Lower Cranial Nerves Injury after Cerebellopontine Angle Tumors

Objective: To retrospectively analyze the clinical utility of quantitative nursing measures of 10 cases of lower cranial nerves injury after cerebellopontine angle tumors surgery to provide the experience for improving the recovery rate and living quality of these patients. Methods: The clinical data of 10 cases of lower cranial nerves injury after cerebellopontine angle tumors surgery was analyzed. For problems such as dysphagia and dyspnea of these patients, the nursing care focused on strict monitoring, timely oxygen inhalation nursing, posture nursing, ventilator nursing, swallowing function training, etc. Results: After received quantitative care, 10 patients with lower cranial nerves injury after cerebellopontine angle tumors surgery were recovered well, and their symptoms such as dysphagia and dyspnea were gradually improved and safely discharged. Conclusion: Lower cranial nerves injury is one of the serious complications after removal of cerebellopontine angle tumors, which impacts the life and health of patients. Caregivers should accurately understand and analyze the symptoms, and quantitative and targeted nursing measures for posterior cranial nerves injury are helpful in the postoperative rehabilitation of patients and improve their living quality.

Surgical Treatment of Trigeminal Neuralgia Combined with Tumors of the Cerebellopontine Angle

Introduction . Trigeminal neuralgia (TN) develops because of demyelination in the entry zone of the trigeminal nerve root (TNR) into the brainstem, which is accompanied by ectopic and cross-excitation of the nerve impulses with paroxysms of facial pain. One of the causes of TN are tumors of the cerebellopontine angle (CPA), which have a direct or indirect effect on the TNR. The optimal surgical approach in such cases depends on the anatomical relationship between the TNR and the tumor and vascular structures. The aim of the study was to evaluate the relationship between the anatomical variants of the TNR and the outcomes of using various surgical methods to treat TN in CPA tumors. Materials and methods. We performed a retrospective analysis of 52 patients (38 women and 14 men aged 22–82 years) with TN and ipsilateral tumors of the CPA: 29 with apical petrous meningiomas, 11 with epidermoid tumors, 10 with vestibular schwannomas, 1 with haemangioma, and 1 with cavernoma. Results. Six variants of the anatomical relationships of the TNR to CPA tumors and the adjacent vascular structures were identified: where the TNR is completely surrounded by the tumor; where the tumor compresses and displaces the TNR; where the tumor is located inside the TNR; where the tumor, together with the blood vessel, compresses the TNR; where the tumor displaces the TNR towards the vessel; and where the tumor is not in contact with the TNR, but the TNR is compressed by the blood vessel. Displacement and deformation of the TNR by CPA tumors was found in 50 patients, and no direct contact between the TNR nerve fibers and the neoplasm was observed in 2 cases. The neurovascular conflict caused by arterial and venous vessels was identified in 16 subjects. The type of a vascular decompression technique depended on the degree of stretching and deformation of the TNR. Postoperative MRI confirmed the complete removal of CPA tumors in 51 patients, while minor epidermoid residue in the contralateral cerebellopontine angle cistern was found in only one subject. There were no fatalities after surgical interventions, and the postsurgical cranial nerve neuropathies were transient and regressed within 2–3 months. In 15 cases, hypoesthesia developed or worsened in the trigeminal nerve innervation zone, then disappeared within several weeks, and was not accompanied by a recurrence of TN. Facial sensitivity improved in 6 cases, who had not previously undergone any surgical manipulations of the TNR and its peripheral branches. Complete regression of TN in the immediate postoperative period was observed in 51 patients. A percutaneous radiofrequency trigeminal rhizotomy was performed in 1 subject with an epidermoid tumor, to eliminate the intense pain paroxysms that persisted for a week. No recurrent growth of CPA tumors or relapses of TN were observed during the subsequent follow-up period of 2–10 years. Conclusion. TN can be caused by direct compression and deformation of the TNR and brainstem by CPA tumors and vascular structures. A detailed examination of the entire length of the TNR after tumor removal is necessary to evaluate the neurovascular relationships. In cases of vascular compression of the TNR, various methods of microvascular decompression can be used to treat TN.

The relation between flocculus volume and tinnitus after cerebellopontine angle tumor surgery

PurposeChronic tinnitus is a common symptom after cerebellopontine angle (CPA) tumor removal. Sometimes, the tinnitus is gaze-modulated. In that case, patients can change the loudness or pitch of their tinnitus by ocular movements. During tumor removal by a retrosigmoid craniotomy, the cerebellar flocculus is manipulated by the surgical approach to access the tumor. The flocculus has been associated with tinnitus in rats, and is involved in eye-gaze control. This suggests that the flocculus may have a role in gaze-modulated tinnitus after CPA tumor removal. In order to investigate this hypothesis, the relation between the flocculus volume and the characteristics of postoperative tinnitus was studied. ResultsA single-center cohort of 51 patients completed a questionnaire after CPA tumor removal. The questionnaire asked for the effect of eye movements on tinnitus and included the Tinnitus Functional Index (TFI). Tinnitus was present in 36 patients (71% of 51), of which 29 (81% of 36) described gaze-modulation. The median TFI was 22 (range 0–85). A postoperative MRI-scan of sufficient quality was available in 34 cases. The volumes of the (para)flocculi ipsilateral and contralateral to the surgery, and the ratio of these volumes were similar between patients with and without tinnitus. The TFI correlated with the volume of both ipsi- and contralateral (para)flocculus (rs(23) = .516, p = .008 and rs(23) = .430, p = .032). The ipsilateral-to-contralateral volume ratio of the (para)flocculi volumes was significantly lower in patients that could modulate the loudness of their tinnitus by eye gaze, compared to patients that could not (t(23) = 3.337, p = .003). ConclusionsThe lack of a relation between flocculus volumes and the presence of tinnitus, combined with the significant correlation between tinnitus severity and flocculus volumes, suggests that the flocculus may not be the primary source of tinnitus, but is likely to mediate tinnitus severity. The reduced ipsi-to-contralateral volume ratio in patients with gaze-modulated tinnitus suggests that atrophy of the flocculus on the surgery side triggers cross-modal interactions leading to modulation of tinnitus.

Effect analysis of hypoglossal-facial neurorrhaphy using a predegenerated sural nerve autograft for peripheral facial paralysis

Objective To evaluate the treatment effects of hypoglossal-facial 'side’-to-side neurorrhaphy using a predegenerated sural nerve autograft for facial paralysis following tumor resection in cerebellopontine angle (CPA) area. Methods We followed up 48 patients who developed facial paralysis as a result of CPA tumor removal and underwent hypoglossal-facial 'side’-to-side neurorrhaphy using a predegenerated sural nerve autograft between June 2013 to February 2016 at Neurosurgery Department of Beijing Tiantian Hospital, Capital Medical University. Eight other patients who served as controls did not receive any repair treatment. Patients in both groups received rehabilitation exercises and their static and dynamic facial images were collected. Electrophysiological tests of the facial nerve were conducted including electromyography, motor nerve conduction and F wave. The patients' facial nerve functions were assessed according to House-Brackmann grading scale(H-B scale). The follow-up lasted 2-36 months with an average of (12.1±13.4) months. Results In the surgical treatment group, 24/48 patients were found postoperatively to have significant facial function improvement on H-B scale, 21/48 patients to have improvement, and 3/48 remained unchanged. In the control group, 1/8 patient was found to have significant facial function improvement on H-B scale, 2/8 had improvement and 5/8 remained unchanged associated with marked atrophy of paralyzed facial muscles. Significant difference was identified in the facial function improvement on H-B scale between the surgical treatment and control groups (P<0.01). The improvement of facial nerve function was most evident if the surgical repair treatment was performed within the 6 months after the onset of facial paralysis. Conclusions Hypoglossal-facial 'side’-to-side neurorrhaphy may effectively treat facial paralysis resulting from CPA tumor resection. Better recovery of facial nerve function could be achieved when the surgical treatment is performed within the 6 months after the onset of the facial paralysis. Key words: Central nervous system neoplasms; Cerebellopontine angle; Facial paralysis; Transplantation, autologous; 'Side’-to-side neurorrhaphy

Nerve crush but not displacement-induced stretch of the intra-arachnoidal facial nerve promotes facial palsy after cerebellopontine angle surgery.

Little is known about the reasons for occurrence of facial nerve palsy after removal of cerebellopontine angle tumors. Since the intra-arachnoidal portion of the facial nerve is considered to be so vulnerable that even the slightest tension or pinch may result in ruptured axons, we tested whether a graded stretch or controlled crush would affect the postoperative motor performance of the facial (vibrissal) muscle in rats. Thirty Wistar rats, divided into five groups (one with intact controls and four with facial nerve lesions), were used. Under inhalation anesthesia, the occipital squama was opened, the cerebellum gently retracted to the left, and the intra-arachnoidal segment of the right facial nerve exposed. A mechanical displacement of the brainstem with 1 or 3mm toward the midline or an electromagnet-controlled crush of the facial nerve with a tweezers at a closure velocity of 50 and 100mm/s was applied. On the next day, whisking motor performance was determined by video-based motion analysis. Even the larger (with 3mm) mechanical displacement of the brainstem had no harmful effect: The amplitude of the vibrissal whisks was in the normal range of 50°-60°. On the other hand, even the light nerve crush (50mm/s) injured the facial nerve and resulted in paralyzed vibrissal muscles (amplitude of 10°-15°). We conclude that, contrary to the generally acknowledged assumptions, it is the nerve crush but not the displacement-induced stretching of the intra-arachnoidal facial trunk that promotes facial palsy after cerebellopontine angle surgery in rats.

Rotational Pericranial Flap for Repair of Refractory Posterior Fossa Pseudomeningocele

Skull base approaches requiring retro- or translabyrinthine petrosectomy are frequently used for vestibular schwannoma and cerebellopontine angle tumor removal. One postoperative challenge is pseudomeningocele formation. Primary dural closure is often impractical due to dural shrinkage from cautery [1], desiccation, and the fact that pre-sigmoid dura is difficult to approximate with the retro/translabyrinthine approach. Synthetic, allograft, and autograft dural substitutes have been used with varying success rates. Pericranial autograft is a desirable substitute due to lack of immunogenicity, flexibility, and wide availability adjacent to posterior fossa lesions. Autologous fat has been used to pack the pre-sigmoid dural defect in order to effect a watertight seal. However, no method is completely effective.

Poszczepienne gruźlicze zapalenie ucha środkowego i jego powikłania – opis przypadku

IntroductionTuberculosis is a major problem of constant importance all over the world. Notably, in the developed countries it is due to immunosuppressive therapy and AIDS. Primary otological tuberculosis constitutes a very small share of cases of this disease. Moreover, the appearance of tuberculomas remains unique to even greater extent. Case reportClinical history of a patient who has already been infected tuberculosis for 60 years in result of the BCG vaccination. Ponto-cerebellum angle tumour appeared in his brain as complication ensuing the disease. The first therapeutic method used was based on antituberculous drugs, subsequent surgical intervention (cerebello-pontine angle tumor removal via translabirynthin approche) was necessary however. We suspected another cause of this lesion – cholesteatoma or facial nerve neurinoma. Correct diagnosis give only histopatological examination. Because of facial nerve palsy, facial nerve reconstruction was necessary (connection of n. VII and n. XII). ConclusionThis case reminds us that correct diagnosis of tuberculosis remains a serious problem despite the long experience and the development of diagnostics and treatment methods. Nowadays we observe the unusual clinical manifestations of the disease (e.g. such as ear pain, tinnitus, rapid hearing loss) more frequently.

Cerebellopontine angle tumors causing hemifacial spasm: types, incidence, and mechanism in nine reported cases and literature review

Although hemifacial spasm is usually caused by vascular compression around the root exit zone of the facial nerve, it is sometimes brought on by a cerebellopontine angle tumor. We reviewed and analyzed data from past experience with hemifacial spasm induced by cerebellopontine angle tumors. Nine patients of a total 2,050, who had presented with hemifacial spasms associated with cerebellopontine angle tumors between 1986 and 2009, were reviewed. Two vestibular schwannomas, five meningiomas, and two epidermoid tumors were included in this study. Hemifacial spasm occurred on the same side of the lesion in eight patients whereas it occurred on the opposite side of the lesion in one patient. With respect to the pathogenesis of hemifacial spasms, offending vessels were found in six patients, tumor encasement of the facial nerve in one patient, hypervascular tumor compression of the facial nerve without offending vessels in one patient, and a huge tumor compressing the brain stem and, thus, contralateral facial nerve compression in one patient. Hemifacial spasm was resolved in seven patients, whereas in two patients with a vestibular schwannoma and an epidermoid tumor, it improved transiently and then recurred in a month. Each type of tumor had different characteristics with respect to the induction of hemifacial spasm; therefore, it is suggested that neurosurgeons, who are planning surgeries both for the purposes of relieving hemifacial spasm and removal of cerebellopontine angle tumor, should thoroughly prepare appropriate approaches and specific dissecting strategies according to each causative lesion.

Image-guided surgical planning using anatomical landmarks in the retrosigmoid approach

The suboccipital lateral or retrosigmoid approach is the main neurosurgical approach to the cerebellopontine angle (CPA). It is mainly used in the treatment of CPA tumors and vascular decompression of cranial nerves. A prospective study using navigation registered with anatomical landmarks in order to identify the transverse and sigmoid sinuses junction (TSSJ) was carried out in a series of 30 retrosigmoid craniotomies. The goal of this study was to determine the accuracy of this navigation technique and to establish the relationship between the location of the asterion and the TSSJ. From March through November 2008, 30 patients underwent a retrosigmoid craniotomy for removal of CPA tumors or for surgical treatment of neurovascular syndromes. Magnetic resonance imaging (MRI) T1 sequences with gadolinium (FSPGR with FatSst, 1.5 T GE Signa) and frameless navigation (Vector vision, Brainlab) were used for surgical planning. Registration was performed using six anatomical landmarks. The position of the TSSJ indicated by navigation was the landmark to guide the craniotomy. The location of the asterion was compared with the position of the TSSJ. After craniotomy, the real TSSJ position was compared with the virtual position, as demonstrated by navigation. There were 19 cases of vestibular schwannomas, 5 petroclival meningiomas, 3 trigeminal neuralgias, 1 angioblastoma, 1 epidermoid cyst and 1 hemifacial spasm. In all cases, navigation enabled the location of the TSSJ and the emissary vein, with an accuracy flaw below 2 mm. The asterion was located directly over the TSSJ in only seven cases. One patient had a laceration of the sigmoid sinus during the craniotomy. Navigation using anatomical landmarks for registration is a reliable method in the localization of the TSSJ for retrosigmoid craniotomies and thereby avoiding unnecessary sinus exposure. In addition, the method proved to be fast and accurate. The asterion was found to be a less accurate landmark for the localization of the TSSJ using navigation.

Association Between Adipose Graft Usage and Postoperative Headache After Retrosigmoid Craniotomy

To evaluate the association between extradural abdominal fat graft placement for the closure of retrosigmoid craniotomy defects and postoperative headache. Retrospective chart review and analysis of patient questionnaires. Tertiary care academic medical center. One hundred twenty-seven patients who underwent retrosigmoid craniotomy between March 1999 and December 2006. All patients underwent retrosigmoid craniotomy for removal of cerebellopontine angle tumors and received either an abdominal fat graft closure or a standard wound closure. Using a written patient questionnaire, the presence or absence of both overall postoperative headache and specific postcraniotomy headache according to International Headache Society criteria was assessed. Of those patients who had postoperative headaches, the evaluation of headache severity was assessed using a standardized 5-point scale. Eighty-five patients returned completed questionnaires. Fifty-two respondents received adipose grafts; 33 did not. The adipose group demonstrated significantly less chronic postcraniotomy headaches (11.9% versus 30.3%; p < 0.05). Additionally, the adipose group described less severe headaches at all time frames studied with significant differences at 1 month (1.59 versus 2.29; p < 0.05) and 3 months (1.37 versus 2.06; p < 0.05) using the modified headache severity scale. When compared with standard wound closure without adipose grafting, use of an abdominal fat graft during retrosigmoid craniotomy wound closure is associated with both decreased incidence of chronic postoperative headache and decreased severity of postoperative headaches at all time intervals studied.

Influence of different approaches to the cerebellopontine angle on the function of the intermediate nerve

Surgery in the cerebellopontine angle (CPA) is a standard procedure at many centers. Outcome is focused mainly on preservation of hearing and facial function postoperatively. The nonmotor part of the facial nerve, the intermediate nerve, is nearly neglected nowadays. A retrospective study was designed, including a questionnaire that was sent to 178 patients who had undergone surgery between 2000 and 2004. Data were obtained in 156 cases. The questionnaire was divided into five parts assessing the presence of increased tearing, reduced tearing, salivation disturbances, increased nasal secretions, and abnormalities in taste. Finally, a self-assessment of patient symptoms was analyzed. Postoperatively, 70 patients (45%) experienced crocodile tears, whereas 62 (40%) had dry eyes. Disturbances in taste were noted in six patients (4%) preoperatively and in 52 patients (33%) after surgery. Increased nasal secretion was noted in 68 patients (44%) postoperatively. An analysis of the correlation between the surgical approach used and disturbances in the intermediate nerve revealed a strong tendency to a higher rate of symptoms following the middle fossa approach (p = 0.071, chi-square test). Data in this study demonstrate the clinical importance of nonmotor defects associated with CPA tumor removal. More than 50% of the patients in this study reported postoperative crocodile tears, dry eyes, nasal secretions, and/or taste disturbances. These sequelae may affect both short- and long-term postoperative quality of life to the same extent as deafness or transient facial paresis. The risk of injury seems to be higher after the middle fossa approach.

Facial Nerve Function Recovery after Removal of Cerebellopontine Angle Tumor

Facial Nerve Function Recovery after Removal of Cerebellopontine Angle Tumor

Intraoperative monitoring of cochlear function using distortion product otoacoustic emissions (DPOAEs) in patients with cerebellopontine angle tumors.

Intraoperative monitoring by distortion-product otoacoustic emissions reflects the cochlear function changes in the real-time domain during removal of cerebellopontine angle tumors. Cerebellopontine angle tumor surgery is associated with a significant risk of damaging internal auditory canal contents. Although monitoring facial nerve function intraoperatively has already been effectively developed, such efficacious monitoring of auditory function remains to be established. The aim of this study was to investigate the utility of distortion-product otoacoustic emissions for intraoperative monitoring of the cochlear function in humans during removal of cerebellopontine angle tumors. Continuous intraoperative monitoring of distortion-product otoacoustic emissions was performed in 20 of 62 patients undergoing surgical removal of cerebellopontine angle tumors. All of these 20 patients, who underwent the retrosigmoid approach, had distortion-product otoacoustic emissions present preoperatively. Depending on the amplitude and frequency band at which distortion-product otoacoustic emissions were present, monitoring was carried out at 2.0 to 6.0 kHz with primary stimulus tone amplitudes of 60 to 70 dB sound pressure level. In patients operated on for cerebellopontine angle tumors, various patterns of distortion-product otoacoustic emission amplitude reductions and recoveries were observed. Distortion-product otoacoustic emissions recorded from the basal part of the cochlea (i.e., high frequencies) changed earlier and more profoundly than those from the middle and apical sections (i.e., lower frequencies). In some cases, cochlear function was affected irreversibly as reflected by loss of distortion-product otoacoustic emissions. Microcoagulation of small vessels, tumor debulking, and compression or stretch of the internal auditory canal contents were found to be procedures affecting distortion-product otoacoustic emissions. The status of distortion-product otoacoustic emissions at the conclusion of tumor dissection correlated with postoperative hearing levels. Distortion-product otoacoustic emissions were used to monitor in the real-time domain auditory function during cerebellopontine angle tumor removal operations. The status of distortion-product otoacoustic emissions at the conclusion of the operations was related to postoperative hearing.

顔面神経舌下神経端側吻合術の経験

Hypoglossal-facial nerve anastomosis is a procedure for restoring facial nerve function after facial palsy caused by surgery for removal of cerebellopontine angle tumors. Classical hypoglossal-facial nerve anastomosis, however, sacrifices the hypoglossal nerve, inevitably causing hemitongue atrophy. To preserve hypoglossal nerve function, we tried hypoglossal-facial nerve side-to-end anastomosis for a 67-year-old woman who suffered from complete facial nerve palsy due to the removal of an acoustic neuroma. In this technique, the facial nerve in the mastoid cavity is exposed to the level of the external genu and then transected. The hypoglossal nerve is also exposed at the level of the axis and dissected as proximally as possible. One-third of the hypoglossal nerve is transected and the distal stump of the facial nerve is anastomosed without tension. In the postoperative stage, this technique provided facial reanimation without hypoglossal nerve dysfunction within one year. In conclusion, hypoglossal-facial nerve side-to-end anastomosis is a useful treatment for patients with long-standing facial palsy who do not want to have tongue dysfunction.

Medical treatment of headache after suboccipital acoustic tumor removal.

Suboccipital craniotomy is a frequently used surgical approach for removal of cerebellopontine angle (CPA) tumors. A frequently cited consequence, however, is the high incidence of postoperative headaches. Much has been written regarding prevention of these headaches, but little has been written of their treatment. The authors review their extensive experience in suboccipital tumor removal and the medical management of postoperative headache, highlighting the recent use of a regimen of divalproex sodium and verapamil. Retrospective chart review. The charts of a consecutive series of patients having suboccipital craniotomies for CPA tumors were reviewed. Presence, duration, and severity of headache were noted. Medical treatments and their effectiveness were also noted. Between 1980 and 1997, 228 patients underwent suboccipital craniotomy for removal of CPA tumors. Of these patients, 124 (54.4%) complained of headache. For 62 (27.2%) the headaches persisted for more than a year after surgery. Twenty-nine patients (12.7%) received no relief from any medication. Ten of these patients received a regimen of divalproex sodium and verapamil, with all patients obtaining significant relief. Headache is a significant problem with the suboccipital approach for acoustic tumor removal. The majority of patients that complain of headache can be adequately treated with nonsteroidal anti-inflammatory drugs (NSAIDs). If pain is unrelieved by NSAIDs, treatment becomes problematic. The authors' early experience with divalproex sodium/verapamil is encouraging and deserves further investigation as a treatment for these refractory cases.

Evolution of the management of hydrocephalus associated with acoustic neuroma.

The management of hydrocephalus in association with a cerebellopontine angle tumor is controversial. There is a widely held belief that initial therapy should always be directed toward treatment of hydrocephalus before definitive surgery. The potential problems of cerebrospinal fluid (CSF) shunting and drainage have to led to an evolution in the management of hydrocephalus at St. Vincent's Hospital. There is growing evidence that complete removal of cerebellopontine angle tumors will result in resolution of hydrocephalus without requiring other methods of CSF decompression. The authors present their experience of 14 patients with hydrocephalus found in a recent series of 104 consecutive cases of acoustic neuroma. This study has detected a significant correlation between hydrocephalus and increasing tumor size (P = .0234). The mean tumor size in this series was 3.8 cm. The series has also demonstrated that successful. safe, and complete tumor removal can be achieved without CSF drainage before surgery.

Functional and histological evaluation of the facial nerve in patients who have undergone hypoglossal-facial nerve anastomosis after removal of cerebellopontine angle tumors.

Facial nerve specimens removed from ten patients who underwent hypoglossal-facial nerve anastomosis for facial palsy following removal of cerebellopontine angle tumors were studied histologically. Facial nerve function prior to the anastomosis surgery and the degree of postoperative functional recovery were compared with the histological results. The recovery of facial palsy after the anastomosis surgery was excellent or satisfactory in nine patients and the endoneurium within the nerve fascicles was well-preserved. The recovery of facial palsy was poor in one patient who had severe fibrosis of the endoneurium. The histological and ultrastructural features of the facial nerve were closely related to the occurrence of facial palsy prior to tumor removal, the status of the nerve after tumor removal, and the interval between tumor removal and anastomosis surgery. Based on these histological and functional relationships, the timing and indications for anastomosis surgery are discussed.

Repair of facial nerve after removal of cerebellopontine angle tumors: a comparative study

The results of repair of 18 facial nerves were examined by means of a modified House-Brackmann grading system. Six were repaired by end-to-end anastomosis and 12 by nerve graft. The reliability of the simplified House-Brackmann grading system was also assessed, using the kappa statistic to analyze the agreement between pairs of observers who examined the function of 40 nerves in 37 patients. Facial nerves studied had been either preserved, repaired or grafted, or divided and treated by faciohypoglossal nerve anastomosis. One nerve was not treated. The grading system proved to be somewhat unreliable, with complete agreement between observers in only 25% of cases. Facial nerve repair produced a fair return of function in just under two-thirds of the cases. The ability of an examiner ignorant of the patient's history to assess from the end result how the nerve had been managed was also estimated. Observers showed little ability to decide correctly on the previous treatment of the nerve when the patient showed moderate dysfunction postoperatively. The implications of these findings for grading systems and for management of the facial nerve in acoustic nerve tumor surgery are discussed.

Hypoglossal-facial nerve anastomosis for facial nerve palsy following surgery for cerebellopontine angle tumors.

Hypoglossal-facial nerve anastomosis is one of the procedures frequently performed to restore function after facial palsy secondary to surgery for removal of cerebellopontine angle tumors. The published results of hypoglossal-facial nerve anastomosis have been variable, and there are still questions about the indications, timing, and surgical techniques for this procedure. The goals of the present retrospective analysis of 22 cases of hypoglossal-facial nerve anastomosis were to assess the extent of the functional recovery and to analyze the factors affecting this recovery. The 22 cases of complete facial palsy were gleaned from a series of 245 cases of cerebellopontine angle tumors treated surgically by one of the authors. Twenty patients had an acoustic neuroma (average size 3.5 cm), one patient had a petrous meningioma, and one patient had a facial neuroma. The average age of the patients was 47.3 years (range 19 to 69 years). The average interval from tumor surgery to hypoglossal-facial nerve anastomosis was 6.4 months (range 12 days to 17 months), and the average follow-up period after the procedure was 65 months. The results were graded as good, fair, poor, or failure according to a new method of classifying facial nerve function after hypoglossal-facial nerve anastomosis. The results were good in 14 cases (63.6%), fair in three (13.6%), and poor in four (18.2%); one (4.5%) was a failure. Good and fair results occurred with higher frequency in younger patients who were operated on within shorter intervals, although these relationships were not statistically significant. There were no surgical complications. Good or fair results were achieved in 17 (77.3%) of the 22 cases, and thus hypoglossal-facial nerve anastomosis is considered an effective procedure for most patients with facial palsy after surgery for cerebellopontine angle tumors.