Surgical Highways to the Craniovertebral Junction: Is It Time for a Reappraisal?

BACKGROUND: The craniovertebral junction (CVJ) can be affected by a variety of congenital or acquired anomalies. Because of its complexity, a careful evaluation of bones and ligamentous structures in all three planes is required. This can be achieved by studying the CVJ in terms of several anatomical and radiological lines that have been visualized to facilitate understanding of its surgical anatomy. In this study we aimed to review the state-of-the art craniometric CVJ lines and approaches. METHODS: In December 2016 a PubMed search was performed, including the search terms 'CVJ surgical approach/line', 'cervical approach', 'craniometric measurement', 'CVJ anatomy' and 'ventral/dorsal/far-lateral approach'. Anatomical and radiological lines and angles evaluated on traditional radiography, computed tomography (CT) scanning or magnetic resonance imaging (MRI) in the axial/sagittal/coronal views were included and described. RESULTS: Several measurements and radiological landmarks were included to evaluate the anatomy of the CVJ. They were fully described and categorized on the basis of the anatomical plan and the surgical or diagnostic purpose they are used for. CONCLUSION: Among the numerous radiological measurements described, it has been shown that McRae's line, Chamberlain's line, McGregor's line, the Redlund-Johnell method and Ranawat's line are the most widely used and reliable ones for evaluating skull base craniometry. Secondly, the hard palate line (HPL), nasoaxial line (NAxL) and palatine-inferior dental arch line (PIA) are used to preoperatively assess the ventral endonasal or transoral surgical approaches. Thirdly, the C7 slope has been demonstrated as a reliable predictor of occipitocervical and spinopelvic alignment in CVJ fusion.

Preliminary experience with a transcranial magnetic resonance-guided focused ultrasound surgery system integrated with a 1.5-T MRI unit in a series of patients with essential tremor and Parkinson's disease.

OBJECTIVE Transcranial magnetic resonance-guided focused ultrasound surgery (tcMRgFUS) is one of the emerging noninvasive technologies for the treatment of neurological disorders such as essential tremor (ET), idiopathic asymmetrical tremor-dominant Parkinson's disease (PD), and neuropathic pain. In this clinical series the authors present the preliminary results achieved with the world's first tcMRgFUS system integrated with a 1.5-T MRI unit. METHODS The authors describe the results of tcMRgFUS in a sample of patients with ET and with PD who underwent the procedure during the period from January 2015 to September 2017. A monolateral ventralis intermedius nucleus (VIM) thalamic ablation was performed in both ET and PD patients. In all the tcMRgFUS treatments, a 1.5-T MRI scanner was used for both planning and monitoring the procedure. RESULTS During the study period, a total of 26 patients underwent tcMRgFUS thalamic ablation for different movement disorders. Among these patients, 18 were diagnosed with ET and 4 were affected by PD. All patients with PD were treated using tcMRgFUS thalamic ablation and all completed the procedure. Among the 18 patients with ET, 13 successfully underwent tcMRgFUS, 4 aborted the procedure during ultrasound delivery, and 1 did not undergo the tcMRgFUS procedure after stereotactic frame placement. Two patients with ET were not included in the results because of the short follow-up duration at the time of this study. A monolateral VIM thalamic ablation in both ET and PD patients was performed. All the enrolled patients were evaluated before the treatment and 2 days after, with a clinical control of the treatment effectiveness using the graphic items of the Fahn-Tolosa-Marin tremor rating scale. A global reevaluation was performed 3 months (17/22 patients) and 6 months (11/22 patients) after the treatment; the reevaluation consisted of clinical questionnaires, neurological tests, and video recordings of the tests. All the ET and PD treated patients who completed the procedure showed an immediate amelioration of tremor severity, with no intra- or posttreatment severe permanent side effects. CONCLUSIONS Although this study reports on a small number of patients with a short follow-up duration, the tcMRgFUS procedure using a 1.5-T MRI unit resulted in a safe and effective treatment option for motor symptoms in patients with ET and PD. To the best of the authors' knowledge, this is the first clinical series in which thalamotomy was performed using tcMRgFUS integrated with a 1.5-T magnet.

Spinal Cord Stimulation: An Alternative Concept of Rehabilitation?

BACKGROUND: Chronic low back and leg pain is a disabling condition, affecting, in most cases, older patients with congenital or acquired spinal stenosis or patients with failed back surgery syndrome. Spinal cord stimulation has been introduced as an effective therapeutic option for those patients who have previously been operated without significant clinical benefits, or for all those patients who are ineligible for traditional surgery. METHODS: We report our experience with ten patients treated with spinal cord stimulation plus medication and physical therapy between November 2014 and September 2015. Inclusion criteria were: previous surgical treatments for lumbar stenosis and metameric instability and persistent or ingravescent disabling low back and leg pain, with a mean duration of symptoms of at least 18 months. A visual analog scale (VAS) was employed for back and leg pain, and the Oswestry Disability Index (ODI) score was determined, and findings were analyzed after 6 months. FINDINGS: No intra- or postoperative complication was recorded. The mean VAS score for back pain decreased from 7.5 to 2.9, while leg VAS decreased from 8.2 to 3.0. Analysis of ODI values showed evident improvement in daily life activities, ranging from a median value of 75.7% to 32.7 % after the stimulation. CONCLUSION: Spinal cord stimulation has a recognized impact on the pain and on the quality of life of patients with failed back surgery syndrome.

Restoring Neurological Physiology: The Innovative Role of High-Energy MR-Guided Focused Ultrasound (HIMRgFUS). Preliminary Data from a New Method of Lesioning Surgery.

BACKGROUND: Tremor is a disabling condition, common to several neurodegenerative diseases. Lesioning procedures and deep brain stimulation, respectively, of the ventralis intermedius nucleus for intentional tremor, and of the subthalamic nucleus for parkinsonian resting tremor, have been introduced in clinical practice for patients refractory to medical treatment. The combination of high-energy focused ultrasound (HIFUS) with sophisticated magnetic resonance (MR) instrumentation, together with accurate knowledge of the stereotactic brain coordinates, represents a revolution in neuromodulation. METHODS: At the Neurosurgical Clinic and the Radiology Department of the University of Palermo,, two patients affected by severe and refractory forms of intentional tremor were treated by MRI-guided FUS (MRgFUS) with a unique 1.5 T MR scanner prototype that uses FUS. This apparatus is the only one of its type in the world." FINDINGS: This is the first Italian experience, and the second in Europe, of treatment with MRI-gFUS for intentional tremor. But this is the very first experience in which a 1.5 T MRI apparatus was used. In both patients, the treatment completely abolished the tremor on the treated side, with results being excellent and stable after 7 and 5 months, respectively; no side effects were encountered. CONCLUSION: MRgFUS, recently introduced in clinical practice, and widely used at several clinical centers, has been shown to be a valid therapeutic alternative in the treatment of tremor in several neurodegenerative diseases. It is virtually safe, noninvasive, and very efficacious. We report this technique in which a 1.5 T MR scanner was used. Further investigations with long-term follow up and larger clinical series are needed.

Reconstruction of Vertebral Body After Radiofrequency Ablation and Augmentation in Dorsolumbar Metastatic Vertebral Fracture: Analysis of Clinical and Radiological Outcome in a Clinical Series of 18 Patients.

BACKGROUND: Painful spinal metastases usually occur in malignant neoplastic disease. Treatment for bone metastases has been largely conservative, and it includes the use of high doses of analgesics, radiotherapy, chemotherapy, hormone therapy, and bisphosphonates; however, results are sometimes transient and ineffective. In the presence of neurological involvement a surgical strategy should be considered. Recently, percutaneous procedures such as radiofrequency ablation, vertebroplasty, and kyphoplasty have been introduced as palliative techniques to treat painful vertebral metastases [3, 11, 25]. METHODS: In our study we combined the use of radiofrequency ablation with vertebroplasty in the treatment of dorsolumbar metastatic vertebral fractures in order to examine the relationship between restoration of the vertebral structure and decrease in pain. From January 2014 to March 2015 we retrospectively analyzed 18 patients with malignant vertebral lesions who underwent radiofrequency ablation with vertebroplasty followed by cementoplasty, with posterior transpedicle fixation on levels near the lesions. The parameters examined were: demographics, pain relief, and the distribution of polymethylmethacrylate (PMMA) determined by the mean Saliou filling score; all complications were recorded. FINDINGS: The mean age of the patients was 55.72 years (range 34-69); average operative time was 60.4 min (range, 51-72). The average pain index score (visual analog score; VAS) decreased significantly from 8.05 at baseline to 3.0 (p < 0.05) after 6 months. The Saliou filling score revealed a distribution of PMMA in the vertebral body that was satisfactory (12-18) in eight patients, mediocre (6-12) in seven patients, and inadequate (0-6) in the remaining three patients. In two vertebrae, minimal asymptomatic cement leakage occurred in the lateral recess without neurological damage. No pulmonary embolism and no visceral or neural damage was recorded. CONCLUSION: Radiofrequency ablation combined with vertebroplasty seems to achieve rapid and lasting improvement in clinical symptoms in patients with malignant vertebral lesions. There was wide diffusion of PMMA in the vertebral body, with a mean cement volume of 4.5 ml.

Percutaneous Pedicle-Lengthening Osteotomy in Minimal Invasive Spinal Surgery to Treat Degenerative Lumbar Spinal Stenosis: A Single-Center Preliminary Experience.

BACKGROUND: Lumbar spinal stenosis (LSS) is a narrowing of the spinal canal due to spinal degeneration, and its main clinical symptom is neurogenic claudication. Surgical treatment is pursued for patients who do not improve with conservative care. Patients with symptomatic LSS who also have significant medical comorbidities, although clearly in need of intervention, are unattractive candidates for traditional open lumbar decompressive procedures. Thus it is important to explore minimally invasive surgical techniques to treat select patients with LSS. METHODS: This retrospective case series evaluated the clinical and radiographic outcomes of a new minimally invasive procedure to treat LSS: pedicle-lengthening osteotomy using the ALTUM system ((Innovative Surgical Designs, Inc., Bloomington, Indiana, United States). Peri- and postoperative demographic and radiographic data were collected from a clinical series of seven patients with moderate LSS who were > 60 years of age. Clinical outcome was evaluated using visual analog scale (VAS) scores and the spinal canal area on computed tomography scans. RESULTS: Twelve months after the procedure, scoring revealed a median improvement of 3.7 on the VAS for the back and 6.3 on the VAS for the leg, compared with the preoperative baseline (p < 0.05). The postoperative central area of the lumbar canal was significantly increased, by 0.39 cm2; the right and left neural foramina were enlarged by 0.29 cm2 and 0.47 cm2, respectively (p < 0.05). CONCLUSIONS: In this preliminary study, the ALTUM system showed a good clinical and radiologic outcome 1 year after surgery. In an older or high-risk population, a short minimally invasive procedure may be beneficial for treating LSS.

Never say never again: A bone graft infection due to a hornet sting, thirty-nine years after cranioplasty.

BACKGROUND: Cranioplasty (CP) is a widespread surgical procedure aimed to restore skull integrity and physiological cerebral hemodynamics, to improve neurological functions and to protect the underlying brain after a life-saving decompressive craniectomy (DC). Nevertheless, CP is still burdened by surgical complications, among which early or late graft infections are the most common outcome-threatening ones. CASE DESCRIPTION: We report the case of 48-year-old man admitted to our neurosurgical unit because of a painful right frontal swelling and 1-week purulent discharge from a cutaneous fistula. He had been undergone frontal CP because of severe traumatic brain injury (TBI) when he was 9-year-old. Since then, his medical history has been being unremarkable without any surgical or infective complication of the graft for 39 years, until he was accidentally stung by a hornet in the frontal region. After the CT scan and laboratory findings had evidenced a probable infection of the graft, the patient was treated by vancomycin and cefepime before he underwent surgical revision of its former CP, with the removal of the graft and the debridement of the surgical field. Subsequent bacteriological tests revealed Staphylococcus aureus as causal agent of that infection. CONCLUSION: This case illustrates an anecdotal example of very late CP infection, due to an unpredictable accident. Due to lack of consensus on risk factors and on conservative or surgical strategy in case of graft infection, we aimed to share our surgical experience.

A thoracic vertebral localization of a metastasized cutaneous Merkel cell carcinoma: Case report and review of literature.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin tumor, which may be related to sun exposure. It can metastasize to lungs, liver and bone, leading to severe morbidity and mortality. Vertebral metastases from MCC are rare. The authors report the tenth case in the literature, a 59-year-old patient with MCC, which was primarily localized in the scalp, and later provoked distant metastasis to the thoracic spinal column. CASE DESCRIPTION: A 59-year-old woman was admitted at our Unit of Neurosurgery with a 4-month history of progressive and severe dorsal back pain, without neurological signs. The patient had been surgically treated for a recidivated MCC in the occipital region in 2007, 2011, and 2013. (In 2013, the surgical treatment also included lateral cervical lymph node dissection). Chemotherapy and radiotherapy had come after the treatments. Magnetic resonance imaging (MRI) of the dorsal spine showed metastatic vertebral involvement with cord impingement of the T7-T8 levels. A total body CT scan revealed lungs and liver metastases, besides vertebral district. After a multidisciplinary consult a palliative surgery was decided and a posterior dorsal approach was employed: Radiofrequency (RF) thermoablation was followed by the injection of cement of T7 and T8 and transpedicle fixation T5-T9. The postoperative course was uneventful and followed by a further adjuvant therapy. CONCLUSION: Spinal metastases from MCC are described in literature only exceptionally. The clinical course is presented, along with a review of literature.

Surgical nuances on the treatment of giant dumbbell cervical spine schwannomas: description of a challenging case and review of the literature.

We report a case of a giant intra and extradural cervical schwannoma in a patient affected by a severe myelo-radiculopathy. Clinical features, diagnosis and the issues concerning the surgical management of this benign tumor are discussed. We also review similar cases previously reported in the literature. A 50-year old caucasian woman was complaining of a 1 year of neck pain and worsening motor impairment in all four limbs causing the inability to walk. Neuroradiological assessment revealed a suspected schwannoma involving the nerve roots from C3 to C5, compressing and deviating the spinal cord. The vertebral artery was also encased within the lesion, but still patent. A posterior cervical laminectomy with a microsurgical extradural resection of the lesion was performed. Moreover, an accurate dissection of the lesion from the vertebral artery and the resection of the intraspinal component was achieved. Vertebral fixation with screws on the lateral masses of C3, C5 and C6 and a hook on C1 was performed. The procedure was secured using electroneurophysiological monitoring. A progressive improvement of the motor functions was achieved. A cervical post-contrast MRI revealed optimal medullary decompression and a gross-total resection of the lesion. Schwannomas are benign, slowly growing lesions which may cause serious neurological deficit. Early diagnosis is necessary and it maybe aided by imaging studies such as MRI or CT. The accepted treatment for these tumors is surgical resection and, when indicated, vertebral fixation.

Delayed chronic intracranial subdural hematoma complicating resection of a tanycytic thoracic ependymoma.

BACKGROUND: To demonstrate that the diagnosis of an intracranial subdural hematoma should be considered for patients presenting with acute or delayed symptoms of intracranial pathology following resection of a spinal tumor. CASE DESCRIPTION: We present a case of a 57-year-old woman found to have a chronic subdural hematoma 1 month following resection of a thoracic extramedullary ependymoma. Evacuation of the hematoma through a burr hole relieved the presenting symptoms and signs. Resolution of the hematoma was confirmed with a computed tomography (CT) scan. CONCLUSION: Headache and other symptoms not referable to spinal pathology should be regarded as a warning sign of an intracranial subdural hematoma, and a CT scan of the head should be obtained. The mechanism of the development of the hematoma may be related to the leakage of cerebrospinal fluid with subsequent intracranial hypotension leading to an expanding subdural space and hemorrhage.

[Non-invasive trans-cranial magnetic resonance imaging-guided focused ultrasounds surgery to treat neurologic disorders]. / Terapia chirurgica trans-cranica non invasiva mediante ultrasuoni focalizzati guidati da risonanza magnetica per il trattamento di disordini neurologici.

In past years non-invasive clinical applications of magnetic resonance-guided focused ultrasound for the treatment of neurological disorders have been hampered by technical limitations that today have been finally overcome. In 2015, for the first time in the world, the very first treatments have been performed in Italy by the use of an affordable 1.5T magnetic resonance unit. The clinical results obtained to date and all the future possible applications are very promising and pave the way towards safe and effective treatment options once unthinkable.

A Strange Case of Downward Displacement of a Deep Brain Stimulation Electrode 10 Years Following Implantation: The Gliding Movement of Snakes Theory.

BACKGROUND: Despite the best efforts to ensure stereotactic precision, deep brain stimulation (DBS) electrodes can wander from their intended position after implantation. We report a case of downward electrode migration 10 years following successful implantation in a patient with Parkinson disease. METHODS: A 53-year-old man with Parkinson disease underwent bilateral implantation of DBS electrodes connected to a subclavicular 2-channel pulse generator. The generator was replaced 7 years later, and a computed tomography (CT) scan confirmed the correct position of both leads. The patient developed a gradual worsening affecting his right side 3 years later, 10 years after the original implantation. A CT scan revealed displacement of the left electrode inferiorly into the pons. The new CT scans and the CT scans obtained immediately after the implantation were merged within a stereotactic planning workstation (Brainlab). RESULTS: Comparing the CT scans, the distal end of the electrode was in the same position, the proximal tip being significantly more inferior. The size and configuration of the coiled portions of the electrode had not changed. At implantation, the length was 27.7 cm; after 10 years, the length was 30.6 cm. CONCLUSIONS: These data suggests that the electrode had been stretched into its new position rather than pushed. Clinicians evaluating patients with a delayed worsening should be aware of this rare event.