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R Shane Tubbs

Publications and source records attributed to R Shane Tubbs.

At least 145 records · Page 8Linked to original sources
PubMed2004

Syringomyelia in twin brothers discordant for Chiari I malformation: case report.

Familial syringomyelia outside of trauma, tumor, or infection has been reported. Cases are presented that highlight the possible connection between familial syringomyelia and the Chiari 0 malformation. We report on 11-year-old twin brothers both with syringomyelia. Magnetic resonance imaging further revealed that one brother had Chiari I malformation and the other had Chiari 0 malformation. Both underwent posterior fossa decompression with radiologic improvement of their syringes. These case reports lend credence to earlier reports of improvement in syringomyelia following posterior fossa decompression in the absence of Chiari I malformation, the so-called Chiari 0 malformation. In addition, these case reports should influence the manner in which familial syringomyelia without tonsillar ectopia is defined and addressed, that is, posterior fossa decompression versus shunting of the syrinx, thereby addressing the potential cause of the syringomyelia and not only the enlarged cavity itself.

Arnold-Chiari Malformation↗
PubMed2004

Can the conus medullaris in normal position be tethered?

Many have equated the term tethered spinal cord to a conus that is pathologically elongated. Most authorities have declared radiologic coni located inferior to the L-2 as pathologic. However, we have described previously a small series of patients in whom symptoms of a tethered spinal cord were evident clinically yet radiologically the conus medullaris was found to lie at a widely acceptable normal anatomic site. Following a review of the extant literature prior to our publication in 1993, several authors had operated on patients for symptoms of a distally tethered spinal cord in whom a conus was found to terminate at a 'normal' vertebral level. We believe that there is indeed a subset of the tethered cord patient population in whom the tip of the conus lies at even liberally accepted normal levels. We would encourage clinicians treating patients with symptoms of tethered cord syndrome not to treat the patient based simply on imaging but imaging coupled with clinical symptoms and physical exam. It is important to point out that in lieu of the many publications of conus termination that one accepts that there is no one single 'normal' position of the terminal cord but rather a normal range. Perhaps a superior way of interpreting 'tethered' cord is to view this as tautness of the cord and not necessarily elongation of the distal cord in every case.

Animals↗
PubMed2004

Sports and pediatric cerebrospinal fluid shunts: who can play?

OBJECTIVE: The purpose of this study was to collect and review available data on the incidence of sport-related complications in children with cerebrospinal fluid (CSF) shunts. METHODS: After review of medical and legal literature revealed no reports on sports and shunts, an Internet-based survey was conducted of pediatric neurosurgeons. Observed complications, recommendations for sport participation, and shunt volume data were collected. RESULTS: Ninety-two providers (55% sample) responded. Seventy-seven percent had never observed a sport-related shunt complication in their practice. The remaining 23% witnessed an estimated total of 25 to 30 complications. Broken shunt catheters and shunt dysfunction were the most common complications observed. Only one acute intracranial hematoma was reported in the entire series. The incidence of sport-related CSF complications in children seems to be significantly less than 1%. Ninety percent of pediatric neurosurgeons do not restrict their patients' participation in noncontact sports. For contact sports, approximately one-third of neurosurgeons preclude all participation, whereas another third restrict specific sports. The final third of neurosurgeons surveyed do not restrict participation in contact sports for children with CSF shunts. CONCLUSION: Sport-related complications in children with CSF shunts are very uncommon.

Athletic Injuries↗
PubMed2004

Posterior cranial fossa volume in patients with rickets: insights into the increased occurrence of Chiari I malformation in metabolic bone disease.

OBJECTIVE: Some have proposed that the calvarial thickening seen in patients with rickets results in an increased rate of Chiari I malformation (CIM) in these patients. The present study measures the posterior fossa volume in children with rickets to verify previous case reports indicting a small posterior fossa as the cause for an increased rate of CIM in children with rickets. METHODS: Patients were chosen by use of a computer database to search for individuals diagnosed with rickets. Nineteen patients were identified with this diagnosis. Seven patients were found from this cohort to have imaging of the head. Axial computed tomographic and magnetic resonance images were analyzed by use of the Cavalieri method to define posterior fossa volumes. These data were then compared with those from age-matched control subjects. RESULTS: Mean volumes of the posterior fossa were significantly reduced in all patients compared with age-matched control subjects (P < 0.0001). CONCLUSION: We have found that the volume of the posterior fossa is significantly smaller in children with rickets versus age-matched control subjects. Furthermore, 29% of our study group had an associated CIM. We may hope that these data will aid in the further understanding of the pathophysiology of CIM in cases of metabolic bone disease.

Adolescent↗
PubMed2004

The accessory atlantoaxial ligament.

OBJECTIVE: The stability of the joints connecting the cranium to the upper cervical spine is of vital importance. The ligaments of this region, for the most part, have been thoroughly investigated, with the exception of the accessory atlantoaxial ligament. METHODS: Ten cadaveric specimens were examined to observe the anatomy of this ligament. RESULTS: This ligament was found in all specimens, and in each, it not only connected the atlas to the axis but also continued cephalically to the occipital bone. The approximate dimensions of this structure were 3 cm x 5 mm. Functionally, this ligament became maximally taut with a rotation of the head of 5 to 8 degrees. Laxity was observed with cervical extension, and maximal tautness was seen at 5 to 10 degrees of cervical flexion. CONCLUSION: The accessory atlantoaxial ligament seems to participate in craniocervical stability and perhaps should be renamed the accessory alar ligament or accessory atlantoaxialoccipital ligament; both of these terms better denote its anatomic characteristics. Perhaps in the future, better magnetic resonance imaging techniques and machines will be able to identify this structure so as to appreciate its integrity after upper cervical spine trauma.

Aged↗
PubMed2004

Delayed resolution of Chiari I-associated hydromyelia after posterior fossa decompression: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: The expected time interval for resolution of hydromyelia after Chiari I decompression is lacking in the literature. This case report highlights one instance of delayed resolution of Chiari-induced hydromyelia. CLINICAL PRESENTATION: We report an adolescent girl with a Chiari I malformation and hydromyelia. INTERVENTION: A suboccipital craniectomy and C1 laminectomy with intradural exploration and duraplasty were performed. Serial imaging at 1 and 2 years after posterior cranial fossa decompression with duraplasty demonstrated no change in the size of the hydromyelia. At 3 years after surgery and before reoperation for continued hydromyelia, repeat magnetic resonance imaging demonstrated significant diminution of the fluid cavity. If this hydromyelia did resolve as a result of surgery, the interval for radiological observation clearly needs to be reconsidered. CONCLUSION: Unfortunately, this is an area in which the literature is lacking. With this case as a nidus, studies are now necessary to determine the range of time necessary for Chiari I malformation-related hydromyelia to resolve.

Adolescent↗
PubMed2004

Intramedullary hemorrhage in a neonate after lumbar puncture resulting in paraplegia: a case report.

We present the case of a premature infant with decreased spontaneous movement of the lower extremities. Imaging was demonstrative of a lesion of the conus medullaris. Operatively and with histologic confirmation, the mass was determined to be a blood clot originating from the conus. Retrospectively, the patient had a known lumbar puncture. There were no clotting abnormalities in this patient. At long-term follow-up, the child continues to have lower extremity paresis and incontinence of bowel and bladder. Clinicians should consider the lower termination of the conus medullaris in the infant, especially in the preterm infant.

Hematoma↗
PubMed2004

Isolated flat capillary midline lumbosacral hemangiomas as indicators of occult spinal dysraphism.

OBJECT: Historically, cutaneous stigmata representative of occult spinal dysraphism (OSD) have included lumbar hemangiomas. Frequently, this skin change is found in conjunction with other cutaneous alterations such as dermal sinus tracts and subcutaneous lipomas. Debate has recently surrounded the question of whether these skin changes in isolation might indicate underlying spinal disease. The authors reviewed their experience in their most recent 120 cases in which OSD was diagnosed. METHODS: The authors retrospectively reviewed records obtained in 120 patients with OSD. They found that many of the patients reviewed harbored only a flat capillary hemangioma as an indicator of OSD. In 21 patients (17.5%) with only midline lumbosacral flat capillary hemangiomas, underlying OSD was present. No single variety of OSD had a higher incidence of association with this single cutaneous stigma. CONCLUSIONS: Based on their experience, the authors recommend magnetic resonance (MR) imaging evaluation in cases involving this skin lesion in isolation to discern the potential for surgically significant spinal cord anomalies. Prospective studies are now needed to examine MR images obtained in all children with this lesion in the midline lumbosacral spine and assess for OSD.

Child↗
PubMed2004

Efficacy of scheduled nonnarcotic analgesic medications in children after suboccipital craniectomy.

OBJECT: The authors performed a study to evaluate the efficacy of a regimen of scheduled minor analgesic medications in managing postoperative pain in children undergoing intracranial procedures. METHODS: Postoperative pain scores were analyzed in two groups of children who underwent decompressive surgery for Chiari malformation: Group A underwent a scheduled regimen of minor oral analgesic medications (standing doses of acetaminophen [10 mg/kg] and ibuprofen [10 mg/kg] alternating every 2 hours) and Group B received analgesic medication when requested. Fifty children underwent a standard occipital craniectomy (25 in each group). The pain scores were significantly lower in Group A during most of the postoperative period. Length of stay (LOS) was shorter (2.2 compared with 2.8 days), and narcotic and antiemetic requirements were also lower in Group A patients than in Group B patients. Patients with spinal cord syringes exhibited a similar postoperative status to those without, and similar improvements in pain scores with scheduled minor analgesic medications were also evident. CONCLUSIONS: A regimen of minor analgesic therapy, given in alternating doses every 2 hours immediately after craniotomy and throughout hospitalization, significantly reduced postoperative pain scores and LOS in children in whom suboccipital craniotomy was performed. Narcotic and antiemetic requirements were also decreased in association with this regimen. Application of this postoperative analgesia protocol may benefit children and adults in whom various similar neurosurgical procedures are required.

Acetaminophen↗
PubMed2004

Cessation of chronic hypertension after posterior fossa decompression in a child with Chiari I malformation. Case report.

The authors report on the case of a patient evaluated for Valsalva maneuver-induced headache, dizziness, and ataxia. Neuroimaging revealed a Chiari I malformation without syringomyelia. A history of idiopathic hypertension was noted. After posterior fossa decompression, pathologically elevated blood pressure was absent, and at 24-month follow-up evaluation the patient remained normotensive. Although seemingly rare, this case illustrates that some patients with tonsillar ectopia may exhibit elevated blood pressure. Clinicians should consider hindbrain herniation a rare cause in idiopathic hypertension.

Adolescent↗
PubMed2004

Neuroendoscopic findings in patients with intracranial germinomas correlating with diabetes insipidus.

OBJECT: Intracranial germinomas commonly occur in the pineal region, the floor of the third ventricle (hypothalamus), or both, and they are often associated with diabetes insipidus (DI). The authors conducted a study to correlate preoperative DI with the endoscopic and magnetic resonance (MR) imaging evidence of tumor on the third ventricle floor. METHODS: The authors reviewed hospital records, office charts, and MR imaging studies obtained in patients in whom a biopsy sampling procedure was performed with or without endoscopic third ventriculostomy (ETV) at Children's Hospital, Birmingham, Alabama between May 1998 and July 2002. Ten patients with the pathological diagnosis of pure germinoma were identified. Preoperative MR imaging findings and presenting symptoms were correlated with intraoperative neuroendoscopic findings. Seven patients presented with symptomatic hydrocephalus and underwent concomitant ETV. Six patients presented with DI and MR imaging evidence of involvement of the third ventricle floor. Two patients presented with DI and no initial MR imaging evidence of neoplastic involvement of the third ventricle floor; in both there was endoscopic evidence of neoplastic involvement of the floor of the third ventricle. In two children without DI, neither MR imaging nor endoscopic evidence of involvement of the third ventricle floor was observed. CONCLUSIONS: In the authors' experience with intracranial germinoma, endoscopic tumor biopsy sampling, and ETV provide an effective, safe, and minimally invasive means of obtaining diagnostic tissue and treating any concomitant hydrocephalus. The authors found that preoperative DI is an absolute predictor of neoplastic involvement of the hypothalamus regardless of MR imaging findings. Therefore, in the setting of DI and intracranial germinoma without neuroimaging evidence of hypothalamic involvement, germinomatous involvement of the hypothalamus should be assumed present, if not confirmed endoscopically at the time of biopsy sampling or third ventriculostomy, when devising adjuvant treatment plans for such patients.

Adolescent↗
PubMed2004

Persistent syringomyelia following pediatric Chiari I decompression: radiological and surgical findings.

OBJECT: The incidence of syringomyelia in patients with Chiari I malformation is reported to be between 20 and 75%. In the series reported herein 10.6% of patients with both clinical entities have continued to have a significant syrinx following their first decompressive procedure. All but one patient had resolution of their syrinx after a second posterior fossa operation. The authors have analyzed this smaller group of patients to look for possible radiological or surgical findings that may aid in predicting which patients are less likely to respond to the initial first decompressive procedure. METHODS: The authors retrospectively reviewed radiological and operative data in eight patients who continued to have syringomyelia following a decompressive procedure. Seven (88%) of these patients had complete resolution of their syrinx following a second operation. At repeated operation, obstruction at the foramen of Magendie was seen in six patients. In one patient in whom the dura was not opened during first operation, the second operation revealed an arachnoid veil that occluded the foramen of Magendie. CONCLUSIONS: No single radiological measurement was found to aid in the prediction of which patients would not respond to the first decompressive procedure. Furthermore, no operative finding was extraordinarily unique to any single patient. All but one patient in whom confirmation of a patent foramen of Magendie was made at repeated operation-that is, lysing of arachnoid veils, stent placement, unilateral tonsillar coagulation-had resolution of their syringomyelia. Surgical reexploration should be considered in cases of persistent syringomyelia.

Adolescent↗
PubMed2004

Arachnoid veils and the Chiari I malformation.

OBJECT: The literature contains scant data regarding variations in anatomy at the level of the foramen of Magendie in patients with Chiari I malformation and syringomyelia. METHODS: Based on their operative experience and hospital data, the authors detailed the incidence of arachnoid veils found in juxtaposition to the foramen of Magendie in patients with hindbrain herniation. Additionally, radiological studies were retrospectively reviewed in cases in which such an anomaly was noted intraoperatively. Of 140 patients with Chiari I malformation who underwent decompressive surgery, an associated syrinx was demonstrated in 80 (57%). The foramen of Magendie was obstructed by an arachnoid veil in 10 (12.5%) of these patients; once the lesion was punctured, the cerebrospinal fluid drained freely from this median aperture. On retrospective review of imaging studies, none of these anomalous structures was evident. In all patients with an arachnoid veil and syringomyelia resolution of syringomyelia was revealed on postoperative imaging. CONCLUSIONS: In the absence of a clear pathophysiology of syrinx production, the authors would recommend that patients with syringomyelia and Chiari I malformation undergo duraplasty so that, if present, these veils can be fenestrated.

Adolescent↗
PubMed2004

Magnetic resonance imaging evidence of posterior pharynx denervation in pediatric patients with Chiari I malformation and absent gag reflex.

OBJECT: The authors hypothesized that children with preoperative Chiari I malformation and an absent gag reflex may harbor pharyngeal musculature atrophy identifiable on magnetic resonance (MR) imaging. METHODS: Thirty patients with preoperative Chiari I malformation and a functioning gag reflex, five patients with preoperative Chiari I malformation and complete absence of gag reflex, and 50 control individuals underwent radiological measurement of the posterior pharyngeal wall thickness. The thickness of the posterior pharyngeal wall in age-matched controls was significantly thinner (p < 0.0001) than that in patients with Chiari I malformation and no functioning gag reflex. Additionally, in patients with hindbrain herniation and absent gag reflex, the posterior pharyngeal wall thicknesses were comparable to or thinner than those in age-matched controls. A general decrease in the thickness of the posterior pharyngeal wall was found in control individuals who were older compared with patients with Chiari I malformation and a preserved gag reflex in whom the prevertebral soft tissues were found to increase in thickness with age. Analysis of these data showed that in children with a nonfunctioning gag reflex the prevertebral soft tissue, composed primarily of the superior constrictor muscle, is statistically thinner compared with that in age-matched controls and age-matched children with Chiari I malformation and a functioning gag reflex. The authors theorize that the discrepancy between this measurement in controls and patients with hindbrain herniation is due to the thickening of the craniocervical ligaments that is known to occur in this clinical entity. CONCLUSIONS: The finding that prevertebral soft tissue thickens with age in patients with Chiari I malformation and functioning gag reflex alone may aid in the interpretation of soft-tissue injury following cervical spine injuries in this group.

Adolescent↗
PubMed2004

A critical analysis of the Chiari 1.5 malformation.

OBJECT: Although the traditional nomenclature used to describe hindbrain hernias is useful, there are certainly patients in whom these morphological entities do not strictly apply. One such group is composed of patients with the more recently described Chiari 1.5 malformation in which a Chiari I malformation is seen in combination with brain-stem herniation through the foramen magnum. In an attempt to elucidate further the best surgical strategy and to refine the descriptive terminology, the authors retrospectively analyzed all cases at their institutions in which this form of hindbrain herniation was diagnosed. METHODS: The authors reviewed the database for all patients in whom Chiari 1.5 malformation had been diagnosed. Each patient had undergone a posterior fossa decompressive surgery. Magnetic resonance images were evaluated for the extent of caudal descent of the brainstem, amount of tonsillar ectopia, inclination of the odontoid process, and any brain or brainstem abnormalities. Clinical presentations and postoperative results were correlated to the aforementioned radiological findings. Twenty-two patients were identified. The obex was a mean 14.4 mm inferior to the foramen magnum, and the medulla exhibited a flattened appearance in the midsagittal plane in all patients. Syringomyelia was documented in 50% of the cases. The cerebellar tonsils were found to lie at C-1 and C-2 in nine and 13 patients, respectively. The mean angulation of the odontoid process was 84.4 degrees. No abnormalities or caudal descent of the midbrain or pons was identified. Eighteen patients experienced resolution of preoperative symptoms. Persistence of syringomyelia prompted a second posterior fossa operation secondary to progressive scoliosis in 13.6% of the patients. CONCLUSIONS: No single sign or symptom was found to be peculiar to the Chiari 1.5 malformation, although all patients in whom this diagnosis was established had undergone a posterior fossa decompressive surgery. A significant number (13.6%) of patients required repeated operation for persistent syringomyelia. Neurosurgeons may wish to consider that many patients may not respond as well to posterior fossa decompressive surgery especially if syringomyelia is present.

Adolescent↗
PubMed2004

Acquired Chiari I malformation following baclofen pump placement in a child. Case report.

The authors present a case of a child suffering from shunt-treated hydrocephalus and spastic quadriplegia who underwent surgery for placement of a baclofen pump. Magnetic resonance (MR) imaging performed prior to pump placement demonstrated no hindbrain herniation. Afterward, however, the patient exhibited symptoms of brainstem compression, and MR imaging revealed a significant Chiari I malformation along with a fully functioning ventriculoperitoneal shunt. Posterior fossa decompression was performed, and the patient's symptoms abated. The authors believe this to be the first report of an acquired Chiari I malformation in a patient with a baclofen pump. Clinicians should consider Chiari I malformation as a rare but severe complication of baclofen pump placement.

Adolescent↗
PubMed2004

The relationship of the spinal cord to scoliosis.

The authors present an original description of the tethered spinal cord. This submission in its day was not welcomed by the contemporaries of Dr. Robert Heimburger who theorized that there may be an association between the tethered spinal cord and scoliosis. Today we know that abnormal curvatures of the spinal cord can result from distal abnormal tensions placed on the spinal cord. This historical paper, now printed in full, may very well be one of the earliest descriptions of this association. It offers a unique window into the early cause-and-effect thinking regarding this neurosurgical lesion.

Adolescent↗