Lumbar reconstruction with hyperlordotic cages: Prediction of neuroforaminal height in comparison to established age and sex dependent reference values

Interbody cages are routinely used in lumbar reconstruction surgery of deformity cases for restoration of lordosis and sagittal balance of the spine. However, if hyperlordotic implants are inserted into the intervertebral space, special consideration has to be taken concerning the height of the neural foramen during cage implantation. The greater the lordotic angle of the cage is, the higher the posterior size of the cage needs to be in order to avoid neuroforaminal nerve root impingement. In this technical communication, we propose and clinically validate a stepwise mathematic model to predict neuroforaminal height in patients undergoing lumbar reconstruction with hyperlordotic cages. The length of the superior and inferior vertebral end plates including the height of the neural foramen are measured before implantation of the cage in standing sagittal view x-rays. By assumption of an isosceles triangle in combination with the posterior height and the lordotic angle of the cage, the neuroforaminal height after cage implantation can be estimated. By comparison of the predicted neuroforaminal height with age and sex dependent reference values, nerve root impingement can be avoided by selection of the necessary posterior height of the hyperlordotic cage while still gaining sufficient lumbar lordosis.

How to avoid intraoperative complications of active paragangliomas?

Background

Paragangliomas (PGs) are very rare neuroendocrine tumors that can be found in unusual locations such as the spinal canal. Some PGs may be endocrinologically active, containing neurotransmitters such as noradrenaline, adrenaline, and serotonin. This can lead to unexpected neurotransmitter release during the removal of PGs, leading to a hypertensive crisis.

Case Description

We present two patients who underwent surgical removal of a secretory filum terminale PG.

Conclusion

If laboratory tests are suggestive of a secretory tumor, surgery should include anesthesiologic preparation similar to cases of pheochromocytoma.

Spinal cord tethering and syringomyelia after trauma: impact of age and surgical outcome

Posttraumatic spinal cord tethering and syringomyelia frequently lead to progressive neurological loss. Although several studies demonstrated favourable outcome following spinal cord detethering with/without shunting, additional research is required as no clear consensus exists over the ideal treatment strategy and knowledge about prognostic demographic determinants is currently limited. In this investigation, we retrospectively investigated 67 patients (56 men, 11 women) who were surgically treated and followed for symptomatic spinal cord tethering and syringomyelia from 2012 to 2022 at our center. Age (B-coefficient 0.396) and severity of trauma to the spinal cord (B-coefficient - 0.462) have been identified as independent predictors for the rate of development of symptomatic spinal cord tethering and syringomyelia (p < 0.001). Following untethering surgery including expansion duraplasty with/without shunting, 65.9% of patients demonstrated an improvement of neurological loss (p < 0.001) whereas 50.0% of patients displayed amelioration of spasticity and/or neuropathic pain (p < 0.001). Conclusively, active screening for symptomatic spinal cord tethering and syringomyelia, particularly in younger patients with severe spinal trauma, is crucial as surgical untethering with/without shunting is able to achieve favourable clinical outcomes. This knowledge may enable clinicians to tailor treatment strategies in spinal cord injury patients suffering from progressive neurological loss towards a more optimal and personalized patient care.

Multi-rod fixation in spinal neuroarthropathy: a novel surgical technique

Spinal cord injury (SCI) leads to compromised biomechanical stability due to impaired neuroprotection. This may trigger deformity and destruction of multiple segments of the spine which is known as spinal neuroarthropathy (SNA) or Charcot arthropathy. Surgical treatment of SNA is highly demanding in terms of reconstruction, realignment, and stabilization. In particular, construct failure due to the combination of high shear forces and reduced bone mineral density in the lumbosacral transition zone is a frequent complication in SNA. Notably, up to 75% of SNA patients need multiple revisions within the first year after surgery in order to achieve successful bony fusion. The purpose of this technical report is to present a novel surgical approach with higher overall construct stability to efficiently treat SNA and avoiding repetitive revisions. The new technique of triple rod stabilisation of the lumbosacral transition zone in combination with the introduction of tricortical laminovertebral (TLV) screws is demonstrated in three patients with complete SCI of the thoracic spinal cord. After surgery all patients reported an improvement of the Spinal Cord Independence Measure III (SCIM III) and none of the reported cases showed construct failure within an at least 9 months follow up period. Although TLV screws violate the integrity of the spinal canal, there were no complications with regard to cerebral spinal fluid fistulas and/or arachnopathies so far. The new concept of triple rod stabilization in combination with TLV screws provides improved construct stability in patients with SNA and thus could help to reduce revision and complications rates and improve patient outcome in this disabling degenerative disease.

A cervical solitary fibrous tumor with intramedullary invasion

Solitary fibrous tumor is a tumor originating from the mesenchymal cells, which occurrence in the central nervous system is extremely rare and was described in few patients as to yet. We report on a 53-years old male patient presenting with right upper limb radicular pain and ipsilateral limbs paresis, who was diagnosed with a cervical spinal lesion which, after surgical resection, resulted to be a solitary fibrous tumor (SFT). We discuss imaging, clinical and histopathological findings to allow considering this tumor early in the differential diagnosis.

Pros of the contralateral (over-the-top) approach to intra/extraforaminal lumbar disc herniations at the L5-S1 level

Background:

Minimally invasive approaches to intra/extraforaminal lumbar disc herniations offer the benefit of less bone removal and reduced nerve root manipulation at the L5-S1 level. Moreover, the potential to better preserve stability.

Methods:

Here, we summarized the efficacy of the contralateral approach to intraforaminal/extraforaminal lumbar disc herniations particularly focusing on the L5-S1 level. Variables studied included the level of these disc herniations, their locations within the foramina, and the anatomy of the facet joints.

Results:

A major “pro” for the contralateral interlaminar procedure at the L5-S1 level is that it does not require facet joint removal, or with a spondylotic facet, <30% joint excision, to directly visualize the intraforaminal/ extraforaminal nerve root. It, therefore, reduces the risk of creating iatrogenic instability, while offering a higher certitude of adequate nerve root visualization, decompression, and safer disc removal.

Conclusion:

The contralateral interlaminar approach is more suitable for all types of intra/extraforaminal disc herniations at the L5/S1 level. The most specific benefit of this approach is its avoidance of disruption/significant removal (i.e., <30%) of the facet joint to adequately expose the foraminal L5 nerve root, and more safely remove the intra/extraforaminal disc herniation.

Is transcranial magnetic stimulation as treatment for neuropathic pain in patients with spinal cord injury efficient? A systematic review

BACKGROUND AND PURPOSE

Neuropathic pain is a clinically relevant complication in individuals with spinal cord injury (SCI). Pharmacological pain treatment is often insufficient and leads to undesirable side effects. Thus, alternative therapeutic approaches such as repetitive transcranial magnetic stimulation (rTMS) are of critical importance. We aimed to evaluate the effectiveness of rTMS in neuropathic pain secondary to SCI.

METHODS

We conducted a systematic review using the PubMed/MEDLINE, EMBASE, and PsycInfo (via OVID) database up April 2021. Only randomized controlled trials were included. Results regarding the pain intensity scores were pooled using a random-effects model.

RESULTS

The search identified a total of 203 potential articles. Of these, eight randomized controlled trials (RCTs) met the eligibility criteria for qualitative synthesis providing the total data of 141 patients. All studies applied high-frequency rTMS. In seven studies, rTMS was applied over the motor cortex, and in one study over the left dorsolateral prefrontal cortex. Five studies reported a significant improvement in baseline pain scores after treatment, and three studies found a significant difference between sham vs. non-sham stimulation at any time. Six RCTs were included in the quantitative synthesis and showed a significant overall reduction of pain intensity in the rTMS groups compared with the sham groups (mean difference - 0.81, 95%CI - 1.45 to - 0.17).

CONCLUSIONS

Our findings indicate that high-frequency rTMS of the primary motor cortex and left dorsolateral prefrontal cortex might be promising stimulation targets for neuropathic pain in SCI.

SMART Syndrome (Stroke-like migraine attacks after radiation therapy): When to suspect it?

Background:

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a benign complication of brain radiation therapy, which presents circa a decade after radiation treatment. Symptoms are stroke-like deficits, epileptic seizures, and migraine. Cranial magnetic resonance imaging is characteristic for alterations in the form of unilateral cortical hyperintensities and gyriform enhancement, most prominent in the parieto-occipital regions. Prompt diagnosis is essential to avoid unnecessary investigations (e.g., brain biopsy and angiography).

Case Description:

We describe a 51-year-old female patient treated initially with cranial irradiation for a left-sided occipital metastatic lung adenocarcinoma. Five years later, she presented with migraine headache, aphasia, and a right sided hemiparesis.

Conclusion:

The triad of migraine, seizure, and hemiparesis within the context of a prior brain radiotherapy should promptly raise the suspicion of SMART syndrome. Prompt diagnosis is essential to avoid unnecessary invasive investigations.

Fragile-X-Associated Tremor/Ataxia Syndrome or Alcohol-Induced Cerebellar Degeneration? A Case Report

Fragile-X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder that manifests with intention tremor, progressive gait ataxia, and cognitive impairment. The disease is genetically characterized by a premutation of the FMR1gene on the X-chromosome manifesting with a CGG triplet expansion between 55 and 200. Given the phenotypical variety of this disease, diagnosis is frequently delayed. We present and discuss a male patient whose diagnosis of FXTAS was delayed due to his concomitant alcohol abuse.

Intrathecal pump catheter-tip granuloma recurrence with associated myelomalacia - How safe is intrathecal analgesic infusion therapy? A case report

Background:

A serious complication of intrathecal (IT) infusion therapy for pain management is catheter-tip-associated granuloma. Catheter-tip granulomas can lead to permanent severe neurological sequelae if not promptly detected.

Case Description:

We report a patient with a recurrence of a catheter-tip granuloma causing a high-grade paresis of the lower extremities and we review briefly the literature.

Conclusion:

Patients with IT pump therapy presenting new neurological findings need prompt imaging of the spinal axis to rule out a catheter-tip granuloma. In case of catheter-tip granuloma, early surgical decompression is important.

X-linked hypophosphatemic rickets and sagittal craniosynostosis: three patients requiring operative cranial expansion: case series and literature review

PURPOSE

A defect in a phosphate-regulating gene leads to the most common form of rickets: X-linked hypophosphatemic rickets (XLH) or vitamin D-resistant rickets (VDDR). XLH has been associated with craniosynostosis, the sagittal suture being the most commonly involved.

METHODS

We present three patients with rickets and symptomatic sagittal suture craniosynostosis all of whom presented late (>2 years of age). Two had a severe phenotype and papilledema, while the third presented with an osseous bulging near the anterior fontanel and experienced chronic headaches.

RESULTS

All underwent successful cranial vault expansion.

CONCLUSIONS

Rachitic patients with scaphocephaly should be screened for craniosynostosis.