Al Shammas Nabil, Luck Robert, Schumann Sophie, Köhler Dragana, Mirow Lutz, Rosengarten Bernhard
Department of Neurology, Chemnitz Medical Center, Flemmingstraße 2, 09116, Chemnitz, Germany.
Department of General and Visceral Surgery, Chemnitz Medical Center, Campus of the Medical Faculty of the Technical University Dresden, Flemmingstraße 2, 09116, Chemnitz, Germany.
Ultrasound J. 2025 Jul 28;17(1):35. doi: 10.1186/s13089-025-00439-z.
Increase in body mass index (BMI) is a risk factor for idiopathic intracranial hypertension (IIH). The matter of body weight and intracranial pressure (ICP) in clinically asymptomatic obese patients is unknown. We aimed at studying the relationship of ICP and BMI pre- and post-surgery in obese patients undergoing bariatric surgery.
Patients with a BMI > 35 kg/m, qualified for bariatric surgery and without clinical signs of IIH were prospectively and consecutively included. The optic nerve sheath diameter (ONSD) and a combined transcranial Doppler-arterial blood pressure (TCD&ABP-ICP) method were used to non-invasively determine the ICP (nICP) pre- and post-surgery (six months after surgery when weight loss had stabilized). ONSD > 5.8 mm and nICP > 25cmHO were assumed as pathologically increased. A nICP between > 20 and ≤ 25 cmH2O was assumed as being in the borderline.
54 patients (43 female; 44 ± 11 years old) were included. Pre-surgery BMI (46 ± 6 kg/m) significantly declined after surgery (post-surgery BMI: 32 ± 6 kg/m2; paired t-test: p < 0.0001). Initial ONSD was 5.8 ± 0.6 mm (6 pathological values) which declined to 5.4 ± 0.6 mm (5 pathological values) (paired t-test: p < 0.025). TCD&ABP assessed nICP was 19 ± 4.5 cmHO (5 with pathological, 16 with borderline values) pre-surgically and declined to 14 ± 4 cmHO (no pathological, 1 high-normal value) after surgery (p < 0.0001).
Assuming the low incidence of IIH, the frequency of pathologic and borderline ICP values in obese patients was unexpectedly high. Reduction of ICP with weight loss followed a simple regression line pointing to a mechanistic effect of increased body weight on ICP. The constancy of pathologic ONSD values might be due to a fixed dilatation of the optic nerve sheath due to the duration of obesity.
体重指数（BMI）增加是特发性颅内高压（IIH）的一个危险因素。临床上无症状肥胖患者的体重与颅内压（ICP）之间的关系尚不清楚。我们旨在研究接受减肥手术的肥胖患者术前和术后ICP与BMI的关系。
前瞻性连续纳入BMI>35kg/m²、符合减肥手术条件且无IIH临床症状的患者。采用视神经鞘直径（ONSD）和经颅多普勒-动脉血压联合（TCD&ABP-ICP）方法在术前和术后（体重减轻稳定后的术后6个月）无创测定ICP（nICP）。ONSD>5.8mm和nICP>25cmH₂O被认为病理性升高。nICP在>20至≤25cmH₂O之间被认为处于临界值。
纳入54例患者（43例女性；44±11岁）。术前BMI（46±6kg/m²）术后显著下降（术后BMI：32±6kg/m²；配对t检验：p<0.0001）。初始ONSD为5.8±0.6mm（6个病理值），降至5.4±0.6mm（5个病理值）（配对t检验：p<0.025）。术前TCD&ABP评估的nICP为19±4.5cmH₂O（5个病理值，16个临界值），术后降至14±4cmH₂O（无病理值，1个高正常值）（p<0.0001）。
假设IIH发病率较低，肥胖患者病理性和临界ICP值的频率出乎意料地高。随着体重减轻ICP降低遵循一条简单的回归线，表明体重增加对ICP有机械作用。病理性ONSD值的恒定可能是由于肥胖持续时间导致视神经鞘的固定扩张。
