Posterior fossa arachnoid cysts.

Arachnoid cysts of the posterior fossa are rare lesions that are considered to be mostly congenital in origin. In this article, we retrospectively review 12 patients who underwent surgical treatment for their symptomatic posterior fossa arachnoid cysts. The most common presenting symptoms were gait disturbances and headache. The diagnosis was established on computed tomography or magnetic resonance imaging. Surgery consisted of cyst wall excision with fenestration in nine cases and shunting procedures in three cases. In all cases except one who-died, the postsurgical follow-up neuroradiological investigations showed that the cysts had decreased in size, the cerebellum had re-expanded, and if there was preoperative hydrocephalus, the ventricular size was decreased. The follow-up period ranged from 1 to 11 years. All surviving cases are free of symptoms and no arachnoid cysts recurred. The classification, pathophysiology, differential diagnosis and surgical treatment of infratentorial arachnoid cysts are discussed and the relevant literature is reviewed.     

Posterior fossa arachnoid cyst presenting with unilateral tremor

A rare case of unilateral benign essential tremor is presented that responded to surgical excision of a posterior fossa arachnoid cyst.     

Posterior fossa hemorrhage caused by dural arteriovenous fistula: case reports

BACKGROUND: Relatively few reports are available on dural arteriovenous fistulas (AVFs) accompanied by posterior fossa hemorrhage. We now report upon two such cases and discuss the differential diagnosis and imaging findings. CASE DESCRIPTION: A 36-year-old man was admitted after experiencing sudden headache. Computerized tomography (CT) showed vermian and fourth ventricular hematoma, and magnetic resonance imaging (MRI) revealed an abnormal signal void. Angiography demonstrated a dural AVF in the region of foramen magnum. The second case, a 57-year-old man, was also admitted for the evaluation of headache. CT scan revealed tentorial subdural, subarachnoid and vermian hemorrhage. MRI showed vermian hematoma and an abnormal signal void below the tentorium. Angiography demonstrated a dural AVF in the tentorium.The first case underwent transarterial embolization, after which the dural AVF disappeared completely. The second case underwent craniotomy immediately after failure of endovascular therapy. Postoperative angiography demonstrated no remaining dural AVF. CONCLUSIONS: Dural AVF should be considered as a causative lesion in cases with posterior fossa hemorrhage with no other definitive cause.     

Dermoid & epidermoid cysts of the posterior cranial fossa with complete dermal sinus

Riassunto Gli. Aa. discutono i problemi clinici della cisti dermoidi ed epidermoidi della fossa cranica posteriore con seno dermico occipitale, ne espongono i dati morfogenetici e i rilievi anatomici, e passano in rassegna le caratteristiche dei pochi casi finora pubblicati.Espongono una loro osservazione del genere facendone risaltare il decorso clinico, costellato di episodi meningitici acuti subentranti, e le difficoltà dell'estirpazione operatoria.

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Summary The Aa. discuss the clinical problems connected with the development of epidermoids and dermoids of the posterior fossa. Morphogenetical and anatomical features are mentioned, while the cases, which have been published are enumerated and commented upon.A case is described of a child with a dermoid of the posterior fossa (with complete dermal sinus), complicated by repeated bouts of meninigitis, which rendered more difficult operative procedures.

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Zusammenfassung Die Autoren diskutieren die klinischen Probleme derjenigen Dermoide und Epidermoide der hinteren Schädelgrube, die mit einem Zapfen, d. h. mit einer Art Fistelgang mit der Haut in Verbindung stehen. Morphologische und anatomische Daten werden zusammen mit den wenigen bisher im Schrifttum veröffentlichten derartigen Fällen besprochen. Beschreibung eines eigenen Falles, bei dem mehrere meningitische Schübe Schwierigkeiten des Verlaufes und der Exstirpation des Tumors bedingten.

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Resumen Los autores discuten los problemas elínicos relacionados con el desarrollo de los quistes dermoides y epidermoides de la fosa craneal posterior. Se mencionan especialmente los rasgos morfológicos y anatómicos de éstos procesos, efectuandose también una revisión y comentario de los casos publicados en la literatura.Se describe un caso de un niño con un dermoide de la fosa posterior (con un seno dérmico completo) que estuvo complicado por episodios repetidos de meningitis que dificultaron las maniobras operatorias.

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Résumé Les Aa. discutent la Symptomatologie des kystes épidermoïdes et dermoïdes de la fosse postérieure avec ou sans sinus dermique, et décrivent les donnés pathogéniques et anatomiques, tenant compte des cas publiés.Ils exposent un cas personnel de kyste dermoide de la fosse postérieure avec synus occipital complet, qui fut compliqué par des accidents méningés répétés, ce qui engendra des difficultés dans l'extirpation du kyste.

     

Dermoid and epidermoid cysts of the midline in the posterior cranial fossa

Clinical features and surgical outcome of 16 patients with dermoid or epidermoid cysts on the midline of the posterior cranial fossa are compared. Salient points in the comparison are the younger age, presence of associated malformations and better prognosis of dermoid cyst.     

An unusual middle fossa interdural epidermoid tumor. Case report.

The authors report an unusual case of an intracranial, interdural epidermoid tumor and cyst in a 72-year-old woman who presented with longstanding, mild numbness over her right cheek. She was initially treated conservatively, but on follow-up review the mass was found to have grown and evidence of hemorrhage was present, and therefore a subtotal resection was performed. This case should probably be classified as a paratrigeminal, interdural epidermoid cyst; this is the first known report in which magnetic resonance and computerized tomography images of such an entity are presented and discussed.     

Paramedian hourglass epidermoid cysts extending in the middle and posterior cranial fossa

Four cases of large paramedian hourglass epidermoid tumors extending both in the middle and posterior cranial fossa are reported and other 16 cases from the literature are reviewed. The length of the clinical history and the triviality of neurological symptoms in spite of the size of the tumor are emphasized. CT scanning well documents the extension of these epidermoids and usually consents to differentiate them from the arachnoid cysts. The subtemporal transtentorial approach is more advisable, although a two-stage operation by subtemporal and suboccipital route can be necessary in some cases. Nevertheless the difficulties and the risk of the surgical treatment make very hard the complete removal of the tumor in most cases.     

Posterior fossa arachnoid cyst presenting as high cervical cord compression

We report a 16-year-old boy who presented with high cervical cord compression caused by a midline posterior fossa arachnoid cyst lying below the vermis. Cystoperitoneal shunting resulted in a dramatic improvement of neurological signs.     

Posterior fossa arachnoid cysts and cerebellar tonsillar descent: short review

The objective of this study was to analyze the association of cerebellar tonsillar descent and syringomyelia in patients with posterior fossa arachnoid cysts. We reviewed the medical records of ten patients (mean, age 33; range, 24–49 years) diagnosed with posterior fossa arachnoid cyst and tonsillar descent. Symptoms evolved over a mean of 12 months (range, 6 months to 3 years). Syringomyelia was present in six cases. Six patients underwent a suboccipital craniectomy, three cases underwent an additional C1 laminectomy, and a further case had a limited craniectomy and tonsillar reduction. Three patients were also treated for hydrocephalus: one with a ventriculoperitoneal shunt and two with endoscopic third ventriculostomy. Two patients had conservative treatment. The posterior fossa arachnoid cysts were located at the vermis-cisterna magna (n = 4), the cerebellar hemispheres (n = 2), the cerebellopontine angle (n = 3), and the quadrigeminal cistern (n = 1). A patient with achondroplasia showed features of platybasia. Associated malformations included craniofacial dysmorphism in a patient diagnosed of trichorhinophalangeal syndrome and a case with a primary temporal arachnoid cyst. After a mean follow-up of 2 years (range, 3 months to 5 years), four patients showed resolution of their neurological symptoms, and two exhibited persisting ocular findings. Headaches and nuchalgia improved in four cases and persisted in four. Syringomyelia was resolved in four patients and improved in two. Patients harboring a posterior fossa arachnoid cyst may evolve with acquired Chiari malformation and syringomyelia. Initial management should be directed to decompressing the foramen magnum and should include the resection of the arachnoid cyst’s walls. A wait-and-see attitude can be implemented in selected cases. In our experience, hydrocephalus should be properly addressed before treating the arachnoid cyst.     

A case presenting with hydrocephalus and posterior fossa subdural effusion

We report a case of hydrocephalus due to posterior cranial fossa subdural effusion. The patient was a 4-year-old boy, presenting headache and nausea, with a medical history of viral meningitis 2 months before. Cerebrospinal fluid provided no evidence of infection, and symptoms caused by increased intracranial pressure gradually deteriorated, although glycerol infusion was effective temporarily. Computed tomography revealed marked ventriculomegaly with subdural effusion in the right posterior cranial fossa. The subarachnoid space in the posterior fossa was very tight, and the cerebellum and brain stem were compressed anteriorly. Magnetic resonance imaging demonstrated stenosis of the aqueduct and foramens of Luschka and Magendie. The cerebeller tonsil was dislocated inferiorly, indicating impending herniation, so an emergency operation was performed. Ventriculoperitoneal shunt was undertaken after implantation of an Ommaya reservoir for the posterior fossa subdural effusion. The patient's postoperative course was uneventful, and the symptoms were improved. Although hydrocephalus and subdural effusion following viral meningitis is rare, neuroimaging studies such as CT and MRI should be examined when a young child suffers from symptoms of increased intracranial pressure.     

Young women presenting with chronic mesenteric ischemia--two case reports

Chronic mesenteric ischemia is primarily a disease of the elderly, who have widespread atherosclerosis of the celiac, superior mesenteric, and inferior mesenteric arteries. Risk factors include smoking, vasculitis, fibromuscular dysplasia, and arterial dissection. Presented here are 2 cases of women under age 50 years burdened with this condition, owing primarily to advanced arteriosclerosis. These cases illustrate a need for increased awareness of mesenteric ischemia as a cause for postprandial abdominal pain in young patients with other stigmata of advanced arterial occlusive disease.     

Arachnoid cysts of the middle fossa and associated subdural hematoma. Three case reports and review of the literature

BACKGROUND AND PURPOSE: We report 3 cases of subdural hematoma associated with arachnoid cyst of the middle fossa, and discuss the treatment. METHODS: Three males aged 33, 63 and 68 were treated in our institution. Before this event the cyst was asymptomatic and unknown. Magnetic resonance imaging was the most contributive radiologic exam. Surgical procedure was limited to subdural hematoma evacuation. The internal wall of subdural hematoma was opened in all cases. RESULTS: The clinical outcome was good for all patients. The CT or MRI scan follow-up 3 months later revealed nearly total disappearance of subdural hematoma for 2 out of 3 cases. For one patient the volume of arachnoid cyst decreased. CONCLUSIONS: We propose subdural hematoma drainage without any specific treatment (shunt or fenestration) of the arachnoid cyst, for this category of patient.     

Posterior radiocarpal fracture-dislocation (eight case reports)

The Authors report a retrospective series of eight cases of posterior radiocarpal fracture-dislocation. Average age of patients was 32 years (23/54), with a male predominance (7 men and a woman). Injury was often due to a fall on the hand in extension from an elevated place (5/8). The wrist in back of fork is the characteristic deformity. Diagnosis was confirmed by AP and lateral views of the wrist. Radial stylo?d fracture, posterior dislocation of the carpus and posterior rim avulsion were constant. Ulnar stylo?d fracture was present in half of the cases and distal radio-ulnar dislocation in two cases. Four patients were treated conservatively and four surgically. Whatever the treatment choice, results are satisfactory at a short follow-up. The two patients presenting a distal radio-ulnar dislocation resulted in a bad result.