111/469. Giant anterior cervicothoracic arachnoid cyst. STUDY DESIGN: A case report with a review of the literature is presented demonstrating the imaging findings of a patient with recent onset, progressive spinal cord compression at T6 caused by a giant arachnoid cyst that was successfully treated. OBJECTIVE: To present the imaging findings of a giant anterior cervicothoracic intradural arachnoid cyst using several methods before and after treatment. SUMMARY OF BACKGROUND DATA: This case demonstrates the imaging findings of the largest described anterior cervical arachnoid cyst straddling the cervicothoracic junction. It presented with spinal cord compression in a 26-year-old diagnosed by MRI and successfully treated surgically. methods: The patient experienced progressive left-sided sensory and motor deficits below T6. pain and temperature sensation were decreased. Reflexes were increased in both lower extremities with clonus. Preoperative MRI was followed by laminectomy and cyst fenestration with subsequent postoperative myelogram and CT. RESULTS: Imaging confirmed the presence of a giant arachnoid cyst straddling the cervicothoracic junction. Postoperative imaging documented relief of spinal cord compression. Symptoms improved progressively after surgery. By the time of discharge all residual neurologic deficits had resolved. CONCLUSION: Anterior arachnoid cysts straddling the cervicothoracic junction have yet to be reported, and arachnoid cysts involving the cervical region are extremely rare. Imaging demonstrated the cyst and its response to treatment. This patient responded well to surgery and was discharged without neurologic sequelae. ( info) |
112/469. Arachnoid cyst of the fallopian canal: a surgical challenge. OBJECTIVE: Spontaneous cerebrospinal fluid (CSF) leaks from the fallopian canal are exceedingly rare, with only 6 reports appearing in the world literature. We report a seventh case that is unique in that it involves an arachnoid cyst of the fallopian canal and an associated facial nerve palsy. STUDY DESIGN: Case report. SETTING: International tertiary care referral center. CONCLUSION: CSF otorhinorrhea associated with a facial nerve palsy may be indicative of an arachnoid cyst of the fallopian canal. These fistula are extremely rare. Surgical management involves sealing the fistula while preserving facial nerve function and is extremely challenging. ( info) |
113/469. Spontaneous resolution of a prepontine arachnoid cyst. Case report and review of the literature. Prepontine arachnoid cysts are rare developmental anomalies that occur almost exclusively in children. The symptomatic child typically suffers from hydrocephalus, visual impairment, endocrine dysfunction and/or cranial neuropathies. Some cysts, however, are discovered incidentally upon prenatal or postnatal imaging for other indications. While there is little doubt that surgical treatment should be initiated to help the symptomatic child, appropriate therapy for the asymptomatic patient is unclear. Although arachnoid cysts are often managed conservatively using serial imaging, the consequences of injury to surrounding structures with prepontine cysts often lowers the threshold for intervention. The natural history of asymptomatic prepontine arachnoid cysts is unknown. It has been reported that some cysts enlarge and cause symptoms, whereas others are stable for years. This report describes an index case of spontaneous resolution of a prepontine arachnoid cyst in a female infant over a 5-year period. ( info) |
114/469. Petrous apex arachnoid cyst extending into Meckel's cave. A rare case of arachnoid cyst involving the petrous apex with an unusual clinical presentation has been described with special emphasis in the imaging features and importance of accurate presurgical diagnosis. Differentiation from the other benign lesions involving the petrous apex and the role of newer MR techniques in the diagnosis of these lesions has been highlighted. ( info) |
115/469. Post-traumatic intradiploic leptomeningeal fistula and cyst. A 59 year old female patient presented with ataxia and difficulty in walking. The neurological examination revealed right homonymous hemianopia and ataxia. Radiographic evaluation revealed a large occipital intradiploic cyst mainly in the left suboccipital area. There was also moderate hydrocephalus and encephalomalacia of the left occipital pole. Bone window studies also demonstrated a growing fracture extending from the upper pole of the cyst to the vertex. Both pathologies were attributed to child abuse the patient suffered when she was a child. At first surgery, decompression of the cerebellum was followed by duroplasty and acrylic cranioplasty to the posterior cranial fossa. A month later, a shunt had to be inserted for hydrocephalus. At 7 months postoperatively, the patient is well and free of any symptoms or recurrence. ( info) |
116/469. Chronic subdural hemorrhage into a giant arachnoidal cyst (Galassi classification type III). The authors present CT and MRI of a patient with an extremely large arachnoidal cyst (Galassi classification type III). The cyst extended from the base of the skull, posterior to the brain stem, on the base of the temporal lobe over the complete convexity of the left hemisphere. The cyst consisted of multiple compartments with intracystic septa and was accompanied by a chronic subdural hemorrhage in the compartments. After contrast agent application, the typical characteristics of chronic subdural membranes were found. Besides bony deformities, a thinning of the inner table was found. The patient underwent craniotomy for evacuation of the hemorrhage and fenestration of the septa while he was free of symptoms. This is a remarkable case proving that chronic local intracranial pressure does not inevitably lead to neurologic symptoms or intellectual disabilities. ( info) |
117/469. Shunt dependency in shunted arachnoid cyst: a reason to avoid shunting. Cystoperitoneal (CP) shunting is minimally invasive and achieves a high rate of resolution on neuroimaging. However, in the absence of definite symptoms, shunting should be reconsidered, because some patients can experience shunt dependency after CP shunting. In this study, the risk of shunt dependency in patients with arachnoid cysts treated with CP shunting and the management of these patients are described. Eight patients (7 boys and 1 girl) were diagnosed as shunt dependent following CP shunting. At the time of the first operation (mean age at first shunting 6.1 years, range 1-11 years), a causal relationship between symptoms and the arachnoid cyst was evident in only 2 cases. Clinical manifestations, neuroimaging (computed tomography and/or magnetic resonance imaging) and intracranial pressure (ICP) data were reviewed retrospectively. The mean age of the patients at the time of shunt dependency was 9.8 years (range 6-13 years), and the mean time between the first shunt operation and shunt dependency was 41 months (range 17-80 months). Although neuroimaging demonstrated a collapsed cyst and small ventricles in most patients, ICP monitoring revealed significant intracranial hypertension. The release of shunt ligation, revision or additional shunting, such as ventriculoperitoneal shunting or lumboperitoneal shunting, resulted in the complete resolution of symptoms except in one patient who lost vision. This study shows that shunt dependency after CP shunting is a real problem and requires more attention. ICP monitoring can demonstrate the presence of intracranial hypertension when clinical and radiological analyses do not. ( info) |
118/469. A case study of hemispatial neglect using finite element analysis and positron emission tomography. BACKGROUND: The authors present a patient who developed transient hemispatial neglect following surgical drainage of a large right frontotemporal arachnoid cyst. As symptoms evolved in parallel with brain shift over the subsequent months, the authors hypothesized that the disorder was associated with the appearance of mechanical stresses in the cerebral mantle. methods: To map tissue stress at the various stages of deformation, a finite element computer simulation was conducted on the basis of computed tomography scans of the patient. RESULTS: The authors' results demonstrate substantial shear and compressive stress concentrations in the parietal lobe, a region commonly associated with neglect, and where positron emission tomography confirmed hypoperfusion in this patient. Treatment with combined ventricular-peritoneal and cystoperitoneal shunts was accompanied by clinical recovery and improvement of right parietal lobe cerebral blood flow. CONCLUSIONS: The authors conclude that brain deformation was a contributing factor in the reversible neglect syndrome by compromising the normal flow of blood and/or the deactivation of subcortical circuits of the parietal lobe. ( info) |
119/469. First-trimester diagnosis of fetal arachnoid cyst: prenatal implication. We report a case of the early diagnosis of an arachnoid cyst. Transvaginal ultrasound examination of the fetal brain at 13 weeks' gestation revealed the presence of an anechoic mass above the posterior fossa. After extensive counseling and because of the uncertain prognosis of a first-trimester diagnosis of an arachnoid cyst, the parents opted for termination of pregnancy. The diagnosis was confirmed by postmortem examination. ( info) |
120/469. Endoscopic fenestration of posterior fossa arachnoid cyst for the treatment of presyrinx myelopathy--case report. A 32-year-old man presented with an arachnoid cyst of the posterior fossa manifesting as cervical syringomyelic myelopathy. Magnetic resonance (MR) imaging demonstrated edematous enlargement and T2 prolongation of the cervical spinal cord, indicating a "presyrinx" state. MR imaging showed the inferior wall of the cyst, which disturbed cerebrospinal fluid (CSF) pulsatile movement between the intraspinal and intracranial subarachnoid spaces. The cyst wall was fenestrated with a neuroendoscope. The presyrinx state and the CSF movement improved. Posterior fossa arachnoid cyst, as well as Chiari malformation, can cause CSF flow disturbance at the craniocervical junction and syringomyelia. Endoscopic fenestration is less invasive than foramen magnum decompression and should be the procedure of choice. ( info) |