Kern Singh: Spine essentials handbook: a bulleted review of anatomy, evaluation, imaging, tests, and procedures

How I do it? Transforaminal endoscopic decompression of intraspinal facet cyst Abstract Background Transforaminal endoscopic surgery provides equivalent results to open surgery with added advantages of feasibility under local anesthesia, no injury to posterior elements, preservation of the ligamentum flavum, ease of revision surgery, and cost-effectiveness. The technique of transforaminal endoscopic excision of cysts of facet or zygapophyseal joints is scarcely described in literature. Methods The transforaminal endoscopy is applicable to cyst lying in the extraforaminal, foraminal, and intraspinal regions. The “mobile” outside-in technique combined with osteotomy of the tip of the superior articular process facilitates intraspinal access for complete decompression. Conclusion Transforaminal endoscopic removal of the facet cyst is a viable alternative to traditional open surgery with added advantages of a minimal access procedure.

Radiosurgery treatment is associated with improved facial nerve preservation versus repeat resection in recurrent vestibular schwannomas

A modified park bench position: the “Dormeuse” position Abstract Background Because of the restricted volume of the cisternal space, proper patient positioning on the operating table is of utmost importance during surgery by retrosigmoid approaches. Three positions are commonly used: supine, with the head rotated to the side contralateral to the lesion; the semi-sitting position; and the park bench position. Each position has advantages and disadvantages, and the surgeon should choose the one best suited to the individual patient and the pathology to be treated. Methods We describe a modified park bench position that we call the Dormeuse position. Conclusion The Dormeuse position guarantees decrease in the posterior fossa pressure and allows optimal neural and vascular manipulation and control of any aspect of the cerebellopontine angle.

Efficacy of cyst-cisternal shunt for refractory cyst regrowth of cystic vestibular schwannomas Abstract Vestibular schwannomas (VSs) are generally benign and slow-growing tumors, and microsurgical resection is the commonly recommended treatment. Some reports suggested that inserting a cystoperitoneal shunt was effective for treatment of cystic VSs; however, there was no report of a cyst-cisternal shunt which diverts cyst fluid into cistern. We report a case of cystic VS with repeated cyst regrowth within weeks after repeated surgeries. We prevented further recurrence using cyst-cisternal shunt. This technique may be a new treatment option for refractory cyst regrowth of cystic VSs.

Late recovery of responsiveness after intra-thecal baclofen pump implantation and the role of diffuse pain and severe spasticity: a case report Abstract Patients with a prolonged disorder of consciousness (DoC) may present with severe spasticity and diffuse pain, which might impair motor output, thus preventing any possible behavioral responsiveness. A 26-year-old man affected by frontoparietal hemorrhage was operated by hematoma evacuation and decompressive craniectomy; coma persisted for 1 month; cranioplasty and ventriculo-peritoneal shunting was performed after 4 months. At admission in rehabilitation, he was diagnosed as vegetative state/unresponsive wakefulness syndrome (VS/UWS). The implantation of intrathecal baclofen (ITB) pump (Medtronic SynchroMed™ II), 14 months after, (60 μg/daily), dramatically improved behavioral responsiveness according to Coma Recovery Scale-Revised (CRS-R) from 6 to 12 (1 month after ITB). Nociception Coma Scale-Revised (NCS-R) also changed from 4 to 8 at the same time points. This case report may be an example of covert cognition that should have been diagnosed as a functional locked-in syndrome or motor-cognitive dissociation, rather than as VS/UWS.

Adult outcome after neurosurgical treatment of brain tumours in the first year of life: long-term follow-up of a single consecutive institutional series of 34 patients Abstract Background Long-term results for adult patients who underwent surgery for paediatric brain tumours in the first year of life have not been reported. Methods We performed a retrospective study on surgical morbidity, mortality rate, academic achievement and/or work participation in patients who underwent primary tumour resection for a brain tumour as infants in the period from 1973 to 1998. Gross motor function and activities of daily life were scored according to the Barthel Index. Findings Thirty-four consecutive children were included. No patient was lost to follow-up. Twenty-two children (65%) underwent gross total resection (GTR), 10 had subtotal resections (STR) and 2 had only partial resection during primary surgery. Nine children were additionally surgically treated for hydrocephalus (HC), many of them with repeat operations for shunt malfunction during follow-up. Three children died within 30 days following GTR of highly vascular tumours. Seventeen (50%) of the infants had high-grade tumours with 1-month, 1-year and 20-year survival figures of 88, 30 and 30%. The corresponding figures for 17 patients treated for low-grade tumours were 94%, 88% and 88%, respectively. Seventeen patients (50%) are still alive as adult long-term survivors at median age of 29 years (range 20 to 43 years). Three died after 29, 30 and 41 years, respectively. At the latest follow-up, 16 out of 17 long-term survivors have a Barthel Index (BI) of 100, while the remaining one has a BI of 40. Two long-term survivors of a high-grade tumour treated 30 and 35 years ago are severely handicapped and have no working capacity. The 15 long-term survivors after treatment for a low-grade tumour are all in daily activity as students (4), in part-time work (3) or full-time work (8). Conclusion A brain tumour occurring in the first year of life is a serious threat to the patient and the family, particularly in case of high-grade tumours. In our small cohort, the results from long-term survivors of high-grade tumour group are depressing and confirm the deleterious effect of radiotherapy given to infants decades ago. The infants with low-grade tumours who could be treated with surgical resection without any adjuvant therapy show a good clinical outcome as adults. For parents of these latter patients, the results are far better than feared in advance.

Genomic profile of a primary squamous cell carcinoma arising from malignant transformation of a pineal epidermoid cyst Abstract Malignant transformation of intracranial epidermoid cysts is a rare occurrence. We present the second case of such an event occurring in the pineal region and the first case sent for detailed genomic profiling. MRI demonstrated two lesions: a cyst in a quadrigeminal cistern with restricted diffusion on DWI-weighted images and an adjacent, peripherally enhancing tumor with cerebellar infiltration. Both the lesions were completely resected with a small residual of the epidermoid cyst. The final pathology of both lesions was consistent with epidermoid cyst and squamous cell carcinoma (SCC), respectively. The tumor specimen was sent for comprehensive genomic profiling which revealed stable microsatellite status and loss of CDKN2A/B, MTAP (exons 2–8), and PTEN (exons 6–9). Although reports of primary SCC originating from the epidermoid cyst have been previously described, this is the first description of the genomic profile of such a tumor.

Management of perineural (Tarlov) cysts: a population-based cohort study and algorithm for the selection of surgical candidates Abstract Objective Perineural cysts, also known as Tarlov cysts, are cerebrospinal fluid-filled growths that develop at the intersection of a dorsal root ganglion and posterior nerve root. They are typically an asymptomatic and incidental finding during routine spine imaging. For symptomatic perineural cysts, there is little evidence on which treatment is most effective or when it is indicated. The aim of this study was to review our experience from a population-based cohort of patients with symptomatic perineural cysts and to propose an algorithm that could be used in the selection of surgical candidates. Methods A retrospective review was conducted of all adult (≥ 15 years) patients with symptomatic perineural cysts who were referred to Karolinska University Hospital between 2002 and 2018. Results Thirty-nine patients were included. The most common symptom was sciatica (n = 22). Cyst aspiration was performed in 28 patients, 24 of whom showed clinical improvement and were offered surgery. Microsurgical cyst fenestration was performed in 17 patients, 16 of whom showed clinical improvement at long-term follow-up. There were no surgical complications. Ten of the patients who were offered surgery chose to be treated conservatively instead, four of whom showed progression of symptoms at long-term follow-up. Conclusions Microsurgical cyst fenestration seems to be a safe and effective option for symptomatic relief in patients with perineural cysts. Based on the results from our series and those of others, we propose an algorithm for the selection of surgical candidates.

Indication and technical implementation of the intraoperative neurophysiological monitoring during spine surgeries—a transnational survey in the German-speaking countries Abstract Background Intraoperative neurophysiological monitoring is widely used in spine surgery (sIONM). But guidelines are lacking and its use is mainly driven by individual surgeons’ preferences and medicolegal advisements. To gain an overview over the current status of sIONM implementation, we conducted a transnational survey in the German-speaking countries. Methods We developed a Web interface-based survey assessing prevalence, indication, technical implementation, and general satisfaction regarding sIONM in German, Austrian, and Swiss spine centers. The electronic survey was performed between November 2017 and April 2018, including both neurosurgical and orthopedic spine centers. Results A total of 463 German, 60 Austrian, and 52 Swiss spine centers were contacted with participation rates of 64.1% (Germany), 68.3% (Austria), and 55.8% (Switzerland). Some 75.9% participating neurosurgical spine centers and only 14.7% of the orthopedic spine centers applied sIONM. Motor- and somatosensory-evoked potentials (93.7% and 94.3%, respectively) were the most widely available modalities, followed by direct wave (D wave; 66.5%). Whereas sIONM utilization was low in spine surgeries for degenerative, traumatic, and extradural tumor diseases, it was high for scoliosis and intradural tumor surgeries. Overall, the general satisfaction within the institutional setting regarding technical skills, staff, performance, and reliability of sIONM was rated as “high” by more than three-quarters of the centers. However, shortage of skilled staff was claimed to be a negative factor by 41.1% of the centers and reimbursement was considered to be insufficient by 83.5%. Conclusions sIONM availability was high in neurosurgical but low in orthopedic spine centers. Main modalities were motor/somatosensory-evoked potentials and main indications were scoliosis and intradural spinal tumor surgeries. A more frequent sIONM use, however, was mainly limited by the shortage of skilled staff and restricted reimbursement.