Handbook of clinical neurology
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Epilepsy is one of the most common neurologic disorders, affecting about 50 million people worldwide. The disease is characterized by recurrent seizures, which are due to aberrant neuronal networks resulting in synchronous discharges. The term epilepsy encompasses a large spectrum of syndromes and diseases with different etiopathogenesis. ⋯ Access of this clinically well-characterized neurosurgical material has provided neuropathologists with the opportunity to study a variety of structural brain abnormalities associated with epilepsy, by combining traditional routine histopathologic methods with molecular genetics and functional analysis of the resected tissue. This approach has contributed greatly to a better diagnosis and classification of these structural lesions, and has provided important new insights into their pathogenesis and epileptogenesis. The present chapter provides a detailed description of the large spectrum of histopathologic findings encountered in epilepsy surgery patients, addressing in particular the nonneoplastic pathologies, including hippocampal sclerosis, malformations of cortical development, Sturge-Weber syndrome, and Rasmussen encephalitis, and reviews current knowledge regarding the underlying molecular pathomechanisms and cellular mechanisms mediating hyperexcitability.
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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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Major neurologic morbidity, such as seizures and encephalopathy, complicates 20-30% of organ and stem cell transplantation procedures. The majority of these disorders occur in the early posttransplant period, but recipients remain at risk for opportunistic infections and other nervous system disorders for many years. ⋯ Drug neurotoxicity accounts for a significant proportion of complications, with posterior reversible leukoencephalopathy syndrome, primarily associated with calcineurin inhibitors (i.e., cyclosporine and tacrolimus), being prominent as a cause of seizures and neurologic deficits. A thorough evaluation of any patient who develops neurologic symptoms after transplantation is mandatory, since reversible and treatable conditions could be found, and important prognostic information can be obtained.
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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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Spinal cavernous malformations are intramedullary vascular lesions. They have low pressure and flow, so they may take many years to present with clinical symptoms. Because of their relatively benign nature, surgical intervention is not always indicated. ⋯ Sensory symptoms correlated with worse outcome. Given the natural history of spinal cavernous malformations, surgery may be considered for symptomatic patients, when general medical health and lesion location permit safe resection. The severity of symptoms must also be considered, as the natural history of the disease can be benign.