Introduction: Chiari malformation type I (CMI) is a congenital anomaly characterized by the descent of the cerebellar tonsils into the foramen magnum (FM), leading to cerebrospinal fluid circulation disturbances at the level of the posterior cranial fossa (PCF) and the craniovertebral junction (CVJ). Headache (HA) is the predominant symptom, often mimicking primary cephalalgias, complicating diagnosis and optimal surgical strategy selection.

Aim of the study: To analyze the characteristics of headache in CMI, identify the pathophysiological mechanisms of typical (tHA) and atypical headaches (aHA), and assess the effectiveness of different decompressive surgical techniques in postoperative pain relief.

Materials and methods: The study included 102 patients (58 females, 44 males, aged 2-69) with isolated or complicated CMI who underwent decompressive surgery at the Neurosurgery Department of Azerbaijan Medical University and the Republican Neurosurgical Center (2016-2024). Patients were divided into two groups based on headache type: typical HA (tHA, n=82) and atypical HA (aHA, n=20). Headache characteristics and dynamics were assessed using neurological and neuroimaging monitoring.

Results: Decompression surgery significantly reduced headache severity, particularly in tHA patients. The best outcomes for aHA patients were observed with intra-arachnoid dissection and duraplasty.

Conclusion: The findings can contribute to optimizing surgical approaches for CMI treatment.

简介： Chiari I畸形（CMI）是一种先天性异常，其特点是小脑扁桃体下移至枕骨大孔（FM），导致后颅窝（PCF）和颅颈交界处（CVJ）的脑脊液循环障碍。头痛（HA）是最常见的症状，常常类似原发性头痛，这使得诊断和选择最佳手术策略变得复杂。

研究目的： 分析CMI患者的头痛特点，识别典型头痛（tHA）和非典型头痛（aHA）的病理生理机制，并评估不同减压手术技术在术后止痛效果中的有效性。

材料与方法： 本研究包括了102名患者（58名女性，44名男性，年龄范围为2至69岁），他们在阿塞拜疆医科大学神经外科和共和国内科手术中心接受了孤立性或复杂的CMI减压手术（2016-2024年）。根据头痛类型将患者分为两组：典型HA (tHA, n=82) 和非典型HA (aHA, n=20)。通过神经学和神经影像监测评估头痛特征及动态变化。

结果： 减压手术显著减轻了患者的头痛严重程度，特别是对于tHA患者效果更佳。而对于aHA患者，脑池内蛛网膜分离术和硬脑膜修补术显示出最佳疗效。

结论： 研究发现有助于优化CMI治疗的外科方法。