Handbook of clinical neurology
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Developmental venous anomalies (DVAs) are relatively common lesions, present in up to 3% of the population. The defining characteristic of these lesions is the confluence of radially oriented veins into a single dilated venous channel. DVAs are also known as cerebral venous angiomas, cerebral venous malformations, and cerebral venous medullary malformations. ⋯ DVAs are congenital lesions thought to arise from aberrations that occur during venous development, but continue to provide the normal venous drainage to the cerebral territory in which they reside. Although the natural history of DVAs is benign, they may be associated with cavernous malformations or other vascular abnormalities, which can lead to hemorrhage in the vicinity of the DVA. Surgical or endovascular obliteration of DVAs carries a significant risk of venous infarction; thus, conservative management is the treatment of choice for patients with these lesions.
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The cerebrospinal fluid (CSF) space consists of the intracerebral ventricles, subarachnoid spaces of the spine and brain (e.g., cisterns and sulci), and the central spinal cord canal. The CSF protects the central nervous system (CNS) in different ways involving metabolic homeostasis, supply of nutrients, functioning as lymphatic system, and regulation of intracranial pressure. CSF is produced by the choroid plexus, brain interstitium, and meninges, and it circulates in a craniocaudal direction from ventricles to spinal subarachnoid space from where it is removed via craniocaudal lymphatic routes and the venous system. ⋯ The extracellular space volume, potassium buffering, CSF circulation, and interstitial fluid absorption are mainly regulated by aquaporin-4 channels, which are abundantly located at the blood-brain and brain-CSF interfaces. The composition of CSF shows a high dynamic range, and the levels of distinct proteins vary due to several influencing factors, such as site of production (brain or blood-derived), site of sampling (ventricular or lumbar), CSF flow rate (BCB function), diurnal fluctuations of CSF production rate, and finally, molecular size of blood-derived proteins (IgM vs. albumin) and circadian rhythm (glucose, prostaglandin D synthase). Alterations of lumbar CSF are mainly influenced by processes of the CNS located adjacent to the ventricular and spinal CSF space and less by pathologies in cortical areas remote from the ventricles.
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Arteriovenous malformations (AVMs) of the brain are diverse lesions that vary widely in location, size, and complexity. Treatment options for AVMs are correspondingly complex. Complete elimination of an AVM is required to protect patients from future hemorrhage. ⋯ Some AVMs can be managed conservatively, whereas others can be managed with microsurgical resection, radiosurgical ablation, or endovascular embolization, either individually or in combination. Some AVMs may also be treated with partial therapy to reduce the risk of hemorrhage or to ameliorate symptoms. In this chapter, we review the key factors that influence whether and how to manage AVMs with multimodality treatment.
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Review Case Reports
Natural history of cerebral cavernous malformations.
Cerebral cavernous malformations (CCM) are vascular abnormalities of the central nervous system with an incidence of 0.4-0.5% and an annual rate of hemorrhage ranging from 0.7% to 1%. Most lesions are located in the cerebral hemisphere but some occur in deeper locations such as the basal ganglia and pons. The most common symptoms during presentation are headache, seizures, and focal neurologic deficits. ⋯ This finding, however, is not consistent in all natural history studies evaluated. During follow-up, the most important and consistent risk factor for rebleed was a prior hemorrhage. Here, we provide an indepth but concise review of the literature regarding the natural history of CCMs.
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The human prion diseases comprise Creutzfeldt-Jakob disease, variably protease-sensitive prionopathy, Gerstmann-Sträussler-Scheinker disease, fatal familial insomnia, and kuru. Each is a uniformly fatal rare neurodegenerative disease in which conformational changes in the prion protein are thought to be the central pathophysiologic event. The majority of cases of human prion diseases occur worldwide in the form of sporadic Creutzfeldt-Jakob disease and a minority of around 10-15% are associated with mutations of the prion protein gene, termed PRNP, in the forms of genetic Creutzfeldt-Jakob disease, Gerstmann-Sträussler-Scheinker disease, and fatal familial insomnia. ⋯ Despite having a high public profile, human prion diseases are both rare and heterogeneous in their clinicopathologic phenotype, sometimes making a diagnosis challenging. A combined clinical, genetic, neuropathologic, and biochemical approach to diagnosis is therefore essential. The intensive study of these diseases continues to inform on neurodegenerative mechanisms and the role of protein misfolding in more common neurodegenerative diseases such as Parkinson disease and Alzheimer disease.