Background and importance: Paragangliomas are neuroendocrine tumors that occur most often within the adrenal glands. The most frequent extra-adrenal locations include the carotid body and the jugular bulb. Filum terminale paragangliomas are extremely rare, with just 33 cases reported to date. Imagistic appearance is similar with other types of intradural extramedullary tumors such as ependymomas and schwannomas. Histopathological examination is the only method of establishing a definitive diagnosis. They are classified as grade I WHO tumors with favorable prognosis in the case of total resection. Clinical presentation: A 46-year-old woman without any relevant medical history was admitted to our Neurosurgical Department, complaining of low back pain with bilateral sciatica. She presented no neurological deficits and routine blood tests, as well as heart rate and blood pressure, were within normal ranges. Lumbar spine MRI with gadolinium enhancement revealed an intradural tumor with irregular, well defined margins and intense homogeneous enhancement, located at the level of the L3 vertebra. It presented an unenhancing intradural cystic lesion that extended cranially up to the level of the L1 vertebra. The tumor and associated cyst were completely resected through L2-L4 laminectomy. The tumor-cyst complex was attached, yet nonadherent to the conus medullaris and nerve roots, which allowed safe total removal. Histopathological examination was suggestive for paraganglioma, a diagnosis confirmed by immunohistochemistry that classified it as moderately differentiated, non-secreting type. Serum metanephrines subsequently determined were within normal ranges. Also, additional imagistic tests consisting of cervical and abdominal ultrasound and contrast enhanced CT scans did not detect any additional tumors. Postoperatively, the patient was neurologically intact, with complete remission of presenting symptoms at 3 months follow-up. Conclusion: Filum terminale paraganglioma is a rare diagnosis which is frequently overlooked. However, gross total resection, a common goal for all spinal tumors, can be curative in these particular cases.

Abstract:Background: Degenerative spinal disease surgery is frequently performed in most neurosurgical departments. Unplanned 30-day readmissions represent a significant economic burden and have been used in several studies as a tool to evaluate quality of patient care. Objective: To review 30-day unplanned readmission rates after degenerative spinal disease surgery in our department, in order to identify their causes and determine strategies aimed at decreasing their frequency. Methods: A retrospective analysis was performed on all patients operated in our department for spinal stenosis or disc herniation over a 3 year period (January 2014 -December 2016), evaluating the rate and causes of unplanned readmission in the first month after discharge. Complications were divided in medical and surgical. Results: Out of the 1106 patients included, 33 (2,98%) presented a 30-day unplanned readmission. The percentage was higher after disc herniation surgery (3,40%), compared to spinal stenosis (1,92%). Pain management was the most common medical cause for readmission (45,45%), while in the surgical group, CSF leaks were the most frequent complication (18,18%). Conclusions: The rate of 30-day readmissions was low in our series but, even so, they associate significant costs. They could be avoided by applying correct and aseptic surgical technique, proper availability of dural sealing agents and superior patient medical education.

Background and importance:Butterfly vertebra is an uncommon congenital spinal anomaly, which can be easily mistaken for vertebral fracture, infection or tumor. Clinical presentation: We report the case of a 20-year-old male patient with a 3-year history of intermittent mid-thoracic spinal pain. Local examination showed a mild thoracic kyphoscoliosis. Neurological examination was normal. Computer tomography revealed the presence of a T6 butterfly vertebra associated with morphological anomalies in adjacent vertebral bodies and T6-T9 Schmorl's nodes. MRI scan confirmed the diagnosis and additionally showed a mild spinal stenosis caused by apparent posterior epidural fat hypertrophy. The patient was treated with painkillers and physical therapy. Conclusion: Butterfly vertebra is a benign condition. Once diagnosed, additional diagnostic procedures are not necessary. Neurosurgeons must be aware of this congenital anomaly that should not be confused with a vertebral fracture.

Background and importance: “Fish vertebra” is an uncommon anomaly of vertebral body shape, consisting of central depression of the superior and inferior vertebral surfaces. It has been associated with various conditions: osteoporosis, osteomalacia, hyperparathyroidism, Paget disease, sickle cell disease, multiple myeloma and systemic lupus erythematosus. Clinical presentation: A 29-year-old male patient, previously treated for ankylosing spondylitis (with NSAIDs and TNFα inhibitor), without any clinical improvement, was admitted to our Neurosurgical Department. He complained of difficult gait, possible only with the aid of a cane, low back pain and bilateral hip pain, but without leg pain. He denied any history of recent trauma. Neurological examination was normal. Plain thoracic and lumbar spine X-rays revealed multilevel “fish vertebrae”. Lumbar spine MRI and contrast thoraco-abdominal CT scan showed fractures of multiple structures: left L4 pedicle, right L4 lamina and pars interarticularis, right II-VII costal arches, left I-V costal arches and bilateral sacral alae. We performed extensive laboratory tests that detected low seric phosphorous and PTH levels, with increased alkaline phosphatase, indicating a possible endocrinological cause for this condition. Subsequently, we decided to transfer the patient to an Endocrinological Department. A diagnosis of hypophosphatemic osteomalacia was established and increased FGF23 levels, later determined, suggested it was tumor-induced osteomalacia. Whole-body MRI was unable to locate the tumor, but Gallium-68 DOTATATE PET/CT revealed a small (15 mm in diameter), hyperfixating mass in the head of the right femur. The patient was treated with oral calcitriol and phosphate, with alleviation of symptoms. Surgical excision of the tumor was recommended, but the patient decided to postopone the operation. Conclusion: Modern medical imaging and biochemical testing have made the leap from merely observing vertebral biconcavities to diagnosing their cause and, consequently, the possibility to adequately treat uncommon causes of “fish vertebra”, such as neuroendocrine tumor-induced osteomalacia.

Background: Neural decompression for lumbar spinal stenosis (LSS) can be performed, besides conventional lumbar laminectomy, by many other surgical techniques. Objective: The goal of this study is to analyze the results of laminectomy versus unilateral fenestration and foraminotomy with bilateral neural decompression in LSS patients. Methods: A number of 58 patients with lumbar spinal stenosis were divided into two groups: group A (no.=22) consists of patients that underwent a laminectomy procedure and group B (no.=36) of cases where unilateral fenestration with foraminotomy was used. Outcome was assessed at 1, 6 and 12 months postoperatively. Two parameters were evaluated: level of pain with the VAS (Visual Analogue Scale) score and the ODI (Oswestry Disability Index) scale for functional improvement. Results: The level of pain was reduced in both patient groups. Cases in group A maintained higher levels of back pain in the first postoperative month versus group B. Improvement was faster for those operated by unilateral approach. At 6 months and 1 year follow-ups, VAS values were very similar. All patients presented functional recovery evaluated with the ODI scale, that showed continuous improvement at 6 months and 1 year. Conclusions: Bilateral decompression by unilateral approach is an efficient method that represents the first option of treatment for patients with lateral lumbar spinal stenosis with unilateral or predominantly unilateral symptoms. For patients with severe central stenosis, classic laminectomy remains the first surgical choice.