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Ron Ron Cheng, Ramin Eskandari, Cynthia T. Welsh, and Abhay K. Varma

Peripheral nerve involvement may be the first sign of systemic amyloid light-chain (AL) amyloidosis, a rare disease. Physical examination and electrodiagnostic testing are the mainstays of peripheral neuropathy evaluation at presentation. Sural nerve biopsy is performed in conjunction with serum and urine protein evaluation to differentiate between focal and systemic disease. Systemic disease is treated with a combination of chemotherapy, steroids, and stem cell transplantation. Isolated peripheral nerve disease is extremely rare.

The authors here report the case of an 80-year-old woman who presented with progressive right upper-extremity weakness due to right radial neuropathy discovered upon electrodiagnostic testing. Magnetic resonance neurography (MRN) revealed a focal lesion within the right radial nerve. She underwent radial nerve exploration and excision of an intraneural mass consisting of amyloid on histopathology, with mass spectrometry analysis diagnostic for AL amyloidosis. Noninvasive testing and clinical history did not suggest systemic involvement. This unique case of isolated peripheral nerve AL amyloidosis in the absence of signs and symptoms of systemic disease is described, and the literature demonstrating peripheral nerve involvement in AL amyloidosis is reviewed.

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Jacob A. Kahn, Jeffrey T. Waltz, Ramin M. Eskandari, Cynthia T. Welsh, and Michael U. Antonucci

The authors report an unusual presentation of juvenile xanthogranuloma (JXG), a non–Langerhans cell histiocytosis of infancy and early childhood. This entity typically presents as a cutaneous head or neck nodule but can manifest with more systemic involvement including in the central nervous system. However, currently there is limited information regarding specific imaging features differentiating JXG from other neuropathological entities, with diagnosis typically made only after tissue sampling. The authors reviewed the initial images of a young patient with shunt-treated hydrocephalus and enlarging, chronic, extraaxial processes presumed to reflect subdural collections from overshunting, and they examine the operative discovery of a mass lesion that was pathologically proven to be JXG. Their results incorporate the important associated histological and advanced imaging features, including previously unreported metabolic activity on FDG PET. Ultimately, the case underscores the need to consider JXG in differential diagnoses of pediatric intracranial masses and highlights the potential role of PET in the initial diagnosis and response to treatment.

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Thomas Larrew, Mohammed Alshareef, Robert F. Murphy, Ramin Eskandari, and Libby Kosnik Infinger

OBJECTIVE

Although the advent of magnetic growing rod technology for scoliosis has provided a means to bypass multiple hardware lengthening operations, it is important to be aware that many of these same patients have a codiagnosis of hydrocephalus with magnet-sensitive programmable ventricular shunts. As the magnetic distraction of scoliosis rods has not previously been described to affect the shunt valve setting, the authors conducted an investigation to characterize the interaction between the two devices.

METHODS

In this ex vivo study, the authors carried out 360 encounters between four different shunt valve types at varying distances from the magnetic external remote control (ERC) used to distract the growing rods. Valve settings were examined before and after every interaction with the remote control to determine if there was a change in the setting.

RESULTS

The Medtronic Strata and Codman Hakim valves were found to have setting changes at distances of 3 and 6 inches but not at 12 inches. The Aesculap proGAV and Codman Certas valves, typically described as MRI-resistant, did not have any setting changes due to the magnetic ERC regardless of distance.

CONCLUSIONS

Although it is not necessary to check a shunt valve after every magnetic distraction of scoliosis growing rods, if there is concern that the magnetic ERC may have been within 12 inches (30 cm) of a programmable ventricular shunt valve, the valve should be checked at the bedside with a programmer or with a skull radiograph along with postdistraction scoliosis radiographs.

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Ramin Eskandari, Michael R. Filtz, Gary E. Davis, and Robert E. Hoesch

Object

Normal intracranial pressure (ICP) and cerebral perfusion pressure (CPP) have been identified as favorable prognostic factors in the outcome of patients with traumatic brain injuries (TBIs). Osmotic diuretics and hypertonic saline (HTS) are commonly used to treat elevated ICP in patients with TBI; however, sustained effects of repeated high-concentration HTS boluses for severely refractory ICP elevation have not been studied. The authors' goal in this study was to determine whether repeated 14.6% HTS boluses were efficacious in treating severely refractory intracranial hypertension in patients with TBI.

Methods

In a prospective cohort study in a neurocritical care unit, adult TBI patients with sustained ICP > 30 mm Hg for more than 30 minutes after exhaustive medical and/or surgical therapy received repeated 15-minute boluses of 14.6% HTS over 12 hours through central venous access.

Results

Response to treatment was evaluated in 11 patients. Within 5 minutes of bolus administration, mean ICP decreased from 40 to 33 mm Hg (30% reduction, p < 0.05). Intracranial pressure–lowering effects were sustained for 12 hours (41% reduction, p < 0.05) with multiple boluses (mean number of boluses 7 ± 5.5). The mean CPP increased 22% and 32% from baseline at 15 and 30 minutes, respectively (p < 0.05). The mean serum sodium level (SNa) at baseline was 155 ± 7.1 mEq/L, and after multiple boluses of 14.6% HTS, SNa at 12 hours was 154 ± 7.1 mEq/L. The mean heart rate, systolic blood pressure, blood urea nitrogen, and creatinine demonstrated no significant change throughout the study.

Conclusions

The subset of TBI patients with intracranial hypertension that is completely refractory to all other medical therapies can be treated effectively and safely with repeated boluses of 14.6% HTS rather than a one-time dose.

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Guilherme B. F. Porto, Cynthia T. Welsh, M. Imran Chaudry, and Ramin Eskandari

Cystic angiomatosis is a rare bone condition with complex presentation and difficult treatment. Current management strategies have poorly tolerated side effects and a low likelihood of disease eradication. The control of calvarial lesions that are symptomatic usually involves surgical excision and subsequent cranioplasty. This paradigm can present with a risk of morbidity and mortality depending on the anatomy of the lesion. Here, the authors present a novel approach to a difficult-to-treat occipital calvarial lesion directly overlying the transverse sinus, performing a small, partial-thickness craniectomy and alcohol sclerotherapy in a combined neurosurgery-neuroendovascular approach. At 3 years after treatment, the authors noted a complete, encouraging radiographic and clinical outcome.

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Chelsea Shope, Mohammed Alshareef, Thomas Larrew, Christopher Bolling, Justin Reagan, Milad Yazdani, Maria Spampinato, and Ramin Eskandari

OBJECTIVE

Traumatic brain injury (TBI) is a prevalent pediatric pathology in the modern emergency department. Computed tomography (CT) is utilized for detection of TBI and can result in cumulatively high radiation exposure. Recently, a fast brain magnetic resonance imaging (fbMRI) protocol has been employed for rapid imaging of hydrocephalus in pediatric patients. The authors investigate the utility of a modified trauma-focused fbMRI (t-fbMRI) protocol as an alternative to surveillance CT in the setting of acute TBI in pediatric patients, thus reducing radiation exposure while improving diagnostic yield.

METHODS

A retrospective review was performed at the authors’ institution for all pediatric patients who had undergone t-fbMRI within 72 hours of an initial CT scan, using a 1.5- or 3-T MR scanner for trauma indications. Forty patients met the study inclusion criteria. The authors performed a comparison of findings on the reads of CT and fbMRI, and a board-certified neuroradiologist conducted an independent review of both modalities.

RESULTS

T-fbMRI outperformed CT in specificity, sensitivity, and negative predictive value for all injury pathologies measured, except for skull fractures. T-fbMRI demonstrated a sensitivity of 100% in the detection of extraaxial bleed, intraventricular hemorrhage, and subarachnoid hemorrhage and had a sensitivity of 78% or greater for epidural hematoma, subdural hematoma, and intraparenchymal hemorrhage. T-fbMRI yielded a specificity of 100% for all types of intracranial hemorrhages, with a corresponding negative predictive value that exceeded that for CT.

CONCLUSIONS

In pediatric populations, the t-fbMRI protocol provides a valid alternative to CT in the surveillance of TBI and intracranial hemorrhage. Although not as sensitive in the detection of isolated skull fractures, t-fbMRI can be used to monitor pathologies implicated in TBI patients while minimizing radiation exposure from traditional surveillance imaging.

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Ramin Eskandari, James P. McAllister II, Janet M. Miller, Yuchuan Ding, Steven D. Ham, David M. Shearer, and John S. Way

Object. The authors of previous studies have suggested that connectivity within the cerebral cortex may be irreversibly altered by hydrocephalus. To examine connectivity-related changes directly, the authors conducted a study in which they used an axonal tracer in an animal model of infantile hydrocephalus.

Methods. In five hydrocephalic kittens low-pressure ventriculoperitoneal (VP) shunts were placed 10 to 14 days after induction of hydrocephalus by intracisternal kaolin injections. Wheat germ agglutinin-conjugated horseradish peroxidase was injected laterally into the motor cortex in hydrocephalic animals 9 to 15 days after kaolin injection, and 1, 2, and 4 weeks after VP shunt insertion in shunt-treated animals, and in age-matched controls.

Reduction of antero- and retrograde labeling was most profound within the contralateral cortex and portions of the midbrain. Thalamic nuclei exhibited reductions in anterograde and retrograde labeling. Labeling within cell bodies of the ventral tegmental area decreased greatly in animals with untreated hydrocephalus, in which retrograde labeling was reduced in the locus coeruleus but did not affect the raphe nucleus. Shunt treatment increased both antero- and retrograde labeling of contralateral motor cortex to near-normal levels. Thalamic relay nuclei recovered antero- and retrograde labeling, although not to levels exhibited in controls. Shunt therapy restored cellular labeling within the ventral tegmental area and locus coeruleus. Recovery of labeling occurred as early as 7 days after shunt insertion.

Conclusions. Collectively, analysis of these data indicates the following. 1) Cortical connectivity involving both afferent and efferent pathways was impaired in untreated hydrocephalic animals. 2) Shunt therapy improved both cortical afferent and efferent connectivity. 3) Complete reestablishment of the cortical efferent pathways, however, did not occur. Cortical pathway dysfunction, if permanent, could cause many of the motor and cognitive deficits seen clinically in children with hydrocephalus.

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Alexander T. Yahanda, P. David Adelson, S. Hassan A. Akbari, Gregory W. Albert, Philipp R. Aldana, Tord D. Alden, Richard C. E. Anderson, David F. Bauer, Tammy Bethel-Anderson, Douglas L. Brockmeyer, Joshua J. Chern, Daniel E. Couture, David J. Daniels, Brian J. Dlouhy, Susan R. Durham, Richard G. Ellenbogen, Ramin Eskandari, Timothy M. George, Gerald A. Grant, Patrick C. Graupman, Stephanie Greene, Jeffrey P. Greenfield, Naina L. Gross, Daniel J. Guillaume, Todd C. Hankinson, Gregory G. Heuer, Mark Iantosca, Bermans J. Iskandar, Eric M. Jackson, James M. Johnston, Robert F. Keating, Mark D. Krieger, Jeffrey R. Leonard, Cormac O. Maher, Francesco T. Mangano, J. Gordon McComb, Sean D. McEvoy, Thanda Meehan, Arnold H. Menezes, Brent R. O’Neill, Greg Olavarria, John Ragheb, Nathan R. Selden, Manish N. Shah, Chevis N. Shannon, Joshua S. Shimony, Matthew D. Smyth, Scellig S. D. Stone, Jennifer M. Strahle, James C. Torner, Gerald F. Tuite, Scott D. Wait, John C. Wellons III, William E. Whitehead, Tae Sung Park, and David D. Limbrick Jr.

OBJECTIVE

Posterior fossa decompression with duraplasty (PFDD) is commonly performed for Chiari I malformation (CM-I) with syringomyelia (SM). However, complication rates associated with various dural graft types are not well established. The objective of this study was to elucidate complication rates within 6 months of surgery among autograft and commonly used nonautologous grafts for pediatric patients who underwent PFDD for CM-I/SM.

METHODS

The Park-Reeves Syringomyelia Research Consortium database was queried for pediatric patients who had undergone PFDD for CM-I with SM. All patients had tonsillar ectopia ≥ 5 mm, syrinx diameter ≥ 3 mm, and ≥ 6 months of postoperative follow-up after PFDD. Complications (e.g., pseudomeningocele, CSF leak, meningitis, and hydrocephalus) and postoperative changes in syrinx size, headaches, and neck pain were compared for autograft versus nonautologous graft.

RESULTS

A total of 781 PFDD cases were analyzed (359 autograft, 422 nonautologous graft). Nonautologous grafts included bovine pericardium (n = 63), bovine collagen (n = 225), synthetic (n = 99), and human cadaveric allograft (n = 35). Autograft (103/359, 28.7%) had a similar overall complication rate compared to nonautologous graft (143/422, 33.9%) (p = 0.12). However, nonautologous graft was associated with significantly higher rates of pseudomeningocele (p = 0.04) and meningitis (p < 0.001). The higher rate of meningitis was influenced particularly by the higher rate of chemical meningitis (p = 0.002) versus infectious meningitis (p = 0.132). Among 4 types of nonautologous grafts, there were differences in complication rates (p = 0.02), including chemical meningitis (p = 0.01) and postoperative nausea/vomiting (p = 0.03). Allograft demonstrated the lowest complication rates overall (14.3%) and yielded significantly fewer complications compared to bovine collagen (p = 0.02) and synthetic (p = 0.003) grafts. Synthetic graft yielded higher complication rates than autograft (p = 0.01). Autograft and nonautologous graft resulted in equal improvements in syrinx size (p < 0.0001). No differences were found for postoperative changes in headaches or neck pain.

CONCLUSIONS

In the largest multicenter cohort to date, complication rates for dural autograft and nonautologous graft are similar after PFDD for CM-I/SM, although nonautologous graft results in higher rates of pseudomeningocele and meningitis. Rates of meningitis differ among nonautologous graft types. Autograft and nonautologous graft are equivalent for reducing syrinx size, headaches, and neck pain.

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Andrew T. Hale, P. David Adelson, Gregory W. Albert, Philipp R. Aldana, Tord D. Alden, Richard C. E. Anderson, David F. Bauer, Christopher M. Bonfield, Douglas L. Brockmeyer, Joshua J. Chern, Daniel E. Couture, David J. Daniels, Susan R. Durham, Richard G. Ellenbogen, Ramin Eskandari, Timothy M. George, Gerald A. Grant, Patrick C. Graupman, Stephanie Greene, Jeffrey P. Greenfield, Naina L. Gross, Daniel J. Guillaume, Gregory G. Heuer, Mark Iantosca, Bermans J. Iskandar, Eric M. Jackson, James M. Johnston, Robert F. Keating, Jeffrey R. Leonard, Cormac O. Maher, Francesco T. Mangano, J. Gordon McComb, Thanda Meehan, Arnold H. Menezes, Brent O’Neill, Greg Olavarria, Tae Sung Park, John Ragheb, Nathan R. Selden, Manish N. Shah, Matthew D. Smyth, Scellig S. D. Stone, Jennifer M. Strahle, Scott D. Wait, John C. Wellons, William E. Whitehead, Chevis N. Shannon, David D. Limbrick Jr., and for the Park-Reeves Syringomyelia Research Consortium Investigators

OBJECTIVE

Factors associated with syrinx size in pediatric patients undergoing posterior fossa decompression (PFD) or PFD with duraplasty (PFDD) for Chiari malformation type I (CM-I) with syringomyelia (SM; CM-I+SM) are not well established.

METHODS

Using the Park-Reeves Syringomyelia Research Consortium registry, the authors analyzed variables associated with syrinx radiological outcomes in patients (< 20 years old at the time of surgery) with CM-I+SM undergoing PFD or PFDD. Syrinx resolution was defined as an anteroposterior (AP) diameter of ≤ 2 mm or ≤ 3 mm or a reduction in AP diameter of ≥ 50%. Syrinx regression or progression was defined using 1) change in syrinx AP diameter (≥ 1 mm), or 2) change in syrinx length (craniocaudal, ≥ 1 vertebral level). Syrinx stability was defined as a < 1-mm change in syrinx AP diameter and no change in syrinx length.

RESULTS

The authors identified 380 patients with CM-I+SM who underwent PFD or PFDD. Cox proportional hazards modeling revealed younger age at surgery and PFDD as being independently associated with syrinx resolution, defined as a ≤ 2-mm or ≤ 3-mm AP diameter or ≥ 50% reduction in AP diameter. Radiological syrinx resolution was associated with improvement in headache (p < 0.005) and neck pain (p < 0.011) after PFD or PFDD. Next, PFDD (p = 0.005), scoliosis (p = 0.007), and syrinx location across multiple spinal segments (p = 0.001) were associated with syrinx diameter regression, whereas increased preoperative frontal-occipital horn ratio (FOHR; p = 0.007) and syrinx location spanning multiple spinal segments (p = 0.04) were associated with syrinx length regression. Scoliosis (HR 0.38 [95% CI 0.16–0.91], p = 0.03) and smaller syrinx diameter (5.82 ± 3.38 vs 7.86 ± 3.05 mm; HR 0.60 [95% CI 0.34–1.03], p = 0.002) were associated with syrinx diameter stability, whereas shorter preoperative syrinx length (5.75 ± 4.01 vs 9.65 ± 4.31 levels; HR 0.21 [95% CI 0.12–0.38], p = 0.0001) and smaller pB-C2 distance (6.86 ± 1.27 vs 7.18 ± 1.38 mm; HR 1.44 [95% CI 1.02–2.05], p = 0.04) were associated with syrinx length stability. Finally, younger age at surgery (8.19 ± 5.02 vs 10.29 ± 4.25 years; HR 1.89 [95% CI 1.31–3.04], p = 0.01) was associated with syrinx diameter progression, whereas increased postoperative syrinx diameter (6.73 ± 3.64 vs 3.97 ± 3.07 mm; HR 3.10 [95% CI 1.67–5.76], p = 0.003), was associated with syrinx length progression. PFD versus PFDD was not associated with syrinx progression or reoperation rate.

CONCLUSIONS

These data suggest that PFDD and age are independently associated with radiological syrinx improvement, although forthcoming results from the PFDD versus PFD randomized controlled trial (NCT02669836, clinicaltrials.gov) will best answer this question.

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Jennifer M. Strahle, Rukayat Taiwo, Christine Averill, James Torner, Chevis N. Shannon, Christopher M. Bonfield, Gerald F. Tuite, Tammy Bethel-Anderson, Jerrel Rutlin, Douglas L. Brockmeyer, John C. Wellons III, Jeffrey R. Leonard, Francesco T. Mangano, James M. Johnston, Manish N. Shah, Bermans J. Iskandar, Elizabeth C. Tyler-Kabara, David J. Daniels, Eric M. Jackson, Gerald A. Grant, Daniel E. Couture, P. David Adelson, Tord D. Alden, Philipp R. Aldana, Richard C. E. Anderson, Nathan R. Selden, Lissa C. Baird, Karin Bierbrauer, Joshua J. Chern, William E. Whitehead, Richard G. Ellenbogen, Herbert E. Fuchs, Daniel J. Guillaume, Todd C. Hankinson, Mark R. Iantosca, W. Jerry Oakes, Robert F. Keating, Nickalus R. Khan, Michael S. Muhlbauer, J. Gordon McComb, Arnold H. Menezes, John Ragheb, Jodi L. Smith, Cormac O. Maher, Stephanie Greene, Michael Kelly, Brent R. O’Neill, Mark D. Krieger, Mandeep Tamber, Susan R. Durham, Greg Olavarria, Scellig S. D. Stone, Bruce A. Kaufman, Gregory G. Heuer, David F. Bauer, Gregory Albert, Jeffrey P. Greenfield, Scott D. Wait, Mark D. Van Poppel, Ramin Eskandari, Timothy Mapstone, Joshua S. Shimony, Ralph G. Dacey Jr., Matthew D. Smyth, Tae Sung Park, and David D. Limbrick Jr.

OBJECTIVE

Scoliosis is frequently a presenting sign of Chiari malformation type I (CM-I) with syrinx. The authors’ goal was to define scoliosis in this population and describe how radiological characteristics of CM-I and syrinx relate to the presence and severity of scoliosis.

METHODS

A large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°).

RESULTS

Based on available imaging of patients with CM-I and syrinx, 260 of 825 patients (31%) had a clear diagnosis of scoliosis based on radiographs or coronal MRI. Forty-nine patients (5.9%) did not have scoliosis, and in 516 (63%) patients, a clear determination of the presence or absence of scoliosis could not be made. Comparison of patients with and those without a definite scoliosis diagnosis indicated that scoliosis was associated with wider syrinxes (8.7 vs 6.3 mm, OR 1.25, p < 0.001), longer syrinxes (10.3 vs 6.2 levels, OR 1.18, p < 0.001), syrinxes with their rostral extent located in the cervical spine (94% vs 80%, OR 3.91, p = 0.001), and holocord syrinxes (50% vs 16%, OR 5.61, p < 0.001). Multivariable regression analysis revealed syrinx length and the presence of holocord syrinx to be independent predictors of scoliosis in this patient cohort. Scoliosis was not associated with sex, age at CM-I diagnosis, tonsil position, pB–C2 distance (measured perpendicular distance from the ventral dura to a line drawn from the basion to the posterior-inferior aspect of C2), clivoaxial angle, or frontal-occipital horn ratio. Average curve magnitude was 29.9°, and 37.7% of patients had a left thoracic curve. Older age at CM-I or syrinx diagnosis (p < 0.0001) was associated with greater curve magnitude whereas there was no association between syrinx dimensions and curve magnitude.

CONCLUSIONS

Syrinx characteristics, but not tonsil position, were related to the presence of scoliosis in patients with CM-I, and there was an independent association of syrinx length and holocord syrinx with scoliosis. Further study is needed to evaluate the nature of the relationship between syrinx and scoliosis in patients with CM-I.