Large Arachnoid Cyst Research Articles

Intracranial Hemorrhagic Arachnoid Cyst: The Role of Diffusion-Weighted Imaging

The majority of hemorrhagic arachnoid cysts are correlated with trauma or aneurysmal rupture. We report on a 35-year-old woman with acute headache and an intracranial mass lesion that was hyperdense in CT and hyperintense in conventional MRI images. The history and imaging were negative for trauma or vascular anomaly. Diffusion-weighted imaging (DWI) clearly demonstrated a large right anterior and middle cranial fossa arachnoid cyst with associated subacute intracystic hemorrhage without subdural hematoma. DWI offers invaluable information for the differential diagnosis of hemorrhagic arachnoid cysts from other extra-axial space-occupying lesions.

Cervical anterior intradural arachnoid cyst in a child

Intradural arachnoid cysts involving the spine are uncommon and especially rare in an anterior cervical location. In the literature, among 15 patients, 8 were in the paediatric age group and in 3 patients the cyst was localised to the full length of the cervical spinal canal. Although they occur secondary to trauma, haemorrhage, surgery or inflammation, most of them are known to be idiopathic or congenital. Although the disease shows a dramatic neurological course, early diagnosis and treatment could provide good results. We report a 2(1/2) year-old boy with progressive tetraparesis with a huge anterior intradural arachnoid cyst located from the cervico-medullary junction to the C7 level. In the paediatric age group, cervical anterior intradural arachnoid cyst is an unusual cause of quadriparesis. The rarity of this condition and the relevance of MRI in the accurate and early diagnosis is discussed here. A 2(1/2) year-old boy with a large intradural arachnoid cyst extending from the cervico-medullary junction to C7 situated anteriorly is reported here; diagnosis and treatment modalities are discussed.

Asymptomatic Motor Cortex Displacement due to a Giant Arachnoid Cyst

Cerebral lesions are held to induce plastic changes of the brain. Less well established, however, is how much space-occupying brain lesions may only displace functional representations. In a 66-year-old man we show, by means of functional magnetic resonance imaging and transcranial magnetic stimulation, a profound displacement of the motor cortex due to a large asymptomatic arachnoid cyst. Thus, the chronically compressed brain is capable of sustaining normal brain function without utilizing the potential of cortical plasticity.

Efficacy of Preparticipation Brain CT Scan for Preventing Acute Brain Injuries in Amateur Kickboxers

Kickboxing is a full-contact sport using attacks with punches, kicks, and knee or elbow strikes to either the head or the body which may raise a concern for the similar risk of acute brain injury as boxing. PURPOSE: To evaluate the efficacy of brain CT scan as preparticipation medical examination of amateur kickboxing. METHODS: According to the statement in the rule of the All Japan University Kickboxing Federation, we had mandatorily performed brain CT scans in 1,136 consecutive collegiate students (1,128 males; age,19±1 years; almost all were Japanese) before competitively participating in amateur kickboxing from 1987 to 2007. Two neurosurgeons reviewed CT scans and determined the eligibility. We had not permitted participation in cases of cavum septum pellucida until 1999, but otherwise the criteria of judgment were not changed. RESULTS: Intracranial abnormalities were found in 76 cases (6.7%): cavum septum pellucida 32 (2.8%); megacisterna magna 26 (2.3%); arachnoid cyst 8 (0.7%); cavum vergae 5 (0.4%); porencephaly in the left frontal lobe 1 (0.09%); brain tumor 1 (0.09%); cerebral venous angioma 1 (0.09%); asymmetrical dilatation of the basal cistern 1 (0.09%); and mild dilatation of the subarachnoid space with cavum septum pellucida 1 (0.09%). Among the 76 cases, 19 were declined for participation and the reasons were as follows: cavum septum pellucida 10; large arachnoid cyst 3; megacisterna magna 2; brain tumor 1; cerebral venous angioma 1; asymmetrical dilatation of the basal cistern 1; mild dilatation of the subarachnoid space with cavum septum pellucida 1. During the 20 years of experience, one kickboxer with preparticipation brain CT scan being normal collapsed from acute subdural hematoma after a bout. The remaining 1,116 students (including megacisterna magna 24; cavum septum pellucida 22; small arachnoid cyst 5; cavum vergae 5; porencephaly in the left frontal lobe 1) had been able to competitively participate in kickboxing without any brain injury for 3 to 4 years while they engaged in full contact sparring regularly and in official kickboxing competitions several times in a year. CONCLUSIONS: Preparticipation brain CT scan could early recognize athletes with a possible risk of acute brain injury in amateur kickboxing. Still, it is not enough to prevent a tragic trauma completely in this discipline.

Case report: “Auditory neuropathy” in a newborn caused by a cerebellopontine angle arachnoid cyst

We present a 6-week-old girl, referred because of failed newborn hearing screening in the right ear. Click-evoked oto-acoustic emissions were present in both ears, auditory brainstem responses (ABR) were present in the left but totally absent in the right ear. A magnetic resonance imaging (MRI) study revealed a large arachnoid cyst in the right cerebellopontine angle (CPA) and a diagnosis of "auditory neuropathy/auditory dyssynchrony" was established. A microsurgical resection of the cyst wall and fenestration was performed by a retro sigmoid approach. This is the first case in the literature of auditory neuropathy (AN) in an infant caused by a cerebellopontine angle arachnoid cyst.

Novel Equine Collagen-only Dural Substitute

A watertight and meticulous dural closure is an essential step after intradural neurosurgical procedures. When such a task cannot be performed, dural replacement materials and other adjunctive measures can provide an effective barrier between the subarachnoid compartment and the extradural space. We present our experience with a novel collagen-derived dural substitute in a series of 114 patients undergoing a variety of neurosurgical procedures. The patients were clinically or neuroradiologically observed, for immediate and delayed local or systemic complications related to the implant. In three patients who underwent reoperation after decompressive duraplasty and craniectomy for bone flap repositioning, we performed biopsy of the dural implant for histopathological studies. None of the patients experienced local or systemic complications or toxicity related to the dural patch. None of the patients experienced a postoperative cerebrospinal fluid fistula, except one patient who underwent an endoscopic endonasal transsphenoidal marsupialization of a large intrasuprasellar arachnoid cyst; the fistula required reoperation for cerebrospinal fluid fistula repair and intravenous antibiotic therapy for bacterial meningitis. Postoperative magnetic resonance imaging scans showed signs of severe inflammatory response in only one patient who did not present any postoperative clinical symptom or neurological deficits. Three patients underwent reoperation for bone flap repositioning after decompressive craniectomy; in all patients, the dural substitute appeared to have promoted satisfactory dural regeneration, as confirmed by the histological studies. Furthermore, in such patients, no or minimal adherence with the other tissues and the brain cortex was observed. This study demonstrates that the new collagen-only biomatrix is a safe and effective dural substitute for routine neurosurgical procedures. The absence of local and systemic toxicity or complications and the scarce promotion of adherences and inflammation make this material appealing for its use as a dural substitute, even in cases in which the necessity of reoperation is foreseen.

Arachnoid cyst with growth hormone deficiency

On clinical grounds, arachnoid cysts are usually associated with neurological dysfunction. Little is known concerning their involvement in endocrine disorders. A seven-year-old boy was admitted to the hospital for evaluation of an unprovoked afebrile seizure. His neurological examination was normal, however, he had growth retardation. Insulin tolerance and L-dopa growth hormone stimulation tests revealed an inefficient growth hormone response. An MRI of hypophysis and cranium yielded a shift of hypophysis and a large arachnoid cyst.

Placement of subdural electrode grids for seizure focus localization in patients with a large arachnoid cyst

Subdural electrode arrays are placed to localize seizure foci for possible resection. The procedure is usually straightforward when an electrode grid array is placed on the brain convexity but can become complicated if the surface on which the grids are applied is not convex. Arachnoid cysts can be associated with seizures, but their topography presents a challenge to standard techniques for the placement of subdural grids. The authors report on a technique for electrode grid placement that successfully localized seizure foci in the depths of arachnoid cysts in two patients. Subdural grids were placed to conform to the concave cyst cavity. They were held in place with rolled gelatin foam padding, which filled the arachnoid cyst. The padding was removed before removing the electrode grids and resecting the seizure focus. Although arachnoid cysts present a technical challenge when seizure foci are located within the cyst cavity, the technique of packing the cyst cavity with gelatin foam provides good electrode contact on the concave cyst wall, allowing adequate seizure focus localization.

Spinal extradural arachnoid cysts: clinical, radiological, and surgical features

Extradural arachnoid cysts in the spine are rare and are seldom a cause of spinal cord compression. They are thought to arise from congenital defects in the dura mater, and they almost always communicate with the intrathecal subarachnoid space through a small defect in the dura. The mainstay of treatment in patients with neurological symptoms is surgical removal of the cyst together with ligation of the communicating pedicle and closure of the dural defect. In the present paper the authors review the literature and discuss the clinical and pathological features, mechanisms of pathogenesis, neuroimaging characteristics, and surgical management of spinal extradural arachnoid cysts. The surgical technique for removal of these lesions is illustrated in a patient with a large thoracolumbar spinal extradural arachnoid cyst causing neurogenic claudication.

Reversible Kernohan notch

A 55-year-old patient experienced episodic headaches, left facial twitching, and increasing falls over 2 years. Multiple yearly brain MRs (figure 1, top panels) revealed a large right frontal arachnoid cyst with evolving …

Teflon sponge shunt for recurrent arachnoid cyst

A 50-year-old female presented with complaints of progressive ataxia. Investigations showed a large intradural arachnoid cyst located anterior to the brainstem. Following marsupialization of the cyst she improved remarkably in her symptoms. The symptoms recurred nine months later and investigations revealed recurrence of the cyst. The cyst was evacuated again and two Teflon sponge sheets were placed such that they traversed the length of the cyst cavity and extended into the cisterna magna. At follow-up after 25 months, there has been no recurrence of symptoms or the cyst. The role and advantages of Teflon sponge in such cases is evaluated.

Two-step surgical treatment using miniature Ommaya’s reservoirs for a neonate with multiple large arachnoid cysts

We followed a two-step surgical strategy using miniature Ommaya's reservoirs in an early neonate with multiple large arachnoid cysts. Percutaneous fluid aspiration through the reservoirs placed during the first operation permitted the infant to develop sufficiently to withstand the second, more radical cyst wall excision.

A large arachnoid cyst of the lateral ventricle extending from the supracerebellar cistern—case report

Background The pathogenetic mechanism of intraventricular arachnoid cyst development is still controversial, but is believed to originate from the vascular mesenchyme or as an extension of the arachnoid cyst in the subarachnoid space into the ventricle through the choroidal fissure. We report a case supporting the extension hypothesis and suggest differential points between an intraventricular arachnoid cyst that extended from the supracerebellar space and a lateral ventricular diverticulum that extended into the supracerebellar cistern. Case Description A 12-month-old girl presented with macrocephaly and developmental delay. Her magnetic resonance imaging showed an arachnoid cyst that had developed from the supracerebellar space in the posterior fossa, and which extended into the left lateral ventricle resulting in expansion of the left lateral ventricle and displacing the choroids plexus anteriorly and laterally and the midline to the right. We treated an intraventricular arachnoid cyst by endoscopic fenestration resulting in dramatic reduction of the intraventricular arachnoid cyst with large bilateral subdural fluid collection. We performed a subduroperitoneal shunt for subdural fluid collection and subsequent cystoperitoneal shunt for the remnant cyst. Conclusion We suggest that this case supports the extension hypothesis from the subarachnoid space through the choroidal fissure into the lateral ventricle. We also suggest that one of the radiological differential points between an intraventricular arachnoid cyst and a ventricular diverticulum is displacement and compression of the choroid plexus of the lateral ventricle.

Somatomotor functional MRI in a hypertensive arachnoid cyst

In this article the authors report the study by functional MRI, before and after surgery, of the motor cerebral cortex surrounding a large hypertensive arachnoid cyst. They stress that the functional modifications due to surgery are more relevant than suggested by the simple morphological data.

Navigated laser-assisted endoscopic fenestration of a suprasellar arachnoid cyst in a 2-year-old child with bobble-head doll syndrome

The authors present the case of a 2-year-old boy with bobble-head doll syndrome (BHDS) associated with a large suprasellar arachnoid cyst and enlarged ventricles, who was successfully treated with neuronavigated laser-assisted endoscopic ventriculocystocisternostomy. The clinical history, surgical treatment, and clinical follow up of the patient are described. A navigated laser-assisted endoscopic ventriculocystocisternostomy of the suprasellar arachnoid cyst led to cessation of the head bobbing, and notable reduction of the cyst and ventricles was visible on the postoperative magnetic resonance images. Caused by a suprasellar arachnoid cyst, BHDS can be successfully treated with navigated laser-assisted endoscopic ventriculocystocisternostomy. The advantages of this procedure are minimal invasiveness and facilitated guidance of the neuronavigation system to the target area when normal anatomical landmarks are not visible.

Spinal Arachnoid Cyst Causing Paraplegia Following Skull Base Surgery-Case Report-

A 40-year-old woman presented with a right petroclival meningioma compressing the brainstem and manifesting as a 6-month history of headache and gait difficulty. The patient underwent subtotal removal of the tumor via an anterior transpetrosal approach. The postoperative course was complicated by cerebrospinal fluid rhinorrhea, bacterial meningitis, and acute hemorrhagic rectal ulcer. The patient was discharged home in good condition after prolonged medical treatment. Four months after the surgery, the patient noted recurrence of gait difficulty. Magnetic resonance (MR) imaging of the brain showed enlargement of the ventricles and no residual brainstem compression. A ventriculoperitoneal shunt was placed, but the symptoms were unchanged. The shunt was removed 2 months later because of infection. The patient's gait gradually deteriorated, although repeat brain MR imaging showed no significant increase in ventricular size. Ten months after the initial surgery she became paraplegic. MR imaging of the thoracic spine revealed a large arachnoid cyst extending from C-6 to T-6. The patient underwent T2-4 laminectomy, partial removal of the cyst wall, and duraplasty, but no clinical improvement was observed. Preexisting long-tract signs and coincidental hydrocephalus confused the neurological findings and delayed detection of the spinal lesion in this case. Neurosurgeons should be alert to the possibilities of insidious spinal lesion if the patient has progressive neurological disorder which does not match the known cranial lesion.

Helmetlike skull deformity with a large arachnoid cyst

Background It is not difficult to find localized skull ballooning or macrocrania in patients with intracranial arachnoid cysts. However, there have been no previous reports regarding large localized skull protuberant deformities resembling a war helmet. The authors report with a review of literature a case of an adult with helmetlike skull deformity resulting from a large supratentorial arachnoid cyst. Case Description A 35-year-old man presented with a large head deformity since his early childhood that had been the result of gradual progression from infantile macrocrania. He also had mental retardation, sixth cranial nerve palsy with recent aggravation of headache, reduced activity, poor voiding control, and walking disturbance. Magnetic resonance imaging of the head showed hydrocephalus with a large supratentorial arachnoid cyst located in the bilateral parietooccipital area compressing the hemisphere anteriorly, and the tentorium and cerebellum inferiorly. Magnetic resonance venogram demonstrated low-lying short transverse and lateral sinuses, and the superior sagittal sinus and falx were displaced to the right side. Radioisotopic cisternogram showed nonfilling of the isotope in the bilateral parietooccipital area. Cerebrospinal fluid pressure measured by lumbar puncture was 17 cm H 2O. We tentatively diagnosed the condition as normopressure hydrocephalus with a large supratentorial arachnoid cyst. His headache, reduced activity, poor voiding control, and walking disturbance improved after a cystoperitoneal shunt. Conclusions This might suggest that large arachnoid cysts found in childhood should be treated for prevention of skull deformity and late aggravation of increased intracranial pressure.

Extradural spinal arachnoid cysts associated with spina bifida occulta

Spinal extradural arachnoid cysts are an uncommon cause of neural compression in children. Even more uncommon is the association of such cysts with spina bifida occulta. Two girls, 12 and 8-years-old, presented with left leg pain, deteriorating gait, clinical signs of left L5 and S1 root compression, without bladder or bowel symptoms. The first patient had left foot drop. The second patient had muscle wasting and smaller left foot with pes cavus. Radiographs showed spina bifida occulta of S1 in both. MRI revealed an extradural cyst at the S1 level, indenting the thecal sac and the L5 and S1 roots. At operation in both patients a large arachnoid cyst arising from a small dural defect in the axilla of the left S1 root was compressing and displacing it and the dural sac. It was removed and the defect was repaired. The first patient improved with complete recovery of the foot drop. An MRI at 12 months showed no cyst recurrence. The second patient made good recovery initially, but at 10 months developed recurrent symptoms. An MRI scan showed recurrence of the cyst with root compression. On repeat exploration a different dural defect was identified in a more anterior position and was repaired. The coexistence of extradural arachnoid cyst and corresponding bifid spinal segment has not been described previously. It raises the suspicion that the dural defect giving rise to the arachnoid cyst may be due to segmental dural dysgenesis in the context of the dysrhaphic neuroectodermal malformation.

Arachnoid cyst resulting in tonsillar herniation and syringomyelia in a patient with achondroplasia

Achondroplasia has been associated with varying degrees of cervicomedullary and spinal compression, although usually in the pediatric population. Large arachnoid cysts have also been found to result in tonsillar herniation and syringomyelia. The authors present the case of a patient with achondroplasia who presented with symptoms of foramen magnum compression and syringomyelia, and who was subsequently found to have a large posterior fossa arachnoid cyst. This 38-year-old woman with achondroplasia presented with an 8-month history of headache and numbness of the hands and fingers. Admission magnetic resonance (MR) imaging of the head and spine revealed a large arachnoid cyst in the posterior cranial fossa, a 6-mm tonsillar herniation consistent with an acquired Chiari malformation, and a large cervicothoracic syrinx. The patient was treated using suboccipital craniectomy, C-1 laminectomy, fenestration of the arachnoid cyst, and decompression of the acquired Chiari malformation with duraplasty. Surgical decompression resulted in improvement of the presenting symptoms, adequate decompression of crowding at the foramen magnum, and resolution of the syrinx. Although there was only partial reduction in the retrocerebellar cisternal space on follow-up MR imaging, no residual symptoms were related to this.

Noncommunicating spinal extradural arachnoid cyst causing spinal cord compression in a child

Extradural arachnoid cysts in the spine are relatively uncommon causes of spinal cord compression in the pediatric population that are thought to arise from congenital defects in the dura mater. Most reports describe such cysts communicating with the intrathecal subarachnoid space through a small defect in the dura. The authors describe the case of a child who presented with spinal cord compression caused by a large spinal extradural arachnoid cyst that did not communicate with the intradural subarachnoid space. An 11-year-old girl presented with urinary urgency, progressive lower-extremity weakness, myelopathy, and severe gait ataxia. Magnetic resonance imaging of the spine demonstrated a large extradural arachnoid cyst extending from T-8 to T-12. The patient underwent a thoracic laminoplasty for en bloc resection of the spinal extradural arachnoid cyst. Intraoperatively, the dura was intact and there was no evidence of communication into the intradural subarachnoid space. Postoperatively, the patient's motor strength and ambulation improved immediately, and no subsequent cerebrospinal fluid leak occurred. Noncommunicating spinal extradural arachnoid cysts are extremely rare lesions that can cause spinal cord compression in children. Because the dura remains intact, they can be removed entirely without subsequent dural repair. The authors review the literature and discuss the proposed underlying mechanisms of formation of these arachnoid cysts.