• Journal of Korean Neurosurgical Society
• /
• v.65 no.4
• /
• pp.591-597
• /
• 2022

Objective : Pituitary adenomas frequently extend into the suprasellar space. After a suprasellar tumor is removed, the superiorly extended arachnoid becomes redundant and sinks down into the intrasellar space which often hiders visualization and accessibility to the hidden space behind the evaginated arachnoid. We introduced arachnoid remodeling by clipping technique, and evaluated its usefulness and safety during TSS. Methods : Total 223 patients who underwent arachnoid remodeling with our new clipping technique were included. Redundant arachnoid was clipped along the dural edge with multiple 2.6-mm titanium clips until the redundant arachnoid membrane no longer blocked the surgical route. To check for possible deterioration of hormonal function by this technique, we assessed anterior pituitary function of 166 patients who underwent arachnoid remodeling by clipping and compared this with those of other 429 control patients. Results : Our technique greatly enhanced the accessibility and visualization of intrasellar and parasellar spaces, both of which are generally hindered by redundant arachnoid during transsphenoidal surgery (TSS). We found no difference in anterior pituitary function between a clip-assisted arachnoid remodeling group and the control group, implying that this technique does not result in hypopituitarism. Conclusion : During TSS for pituitary adenomas with suprasellar extension, arachnoid remodeling by clipping technique is very useful and convenient for the management of the redundant arachnoid membrane to enhance visualization and surgical accessibility.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.sup2
• /
• pp.340-343
• /
• 2001

Arachnoid cysts are defined as duplicated arachnoids and their splitting with congenital, intra-arachnoid, and leptomeningeal malformations. They are most commonly located in the middle cranial fossa followed by suprasellar and quadrigeminal cisterns, posterior fossa, and very rare in cerebral convexities. They are often ruptured by trauma or spontaneously and cause subdural hygroma or subdural hematoma. Authors report a case of a 32-year-old woman with a convexity arachnoid cyst mimicking subdural hygroma associated with a separate middle fossa arachnoid cyst. Preoperatively, the convexity arachnoid cyst was misinterpreted as subdural hygroma resulted from a ruptured middle fossa cyst. The patient underwent craniotomy and cyst fenestration into the basal cistern. Two separate arachnoid cysts were found in the cerebral convexity and middle cranial fossa during the operation. Finally, cysts were resolved and she was discharged without any complication.

• Investigative Magnetic Resonance Imaging
• /
• v.25 no.1
• /
• pp.43-46
• /
• 2021

Arachnoid cysts are benign lesions that are formed between the inner and outer layers of the arachnoid, accounting for 1% of all intracranial space occupying lesions. Usually, arachnoid cysts are asymptomatic. It can be symptomatic in case of complication such as intracystic hemorrhage or acute cyst expansion. We present a case of incidentally prediagnosed arachnoid cyst which undergone intracystic hemorrhage combined with ipsilateral SDH in a young male.

• Journal of Korean Neurosurgical Society
• /
• v.45 no.5
• /
• pp.315-317
• /
• 2009

While syringomyelia is not a rare spinal disorder, syringomyelia associated with a spinal arachnoid cyst is very unusual. Here, we report a 62-year-old man who suffered from gait disturbance and numbness of bilateral lower extremities. Spinal magnetic resonance imaging (MRI) showed the presence of a spinal arachnoid cyst between the 7th cervical and 3rd thoracic vertebral segment and syringomyelia extending between the 6th cervical and 1st thoracic vertebral segment. The cyst had compressed the spinal cord anteriorly. Syringomyelia usually results from lesions that partially obstruct cerebrospinal fluid flow. Therefore, we concluded that the spinal arachnoid cyst was causing the syringomyelia. After simple excision of the arachnoid cyst, the symptoms were relieved. A follow-up MRI demonstrated that the syringomyelia had significantly decreased in size after removal of the arachnoid cyst. This report presents an unusual case of gait disturbance caused by syringomyelia associated with a spinal arachnoid cyst.

• Journal of Korean Neurosurgical Society
• /
• v.64 no.1
• /
• pp.110-119
• /
• 2021

Objective : Preoperative prediction of the arachnoid membrane descent in pituitary surgery is useful for achieving gross total removal and avoiding cerebrospinal fluid leakage resulting from tearing of the arachnoid membrane in the chiasmatic cistern. In this study, we analyzed the patterns of arachnoid membrane descent during or after pituitary tumor surgery and identified the factors related to this descent. Methods : Analysis was restricted to pituitary macroadenomas not extending into the third ventricle or over the internal carotid artery. To minimize confounding factors, patients who underwent revision surgery, those who had a torn arachnoid during operation or small medial diaphragma sellae (DS) opening, and subtotal resections were excluded. We enrolled 41 consecutive patients in this retrospective analysis. The degree of arachnoid descent was categorized using intraoperative videos. Preoperative magnetic resonance findings, including tumor height, suprasellar extension, and variables including DS area and medial opening size, tumor composition, and displacement of the pituitary stalk and gland were evaluated to determine their correlations with arachnoid membrane descent. Results : Arachnoid membrane descent was significantly correlated with DS area and medial opening size. Based on T2-weighted images (T2WI) magnetic resonance (MR) images, tumor composition was significantly associated with arachnoid membrane descent. Other factors were not significantly correlated with arachnoid membrane descent. Conclusion : T2WI of tumor composition and preoperative MR imaging of DS area and medial opening provided valuable information regarding arachnoid membrane descent. These parameters may serve as fundamental measures to facilitate complete resection of pituitary macroadenomas.

• Journal of Korean Neurosurgical Society
• /
• v.59 no.3
• /
• pp.314-318
• /
• 2016

Posterior fossa is a site next to the middle fossa where arachnoid cyst frequently occurs. Generally, most arachnoid cysts are asymptomatic and are found incidentally in most cases. Although arachnoid cysts are benign and asymptomatic lesions, patients with posterior fossa arachnoid cysts often complain of headaches, gait disturbance, and ataxia due to the local mass effects on the cerebellum. We observed a patient with a posterior fossa arachnoid cyst who had visual symptoms and a headache, but did not have gait disturbance and ataxia. We recommended an emergency operation for decompression, but the patient refused for personal reasons. After 7 days, the patient revisited our hospital in a state of near-blindness. We suspected that the arachnoid cyst induced the hydrocephalus and thereby the enlarged third ventricle directly compressed optic nerves. Compressed optic nerves were rapidly aggravated during the critical seven days; consequently, the patient's vision was damaged despite the operation. Considering the results of our case, it is important to keep in mind that the aggravation of symptoms cannot be predicted; therefore, symptomatic arachnoid cysts should be treated without undue delay.

• Journal of Korean Neurosurgical Society
• /
• v.52 no.3
• /
• pp.257-260
• /
• 2012

Spinal extradural arachnoid cysts usually cause symptoms related to spinal cord or nerve root compression. Here, we report an atypical presentation of a spinal extradural arachnoid cyst combined with congenital hemivertebra which was presented as a retroperitoneal mass that exerted mass effects to the abdominal organs. On image studies, the communication between the cystic pedicle and the spinal arachnoid space was indistinct. Based on our experience and the literature of the pathogenesis, we planned anterior approach for removal of the arachnoid cyst in order to focus on mass removal rather than ligation of the fistulous channel. In our estimation this was feasible considering radiologic findings and also essential for the symptom relief. The cyst was totally removed with the clogged 'thecal sac-side' end of the cystic pedicle. The patient was free of abdominal discomfort by one month after the surgery.

• Journal of Korean Neurosurgical Society
• /
• v.40 no.2
• /
• pp.69-73
• /
• 2006

Objective : The optimal surgical treatment for symptomatic middle cranial fossa arachnoid cysts is controversial. Therapeutic options include endoscopic fenestration, excision, cyst shunting, and craniotomy for fenestration of basal cistern. We reviewed the results of surgically treated middle cranial fossa arachnoid cysts. Methods : We performed a retrospective study in 18 cases of middle cranial fossa arachnoid cysts who had been treated with microsurgical fenestration between 1995 to 2003. The analysis was based on the results of the patients' age, sex distribution, developed area, clinical symptoms, treatment method, and complications. Results : Eighteen surgical treated middle cranial fossa arachnoid cysts patients were evaluated. The age range of cyst development was between 2 years and 44 years with the average of 16.4 years. The follow-up periods averaged 31.48 months. There were 15 male and 3 female patients, with significantly more cyst development in males than females. The most common clinical symptom was headache, followed by seizure. In the entire series, 77.8% of patients demonstrated a decrease in cyst size In serial imaging studies. Of them, 67.3% demonstrated a complete cyst effacement. Overall, 100% of patients with Grade I cysts, 81.8% of patients with Grade II cysts, 60% of patients with Grade III cysts exhibited evidence of decrease in cyst size during long-term monitoring. Complications included headache, meningitis, and hydrocephalus. Conclusion : Patients who were treated with microsurgical fenestration showed good outcome with acceptable complications. We concluded that microsurgical fenestration is a safe and effective surgical method for middle cranial fossa arachnoid cysts.

• Journal of Veterinary Clinics
• /
• v.23 no.3
• /
• pp.366-370
• /
• 2006

Arachnoid cysts are intra-arachnoid collections of cerebrospinal fluid. They may cause neurological deficit through expansion that can compress normal neural tissue and obstruct cerebrospinal fluid flow. Intracranial arachnoid cysts were found in 4 patients aged 10 months to 20 months(mean age 15 months). The presenting symptoms included circling(dog 2,3), seizure(dog 1), progressive weakness(dog 1,2,3), increasing scoliosis(dog 3), worsening spasticity(dog 3), and salivation(dog 3). One patient showed no symptoms from the intracranial arachnoid cyst. There were no significant findings in complete blood count and serum chemistry. Computed tomography(CT) with/without magnetic resonance imaging(MRI) scans were performed in these cases. Hypodense intracranial arachnoid cyst was observed on CT images in dog 4. Sagittal T1-weighted(T1W) and T2-weighted(T2W) images and transverse T1W and T2W images revealed a intracranial arachnoid cysts with syringohydromyelia(dog 3) and hydrocephalus(dog 3,4) in the brain. Clinical signs of three cases were improved by medication.

• Investigative Magnetic Resonance Imaging
• /
• v.21 no.3
• /
• pp.183-186
• /
• 2017

A 7-year-old boy, diagnosed with an arachnoid cyst and subdural effusion on initial MRI, was admitted with left limb weakness and no history of head trauma. A subsequent follow-up MRI showed different stages of hematoma within multilayered enhancing membranes and in the arachnoid cyst, which was separated by the cerebrospinal fluid cleft. Craniotomy and fenestration of the cyst wall and hematoma removal were performed. The patient was diagnosed as a having a hemorrhagic rupture of an arachnoid cyst into the intradural space, probably via some one-way valve-like defect, based on the MRI and surgical findings. The MRI features and possible mechanism of this rare disease are discussed within the literature review.