Tethered spinal cord with double spinal lipomas

Tethered spinal cord tension assessed via ultrasound elastography in computational and intraoperative human studies

BACKGROUND

Tension in the spinal cord is a trademark of tethered cord syndrome. Unfortunately, existing tests cannot quantify tension across the bulk of the cord, making the diagnostic evaluation of stretch ambiguous. A potential non-destructive metric for spinal cord tension is ultrasound-derived shear wave velocity (SWV). The velocity is sensitive to tissue elasticity and boundary conditions including strain. We use the term Ultrasound Tensography to describe the acoustic evaluation of tension with SWV.

METHODS

Our solution Tethered cord Assessment with Ultrasound Tensography (TAUT) was utilized in three sub-studies: finite element simulations, a cadaveric benchtop validation, and a neurosurgical case series. The simulation computed SWV for given tensile forces. The cadaveric model with induced tension validated the SWV-tension relationship. Lastly, SWV was measured intraoperatively in patients diagnosed with tethered cords who underwent treatment (spinal column shortening). The surgery alleviates tension by decreasing the vertebral column length.

RESULTS

Here we observe a strong linear relationship between tension and squared SWV across the preclinical sub-studies. Higher tension induces faster shear waves in the simulation (R2 = 0.984) and cadaveric (R2 = 0.951) models. The SWV decreases in all neurosurgical procedures (p < 0.001). Moreover, TAUT has a c-statistic of 0.962 (0.92-1.00), detecting all tethered cords.

CONCLUSIONS

This study presents a physical, clinical metric of spinal cord tension. Strong agreement among computational, cadaveric, and clinical studies demonstrates the utility of ultrasound-induced SWV for quantitative intraoperative feedback. This technology is positioned to enhance tethered cord diagnosis, treatment, and postoperative monitoring as it differentiates stretched from healthy cords.

Congenital Spinal Lipomatous Malformations. Part 1. Spinal Lipomas, Lipomyeloceles, and Lipomyelomeningoceles

Background: Lumbosacral spinal lipomas and lipomyeloceles are usually identified in early childhood. Terminology, histopathology, and diagnosis for these malformations can be confusing. Materials and Methods: This is a PubMed review with comparison of embryology, gross, and histopathology, and reporting requisites for these and related closed spinal malformations. Results: The spinal lipoma group (congenital spinal lipomatous malformations) includes subcutaneous, transdural, intradural, and noncontiguous malformations stretching through the entire lower spinal region. This lipomyelocele trajectory overlaps the embryonic tail's caudal eminence. Histopathologically, the lipomyelocele spectrum is a heterogeneous, stereotypical set of findings encountered from dermis to spinal cord. Diagnosis requires detailed correlation of images, intraoperative inspection, and histopathology. Conclusions: Appropriate terminology and clinicopathologic correlation to arrive at a diagnosis is a critical activity shared by pathologist and clinician. Prognostic and management differences depend on specific diagnoses. Familial and genetic influences play little if any role in patient management in closed spinal malformations.

Split Cord Malformation Type 2 with Double Dorsal Lipoma: A Sequela or a Chance

An 11-month-old baby girl, with normal perinatal history, presented with a congenital lumbosacral swelling and a sacral dimple. Imaging revealed a split cord malformation (SCM) type 2 at L1–L3 with a lipomeningocoele extending intradurally and tethering both the hemicords, the conus was noted to be at L4. She underwent excision of the lipoma and detethering of the hemicords. Intraoperatively, the split cord was seen from L1 to L3 with an aberrant median vessel passing between the hemicords. Two lipomas were seen separately attached to each of the hemicords, the lipomas were dissected off the hemicords, and the hemicords were neurulated. The case helps revisit the unified theory proposed by Pang for SCM as well as the theory of premature disjunction in the pathogenesis of lipomeningocoele. Formation of the endomesenchymal tract splits the developing cord into two, whereas the premature detachment of neuroectoderm from the cutaneous ectoderm can lead to lipomeningocoeles. The present case is only the fourth case ever reported of an SCM type 2 with double lipoma. In the case report, we discuss the embryological basis of this condition and surgical nuances of management.

Cystic Cervical Dysraphism: Experience of 12 Cases

Introduction:

Cystic spinal dysraphism of the cervical region is a relatively rare entity, which is more frequently associated with congenital anomalies such as split cord malformation, Chiari malformation, and corpus callosum agenesis, when compared to their lumbosacral counterpart. In our study, we have highlighted the clinical spectrum, associated anomalies (both neural and extra-neural), and surgical nuances of these.

Materials and Methods:

This study is a retrospective analysis of 225 patients from June 2010 to April 2017. Twelve patients who were between the age of 1 month and 16 years were included in our study. Average age was 32.6 months, and there were five female patients and seven male patients. All patients underwent neurological and radiological examinations followed by surgical excision of the sac and exploration of the intradural sac using the standard microsurgical technique. Neurological, Orthopedic and urological outcomes were studied in our description.

Results:

Of the 12 cases, 9 patients (75%) had some associated anomaly. Four of the 12 patients (25%) had split cord malformation, 3 had corpus callosum agenesis, and 5 had Chiari malformation. Patients with cervical spina bifida cystica (SBC) present with less neurologic deficits and greater association with CCA.

Conclusion:

The management strategy and association with other congenital anomalies separates cervical dysraphism as a different clinical entity rather than just group. These patients rather show favorable outcome with regard to neurologic, orthopedic, and urologic problems as compared to their caudal counterpart. Early surgical intervention even before the onset of symptoms is recommended. A proper radiological and urological evaluation is warranted.

Noncontiguous Double Spinal Lipoma with Tethered Cord and Polydactyly: Two Different Embryological Events in One Patient

Lumbosacral lipoma is reported to occur in 4–8 of 100,000 patients. Sixty-six percent of lipomyelomeningocele in young patients have accompanied by hypertrophic filum terminale. It is rare to find two isolated spinal lipomas simultaneously. Embryological origin of dorsal and filar lipomas is different from each other and hence rarer to find them together. Radical resection is now being preferred for better long-term progression-free survival. We report an interesting case of spinal dysraphism in a 4-month-old female child with protruding, nontender, soft, subcutaneous 5 cm × 7 cm mass of the lumbosacral area that had been present since birth. Other anomalies included polydactyly of left hand. Magnetic resonance imaging demonstrated two isolated spinal lipomas, a transitional type and a terminal type filum lipoma with an interval of normal filum between the two. The findings were confirmed at surgery and detethering done along the white plane with neural placode reconstruction as described by Dachling Pang. The child had an uneventful postoperative recovery.

Tethered cord with tandem lipomyelomeningoceles, split cord malformation and thick filum

Lipomyelomeningocele, a closed neural tube defect, usually occurs in lumbosacral area as a single lesion but can be associated with other spinal dysraphism. We report an infant with a very rare presentation of tandem lumbosacral lipomyelomeningoceles, thick filum terminale and split cord malformation.

Unusual presentation of congenital dermal sinus: tethered spinal cord with intradural epidermoid and dual paramedian cutaneous ostia

The authors present the first report of spinal congenital dermal sinus with paramedian dual ostia leading to 2 intradural epidermoid cysts. This 7-year-old girl had a history of recurrent left paramedian lumbosacral subcutaneous abscesses, with no chemical or pyogenic meningitis. Admission MRI studies demonstrated bilateral lumbar dermal sinus tracts and a tethered spinal cord. At surgery to release the tethered spinal cord the authors encountered paramedian dermal sinus tracts with dual ostia, as well as 2 intradural epidermoid cysts that were not readily apparent on MRI studies. Congenital dermal sinus should be considered in the differential diagnosis of lumbar subcutaneous abscesses, even if the neurocutaneous signatures are located off the midline.

Split cord malformation Type II with twin dorsal lipomas

Although uncommon, variations in split cord malformation (SCM) have been described. However, a combination of SCM Type II and dorsal lipomas has not been reported. The authors describe the case of a 6-year-old girl who presented with a 1-year history of spastic paraparesis associated with a lipomatous swelling on her lower back. Radiology revealed a Type II SCM with a dorsal lipoma at that level. Intraoperatively, the authors observed a dorsal lipoma for each hemicord; these were excised, and the septum causing the split was cut. Premature separation of the cutaneous and neural ectoderm is predetermined for each neural fold, and a split at this level would give rise to SCM with twin dorsal lipomas, one for each hemicord.

Unusual association of tethered cord, filum terminale lipoma, and myxopapillary ependymoma

STUDY DESIGN

Case report.

OBJECTIVE

We report a 67-year old man with a known filum terminale lipoma causing a tethered cord extending to the subcutaneous fat tissue and a newly diagnosed concomitant ependymoma, revealed on lumbar magnetic resonance imaging (MRI).

SUMMARY OF BACKGROUND DATA

The coexistence of filum terminale lipoma and ependymoma is very rare. The underlying reason of this coexistence is still unknown. The patients with known filar lipoma causing a tethered cord can be underdiagnosed clinically even though new symptoms develop.

METHODS

Case study with lumbar MRI.

RESULTS

The patient was operated, and both of the ependymoma and filum terminale lipoma were removed. The pathologic examination was consistent with the MRI findings. Three months after surgery, the patient improved significantly.

CONCLUSION

The coexistence of filum terminale lipoma and ependymoma is rare. Patients with relevant symptoms may be referred for an MRI study; however, especially patients with known filar lipomas causing tethered cord may be missed. Therefore, including these patients, a contrast-enhanced lumbar MRI must be performed to exclude any coexistence of filum terminale lipoma and ependymoma in the early course of the disease which can also help the surgeon in guiding the appropriate treatment.