bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcranial Magnetic Stimulation of the Facial Nerve: Recording Technique and Estimation of the Stimulated Site
Authors: Seki Yojiro , Krain Larry , Yamada Thoru , Kimura Jun
Published: April 2011

We compared transcranial magnetic and conventional electrical stimulation in 20 facial nerves of 10 normal subjects. A magnetic coil was placed tangentially over T5 or T6 (10-20 electroencephalogram electrode placement system) and electrical stimulation was applied 1 cm below the anterior tragus. Compound muscle action potentials recorded from the ipsilateral nasalis muscle showed onset latencies (mean ± SD) of 4.48 ± 0.50 ms with magnetic stimulation and 3.15 ± 0.40 ms with electrical stimulation, a mean difference of 1.33 ± 0.14 ms. Stimulation of the extracranial facial nerve at two sites yielded a conduction velocity of 59.6 ± 4.5 m/s. Based on these findings, the magnetically stimulated site was estimated to fall 79.0 ± 8.6 mm proximal to the point of electrical stimulation. Taking the average length of the nerve trunk and histological specificity of the root exit zone into consideration, evidence indicates that the root exit zone of the facial nerve is the most likely initiating site of excitation with magnetic stimulation.
Multilevel Lumbar Laminotomies: An Alternative to Laminectomy in the Treatment of Lumbar Stenosis
Authors: Aryanpur John , Ducker Thomas
Published: April 2011

The traditional treatment for lumbar stenosis is a wide laminectomy. This procedure has a high success rate and a low, but not insignificant, incidence of complications. Recently, however, a better understanding of the pathophysiology of spondylotic lumbar stenosis has led several authors to propose a more limited decompression directed specifically toward the offending area of compression. Over the past 5 years, we have treated 32 patients with lumbar stenosis using decompressive laminotomies. Our patients all had focal lateral recess stenosis that was diagnosed by computed tomography or magnetic resonance imaging. We performed decompressive laminotomies and foraminotomies at appropriate levels. This procedure is less disruptive than a full laminectomy and. in experienced hands. requires less operating time. At last follow-up. 90% of the patients so treated reported an excellent outcome-namelv. total relief of symptoms and/or return to normal daily activities. There was no significant postoperative morbidity or mortality. We conclude that in a selected subgroup of patients with lumbar stenosis, multilevel laminotomies may be an acceptable alternative to laminectomy.
Delayed and Progressive Multiple Suture Craniosynostosis
Authors: Reddy Kesava , Hoffman Harold , Armstrong Derek
Published: April 2011

A considerable amount of information is available on various types of craniosynostoses. The patient exhibiting single suture synostosis that progresses to involve multiple sutures is distinctly uncommon, as is the patient exhibiting delayed synostosis involving all of the calvarial sutures. We report a group of 11 such patients with progressive and delayed holocalvarial synostosis. Most patients exhibited features of raised intracranial pressure or developmental delay, and in all patients symptoms were relieved after surgery. The diagnostic and therapeutic implications of this type of presentation in craniosynostosis are discussed.
Surgical Removal of Pontomesencephalic Cavernous Hemangiomas
Authors: Fahlbusch R. , Strauss C. , Huk W. , Röckelein G. , Kömpf D. , Ruprecht K. W.
Published: April 2011

Cavernous hemangiomas of the brain stem are usually discovered accidentally during evacuation of a hematoma, and successful surgical treatment of these lesions is seldom achieved. With the increasing use of magnetic resonance imaging, the presence of a cavernous hemangioma can be detected before surgery, allowing an elective surgical approach. We successfully removed pontomesencephalic cavernous hemangiomas from 2 patients and pontomedullary hemangiomas from 2 others. Elective surgery was performed with perioperative bimodal monitoring of somatosensory and auditory evoked potentials. Performing surgery soon after the hemorrhage minimizes the risk of additional postoperative neurological deficit, since surgical excision is facilitated when the hematoma is not completely organized. Pontine hemangiomas are approached via the 4th ventricle. Mesencephalic hemangiomas are removed by a midline supracerebellar approach when they are lateralized by using a subtemporal approach. The lesion can be removed through a small incision in the brain stem at the site of the lesion. The favorable results, which include marked improvement of preoperative neurological deficits and documentation of complete removal of the lesion by magnetic resonance imaging, support a more aggressive approach to the treatment of symptomatic cavernous hemangiomas of the brain stem. Further investigation of the natural history of these lesions is mandatory.
Intracranial Vertebral Endarterectomy
Authors: Ausman James I. , Diaz Fernando G. , Sadasivan Balaji , Dujovny Manuel
Published: April 2011

Intracranial vertebral endarterectomy was performed on six patients with vertebrobasilar insufficiency in whom medical therapy failed. The patients underwent operations for stenotic plaque in the intracranial vertebral artery with the opposite vertebral artery being occluded, hypoplastic, or severely stenosed. In four of the patients, the stenosis was mainly proximal to the posterior inferior cerebellar artery (PICA). In this group, after endarterectomy, the vertebral artery was patent in two patients, and their symptoms resolved: in one patient the endarterectomy occluded, but the patient's symptoms improved; and in one patient the endarterectomy was unsuccessful, and he continued to have symptoms. In one patient, the plaque was at the origin of the PICA. The operation appeared technically to be successful, but the patient developed a cerebellar infarction and died. In one patient the stenosis was distal to the PICA. During endarterectomy, the plaque was found to invade the posterior wall of the vertebral artery. The vertebral artery was ligated, and the patient developed a Wallenburg syndrome. The results of superficial temporal artery to superior cerebellar artery anastomosis are better than those for intracranial vertebral endarterectomy for patients with symptomatic intracranial vertebral artery stenosis. The use of intracranial vertebral endarterectomy should be limited to patients who have disabling symptoms despite medical therapy, a focal lesion proximal to the PICA, and a patent posterior circulation collateral or bypass.
Subarachnoid-Pleural and Subarachnoid-Mediastinal Fistulae
Authors: Pollack Ian I. F. , Pang Dachling , Hall Walter A.
Published: April 2011

Subarachnoid-pleural fistula and subarachnoid-mediastinal fistula are rare complications of chest trauma. One case each of subarachnoid-mediastinal fistula and subarachnoid-pleural fistula is described. Both patients were young children who suffered severe longitudinal distraction injuries to their thoracic spine and exhibited complete cord transection without radiographic evidence of vertebral column injury. Progressive mediastinal widening and enlarging pleural effusion in the absence of angiographic evidence of aortic injury suggested the diagnosis of an intrathoracic cerebrospinal fluid fistula. Myelograms identified the site of spinal cord rupture and cerebrospinal fluid leakage. The diagnosis. management, and outcome of these rare fistulae are discussed.
Direct Repair of an Extracranial Vertebral Artery Pseudoaneurysm: Case Report and Review of the Literature
Authors: de los Reyes R. A. , Moser Franklin G. , Sachs David P. , Boehm Harrison F.
Published: April 2011

A case of a 47-year-old man with weakness secondary to ossification of the posterior longitudinal ligament is presented. During removal of the ossified ligament, the patient's dominant right vertebral artery was injured. Although the bleeding from this artery was controlled intraoperatively, the patient developed an expanding cervical hematoma on the 3rd postoperative day. An angiogram demonstrated a large pseudoaneurysm of the right vertebral artery. The patient was taken back to the operating room where the cervical hematoma was removed, and direct repair of the pseudoaneurysm of the vertebral artery was performed. The previously reported cases of pseudoaneurysms of the extracranial vertebral artery are reviewed. We advocate the use of direct vascular repair as the treatment of choice in these lesions.
Surgical Excision of Cerebral Arteriovenous Malformations: Late Results
Authors: Heros Roberto C. , Korosue Kazuyoshi , Diebold Paula M.
Published: April 2011

A follow-up study of 153 consecutive patients who underwent complete excision of an angiographically visualized intracerebral arteriovenous malformation was conducted. The follow-up period ranged from 0.5 to 10.6 years, with a mean of 3.8 years. The presenting clinical event was hemorrhage in about one-half of the patients and seizure in about one-third. There was a marked tendency for postoperative neurological deficits to improve with time, so that whereas the immediate postoperative rate of serious morbidity was 24.2%, only 7.8% of the patients were found to have serious morbidity at follow-up. An additional 3 patients had died. one of an unrelated carcinoma, making the mortality related to arteriovenous malformation 1.3%. The classification of Spetzler and Martin (43) was used retrospectively; the percentages of Grade I (easiest) through Grade V (most difficult) lesions were 7.8%, 22.9%, 28.8%, 26.8%, and 13.8%, respectively. The early result was well correlated to grade, with good or excellent results in 100%, 94.3%, 88.6%, 61%, and 28.6% of the patients in Grades I through V, respectively. At follow-up, 98.7% of the patients with arteriovenous malformations of Grades I, II, and III were in good or excellent condition. The late morbidity and mortality rates for the patients in Grades IV and V were 12.2% and 38.4%, respectively. Of the patients who did not have seizures before surgery, 8.2% had only one or two seizures during the immediate postoperative period, and 7.1% had late seizures that were well controlled with medication in all. Of the patients who had seizures before surgery, over half were either cured or greatly improved with respect to the seizures. In 32.7% there was no change in the frequency of the seizures, and in 12.7% the seizures were more frequent after surgery. There was no history of either proven or suspected intracranial hemorrhage in any of the patients during the entire follow-up period, which in the aggregate totalled 556.3 years.
Unilateral Hydrocephalus Caused by an Intraventricular Venous Malformation Obstructing the Foramen of Monro
Authors: Tien Robert , Harsh Griffith R. , Dillon William P. , Wilson Charles B.
Published: April 2011

Unilateral hydrocephalus in an adult was caused by obstruction of the left foramen of Monro by an intraventricular venous malformation. Magnetic resonance imaging of the region of the foramen of Monro demonstrated the lesion, which subsequently was confirmed to be a venous malformation by angiography and surgery.
Posttraumatic Ligamentous Disruption of the Cervical Spine, an Easily Overlooked Diagnosis: Presentation of Three Cases
Authors: Fazl M. , LaFebvre J. , Willinsky R. A. , Gertzbein S.
Published: April 2011

Three patients with hyperflexion sprain of the cervical spine secondary to motor vehicle accidents are discussed. One patient exhibited tetraplegia and the other two only had paresthesia of the upper and/or lower extremities at the scene of the accident. All patients were young with no evidence of degenerative disc disease or osteoarthritis. Diagnosis of hyperflexion sprain is suggested by transient or persistent neurological deficits, local tenderness, or plain film findings, which include interspinous fanning, localized kyphotic angulation, subluxation, or disc space narrowing. Review of our patients' records revealed that some of these findings were evident at their initial presentation. In patients who have no neurological deficits, controlled flexion and extension views after routine plain films may be diagnostic of an unstable cervical spine. If there is a persistent neurological deficit, a magnetic resonance imaging scan is the examination of choice. If there is no compression of the thecal sac or spinal cord, supervised flexion and extension views of cervical spine should be done. Definitive management of the unstable spine is operative fixation.
Suprasellar Ectopic Pituitary Adenoma: Case Report and Review of the Literature
Authors: Matsumura Akira , Meguro Kotoo , Doi Mikio , Tsurushima Hideo , Tomono Yuji
Published: April 2011

The occurrence of a totally suprasellar ectopic pituitary adenoma in a 71-year-old man is described. The tumor was attached to the pituitary stalk, extending upward toward the third ventricle. No intrasellar lesion was observed. Histological examination revealed a pituitary adenoma with large numbers of eosinophilic cells with moderate nuclear polymorphism and rare mitosis. Immunohistochemical staining revealed that the tumor cells were strongly positive for anti-adrenocorticotropic hormone antibody. A review of five previously reported intracranial ectopic pituitary adenomas revealed that two were silent corticotropic tumors and two occurred with Cushing's syndrome.
Testicular Germ Cell Tumor with Pineal Metastases
Authors: Delahunt Brett , Teoh Heng H. , Balakrishnan V. , Nacey John N. , Clark Simon P.
Published: April 2011

A patient with a mixed testicular germ cell tumor (choriocarcinoma, teratocarcinoma and embryonal carcinoma) that had metastasized to the lungs, cerebrum, and pineal gland is presented. The metastases had resulted in localized neurological signs and initially, on clinical grounds, a primary intracranial lesion could not be excluded. The occurrence of tumor metastases to the pineal gland is discussed and the literature is reviewed.
Radiosurgery for Acoustic Neurinomas: Early Experience
Authors: Linskey Mark E. , Lunsford Dade L. , Flickinger John C.
Published: April 2011

We reviewed our early experience with the first 26 patients with acoustic neurinomas (21 unilateral, 5 bilateral) treated by stereotactic radiosurgery using the first North American 201-source cobalt-60 gamma knife. Follow-up ranged from 6 to 19 months (median, 13 months). Serial postoperative imaging showed either a decrease in tumor size (11 patients) or growth arrest (15 patients). Loss of central contrast enhancement was a characteristic change (18 patients). Seven patients had good or serviceable hearing preoperatively. In all 7 the preoperative hearing status was retained immediately after radiosurgery. At follow-up, 3 had preserved hearing, I had reduced hearing, and 3 had lost all hearing in the treated ear. Hearing in 1 patient that was nonserviceable preoperatively later improved to a serviceable hearing level. Delayed facial paresis developed in 6 patients, and delayed trigeminal sensory loss developed in 7 patients, none of whom had significant deficits before radiosurgery. Both facial and trigeminal deficits tended to improve within 3 to 6 months of onset with excellent recovery anticipated. Lower cranial nerve dysfunction was not observed. All 26 patients remain at their preoperative employment or functional status. At present, stereotactic radiosurgery is an alternative treatment for acoustic neurinomas in patients who are elderly, have significant concomitant medical problems, have a tumor in their only hearing ear, have bilateral acoustic neurinomas, refuse microsurgical excision, or have recurrent tumor despite surgical resection. Although longer and more extensive follow-up is required, the control of tumor growth and the acceptable rate of complications in this early experience testifies to the future expanding role of this technique in the management of selected acoustic neurinomas.
Efficacy of Closed-System Drainage in Treating Chronic Subdural Hematoma: A Prospective Comparative Study
Authors: Wakai Susumu , Hashimoto Kazuyoshi , Watanabe Naofumi , Inoh Satoshi , Ochiai Chikayuki , Nagai Masakatsu
Published: April 2011

The authors conducted a prospective comparative study on the recurrence rate of chronic subdural hematoma after the use of two different treatment modalities: burr-hole irrigation of the hematoma cavity with (Group A) and without closed-system drainage (Group B). Thirty-eight patients were studied. Patients were assigned to groups sequentially upon admission. There were no significant differences between the two groups for age, sex, preoperative hematoma volume, and density on computed tomographic scan. One patient in Group A (5%) suffered a recurrence as opposed to 6 in Group B (33%). The difference in recurrence rate between the two groups was statistically significant (p < 0.05). The authors conclude that closed-system drainage after burr-hole irrigation reduces the recurrence rate of chronic subdural hematoma.
Long-Term Results of Percutaneous Retrogasserian Thermorhizotomy for “Essential” Trigeminal Neuralgia: Considerations in 1000 Consecutive Patients
Authors: Broggi Giovanni , Franzini Angelo , Lasio Giovanni , Giorgi Cesare , Servello Domenico
Published: April 2011

Long-term results (average follow-up, 9.3 years) obtained in 1000 consecutive patients suffering from cryptogenetic (“essential”) trigeminal neuralgia treated with percutaneous thermorhizotomy are analyzed. Pain relief was obtained in 95% of the treated patients. Permanent morbidity was as follows: masseter weakness in 105 patients; oculomotor palsies in 5 patients; weakening of the corneal reflex in 197 patients, 6 of whom requested an ocular operation for keratitis; and painful dysesthesia in 52 patients, 15 of whom developed a painful anesthesia syndrome. There was a recurrence rate of 18.1%, and a correlation between postoperative sensory deficit and the cure rate was found. These results are discussed and compared to the results obtained with different techniques.
Is Magnetic Resonance Imaging Useful in Guiding the Operative Approach to Large Pituitary Tumors?
Authors: Snow Robert B. , Johnson Carl E. , Morgello Susan , Lavyne Michael H. , Patterson Russel H.
Published: April 2011

Forty-two patients with large pitutary tumors were studied with magnetic resonance imaging scans. Based on the operative findings, the tumors were divided into two groups, Tumors in Group 1 (n = 35) were soft or partially necrotic and were easily removed by suction and curettage, Tumors in Group 2 (n = 7) were firm and required sharp dissection or use of the laser for removal. Tumors were divided into two groups based on the long TR signal: a) isointense in comparison with white matter, or b) hyperintense in comparison with white matter. All 7 firm tumors (Group 2) had an isointense signal on long TR sequences. Thirty-two of 35 soft tumors showed a hyperintense signal on long TR sequences, and 3 an isointense signal. Based on these results, we recommend a transsphenoidal approach for the initial operation in patients with large pituitary tumors. If the tumor is largely isointense on the magnetic resonance imaging scan, we discuss with the patient preoperatively the possibility (70% in this series) that the tumor may be too firm to remove in a single transsphenoidal procedure. In these circumstances, a second, transcranial, procedure may be required to decompress the suprasellar structures adequately.
Dural Arteriovenous Fistulas Supplied by Ethmoidal Arteries
Authors: Halbach Van V. , Higashida Randall T. , Hieshima Grant B. , Wilson Charles B. , Barnwell Stanley L. , Dowd Christopher F.
Published: April 2011

Eight patients with dural arteriovenous fistulas (DAVFs) located on the floor of the anterior cranial fossa and supplied by enlarged ethmoidal branches of the ophthalmic artery are described. Five patients showed the classical symptom of intracerebral hemorrhage (all five had ipsilateral frontal lobe hematomas and one also had an associated a subdural hematoma). Two patients exhibited atypical symptoms of proptosis, chemosis, elevated intraocular pressure, and loss of vision secondary to an ethmoidal DAVF, which drained posteriorly to the cavernous sinus. The eighth patient exhibited proptosis and chemosis secondary to a cavernous sinus DAVF and was incidentally found to have an asymptomatic ethmoidal DAVF. One additional patient had two separate dural fistulas: one located on the cribriform plate and the second located in the posterior fossa. Seven of the eight patients were cured by surgical excision of the fistula site; in the remaining patient spontaneous obliteration followed a surgical procedure for a cavernous DAVF. DAVFs involving the floor of the anterior cranial fossa usually present with hemorrhage, but can present with ocular symptoms or be entirely asymptomatic and are effectively treated by surgical excision of the fistula site.
Microsurgical Anatomy of the Cisternal Course of the Perforating Branches of the Posterior Communicating Artery
Authors: Vincentelli F. , Caruso G. , Grisoli F. , Rabehanta P. , Andriamamonjy C. , Gouaze A.
Published: April 2011

Both the perforating branches-especially the extracerebral segments-and the arachnoidal anatomy at the level of the posterior communicating artery were studied in 60 human brains previously fixed in formalin. The close relationships between this artery and the oculomotor nerve are described, and it is noted that each of them is enclosed in its own arachnoidal compartment, which in the case of the posterior communicating artery is to be distinguished from the interpeduncular cistern. The latter cistern was found to contain only the terminal segments of the posterior communicating artery. The hypothalamic branches were within the inner wall of the arachnoidal cistern surrounding the posterior communicating artery. The variations in diameter of this artery are explained by its embryological development and are not related to the number and the diameter of the perforators. The posterior communicating artery was absent at times. The surgical implications of such a variable anatomical arrangement are discussed in the light of the literature.
Postoperative Arteriovenous Fistula between the Middle Meningeal Artery and the Sphenoparietal Sinus
Authors: Tsutsumi Kazuo , Shiokawa Yoshiaki , Kubota Masaru , Aoki Nobuhiko , Mizutani Hiroshi
Published: April 2011

The authors report a case of postoperative middle meningeal arteriovenous fistula found after craniotomy for aneurysmal surgery using the pterional approach. It was no longer demonstrable at the follow-up examination 3 months later.
Persistent Hypoglossal Artery in Combination with Multifocal Arteriovenous Malformations of the Brain: Case Report
Authors: Garza-Mercado Romaá , Cavazos Elisamaria , Urrutia Gabriel
Published: April 2011

The persistence of embryonic cerebral vessels in the adult is not a frequent occurrence, neither is the presence of multifocal arteriovenous malformations (AVMs) of the brain. The most commonly reported type of persistent carotid-basilar anastomosis is the primitive trigeminal artery, followed by the primitive hypoglossal artery (PHA). In this report. a 30-year-old, right-handed woman hospitalized because of subarachnoid hemorrhage and harboring an intracerebral-intraventricular hematoma resulting from the rupture of one of two independent AVMs of the left cerebral hemisphere, was found also to have a right persistent PHA. One AVM was intraventricular and had ruptured: the other was subcortical, intact in the parietal lobe. The PHA originated as a large anomalous branch of the right internal carotid artery in the neck and joined the basilar artery after entering the posterior fossa through the ipsilateral anterior condyloid foramen, which was enlarged. At craniotomy, the two AVMs were successfully excised with the aid of microsurgical technique. These two independently rare conditions, namely, multifocal cerebral AVMs and persistent PHA, warrant our desire to report this case.
Aneurysms of the Intracavernous Carotid Artery: Natural History and Indications for Treatment
Authors: Linskey Mark E. , Sekhar Laligam N. , Hirsch William L. , Yonas Howard , Horton Joseph A.
Published: April 2011

Of 37 patients with 44 intracavernous carotid artery aneurysms (ICCAAns) diagnosed between 1976 and 1988. patients with 20 aneurysms were followed without treatment for 5 months to 13 years (median, 2.4 years). Ten of the 20 ICCAAns were asymptomatic at diagnosis, and 10 were symptomatic. Three of the asymptomatic ICCAAns were symptomatic at follow-up. One of these required clipping because of a progressing cavernous sinus syndrome; the other 2 were minimally symptomatic and have not required treatment. Of the 10 initially symptomatic ICCAAns, 2 had not changed, 4 became more symptomatic, and 4 had symptomatically improved by follow-up. One patient with an ICCAAn that had not changed clinically was lost to follow-up 6 months after diagnosis. Of the 4 ICCAAns that became more symptomatic, 2 continue to be monitored, and 2 required intervention; one with detachable balloon occlusion of the aneurysm with preservation of the internal carotid artery lumen, and the other with gradual cervical internal carotid artery occlusion. The clinical course of this selected group of patients with ICCAAns suggests that the natural history of ICCAAns can be quite variable. Although clinical progression does occur, symptomatic ICCAAns also can improve spontaneously. Therapeutic intervention for asymptomatic ICCAAns should be reserved for patients with aneurysms arising at the anterior genu of the carotid siphon and/or extending into the subarachnoid space, where subarachnoid hemorrhage is most likely. Intervention for symptomatic ICCAAns should be reserved for patients with subarachnoid hemorrhage, epistaxis, severe facial or orbital pain, evidence of radiographic enlargement, progressive ophthalmoplegia, or progressive visual loss.
The Paralysis Associated with Myelomeningocele: Clinical and Experimental Data Implicating a Preventable Spinal Cord Injury
Authors: Heffez Dan S. , Aryanpur John , Hutchins Grover M. , Freeman John M.
Published: April 2011

Paralysis seen in children with myelomeningocele has been attributed to congenital myelodysplasia. We suspected that paralysis may be due in part to a spinal cord injury caused by exposure of the neural tube to the amniotic fluid. This hypothesis was tested using a fetal rat model of surgically created dysraphism. Each pup from the experimental group of rats in which the spinal cord was intentionally exposed to the amniotic fluid was born with severe deformity and weakness of the hind limbs and tail. Control fetal rats, subjected to the same procedure without directly exposing the spinal cord to the intrauterine environment, were normal at birth. Histological studies of the exposed spinal cord revealed extensive erosion and necrosis, findings similar to those described in children with myelomeningocele. We therefore propose a “two-hit” hypothesis to explain the paralysis seen in children with myelomeningocele: congenital myelodysplasia complicated by an intrauterine spinal cord injury. Intrauterine protection of the exposed spinal cord might prevent some or all of the paralysis. The possible implications of these findings for the future treatment of myelomeningocele are discussed.
Intraoperative Localization of a Cervicomedullary Glioma from the Killed End Potential: Illustrative Case
Authors: Morioka Takato , Fujii Kiyotaka , Mitani Masamitsu , Fukui Masashi
Published: April 2011

We recorded the intraoperative somatosensory evoked potentials directly from the upper cervical cord and medulla in a patient with an intrinsic tumor at the region of the cervicomedullary junction. The killed end potential, a large positive potential, was obtained at the caudal end of the tumor. This type of potential occurs when an impulse approaches but never passes beyond the recording electrode. Myelotomy guided by the killed end potential enabled appropriate spinal and medullary dissection and led to early encounter with the cervicomedullary tumor.
Ganglioglioma of the Optic Chiasm: Case Report and Review of the Literature
Authors: Chilton Jonathan , Caughron Michael R. , Kepes John J.
Published: April 2011

We describe a case of ganglioglioma of the optic chiasm and tract in a 33-year-old man. Review of the literature discloses only seven cases of tumors of the anterior visual pathway that meet the histological criteria for such neoplasms. A detailed histological description of our case and a review of the literature is provided.
Symptomatic Arachnoid Cyst at the Clivus Drained Stereotactically through the Vertex
Authors: Iacono Robert P. , Labadie Enrique L. , Johnstone Sharon J. , Bendt Teresa K.
Published: April 2011

A 40-year-old man had an acute ischemic event affecting the pons. He had no cardiac illness or vasculitis and was not diabetic or hypertensive. The contrast-enhanced computed tomographic scan disclosed nothing abnormal, and a vertebral angiogram showed an avascular mass markedly displacing the basilar artery and pons posteriorly and toward the right. A magnetic resonance image clearly delineated a homogeneous arachnoid cyst containing cerebrospinal fluid. To avoid manipulating posterior fossa arteries, after the recent pontine stroke, this arachnoid cyst with unusually favorable anatomical landmarks was approached stereotactically through the vertex. Fenestration and drainage of the cyst was accomplished under local anesthesia and benzodiazepine sedation with low morbidity. The procedure was well tolerated, and the patient returned to gainful employment shortly afterward. He remains asymptomatic at 3 years' follow-up. The successful outcome of this case suggests that in carefully selected symptomatic arachnoid cysts, stereotactic interventions could become a useful surgical alternative. Stereotaxis may also be helpful in other cumbersome surgical cases in which a second port for contrast injection or simple manipulation would be advantageous.
Malignant Teratoma of the Cerebellopontine Angle: Case Report
Authors: İplikçioğlú Celal A. , Özer Fahir , Benli Kemal , Bertan Vural , Ruacan Şevket
Published: April 2011

A case of malignant teratoma of the cerebellopontine angle is presented. Preoperative findings suggested an acoustic neurinoma or a meningioma. Particularly in adulthood, malignant teratomas arising in unusual locations can simulate common intracranial tumors.
Primary T-Cell Lymphoma with Myelopathy Associated with HTLV-1
Authors: Inoue Masaru , Kawaguchi Tsutomu , Yokoyama Hiroaki , Shimada Masahiko
Published: April 2011

The case of a patient who had myelopathy associated with human T-cell lymphotropic virus Type 1 (HTLV-1) for 10 years and developed a T-cell lymphoma in the cerebellum is reported. The relationship between myelopathy associated with HTLV-1 and primary T-cell lymphoma is discussed.
Effect of Nimodipine on Cerebrovascular Response to CO2 in Asymptomatic Individuals and Patients with Subarachnoid Hemorrhage: A Transcranial Doppler Ultrasound Study
Authors: Seiler Rolf W. , Nirkko Arto C.
Published: April 2011

The cerebrovascular response to CO2was evaluated by measuring relative changes in blood flow velocity within the middle cerebral artery by transcranial Doppler ultrasonography during normo-, hypo-, and hypercapnia. In seven patients without subarachnoid hemorrhage (five with unruptured arteriovenous malformations and two with aneurysms), the CO2vasoreactivity was tested on the side of the middle cerebral artery with normal flow velocities opposite the lesion. A baseline CO2reactivity test was obtained in each patient and then repeated under constant intravenous infusion of nimodipine, 2 mg/hr. Nine patients with ruptured aneurysms who were rated at Hunt and Hess Grades 1 or 2 were operated on within 1 to 3 days after the hemorrhage and treated with nimodipine, 2 mg/hr, given intravenously. In these patients. CO2vasoreactivity was tested during the second week after the hemorrhage, when the middle cerebral artery velocity was increased by at least 50% of the initial value or more. Nimodipine was then discontinued and, 48 hours later, when the middle cerebral artery velocity was still in the same range, CO2vasoreactivity was tested again. Two months later, after full recovery from the subarachnoid hemorrhage and normalization of the velocities, a third measurement of CO2reactivity was obtained as a baseline control. No significant effect of nimodipine on CO2vasoreactivity could be demonstrated in any of the test periods. In the second week after a subarachnoid hemorrhage, a significant reduction of the cerebrovascular response to CO2was found (P < 0.005).
Stereotactic Guiding Tube for Open-System Endoscopy: A New Approach for the Stereotactic Endoscopic Resection of Intra-Axial Brain Tumors
Authors: Otsuki Taisuke , Jokura Hidefumi , Yoshimoto Takashi
Published: April 2011

Stereotactic endoscopic resection of intra-axial brain tumors using a newly developed endoscopic system consisting of a stereotactic guiding tube and a fine endoscope is reported. The stereotactically inserted guiding tube acts in the place of brain retractors to expose deep-seated pathological lesions, which are then visualized by means of a fine endoscope. The lesions may then be treated by various microsurgical techniques such as laser vaporization. Fifteen intra-axial lesions were operated on by this method using a guiding tube of 8 mm in outer diameter without significant complications. Seven small lesions measuring 3 to 26 mm in maximal diameter were resected totally. Eight large lesions. including two highly vascularized tumors, were examined by biopsy and resected partially through a burr hole with complete hemostasis under direct vision. This system is particularly useful for removing small intra-axial tumors in deep or eloquent areas difficult to resect using ordinary surgical techniques. It will also be applicable for other stereotactic operations that require accuracy and minimum invasiveness with complete hemostasis under direct visualization.
Thickness of Carotid Artery Atherosclerotic Plaque and Ischemic Risk
Authors: Dempsey Robert J. , Diana Louise A. , Moore Robert W.
Published: April 2011

Noninvasive duplex scanning of carotid artery atherosclerotic plaque was performed in 286 consecutive patients referred to a cerebrovascular diagnostic laboratory. The presence and thickness of such plaque in the region of the carotid bifurcation were examined for association with the degree of vessel stenosis, age, sex, smoking history, history of prior transient ischemic attack or stroke, and systemic manifestations of atherosclerotic disease. Atherosclerotic plaque thickness was positively correlated with degree of vessel stenosis (P< 0.0001). Both parameters were independent predictors of cerebrovascular events but plaque thickness was a better predictor of prior transient ischemic attacks (P<0.05), and vessel stenosis was a better predictor of prior stroke (P<0.005). Patient age (P<0.001) and pack-years of cigarette use (P<0.001) were independent positive predictors of carotid atherosclerotic plaque thickness. The greatest effect of smoking and atherosclerotic plaque thickness was seen in heavy smokers younger than age 55. Both carotid artery plaque thickness and pack-years of smoking were significant independent predictors of other systemic manifestations of atherosclerotic disease (P<0.05). Such noninvasive scanning of carotid artery atherosclerotic plaque demonstrates the significant role of age and smoking in the progression of disease. It also suggests a significant role for carotid atherosclerotic artery plaque in the pathophysiology of cerebrovascular events, especially transient ischemic attacks, even prior to the production of a flow-limiting stenosis. Finally, noninvasive screening of carotid artery plaque may provide a useful marker for the patient at risk for systemic atherosclerotic disease and identify the patient for whom maximal atherosclerotic risk factor modification is needed.
In Vivo Biological Effects of Stereotactic Radiosurgery: A Primate Model
Authors: Lunsford L. Dade , Altschuler Eric M. , Flickinger John C. , Wu Andrew , Martinez Julio A.
Published: April 2011

Single-fraction, closed skull, small-volume irradiation (radiosurgery) of intact intracranial structures requires accurate knowledge of radiation tolerance. We have developed a baboon model to assess the in vivo destructive radiobiological effects of stereotactic radiosurgery. Three baboons received a single-fraction, 150-Gy lesion of the caudate nucleus, the thalamus, or the pons using the 8-mm diameter collimator of the gamma unit. Serial standard neurodiagnostic tests (neurological examination, computed tomographic scan, magnetic resonance imaging, stable xenon-enhanced computed tomographic scan of cerebral blood flow, somatosensory and brain stem evoked potentials, and myelin basic protein levels of cerebrospinal fluid) were compared with preoperative studies. Magnetic resonance imaging revealed the development of a lesion at the target site between 45 and 60 days after irradiation. Deterioration of the brain stem evoked potentials preceded imaging changes when the lesion encroached on auditory pathways. Myelin basic protein levels increased subsequent to imaging changes. Postmortem neuropathological examination confirmed a well-demarcated radionecrosis of the target volume. The baboon model appears to be an excellent method to study the in vivo biological effects of radiosurgery.
Cyst of the Choroid Plexus in the Lateral Ventricle: Case Report and Review of the Literature
Authors: Odake Genya , Tenjin Hiroshi , Murakami Nobukuni
Published: April 2011

We report an intraventricular cyst in a 2-year-old boy who had myoclonic jerks of the extremities. The cyst had no communication with the ventricular system or subarachnoid space. Total removal of the cyst adhering to the choroid plexus was accomplished. The glial cyst wall was lined in part by flattened or cuboidal epithelium. The preoperative and postoperative computed tomographic scans and magnetic resonance images are presented, and congenital benign cysts in the lateral ventricle are reviewed and discussed.
Radical Osteoclastic Craniectomy in Sagittal Synostosis
Authors: Hassler Werner , Zentner Josef
Published: April 2011

We report our experience in the surgical treatment of sagittal synostosis using radical osteoclastic craniectomy in 60 consecutive patients. After surgery in children aged 6 months or younger (Group I), reossification usually started 2 weeks postoperatively and was complete within 6 months, resulting in an optimal skull contour. In children aged 7 to 12 months (Group II), reossification was prolonged and lasted for 12 months or longer. The skull contour normalized in its biparietal width and improved in sagittal diameter, remaining, however, slightly abnormal. In children older than 12 months (Group III), the skull contour partly improved in the biparietal diameter but did not change in the sagittal direction. Reossification was incomplete with persistent pseudosutures. Enlarged frontal subarachnoid spaces were reversible or improved in all patients independent of age at the time of surgery. We encountered no complications in our series. In our opinion, radical osteoclastic craniectomy is the simplest, most efficient, and most physiologically sound method for the treatment of sagittal synostosis in patients up to 6 months of age. This procedure allows the rapidly growing brain to form its skull vault, thus providing optimal cosmetic results. In older children, osteoplastic morcellation procedures should be the treatment of choice.
Distribution of Angiographic Vasospasm after Subarachnoid Hemorrhage: Implications for Diagnosis by Transcranial Doppler Ultrasonography
Authors: Newell David W. , Grady Sean M. , Eskridge Joseph M. , Winn Richard H.
Published: April 2011

A study was undertaken to determine how frequently angiographic vasospasm occurs outside the normal access range of transcranial Doppler ultrasound in patients who have suffered a subarachnoid hemorrhage. Vasospasm located in the basal vessels is readily identifiable using transcranial Doppler ultrasound whereas spasm affecting the more distal, vertically oriented arteries is outside the standard detection range. It is therefore speculated that the sensitivity of the technique would be adversely affected by a high incidence of distal vasospasm. A total of 136 angiograms performed on 68 patients after a subarachnoid hemorrhage from anterior circulation aneurysms were reviewed to determine the typical distribution of vasospasm. Of the 40 cases that showed >25% vessel narrowing, 50.0% had spasm restricted to the basal vessels, 42.5% had spasm involving both basal and distal segments, and 7.5% had spasm of the distal segments only. None of the patients with distal vasospasm alone developed delayed ischemic deficits. It is concluded that most patients with anterior circulation aneurysms who develop vasospasm will have involvement of the basal vessels, but a small number of patients may develop vasospasm only in distal vessels.
Clinicopathological Experience with Pineocytomas: Report of Five Surgically Treated Cases
Authors: Vaquero Jesús , Ramiro Josefa , Martínez Roberto , Coca Santiago , Bravo Gonzalo
Published: April 2011

The clinicopathological experience associated with five cases of pineocytoma is presented. All patients were treated by surgical removal without postoperative radiotherapy. In three individuals, 2000 cGy was administered to the tumor as a presurgical diagnostic test, with no evidence of response. All cases demonstrated histological features of pineocytoma, according to the criteria of Borit et al., and of the so-called “pineocytoma with neuronal differentiation,” according to the criteria of Rubinstein. The experience obtained from the present series reveals that these tumors can occur in the initial decades of life, that a cystic appearance and the presence of calcifications are distinctive features of their radiological evaluation, and that they have a good prognosis after surgical removal, even when the histological data indicate local invasion. The convenience of reserving the term “pineocytoma” for these tumors, and of including the so-called “pineocytomas without further differentiation” within the group of pineoblastomas, is suggested in order to achieve a practical clinicopathological assessment of parenchymatous pineal tumors.
Pituitary Hemorrhage into a Rathke's Cleft Cyst
Authors: Onesti Stephen T. , Wisniewski Thomas , Post Kalmon D.
Published: April 2011

This report describes a case of symptomatic pituitary hemorrhage into a Rathke's cleft cyst in a 25-year-old woman. The literature on pituitary hemorrhage in nonadenomatous sellar tumors is reviewed.
Surgical Outcome in 435 Patients Who Sustained Missile Head Wounds during the Iran-Iraq War
Authors: Aarabi Bizhan
Published: April 2011

Variables important in predicting the final postsurgical outcome of 435 patients who sustained missile head wounds during the Iran-Iraq War were evaluated over a 99-month period. The type of projectile, site of injury, and presence or absence of foreign material did not seem to have a significant effect on the final outcome. Of the patients with a perforating type of injury, 48.8% had a poor surgical outcome as compared with 19.9% with a penetrating type and 15.6% with a tangential type. This difference is statistically significant (x2 = 14.7 and 17.1, respectively; p < 0.001). The most important factor in predicting overall outcome was the Glasgow Coma Scale (GCS) score at the time of admission. Mortality and morbidity contributing to a poor surgical outcome were noted in only 6% of patients with a GCS score at admission of 13 to 15, in 24.6% of those with a GCS score of 9 to 12, in 57% of those with a GCS score of 6 to 8, and in 65% of those with a GCS score of 3 to 5. Of the 71 patients who died, 75% had a score of 3 to 8. Perforating projectiles or those traversing two or more dural compartments were statistically significant in contributing to mortality and moribidity (x2 = 17.2; p < 0.001). The incidence of focal neurological deficit was 100, 90.6, 88, and 52.2% in patients with GCS scores of 3 to 5, 6 to 8, 9 to 12, and 13 to 15, respectively, The two best predictors of mortality in this group of patients were a low GCS score and infection.
Spinal Hemangioblastoma, Syrinx, and Hydrocephalus in a Two-Year-Old Child
Authors: Mock Antonio , Levi Allan , Drake James M.
Published: April 2011

A two-year-old child presented with an acute inability to bear weight. Radiological investigation revealed a large cervicothoracolumbar syrinx of no known cause. During investigation, acute communicating hydrocephalus developed, which required a shunt. At surgery, a small thoracic spinal cord hemangioblastoma was discovered and excised. Complete recovery with collapse of the syrinx followed. The clinical features of this rare childhood tumor and its associated effects are discussed.
Carotid-Cavernous Sinus Fistula Associated with a Primitive Trigeminal Artery
Authors: Cheng Wan-Chun , Wang Alexander Dah-Jium
Published: April 2011

Carotid-cavernous sinus fistulas are not rare, but they have never been reported in association with persistent primitive trigeminal artery. We recently encountered such a case. The Jaeger-Hamby procedure was employed, with mandatory occlusion of the primitive trigeminal artery.
Spinal Cord Blood Flow in the Rat under Normal Physiological Conditions
Authors: Rubinstein Avraham , Arbit Ehud
Published: April 2011

Regional spinal cord blood flow (SCBF) was measured in a group of rats under conditions of normothermia, normocarbia, normoxia, and normal blood pressure, using the hydrogen clearance technique. Regional SCBF in the cervical white matter was 26.8 ± 1 (SE) ml/100 g/min and in the cervical gray matter 53.6 ± 2.5; in the thoracic white matter it was 22.2 ± 2.4 ml/100 g/min and in the thoracic gray matter 41.2 ± 12/6 ml/100 g/min; and in the lumbar gray matter it was 52.3 ± 1.9 ml/100 g/min. The effect of changes in blood pressure on SCBF (autoregulation) was investigated in nine rats. We have observed that SCBF remains relatively constant in the blood pressure range of 45 to 165 mm Hg and assumes a passive flow below or above this range.
Neurinoma in the Cavernous Sinus: Report of Two Cases
Authors: Inoue Tooru , Fukui Masashi , Matsushima Toshio , Hasuo Kanehiro , Matsunaga Masayuki
Published: April 2011

Two cases of trigeminal neurinoma located solely in the cavernous sinus are reported. Preoperatively, magnetic resonance imaging provided the accurate localization of the lesions, allowing precise planning of the surgical approach, that is, a subtemporal lateral approach and a pterional superior approach, respectively. The neurinomas inside the cavernous sinus were removed successfully, and the patients developed no new neurological deficits except for anesthesia in the 1st division of the trigeminal nerve. The characteristic magnetic resonance imaging findings of trigeminal neurinoma in the cavernous sinus are presented, and the different surgical approaches are discussed.
Delayed Hearing Loss after Neurovascular Decompression
Authors: McDonnell Dennis E. , Jabbari Bahman , Spinella Giovana , Mueller Gustave H. , Klara Peter M.
Published: April 2011

We report two unusual cases of delayed hearing loss after neurovascular decompression of structures within the cerebellopontine angle. In the first case, the patient noted a unilateral hearing loss 3 weeks after undergoing vascular decompression of the trigeminal nerve for tic douloureux. This gradually improved over an 18-month period. In the second case, the patient awoke on the 4th day after vascular decompression of the facial nerve for hemifacial spasm with a bilateral hearing loss that has remained unchanged after the onset. These are examples of delayed acoustic dysfunction occurring with a shift in surgically freed vessels and may have been induced by newly directed neurovascular compression or distortion.