Neurosurgery
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Chiari malformations are regarded as a pathological continuum of hindbrain maldevelopments characterized by downward herniation of the cerebellar tonsils. The Chiari I malformation (CMI) is defined as tonsillar herniation of at least 3 to 5 mm below the foramen magnum. Increased detection of CMI has emphasized the need for more information regarding the clinical features of the disorder. ⋯ These data support accumulating evidence that CMI is a disorder of the para-axial mesoderm that is characterized by underdevelopment of the posterior cranial fossa and overcrowding of the normally developed hindbrain. Tonsillar herniation of less than 5 mm does not exclude the diagnosis. Clinical manifestations of CMI seem to be related to cerebrospinal fluid disturbances (which are responsible for headaches, pseudotumor-like episodes, endolymphatic hydrops, syringomyelia, and hydrocephalus) and direct compression of nervous tissue. The demonstration of familial aggregation suggests a genetic component of transmission.
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Basal ganglia and thalamic arteriovenous malformations (AVMs) show a poor natural history and have proven difficult to treat. We report the safety and efficacy of presurgical and preradiosurgical embolization of these deep central lesions and describe the contribution of embolization to multimodality treatment. ⋯ Endovascular embolization plays an important role in multimodality treatment of AVMs involving the basal ganglia and/or thalamus. Embolization can result in obliteration of a significant volume of the AVM and may allow complete obliteration of the AVM when combined with microsurgical resection and/or stereotactic radiosurgery.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Prognostic value and determinants of ultraearly angiographic vasospasm after aneurysmal subarachnoid hemorrhage.
A small number of patients with aneurysmal subarachnoid hemorrhage have angiographic evidence of cerebral vasospasm within 48 hours of the onset of hemorrhage. The present study analyzes the prognostic value and determinants of this ultraearly angiographic finding. ⋯ Our analysis suggests that patients with angiographic evidence of vasospasm at admission are at high risk for both symptomatic vasospasm and poor outcome. We also found that early surgery did not aggravate this risk.
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Arnold Chiari Type I malformation usually presents as headache, arm numbness, dysesthesia, upper weakness, or gait difficulty. We report a case of Chiari malformation presenting as a left trigeminal neuralgia. ⋯ The trigeminal neuralgia could be attributable to a compression of the trigeminal nucleus. The compression of the nucleus could explain both the pain and the regression after surgery. This is the second reported case of pure trigeminal neuralgia in Arnold Chiari malformation.
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Acute pupillary dilation in a head-injured patient is a neurological emergency. Pupil dilation is thought to be the result of uncal herniation causing mechanical compression of the IIIrd cranial nerve and subsequent brain stem compromise. However, not all patients with herniation have fixed and dilated pupils, and not all patients with nonreactive, enlarged pupils have uncal herniation. Therefore, we have tested an alternative hypothesis that a decrease in brain stem blood flow (BBF) is a more frequent cause of mydriasis and brain stem symptomatology after severe head injury. We determined the relation of BBF to outcome and pupillary response in patients with severe head injuries. ⋯ These findings suggest that pupillary dilation is associated with decreased BBF and that ischemia, rather than mechanical compression of the IIIrd cranial nerve, is an important causal factor. More important, pupil dilation may be an indicator of ischemia of the brain stem. If cerebral blood flow and cerebral perfusion pressure can be rapidly restored in the patient with severe head injury who has dilated pupils, the prognosis may be good.