总结开颅术后严重脑脊液低容量（CCSFH）致脑疝患者的临床及影像学特点。

选取北京市顺义区医院神经外科自2019年1月至2023年11月收治的14例急性脑损伤开颅术后发生CCSFH致脑疝的患者，分析其临床资料、影像学特点、治疗过程及预后。采用改良Rankin量表（mRS）评估患者出院后6个月的预后。

CCSFH均发生于术后1~13 d。7例患者表现为意识或精神状态变差，其中3例发生瞳孔不等大；其余7例处于术后镇静镇痛状态，无法准确评估意识状态，瞳孔大小正常。CCSFH发生时中线移位（10.95±2.90）mm，范围为6.69~16.00 mm。5例患者的颅内压是1~11 mmHg（1 mmHg=0.133 kPa）。4例患者未能及时识别CCSFH，行去骨瓣减压术；10例患者采取平卧位、停止脑脊液引流等保守治疗。最终所有患者的CCSFH均得以逆转。随访6个月，mRS评分≤2分6例，mRS评分˃2分8例。

开颅术后CCSFH常表现为意识或精神状态变差，严重者出现小脑幕切迹疝，CT扫描显示中线明显移位，但颅内压呈相对低水平。平卧位是治疗CCSFH最主要的措施，辅以停止脑脊液引流和高渗利尿剂，给予静脉补液，可取得良好效果。

To investigate the clinical and imaging characteristics of patients with herniation secondary to critical cerebrospinal fluid hypovolemia (CCSFH) after craniotomy.

From January 2019 to November 2023, fourteen patients with acute brain injury were admitted to Neurosurgery Department of Beijing Shunyi District Hospital, and experienced cerebral herniation due to CCSFH after craniotomy. Their clinical and imaging characteristics, treatment course, and outcomes were analyzed. Prognosis at six months post-discharge was assessed with the modified Rankin scale (mRS).

CCSFH occurred within 1 to 13 d post-surgery. Seven patients exhibited a decline in consciousness or mental state, with three showing anisocoria. The remaining seven patients had regular pupil sizes, complicating consciousness assessment due to postoperative sedation and analgesia. The midline shift was (10.95±2.90) mm during the CCSFH presentation, ranging from 6.69 to 16.00 mm. Intracranial pressure ranged from 1-11 mmHg (1 mmHg=0.133 kPa) in 5 cases with CCSFH. Four cases underwent decompressive craniectomies owing to delayed CCSFH identification, while 10 cases received conservative treatment. The CCSFH condition was successfully reversed in all patients. Six months post-discharge, 6 cases had mRS scores≤2, and 8 had scores>2.

Post-craniotomy CCSFH often presents with deteriorating consciousness or mental status, and in severe cases, it may lead to transtentorial herniation. CT scans show significant midline shift, but the intracranial pressure remains relatively low. The primary treatment is positioning the patient supine, along with stopping cerebrospinal fluid drainage, halting use of hypertonic diuretics, and administering intravenous hydration, which often leads to good outcomes.