Electrical Stimulation for Cerebral Vasospasm After Subarachnoid Hemorrhage: A Systematic Review.

OBJECTIVES: Cerebral vasospasm is a severe and potentially lethal complication in patients with subarachnoid hemorrhage (SAH). Its pathogenesis is still not completely understood. The efficacy of current treatments, such as triple-H therapy or calcium channel blockers, is unsatisfactory, and a new therapy model would therefore be valuable. Electrical stimulation may have a considerable influence on cerebrovascular innervation. This systematic review gives an overview of the studies that have applied electrical stimulation in models of cerebral vasospasm. MATERIALS AND METHODS: We performed a systematic review of the literature, searching PubMed and Ovid Embase with the keywords "electric stimulation," "cerebral vasospasm," "subarachnoid hemorrhage," "sympathetic," and "parasympathetic." Additional papers were identified from the reference lists of the articles identified in the literature search. RESULTS: Increased cerebral blood flow (CBF) is a widely observed effect of spinal cord stimulation and sphenopalatine ganglion stimulation in models of physiological conditions or experimental cerebral vasospasm. Most studies were conducted in animals, 15 under physiological conditions and 11 in animals with SAH. Eight studies in humans were identified that examined the stimulation effect on CBF under physiological conditions. Only two studies looked at patients after SAH: one applied spinal cord stimulation (SCS) and the other transcutaneous electrical neurostimulation. Different mechanisms leading to stimulation-induced CBF increase that were discussed included "reversible functional sympathectomy," activation of brainstem vasomotor centers, involvement of central ascending pathways, release of neurohumoral factors, and interaction with sympathetic, parasympathetic, and trigeminal innervation. The results indicate that electrical stimulation is a promising procedure for prevention and treatment of cerebral vasospasm. CONCLUSION: Electrical stimulation, especially SCS and sphenopalatine ganglion stimulation, is a promising adjunct for existing therapies for vasospasm after SAH. Further experiments and prospective clinical studies are needed to establish its potential usefulness as a therapy or prevention option.

Efficacy of granulocyte colony stimulating factor in combination with erythropoiesis stimulating agents for treatment of anemia in patients with lower risk myelodysplastic syndromes: A systematic review.

Anemic patients with lower risk myelodysplastic syndromes are frequently treated with erythropoiesis stimulating agents (ESA), eventually in combination with granulocyte colony stimulating factor (G-CSF). However, the evidence for the efficacy of a combined treatment remains controversial. The goal of our analysis was to assess the available evidence for a combined treatment. We performed a systematic review and identified only nine eligible studies. In two randomized controlled trials (n = 98), erythroid response rates were 33% and 40% after low-/standard-doses of ESA alone (10,000-30,000 rHuEPO equivalents/week) versus 65% and 73% after combination treatment. In seven trials with sequential drug administration (n = 393), erythroid response rates ranged from 12% to 71% after full-doses of ESA alone (60,000-80,000 rHuEPO equivalents/week) and from 35% to 74% after combination therapy. Our analysis supports an additional efficacy of G-CSF added to low-/standard-dose ESA, but the available data remains controversial, if G-CSF is added to full-dose ESA.