Background Idiopathic intracranial hypertension (IIH) is a disorder of increased intracranial pressure without a clear cause and can have serious visual effects. Previous research work suggests that transcranial Doppler measurements of pulsatility index correlate accurately with elevated intracranial pressure. Objective To assess the cerebrovascular hemodynamic changes in patients with IIH using transcranial Doppler before and after lumbar puncture and CSF withdrawal. Methods An interventional study conducted on 40 patients (31 females and 9 males) fulfilling the modified Dandy criteria for diagnosis of idiopathic intracranial hypertension, MRI brain, and MRV was done to the patients. Lumbar puncture was done for all included patients to measure intracranial pressure and CSF withdrawal. Transcranial Doppler was performed for all included before and after lumbar puncture and CSF withdrawal and the following parameters were measured: peak systolic velocity (PSV), end diastolic velocity (EDV), resistivity index (RI), and pulsatility index (PI). Results Significant relation was found between grades of papilledema and PSV, RI, and PI ( p value 0.012, 0.025, 0.016) but no significant relation was found between grades of papilledema and EDV (0.102). Significant changes occurred in parameters of TCD pre- and post-CSF withdrawal including PSV, EDV, and PI ( p value 0.001, 0.015, 0.019) denoting a significant change in cerebral hemodynamics after CSF withdrawal which denotes a decrease in intracranial pressure. Conclusion Increased intracranial pressure significantly affects cerebral blood flow. A normalization of transcranial Doppler parameters occurs following lowering of intracranial pressure through lumbar puncture and CSF withdrawal.

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经颅多普勒对特发性颅内高压患者脑血管血流动力学的评价

背景 特发性颅内高压 (IIH) 是一种无明确原因的颅内压升高疾病，可产生严重的视觉影响。以前的研究工作表明，脉动指数的经颅多普勒测量与颅内压升高准确相关。目的应用经颅多普勒技术评估IIH患者腰椎穿刺和CSF停药前后脑血管血流动力学变化。方法对符合改良Dandy诊断特发性颅内高压标准的40例患者（女31例，男9例）进行介入研究，并对其进行脑MRI和MRV。对所有纳入的患者进行腰椎穿刺以测量颅内压和脑脊液回撤。对所有包括的腰椎穿刺和脑脊液撤除前后进行经颅多普勒，并测量以下参数：峰值收缩速度 (PSV)、舒张末期速度 (EDV)、电阻率指数 (RI) 和搏动指数 (PI)。结果 视乳头水肿分级与 PSV、RI 和 PI 之间存在显着相关性（p 值为 0.012、0.025、0.016），但在视乳头水肿分级与 EDV（0.102）之间未发现显着相关性。TCD 脑脊液停用前后参数发生显着变化，包括 PSV、EDV 和 PI（p 值 0.001、0.015、0.019），表明脑脊液停用后脑血流动力学发生显着变化，这表明颅内压降低。结论 颅内压增高对脑血流量有显着影响。