Gafen Noah, Sirotkin Igor, Pennington Amanda, Rea Brittany, Martinez Carlos R
University of Central Florida College of Medicine, Orlando.
Bay Pines Veteran Affairs Healthcare System, Florida.
Fed Pract. 2025 Jan;42(1):48-52a. doi: 10.12788/fp.0489. Epub 2025 Jun 18.
Arachnoid granulations are extensions of the subarachnoid space, an important component of the complex circulation of brain cerebrospinal fluid. While these structures primarily transmit cerebrospinal fluid into the dural venous sinuses, they also may serve as a conduit for brain tissue herniation. Such occurrences have been referred to in the literature as brain herniations into arachnoid granulations (BHAGs), which are considered incidental and asymptomatic but can be associated with nonspecific neurologic symptoms such as headache, tinnitus, vertigo, and seizure. BHAGs can be visualized more readily due to improved cross-sectional magnetic resonance imaging (MRI) with increased spatial and contrast resolution.
We present 5 cases where brain herniations were detected in patients undergoing MRI for various neurologic symptoms. All patients experienced chronic symptoms, including headaches and seizures. Two cases included BHAG in locations that were associated with the patients' symptoms.
BHAGs are increasingly recognized due to improved spatial resolution in MRIs. While there is still no definitive evidence that these lesions are responsible for various neurologic symptoms, some of these abnormalities may hold clinical significance, such as the visual symptoms seen in 2 of the cases described. BHAG can be associated with gliosis of adjacent brain tissue, which may be a mechanism for symptom development.
蛛网膜颗粒是蛛网膜下腔的延伸部分，是脑脑脊液复杂循环的重要组成部分。虽然这些结构主要将脑脊液输送到硬脑膜静脉窦，但它们也可能成为脑组织疝出的通道。文献中已提及此类情况为脑组织疝入蛛网膜颗粒（BHAGs），通常认为是偶然发生且无症状的，但可能与头痛、耳鸣、眩晕和癫痫发作等非特异性神经症状相关。由于具有更高空间和对比度分辨率的横断面磁共振成像（MRI）技术的改进，BHAGs更容易被观察到。
我们报告了5例在因各种神经症状接受MRI检查的患者中检测到脑组织疝出的病例。所有患者均有慢性症状，包括头痛和癫痫发作。其中2例的BHAG位于与患者症状相关的部位。
由于MRI空间分辨率的提高，BHAGs越来越受到关注。虽然目前仍没有确凿证据表明这些病变会导致各种神经症状，但其中一些异常情况可能具有临床意义，如在所描述的2例病例中出现的视觉症状。BHAG可能与相邻脑组织的胶质增生有关，这可能是症状产生的一种机制。
