Giuseppe Maria Della Pepa

Spinal cord stimulation and cerebral hemodynamics: updated mechanism and therapeutic implications

The effects of spinal cord stimulation (SCS) on cerebral blood flow (CBF) are well known based on experimental investigations, and its vasodilator effect on peripheral arteries is widely used in clinical settings in the treatment of peripheral vascular disease. Since Hosobuchi’s [Appl Neurophysiol 1985;48:372–376] first observations on the effects of SCS on CBF were published 22 years ago, many advances have been made in understanding SCS-mediated effects on CBF. This paper reviews the main laboratory observations and analyzes the most significant neurophysiological theories on the SCS-mediated effect on CBF. Most significant experimental data have been discussed, with specific reference to possible mechanisms such as ‘functional reversible sympathectomy’, cerebral infarction and related ischemic edema, hemodynamic deterioration in experimental combined ischemic-traumatic brain injury and cerebral vasospasm. The authors revised the published experiences in humans with hypoperfusion syndromes and ‘adjuvant’ locoregional CBF increase in chemotherapy of brain tumors. SCS represents a new perspective in challenging neurosurgical clinical fields such as cerebral ischemia and vasospasm, and seems promising as a new trend of functional neurosurgery in cerebrovascular diseases.

Sudden onset of Chiari malformation Type I in previously asymptomatic patients

Chiari malformation Type I (CM-I) is usually suspected in patients with slowly progressing neurological symptoms. However, in some instances, especially if syringomyelia is associated, an abrupt clinical onset is reported and is accompanied by an acknowledged risk of potentially severe clinical signs or even sudden death. Little is known about such a critical course in CM-I/syringomyelia complex. The authors describe 3 challenging cases of the abrupt onset of CM-I/syringomyelia to reveal more information on the clinical presentation and pathogenetic mechanisms of this sudden and potentially severe clinical phenomenon: a 38-year-old man experienced acute respiratory failure requiring intubation following acute decompensation of hydrocephalus associated with Noonan syndrome, a 1-year-old boy had sudden hemiparesis and Horner syndrome after a minor head/neck injury, and a 2.5-year-old boy presented with quickly progressing tetraplegia and dyspnea after a mild flexion and extension neck injury a few hours before. All 3 patients showed a CM-I/syringomyelia complex at diagnosis, and all of them had a good neurological outcome after surgery despite the ominous clinical presentation.

Craniotomy repair with the retrosigmoid approach: the impact on quality of life of meticulous reconstruction of anatomical layers

IntroductionVarious cranial repairs have been described to limit the incidence of cerebrospinal fluid (CSF) leak, the rate of infections, postoperative headache and local discomfort in patients undergoing cerebello-pontine angle surgery.Materials and methodsThe aim of this study was to evaluate the impact of a feasible craniotomy procedure and cranial repair technique, which does not require bone replacers or filling materials, on postoperative outcome. We analysed postoperative results in a series of 34 patients undergoing cerebello-pontine angle surgery.Discussion and conclusionsWe observed a statistically significant reduced incidence of local discomfort, postoperative headache and CSF leak in patients who underwent such a reconstructive technique compared to those undergoing retrosigmoid craniectomy.

Neuromodulation of Vegetative State through Spinal Cord Stimulation: Where Are We Now and Where Are We Going?

Background: Vegetative state (VS) is a complex condition that represents a challenging frontier for medicine and neuroscience research. Nowadays there is no scientifically validated treatment for VS patients, and their chronic long-term assistance is very demanding for healthcare systems worldwide. Objectives: The present paper is a systematic review of the role of spinal cord stimulation (SCS) as a treatment of patients with VS. Methods: Published literature on this topic was analyzed systematically. Clinical and epidemiological characteristics of VS, present therapeutic options and social costs of VS were also evaluated. Results: Only 10 papers have been published since 1988, and overall 308 VS patients have been treated with SCS worldwide; 51.6% displayed a clinical improvement and an amelioration of the environmental interaction. These effects are probably mediated by the stimulation of the reticular formation-thalamus-cortex pathway and by cerebral blood flow augmentation induced by SCS. Conclusions: The experience on this topic is still very limited, and on this basis it is still hard to make any rigorous assessment. However, the most recent experiments represent significant progress in the research on this topic and display SCS as a possible therapeutic tool in the treatment of VS.

The role of laminoplasty in preventing spinal deformity in adult patients submitted to resection of an intradural spinal tumor. Case series and literature review

OBJECTIVE Laminectomy has normally been used as a standard approach for intradural spinal tumors but this procedure is associated with spinal instability and deformity. Laminoplasty was developed to overcome these limitations. Controversies still exist regarding its actual role in preventing spinal deformity in adults. The aim of our study was to determine the impact of laminoplasty on the prevention of spinal deformitys onset or worsening in adult patients submitted to intradural spinal tumors resection. METHODS We retrospectively reviewed the data of 43 consecutive adult patients, who underwent either laminectomy or laminoplasty for spinal intradural tumor resection, between January 2006 and May 2011. We evaluated the role of sex, spinal segment (cervical, thoracic, lumbar), tumor location (intra- or extra-medullary), procedure (laminoplasty or laminectomy), number of treated levels (≤2 vs >2), presence of pre-operative deformity and pre-operative Modified McCormick Scale (≤2 vs >2) in the development or worsening of spinal deformity, using Fishers exact test and multivariate logistic regression analysis. RESULTS Nine patients developed deformity or experienced a worsening of pre-operative deformity at latest follow-up. Among the considered potential prognostic factors, laminectomy (p=0.03) and evidence of pre-operative spinal deformity (p=0.009) were significantly associated with new-onset or worsening of spinal deformity. At logistic regression analysis, only the performed surgical procedure emerged as independent prognostic factor (p=0.044). No CSF leak was recorded in the laminoplasty cohort. CONCLUSIONS No new-onset spinal deformities, no CSF leaks and a lower rate of spinal deformity progression were observed after laminoplasty for intradural intra- or extra-medullary tumor resection.

Angio-Architectural Features of High-Grade Intracranial Dural Arteriovenous Fistulas: Correlation With Aggressive Clinical Presentation and Hemorrhagic Risk

BACKGROUND High-grade dural arteriovenous fistulas (dAVFs) can present shunts with very different angio-architectural characteristics. Specific hemodynamic factors may affect clinical history and determine very different clinical courses. OBJECTIVES To evaluate the relationship between some venous angio-architectural features in high-grade dAVFs and clinical presentation. Specific indicators of moderate or severe venous hypertension were analyzed, such as altered configurations of the dural sinuses (by a single or a dual thrombosis), or overload of cortical vessels (restrictions of outflow, pseudophlebitic cortical vessels, and venous aneurysms). METHODS The institutional series was retrospectively reviewed (49 cases), and the pattern of venous drainage was analyzed in relationship with clinical presentation (benign/aggressive/hemorrhage). RESULTS Thirty-five of 49 cases displayed cortical reflux (high-grade dAVFs). This subgroup displayed a benign presentation in 31.42% of cases, an aggressive in 31.42%, and hemorrhage in 37.14%. CONCLUSIONS Our data confirm that within high-grade dAVFs, 2 distinct subpopulations exist according to severity of clinical presentation. Some indicators we examined showed correlation with aggressive nonhemorrhagic manifestations (outflow restriction and pseudophlebitic cortical vessels), while other showed a correlation with hemorrhage (dual thrombosis and venous aneurysms). Current classifications appear insufficient to identify a wide range of conditions that ultimately determine the organization of the cortical venous drainage. Intermediate degrees of venous congestion correlate better with the clinical risk than the simple definition of cortical reflux. The angiographic aspects of venous drainage presented in this study may prove useful to assess dAVF hemodynamic characteristics and identify conditions at higher clinical risk.

Myeloid sarcoma with megakaryoblastic differentiation mimicking a sellar tumor

Myeloid sarcoma (MS) is a localized extra‐medullary tumor mass of immature myeloid cells, arising de novo or related to acute myeloid leukemia, of which it can be a forerunner, a coinciding or late event. Less commonly, MS represents an acute blastic transformation of myelodysplastic syndromes or myeloproliferative neoplasms. This rare condition commonly consists of a proliferation of more or less immature cells with a myeloid immunophenotype, very exceptional cases showing a megakaryoblastic or erythroid differentiation. The most common localization of MS is the skin, lymph node, soft tissues and bones, but CNS involvement is exceedingly rare, with no cases reported in the sellar region. We report a 54‐year‐old man, affected by myeloproliferative neoplasm, JAK2 V617F‐positive of 13 years duration, who acutely presented with a third cranial nerve palsy; neuroradiology documented a space‐occupying lesion at the level of the sellar, upper clival and right parasellar regions, that was sub‐totally removed with a trans‐sphenoidal approach. The histological examination documented a proliferation of large, blastic cells, frequently multinucleated; a diagnosis of MS with megakaryoblastic differentiation, arising in a background of chronic idiopathic myelofibrosis, was suggested by immunohistochemistry, owing to CD42b, CD45, CD61 and LAT (linker for activation of T cells) positivity. In addition, homozygous JAK2 V617F mutation was detected from the myeloid sarcoma specimen. A few weeks after surgery, an acute blastic leukemic transformation occurred and, despite chemotherapy, the patient died 2 months after surgery. To the best of our knowledge, this is the first MS case with megakaryoblastic differentiation arising within the CNS.

Galea-pericranium dural closure: Can we safely avoid sealants?

OBJECTIVE Dural closure is one of the most critical steps in neurosurgical procedures as it prevents many common postoperative complications. Methods of dural closure include the use of allogenic, autogenic, xenogenic, absorbable or synthetic materials together with sealant/glues or hemostatic compounds. Most common autogenic graft is galea-pericranium. This study aims to demonstrate how the intrinsic properties of the galea-pericranium make effectively useless the application of any glue in order to ensure the watertight integrity of the graft. PATIENTS AND METHODS 276 cases were included in the study. Postoperative dural-closure related complication in patients subjected to duraplasty were analysed in three groups undergoing different duraplasty techniques: galea-pericranium graft without sealants, galea-pericranium graft plus sealant, non-autologous dural patch plus sealant. RESULTS No statistically significant differences between the three groups were observed in terms of subcutaneous fluid collection rate, CSF fistulas, brain abscesses, subdural empyemas, wound dehiscence, radiotherapic sequelae. CONCLUSIONS Our study shows that galea-pericranium alone (without sealants) is comparable to other duraplasty techniques that involve the use of sealants or of non-autologous pathches in terms of long term postoperative results.

Intraorbital and intracanalicular ophthalmic artery aneurysms. Literature review and report of a case

Abstract This paper reviews literature about intraorbital ophthalmic artery aneurysms discussing presentation, aetiology and treatment options. In addition we report on a case of intraorbital ophthalmic artery aneurysm with acute onset of headache, visual loss and right eye ophthalmoplegia.

Integration of Real-Time Intraoperative Contrast-Enhanced Ultrasound and Color Doppler Ultrasound in the Surgical Treatment of Spinal Cord Dural Arteriovenous Fistulas

BACKGROUND In the surgical treatment of spinal dural arteriovenous fistulas (DAVFs), intraoperative definition of anatomic characteristics of the DAVF and identification of the fistulous point is mandatory to effectively exclude the DAVF. CASE DESCRIPTION Intraoperative ultrasound and contrast-enhanced ultrasound integrated with color Doppler ultrasound was applied in the surgical setting for a cervical DAVF to identify the fistulous point and evaluate correct occlusion of the fistula. CONCLUSIONS Integration of intraoperative ultrasound and contrast-enhanced ultrasound is a simple, cost-effective technique that provides an opportunity for real-time dynamic visualization of DAVF vascular patterns, identification of the fistulous point, and assessment of correct exclusion. Compared with other intraoperative tools, such as indocyanine green videoangiography, it allows the surgeon to visualize hidden anatomic and vascular structures, minimizing surgical manipulation and guiding the surgeon during resection.