Neurosurgical review
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Neurosurgical review · Jul 2013
ReviewDecompressive craniectomy and head injury: brain morphometry, ICP, cerebral hemodynamics, cerebral microvascular reactivity, and neurochemistry.
There has been renewed interest in decompressive craniectomy as a surgical treatment for elevated intracranial pressure (ICP), although evidence-based clinical data are still lacking and some experimental results are conflicting. Ongoing clinical trials on the use of this operation after traumatic brain injury (TBI) may clarify the clinical application of this technique, however, some pathophysiological issues, such as the timing of this operation, its effect on brain edema formation, and its role for secondary brain damage, are still controversial. This review addresses recent clinical data on the influence of decompressive craniectomy on the brain pathophysiology in TBI. ⋯ The gain in intracranial volume results in both the improvement of cerebral compliance and a decrease in ICP; the latter favors a rise in both cerebral blood flow and cerebral microvascular perfusion, which can be accompanied by elevation in brain tissue oxygen tension (PbtO2) as well as the return of abnormal metabolic parameters to normal values in cases of cerebral ischemia. Enhancement of edema formation, impairment of cerebrovascular pressure reactivity, and non-restoration of brain aerobic metabolism due to metabolic crisis may occur after craniectomy and require further investigations. This review suggests that decompressive craniectomy as the sole treatment is likely to be insufficient; efforts must be made to maintain adequate brain hemodynamics, preferably coupled with brain metabolism, in addition to treating brain metabolic abnormalities, during postoperative stages.
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Neurosurgical review · Jul 2013
Early seizures after clipping of unruptured aneurysms of the anterior circulation: analysis on consecutive 1,000 cases.
Seizures occurring after clipping of unruptured cerebral aneurysms have rarely been documented in the literature. The objective of this retrospective study is to clarify whether the frequency of early seizures, i.e., seizures occurring within 14 days of surgery, is influenced by patient- or aneurysm-specific characteristics. Data on 1,000 consecutive patients who underwent clipping of unruptured anterior circulation aneurysms were reviewed. ⋯ Patients with generalized seizures were significantly more likely to harbor an iatrogenic brain lesion than those with partial seizures (47 vs. 18 %; OR 4.148; 95 % CI 1.005-17.113). Among 40 patients with follow-up period >12 months, seizures were temporary without recurrence in 38 (95 %). Although early seizures are mostly benign, a small possibility of them becoming a permanent morbidity needs to be explained to patients undergoing elective clipping.
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Neurosurgical review · Jul 2013
Differences between middle cerebral artery bifurcations with normal anatomy and those with aneurysms.
The objectives of this study were to elucidate the normal anatomy of middle cerebral artery (MCA) bifurcations and to analyze the differences in patients with MCA aneurysms. In the present study, 62 patients underwent three-dimensional magnetic resonance angiography, and no intracranial lesions were noted. The widths of M1 and the superior and inferior M2 branches, as well as their respective lateral angles, were measured. ⋯ The DA ratio was 1.5 ± 0.4 in normal MCAs and 1.7 ± 0.7 in MCAs with aneurysms; this difference was significant (p < 0.05). The LA ratio was 1.3 ± 0.4 in normal MCAs and 2.1 ± 1.4 in MCAs with aneurysms; these values were also significantly different (p < 0.01). Normal cerebral artery bifurcations show close to symmetric structure in the M2 branches and the lateral angles, whereas aneurysmal MCAs do not show this symmetry.
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Neurosurgical review · Apr 2013
Association between elevated plasma norepinephrine levels and cardiac wall motion abnormality in poor-grade subarachnoid hemorrhage patients.
Patients with aneurysmal subarachnoid hemorrhage (SAH) are frequently complicated by acute cardiac dysfunctions, including cardiac wall motion abnormality (WMA). Massive release of catecholamine into the systemic circulation after aneurysmal rupture is believed to result in WMA, and poor-grade SAH seems to be the most important risk factor. However, plasma catecholamine levels have rarely been measured in SAH patients with WMA, and previous studies indicated that the elevated levels might not necessarily predict WMA. ⋯ Plasma norepinephrine levels were inversely correlated with left ventricular ejection fraction. Multivariate logistic regression analysis revealed that increased plasma norepinephrine levels were predictive of WMA, although age, female sex, and grade V SAH were not. This retrospective study highlights the role of norepinephrine in pathogenesis of SAH-induced WMA.
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Neurosurgical review · Apr 2013
The value of perfusion computed tomography in predicting clinically relevant vasospasm in patients with aneurysmal subarachnoid hemorrhage.
Delayed cerebral ischemia remains a severe potential complication of aneurysmal subarachnoid hemorrhage (SAH) possibly leading to death and disability. We evaluated a semiquantitative and visual analysis of perfusion computed tomography (PCT) as a predictor of clinically relevant vasospasm (CRV) in patients with aneurysmal SAH. Thirty-eight patients with aneurysmal SAH were analyzed yielding 145 PCT scans. ⋯ TTP is a sensitive and specific perfusion parameter in predicting CI in patients with SAH. Its use in the clinical setting may optimize the early treatment of patients at risk for vasospasm before the onset of clinical deterioration, especially when applying TCD as pretest. Further investigation in a larger patient population is required.