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J. Alex Thomas, William O. Bank and John S. Myseros

Glossopharyngeal (that is, cranial nerve IX) schwannomas are extremely rare nerve sheath tumors that frequently mimic the more common vestibular schwannoma in their clinical as well as radiographic presentation. Although rare in adults, this tumor has not been reported in a child. The authors report the case of a 10-year-old boy who presented with several months of unilateral hearing loss. He was found to have a large right cerebellopontine angle tumor. Given the boy's primary complaint of hearing loss and the appearance of the lesion on imaging, the tumor was initially believed to be a schwannoma of the vestibular nerve. It was found intraoperatively, however, to originate from the glossopharyngeal nerve. To the authors' knowledge, this is the first reported case of a glossopharyngeal schwannoma in a child.

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Joshua J. Wind, Randy S. Bell, William O. Bank and John S. Myseros

The authors present the case of a 3-month-old boy with a third ventricular tumor consistent with a choroid plexus papilloma. This child presented with macrocephaly, irritability, inability to roll over, and vomiting. He was found to have an enlarged head circumference, a full and tense fontanel, splayed sutures, and forced downward gaze. Imaging revealed severe ventriculomegaly and a brightly enhancing third ventricular lesion consistent with papilloma. Treatment planning included placement of a ventriculoperitoneal shunt to treat hydrocephalus and to allow the child to grow prior to resection. Due to the vascular nature of these tumors and the age of this child, the tumor was embolized with a plan for eventual resection; however, embolization resulted in involution and total regression of the tumor. There is no residual disease at last follow-up of 16 months. In this specific scenario of a choroid plexus papilloma in an infant, when operative intervention may be technically difficult and associated with significant morbidity, embolization with close observation may be a valid treatment option. If used, the patient would need to be closely followed for evidence of residual or recurrent disease, which would require operative intervention.

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Eric R. Trumble, J. Paul Muizelaar, John S. Myseros, Sung C. Choi and Brian B. Warren

✓ The use of colloid agents to achieve hypervolemia in the prevention and treatment of postsubarachnoid hemorrhage (post-SAH) vasospasm is included in the standard of care at many institutions. Risk profiles are necessary to ensure appropriate use of these agents. In a series of 85 patients with recent aneurysmal SAH, 26 developed clinical symptoms of vasospasm. Fourteen of the 26 were treated with hetastarch for volume expansion while the other 12 received plasma protein fraction (PPF). Clinically significant bleeding pathologies were noted in six patients who received hetastarch as a continuous intravenous infusion. Hetastarch increased partial thromboplastin time from a mean of 23.9 seconds to a mean of 33.1 seconds (p < 0.001) in all patients who received infusions of this agent, while no effect was noted in the 12 patients who received PPF infusions. No other coagulation parameters were altered. This study shows an increase in coagulopathy with the use of hetastarch as compared with the use of PPF for the treatment of postaneurysmal vasospasm.

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Alan Siu, Michaela Lee, Robert Rice and John S. Myseros

Atypical teratoid/rhabdoid tumors (AT/RTs) are highly malignant CNS tumors found almost exclusively in childhood. Although essentially universally fatal when incompletely resected, prompt diagnosis followed by early chemoradiation can improve outcomes. An AT/RT can occur extraaxially at the cerebellopontine angle (CPA) and cause acute cranial nerve deficits as the presenting sign. The authors report a series of 3 children who presented with isolated acute facial nerve palsies and in whom subsequent diagnosis of a CPA AT/RT was made. The authors propose that in young children whose presenting symptom is an acute facial nerve palsy with a CPA tumor, AT/RT should be highly suspected.

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John S. Myseros, William C. Broaddus, Eric R. Trumble and Robert S. Adelaar

✓ A case of postfusion lumbar stenosis caused by the presence of sublaminar hooks is described. The patient was a 52-year-old man who 11 years previously had undergone lumbar fusion with Harrington rod instrumentation for a traumatic L-2 vertebral body fracture. Postoperatively, he developed progressive low-back pain, neurogenic claudication, and significant lower-extremity weakness and atrophy. Upon radiological examination, he was found to have high-grade lumbar stenosis at the level of the caudal sublaminar hooks. The instrumentation was removed and the area of radiological stenosis decompressed. Clinically, both the patient's pain and motor deficits resolved and, on postoperative imaging, the stenosis was relieved. Thus, despite other areas of persisting pathology, it is concluded that the stenosis occurring at the level of the caudal sublaminar hooks contributed to the patient's symptoms. Although not a common cause of postfusion stenosis, the presence of instrumentation in the proximity of neural elements must be considered as an etiology for neurological dysfunction.

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Ross Bullock, Alois Zauner, John J. Woodward, John Myseros, Sung C. Choi, John D. Ward, Anthony Marmarou and Harold F. Young

Recent animal studies demonstrate that excitatory amino acids (EAAs) play a major role in neuronal damage after brain trauma and ischemia. However, the role of EAAs in patients who have suffered severe head injury is not understood. Excess quantities of glutamate in the extracellular space may lead to uncontrolled shifts of sodium, potassium, and calcium, disrupting ionic homeostasis, which may lead to severe cell swelling and cell death. The authors evaluated the role of EEAs in human traumatic brain injury.

In 80 consecutive severely head injured patients, a microdialysis probe was placed into the gray matter along with a ventriculostomy catheter or an intracranial pressure (ICP) monitor for 4 days. Levels of EAAs and structural amino acids were analyzed using high-performance liquid chromatography. Multifactorial analysis of the amino acid pattern was performed and its correlations with clinical parameters and outcome were tested. The levels of EAAs were increased up to 50 times normal in 30% of the patients and were significantly correlated to levels of structural amino acids both in each patient and across the whole group (p < 0.01). Secondary ischemic brain injury and focal contusions were most strongly associated with high EAA levels (27 ± 22 μmol/L). Sustained high ICP and poor outcome were significantly correlated to high levels of EAAs (glutamate > 20 μmol/L; p < 0.01).

The release of EAAs is closely linked to the release of structural amino acids and may thus reflect nonspecific development of membrane micropores, rather than presynaptic neuronal vesicular exocytosis. The magnitude of EAA release in patients with focal contusions and ischemic events may be sufficient to exacerbate neuronal damage, and these patients may be the best candidates for treatment with glutamate antagonists in the future.

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Ross Bullock, Alois Zauner, John J. Woodward, John Myseros, Sung C. Choi, John D. Ward, Anthony Marmarou and Harold F. Young

Object. Recent animal studies demonstrate that excitatory amino acids (EAAs) play a major role in neuronal damage after brain trauma and ischemia. However, the role of EAAs in patients who have suffered severe head injury is not understood. Excess quantities of glutamate in the extracellular space may lead to uncontrolled shifts of sodium, potassium, and calcium, disrupting ionic homeostasis, which may lead to severe cell swelling and cell death. The authors evaluated the role of EEAs in human traumatic brain injury.

Methods. In 80 consecutive severely head injured patients, a microdialysis probe was placed into the gray matter along with a ventriculostomy catheter or an intracranial pressure (ICP) monitor for 4 days. Levels of EAAs and structural amino acids were analyzed using high-performance liquid chromatography. Multifactorial analysis of the amino acid pattern was performed and its correlations with clinical parameters and outcome were tested. The levels of EAAs were increased up to 50 times normal in 30% of the patients and were significantly correlated to levels of structural amino acids both in each patient and across the whole group (p < 0.01). Secondary ischemic brain injury and focal contusions were most strongly associated with high EAA levels (27 ± 22 µmol/L). Sustained high ICP and poor outcome were significantly correlated to high levels of EAAs (glutamate > 20 µmol/L; p < 0.01).

Conclusions. The release of EAAs is closely linked to the release of structural amino acids and may thus reflect nonspecific development of membrane micropores, rather than presynaptic neuronal vesicular exocytosis. The magnitude of EAA release in patients with focal contusions and ischemic events may be sufficient to exacerbate neuronal damage, and these patients may be the best candidates for treatment with glutamate antagonists in the future.

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Siri Sahib S. Khalsa, Alan Siu, Tiffani A. DeFreitas, Justin M. Cappuzzo, John S. Myseros, Suresh N. Magge, Chima O. Oluigbo and Robert F. Keating

OBJECTIVE

Previous studies have indicated an association of Chiari malformation Type I (CM-I) and a small posterior fossa. Most of these studies have been limited by 2D quantitative methods, and more recent studies utilizing 3D methodologies are time-intensive with manual segmentation. The authors sought to develop a more automated tool to calculate the 3D posterior fossa volume, and correlate its changes after decompression with surgical outcomes.

METHODS

A semiautomated segmentation program was developed, and used to compare the pre- and postoperative volumes of the posterior cranial fossa (PCF) and the CSF spaces (cisterna magna, prepontine cistern, and fourth ventricle) in a cohort of pediatric patients with CM-I. Volume changes were correlated with postoperative symptomatic improvements in headache, syrinx, tonsillar descent, cervicomedullary kinking, and overall surgical success.

RESULTS

Forty-two pediatric patients were included in this study. The mean percentage increase in PCF volume was significantly greater in patients who showed clinical improvement versus no improvement in headache (5.89% vs 1.54%, p < 0.05) and tonsillar descent (6.52% vs 2.57%, p < 0.05). Overall clinical success was associated with a larger postoperative PCF volume increase (p < 0.05). These clinical improvements were also significantly associated with a larger increase in the volume of the cisterna magna (p < 0.05). The increase in the caudal portion of the posterior fossa volume was also larger in patients who showed improvement in syrinx (6.63% vs 2.58%, p < 0.05) and cervicomedullary kinking (9.24% vs 3.79%, p < 0.05).

CONCLUSIONS

A greater increase in the postoperative PCF volume, and specifically an increase in the cisterna magna volume, was associated with a greater likelihood of clinical improvements in headache and tonsillar descent in patients with CM-I. Larger increases in the caudal portion of the posterior fossa volume were also associated with a greater likelihood of improvement in syrinx and cervicomedullary kinking.

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Benjamin C. Wood, Albert K. Oh, Robert F. Keating, Michael J. Boyajian, John S. Myseros, Suresh N. Magge and Gary F. Rogers

OBJECT

Progressive postnatal pansynostosis (PPP) is a rare form of craniosynostosis that is characterized by a normal head shape, insidious decrease in percentile head circumference, and high rates of elevated intracranial pressure (ICP). This investigation describes the clinical, radiographic, and genetic features of this entity.

METHODS

The authors’ craniofacial database for the period 1997–2013 was retrospectively culled to identify patients who had a normal or near-normal head shape and CT-confirmed multiple-suture synostosis. Patients with kleeblatt-schädel or previous craniofacial surgery were excluded. All demographic information was collected and analyzed.

RESULTS

Seventeen patients fit the inclusion criteria. Nine patients had a syndromic diagnosis: Crouzon syndrome (n = 4), Pfeiffer syndrome (n = 2), Saethre-Chotzen syndrome (n = 1), Apert syndrome (n = 1), and achondroplasia (n = 1). With the exception of 3 patients with mild turricephaly, all patients had a relatively normal head shape. Patients were diagnosed at an average age of 62.9 months. Nearly all patients had some combination of clinical, radiographic, or ophthalmological evidence of increased ICP.

CONCLUSIONS

PPP is insidious; diagnosis is typically delayed because the clinical signs are subtle and appear gradually. All normocephalic infants or children with a known or suspected craniosynostotic disorder should be carefully monitored; any decrease in percentile head circumference or signs/symptoms of increased ICP should prompt CT evaluation.

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Mitchel Seruya, Albert K. Oh, Michael J. Boyajian, John S. Myseros, Amanda L. Yaun and Robert F. Keating

Object

Intraoperative blood loss represents a significant concern during open repair of craniosynostosis, and its reliable measurement remains a serious challenge. In this study of extended sagittal synostectomies, the authors analyzed the relationship between estimated blood loss (EBL) and calculated blood loss (CBL), and investigated predictors of hemodynamic outcomes.

Methods

The authors reviewed outcomes in infants with sagittal synostosis who underwent primary extended synostectomies (the so-called Pi procedure) between 1997 and 2009. Patient demographic data, operating time, and mean arterial pressures (MAPs) were recorded. Serial MAPs were averaged for a MAPmean. The EBL was based on anesthesia records, and the CBL on pre- and postoperative hemoglobin values in concert with transfusion volumes. Factors associated with EBL, CBL, red blood cell transfusion (RBCT), and hospital length of stay (LOS) were investigated. Hemodynamic outcomes were reported as percent estimated blood volume (% EBV), and relationships were analyzed using simple and multiple linear and logistic regression models. A p value < 0.05 was considered significant.

Results

Seventy-one infants with sagittal synostosis underwent primary extended synostectomies at a mean age and weight of 4.9 months and 7.3 kg, respectively. The average operating time was 1.4 hours, and intraoperative MAP was 54.6 mm Hg (21.3% lower than preoperative baseline). There was no association between mean EBL (12.7% EBV) and mean CBL (23.6% EBV) (r = 0.059, p = 0.63). The EBL inversely correlated with the patient's age (r = −0.07) and weight (r = −0.11) at surgery (p < 0.05 in both instances). With regard to intraoperative factors, EBL positively trended with operating time (r = 0.26, p = 0.09) and CBL inversely trended with MAPmean (r = −0.04, p = 0.10), although these relationships were only borderline significant. Intraoperative RBCT, which was required in 59.1% of patients, positively correlated with EBL (r = 1.55, p < 0.001), yet negatively trended with CBL (r = −0.40, p = 0.01). Undertransfusion was significantly more common than overtransfusion (40.8% vs 22.5%, p = 0.02, respectively). The mean hospital LOS was 2.3 days and was not significantly associated with patient demographic characteristics, intraoperative factors, blood loss, RBCT, or total fluid requirements.

Conclusions

In extended synostectomies for sagittal synostosis, EBL and CBL demonstrated a decided lack of correlation with one another. Intraoperative blood transfusion positively correlated with EBL, but inversely correlated with CBL, with a significantly higher proportion of patients undertransfused than overtransfused. These findings highlight the need for reliable, real-time monitoring of intraoperative blood loss to provide improved guidance for blood and fluid resuscitation.