bluuebunny/crossref_metadata_2025 huggingface dataset:
Enteral hyperalimentation in head injury
Authors: Clifton Guy L. , Robertson Claudia S. , Contant Charles F.
Published: May 2009

✓ The objectives of this study were to determine the ability of enteral hyperalimentation to meet the caloric and protein requirements in acute severe head injury, and to study the effect of increasing protein intake on nitrogen balance. This consecutive series of 20 patients suffered acute severe head injury and remained comatose for at least 24 hours. They were all without other major injuries, and were treated with steroids. These patients were randomly placed in two comparable treatment groups: one group was fed with an enteral formula containing 14% of its calories as protein and the other group received a formula containing 22% protein calories. Feedings were advanced to replace 140% of caloric expenditure measured by indirect calorimetry, averaging 3500 kcal/24 hr. Balance periods of the targeted intake were 7 days in duration, and were begun during the 1st week after injury for 65% of patients and in the 2nd week after injury for 35% of patients. The lower protein group received an average of 26.8 gm/24 hr of nitrogen, equivalent to 188 gm of protein, and the higher protein group 34.3 gm/24 hr, equivalent to 231 gm of protein. Nitrogen balance was −9.2 ± 6.7 gm/24 hr in the lower protein group and −5.3 ± 5.0 gm/24 hr in the higher protein group, but the difference did not reach statistical significance because of sample size and variability in extent of catabolism among patients. Despite the hyperalimentation, there was a mean negative cumulative nitrogen balance of 200 gm by the 2nd week after injury, and only three patients achieved net nitrogen equilibrium for the 7-day balance period. Despite enteral hyperalimentation, the patients' weight fell by 15% in the 2nd week, serum albumin was often decreased, and creatinine-height index decreased over time but remained in a normal range. Monitoring urinary urea nitrogen, which has been advocated as a generally available technique for measuring urinary nitrogen concentration, was found to be a poor measure of urinary nitrogen excretion. This work has demonstrated: 1) that high caloric and protein feedings may be delivered for prolonged periods enterally for most patients in the acute phase of head injury with few metabolic complications, and 2) that increasing the nitrogen content of feedings from 14% to 22% may somewhat improve nitrogen retention, although nitrogen equilibrium is seldom achieved.
Epidermoid cysts of the posterior fossa
Authors: Berger Mitchel S. , Wilson Charles B.
Published: May 2009

✓ Epidermoid cysts originating in the paramedian basal cisterns of the posterior fossa are congenital lesions that grow to a large size through slow accumulation of desquamated epithelium. These lesions grow between and ultimately displace cranial nerves, vascular structures, and the brain stem, causing a long course of progressive neurological deficits. The onset of symptoms usually occurs during the fourth decade of life. Epidermoid cysts are easily diagnosed with computerized tomography scans, which characteristically show a low-density extra-axial pattern. The primary surgical objective is to decompress the mass by evacuating the cyst contents and removing nonadherent portions of the tumor capsule; portions of the capsule adherent to vital structures should be left undisturbed. Aseptic meningitis is the most common cause of postoperative morbidity, and its incidence may be minimized by intraoperative irrigation with steroids followed by systemic therapy with dexamethasone. Symptomatic recurrences that occur many years after surgery should be managed with conservative reoperation.
Intramedullary spinal cord metastasis
Authors: Costigan Donal A. , Winkelman Marc D.
Published: May 2009

✓ A retrospective autopsy study of 627 patients with systemic cancer disclosed 153 patients with metastasis to the central nervous system (CNS) and 13 patients with intramedullary spinal cord metastasis (ISM). Thus, the frequency of ISM was 8.5% of cases of metastasis to the CNS and 2.1% of all cases of cancer. Bronchogenic carcinoma accounted for 11 cases of ISM, and breast carcinoma and melanoma for the other two. There were two distinct patterns of spinal cord involvement, indicating spread of tumor to the cord by two different routes. In nine of the 13 ISM patients a metastasis was found deep within the spinal cord, unassociated with leptomeningeal carcinomatosis; this most likely resulted from hematogenous spread of tumor from a pulmonary source. In the other four patients there was focal or multifocal direct extension of leptomeningeal metastatic tumor across the pia into the parenchyma of the cord. Only four of the 13 patients had a clinical myelopathy; in three of these four this was the presenting feature of an occult lung cancer.
CT-assisted stereotaxic aspiration of colloid cysts of the third ventricle
Authors: Rivas Juan J. , Lobato Ramiro D.
Published: May 2009

✓ A technique is reported for the stereotaxic evacuation of colloid cysts of the third ventricle using a stereotaxic system adapted for computerized tomography (CT) scanning. This is an accurate, simple, and reproducible method that avoids the risks of direct approaches. Successful intracystic aspiration resulting in the cure of the patient may be difficult when the viscosity of the cyst contents is high. Thus, the authors use a large cannula (1.8 mm in inner diameter) to evacuate cysts that appear hyperdense on CT scans; these seem to contain a thicker colloid material than hypodense or isodense cysts.
Wide variation in risk of wound infection following clean neurosurgery
Authors: Tenney James H. , Vlahov David , Salcman Michael , Ducker Thomas B.
Published: May 2009

✓ The authors have prospectively examined the occurrence of postoperative wound infection following clean neurosurgery in 936 patients. Fewer than 1% received perioperative antibiotic prophylaxis. The overall rate of deep wound infection was 2.6%; no deaths were directly attributable to these infections. Deep wound infections occurred significantly more frequently following craniotomy (4.3%) than following spinal (0.9%) or other clean neurosurgery. Among craniotomies, the deep wound infection rate varied significantly from 11% following repeat operations for recurrent gliomas to 2.5% following non-tumor surgery. Risk of deep wound infection varied more than 11-fold depending on the type of clean neurosurgical operation. It is most feasible to demonstrate the potential efficacy of perioperative antibiotics in clean neurosurgical procedures with the greatest risk of postoperative wound infection. The potential benefit from such prophylaxis would be greatest for patients undergoing these high-risk operations.
Classification and treatment of spontaneous carotid-cavernous sinus fistulas
Authors: Barrow Daniel L. , Spector Robert H. , Braun Ira F. , Landman Jeffrey A. , Tindall Suzie C. , Tindall George T.
Published: May 2009

✓ An anatomical-angiographic classification for carotid-cavernous sinus fistulas is introduced and a series of 14 patients with spontaneous carotid-cavernous sinus fistulas is reviewed to illustrate the usefulness of such a classification for patient evaluation and treatment. Fistulas are divided into four types: Type A are direct high-flow shunts between the internal carotid artery and the cavernous sinus; Type B are dural shunts between meningeal branches of the internal carotid artery and the cavernous sinus; Type C are dural shunts between meningeal branches of the external carotid artery and the cavernous sinus; and Type D are dural shunts between meningeal branches of both the internal and external carotid arteries and the cavernous sinus. The anatomy, clinical manifestations, angiographic evaluation, indications for therapy, and therapeutic options for spontaneous carotid-cavernous sinus fistulas are discussed.
Eosinophil degranulation in the capsule of chronic subdural hematomas
Authors: Yamashima Tetsumori , Kubota Toshihiko , Yamamoto Shinjiro
Published: May 2009

✓ A previously unrecognized role of eosinophils in chronic subdural hematomas is described. Outer membranes of hematomas with marked infiltration by eosinophils were studied ultrastructurally with particular attention to the degranulation of these cells. In all of the five cases studied, degranulation was observed. Disintegration of the cells contributed to the release of granules. The free granules, the matrix of which has been demonstrated to contain plasminogen, were often circulating in the vascular lumen and trapped among the aggregated platelets. They were also found within the fragile vascular wall surrounded by fibrinoid material and in the edematous perivascular interstitium. Some of the perivascular eosinophils showed frank solubilization of granule matrix contents in spite of unaltered crystalloids. These findings suggest a role of eosinophils in the development of local hyperfibrinolysis within the outer membranes, which might contribute to the fluidity of chronic subdural hematomas and the resultant leakage of blood from the vessels in the capsules.
Inhibition of primate spinothalamic tract cells by TENS
Authors: Lee Kyu Ho , Chung Jin Mo , Willis William D.
Published: May 2009

✓ Transcutaneous electrical nerve stimulation (TENS) was applied in an experimental animal model to investigate the underlying mechanisms of this treatment. Recordings were made from identified spinothalamic tract (STT) neurons in the lumbosacral spinal cords of seven anesthetized monkeys. The STT cells were activated by stimulating the common peroneal nerve at a suprathreshold intensity for C-fibers. Evoked responses of C-fibers were compared before, during, and after application of TENS for 5 minutes from a commercially available TENS unit. The current delivered by the TENS unit was monitored.

In 14 STT cells, some degree of inhibition of C-fiber evoked responses occurred only when the intensity of TENS exceeded the threshold of Aδ fibers. At a given stimulus intensity, bursts of pulses repeated at a low rate were more effective than high-rate pulses. When TENS was applied to an area of the skin within a cell's receptive field, it was more effective than when it was applied outside the receptive field. The C-fiber volley recorded from a peripheral nerve was not reduced in size, and there were no substantial changes in its latency due to TENS. The inhibition of the activity of STT cells was not altered appreciably after intravenous injection of naloxone hydrochloride.

These results suggest that TENS produces central nervous system inhibition by activating Aδ afferent fibers. The inhibitory effects of TENS on STT cells appear to be due to a mechanism that does not involve release of endogenous opioid substances.
The ectopic pituitary gland in cases of craniopharyngioma
Authors: Decker Robert E.
Published: May 2009

✓ The author reports two apparently unique cases in which displaced pituitary gland was found at surgery for the resection of a craniopharyngioma. An embryological explanation for this association is proposed.
Transoral transclival removal of a schwannoma anterior to the craniocervical junction
Authors: Crockard H. Alan , Bradford Robert
Published: May 2009

✓ The transoral route was used to remove a schwannoma situated anteriorly at the craniocervical junction. By a relatively simple technique, a watertight closure of the dura and nasopharynx was obtained combined with continuous cerebrospinal fluid (CSF) diversion, first by lumbar drainage and then via a lumboperitoneal shunt. This modification of the standard procedure provides a useful method to prevent CSF fistula formation following transoral intradural surgery.
Transcallosal approach to the contralateral ventricle
Authors: Nehls Daniel G. , Marano Stephen R. , Spetzler Robert F.
Published: May 2009

✓ Recent experience with an intraventricular arteriovenous malformation (AVM) demonstrated the usefulness of a transcallosal approach to the contralateral ventricle. Although this technique provides excellent exposure, its application has not been stressed in the literature. A brief description of the technique and its value is presented.
The natural history of aneurysms and arteriovenous malformations
Authors: Jane John A. , Kassell Neal F. , Torner James C. , Winn H. Richard
Published: May 2009

✓ The authors summarize the findings of previous studies relating to the natural history of aneurysms and arteriovenous malformations (AVM's). Ruptured aneurysms have their highest rate of rebleeding on Day 1, and at least 50% will rebleed during the 6 months after the first hemorrhage. Thereafter, the rate drops to at least 3% a year. This is the same rate as seen in anterior and posterior communicating artery aneurysms treated by anterior cerebral artery clipping and carotid ligation; these operations provide immediate protection but do not result in long-term diminution of the risk of rebleeding. Patients with unruptured incidental and unruptured multiple aneurysms rebleed at a rate of 1% per year, as do patients with subarachnoid hemorrhage of unknown etiology. The risk of rebleeding for AVM's is 3% a year.
Stable xenon CT blood flow mapping for evaluation of patients with extracranial-intracranial bypass surgery
Authors: Yonas Howard , Gur David , Good Barbara C. , Latchaw Richard E. , Wolfson Sidney K. , Good Walter F. , Maitz Glenn S. , Colsher James G. , Barnes J. Edward , Colliander Kristine G. , Teeter Bruce C.
Published: May 2009

✓ Xenon computerized tomography (Xe CT) blood flow studies were conducted in 25 patients referred for a possible extracranial-intracranial bypass procedure for occlusive vascular disease in one or more extra- or intracranial vessels. These studies were helpful in selecting eight candidates for surgery. The Xe CT studies were performed at one or two brain levels using a prototype Xe CT system for measurement of cerebral blood flow which was designed in collaboration with the General Electric Co., and adapted for the GE 9800 scanner. In those patients selected to undergo operation, Xe CT demonstrated compromise of flow reserve regionally, globally, and/or in the watershed area. All eight patients who underwent the procedure showed a favorable clinical response postoperatively, and seven had a dramatic increase in flow. The 17 patients whose baseline CT studies showed no reduction of flow with the Xe CT method were not selected for surgery. All 25 patients have remained neurologically stable to date. Case studies of three of the eight patients undergoing bypass surgery are presented.

This limited but consistent experience suggests that Xe CT blood flow mapping makes possible the recognition of brain regions in which flow reserves are compromised. This is due to the relatively high degree of spatial resolution that this technique provides and to the fact that mapping can be correlated directly with the anatomy. Used in combination with a careful clinical examination and an accurate medical history, this study method appears to be a useful guide in the selection of patients who are most at risk from hemodynamic instability and those who are most likely to benefit from flow-augmentation surgery.
Zygomatic approach for lesions in the interpeduncular cistern
Authors: Fujitsu Kazuhiko , Kuwabara Takeo
Published: May 2009

✓ Lesions in the interpeduncular cistern include basilar tip aneurysms, craniopharyngiomas, and chordomas. The surgical approach to these lesions presents a special technical problem, particularly when they are located high in the interpeduncular fossa. For the purpose of minimizing brain retraction and achieving excellent exposure within the interpeduncular cistern, the authors have developed a new surgical technique which involves detachment of the zygomatic arch.

The patient is placed in the supine position with the head rotated 45° to the contralateral side and tilted down 30° so that the surgeon can see into the interpeduncular cistern obliquely from below. The zygomatic arch of the temporal bone as well as a portion of the lateral orbital rim (the posterior ridge of the frontal process of the zygomatic bone) is removed to expose the anterior temporal base. With posterior retraction of the temporal lobe, the arachnoid membranes covering the Sylvian stem are opened in a retrograde fashion until the tentorial edge is sufficiently exposed. The posterior communicating artery and the optic tract are elevated to enter the interpeduncular cistern, after which the oculomotor nerve is dissected free of its surrounding arachnoid membranes and displaced posteroinferiorly.

Two patients with basilar tip aneurysms were operated on with this zygomatic approach, and a subtemporal modification of the zygomatic approach was used to treat a craniopharyngioma and a chordoma in two other patients. The procedure is described and a short description of its clinical use is given.
Complications of carpal tunnel surgery
Authors: Louis Dean S. , Greene Thomas L. , Noellert Raymond C.
Published: May 2009

✓ During a 12-year period, the authors treated 25 patients with 26 complications of previous carpal tunnel surgery. Twenty-four of these patients were referred following initial surgery elsewhere. The most frequent complication identified was neuroma of the palmar cutaneous branch of the median nerve in 14 of the cases. Other complications were hypertrophic scars, dysesthesias after multiple procedures to release the carpal tunnel, joint stiffness, failure to relieve symptoms, and neuromas of the dorsal sensory branch of the radial nerve. All of these complications are potentially preventable. With a properly placed incision, exposure carried out under magnification, and surgery under direct vision the majority of these complications may be prevented. It is further noted that the technique of transverse incision at the wrist for release of the carpal tunnel is potentially dangerous and should be abandoned.
Isolated ventricles following intraventricular hemorrhage
Authors: Eller Theodore W. , Pasternak Joseph F.
Published: May 2009

✓ Panventricular enlargement often follows intraventricular hemorrhage in the premature neonate. During a recent 12-month period, the authors identified five infants who required shunting because of symptomatic post-hemorrhagic hydrocephalus, which was progressive despite serial lumbar punctures and the use of indwelling subcutaneous ventricular reservoirs. In the first 6 months following placement of the initial shunt, four of the infants required an additional shunt for isolated ventricles. Two children had isolation of the lateral ventricles and required bilateral shunts. Two other children had isolation of the fourth ventricle from the lateral ventricular system and required posterior fossa shunts. All of the children were treated successfully using multiple shunts. In all cases, progressive dilation of the isolated ventricle was unaccompanied by the usual clinical signs of shunt malfunction. It appears that isolated ventricular systems are common following post-hemorrhagic hydrocephalus and these children must be followed closely with ultrasound and computerized tomography scanning.
Thermosensitive determination of obstructed sites in ventriculoperitoneal shunts
Authors: Chiba Yasuhiro , Ishiwata Yusuke , Suzuki Noriyuki , Muramoto Masato , Kunimi Yumiko
Published: May 2009

✓ A simple method is described for checking the patency of ventriculoperitoneal shunts by using a pair of small disc thermistors. With this technique, shunt patency is shown by a downward deflection of the recording trace, blockage of the ventricular catheter is indicated by a flat-line recording, and obstruction of the distal end of the abdominal catheter is demonstrated by an upward deflection. These observations were confirmed in a study of 32 hydrocephalic patients with obstructed shunts who subsequently underwent shuntography and operation. An experimental model was also devised to study the mechanism of the recording changes.
Progressive spasticity and scoliosis in children with myelomeningocele
Authors: Park T. S. , Cail Wayne S. , Maggio William M. , Mitchell Diane C.
Published: May 2009

✓ Seventeen myelodysplastic patients with progressive extremity spasticity and scoliosis underwent radiological evaluation and surgical treatment. All but one were under 18 years of age at the time of surgical treatment. Duration of the clinical presentation ranged from 1½ to 7 years. Metrizamide was instilled into the subarachnoid space in 12 patients, the lateral ventricle in two, and the hydromyelic cavity in three. Sequential computerized tomography scanning after intrathecal instillation of the contrast material clearly demonstrated hydromyelia in nine patients and compression of the brain stem in five. Posterior fossa decompression with plugging of the obex was performed in 12 patients, posterior fossa decompression alone in three, and ventriculoperitoneal (VP) shunting procedures in two. Of the 12 patients who underwent the obex plugging procedures, eight have shown partial or complete resolution of spasticity and an increase in motor strength with no significant postoperative complications. In contrast, posterior fossa decompression or VP shunting procedures alone have not led to a favorable neurological outcome. Hydromyelia may occur more commonly among myelodysplastic patients than previously recognized and may be treated most effectively by the obex plugging procedure.
Pain suppression induced by electrical stimulation of the pontine parabrachial region
Authors: DeSalles Antonio A. F. , Katayama Yoichi , Becker Donald P. , Hayes Ronald L.
Published: May 2009

✓ Cholinergic stimulation by microinjection of drugs into a region surrounding the lateral half of the brachium conjunctivum selectively produces a non-opiate form of pain suppression in the cat. Since this suppression does not appear to involve neural systems that mediate morphine analgesia, stimulation of this pontine parabrachial region (PBR) may potentially be useful for control of human pain resistant or tolerant to opiate treatment. Because of technical problems associated with the clinical use of microinjection techniques in the human brain, we investigated whether electrical stimulation of the PBR can produce pain suppression similar to pain suppression produced by cholinergic stimulation. The results indicate that electrical stimulation of an area generally corresponding to the PBR can also produce significant pain suppression. Although the PBR is a region previously implicated in a variety of behavioral and physiological functions, the stimulation parameters that produce maximal pain suppressive effects (namely, low frequency and relatively low intensity) were not associated with noticeable changes in such functions. The prolonged onset period and persistent analgesic effects outlasting the period of stimulation — features that have been reported in other studies of brain stimulation-produced pain suppression — were observed in the present study. The time course of pain suppression did not parallel other changes in behavioral and physiological functions. These data indicate that electrical stimulation of the PBR, under certain stimulation parameters, can activate previously demonstrated neural populations related to pain suppression without affecting neural elements contributing to other behavioral or physiological functions. The authors suggest that electrical stimulation of the PBR may be clinically applicable for treatment of human pain.
Spontaneous activity of ventral root axons following peripheral nerve injury
Authors: Burchiel Kim J. , Russell Lisa C.
Published: May 2009

✓ In 18 Sprague-Dawley rats, the left sciatic nerve was divided at the mid-femur level. Seven to 9 days later, microfilament recordings were made from the ipsilateral L-5 ventral root. Spontaneous activity in the ventral root, ranging from 0.1 to 6.1 Hz, was recorded in 12 of the 18 animals. Conduction velocity determinations showed this activity to be in A-beta and A-delta fibers. Recordings in 10 normal L-5 ventral roots from five control rats showed no spontaneous activity. In the rats with sciatic nerve division, the ongoing discharge appeared to originate in the cut end of the nerve since mechanical stimulation of the neuroma produced synchronous ventral root activity. Furthermore, cooling of the neuroma inhibited the spontaneous discharge, whereas with rewarming it returned. Spontaneous ventral root activity was also increased by systemic application of epinephrine. This activity was qualitatively similar to spontaneous activity that has been recorded in dorsal root microfilaments after peripheral nerve injury. The observation of an ongoing discharge in potentially nociceptive ventral root axons subsequent to nerve injury may be relevant to the mechanism of chronic pain of peripheral origin.
Histopathological study of major intracranial arteries in premature infants related to intracranial hemorrhage
Authors: Hegedüs Katalin , Molnár Péter
Published: May 2009

✓ The incidence of various types of intracranial hemorrhage (ICH) and the microscopic appearance of the major intracranial arteries were investigated in 112 premature infants, and related to birth weight. In none of the premature newborns, regardless of the presence of ICH, did the intracranial arteries contain true elastic elements. The wall of the basilar artery was significantly thinner in all premature infants with any kind of ICH. Within each body-weight group those with ICH had intracranial arteries with fewer reticular fibers than did those without ICH. The density of the reticular fibers in the cerebral arteries of premature neonates without ICH did not seem to depend on maturity. The authors believe that the hypoplasia of the major intracranial arteries and the reticular fiber deficiency most probably involve the whole vascular system of the brain and may predispose to hemorrhage.
Calf enlargement from S-1 radiculopathy
Authors: Cooper William H. , Ringel Steven P. , Treihaft Marc M. , Hall Karen A.
Published: May 2009

✓ Two patients with painless hypertrophy of one calf had clinical and myelographic features compatible with an S-1 radiculopathy. Electromyographic studies revealed intermittent spontaneous discharges (bizarre repetitive potentials) in the affected extremity. Several patients have previously been described with S-1 radiculopathy and calf hypertrophy with or without spontaneous electrical activity. The hypertrophy in the two present cases could have been caused by continuous stretching (both patients were very active), by the abnormal electrical activity, or by a combination of the two. A neurogenic lesion must be excluded in patients with isolated hypertrophy of a calf muscle, even in the absence of radicular pain.
Giant intradiploic epidermoid cysts of the skull
Authors: Constans Jean Paul , Meder Jean François , De Divitiis Enrico , Donzelli Renato , Maiuri Francesco
Published: May 2009

✓ The authors describe two cases of giant intradiploic epidermoid cysts of the cranial vault in which there was massive intracranial extension causing signs of neurological involvement. The very slow growth and the benign histological nature of these tumors explain their long preoperative evolution and the mild neurological signs in some cases. Roentgenographic and computerized tomography findings permit a correct diagnosis. Complete removal of these cysts and their capsules can be easily accomplished, despite their large size. Total removal of these cysts is associated with a very good long-term prognosis.
Cervical diastematomyelia presenting in adulthood
Authors: Beyerl Brian D. , Ojemann Robert G. , Davis Kenneth R. , Hedley-Whyte E. Tessa , Mayberg Marc R.
Published: May 2009

✓ A case of cervical diastematomyelia in an adult is reported. The patient first noted sensory and motor symptoms at 34 years of age after two episodes of cervical trauma. Metrizamide computerized tomography myelography of the cervical spine and cord showed the region of diastematomyelia and revealed a spur containing both bone and fat tissue projecting into the spinal canal and cord. The spur arose from the laminae and spinous processes of C-2 and C-3, and was successfully excised. Postoperatively, the patient's deficits gradually improved. The literature concerning adult cervical diastematomyelia is reviewed.
Radiation therapy for incompletely resected meningiomas
Authors: Petty Albert M. , Kun Larry E. , Meyer Glenn A.
Published: May 2009

✓ Twelve patients with incompletely resected meningiomas were treated with postoperative radiation therapy. Nine of these patients had previously undergone incomplete surgical resection, and three had suffered one or more postoperative recurrences. The median dose of irradiation was 5490 rads in 6 weeks (range 4800 to 6080 rads). All patients were followed with serial neurological examinations and computerized tomography (CT) scans. Median follow-up period was 54½ months (range 20 to 120 months); 10 of the 12 patients were followed for longer than 42 months posttreatment. Nine patients had no clinical evidence of recurrent disease after radiation therapy, and CT scans confirmed lack of progression or a gradual decrease in tumor size. Three patients had tumor recurrences; two of these lesions appeared at 70 and 112 months after irradiation as extracranial extensions beyond the margin of the irradiation field, and one has exhibited recurrence within the field at 48 months. Three patients who were treated after prior recurrences have demonstrated prolonged progression-free intervals in comparison to the intervals between recurrences prior to irradiation. No significant complications attributable to treatment have been found in any of the patients. These results are discussed in relation to previous reports of the incidence of meningioma recurrence after incomplete resection.
Subependymomas of the fourth ventricle
Authors: Jooma Rashid , Torrens Michael J. , Bradshaw John , Brownell Betty
Published: May 2009

✓ Subependymomas of the fourth ventricle are generally considered incidental postmortem findings, and have received scant attention from neurosurgeons. The authors present a surgical series of 12 cases of this disorder diagnosed over a 13-year period. The clinical and radiological findings were reviewed and correlations made with pathological studies. The subependymoma is a histologically benign tumor that tends to be calcified. It has a predilection for the fourth ventricle and a peak incidence in the fifth decade of life. It is usually of considerable size with extensive attachment at the time of its detection, and is associated with significant surgical morbidity. The authors believe that magnetic resonance imaging may be the best method of investigation. Intraoperative disturbance of circulatory or respiratory control should suggest to the surgeon that the operation be abandoned. A laser or ultrasonic aspirator may be very helpful in removing these tumors. Postoperative care must include monitoring for apnea.
Bypass surgery in patients with intracranial stenotic lesions
Authors: Massimo Collice , Orazio Arena , Felice Filizzolo
Published: May 2009

✓ Postoperative morbidity in patients with intracranial stenotic lesions following extracranial-intracranial arterial (EC-IC) bypass is not well defined. A high rate of neurological complications associated with occlusion of the stenotic arteries after surgery has recently been reported. In the period June, 1976, to March, 1984, the authors performed EC-IC bypass procedures in 19 patients with intracranial stenotic arteries. Most of the patients were initially treated pharmacologically (usually by anticoagulant therapy). Surgery was performed if the symptoms recurred while the patients were under pharmacological treatment and if angiography confirmed arterial stenosis. Antiplatelet therapy was given until the day of surgery and during the entire follow-up period. No permanent postoperative morbidity was observed in the series. One patient, with stenosis of the left siphon, the A1 segment of the anterior cerebral artery, and the M1 segment of the middle cerebral artery, had a transient dysphasia and right hemiparesis (lasting 3 days) in the presence of an unchanged arterial stenosis. In five patients early postoperative angiography (at 5 to 21 days) revealed occlusion of previously stenotic arteries. In one patient the occlusion was disclosed only on a later angiographic study, 2 months after surgery. Although EC-IC bypass is generally not a very high-risk operation in patients with intracranial arterial stenosis, there is a high percentage of immediate postoperative occlusion, and the authors suggest caution in determining indication for surgical treatment.
Regional cerebral blood flow and metabolism in reversible ischemia due to vasospasm
Authors: Powers William J. , Grubb Robert L. , Baker Roy P. , Mintun Mark A. , Raichle Marcus E.
Published: May 2009

✓ Regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of oxygen (rCMRO2) were measured by positron emission tomography (PET) in four patients with subarachnoid hemorrhage and hemiparesis due to cerebral vasospasm. With resolution of the vasospasm, two patients recovered and two remained hemiparetic. Contralateral to the hemiparesis, rCBF was slightly higher in the two patients who eventually recovered (15.0 and 16.2 ml/100 gm/min) than in the two who remained hemiparetic (12.0 and 11.7 ml/100 gm/min). The rCMRO2 measurements showed similar differences, with values of 1.34 and 2.60 ml/100 gm/min in the patients who recovered, and 0.72 and 1.66 ml/100 gm/min in those who did not. These preliminary findings indicate that with PET studies it may be possible to prospectively differentiate patients with neurological deficits due to reversible ischemia from patients with irreversible infarction.
Heparin reduces proliferative angiopathy following subarachnoid hemorrhage in cats
Authors: Kapp John P. , Clower Ben R. , Azar Frederick M. , Yabuno Nobuyoshi , Smith Robert R.
Published: May 2009

✓ Subarachnoid hemorrhage (SAH) was produced in cats by transorbital rupture of the right middle cerebral artery (MCA). In untreated cats, widespread proliferative angiopathy occurred in both MCA's by 16 days after SAH. In cats that received systemic heparin, the pathological events following SAH were clearly reduced in the ruptured artery, and were not present in the contralateral left MCA. Platelets are known to adhere to the subintimal surface of cerebral arteries after SAH. The authors suggest that platelet-derived growth factor released from the intimal platelet carpet following SAH may be the stimulus for the development of proliferative angiopathy, and that this platelet factor is inhibited by heparin.