Acta neurochirurgica
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Acta neurochirurgica · Aug 2005
A morphometric analysis of the foramen magnum region as it relates to the transcondylar approach.
The transcondylar approach is being increasingly used to access lesions ventral to the brainstem and cervicomedullary junction. Understanding the bony anatomy of this region is important for this approach. The purpose of this study was to conduct a morphometric analysis of the hypoglossal canal (HC), occipital condyle (OC) and the foramen magnum (FM) as it pertains to the transcondylar approach. ⋯ The occipital condyle is frequently being drilled to expose lesions ventral to the brainstem. From our study, it is evident that the occipital condyle can be safely drilled for a distance of 12 mms from the posterior margin before encountering the hypoglossal canal. In 20% of the skulls the occipital condyle protrudes significantly into the foramen magnum. Wide and sagittally inclined occipital condyles, medially protruberant occipital condyles along with a foramen magnum index of more than 1.2 will require much more extensive bony resection than otherwise. With the availability of recent imaging techniques, it is possible to anticipate the extent of bony resection required in an individual case by using the above mentioned morphometric features.
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Acta neurochirurgica · Aug 2005
Case ReportsFusiform aneurysm of the vertebral artery presenting with hemifacial spasm treated by microvascular decompression.
We report a rare case of symptomatic hemifacial spasm caused by a fusiform vertebral artery aneurysm. A 59-year-old woman presented with left hemifacial spasm of 18 months duration. ⋯ Microvascular decompression of the facial nerve with moving of the aneurysm resulted in complete relief of the hemifacial spasm. No enlargement of the aneurysm was shown on follow-up for a period of 6 years.
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Acta neurochirurgica · Aug 2005
Controlled Clinical TrialAnesthesia increases circulating glutamate in neurosurgical patients.
The excitotoxic amino acid glutamate is known to aggravate pre-existing neuropathology. Since volatile anesthetics increase plasma amino acid levels, we investigated if the anesthetics isoflurane and propofol increase plasma and cerebrospinal fluid (CSF) glutamate in neurosurgical patients. ⋯ The significant increases in plasma and CSF glutamate which were mostly sustained during isoflurane compared to propofol anesthesia should prompt the identification of anesthetic agents which do not impose a possible burden of glutamate-mediated excitotoxicity in patients with underlying compromised cerebral homeostasis. Detailed neuropsychological investigations following different anesthesia regimen are important to determine if transient elevations in CSF and plasma glutamate levels are of clinical relevance.
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Acta neurochirurgica · Aug 2005
Case ReportsExtracellular fluid S100B in the injured brain: a future surrogate marker of acute brain injury?
The authors describe the measurement of S100B protein in brain extracellular fluid (ECF) of patients with acute brain injury (traumatic brain injury and subarachnoid haemorrhage) using the technique of microdialysis. To our knowledge, this is the first report of S100B measurement in the human brain. Acute Brain Injury (ABI) is a leading cause of death and disability and the need for a practical and sensitive biochemical marker for monitoring these patients is urgent. ⋯ In this preliminary report of two cases, the authors demonstrate the quantification of S100B in ECF microdialysate, and investigate whether changes in hourly S100B profile can be related to secondary brain injury. It is shown that extracellular concentrations of S100B change markedly in response to secondary brain injury. Further investigation is required to determine whether extracellular S100B measurement in ABI could assist in patient management.
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Acta neurochirurgica · Aug 2005
Spectrin breakdown products in the cerebrospinal fluid in severe head injury--preliminary observations.
Calcium-induced proteolytic processes are considered key players in the progressive pathobiology of traumatic brain injury (TBI). Activation of calpain and caspases after TBI leads to the cleavage of cytoskeletal proteins such as non-erythroid alpha II-spectrin. Recent reports demonstrate that the levels of spectrin and spectrin breakdown products (SBDPs) are elevated in vitro after mechanical injury, in the cerebrospinal fluid (CSF) and brain tissue following experimental TBI, and in human brain tissue after TBI. ⋯ Elevation of calpain and caspase specific SBDPs is a significant finding in TBI patients indicating that intact brain spectrin- and SBDP-levels are closely associated with the specific neurochemical processes evoked by TBI. The results strongly support the potential utility of these surrogate markers in the clinical monitoring of patients with severe TBI and provide further evidence of the role of calcium-induced, calpain- and caspase-mediated structural proteolysis in TBI.