Progress in neurological surgery
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We evaluated the role of Gamma Knife stereotactic radiosurgery in the multidisciplinary management of brain metastases ovarian and endometrial, prostate, thyroid, sarcoma, or unknown primary cancers. From a series of over 3,000 patients who had Gamma Knife radiosurgery for brain metastases we reviewed indications and outcomes in patients with less common cancer types. ⋯ Patients with thyroid metastases appear to live much longer with a more indolent course. Radiosurgery is an effective and safe minimally invasive option for patients with brain metastases from these less common primary origins.
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Hematogeneous spread of primary neoplasm can result in central nervous system (CNS) disease burden in various anatomically distinct regions; calvarial, pachymeningeal, leptomeningeal, and intraparenchymal. The choice of imaging modality is dependent on the individual clinical situation, but, largely depends on the patients overall clinical status and the information needed to make treatment decisions. Contrast-enhanced magnetic resonance (MR) imaging is the preferred imaging modality of choice; however, computed tomography (CT) is often utilized as the first-pass screening modality for CNS disease. ⋯ Proton magnetic resonance spectroscopic and dynamic susceptibility contrast-enhanced perfusion-weighted imaging are two physiologic sequences which add additional diagnostic information allowing for improved tumor characterization. Common pitfalls in evaluating for metastatic disease burden include the misidentification of non-neoplastic hematomas, remote microvascular ischemia, and acute onset of ischemic stroke. In the pediatric population, CNS metastases are rare; however, the onset of acute neurological symptoms in a child with known primary tumor should prompt imaging of the neuroaxis.
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The effect of peripheral neurostimulation has traditionally been attributed to the activation of non-noxious afferent nerve fibers (Aβ-fibers) thought to modulate Aδ and C-fiber-mediated nociceptive transmission in the spinal cord, compatible with the 'gate control theory of pain'. The concept has been extended since its initial description and more recent experimental evidence suggests that the analgesic effects of peripheral nerve stimulation in pain states such as in chronic headache require an interplay of multiple influences. ⋯ Beyond the concept of neuromodulation--decreasing excitation or increasing inhibition--a prerequisite of this arrangement is the convergence of different types of afferent activity and an intact descending modulatory network. In this review, we focus on the functional anatomy, pathophysiological mechanisms and neurophysiological and pharmacological findings elucidating the central mechanisms of peripheral nerve stimulation.
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Peripheral nerve stimulation (PNS) has been used for the treatment of neuropathic pain for more than 40 years. Recent interest in the utilization of this technique stems from the many modifications of the original procedure and the refinement of the available hardware. This rendered the procedure less traumatic and more effective, and thus more widely accepted as a neuromodulation technique for the treatment of various chronic pain syndromes including post-traumatic and postsurgical neuropathy, occipital neuralgia, and complex regional pain syndromes, and in relatively new indications for neuromodulation, such as migraines and daily headaches, cluster headaches. ⋯ We review the protocol of our approach including the surgical nuances for our implantation technique. Collaborative efforts in future research will lead to a growth in our clinical experience with the utilization of PNS and will help in identifying the best candidates for it. This, along with the development and refinement of the available hardware would lead to a more specific patient selection for each modality of treatment, increasing the efficacy and success of the intended treatment.
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Fibromyalgia is a condition marked by widespread chronic pain, accompanied by a variety of other symptoms, including sleep and fatigue disorders, headaches, disorders of the autonomic nervous system, as well as cognitive and psychiatric symptoms. It occurs predominantly in women and is often associated with other systemic or autoimmune diseases. ⋯ Greater occipital nerve stimulation has already been used successfully to treat occipital neuralgia and various primary headache syndromes. Testable hypothetical working mechanisms are proposed to explain the surprising effect of this treatment on widespread bodily pain.