✓Ventriculoperitoneal (VP) shunt failure is a common problem encountered by pediatric neurosurgeons. The majority of such failures are due to obstruction of the device. Conditions in which intraabdominal pressure is chronically elevated, such as pregnancy, have been associated with shunt failure. Chronic constipation may also result in abnormally elevated intraabdominal pressure and may be an underrecognized cause of distal VP shunt failure. The authors describe the cases of two children who presented with clinical and imaging evidence of VP shunt failure and who were also severely constipated. Treatment of their constipation resulted in both clinical and imaging-documented resolution of their shunt failure.
Report of two cases
Ciaran J. Powers, Timothy George and Herbert E. Fuchs
Shahid M. Nimjee, Ciaran J. Powers, Roger E. McLendon, Gerald A. Grant and Herbert E. Fuchs
Cerebrospinal fluid overproduction resulting in communicating hydrocephalus is observed in patients who have choroid plexus papilloma or choroid plexus carcinoma. Less often, patients with these conditions have diffuse villous hyperplasia. Prior studies report CSF production greater than 3 L per day in these patients. These patients are treated with CSF shunting or by either unilateral choroid plexectomy or staged bilateral choroid plexectomy. The authors present a patient who had a number of congenital anomalies and a karyotype that revealed balanced translocations, 5 to 7 and 9 to 11. She presented with hydrocephalus and had CSF production of 5 L per day, greater output than ever previously reported. She was treated with a single-stage bilateral choroid plexectomy. Histopathological analysis revealed a bilateral choroid plexus papilloma. Postoperatively, the patient responded well clinically and showed radiographic improvement of her hydrocephalus. Bilateral choroid plexus papilloma has been reported in the literature as a cause for neonatal and congenital hydrocephalus. It can result in high CSF output and can be successfully treated with a single-stage bilateral choroid plexectomy. Further studies are ongoing to identify genes involved in embryogenesis of the choroid plexus.
Ben Waldau, Leahthan F. Domeshek, Fawn A. Leigh, Kristian C. Lum, Herbert E. Fuchs, Jeffrey R. Marcus, Srinivasan Mukundan and Gerald A. Grant
The case of a 3-year-old patient with tuberous sclerosis and a 13-mm Chiari malformation Type I that spontaneously disappeared over the course of 4 years is presented. Using morphometric measurements of the posterior fossa and cerebellum in this patient, the authors show that the volume of the posterior fossa at the time of initial evaluation was consistent with that reported as normal in the literature (180.24 cm3; normal volume 132–198 cm3). Moreover, the patient showed a normal rate of growth of his posterior fossa over the period of observation (201.05 cm3; normal range 153–230 cm3). Cerebellar volumes were found to increase only minimally during this time period, which is compatible with observations in healthy controls. The posterior fossa volume, on the other hand, was shown to increase significantly more than that of the cerebellum (p = 0.0185). This differential growth may permit the tonsils to ascend back up into the posterior fossa. Therefore, pediatric patients with normal posterior fossa volumes and normal development may have a spontaneous resolution of their asymptomatic Chiari malformation Type I.
Sharad Rajpal, R. Shane Tubbs, Timothy George, W. Jerry Oakes, Herbert E. Fuchs, Mark N. Hadley and Bermans J. Iskandar
Children with spina bifida occulta require early surgery to prevent neurological deficits. The treatment of patients with a congenitally tethered cord who present in adulthood remains controversial.
The authors studied the medical records of 61 adult patients who underwent surgical untethering for spina bifida occulta at three institutions between 1994 and 2003. Patients who had undergone prior myelomeningocele repair or tethered cord release surgery were excluded.
The most common intraoperative findings were lipomyelomeningocele (41%) and a tight terminal filum (36%). The follow-up duration ranged from 10.8 to 149.5 months. Of the 34 patients with back pain, status improved in 65%, worsened in 3%, remained unchanged in 18%, and improved and later recurred in 15%. Lower-extremity pain improved in 16 patients (53%), remained unchanged in 23%, improved and then recurred in 17%, and worsened in 7%. Lower-extremity weakness improved in 47%, remained unchanged in 47%, and improved and then recurred in 5%. Finally, of the 17 patients with lower-extremity sensory changes, status improved in 35%, remained unchanged in 35%, and the information on five patients was unavailable. Surgical complications included three wound infections, one cerebrospinal fluid leak, and two pseudomeningoceles requiring surgical revision. One patient developed acute respiratory distress syndrome and sepsis postoperatively and died several days later.
Adult-age presentation of a congenital tethered cord is unusual. Despite a slight increase in postoperative neurological injury in adults, surgery has relatively low risk and offers good potential for neurological improvement or stabilization. As they do in children, the authors recommend early surgery in adults with this disorder. The decision to undertake surgery, however, should be modulated by other factors such as a patient's general medical condition and risk posed by anesthesia.
Albert Moghrabi, Henry S. Friedman, David M. Ashley, Krystal S. Bottom, Tracy Kerby, Elizabeth Stewart, Carol Bruggers, James M. Provenzale, Martin Champagne, Linda Hershon, Melody Watral, Janis Ryan, Karima Rasheed, Shelley Lovell, David Korones, Herbert Fuchs, Timothy George, Roger E. McLendon, Allan H. Friedman, Edward Buckley and Darryl C. Longee
In this study, the authors sought to investigate the response rate and toxicity of carboplatin in patients with progressive low-grade glioma (LGG). Thirty-two patients with progressive LGG were treated with carboplatin at a dosage of 560 mg/m2. Treatment was given at 4-week intervals and continued until the disease progressed, unacceptable toxicity supervened, or for 12 additional courses after achieving maximal response. Patients with stable disease were treated with a total of 12 cycles. All patients were treated as outpatients. Patients were evaluated for response to treatment and toxicity.
All patients received a minimum of two cycles of carboplatin, and were examined for response. A partial response was achieved in nine patients (28%) and a minimal response in two (6%), for an overall response rate of 34% (11 of 32 patients). Eighteen patients (56%) had stable disease. A partial response was achieved in the nine patients after a median of six cycles (range 4-11 cycles), a minimal response was achieved in the two patients after five cycles. Glioma progression was noted in three patients after three, five, and five cycles, respectively. The 11 patients in whom some response was achieved had either an optic pathway tumor or a juvenile pilocytic astrocytoma. Twenty-six of the 32 patients had those characteristics, making the response rate in that group 42% (11 of 26 patients). Thirty-two patients received a total of 387 cycles of chemotherapy. Hematological toxicity was moderate. Twenty-one patients developed thrombocytopenia (platelet count < 50,000/μl); three patients required one platelet transfusion each. Nine patients developed neutropenia (absolute neutrophil count < 500/μl); one developed fever and required administration of antibiotic agents. One dose adjustment in each of the patients prevented further thrombocytopenia and neutropenia. Two patients with stable disease died of respiratory complications. One patient developed Grade III ototoxicity after receiving five cycles, one patient developed hypersensitivity to carboplatin, and none developed nephrotoxicity.
Carboplatin given at a dosage of 560 mg/m2 every 4 weeks has activity in patients with progressive LGG. This drug regimen is relatively simple and well tolerated. Further investigation and longer follow-up study are warranted.
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.
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.
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°).
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.
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.