Petroclival meningiomas and the petrosal approach.

As with other meningiomas, the goal of petroclival meningioma treatment should be curative total removal by achieving a Simpson I resection of the tumor, dura, and bone. Petroclival meningiomas particularly pose a great technical challenge because of their deep location and intimate relation with vital neurovascular structures. They require adequate exposure and trajectory to achieve total removal while minimizing the manipulation and risk to critical neurovascular structures, such as the vertebrobasilar system, the brainstem, and the cranial nerves. Here, we describe the indications and technical nuances of the posterior and combined posterior-anterior petrosal approaches for petroclival meningiomas.

Value of the Petromeatal Angle in Predicting Outcome of Translabyrinthine Resection of Vestibular Schwannomas.

BACKGROUND: Factors associated with extent of tumor resection (EOR) and facial nerve outcomes include tumor size, anterior extension of the tumor, patient age, and surgical approach. OBJECTIVE: To check whether preoperative measurement of the petromeatal (PMA), petroclival (PCA), and petrous-petrous (PPA) angles can help in predicting EOR, facial nerve outcome, and cerebrospinal fluid (CSF) leak occurrence in patients undergoing vestibular schwannoma (VS) surgery via the translabyrinthine approach (TLA). METHODS: A total of 75 patients were included in this retrospective study. Preoperative magnetic resonance imaging constructive interface in steady state and postcontrast T1-weighted sequences through the internal acoustic meatus were used to measure the PMA, PCA, and PPA. RESULTS: There was a statistically significant association between tumor size and EOR; every additional cm in tumor size decreases the odds of gross-total (GTR)/near-total (NTR) resection by 524% (P = .0000355).After controlling for tumor size, the logistic models revealed a significant effect of the angles on EOR. For example, in a patient with a 2-cm VS, every additional degree in PMA, PCA, and PPA increases the odds of GTR/NTR by 2.3% (P = .0000571), 4.05% (P = .0000397), and 0.37% (P = .0000438), respectively.After adjusting for tumor size, sex, and age, the effect of PMA on the occurrence of an immediate postoperative facial nerve deficit and CSF leak indicated a trend towards significance (P = .0581 and P = .0568, respectively). CONCLUSION: More obtuse petrous bone angles, namely PMA, PCA, and PPA, are good predictors of GTR or NTR in patients undergoing VS surgery via TLA and may be associated with better facial nerve outcomes and lower CSF leak occurrences.

Deep brain stimulation: foundations and future trends.

Deep brain stimulation (DBS) has emerged as a revolutionary treatment option for essential tremor (ET), Parkinson's disease (PD), idiopathic dystonia, and severe obsessive-compulsive disorder (OCD). This article reviews the historical foundations of DBS including basal ganglia pathophysiological models, classic principles of electrical stimulation, technical components of the DBS system, treatment risks, and future directions for DBS. Chronic high frequency stimulation induces a number of functional changes from fast physiological to slower metabolic effects and ultimately leads to structural reorganization of the brain, so-called neuroplasticity. Examples of each of these fast, slow, and long-term changes are given in the context of Parkinson's disease where these mechanisms have perhaps been the most intensely investigated. In particular, details of striatal dopamine release, expression of trophic factors, and a possible neuroprotective mechanism of DBS are highlighted. We close with a brief discussion of technical and clinical considerations for improvement. Deep brain stimulation will continue to offer a reversible and safe therapeutic option for a host of neurological conditions and remains one of the best windows into human brain physiology.

Contemplating stem cell therapy for epilepsy-induced neuropsychiatric symptoms.

Epilepsy is a debilitating disease that impacts millions of people worldwide. While unprovoked seizures characterize its cardinal symptom, an important aspect of epilepsy that remains to be addressed is the neuropsychiatric component. It has been documented for millennia in paintings and literature that those with epilepsy can suffer from bouts of aggression, depression, and other psychiatric ailments. Current treatments for epilepsy include the use of antiepileptic drugs and surgical resection. Antiepileptic drugs reduce the overall firing of the brain to mitigate the rate of seizure occurrence. Surgery aims to remove a portion of the brain that is suspected to be the source of aberrant firing that leads to seizures. Both options treat the seizure-generating neurological aspect of epilepsy, but fail to directly address the neuropsychiatric components. A promising new treatment for epilepsy is the use of stem cells to treat both the biological and psychiatric components. Stem cell therapy has been shown efficacious in treating experimental models of neurological disorders, including Parkinson's disease, and neuropsychiatric diseases, such as depression. Additional research is necessary to see if stem cells can treat both neurological and neuropsychiatric aspects of epilepsy. Currently, there is no animal model that recapitulates all the clinical hallmarks of epilepsy. This could be due to difficulty in characterizing the neuropsychiatric component of the disease. In advancing stem cell therapy for treating epilepsy, experimental testing of the safety and efficacy of allogeneic and autologous transplantation will require the optimization of cell dosage, delivery, and timing of transplantation in a clinically relevant model of epilepsy with both neurological and neuropsychiatric symptoms of the disease as the primary outcome measures.

Growth factor therapy sequesters inflammation in affording neuroprotection in cerebrovascular diseases.

INTRODUCTION: In recent years, accumulating evidence has demonstrated the key role of inflammation in the progression of cerebrovascular diseases. Inflammation can persist over prolonged period of time after the initial insult providing a wider therapeutic window. Despite the acute endogenous upregulation of many growth factors after the injury, it is not sufficient to protect against inflammation and to regenerate the brain. Therapeutic approaches targeting both dampening inflammation and enhancing growth factors are likely to provide beneficial outcomes in cerebrovascular disease. AREAS COVERED: In this mini review, we discuss major growth factors and their beneficial properties to combat the inflammation in cerebrovascular diseases. Emerging biotechnologies which facilitate the therapeutic effects of growth factors are also presented in an effort to provide insights into the future combination therapies incorporating both central and peripheral abrogation of inflammation. Expert commentary: Many studies discussed in this review have demonstrated the therapeutic effects of growth factors in treating cerebrovascular diseases. It is unlikely that one growth factor can be used to treat these complex diseases. Combination of growth factors and anti-inflammatory modulators may clinically improve outcomes for patients. In particular, transplantation of stem cells may be able to achieve both goals of modulating inflammation and upregulating growth factors. Large preclinical studies and multiple laboratory collaborations are needed to advance these findings from bench to bedside.