Search Results

You are looking at 1 - 10 of 32 items for

  • Author or Editor: Matthew L. Carlson x
  • Refine by Access: all x
Clear All Modify Search
Restricted access

Microvascular decompression for tinnitus: systematic review

Brenton Nash, Matthew L. Carlson, and Jamie J. Van Gompel

OBJECTIVE

The objective of this study was to examine operative outcomes in cases of microvascular decompression (MVD) of cranial nerve (CN) VIII for tinnitus through a critical review of the literature.

METHODS

Forty-three English-language articles were gathered from PubMed and analyzed. In this review, two different case types were distinguished: 1) tinnitus-only symptomatology, which was defined as a patient with tinnitus with or without sensorineural hearing loss; and 2) mixed symptomatology, which was defined as tinnitus with symptoms of other CN dysfunction. This review reports outcomes of those with tinnitus-only symptoms.

RESULTS

Forty-three tinnitus-only cases were found in the literature with a 60% positive outcome rate following MVD. Analysis revealed a 5-year cutoff of preoperative symptom duration before which a good outcome can be predicted with 78.6% sensitivity, and after which a poor outcome can be predicted with 80% specificity.

CONCLUSIONS

As the 60% success rate is more promising than several other therapeutic options open to the chronic tinnitus sufferer, future research into this field is warranted.

Free access

Editorial. Who, or what, to believe

Michael J. Link and Matthew L. Carlson

Restricted access

Pediatric cerebellopontine angle and internal auditory canal tumors

Clinical article

Michelle A. Holman, William R. Schmitt, Matthew L. Carlson, Colin L. W. Driscoll, Charles W. Beatty, and Michael J. Link

Object

The aim in this study was to describe the clinical presentation, differential diagnosis, and risk for neurofibromatosis Type 2 (NF2) in pediatric patients presenting with cerebellopontine angle (CPA) and internal auditory canal (IAC) tumors.

Methods

The authors conducted a retrospective study at a tertiary care academic referral center. All patients with an age ≤ 18 years who had presented with an extraaxial CPA or IAC tumor between 1987 and 2012 were included in the study cohort. Data regarding symptoms, diagnosis, tumor characteristics, and NF2 status were collected and analyzed.

Results

Sixty patients (55% female, 45% male) harboring 87 tumors were identified. The mean age at diagnosis was 12.8 years (median 14.0 years, range 0.9–18.9 years). Schwannomas were the most commonly identified lesions (57 of 87 tumors, including 52 vestibular, 3 facial, and 2 trigeminal schwannomas), followed by meningiomas (5 of 87) and epidermoid cysts (4 of 87). Six malignant tumors were diagnosed, including small-cell sarcoma, squamous cell carcinoma, malignant meningioma, atypical rhabdoid-teratoid tumor, endolymphatic sac tumor, and malignant ganglioglioma. Headache, followed by hearing loss and imbalance, was the most common presenting symptom, whereas dysphagia, otalgia, and facial pain were uncommon.

Neurofibromatosis Type 2 was diagnosed in 20 (61%) of 33 patients with vestibular schwannoma (VS), while the other 13 patients (39%) had sporadic tumors. Nineteen of the 20 patients with NF2 met the diagnostic criteria for that disorder on initial presentation, and 15 of them presented with bilateral VS. At the last follow-up, 19 of the 20 patients subsequently diagnosed with NF2 demonstrated bilateral VSs, whereas 1 patient with a unilateral VS and multiple other NF2-associated tumors has yet to demonstrate a contralateral VS to date. Only 1 patient presenting with an isolated unilateral VS and no family history of NF2 demonstrated a contralateral VS on subsequent radiological screening.

Conclusions

Cerebellopontine angle and IAC tumors in the pediatric population are rare. There are several noteworthy differences between the adult and pediatric populations harboring these lesions. While VS is the most common pathology in both age groups, the lesion was found in only 60% of the pediatric patients in the present study. Unlike in adults, VSs in the pediatric population were associated with NF2 in over one-half of all cases. The majority of pediatric patients with NF2 fulfilled the diagnostic criteria at initial presentation; however, approximately 7% of patients presenting with a seemingly sporadic (no family history of NF2) unilateral VS will meet the criteria for NF2 later in life. Finally, malignancies account for a significantly higher percentage (10%) of cases among pediatric patients. These findings underscore the importance of early screening and close radiological follow-up and may be helpful in patient counseling.

Restricted access

Vestibular schwannoma surgery in the elderly: a matched cohort study

Clinical article

Kathryn M. Van Abel, Matthew L. Carlson, Colin L. Driscoll, Brian A. Neff, and Michael J. Link

Object

The authors' objective was 2-fold: 1) to compare outcomes of microsurgical resection for vestibular schwannoma (VS) between patients aged 70 years or older and patients younger than 70 years and 2) to test the hypothesis that symptomatic tumors in elderly patients represent a more aggressive variant of VS than those in younger adults, resulting in increased morbidity and a higher rate of recurrence after subtotal resection (STR).

Methods

A retrospective matched cohort study was conducted. Patients aged 70 years or older who had undergone microsurgical resection of VS were matched to adult patients younger than 70 years; the matching was performed on the basis of surgical approach, completeness of resection, and tumor size. Associations between clinical, radiographic, and surgical data and postoperative outcome were analyzed using conditional logistic regression.

Results

Twenty patients aged 70 years or older (mean age ± SD 75.9 ± 5.3, range 70–86 years) were identified and matched to a cohort of younger adult patients (mean age ± SD 55.7 ± 13.8, range 25–69 years). The mean tumor size in both groups was approximately 3 cm. Overall, the elderly patients had a poorer preoperative American Society of Anesthesiology physical status score (p = 0.038), were more likely to report imbalance (OR 9.61, p = 0.016), and more commonly exhibited compromised balance and coordination (OR 9.61, p = 0.016) than patients in the younger cohort.

There were no differences between the 2 cohorts in perioperative complications (p = 0.26) or facial nerve function (p > 0.5) at any time. The elderly patients were 13 times more likely to have long-term postoperative imbalance (OR 13.00, p = 0.013) than the younger patients. Overall, 9 tumors recurred among 32 patients undergoing STR; 6 of these patients underwent additional interventions (stereotactic radiosurgery in 5 patients and microsurgery in 1) and showed no evidence of tumor progression at the last follow-up. The median growth rate of the recurrent tumor in the 6 elderly patients was 4.8 mm/year (range 2.1–14.9 mm/year) and, in the 3 control patients, 2.2 mm/year (range 1.9–4.0 mm/year). Overall, the mortality data showed a trend toward statistical significance (p = 0.068) with a higher risk of death in the elderly.

Conclusions

As the number of elderly patients with VS increases, microsurgical resection will remain an important management option for these patients. Despite a poorer preoperative physical status in elderly patients, their morbidity profiles are similar to those in adult patients younger than 70 years. However, elderly patients may require longer convalescence due to prolonged postoperative imbalance. Not surprisingly, overall diminished functional reserve and advanced comorbidities may increase the mortality risk associated with surgical intervention in the elderly patients. Finally, there was a high risk of further tumor growth following STR in the elderly patients (6 [37.5%] of 16), underscoring the need for close postoperative radiological surveillance and consideration of early stereotactic radiosurgery for the tumor remnant following the STR.

Full access

Letter to the Editor. How safe, really, is jugular paraganglioma radiosurgery?

Jonathan P. S. Knisely, Rohan Ramakrishna, and Theodore H. Schwartz

Restricted access

Malignant peripheral nerve sheath tumors of the eighth cranial nerve arising without prior irradiation

Matthew L. Carlson, Jeffrey T. Jacob, Elizabeth B. Habermann, Amy E. Glasgow, Aditya Raghunathan, and Michael J. Link

OBJECTIVE

Malignant peripheral nerve sheath tumors (MPNSTs) of the eighth cranial nerve (CN) are exceedingly rare. To date the literature has focused on MPNSTs occurring after radiation therapy for presumed benign vestibular schwannomas (VSs), while MPNSTs arising without prior irradiation have received little attention. The objectives of the current study are to characterize the epidemiology, clinical presentation, disease course, and outcome using a large national cancer registry database and a systematic review of the English literature. Additionally, a previously unreported case is presented.

METHODS

The authors conducted an analysis of the Surveillance, Epidemiology, and End Results (SEER) database, a systematic review of the literature, and present a case report. Data from all patients identified in the SEER database with a diagnosis of MPNST involving the eighth CN, without a history of prior radiation, were analyzed. Additionally, all cases reported in the English literature between January 1980 and March 2015 were reviewed. Finally, 1 previously unreported case is presented.

RESULTS

The SEER registries identified 30 cases between 1992 and 2012. The average incidence was 0.017 per 1 million persons per year (range 0.000–0.0687 per year). The median age at diagnosis was 55 years, and 16 (53%) were women. Thirteen cases were diagnosed upon autopsy. Of the 17 cases diagnosed while alive, the median follow-up was 118 days, with 3 deaths (18%) observed. When compared with the incidence of benign VS, 1041 VSs present for every 1 MPNST arising from the eighth CN. Including a previously unreported case from the authors' center, a systematic review of the English literature yielded 24 reports. The median age at diagnosis was 44 years, 50% were women, and the median tumor size at diagnosis was 3 cm. Eleven patients (46%) reported isolated audiovestibular complaints typical for VS while 13 (54%) exhibited facial paresis or other signs of a more aggressive process. Treatment included microsurgery alone, microsurgery with adjuvant radiation, or microsurgery with chemoradiation. Sixty-one percent of patients receiving treatment experienced recurrence, 22% of which were diagnosed with drop metastases to the spine. Ultimately, 13 patients (54%) died of progressive disease at a median of 3 months following diagnosis. The ability to achieve gross-total resection was the only feature that was associated with improved disease-specific survival.

CONCLUSIONS

MPNSTs of the eighth CN are extremely rare and portend a poor prognosis. Nearly half of patients initially present with findings consistent with a benign VS, often making an early diagnosis challenging. In light of these data, early radiological and clinical follow-up should be considered in those who elect nonoperative treatment, particularly in patients with a short duration of symptoms or atypical presentation. These data also provide a baseline rate of malignancy that should be considered when estimating the risk of malignant transformation following stereotactic radiosurgery for VS.

Restricted access

Radiation-induced rhabdomyosarcoma of the brainstem in a patient with neurofibromatosis Type 2

Case report

Matthew L. Carlson, Dusica Babovic-Vuksanovic, Ludwine Messiaen, Bernd W. Scheithauer, Brian A. Neff, and Michael J. Link

Neurofibromatosis Type 2 (NF2) is a rare autosomal dominant disorder characterized by the development of benign tumors of the peripheral nervous system and the CNS, including schwannomas, meningiomas, and ependymomas. The gene responsible for the development of NF2 acts as a tumor suppressor gene. Stereotactic radiotherapy (SRT) or single-fraction stereotactic radiosurgery has been increasingly used in the past decades to treat benign tumors in patients with NF2. These radiotherapy methods are less invasive and can be potentially used to treat multiple tumors in a single session. The risk of inducing malignancy is unclear. Few reports exist of malignant peripheral nerve sheath tumors, meningiomas, or ependymomas occurring after SRT or stereotactic radiosurgery in patients with NF2. The authors present the first documented case of rhabdomyosarcoma following SRT for multiple NF2-associated schwannomas. Compared with patients with sporadic tumors, NF2 patients having a germline tumor suppressor gene defect may be more prone to secondary malignancies after treatment involving radiation therapy.

Free access

Retrosigmoid craniotomy for resection of acoustic neuroma with hearing preservation: a video publication

Jonathan A. Forbes, Matthew L. Carlson, Saniya S. Godil, Marc L. Bennett, George B. Wanna, and Kyle D. Weaver

In this publication, video format is utilized to review the operative technique of retrosigmoid craniotomy for resection of acoustic neuroma with attempted hearing preservation. Steps of the operative procedure are reviewed and salient principles and technical nuances useful in minimizing complications and maximizing efficacy are discussed.

The video can be found here: http://youtu.be/PBE5rQ7B0Ls.

Restricted access

Use of supramaximal stimulation to predict facial nerve outcomes following vestibular schwannoma microsurgery: results from a decade of experience

Clinical article

William R. Schmitt, Jasper R. Daube, Matthew L. Carlson, Jayawant N. Mandrekar, Charles W. Beatty, Brian A. Neff, Colin L. Driscoll, and Michael J. Link

Object

The goal of vestibular schwannoma surgery is tumor removal and preservation of neural function. Intraoperative facial nerve (FN) monitoring has emerged as the standard of care, but its role in predicting long-term facial function remains a matter of debate. The present report seeks to describe and critically assess the value of applying current at supramaximal levels in an effort to identify patients destined for permanent facial paralysis.

Methods

Over more than a decade, the protocol for stimulating and assessing the FN during vestibular schwannoma surgery at the authors' institution has consisted of applying pulsed constant-current stimulation at supramaximal levels proximally and distally following tumor resection to generate an amplitude ratio, which subtracted from 100% yields the degree to which the functional integrity of the FN “dropped off” intraoperatively. These data were prospectively collected and additional variables that might impact postoperative FN function were retrospectively reviewed from the medical record. Only patients with anatomically intact FNs and > 12 months of follow-up data were analyzed.

Results

There were 267 patients available for review. The average posterior fossa tumor diameter was 24 mm and the rate of long-term good (House-Brackmann Grade I–II) FN function was 84%. Univariate logistic regression analysis revealed that prior treatment, neurofibromatosis Type 2 status, tumor size, cerebellopontine angle extension, subjectively thinned FN at the time of operation, minimal stimulation threshold, percent dropoff by supramaximal stimulation (SMS), and postoperative FN function all correlated statistically (p < 0.05) with long-term FN function. When evaluating patients with significant FN weakness at the time of hospital discharge, only the percent dropoff by SMS remained a significant predictor of long-term FN function. However, the positive predictive value of SMS for long-term weakness is low, at 46%.

Conclusions

In a large cohort of patients, the authors found that interrogating intraoperative FN function with SMS is safe and technically simple. It is useful for predicting which patients will ultimately have good facial function, but is very limited in identifying patients destined for long-term facial weakness. This test may prove helpful in the future in tailoring less than gross-total tumor removal to limit postoperative facial weakness.

Free access

Cochlear implantation after radiosurgery for vestibular schwannoma

Neil S. Patel, Matthew L. Carlson, Michael J. Link, Brian A. Neff, Jamie J. Van Gompel, and Colin L. W. Driscoll

OBJECTIVE

The object of this study was to ascertain outcomes of cochlear implantation (CI) following stereotactic radiosurgery (SRS) for vestibular schwannoma (VS).

METHODS

The authors conducted a retrospective chart review of adult patients with VS treated with SRS who underwent CI between 1990 and 2019 at a single tertiary care referral center. Patient demographics, tumor features, treatment parameters, and pre- and postimplantation audiometric and clinical outcomes are presented.

RESULTS

Seventeen patients (18 ears) underwent SRS and ipsilateral CI during the study period. Thirteen patients (76%) had neurofibromatosis type 2 (NF2). Median age at SRS and CI were 44 and 48 years, respectively. Median time from SRS to CI was 60 days, but notably, 4 patients underwent SRS and CI within 1 day and 5 patients underwent CI more than 7 years after SRS. Median marginal dose was 13 Gy. Median treatment volume at the time of SRS was 1400 mm3 (range 84–6080 mm3, n = 15 patients). Median post-CI PTA was 28 dB HL, improved from 101 dB HL preoperatively (p < 0.001). Overall, 11 patients (12 ears) exhibited open-set speech understanding. Sentence testing was performed at a median of 10 months (range 1–143 months) post-CI. The median AzBio sentence score for patients with open-set speech understanding was 76% (range 19%–95%, n = 10 ears). Two ears exhibited Hearing in Noise Test (HINT) sentence scores of 49% and 95%, respectively. Four patients achieved environmental sound awareness without open-set speech recognition. Two had no detectable auditory percepts.

CONCLUSIONS

Most patients who underwent CI following SRS for VS enjoyed access to sound at near-normal levels, with the majority achieving good open-set speech understanding. Implantation can be performed immediately following SRS or in a delayed fashion, depending on hearing status as well as other factors. This strategy may be applied to cases of sporadic or NF2-associated VS.