Dandy-Walker syndrome

1981 ◽  
Vol 55 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Raymond Sawaya ◽  
Robert L. McLaurin
Keyword(s):  
Corpus Callosum ◽  
Posterior Fossa ◽  
Intellectual Development ◽  
Psychometric Testing ◽  
Clinical Analysis ◽  
Mental Development ◽  
Associated Anomalies ◽  
Content Type ◽  
Walker Malformation ◽  
Fine Print

✓ A clinical analysis of 23 patients with Dandy-Walker malformation indicates that more than 85% of them were diagnosed at or before 1 year of age, and that the incidence of associated anomalies is approximately 50%, with a 17% incidence for agenesis of the corpus callosum. The significance of the presence of these anomalies is substantiated by the fact that of the seven deaths recorded, six were related to this disease and five were affected by associated anomalies. The high mortality rate (26%) is comparable to that of other series. The differential diagnosis with posterior fossa extra-axial cysts is discussed. Ten patients were primarily treated with excision of the cyst membrane; all of them required subsequent shunting to control the intracranial pressure, demonstrating the futility of this approach. None of the patients treated with lateral ventricle shunting suffered an upward herniation of the posterior fossa contents, suggesting that combined shunting of the lateral and fourth ventricles is rarely necessary. The technical advantages of posterior fossa shunting alone are outlined. Of the 16 survivors, 14 were assessed for their mental development by means of standard psychometric testing. The results of the intelligence quotient (IQ) scoring have indicated that 71% of the patients have subnormal mental development (IQ < 83). There was no significant relationship between retardation and associated anomalies, although agenesis of the corpus callosum was related to poor intellectual development in the two patients so affected (IQ's of 50 and 73).

Anterior communicating artery aneurysms with associated anomalies

1980 ◽  
Vol 52 (2) ◽  
pp. 162-164 ◽  
Author(s):  
Ryungchan Kwak ◽  
Hiroshi Niizuma ◽  
Mitsuaki Hatanaka ◽  
Jiro Suzuki
Keyword(s):  
Corpus Callosum ◽  
Cerebral Aneurysm ◽  
Occurrence Rate ◽  
Anterior Communicating Artery ◽  
Associated Anomalies ◽  
Content Type ◽  
Anterior Communicating Artery Aneurysms ◽  
Median Artery ◽  
Arterial Anomalies ◽  
Fine Print

✓ In 296 cases with a single aneurysm of the anterior communicating artery (ACoA), fenestration or the presence of more than two ACoA's was observed in 17 cases (5.7%), and abnormal vessels of ACoA origin, such as a median artery of the corpus callosum, were observed in 13 cases (4.4%). As more than one anomaly was found in some of these cases, anomalies of the ACoA were found in a total of 26 cases (8.8%). This occurrence rate was no higher than that observed in other cerebral aneurysm cases and in the control cases, which were reported previously. There was no significant increase of hypoplasia of the A1 portion if the ACoA aneurysm was complicated by other arterial anomalies.

The relationship of Arnold-Chiari and Dandy-Walker malformations

1972 ◽  
Vol 36 (4) ◽  
pp. 481-486 ◽  
Author(s):  
W. James Gardner ◽  
J. Lawton Smith ◽  
Dorcas H. Padget
Keyword(s):  
Posterior Fossa ◽  
Chiari Malformation ◽  
Content Type ◽  
Arnold Chiari Malformation ◽  
Dandy Walker Malformation ◽  
Walker Malformation ◽  
Relationship Of ◽  
The Relationship ◽  
Fine Print

✓ The posterior fossa is abnormally small in cases of Arnold-Chiari malformation because the tentorium is too low, whereas it is abnormally large in the Dandy-Walker malformation because the tentorium is too high.

Arteriovenous malformations in the posterior fossa

1977 ◽  
Vol 47 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Hiroshi Matsumura ◽  
Yasumasa Makita ◽  
Kuniyuki Someda ◽  
Akinori Kondo
Keyword(s):  
Arteriovenous Malformation ◽  
Brain Stem ◽  
Posterior Fossa ◽  
Arteriovenous Malformations ◽  
Cerebellopontine Angle ◽  
Anterior Part ◽  
Content Type ◽  
The Brain ◽  
Fine Print

✓ We have operated on 12 of 14 cases of arteriovenous malformation (AVM) in the posterior fossa since 1968, with one death. The lesions were in the cerebellum in 10 cases (three anteromedial, one central, three lateral, and three posteromedial), and in the cerebellopontine angle in two; in two cases the lesions were directly related to the brain stem. The AVM's in the anterior part of the cerebellum were operated on through a transtentorial occipital approach.

Bilateral trigeminal neuralgia: a 14-year experience with microvascular decompression

1988 ◽  
Vol 68 (4) ◽  
pp. 559-565 ◽  
Author(s):  
Ian F. Pollack ◽  
Peter J. Jannetta ◽  
David J. Bissonette
Keyword(s):  
Trigeminal Neuralgia ◽  
Posterior Fossa ◽  
Microvascular Decompression ◽  
Pain Control ◽  
Symptom Control ◽  
Sensory Loss ◽  
Content Type ◽  
Cranial Nerve Dysfunction ◽  
Ablative Procedures ◽  
Fine Print

✓ Thirty-five patients with trigeminal neuralgia (TN) bilaterally underwent posterior fossa microvascular decompression (MVD) between 1971 and 1984. They comprised 5.0% of a larger series of 699 patients with TN who underwent MVD during that interval. Compared to the subgroup of 664 patients with only unilateral symptoms, the population with bilateral TN included a greater percentage of females (74% vs. 58%, p < 0.1), a higher rate of “familial” TN (17% vs. 4.1%, p < 0.001), and an increased incidence of additional cranial nerve dysfunction (17% vs. 6.6%, p < 0.05) and hypertension (34% vs. 19%, p < 0.05). Of the 35 patients with bilateral TN, 10 underwent bilateral MVD (22 procedures) and 25 underwent unilateral MVD (30 procedures). In the latter patients, pain on the nonoperative side was well controlled with medication alone or had previously been treated by ablative procedures. Good or excellent pain control was achieved after one MVD was performed in 40 of the 45 sides treated (89%), and was maintained 1, 5, and 10 years after surgery in 82%, 66%, and 60%, respectively, based on life-table analysis. Six of 10 patients with recurrent symptoms underwent repeat unilateral MVD. Good or excellent long-term pain control was maintained in all six. With these repeat procedures included, symptom control at 1, 5, and 10 years after initial surgery was maintained in 87%, 78%, and 78% of the treated sides, respectively. Overall, 26 of 35 patients (74%) maintained good or excellent pain relief throughout the duration of the study (mean follow-up period 75 months) without resumption of regular medication usage. Although preoperative neurological deficits resulting from previous ablative procedures were seen in the majority of patients before MVD, no patient developed new major trigeminal sensory loss or masseter weakness after MVD. Operative mortality was zero. The results indicate that posterior fossa MVD is an effective and relatively safe treatment for the majority of patients with bilateral “idiopathic” TN, avoiding the risks of bilateral trigeminal nerve injury seen with other approaches.

Meningeal melanocytoma

1998 ◽  
Vol 88 (1) ◽  
pp. 116-121 ◽  
Author(s):  
David B. Clarke ◽  
Richard Leblanc ◽  
Gilles Bertrand ◽  
Gilbert R. C. Quartey ◽  
G. Jackson Snipes
Keyword(s):  
Histological Examination ◽  
Posterior Fossa ◽  
Clinical Presentation ◽  
Residual Tumor ◽  
Posterior Fossa Decompression ◽  
Content Type ◽  
Meningeal Melanocytoma ◽  
Radiological Appearance ◽  
Histological Features ◽  
Fine Print

✓ Meningeal melanocytomas are rare tumors of the central nervous system that are found almost exclusively in the posterior fossa and spinal cord and whose natural history is poorly defined. In this report, the authors review the clinical presentation, radiological appearance, operative findings, and histological features in two cases of meningeal melanocytoma: one cranial and one spinal. Two women, aged 21 and 30 years, were admitted to the hospital 60 years apart: the first because of progressive paraplegia and the second because of slowly progressive hearing loss. The first patient had an extradural tumor that was treated by laminectomy, subtotal resection, and postoperative radiotherapy in 1936. Her symptoms recurred 16 years later and she underwent reoperation of the residual tumor, which was found to have an intradural component. The authors' patient, who presented 60 years later, underwent plain and enhanced computerized tomography and magnetic resonance imaging that demonstrated a large posterior fossa lesion indicative of either an acoustic neuroma or a meningioma. She underwent posterior fossa decompression but only partial excision of the tumor could be accomplished because vigorous bleeding limited the extent of the resection. Surgery was followed by radiotherapy. The residual tumor enlarged despite these measures and required repeated resection 6 months later. At the second operation the tumor was much less vascular, perhaps reflecting the effects of radiotherapy, and was removed almost entirely. The patient died 6 months later from an anticoagulant-related cerebellar hemorrhage. In both cases the lesions were jet black, and histological examination revealed melanin-containing hypercellular tumors with rare mitotic figures. Meningeal melanocytomas are being diagnosed with increased frequency in parallel with improvements in neuroimaging and clarification of histological features. Clinical presentation of patients with these tumors typically occurs in their fifth decade and women are affected twice as often as men. The posterior fossa lesions can mimic acoustic neuromas and meningiomas in location and radiological appearance; however, the internal auditory canal is normal. In the spine, meningeal melanocytomas present with the clinical features of myeloradiculopathy. Diagnosis is made intraoperatively from the gross, jet-black appearance of the tumor and from histological examination. Vascularity, size, and location may render complete resection unfeasible. Because of the tumor's propensity to recur, radiotherapy has been recommended but its role remains to be elucidated.

Lead encephalopathy presenting as a posterior fossa mass

1986 ◽  
Vol 65 (5) ◽  
pp. 713-715 ◽  
Author(s):  
J. Frederick Harrington ◽  
Timothy B. Mapstone ◽  
Warren R. Selman ◽  
Pamela Galloway ◽  
Carl Bundschuh
Keyword(s):  
Computerized Tomography ◽  
Posterior Fossa ◽  
Content Type ◽  
Lead Encephalopathy ◽  
Fine Print

✓ A case of lead encephalopathy with clinical and computerized tomography evidence of a midline posterior fossa mass is presented. The pathophysiology and the predilection for posterior fossa involvement are discussed.

Diagnostic value of 201Tl—single-photon emission computerized tomography studies in cases of posterior fossa hemangioblastomas

2001 ◽  
Vol 95 (2) ◽  
pp. 292-297 ◽  
Author(s):  
Takeo Kondo ◽  
Toshihiro Kumabe ◽  
Shin Maruoka ◽  
Takashi Yoshimoto
Keyword(s):  
Computerized Tomography ◽  
Posterior Fossa ◽  
Single Photon ◽  
Photon Emission ◽  
Magnetic Resonance Images ◽  
Thallium 201 ◽  
Homologous Region ◽  
Single Photon Emission ◽  
Content Type ◽  
Fine Print

Object. The 201Tl uptake index was evaluated for its usefulness in formulating a diagnosis of hemangioblastoma. Thallium-201—single-photon emission computerized tomography (SPECT) studies were performed in nine patients harboring hemangioblastomas in the posterior fossa and in five patients (six lesions) with gliomas in the posterior fossa. Methods. The 201Tl uptake index was defined as the ratio of mean counts of isotope per pixel in the tumor to mean counts of isotope per pixel in the homologous region of the healthy brain. The 201Tl uptake indices of the early image (TlE) and that of the delayed image (TlD) were calculated. The isotope retention index (RI) was calculated as (TlE − TlD)/TlE. The TlE was 2.7 ± 0.7 in hemangioblastomas and 2.9 ± 1.7 in gliomas (mean ± standard deviation). The TlD was 1.5 ± 0.4 in hemangioblastomas and 2.4 ± 1.6 in gliomas. There were no significant differences between hemangioblastomas and gliomas when TlEs and TlDs were compared. The isotope RI was 0.43 ± 0.07 in hemangioblastomas and 0.15 ± 0.1 in gliomas, showing a significantly higher RI in hemangioblastomas compared with gliomas (p < 0.01). Conclusions. Thallium-201 washout is significantly faster in hemangioblastomas. Hemangioblastoma is biologically benign, but contains a rich capillary network that forms a hypervascular tumor bed. Variations in its appearance on magnetic resonance images may cause difficulties in the differential diagnosis of hemangioblastoma. Thallium-201 SPECT studies can be used to distinguish hemangioblastomas from gliomas in the posterior fossa.

Successful evacuation of a pontine hematoma secondary to rupture of a pathologically diagnosed “cryptic” vascular malformation

1973 ◽  
Vol 39 (1) ◽  
pp. 104-108 ◽  
Author(s):  
Ben B. Scott ◽  
Joachim F. Seeger ◽  
Richard C. Schneider
Keyword(s):  
Arteriovenous Malformation ◽  
Brain Stem ◽  
Posterior Fossa ◽  
Vascular Malformation ◽  
Nerve Palsy ◽  
Neurological Deficits ◽  
Content Type ◽  
Brain Stem Lesion ◽  
Seventh Nerve ◽  
Fine Print

✓ A posterior fossa exploration was performed on a child thought initially to have an inoperable brain stem lesion. A pontine hematoma was discovered and evacuated. The pathological specimen was designated as a “cryptic” arteriovenous malformation. All preoperative neurological deficits disappeared except for a minimal left seventh nerve palsy.

Interhemispheric approach for the surgical removal of thalamocaudate arteriovenous malformations

1987 ◽  
Vol 66 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Robert A. Solomon ◽  
Bennett M. Stein
Keyword(s):  
Corpus Callosum ◽  
Arteriovenous Malformations ◽  
Surgical Removal ◽  
Cerebral Arteriovenous Malformations ◽  
Total Removal ◽  
Recurrent Hemorrhage ◽  
Content Type ◽  
Interhemispheric Approach ◽  
Parinaud’S Syndrome ◽  
Fine Print

✓ A series of 250 surgically treated cerebral arteriovenous malformations (AVM's) is presented, in which 22 lesions were located primarily in the thalamus and caudate nucleus. A standardized interhemispheric approach through the posterior corpus callosum and into the atrium of the lateral ventricle was utilized for the surgical removal of these AVM's. Total removal was confirmed by angiography in 18 patients; removal was subtotal in four cases. There were no deaths in this group of patients. Disturbances of recent memory pre- and postoperatively were seen in half of the patients, but most of these deficits were temporary. Other complications included: postoperative homonymous hemianopsia (six cases), transient hemiparesis (three cases), hemisensory loss (two cases), Parinaud's syndrome (one case), and recurrent hemorrhage 2 years after surgery (one case). All 22 patients returned to their previous occupations and are leading independent lives. The results of this experience indicate that thalamocaudate AVM's can be effectively treated by resection.

Use of ligamentum nuchae graft for dural closure in posterior fossa surgery

1998 ◽  
Vol 89 (1) ◽  
pp. 155-156 ◽  
Author(s):  
Edward J. Kosnik
Keyword(s):  
Cerebrospinal Fluid ◽  
Posterior Fossa ◽  
Cerebrospinal Fluid Leakage ◽  
Posterior Fossa Surgery ◽  
Content Type ◽  
Fluid Leakage ◽  
Dural Closure ◽  
Fine Print

✓ The technique of harvesting the ligamentum nuchae and its use in posterior fossa surgery are discussed. By using this technique the author has avoided postoperative cerebrospinal fluid leakage in more than 200 procedures.

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