First Human In Vivo Neuroelectrophysiology Recordings of Uncrossed Dentatothalamocortical White-Matter Connections: On the Fast Tract.

OBJECTIVES: We aim to demonstrate intraoperative recording of cerebellar to cortical pathways that have not been previously recorded in humans, though imaged. METHODS: We report 2 cases with intraoperative neurophysiologic mapping of cerebellocortical tracts. Direct electrical stimulation of subcortical cerebellum along with recordings of cortical evoked potential and motor muscle recordings was performed during surgery. MR tractography data from healthy participants were used to further illustrate the pathways. RESULTS: Neurophysiologic recordings showed large waveforms of evoked potentials in bilateral electrodes over premotor/motor cortices on stimulation of the dentate nucleus. EMG recordings showed responses in face and neck muscles on stimulation of the dentate nucleus at the motor threshold. We thus demonstrated first-in-human in vivo neurophysiologic evidence of cerebellum to cortex responses through an uncrossed dentatothalamocortical tract to the motor/premotor cortices. DISCUSSION: This technique provides a methodology for the direct mapping of the cerebellum and cerebello-cerebral connections. We hypothesize a direct structural connection from the dentate nucleus to the premotor and motor cortices, as well as to ipsilateral hemibody muscles, acting as a fast route of cerebellar output and back up for immediate motor responses. This will further help explain the modulatory effects of the cerebellum on motor, language, and cognitive functions.

Intraoperative mapping of pre-central motor cortex and subcortex: a proposal for supplemental cortical and novel subcortical maps to Penfield's motor homunculus.

Penfield's motor homunculus describes a caricaturised yet useful representation of the map of various body parts on the pre-central cortex. We propose a supplemental map of the clinically represented areas of human body in pre-central cortex and a novel subcortical corticospinal tract map. We believe this knowledge is essential for safe surgery in patients with eloquent brain lesions. A single-institution retrospective cohort study of patients who underwent craniotomy for motor eloquent lesions with intraoperative motor neuromonitoring (cortical and subcortical) between 2015 and 2020 was performed. All positive cortical and subcortical stimulation points were taken into account and cartographic maps were produced to demonstrate cortical and subcortical areas of motor representation and their configuration. A literature review in PubMed was performed. One hundred and eighty consecutive patients (58.4% male, 41.6% female) were included in the study with 81.6% asleep and 18.4% awake craniotomies for motor eloquent lesions (gliomas 80.7%, metastases 13.8%) with intraoperative cortical and subcortical motor mapping. Based on the data, we propose a supplemental clinical cortical and a novel subcortical motor map to the original Penfield's motor homunculus, including demonstration of localisation of intercostal muscles both in the cortex and subcortex which has not been previously described. The supplementary clinical cortical and novel subcortical motor maps of the homunculus presented here have been derived from a large cohort of patients undergoing direct cortical and subcortical brain mapping. The information will have direct relevance for improving the safety and outcome of patients undergoing resection of motor eloquent brain lesions.

Electromagnetic Navigation Systems and Intraoperative Neuromonitoring: Reliability and Feasibility Study.

BACKGROUND: A recent influx of intraoperative technology is being used in neurosurgery, but few reports investigate the accuracy and safety of these technologies when used simultaneously. OBJECTIVE: To assess the ability to use an electromagnetic navigation system alongside multimodal intraoperative neurophysiological monitoring (IONM). METHODS: Single-institution prospective cohort study of patients requiring craniotomy for brain tumor resection operated using an electromagnetic navigation system (AxiEM, Medtronic®). motor evoked potentials, somatosensory evoked potentials (SSEPs), electroencephalography, and electromyography were recorded and analyzed with AxiEM on (with/without filters) and off. The neurological outcomes of the patients were recorded. RESULTS: A total of 15 patients were included (8 males/7 females, mean age 52.13 yr). Even though the raw acquisition is affected by the electromagnetic field (particularly SSEPs), no significant difference was detected in the morphology, amplitude, and latency of the different monitoring modalities (AxiEM off vs on) after the appropriate software filter application. Adjustments to the frequency of SSEP stimulation and number of averages, and reductions to the low-pass filters were applied. Notch filters were used appropriately and changes to the physical setup of the IONM and electromagnetic navigation system equipment reduced noise. Postoperatively, none of the patients developed new focal deficits; 7 patients showed improvement in their motor deficit (4 recovered fully). CONCLUSION: The information provided by the IONM in intracranial neurosurgery patients whilst also using electromagnetic navigation systems is reliable for monitoring, mapping, and detecting intraoperative complications, provided that the appropriate software filters and tools are applied.

Pre- and Intraoperative Mapping for Tumors in the Primary Motor Cortex: Decision-Making Process in Surgical Resection.

BACKGROUND: Lesions within the primary motor cortex (M1) and the corticospinal tract (CST) represent a significant surgical challenge with a delicate functional trade-off that should be integrated in the overall patient-centered treatment plan. METHODS: Patients with lesions within the M1 and CST with preoperative cortical and subcortical mapping (navigated transcranial magnetic stimulation [nTMS] and tractography), intraoperative mapping, and intraoperative provisional histologic information (smear with and without 5-aminolevulinic acid [5-ALA]) were included. This independently acquired information was integrated in a decision-making process model to determine the intraoperative extent of resection. RESULTS: A total of 10 patients (6 patients with metastatic precentral tumor; 1 patient with grade III and 2 patients with grade IV gliomas; 1 patient with precentral cavernoma) were included in the study. Most of the patients (60%) had a preoperative motor deficit. The nTMS documented M1 invasion in all cases, and in eight patients, the lesions were embedded within the CST. Overall, 70% of patients underwent gross total resection; 20% of patients underwent near-total resection of the lesions. In only one patient was no surgical resection possible after both preoperative and intraoperative mapping. Overall, 70% of patients remained stable postoperatively, and previous motor weakness improved in 20%. CONCLUSION: The independently acquired anatomical (anatomical MRI) and functional (nTMS and tractography) tests in patients with CST lesions provide a useful guide for resection. The inclusion of histologic information (smear with or without 5-ALA) further allows the surgical team to balance the potential functional risks within the global treatment plan. Therefore, the patient is kept at the center of the informed decision-making process.

Medial-tonsillar telovelar approach for resection of a superior medullary velum cerebral cavernous malformation: anatomical and tractography study of the surgical approach and functional implications.

BACKGROUND: Superior medullary velum cerebral cavernous malformations pose a challenge in terms of appropriate microsurgical approach. Safe access to this deep location as well as preservation of surrounding anatomical structures, in particular the superior cerebellar peduncle just lateral to the superior medullary velum and the dentate nuclei, is paramount to achieve a good functional outcome. METHODS: Cadaveric dissections provide useful knowledge of the normal anatomy while tractography allows a better understanding of the individual anatomy in the presence of a lesion. The medial-tonsillar telovelar approach provides a feasible corridor for accessing superior velum cerebral cavernous malformations without compromising the fibres contained in the superior cerebellar peduncle. The major cerebellar efferents-cerebello-rubral, cerebello-thalamic and cerebello-vestibular tracts-and afferents, anterior spinocerebellar, tectocerebellar and trigeminocerebellar tracts, within the superior cerebellar peduncle are preserved, and the dentate nuclei are not affected. RESULTS AND CONCLUSION: A retraction-free exposure through this natural posterior fossa corridor allows the patient with the anatomical and functional subtract to make a good functional recovery by minimizing the risk of a superior cerebellar syndrome, ataxia, tremor and dysmetria; decomposition of movement in the ipsilateral extremities, nystagmus and hypotonia; or akinetic mutism, reduced or absent speech with onset within the first post-operative week.

Somatotopy of corticospinal tract fibres of the intercostal muscles: report of a case and review of literature.

This study aimed at describing the first case of subcortical stimulation of the corticospinal tract leading to selective contraction of the intercostal muscles during surgery for removal of a tumour centred in the right central lobule/supplementary motor area. A 53-year-old male presented with partial motor seizures. Imaging demonstrated a low-grade glioma affecting the posterior aspect of the superior and middle frontal gyri and invading the precentral gyrus. Preoperative motor Transcranial Magnetic Stimulation and advanced diffusion tractography were performed to establish the relationship of the tumour with the motor cortex and corticospinal tract. Intraoperative motor mapping and monitoring were performed with monopolar stimulation ("train of 5" technique). At the posterior margin of resection, subcortical stimulation demonstrated a selective response from intercostal muscles, medial to responses from the lower limb and lateral to responses from the upper limb. PubMed literature search was performed to identify any case reporting similar findings. There were no cases previously reported in the literature. The location of the subcortical response for intercostal muscles confirms the somatotopy of the corticospinal tract. Intercostal muscles are controlled by selective fibres within the corticospinal tract. Damage to these fibres can lead to paralysis of voluntary respiratory muscles. Further studies are needed to define the cortico-subcortical network controlling voluntary respiratory muscles.

Grade II Sylvian fissure meningiomas without dural attachment: case report and review of the literature.

Sylvian fissure meningiomas (SFMs) represent a rare subgroup of nondural-based tumors arising from the meningothelial cells within the arachnoid of the Sylvian fissure. SFMs are more frequent in young males, usually manifest with seizures and display the same radiological features of meningiomas in other locations. Although the absence of dural attachment makes these tumors suitable for a complete resection, their anatomical relationships with the middle cerebral artery branches have impaired its achievement in half of them. To the best of our knowledge, only five atypical WHO grade II SFMs have been previously described. We provide a literature review of SFMs WHO grades I-II and discuss common characteristics and surgical challenges we found in a similar case.

Posterior longitudinal ligament and its implications in intradural cervical disc herniation: Case report and review of the literature.

BACKGROUND: Intradural disc herniations (IDH) are rare, particularly in the cervical spine, where they account for less than 5% of all discs. Adhesions between the ossified/calcified posterior longitudinal ligament (OPLL), dura, and ossified/calcified disc herniations increase the complexity of resecting these cervical lesions. CASE DESCRIPTION: A 42-year-old male presented with a rapidly progressive cervical myelopathy over a 2-month period. This was attributed to an ossified/calcified intradural cervical disc herniation in conjunction with OPLL. The anterior cervical discectomy and fusion (ACDF) resulted in a dural defect but there was no cerebrospinal fluid (CSF) fistula as the arachnoid membrane remained intact. Had there been a CSF leak, it would have warranted both wound-peritoneal (WP) and lumbo-peritoneal shunts (LP). The surgeons should have anticipated that a CSF leak would likely occur prior to performing the ACDF, and should have prophylactically prepared and draped the abdomen for a potential WP, followed by a LP shunt. Three months postoperatively, the patient's proprioceptive deficit improved, and he almost completely recovered motor function. CONCLUSION: Performing an ACDF for resection of an intradural calcified/ossified disc with OPLL often results in both a dural defect and CSF fistula. As the arachnoid membrane rarely remains intact, the spine surgeon should be prepared to immediately perform both a WP shunt, and subsequently, an LP. In this case, following an ACDF, resection of an intradural ossified disc with OPLL resulted in an isolated dural defect without a CSF fistula and did not require no dural repair or shunting procedures.

The role of preoperative deep vein thrombosis screening in neurooncology.

OBJECTIVEVenous thromboembolism (VTE) is a major cause of morbidity in patients undergoing neurosurgical intervention. The authors postulate that the introduction of a routine preoperative deep vein thrombosis (DVT) screening protocol for patients undergoing neurosurgical intervention for brain tumors would result in a more effective diagnosis of DVT in this high-risk subgroup, and subsequent appropriate management of the condition would reduce pulmonary embolism (PE) rates and improve patient outcomes.METHODSThe authors conducted a prospective study of 115 adult patients who were undergoing surgical intervention for a brain tumor. All patients underwent preoperative lower-limb Doppler ultrasonography scanning for DVT screening. Patients with confirmed DVT underwent a period of anticoagulation therapy, which was stopped prior to surgery. An inferior vena cava (IVC) filter was inserted to cover the perioperative period during which anticoagulation therapy was avoided due to bleeding risk before restarting the therapy at a later date. Patients underwent follow-up performed by a neurooncology multidisciplinary team, and subsequent complications and outcomes were recorded.RESULTSSeven (6%) of the 115 screened patients had DVT. Of these patients, one developed postoperative PE, and another had bilateral DVT postoperatively. None of the patients without preoperative DVT developed VTE postoperatively. Age, symptoms of DVT, and previous history of VTE were significantly higher in the group with preoperative DVT. There were no deaths and no complications from the anticoagulation or IVC filter insertion.CONCLUSIONSPreoperative screening for DVT is a worthwhile endeavor in patients undergoing neurosurgical intervention. A multidisciplinary approach in management of anticoagulation and IVC filter insertion is safe and can minimize further VTE in such patients.

Multiple brain metastases: a surgical series and neurosurgical perspective.

Despite review papers claim for radical treatment of oligometastatic patients, only few surgical series have been published. In this study, we analyze results and actual role of surgical resection for the management of patients with multiple brain metastases. This retrospective study compares surgical results of two groups of patients consecutively treated in our Institute from January 2004 to June 2015. The first group comprises all 32 patients with multiple brain metastases with only 2-3 lesions who underwent surgical resection of all lesions; the second group comprises 30 patients with a single surgically treated brain mestastasis compatible with the first group (match-paired control series). Median survival was 14.6 months for patients with multiple brain metastases (range 1-28 months) and 17.4 months for patients with a single brain metastasis (range 4-38 months); the difference was not statistically significant (P = 0.2). Neurological condition improved in 59.4% of patients with multiple metastases, it remained unchanged in 37.5% and worsened in 3.1%. In our series, selected patients with only 2-3 lesions with well-controlled systemic disease, life expectancy of more than 3 months, Karnofsky's performance status > 60, and surgically accessible lesions, benefited from surgical treatment in terms of survival and quality of life, with reduction or disappearance of significant neurological deficits. The prognosis for these patients is similar to that of patients with a single metastasis. It seems that patients with breast cancer included in our series had the worst prognosis if compared to other histotypes.

Two-year experience of multi-disciplinary team (MDT) outcomes for brain metastases in a tertiary neuro-oncology centre.

Brain metastases (BMs) are the most common intracranial tumour in adults and form a significant proportion of the neuro-oncology workload. Their management has progressed significantly in the last few decades but a gold-standard evidence-based management strategy has not been defined to date and several guidelines based on available evidence exist to support clinical decision-making. This paper evaluates the decision-making process of the neuro-oncology multi-disciplinary team (MDT) in a tertiary neuro-oncology centre over a two-year period. A retrospective review of all patients with BM discussed in the MDT was conducted. Data on patient demographics, tumour characteristics and MDT decision were collected from the MDT database, clinical notes and imaging studies. Patients were stratified into the three recursive partitioning analysis (RPA) classes and according to the graded prognostic assessment (GPA) score. MDT decisions were analysed by RPA class and for GPA score as well as single versus multiple BM. There were 362 patients with BM, representing 22% of the total cases discussed at the MDT. Decision-making was largely consistent with available guidelines. A concrete treatment decision was reached in 77.5% of patients and 32.2% of these received neurosurgical input. More patients with solitary BM underwent surgery compared to multiple BM (p = 0.001), and more patients in RPA classes I and II had surgical resection compared to class III (p = 0.005 and 0.001, respectively). Surgical patients also had higher GPA scores compared to palliative patients (p = 0.005). A greater absolute number and proportion of patients in RPA class II vs. class I underwent neurosurgical intervention. These patients were stratified into class II because of their age but would otherwise have been placed into class I. Survival data were available for 195 patients (53.8%) at 1 year post MDT discussion. A pattern of declining survival was observed along RPA classes which was statistically significant (p = 0.0025). Median survival was 4.7 (0-41), 3.7 (0-23), and 2.5 (range 0-24) months for RPA class I, II and III respectively. A similar pattern that did not reach statistical significance was found between GPA scores (p = 0.101). Median survival was 3 (0-13), 4.6 (range 0-41), and 4.6 (0-35) months for GPA scores 0-1.0, 1.5-2.5 and 3-4.0, respectively. Patient selection was generally in accordance to RPA class and GPA scoring, with the exception of surgery offered to elderly patients: this can be explained by the increasing number of otherwise fit patients as population ages.

Commentary: Giuseppe Campani (1635-1715, Rome, Italy): the First Use of a Microscope in Medicine and Surgery.

Giuseppe Campani (1635-1715) was a polymath in Rome, Italy, during the Scientific Revolution in the XVIIth century. In particular, he forged the screw barrel microscope and was manufacturing his own lenses for microscopes and telescopes. He mastered the art of lens grinding. Those lenses have been analyzed with modern methods and turned out to be of extremely good quality, shining light on the fact that Giuseppe Campani mastered the theories of optics. Moreover, in a letter that Giuseppe Campani sent to Pope Innocent XI, he clearly described the use of a microscope for the examination of wounds of legs. This letter dates back to 15 August 1686 and is the first evidence of the use of microscopes to analyze wounds, sores, and anatomic specimens in medical and surgical settings. MG Yasargil previously showed the lithography accompanying this letter and was the first to recognize its great importance. We accessed this original letter in the Vatican Library, and for the first time we have translated it from Latin to English in order to unveil its significance in the context of the Scientific Revolution and the history of medicine and surgery.

5-ALA fluorescence in intraparenchymal endodermal cysts.

In recent years, new indications have been suggested for 5-ALA, particularly for cystic lesions. We report the use of 5-ALA fluorescence in an intraparenchymal supratentorial endodermal cyst of a 52-year-old female presenting with headache, progressive right side hemiparesis and anomic aphasia. She underwent an image-guided 5-ALA-assisted left minicraniotomy for fenestration of the cystic lesion into the ventricular system. The capsule of the cyst was noted to fluoresce with 5-ALA. She recovered from the previous deficits and the cyst decreased in size. To the best of our knowledge, this is the first time 5-ALA fluorescence is reported in a case of endodermal cyst.

Third-ventricle enterogenous cyst presentation mimicking a colloid cyst: uncommon presentation of a rare disease and literature review.

Enterogenous cysts (ECs) are endodermal lesions resulting from splitting anomalies in the neuroenteric canal. We report the case of a 64-year-old patient who presented with a sudden headache followed by collapse. Brain computed tomography revealed a hyperdense lesion in the anterior part of the third ventricle with obstructive hydrocephalus. A presumptive diagnosis of colloid cyst was made and he underwent a right transcortical approach for lesion resection. The histopathological examination revealed an EC. ECs are common lesions in the cervical-thoracic spine but rare in the supratentorial compartment with only two previously described cases occurring in the third ventricle.

Mini Transsternal Approach to the Anterior High Thoracic Spine (T1-T4 Vertebrae).

Purpose. The anterior high thoracic spine is one of the most complex segments to be accessed surgically due to anatomical constraints and transitional characteristics. We describe in detail the mini transsternal approach to metastatic, infective, traumatic, and degenerative pathologies of T1 to T4 vertebral bodies. We analyse our surgical series, indications, and outcomes. Methods. Over a 5-year period 18 consecutive patients with thoracic myelopathy due to metastatic, infective, traumatic, and degenerative pathologies with T1 to T4 vertebral bodies involvement received a mini transsternal approach with intraoperative monitoring. Frankel scoring system was used to grade the neurological status. Results. Mean follow-up was 40 months. 78% patients improved in Frankel grade after surgery and 22% patients remained unchanged. Average operation time was 210 minutes. There were no intraoperative complications. One patient developed postoperative pneumonia successfully treated with antibiotics. Conclusion. The mini transsternal is a safe approach for infective, metastatic, traumatic, and degenerative lesions affecting the anterior high thoracic spine and the only one allowing an early and direct visualisation of the anterior theca. This approach overcomes the anatomical constraints of this region and provides adequate room for optimal reconstruction and preservation of spinal alignment in the cervicothoracic transition zone with good functional patient outcomes.

Lumbar Endoscopic Microdiscectomy: Where Are We Now? An Updated Literature Review Focused on Clinical Outcome, Complications, and Rate of Recurrence.

Endoscopic disc surgery (EDS) for lumbar spine disc herniation is a well-known but developing field, which is increasingly spreading in the last few years. Rate of recurrence/residual, complications, and outcomes, in comparison with standard microdiscectomy (MD), is still debated and need further data. We performed an extensive review based on the last 6 years of surgical series, systematic reviews, and meta-analyses reported in international, English-written literature. Articles regarding patients treated through endoscopic transforaminal or interlaminar approaches for microdiscectomy (MD) were included in the present review. Papers focused on endoscopic surgery for other spinal diseases were not included. From July 2009 to July 2015, we identified 51 surgical series, 5 systematic reviews, and one meta-analysis reported. In lumbar EDS, rate of complications, length of hospital staying, return to daily activities, and overall patients' satisfaction seem comparable to standard MD. Rate of recurrence/residual seems higher in EDS, although data are nonhomogeneous among different series. Surgical indication and experience of the performing surgeon are crucial factors affecting the outcome. There is growing but still weak evidence that lumbar EDS is a valid and safe alternative to standard open microdiscectomy. Statistically reliable data obtained from randomized controlled trials (better if multicentric) are desirable to further confirm these results.

[Stenting versus carotid endarterectomy for carotid stenosis. A single center experience]. / Stenting Carotideo e Endoarterectomia Carotidea Esperienza di un singolo Centro.

AIM: The objective was to compare Carotid Endarterectomy (CEA) with Carotid Artery Stenting (CAS) in terms of efficacy and safety in patients with symptomatic and asymptomatic extracranial carotid stenosis. MATERIALS: This study enrolled 285 patients with symptomatic and asymptomatic carotid stenosis that underwent either to CAS or CEA. The primary end-points were death, stroke and myocardial infarction. The secondary end-points were restenosis and nerve injury. The Data emerged from the follow-up at 1,3,6,12,24 months that provided for clinical and EcocolorDoppler monitoring. A separate analyse was performed evaluating the prediction of the Ultrasonographic appearance of the atheroma on the symptomatic nature of the lesion. RESULTS: The percentage of neurological symptomatology in the periprocedural period was higher in CAS than in CEA group (9% vs 3%). We didn't report any case of periprocedural death. The results from the follow-up are: myocardial infarction 5% CAS vs 7% CEA; stroke 5% CAS vs 4% CEA; restenosis 3% CAS vs 6% CEA; nerve injury 0% CAS vs 1% CEA; mortality 0% CAS vs 1% CEA. DISCUSSION: CEA is the gold standard for treatment of significant carotid stenosis, although endovascular technique is emerging as a less invasive alternative. CAS has presented a less frequence of myocardial infarction, nerve injury and long-term mortality, but it showed an higher percentage of neurological events both in short and long-term. This last aspect is correlated with the plaque structure. Ultrasonographic study of the atheroma has become a defining moment in the choice of the therapeutic strategy.

Quality of care and rehospitalization rate in the last stage of disease in brain tumor patients assisted at home: a cost effectiveness study.

UNLABELLED: Despite aggressive multimodality treatment the prognosis of patients with primary brain tumors (BT) remains poor. At present, there are no data about the role of palliative home-care services and their impact on quality of care. We report the results of a pilot project of palliative home care for BT patients started in 2000 in the National Cancer Institute Regina Elena of Rome. We report also the result of a cost/effectiveness analysis utilizing administrative data on re-hospitalization rate in the last two months of life. METHODS: Since October 2000 until December 2009, 572 patients have been followed by our home care staff. Among 394 patients who died, 276 (70%) were followed at home until death. A cost/effectiveness analysis was carried out evaluating the rehospitalization rate in the last 2 months of life in a subgroup of patients (group 1 assisted at home, 72 patients; group 2 not assisted at home, 71). The number of hospital readmission in the last 2 months of life, and length and cost of hospitalization were retrospectively analyzed from hospital discharge records. RESULTS: Hospitalization rate of group 1 (16.7%) was lower than group 2 (38%) (95% CI: 0.18-0.65, p = 0.001). Costs of hospitalization also differed substantially: 517 Euros (95% CI: 512-522) in group 1 vs 24, 076 Euros (95%: 24,040-24,112 Euros) in group 2. CONCLUSION: Home-care may represent an alternative to in-hospital care for the management of brain tumor patients and may improve the end-of-life quality of care.