The impact of mental health on health-related quality of life in patients with NF2-related Schwannomatosis.

NF2-related schwannomatosis (NF2-SWN) is a rare genetic disorder and is associated with progressive morbidities. This study aimed to investigate the relationship between NF2-SWN disease severity, health-related Quality of Life (QoL), and mental health aspects of patients. Standardised questionnaires assessing mental health problems (symptoms of depression, anxiety, and somatic burden), psychological factors (resilience, loneliness, and personality functioning), and health-related QoL were administered to 97 patients with NF2-SWN. The results of these questionnaires were compared with physician-rated disease severity. Questionnaires were completed by 77 patients. Physician-rated disease severity scores were available for 55 patients. NF2-SWN patients showed a high prevalence of clinically relevant symptoms of depression (30%), anxiety (16%), and somatic burden (32%). Almost all variables showed moderate to high correlations with NF2-SWN-related QoL. NF2-SWN-related QoL was associated with physician-reported disease severity (r = 0.614). In the stepwise hierarchical linear regression analysis, a significant model with four predictors (disease severity type, depression symptoms, personality functioning, and gender) explained 64% of the variance in NF2-SWN-related QoL. Our results showed a strong association between NF2-SWN-related QoL and depression symptoms. Moreover, personality functioning is an important influencing factor, representing a modifiable construct that can be targeted by prevention programs or psychotherapy.

Trends in frailty in brain tumor care during the COVID-19 pandemic in a nationwide hospital network in Germany.

PURPOSE: Among brain tumor patients, frailty is associated with poor outcomes. The COVID-19 pandemic has led to increased frailty in the general population. To date, evidence on changes in frailty among brain tumor patients during the pandemic is lacking. We aimed to compare frailty among brain tumor patients in Germany during the COVID-19 pandemic to the pre-pandemic era and to assess potential effects on brain tumor care. METHODS: In this retrospective observational study, we compared frailty among brain tumor patients hospitalized during the COVID-19 pandemic in years 2020 through 2022 to pre-pandemic years 2016 through 2019 based on administrative data from a nationwide network of 78 hospitals in Germany. Using the Hospital Frailty Risk Score (HFRS), frailty was categorized as low, intermediate, or high. We examined changes in frailty, patient demographics, the burden of comorbidity, rates of surgery, and mortality rates for different frailty groups during the pandemic and compared them to pre-pandemic levels. RESULTS: Of the 20,005 included hospitalizations for brain tumors, 7979 were during the pandemic (mean age 60.0 years (± 18.4); females: 49.8%), and 12,026 in the pre-pandemic period (mean age: 59.0 years [± 18.4]; females: 49.2%). Average daily admissions decreased from 8.2 (± 5.1) during pre-pandemic years to 7.3 (± 4.5) during the pandemic (p < 0.01). The overall median HFRS decreased from 3.1 (IQR: 0.9-7.3) during the pre-pandemic years to 2.6 (IQR: 0.3-6.8) during the pandemic (p < 0.01). At the same time, the Elixhauser Comorbidity Index (ECI) decreased from 17.0 (± 12.4) to 16.1 (± 12.0; p < 0.01), but to a larger degree among high compared to low frailty cases (by 1.8 vs. 0.3 points; p = 0.04). In the entire cohort, the mean length of stay was significantly shorter in the pandemic period (9.5 days [± 10.7]) compared with pre-pandemic levels (10.2 days [± 11.8]; p < 0.01) with similar differences in the three frailty groups. Rates of brain tumor resection increased from 29.9% in pre-pandemic years to 36.6% during the pandemic (p < 0.001) without differences between frailty levels. Rates of in-hospital mortality did not change during the pandemic (6.1% vs. 6.7%, p = 0.07), and there was no interaction with frailty. CONCLUSION: Even though our findings are limited in that the HFRS is validated only for patients ≥ 75 years of age, our study among patients of all ages hospitalized for brain tumors in Germany suggests a marked decrease in levels of frailty and in the burden of comorbidities during the COVID-19 pandemic.

Rationale and design of the peripheral nerve tumor registry: an observational cohort study.

AIM: Peripheral nerve tumors (PNT) are rare lesions. To date, no systematic multicenter studies on epidemiology, clinical symptoms, treatment strategies and outcomes, genetic and histopathologic features, as well as imaging characteristics of PNT were published. The main goal of our PNT Registry is the systematic multicenter investigation to improve our understanding of PNT and to assist future interventional studies in establishing hypotheses, determining potential endpoints, and assessing treatment efficacy. METHODS: Aims of the PNT registry were set at the 2015 Meeting of the Section of Peripheral Nerve Surgery of the German Society of Neurosurgery. A study protocol was developed by specialists in PNT care. A minimal data set on clinical status, treatment types and outcomes is reported by each participating center at initial contact with the patient and after 1 year, 2 years, and 5 years. Since the study is coordinated by the Charité Berlin, the PNR Registry was approved by the Charité ethics committee (EA4/058/17) and registered with the German Trials Registry (www.drks.de). On a national level, patient inclusion began in June 2016. The registry was rolled out across Europe at the 2019 meeting of the European Association of Neurosurgery in Dublin. RESULTS: Patient recruitment has been initiated at 10 centers throughout Europe and 14 additional centers are currently applying for local ethics approval. CONCLUSION: To date, the PNT registry has grown into an international study group with regular scientific and clinical exchange awaiting the first results of the retrospective study arm.

Peripheral nerve vulnerability as risk factor for multiple sclerosis: Possible insights from Neurofibromatosis type 2 (NF2).

Despite enormous research efforts, the disease mechanisms causing multiple sclerosis (MS) are still incompletely understood, suggesting a complex and multifaceted pathogenesis. Here, we report the clinical observation that in a designated German center for Neurofibromatosis type 2 (NF2), the number of MS cases among NF2 patients is higher than in the general population. Epidemiological studies investigating a connection between NF2 and MS are difficult to perform due to the rarity of NF2 disease. However, based on the current pathophysiological concepts, we hypothesize that genetically determined vulnerability of peripheral nerves and repeated nerve repair processes might constitute an unrecognized factor to the pathogenesis of MS and might explain the apparent over-representation of MS cases among NF2 patients.

Neurogenic Thoracic Outlet Syndrome.

BACKGROUND: Thoracic outlet syndrome (TOS) refers to a group of disorders in which there is compression of and/or damage to the neurovascular structures at the thoracic outlet, i.e., at the transition from chest to neck. The incidence of neurogenic thoracic outlet syndrome (nTOS) is estimated to be 2-3 / 100 000 / year, with an estimated prevalence of 10 / 100 000. Patients present with upper extremity sensorimotor symptoms that are often related to movement. The aim of the present article is to highlight the clinical presentation patterns of nTOS and to provide an overview of its diagnosis and treatment. METHODS: Selective literature search for prospective observational studies and RCTs, including systematic reviews and metaanalyses. RESULTS: There is no multicenter randomized controlled trial available on the treatment of nTOS. Prospective observational studies with a hierarchical study design report a positive effect of physiotherapy in 27-59% of cases. After unsuccessful conservative treatment, up to 56-90% benefit from surgical management. Patients with nTOS are more severely affected compared with those with other forms of TOS and benefit less from transaxillary first rib resection. nTOS patients who underwent supraclavicular decompression without rib resection had excellent surgical outcomes in 27%, good outcomes in 36%, acceptable outcomes in 26%, and poor surgical outcomes in 11% of cases. There is no systematic comparison available of the types of surgical management involved. Also, there is currently no uniform classification available for all medical sub-disciplines. Therefore, interpretation, and comparability of the study results are limited. CONCLUSION: Although nTOS is the most common form of TOS, studies on its treatment are currently limited in terms of numbers and quality. The type of surgical management varies according to the experience and preference of the surgeon, treating specialty, special anatomic features, and clinical symptoms.

The Neurofibromatoses.

BACKGROUND: Neurofibromatosis of types 1 and 2 (NF1, NF2) and schwannomatosis are the diseases that make up the neurofibromatosis spectrum. With respective incidences of 1 in 3000, 1 in 33 000, and 1 in 60 000 births, they form part of the group of rare tumor-suppressor syndromes. They give rise to a greater tumor burden for the nervous system than any other type of neoplastic disease. New approaches to symptomatic treatment are emerging. METHODS: This review is based on articles retrieved by a selective literature search on the pathogenesis, diagnosis, and treatment of the neurofibromatoses. RESULTS: NF1 and NF2 are monogenic diseases, while the genetics of schwannomatosis is complex. The three entities are clinically and pathophysiologically distinct. An important aspect of their tumor biology is the alternation of growth phases and growth pauses. Correlations between genotypes and phenotypes are variable, while new mutations and genetic mosaics are common. Ninety-nine percent of patients with NF1 have six or more café-au-lait spots by the age of 12 months; 90-95% of patients with NF2 develop bilateral vestibular schwannomas. In schwannomatosis, pain is the most prominent symptom; two-thirds of those affected develop spinal schwannomas. The severity and prognosis of these disorders are not closely correlated with the radiological findings; rather, neurologic deficits, malignant transformation, and psychosocial stress are of greater clinical importance. Advances in knowledge of pathophysiology have led to the development of targeted treatment approaches. Examples include the off-label treatment of vestibular schwannomas with bevacizumab and of plexiform neurofibromas with MEK inhibitors. CONCLUSION: Patients with neurofibromatoses need individualized care. They should be treated in centers of expertise where interdisciplinary consultation is available and new types of pharmacotherapy can be provided.

Neurofibromatosis type 2 and multiple sclerosis.

Comorbidity of neurofibromatosis type 2 (NF2) and multiple sclerosis (MS) has rarely been reported. Since immunological mechanisms have been implicated in Nf2, coexistence of the two entities may offer insights into schwannoma pathogenesis with respect to the impact of the immune system. We present the case of a woman with a de novo mutation in the NF2 gene who later developed MS. In addition, we found a significantly higher count of T cells in a laryngeal schwannoma of this patient as compared to a schwannoma removed from a NF2 patient without MS. This finding correlated with a higher growth rate in the case of NF+MS.

WHO grade of intracranial meningiomas differs with respect to patient's age, location, tumor size and peritumoral edema.

PURPOSE: To analyse whether the WHO grade of intracranial meningiomas differs itself depending on patients and meningioma characteristics at diagnosis. METHODS: Single center retrospective study of a series of consecutive patients with primary intracranial meningiomas who underwent surgery between January 2007 and March 2014. Patients (age, sex, outcome) and meningioma characteristics (histological diagnosis, tumor location, WHO grading, size, extend of peritumoral edema and tumor recurrence rate) were analysed. RESULTS: Of 240 included patients, 184 (76.7%) were female and 56 (23.3%) were male. 17 patients (7.1%) were in age group 20-40 years, 112 (46.7%) in group 41-60 years and 111 (46.3%) were in age group > 60 years. 189 patients (78.8%) were diagnosed with WHO grade I, 49 (20.4%) WHO grade II and 2 (0.8%) had a WHO grade III meningioma. WHO grade II meningiomas were significantly more frequent in the age group 20-40 years compared to age group 41-60 years (chi-square p < 0.05). Convexity meningiomas were significantly more frequent classified as WHO grade II meningiomas compared to all other locations (chi-square, p < 0.01). Mean calculated tumor volume and the tumor volume determined by volumetric measurement was significantly larger in grade II meningioma patients compared to grade I (46.3 ± 40.5 cc grade II versus 21.8 ± 27.8 cc grade I and 45.3 ± 38.2 cc versus 23.1 ± 30.0 cc respectively; t test < 0.01). Extend of the peritumoral edema was significantly larger in patients with grade II meningiomas (Wilcoxon test, p < 0.05). Short term outcome did not differ between different age groups nor was it associated with tumor size. During a mean follow up of 49 months (min 3, max 144 months) recurrence rate was significantly higher in WHO grade II (4 out of 49 [8.2]%) compared to WHO grade I patients (3 out if 186, [1.6%]; Chi-square, p < 0.05). CONCLUSION: In this series atypical meningioma was associated with younger age, location on the convexity, larger tumor size and more peritumoral edema.

Secondary sacral tethered cord syndrome after treatment of secondary cervical syringomyelia.

A female patient operated at the age of 11 on a pilocytic astrocytoma in the posterior fossa, was re-operated for a recurrence 9 years later. A Torkildsen drain was placed in the 4th ventricle and she remained asymptomatic for 15 years before presenting again with acute hydrocephalus, tonsillar herniation, and a massive cervicothoracic syrinx. The symptoms retreated following craniocervical untethering and decompression. Two weeks later, however, she suffered from debilitating radiculopathy provoked by tethering of the cauda equina. Again, symptoms retreated completely after microsurgical intervention. This combination of a secondary Chiari-like malformation with cervical syringomyelia and tethering of the cauda equina in a single patient as a delayed complication of posterior fossa surgery has not been reported before. Diagnosis and treatment of lower tethered cord syndrome may be obscured and delayed in complex clinical situations. In particular, awareness to symptoms that are not related to syringomyelia is important in patients with a known syrinx and a history of posterior fossa surgery.

Meta-Analysis on Safety and Efficacy of Microsurgical and Radiosurgical Treatment of Trigeminal Neuralgia.

BACKGROUND: Classic trigeminal neuralgia is often treated pharmacologically first. However, microvascular decompression (MVD) or radiosurgical treatment (RS) can render medication unnecessary. Objective appraisals of the 2 treatment modalities are scarce. OBJECTIVE: To compare the evidence regarding safety and efficiency of MVD and RS. METHODS: We searched PubMed for studies describing pain control, complications, and recurrences after MVD or RS between 2005 and 2015. Because randomized studies are lacking, we focused the statistical analysis on cohort clinical trials. Differences in outcome after treatment with either MVD or RS were analyzed using t tests and weighted averages. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. RESULTS: Fifty-three studies (13,805 patients, in 11 prospective and 42 retrospective studies) were analyzed. Initial success rates were 71.1% for RS and 86.9% for MVD (P < 0.0001). At last follow-up (>5 years after intervention), success rates decreased to 63.8% for RS versus 84% for MVD (P = 0.036). Thirty-six months after the intervention, median percentage of recurrence was 11% for MVD and 25% for RS (P = 0.0015). The length of recurrence-free intervals was similar for MVD and RS (30.45 vs. 30.55 months; P = 0.987). There was no significant difference between the incidence of hearing loss after MVD and RS (1.51% vs. 0.74%; P = 0.21). Facial dysesthesia was reported more frequently after radiosurgery (2.3% vs. 28.8%; P = 0.02). CONCLUSIONS: MVD is a valid first-line treatment option for young patients free of comorbidities. First-line RS can be advised in patients with a higher surgical risk.

Growth Dynamics of Intracranial Tumors in Patients with Neurofibromatosis Type 2.

OBJECTIVE: Patients with neurofibromatosis type 2 (NF2) are prone to develop multiple intracranial neoplasms, such as schwannomas of the cranial nerves and meningiomas. The aim of our study was to investigate 1) the median growth rate per year, 2) the growth-free interval, and 3) the growth patterns of NF2-associated intracranial tumors. METHODS: All available magnetic resonance (MR) images of patients from the regional neurofibromatosis center were collected. The depicted tumors' volumes were then calculated if the tumors met the following inclusion criteria: contrast enhanced T1-weighted MRI datasets had to be available from at least two investigations and tumors had to be measurable on at least two slices. RESULTS: One-hundred and eighty-eight tumors from 52 patients (20 male, 32 female) met the inclusion criteria for volumetric analysis. Overall, the median follow-up time was 76.5 months per patient (range 13-199 months). After 5 years, the median tumor size was 196% ± 338% for vestibular schwannomas (VS), 204% ± 702% meningiomas (M), 128% ± 64.9% for non-vestibular schwannomas (NVS) and 139% ± 270% for pre-operated tumors of the cerebellopontine angle (TX), respectively. The median time to 20% tumor progression was 21 months for VS, NVS and TX, and 17 months for M. Overall, saltatory growth was the most common growth pattern (46.9%). CONCLUSIONS: Most NF2-associated tumors display a saltatory growth pattern. Meningiomas and untreated vestibular schwannomas grow rapidly and overall at similar rates. Tumors of the CPA that have been operated on and non-vestibular schwannomas show less relative growth per year.

Encasement of the Cauda Equina After Early Childhood Meningitis: Case Report and Review of the Literature.

BACKGROUND: Arachnopathy following meningitis has been described in the setting of chronic spinal arachnoiditis and more recently as shunt-related progressive myelopathy due to meningeal thickening. CASE DESCRIPTION: We describe an atypical case of a patient who presented with chronic arachnopathy 5 decades after an episode of meningitis. We also review the literature concerning arachnopathies occurring in the context of early childhood meningitis. Although our case bore clinical and radiologic similarities to chronic spinal arachnoiditis and shunt-related progressive myelopathy, time to symptom onset, intraoperative findings, pathophysiology, and surgical outcome set it apart from both conditions. CONCLUSIONS: It is challenging but worthwhile to recognize this separate entity because, in contrast to both shunt-related progressive myelopathy due to meningeal thickening and adhesive arachnoiditis, surgery involving microsurgical dissection of the thick arachnoid encasement of the cauda equina may be curative in medically refractory cases.

Growth dynamics of intramedullary spinal tumors in patients with neurofibromatosis type 2.

OBJECTIVES: Volumetric data on the natural growth of intramedullary tumors in patients with neurofibromatosis type 2 (NF2) are rare, but crucial for long-term disease monitoring. Our aim was to evaluate the growth rates and growth patterns of these tumors. PATIENTS AND METHODS: Patient records from the regional neurofibromatosis referral center were evaluated for inclusion in this analysis. Magnetic resonance images of the spine were collected and digitized as necessary. Tumor volumes were determined by volumetric extrapolation after segmentation in datasets (iPlan Net software, BrainLAB, Munich) if the tumors met the following inclusion criteria: sagittal T2-weighted MRI scans had to be available from at least two investigations and tumors had to be visible on at least two slices. All tumors that had undergone previous therapy, such as surgery, radiation or bevacizumab treatment were excluded from this study. RESULTS: Suitable MR images of the spine were available from 51 patients (20 males, 31 females) with NF2. The median follow-up time per patient was 54 months (range 0-190 months). 23 patients (15 females, 11 males) of the 51 patients with spinal imaging harbored intramedullary tumors. Across this cohort, there was an aggregate of 68 tumors at baseline. Over the course of follow-up, the patients developed 19 additional tumors, resulting in a total of 87 tumors. A final set of 42 tumors from 19 patients met the inclusion criteria and was included in the growth analysis. The median follow-up time per tumor was 44 months (range 9-122 months). 23 of the tumors were located in the cervical spine; 19 of them were located in the thoracic spine. The median tumor size±standard deviation (SD) after 5 years was 136±71.0% compared to baseline. The median time to ≥20% tumor growth was 24 months. Overall, 30 tumors (71.4%) grew, 8 (19.1%) remained stable and 4 (9.52%) decreased in size. The most common growth pattern was saltatory growth. CONCLUSION: Intramedullary spinal cord tumors are present in about half of patients with NF2. The majority of these tumors grow over time, albeit slowly. Given the confines of the spinal medulla and the limited scope for functional recovery after symptomatic tumor expansion, NF2 patients should be under continual surveillance in order to rapidly identify intramedullary spinal tumors that may require microsurgical resection.

Evaluating vestibular schwannoma size and volume on magnetic resonance imaging: An inter- and intra-rater agreement study.

OBJECTIVES: In the management of patients with vestibular schwannoma it is essential to reliably assess tumor size. In respect to volumetric and linear measurements of these tumors we evaluated a) the inter-rater reliability, b) the intra-rater variability, c) the concordance of volume measurements derived from axial versus those from coronal MRI datasets, and d) the correlation of one-dimensional and volumetric measurements. PATIENTS AND METHODS: We selected gadolinium-enhanced T1-weighted MRI datasets from 20 patients who had both axial and coronal datasets available with the same slice thickness in each of these orientations. Tumor volumes and diameters were independently determined by two investigators. RESULTS: The inter-rater reliability was determined based on the intra-class correlation coefficient, which was 0.998 for volumetric measurements and 0.950 for diameters. The relative smallest detectable difference between both raters was 21.2% for volumetric and 21.2% for linear measurements. Regarding the intra-rater variability we found a relative smallest detectable difference of 17.5% (rater 1) and 24.3% (rater 2) for volumetric measurements. The correlation between measurements on axial and those on coronal datasets was ρ=0.999. In order to find a function that reliably predicts tumor volume from diameter, we fitted a series of equations based on linear and polynomial regression, with the highest regression coefficient being r(2)=0.79. CONCLUSION: The longitudinal use of semi-automated volumetric measurements has the potential to accurately inform vestibular schwannoma disease management. We have quantified the reliability of this technique. A strict MRI protocol for follow-up investigations should be adhered to in order to minimize measuring errors.

Superiority of tympanic ball electrodes over mastoid needle electrodes for intraoperative monitoring of hearing function.

OBJECT: Recording the auditory brainstem response (ABR) is a common method for monitoring the integrity of auditory pathways during surgery in the cerebellopontine angle. Electrocochleography (ECochG) is an alternative means of intraoperative neuromonitoring. In the present study the authors compared the practicability and prognostic significance of these two methods by performing simultaneous recordings in the operating room. METHODS: Between 2006 and 2011, 125 patients (mean age 55 years) underwent surgery in the cerebellopontine angle. Seventy-one percent of the patients presented with a hearing deficit, and 37% had useful hearing but with slight functional impairment. Auditory brainstem response was recorded with a subdermal needle electrode at the mastoid. For ECochG recording, a noninvasive ball electrode was attached to the tympanic membrane. Amplitudes obtained from both ECochG and ABR audiometry were compared and correlated to pre- and postoperative hearing deficits. RESULTS: Simultaneous intraoperative monitoring via ABR and ECochG was possible in 114 cases (91%). Postoperatively, 42% of patients showed some degree of new hearing deficit, whereas 4% had improvement. The mean amplitudes in ECochG monitoring were significantly higher (0.18 ± 0.04 µV) than the ABR potentials (0.08 ± 0.006 µV; p < 0.05). All waves recorded at the mastoid needle electrode could be recognized in the potentials of the tympanic ball electrode. Hearing outcome correlated more reliably with the relative amplitude changes in Waves III and V in ECochG (III: p = 0.0008, V: p = 0.0015) than in ABR monitoring (III: p = 0.2075, V: p = 0.0398). CONCLUSIONS: Intraoperative monitoring of the auditory system by recording with noninvasive tympanic ball electrodes is more practicable than with subcutaneous needle electrodes at the tragus. Since there is also a reliable correlation between ECochG and clinical outcome, the method can replace common ABR recording during surgery in the cerebellopontine angle.

Effect of acute and chronic bilateral visual deafferentation on c-Fos immunoreactivity in the visual system of adult rats.

In our study we examined acute and chronic changes in c-Fos expression patterns in the visual system of the rat after complete visual deafferentation. In 20 male Lewis rats, the retro-bulbar part of the optic nerve was sectioned bilaterally. Ten animals underwent c-Fos immunohistochemistry after 3 days and 10 animals after 3 weeks examining time-dependent changes. The control group consisted of 10 animals, which did not undergo any surgical manipulation. c-Fos expression in the rat visual system experienced significant changes after acute and chronic bilateral complete visual deafferentation. Acute decrease in c-Fos level was observed in the ventral lateral geniculate nucleus, intergeniculate leaflet, superficial gray layer of the superior colliculus and layers IV and V of the primary visual cortex. After chronic deafferentation, c-Fos expression was also found to be decreased in the optic and deep layers of the superior colliculus and layer VI of the primary visual cortex. No change in c-Fos expression was observed in the dorsal lateral geniculate nucleus and layers I, II and III of the primary visual cortex. This work shows that secondary complete blindness does not lead to uniform decrease in c-Fos levels in all subcortical and cortical brain regions related to vision. These findings provide important information concerning expression of the immediate-early gene product c-Fos in secondary blind rodent models. It may further serve as a relevant baseline finding when electrical stimulation of the visual system is performed, aiding the assessment of visual neuroprosthesis using c-Fos as a functional mapping tool when evaluating different stimulus parameters in blind rodent models.

No easy target: anatomic constraints of electrodes interfacing the human cochlear nucleus.

BACKGROUND: Auditory brainstem implants have failed to produce consistent clinical results comparable to those with the cochlear implant, both with surface and penetrating electrodes. OBJECTIVE: To determine neuromorphological constraints of the auditory brainstem implant interface. METHODS: The size, shape, surface depth, and spatial orientation of 33 human cochlear nuclei in 20 brainstem specimens obtained at autopsy were systematically analyzed in 792 slices each with a thickness of 8 µm. Three-dimensional renderings of the cochlear nucleus complex were obtained from a true-to-scale model, and the resulting photographic views were arranged according to the axes of the brainstem. RESULTS: The dimensions of the ventral and dorsal cochlear nuclei in the axial, coronal, and sagittal planes correlated linearly with each other. There were no significant side differences. Maximum dimensions of the whole cochlear nuclear complex were 8.01 × 1.53 × 3.76 mm. The appearance of the ventral and dorsal nuclei combined resembles a distorted X shape from a lateral view and an angulated wedge shape when viewed from above. Slanted into the depth of the brainstem above the facial nerve entrance, the superior boundary of the ventral nucleus is located more than 7 mm off the surface of the brainstem on average. CONCLUSION: In the absence of appropriate surface landmarks and imaging guidance, to gain tonotopic access to the human cochlear nucleus with surface and depth electrode remains a major challenge. Due to its location close to the surface, the dorsal cochlear nucleus is vulnerable to surgical manipulation and to tumors.

The impact of tinnitus and vertigo on patient-perceived quality of life after cerebellopontine angle surgery.

BACKGROUND: Quality of life (QOL) has come into focus after treatment for cerebellopontine angle (CPA) lesions. OBJECTIVE: This study compared subjective (tinnitus, vertigo) and objective (hearing loss, facial palsy) results of CPA surgery with patient-perceived impairment of QOL. METHODS: A retrospective analysis of a consecutive series of 48 patients operated on for either a vestibular schwannoma or a meningioma in the CPA was performed. Patient's subjective impairment of QOL by tinnitus, vertigo, hearing loss, and facial nerve palsy was assessed by a visual analog scale (VAS). Objective facial nerve and hearing function were determined using House-Brackmann and Gardner-Robertson classification systems, respectively. RESULTS: The return rate of questionnaires was 64.4%, with mean follow-up time of 417.2 (+/- 46.4) days. Mean preoperative tinnitus score was 2.5 (+/- 0.5) and increased to 4.6 (+/- 0.7) postoperatively (P < .01). The vertigo score increased from 2.0 (+/- 0.3) to 5.8 (+/- 0.6) (P < .001). Pre- and postoperative values for hearing loss were 3.4 (+/- 0.6) and 5.9 (+/- 0.7), respectively (P < .01), and for facial nerve palsy 0.7 (+/- 0.4) compared with 3.1 (+/- 0.6) postoperatively (P < .01). House-Brackmann grade 1 or 2 was determined in 87.1% of patients before and in 80.6% after surgery. Serviceable hearing (Gardner-Robertson classes I-III) was found in 75% before and in 64.3% after surgery. CONCLUSION: Preservation of facial nerve and hearing function are not the only important criteria defining QOL after CPA surgery. Tinnitus and vertigo may have a significant underestimated impact on the patient's postoperative course and QOL.