Surgically confirmed myelographic classification of congenital intraspinal lipoma in the lumbosacral region

Surgery for spinal cord lipomas

OBJECTIVES

To analyze the results after surgery for spinal cord lipomas.

METHODS

The authors report their results of management of 63 non consecutive random children with spinal cord lipomas treated over a period from 2001 to 2005, at the All India Institute of Medical Sciences, New Delhi, India, a tertiary care neurosurgical centre.

RESULTS

There were 63 cases consisting of 32 (52%) conus lipomas, 14 (22%) filum lipomas, 14 (22%) lipomeningomyelocele (lipoMMC), 2 (2.5%) cases of lipomyelocystocele and one (1.5%) case of mixed lipoma. None of the patients who were asymptomatic before surgery deteriorated neurologically, irrespective of the type of lipoma till the last follow up. In those patients with preexisting neurological deficits, the improvement in motor, sensory and bladder abnormalities was only to an extent of 15 %, 16 % and 21 % respectively. None of the children with preexisting neurological deficit regained overall normal function. Nevertheless, the improvement in symptoms after surgery made the patients lead a better social life. Only 6 % of patients developed deterioration in neurological function after surgery, all of them occurring in patients already having pre-operative deficits.

CONCLUSIONS

The authors recommend prophylactic surgery which is safe and effective in preventing neurological deficits, irrespective of the type of lipoma. Most of the patients benefit only to some extent even after surgery, once they develop neurological dysfunction. A close long term follow up is recommended in order to detect neurological deterioration even in children operated prophylactically.

Diagnosis, outcome, and management of fetal abnormalities: fetal hydrocephalus

INTRODUCTION

It has been recognized that the morphological fetal CNS findings detected in early development are not always the final features: occasionally they may not be determined in diagnosis and may change developmentally or chronologically during the fetal life in utero.

DISCUSSION

Certain factors of the fetal chronology of CNS anomalies can cause irreversible changes during fetal life. These include: significant delay in the neuronal maturation process in fetal hydrocephalus developed in clinico-embryological stage II of the Perspective Classification of Congenital Hydrocephalus (PCCH), secondary neural injury in the intactly developing spinal cord above the neural placode in fetuses with spina bifida aperta (myeloschisis), histological "evolution" of tumors or dysgenetic CNS, and deformity of the normally developed intracranial or intraspinal CNS structures. Considering the current status of fetal surgery in general and technical advances promising improved outcomes, fetal neurosurgery can also be applied to the above-mentioned progressive pathology or pathophysiology in the fetal CNS. However, since the failure of the first trial of fetal neurosurgery in the 1980s, the prerequisites have still not been clarified. In order to use advanced neurosurgery techniques in the management of fetal CNS anomalies, these prerequisites have to be established.

Intramedullary spinal tumors of disordered embryogenesis

Abnormal spinal embryogenesis is quite commonplace. While greater than 90 percent of these errors of embryogenesis leads to occult spinal dysraphism with minimal neurologic or orthopedic sequelae, there is a significant minority of these anomalies which leads to the formation of the so-called 'congenital tumors of disordered embryogenesis'. The purpose of this article is to discuss the embryology, presentation, diagnosis and management of the spinal dysraphic states with particular emphasis on those errors which lead to mass lesions in the spinal canal such as dermoids, epidermoids, lipoma/lipomyelomeningocoele and neurenteric cysts. We also include lesions such as dermal sinus tracts and thickened filum terminale in our discussion with particular emphasis on their relationship to the tethered cord syndrome. Proper surgical management of these various conditions necessitates a thorough understanding of their embryologic etiology and the anatomic/physiologic ramifications that such lesions have on the developing spinal cord.

Syringomyelia secondary to congenital intraspinal lipoma

Preoperative evaluation using serial magnetic resonance imaging was performed on an infant with lumbosacral lipoma. Syrinx formation arising just above the lipoma was observed in conjunction with rapid growth of the lipoma. Definite shrinkage of syringomyelia was obtained after radical excision of the lipoma. The syrinx formation was possibly caused by compression from the extramedullary lipoma.

Spinal cord abnormalities in caudal regression syndrome

Caudal regression syndrome includes malformations ranging from mild forms of sacral agenesis to severe limb anomalies referred to as sirenomelia. The latter, in addition to sacral anomalies, shows malformed single lower limb and agenesis of rectum and genitourinary tracts. We report the neuropathologic examination in four infants, three with sirenomelia and one with lumbosacral agenesis. Brain and spinal cord were normal except for the structures in the caudal region of the spinal cord that were abnormal in all four cases. The first sirenomelic case with a mild sacral hypoplasia had only minor fusion of a few sacral roots and a slightly low-positioned conus medullaris. The second sirenomelic case with an intermediate degree of sacral hypoplasia had fusion of some of the sacral roots and ganglia, spinal ganglion cell heterotopias, filar lipoma and absence of the last sacral roots and ganglia. The third sirenomelic case with a severe degree of sacral hypoplasia showed additional tethering of the spinal cord. Case four with the agenesis of the lumbosacral spine had a total lack of the lumbosacral spinal cord, and dysplasia of the T11 and T12 cord segments. These findings suggest that the extent of anomalies of the caudal spinal cord structures in the caudal regression syndrome are roughly proportional to the anomalies of the vertebral column, and that they may constitute some of the main components of this syndrome.

Leptomyelolipoma: analysis of 20 cases

Leptomyelolipoma (lumbosacral lipoma) is a common form of spinal dysraphism. The deficits produced include sensory, motor, bowel, and bladder dysfunction, and vary in incidence between the pediatric and adult populations. Twenty patients treated surgically at the Mount Sinai Hospital between 1972 and 1988 are reviewed. Fifty percent were 12 years of age or less and 50% were older than 18 years of age. The surgical approach was designed to accomplish untethering of the conus medullaris, debulking of the lipomatous mass compressing the cord, reconstruction of the dural canal, and reapproximation of the paraspinal muscles and lumbosacral fascia to prevent future trauma. Postoperatively, no patient experienced deterioration of neurological function. Of the symptomatic patients. 67% displayed dramatic improvement or became asymptomatic and 33% experienced stabilization of their deficits. The symptoms most resistant to surgical correction were orthopedic foot deformities and bowel dysfunction, whereas bladder dysfunction, motor weakness, and radiculopathies were most amenable to surgical therapy. Early surgical repair is recommended in these cases to forestall irreversible neurological damage.

Tethered cord syndrome versus low-placed conus medullaris in an over-distended spinal cord following initial repair for myelodysplasia

We present findings obtained from a total of 100 patients who had previously undergone surgery for spina bifida and whose progress had been monitored by magnetic resonance imaging (MRI) in our meningomyelocele clinic. Fourteen of these patients (14.0%) developed delayed symptom(s) of progressive spinal neurologic dysfunction. In those with myeloschisis, increase of motor deficit was the most common clinical manifestation during infancy and early childhood (mean age: 6.8 years), whereas pain on back flexion was seen in patients who were over 15 years of age (mean age: 17.3 years). MRI carried out in myeloschisis patients invariably demonstrated that the conus medullaris was in an abnormally low position, suggesting over-distension of the spinal cord. This was irrespective of whether symptom(s) developed or not and did not correlate with the initial surgical procedure (reconstructive or otherwise) used. Patients with symptom(s) were revealed by MRI to have an extremely low conus set at the spinal level of S-1 or below; neurological examinations showed that the motor deficit occurred at high levels in the spine. Results from lipomeningocele patients were more erratic in terms of conus position and delayed development of neurological defects.(ABSTRACT TRUNCATED AT 250 WORDS)