Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2013
ReviewSpreading ischemia after aneurysmal subarachnoid hemorrhage.
Spreading depolarization (SD) is a wave of mass neuronal and glial depolarization associated with net influx of cations and water. Prolonged SDs facilitate neuronal death. SD induces tone alterations in cerebral resistance arterioles, leading to either transient hyperperfusion (physiological neurovascular coupling) in healthy tissue or hypoperfusion (inverse neurovascular coupling = spreading ischemia) in tissue at risk for progressive damage. ⋯ In animals, spreading ischemia produced widespread cortical necrosis. In patients, spreading ischemia occurred in temporal correlation with ischemic lesion development early and late after aSAH. We briefly review important features of SD and spreading ischemia following aSAH.
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Acta Neurochir. Suppl. · Jan 2013
Randomized Controlled Trial Multicenter StudyDevelopment of nicardipine prolonged-release implants after clipping for preventing cerebral vasospasm: from laboratory to clinical trial.
We have developed a drug delivery system using a vasodilating drug that can be implanted intracranially at the time of surgery for aneurysm clipping, without systemic side effects or side effects associated with long-term intrathecal drug administration. We started our project on 1994 for making a slowly releasing drug delivery system in vitro because cerebral vasospasm occurs 4-14 days following subarachnoid hemorrhage (SAH). A rod-shaped pellet containing 1 mg of nicardipine for animal study was prepared by heat compression. ⋯ Vasospasm was completely prevented in the arteries by placing NPRIs adjacent to the arteries during surgery. No complications were experienced. We have performed three studies (a single-center study with consecutive patients; a single-center, randomized, double-blind trial; and a multicenter cooperative study) and have proved that implantation of NPRIs reduces the incidence of cerebral vasospasm and DINDs and improves clinical outcome after SAH.
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Acta Neurochir. Suppl. · Jan 2013
ReviewEndovascular management of posthemorrhagic cerebral vasospasm: indications, technical nuances, and results.
Posthemorrhagic cerebral vasospasm (PHCV) is a common problem and a significant cause of mortality and permanent disability following aneurysmal subarachnoid hemorrhage. While medical therapy remains the mainstay of prevention against PHCV and the first-line treatment for symptomatic patients, endovascular options should not be delayed in medically refractory cases. Although both transluminal balloon angioplasty (TBA) and intra-arterial vasodilator therapy (IAVT) can be effective in relieving proximal symptomatic PHCV, only IAVT is a viable treatment option for distal vasospasm. ⋯ Conversely, IAVT is generally considered an effective and low-risk procedure, despite the transient nature of its therapeutic effects and the risk of intracranial hypertension associated with its use. Moreover, newer vasodilator agents appear to have a longer duration of action and a much better safety profile than papaverine, which is rarely used in current clinical practice. Although endovascular treatment of PHCV has been reported to be effective in clinical series, whether it ultimately improves patient outcomes has yet to be demonstrated in a randomized controlled trial.
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Acta Neurochir. Suppl. · Jan 2013
Deep brain stimulation of the ventrolateral thalamic base and posterior subthalamic area in dystonic head tremor.
Dystonic head tremor (DHT) is characterized by head tremor associated with cervical dystonia (CD). Deep brain stimulation (DBS) can be considered when local treatment with botulinum toxin or oral medication has failed. However, there is lack of data regarding the optimal target structure for surgery in DHT. ⋯ Based on these observations, we performed DBS in three patients with DHT, placing the proximal contacts of the electrodes into the inferior base of VL thalamic nuclei and the distal contacts into the adjacent PSA. Chronic stimulation improved not only head tremor but also CD. These findings suggest that DBS at the base of VL thalamus and the adjacent PSA should undergo further investigation as a potential target for patients with DHT.