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ABSTRACT: The objective of this study is to investigate late repeat microvascular decompression (MVD) with persistent or recurrent hemifacial spasm (HFS) and to compare the clinical characteristics, intraoperative findings, complications, and outcomes with first MVD. We analyzed MVDs performed at the University of Pittsburgh Medical Center between January 1, 2000 and December 31, 2007. Thirty-three patients who underwent late redo MVDs were classified as group I and 243 patients who underwent their first MVD as group II. Clinical data were collected to analyze the difference between the two groups. The mean follow-up period was 54.48 months (range, 9-102 months). There is no significant difference in preoperative clinical characteristics (gender, age, side of MVD, botox usage, facial weakness) between the two groups. In present study, we found a vein as the offending vessel in significantly more number of patients who underwent repeat MVD as compared to first MVD (P = 0.02). The lateral spread response disappeared in 66 % of patients during repeat MVDs, which is not different from those undergoing their first MVD. No difference in the relief rate was found during the immediate postoperative, discharge, or follow-up stages between repeat and first MVD. Moreover, no difference was found in the incidence of complications between repeat MVD and first MVD. Late repeat MVD for HFS is an effective and safe procedure. No specific preoperative clinical characteristics were identified in patients with repeat MVD. Intraoperative monitoring with lateral spread response (LSR) is an effective tool to evaluate adequate decompression. In patients with persistent LSR at the end of the procedure, facial nerve compression from a vein should be examined. We believe that it is important to undergo a repeat MVD for failed HFS relief irrespective of the timing of the operation.
Neurosurgical Review 06/2013; · 2.04 Impact Factor
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ABSTRACT: The objective of this study is to investigate the clinical characteristics, intraoperative findings, complications, and outcomes in these patients with hemifacial spasm (HFS) caused by venous compression.
We analyzed 15 patients who underwent microvascular decompression (MVD) for HFS caused by venous compression performed at the University of Pittsburgh Medical Center between 1 January 2000 and 31 December 2007. Thirteen of 15 patients underwent repeat MVD, and two patients underwent their first MVD. Clinical data were collected to verify vein as real offending vessel for all of 15 patients with HFS. The mean follow-up period was 4·13 years (range: 1·29-6·76 years).
Thirteen patients with repeat MVDs had vein as the offending vessel, such as series of small venule, small veins, and dilated venous stump. The remaining two patients who underwent the first MVD had vein as the only offending vessel. In the first MVD for 13 patients, lateral spread response (LSR) disappeared in five patients (38·5%). In the repeat MVD for these 13 patients, LSR disappeared after the vein was decompressed completely in nine patients (69·2%). An excellent surgical outcome was observed in all the 11 patients with four patients lost during the follow-up period. Post-operative complications were observed in 12 patients included hearing loss, cerebrospinal fluid leakage, worsening facial palsy, difficulty swallowing, dilpopia, and ataxia.
Vein can play an important role and can be the offending vessel in MVD for HFS. Women with platysmal involvement and tonus seem to have higher chance of vein as an offending vessel. These patients that have residual LSR at the end of the procedure should undergo exploration for a vein to prevent persistent HFS. Intraoperative monitoring with LSR is an effective tool to evaluate adequate decompression to vein. Although the long-term outcome is excellent for venous compression, the complication rate is much higher. To decrease the complication rate, gentle retraction of the cerebellum and 'low-power' coagulation of the vein might be helpful.
Neurological Research 05/2013; 35(4):389-94. · 1.52 Impact Factor
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ABSTRACT: Object Microvascular decompression (MVD) of the facial nerve is an effective treatment for patients with hemifacial spasm. Intraoperative monitoring of brainstem auditory evoked potentials (BAEPs) during MVD can reduce the incidence of hearing loss. In this study the authors' goal was to evaluate changes in interpeak latencies (IPLs) of Waves I-V, Waves III-V, and Waves I-III of BAEP Waveforms I, III, and V during MVD and correlate them with postoperative hearing loss. To date, no such study has been performed. Hearing loss is defined as nonuseful hearing (Class C/D), which is a pure tone average of more than 50 dB and/or speech discrimination score of less than 50%. Methods The authors performed a retrospective analysis of IPLs of BAEPs in 93 patients who underwent intraoperative BAEP monitoring during MVD. Patients who did not have hearing loss were in Class A/B and those who had hearing loss were in Class C/D. Results Binary logistic regression analysis of independent IPL variables was performed. A maximum change in IPLs of Waves I-III and Waves I-V and on-skin change in IPLs of Waves I-V increases the odds of hearing loss. However, on adjusting the same variables for loss of response, change in IPLs did not increase the odds of hearing loss. Conclusions Changes in IPL measurements did not increase the odds of postoperative hearing loss. This information might be helpful in evaluating the value of IPLs as alarm criteria during MVD to prevent hearing loss.
Neurosurgical FOCUS 03/2013; 34(3):E6. · 2.87 Impact Factor
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ABSTRACT: Object The objective of this study was to investigate the clinical characteristics, intraoperative findings, complications, and outcomes after the first microvascular decompression (MVD) in patients with and without previous botulinum neurotoxin treatment for hemifacial spasm (HFS). Methods The authors analyzed 246 MVDs performed at the University of Pittsburgh Medical Center between January 1, 2000, and December 31, 2007. One hundred and seventy-six patients with HFS underwent botulinum neurotoxin injection treatment prior to first MVD (Group I), and 70 patients underwent their first MVD without previous botulinum neurotoxin treatment (Group II). Clinical outcome data were obtained immediately after the operation, at discharge, and at follow-up. Follow-up data were collected from 177 patients with a minimum follow-up period of 9 months (mean 54.48 ± 27.84 months). Results In 246 patients, 89.4% experienced immediate postoperative relief of spasm, 91.1% experienced relief at discharge, and 92.7% experienced relief at follow-up. There was no significant difference in outcomes and complications between Group I and Group II (p > 0.05). Preoperatively, patients in Group I had higher rates of facial weakness, tinnitus, tonus, and platysmal involvement as compared with Group II (p < 0.05). The posterior inferior cerebellar artery and vertebral artery were intraoperatively identified as the offending vessels in cases of vasculature compression in a significantly greater number of patients in Group II compared with Group I (p = 0.008 and p = 0.005, respectively, for each vessel). The lateral spread response (LSR) disappeared in 60.48% of the patients in Group I as compared with 74.19% in Group II (p > 0.05). No significant differences in complications were noted between the 2 groups. Conclusions Microvascular decompression is an effective and safe procedure for patients with HFS previously treated using botulinum neurotoxin. Intraoperative monitoring with LSR is an effective tool for evaluating adequate decompression.
Neurosurgical FOCUS 03/2013; 34(3):E3. · 2.87 Impact Factor
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ABSTRACT: OBJECTIVES: To evaluate the value of intraoperative neurophysiological monitoring (IONM) using brainstem auditory evoked potential (BAEP) and somatosensory evoked potential (SSEP) monitoring to predict and/or prevent postoperative neurological deficits during endoscopic endonasal surgery (EES). METHODS: We retrospectively identified 138 consecutive patients who had BAEP monitoring in addition to SSEP monitoring during EES at our institution. We reviewed the postoperative clinical outcomes and neurophysiological changes independently. RESULTS: The total of number of patients with any IONM changes was 10. The incidence of BAEP changes was 3.62%. The incidence of SSEP changes was 3.62% as well. One patient had changes in both BAEPs and SSEPs. Majority of the changes were observed during changes in mean arterial pressure (MAP) without any postoperative neurological deficits. There were two postoperative neurological deficits. DISCUSSION: BAEPs and SSEPs provide unique information about integrity of brainstem function during EES procedures involving tumors in the and around clival region. We advocate a comprehensive multimodality approach to IONM during EESs including BAEPs and SSEPs depending on the location of the neural structures at risk.
Neurological Research 02/2013; · 1.52 Impact Factor
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Tingting Ying,
Parthasarathy Thirumala,
Aalap Shah,
Tara Nikonow,
Kelley Wichman,
Maura Holmes,
Barry Hirsch,
Yuefang Chang,
Paul Gardner,
Miguel Habeych,
Donald J Crammond,
Lois Burkhart,
Michael Horowitz, Jeffrey Balzer
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ABSTRACT: Object The primary aim of this study was to evaluate the incidence and discuss the pathogenesis of high-frequency hearing loss (HFHL) after microvascular decompression (MVD) for hemifacial spasm (HFS). Methods Preoperative and postoperative audiogram data and brainstem auditory evoked potentials (BAEPs) from 94 patients who underwent MVD for HFS were analyzed. Pure tone audiometry at 0.25-2 kHz, 4 kHz, and 8 kHz was calculated for all individuals pre- and postoperatively ipsilateral and contralaterally. Intraoperative neurophysiological data were reviewed independently. An HFHL was defined as a change in pure tone audiometry of more than 10 dB at frequencies of 4 and 8 kHz. Results The incidence of HFHL was 50.00% and 25.53% ipsilateral and contralateral to the side of surgery, respectively. The incidence of HFHL adjusted for conductive and nonserviceable hearing loss was 26.6% ipsilaterally. The incidence of HFHL at 4 and 8 kHz on the ipsilateral side was 37.23% and 45.74%, respectively, and it was 10.64% and 25.53%, respectively, on the contralateral side. Maximal change in interpeak latency Waves I-V compared with baseline was the only variable significantly different between groups (p < 0.05). Sex, age, and side did not increase the risk of HFHL. Stepwise logistic regression analysis did not find any changes in intraoperative BAEPs to increase the risk of HFHL. Conclusions High-frequency hearing loss occurs in a significant number of patients following MVD surgery for HFS. Drill-induced noise and transient loss of CSF during surgery may impair hearing in the high-frequency ranges on both the ipsilateral and contralateral sides, with the ipsilateral side being more affected. Changes in intraoperative BAEPs during MVD for HFS were not useful in predicting HFHL. Follow-up studies and repeat audiological examinations may be helpful in evaluating the time course and prognosis of HFHL. Prospective studies focusing on decreasing intraoperative noise exposure, as well as auditory shielding devices, will establish causation and allow the team to intervene appropriately to decrease the risk of HFHL.
Journal of Neurosurgery 02/2013; · 2.96 Impact Factor
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Aalap Shah,
Tara Nikonow,
Parthasarathy Thirumala,
Barry Hirsch,
Yuefang Chang,
Paul Gardner, Jeffrey Balzer,
Miguel Habeych,
Donald Crammond,
Lois Burkhart,
Michael Horowitz
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ABSTRACT: Facial nerve microvascular decompression (MVD) for hemifacial spasm (HFS) provides relief to most patients. Due to the proximity of the cochlear and facial nerves, hearing loss is a potential MVD complication, however, there is a wide range in the reported incidence of hearing loss (HL) in the literature. In order to better understand the HL incidence in our MVD population, we utilized the combination of speech discrimination scores (SDS) and air and bone pure tone threshold averages (PTA) to identify patients with no hearing change, sensorineural hearing loss, or conductive hearing loss. We also assessed the predictive value of patient-reported hearing deficits on the ultimate audiometric diagnosis of hearing loss.
One hundred and fifty one patients underwent facial nerve MVD at the University of Pittsburgh Medical Center between January 2000 and December 2007. Peri-operative audiometric data, including changes in air and bone pure tone thresholds and speech discrimination scores, were analyzed retrospectively. Criteria from the 1995 American Academy of Otolaryngology Committee on Hearing and Equilibrium consensus were used to analyze post-operative hearing loss. Patient-reported hearing disturbances obtained in the immediate post-operative period were compared to seven-day post-operative conductive and sensorineural HL status.
Non-functional, non-serviceable HL (Class D) occurred in 6.6% of patients, while 10.6% developed cumulative non-functional HL (Class C and D). Twenty-nine patients (18.7%) exhibited conductive HL. While patient-reported complaints were predictive of Class C/D HL (<0.0001) with a 56.3% sensitivity and 92.6% specificity, patient-reported complaints were not strongly associated with conductive HL status (p = 0.369) with 17.2% sensitivity and 88.5% specificity.
Perioperative hearing evaluations, in conjunction with careful scrutiny of patient complaints and air-bone pure tone testing enables the physician to more precisely quote complication rates and rapidly distinguish potentially reversible conductive hearing pathologies from permanent sensorineural disorders.
Clinical neurology and neurosurgery 03/2012; 114(6):673-7. · 1.30 Impact Factor
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ABSTRACT: The use of ultrasonic technology for bone removal offers the potential advantages over the use of traditional hand instruments or cutting burrs of more precise bone resection and reduced soft-tissue injury. While the use of modified ultrasonic aspirators has been described for bone removal in spinal surgery, none of these instruments has been systematically examined to evaluate safety and efficacy. Thus, we compared laminectomies using traditional instruments, and traditional instruments with an ultrasonic osteotome, in an ovine model. We used a combination of clinical examination, intra-operative and post-operative neuromonitoring and histological analysis to evaluate safety. The secondary endpoint of efficiency was assessed by examining operative times. No significant difference was found between groups in neurophysiology or the Tarlov clinical rating scale. Histology revealed inflammatory or reparative changes in 6/8 experimental animals and 2/4 control animals with a single section in an experimental animal revealing focal nerve root disruption and mild axonal loss. A single durotomy was noted in both the control and experimental groups. Operative time for the experimental group was significantly shorter than the operative time for the control group.
Journal of Clinical Neuroscience 09/2011; 18(11):1528-33. · 1.25 Impact Factor
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ABSTRACT: Delayed cerebral ischemia (DCI) is a major complication after aneurysmal subarachnoid hemorrhage (aSAH); it is manifested by changes in cerebral blood flow accompanied by neurological decline, and it results in long-term functional and neuropsychological impairment. Preclinical evidence has demonstrated that the arachidonic acid metabolite, 20-hydroxyeicosatetraenoic acid (20-HETE), affects cerebral microvascular tone and cerebral blood flow after aSAH. The purpose of this study was to determine whether cerebrospinal fluid 20-HETE levels were associated with DCI and long-term neuropsychological outcomes in aSAH patients.
Cerebrospinal fluid samples were collected twice daily through 14 days after hemorrhage on 108 acute, adult, aSAH patients. Samples were analyzed for 20-HETE via HPLC MSQ single quadrupole mass spectrometry. DCI was defined as the presence of impaired cerebral blood flow (angiographic vasospasm, elevated transcranial Dopplers, abnormal computed tomography or magnetic resonance perfusion scans) accompanied by neurological deterioration. Outcomes, including death and neuropsychological testing, were completed at 3 months after hemorrhage.
Detectable 20-HETE levels were observed in 31% of patient samples and were associated with severity of hemorrhage (Hunt & Hess [HH], P=0.04; Fisher, P=0.05). Detection of 20-HETE was not associated with angiographic vasospasm (P=0.34); however, detectable 20-HETE was significantly associated with DCI (P=0.016). Our data also suggest that detectable 20-HETE was associated with decreased performance in 5 neuropsychological domains.
These results provide the first clinical evidence that cerebrospinal fluid 20-HETE concentrations are associated with DCI and poor outcomes, and this provides impetus for future studies to elucidate the clinical utility of inhibiting 20-HETE formation as a novel therapeutic intervention in patients with aSAH.
Stroke 05/2011; 42(7):1872-7. · 5.73 Impact Factor
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Parthasarathy D Thirumala,
Amin B Kassasm,
Miguel Habeych,
Kelley Wichman,
Yue-Fang Chang,
Paul Gardner,
Daniel Prevedello,
Carl Snyderman,
Ricardo Carrau,
Donald J Crammond, Jeffrey Balzer
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ABSTRACT: Intraoperative neurophysiological monitoring, including upper- and lower-extremity somatosensory evoked potentials (SSEPs), has been used to identify and prevent injury to neurovascular structures during conventional skull base surgery. The expanded endonasal approach (EEA) is a novel minimally invasive approach to skull base surgery. However, it carries the risk of injury to neurovascular structures, including the internal carotid artery, anterior cerebral artery, and cranial nerves.
To evaluate the value of SSEP monitoring to predict and/or prevent neurovascular deficits during EEA to skull base surgery.
We retrospectively identified 999 consecutive patients who had intraoperative neurophysiological monitoring during EEA skull base surgery at our institution. A total of 976 patients had SSEP monitoring and a documented postoperative neurological examination.
The incidence of changes in SSEP during the procedure was 20 of 976 (2%). The incidence of new postoperative neurological deficits was 5 of 976 (0.5%). The positive and negative predictive values of SSEPs during EEA to predict neurovascular deficits were 80.00% and 99.79%, respectively.
Intraoperative SSEP monitoring was able to identify impending risk to neurovascular structures to prevent permanent postoperative neurological deficits. We advocate a comprehensive approach to neurophysiological monitoring during EEAs, including SSEPs, spontaneous and triggered electromyography of the cranial nerves III through XII, brainstem auditory evoked potentials, and electroencephalogram, depending on the surgical approach and location of the neural structures at risk.
Neurosurgery 03/2011; 69(1 Suppl Operative):ons64-76; discussion ons76. · 2.79 Impact Factor
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ABSTRACT: Aneurysmal subarachnoid hemorrhage (SAH) is a hemorrhagic stroke subtype with a poor recovery profile. Cerebral vasospasm (CV), a narrowing of the cerebral vasculature, significantly contributes to the poor recovery profile. Variation in the endothelial nitric oxide (NO) synthase (eNOS) gene has been implicated in CV and outcome after SAH. The purpose of this project was to explore the potential association between three eNOS tagging single nucleotide polymorphisms (SNPs) and recovery from SAH. We included 195 participants with a diagnosis of SAH and DNA and 6-month outcome data available but without preexisting neurologic disease/deficit. Genotyping was performed using an ABI Prism 7000 Sequence Detection System and TaqMan assays. CV was verified by cerebral angiogram independently read by a neurosurgeon on 118 participants. Modified Rankin Scores (MRS) and Glasgow Outcome Scale (GOS) scores were collected 6 months posthemorrhage. Data were analyzed using descriptive statistics, analysis of variance (ANOVA) and chi-square analysis as appropriate. The sample was primarily female (n=147; 75.4%) and White (n=178; 91.3%) with a mean age of 54.6 years. Of the participants with CV data, 56 (47.5%) developed CV within 14 days of SAH. None of the SNPs individually were associated with CV presence; however, a combination of the three variant SNPs was significantly associated with CV (p=.017). Only one SNP (rs1799983, variant allele) was associated with worse 6-month GOS scores (p<.001) and MRS (p<.001). These data indicate that the eNOS gene plays a role in the response to SAH, which may be explained by an influence on CV.
Biological Research for Nursing 05/2009; 11(1):42-52. · 1.28 Impact Factor
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ABSTRACT: Intracellular calcium (Ca++) regulation of cerebral vessels is impaired after subarachnoid hemorrhage (SAH), making secondary pathways, such as that involving apolipoprotein E, potentially more influential. To evaluate cerebrospinal fluid (CSF) apolipoprotein E and Ca++ levels as biomarkers of cerebral vasospasm, we examined changes in levels over time and apolipoprotein E (APOE) epsilon4 allele presence after SAH in individuals with and without vasospasm. We hypothesized that individuals with low apolipoprotein E levels, increased Ca++ levels and/or at least one copy of the APOE epsilon4 allele would have vasospasm. Daily samples from 50 participants, aged 18-75, with SAH were used to quantify apolipoprotein E and Ca++ levels. Vasospasm was verified using cerebral angiogram and/or elevated transcranial Dopplers in combination with clinical neurologic deterioration. Overall apolipoprotein E levels were higher in individuals with the APOE epsilon4 allele (p = .02) or angiographic vasospasm (p = .01), but there were no differences between individuals with and without symptomatic vasospasm. There were no significant changes in apolipoprotein E levels over time. Individuals with the epsilon4 allele had lower Ca++ levels (p = .02) with trends suggesting a different pattern of change over time (p = .07). CSF Ca++ levels were lower in individuals with symptomatic vasospasm (p < .01). Change in apolipoprotein E and Ca++ levels (p = .006) correlated over time regardless of genotype or vasospasm status. These findings suggest that apolipoprotein E and Ca++ may be interacting after SAH, but this interaction does not appear to influence vasospasm.
Biological Research for Nursing 11/2008; 10(2):102-12. · 1.28 Impact Factor
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ABSTRACT: We describe a unique method of accessing the ventromedial skull base and lower craniocervical junction. Our method employs a trajectory between that of the more anterior transoral or retropharyngeal approaches and the various posterior or posterolateral skull base approaches. This "extended" lateral approach allows surgeons to resect very large tumors of the skull base through a single incision. The operative field is more extensive than that achieved with other approaches; it extends from the cerebellar hemisphere to the extradural ventral upper cervical spine, and it provides access to tissue outside the spinal canal, such as the ventral strap muscles. We describe our use of this approach during a single-stage resection of a large hemangiopericytoma in a 37-year-old man.
Ear, nose, & throat journal 06/2005; 84(5):312-5. · 0.66 Impact Factor
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Neurosurgery Clinics of North America 05/2005; 16(2):231-9, vii. · 1.76 Impact Factor
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ABSTRACT: Neurotransplantation has focused on disorders that involve subcortical brain targets. We evaluated the concepts of epileptic focus repair and changes in animal behavior through replacement of lost hippocampal neurons. The safety of hippocampal neurotransplantation was assessed in the rat kainic acid (KA) epilepsy model.
Sixty-three rats were studied and classified into six groups: KA plus 40,000 LBS-Neurons (Layton BioScience, Sunnyvale, CA; n = 13); KA plus 80,000 cells (n = 12); KA plus media (n = 9); no-KA plus 40,000 cells (n = 12); no-KA plus 80,000 cells (n = 12); and no-KA plus media (n = 5). Clinical observation (2 h daily) and electroencephalogram recording (3 h every other week) were performed to check for seizures until Week 11 after KA injection. On Week 12, the Morris water maze test was performed to assess spatial learning and memory.
Four rats were excluded because of intracranial hematoma or abscess. In the clinical observation of seizures, the no-KA plus media group had significantly fewer seizures than rats that received KA followed by injection of 40,000 cells, 80,000 cells, or media (P = 0.001, 0.0004, and 0.004, respectively). On electroencephalographic analysis, there was no significant difference between any of the groups. Transplanted rats with KA-induced epilepsy did not have an increased number of seizures. In the Morris water maze test, the hidden platform task showed that the KA plus 80,000 cell group had significantly longer swim latencies than groups with no-KA plus 40,000 cells (P = 0.035) or no-KA plus 80,000 cells (P = 0.015), demonstrating the behavioral deficits caused by KA injection. The probe trial showed no significant difference for the percentage of time in the target quadrant between any of the groups. Histological studies showed that 26 (59%) of 44 transplanted rats had evidence of graft survival.
The safety of cortical neurotransplantation was demonstrated, even in an animal model predisposed to epilepsy. We did not find evidence for cessation of seizures or improvement in behavior using this model.
Neurosurgery 08/2004; 55(1):191-8; discussion 198-200. · 2.79 Impact Factor
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ABSTRACT: For many years, neurosurgeons and otolaryngologic surgeons have used the fibrin glue product Tisseel to repair skull-base spinal fluid leaks and to help secure repairs following anterior cranial-base surgery. Despite the widespread use, the potential focal cerebral toxicity of this fibrin glue has never been investigated. We studied the safety of Tisseel applied directly to neural tissue (brain parenchyma, cervical cord, and C3-C6 spinal roots) of 6 monkeys (Macaca nemestrina) to determine if any underlying biochemical injury would occur. Another 3 animals that served as controls received saline rather than Tisseel. We found that median nerve electroencephalographic tracings and somatosensory evoked potentials in the experimental and control animals were identical. Likewise, cerebrospinal fluid indicators of neuronal or brain injury, inflammatory responses, and infection were negative in both groups. Finally, there were no significant differences between the two groups with respect to edema volumes and apparent diffusion coefficient values. We conclude that Tisseel does not induce an apparent inflammatory response or abnormal neurophysiologic or histologic response within 5 days of its application when it is applied directly to the brain parenchyma or onto the cervical spinal cord.
Ear, nose, & throat journal 05/2004; 83(4):246-8, 250, 252 passim. · 0.66 Impact Factor
