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Biomedical subjects

R Shane Tubbs

Publications and source records attributed to R Shane Tubbs.

At least 163 records · Page 9Linked to original sources

Lumbosacral agenesis and anteroposterior split cord malformation in a patient with single central maxillary incisor: case report and review of the literature.

We report an infant born with lumbosacral agenesis, a subcutaneous lumbosacral mass, and a solitary median maxillary incisor. Operatively, a lipomyelomeningocele was noted to extend from the dorsal hemicord of a split cord malformation. Genetically, the child was found to have a defect on chromosome 7q. To our knowledge, this is the first case report of a patient with the rare lumbosacral agenesis and solitary median maxillary incisor. Furthermore, to our understanding, this is only the fourth reported case of split cord malformation in which the hemicords are oriented in the sagittal plane and one of only a few cases reported in the medical literature of simultaneous occurrence of lumbosacral agenesis and occult spinal dysraphism, that is, split cord malformation and lipomyelomeningocele. Following a review of the medical literature, and considering that our patient did indeed have dysmorphology of chromosome 7q, we hypothesize that this single defect resulted in both cranial and caudal deformation, as exemplified by our patient. We review the medical literature for related case reports and potentially related chromosomal abnormalities and various teratogenic substances.

Abnormalities, Multiple↗

Split cord malformation and situs inversus totalis: case report and review of the literature.

INTRODUCTION: Situs inversus is a rare condition of visceral transposition in which the spinal axis is rarely affected. CASE REPORT: The authors report a patient with situs inversus totalis and type II split cord malformation. This patient had no complaints and presented with scoliosis. CONCLUSIONS: Recent compelling evidence from animal models and human case reports has led to hypotheses that defects of the midline and laterality defects (e.g., situs inversus) are etiologically related. Confirmation from additional case reports of situs inversus and split cord malformation could prove useful in determining a genetic locus for split cord malformations or implicating various chemical agents that are known to produce situs inversus as potential causative factors in the production of split cord malformations.

Child↗

Intracranial anatomic asymmetry in situs inversus totalis.

Situs inversus is a rare condition in which the position of the thoracic and the abdominal viscera are exchanged from the left to the right sides. A possible inversion of normal dominant intracranial anatomy, has however, rarely been discussed. We examine here the gross anatomy of an elderly cadaveric female for a possible "situs inversus" of the intracranial contents. This study has found that many structures commonly dominant on one side in the intracranial compartment were reversed in this specimen. These findings support the concept that a reversal of more commonly found intracranial anatomy may occur in situs inversus totalis, and this should alert the clinician performing invasive procedures in this population. These data will also hopefully provide further insight into possible mechanisms that contribute to situs inversus totalis.

Aged↗

Cranial deformation.

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Craniofacial Abnormalities↗

Cutaneous manifestations and the Chiari I malformation.

This article presents a child with Chiari I malformation and cutis marmorata telangiectatica congenita and reviews the medical literature regarding Chiari I malformation and other cutaneous disorders. In addition to cutis marmorata telangiectatica congenita and Chiari I malformation, our patient exhibited hemihypertrophy, Tourette's syndrome, scoliosis, obsessive-compulsive disorder, and seizures. Other associated findings seen in patients with Chiari I malformation include basilar invagination, Klippel-Feil syndrome, atlantoaxial assimilation, scoliosis from an underlying syrinx, and hydrocephalus.

Arnold-Chiari Malformation↗

Accessory obturator nerves with bilateral pseudoganglia in man.

During the routine dissection of the pelvis and anterior thigh of an adult female cadaver, accessory obturator nerves were found bilaterally with pseudoganglia. In addition, each accessory obturator nerve rejoined the anterior division of the normally placed obturator nerves after traveling superficial to the pubic bones. Histological sections revealed primarily normal nerve with no neuronal cell bodies within these focal areas of enlargement. No inflammatory response was noted in these histologically normal peripheral nerve structures. Further gross anatomy including other peripheral nerves was found to be normal. Peripheral nerve "ganglia" are found in the literature with little focus on histology. Our case report represents to our knowledge, the first report of a pseudoganglion in association with an accessory obturator nerve.

Adult↗

Chorda dorsalis.

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Child↗

Late gestational intrauterine myelomeningocele repair does not improve lower extremity function.

OBJECTIVE: To determine whether intrauterine myelomeningocele repair performed at between 20 and 28 weeks gestation improves lower extremity function (LEF). METHODS: Thirty-seven consecutive patients who had undergone intrauterine repair of their myelomeningocele at Vanderbilt University Medical Center had their lower extremity function and radiographic level (first defective vertebral level) compared to these same parameters in 40 controls who had undergone traditional postgestational repair of their myelomeningocele at the Children's Hospital in Birmingham, Ala., USA. RESULTS: Of all 77 patients (controls and study group), 13 had a LEF that matched their radiographic level, 27 had a LEF that was rostral to their radiographic level, and 37 had a LEF that was caudal to their radiographic level. Further stratification revealed that for the intrauterine repaired myelomeningoceles, 11% had no difference between LEF and radiographic level, 43% had a LEF that was rostral to their radiographic level, and 46% had a LEF that was caudal to their radiographic level. For those closed in a traditional manner, LEF matched their radiographic level, was rostral to their radiographic level, and was caudal to their radiographic level in 22.5%, 27.5%, and 50% respectively. However, the overall mean differences between institutions produced a p-value of 0.2026 (paired t-test). CONCLUSIONS: Although the current timing of intrauterine myelomeningocele repair has been found to lessen the degree of herniation of the rhombencephalon and reduce the incidence of shunt-dependent hydrocephalus, it does not statistically improve LEF. Parents should be advised of these findings prior to surgical intervention so as to focus their expectations.

Female↗

Reformation of the posterior atlanto-occipital membrane following posterior fossa decompression with subsequent constriction at the craniocervical junction.

The posterior atlanto-occipital membrane (PAO) contributes little to craniocervical stability and is generally underappreciated and incised with most suboccipital craniectomies. We report a case of a child who underwent posterior fossa decompression for Chiari I malformation with syringomyelia whose symptoms had not resolved months after surgery. A secondary exploratory operation revealed a healed constricting PAO which had been incised linearly at the initial operation. This patient's symptoms improved soon after the second surgery. We propose that attention be given to this membrane, and if it is incised with underlying dura mater as in a standard posterior fossa decompression, it should be removed or cauterized separately and laterally to inhibit its reformation.

Arnold-Chiari Malformation↗

Hemihypertrophy and the Chiari I malformation.

We report two children with hemihypertrophy and Chiari I malformation (CIM) and review the extant medical literature regarding CIM and overgrowth disorders. We propose that these two entities do not represent a spurious association but rather share a common dysembryology of mesoderm.

Arnold-Chiari Malformation↗

Life expectancy of ventriculosubgaleal shunt revisions.

The subgaleal shunt has been and is currently used for the temporary bypass of the normal cerebrospinal fluid (CSF) pathways. We retrospectively reviewed all subgaleal shunts placed at the Children's Hospital, Birmingham, Ala., USA, from 1993 to the present and examined the life expectancy of revisions of this temporary method of CSF diversion. The average length of survival of primary, secondary and tertiary subgaleal shunts in this population was 37.4, 32.4 and 19.6 days, respectively. This current review demonstrates that the majority of patients in whom a subgaleal shunt is utilized may continue to obtain therapeutic diversion of their CSF for greater than 2.5 months with intermittent subgaleal shunt revisions. In the majority of cases, this length of time is sufficient to manage and resolve issues that would make ventriculoperitoneal shunting undesirable.

Adolescent↗

Children with growth hormone deficiency and Chiari I malformation: a morphometric analysis of the posterior cranial fossa.

OBJECTIVE: The posterior fossa (PF) has been found to be small in various forms of Chiari malformation. Explanations involving a connection between growth hormone deficiency (GHD) and Chiari I malformation (CIM) have been proposed. However, to date, no quantitative analysis of the PF of patients with CIM and GHD has been performed. Our study was performed to determine the geometry of the PF in children with GHD and CIM. METHODS: Morphometric analysis of the PF was performed in 10 children with GHD and CIM (group 1), 20 children with GHD and no CIM (group 2) and 50 controls. RESULTS: PF volumes for group 1 ranged from 128 to 259 +/- 33 ml, and for group 2, they ranged from 115 to 186.2 +/- 25.4 ml. Lengths of the foramen magnum for groups 1 and 2 had means of 36 and 38 mm, respectively. The mean basiocciput length and tentorial angle for groups 1 and 2 were 20 and 19 mm and 89 and 87.5 degrees, respectively. CONCLUSIONS: We have determined that children with GHD with or without CIM have no significant difference in their PF volume compared to controls. However, our data demonstrate significant underdevelopment of portions of the bony PF in both patients with GHD alone and in patients with GHD and CIM. Tentorial angles were elevated in noncontrol groups. We propose that this association is not due to an increased rate of 'midline' defects seen in GHD but rather a structurally distorted PF that is not capacious enough to house the entire developing rhombencephalon. These data will hopefully aid in the further understanding of the pathophysiology of CIM.

Adolescent↗

Alternative uses for the subgaleal shunt in pediatric neurosurgery.

The subgaleal shunt has been used for the temporary bypass of the normal cerebrospinal fluid (CSF) pathways. We retrospectively reviewed all subgaleal shunts placed at the Children's Hospital, Birmingham, Ala., USA, from 1997 to the present and examined all uses (e.g. indication, length of follow-up) of the subgaleal shunt outside its use for temporary CSF diversion in premature infants with intraventricular hemorrhage and subsequent hydrocephalus. The average length of survival of the primary subgaleal shunt in this population was 32.2 days. We have had good success with subgaleal shunts in children with malignant brain tumors, intraventricular abscesses, chronic truncal wounds, chronic subdural hygromas and meningitis. However, the greatest utility has been in those scenarios in which the peritoneal cavities were not currently, but with time would be, candidates for distal shunt implantation. Examples of these instances are patients with hydrocephalus and necrotizing enterocolitis or hydrocephalus and preoperative abdominal wall pathology such as omphalocele.

Brain Diseases↗