bluuebunny/crossref_metadata_2025 huggingface dataset:
Cognitive outcome following pallidotomy: the influence of side of surgery and age of patient at disease onset
Authors: Kubu Cynthia S. , Grace Gloria M. , Parrent Andrew G.
Published: May 2009

Object. The authors studied the neuropsychological correlates of stereotactically guided lesioning of the right and left posteroventral globus pallidus internus (GPi) in a prospective series of patients suffering from Parkinson's disease (PD).

Methods. Eighteen patients with PD who underwent stereotactically guided lesioning of the GPi (left side in 10 patients and right side in eight) completed neuropsychological evaluations before and after surgery. Patients served as their own controls. Multiple two-by-two repeated-measures analyses of variance were used to assess neuropsychological changes as a function of the side in which lesioning was performed (lesioning on the left side compared with that on the right) and surgery (presurgery compared with postsurgery). Relationships between cognitive variables and patient age at disease onset, age at surgery, and disease duration were examined using a linear regression model.

The most striking findings were evident from results of a phonemic word fluency test in which patients in whom a left-sided pallidotomy had been performed achieved a mean performance score that was lower than the score of patients in whom a right-sided pallidotomy had been performed; this score declined even more as a result of surgery. Change in performance on the word fluency test across pre- and postoperative assessments was also related to patient age at onset of PD in those who had undergone left-sided pallidotomy, with patients of an older age at disease onset showing the greatest decline in performance.

Conclusions. These preliminary findings indicate that the side on which surgery was performed and patient age at onset of PD are important in the prediction of postoperative cognitive outcome. The findings also indicate that stereotactically guided lesioning of the GPi presents a relatively mild cognitive risk.
Plasma endothelin concentrations after aneurysmal subarachnoid hemorrhage
Authors: Juvela Seppo
Published: May 2009

Object. The pathogenesis of cerebral vasospasm and delayed ischemia after subarachnoid hemorrhage (SAH) seems to be complex. An important mediator of chronic vasospasm may be endothelin (ET), with its powerful and long-lasting vasoconstricting activity. In this study the author investigated the correlation between serial plasma concentrations of ET and ischemic symptoms, angiographically demonstrated evidence of vasospasm, and computerized tomography (CT) findings after aneurysmal SAH.

Methods. Endothelin-1 immunoreactivity in plasma was studied in 70 patients with aneurysmal SAH and in 25 healthy volunteers by using a double-antibody sandwich-enzyme immunoassay (immunometric) technique.

On the whole, mean plasma ET concentrations in patients with SAH (mean ± standard error of mean, 2.1 ± 0.1 pg/ml) did not differ from those of healthy volunteers (1.9 ± 0.2 pg/ml). Endothelin concentrations were significantly higher (p < 0.05) in patients who experienced delayed cerebral ischemia with fixed neurological deficits compared with those in other patients (post-SAH Days 0–5, 3.1 ± 0.8 pg/ml compared with 2.1 ± 0.2 pg/ml; post-SAH Days 6–14, 2.5 ± 0.4 pg/ml compared with 1.9 ± 0.2 pg/ml). Patients with angiographic evidence of severe vasospasm also had significantly (p < 0.05) elevated ET concentrations (post-SAH Days 0–5, 3.2 ± 0.8 pg/ml; post-SAH Days 6–14, 2.7 ± 0.5 pg/ml) as did those with a cerebral infarction larger than a lacuna on the follow-up CT scan (post-SAH Days 0–5, 3.1 ± 0.8 pg/ml; post-SAH Days 6–14, 2.5 ± 0.4 pg/ml) compared with other patients. Patients in whom angiography revealed diffuse moderate-to-severe vasospasm had significantly (p < 0.05) higher ET levels than other patients within 24 hours before or after angiography (2.6 ± 0.3 compared with 1.9 ± 0.2 pg/ml). In addition, patients with a history of hypertension or cigarette smoking experienced cerebral infarctions significantly more often than other patients, although angiography did not demonstrate severe or diffuse vasospasm more often in these patients than in others.

Conclusions. Endothelin concentrations seem to correlate with delayed cerebral ischemia and vasospasm after SAH. The highest levels of ET are predictive of the symptoms of cerebral ischemia and vasospasm, and ET may also worsen ischemia in patients with a history of hypertension. Thus, ET may be an important causal or contributing factor to vasospasm, but its significance in the pathogenesis of vasospasm remains unknown.
Neurosurgical implications of Carney complex
Authors: Watson Joe C. , Stratakis Constantine A. , Bryant-Greenwood Peter K. , Koch Christian A. , Kirschner Lawrence S. , Nguyen Tung , Carney J. Aidan , Oldfield Edward H.
Published: May 2009

Object. The authors present their neurosurgical experience with Carney complex. Carney complex, characterized by spotty skin pigmentation, cardiac myxomas, primary pigmented nodular adrenocortical disease, pituitary tumors, and nerve sheath tumors (NSTs), is a recently described, rare, autosomal-dominant familial syndrome that is relatively unknown to neurosurgeons. Neurosurgery is required to treat pituitary adenomas and a rare NST, the psammomatous melanotic schwannoma (PMS), in patients with Carney complex. Cushing's syndrome, a common component of the complex, is caused by primary pigmented nodular adrenocortical disease and is not secondary to an adrenocorticotropic hormone-secreting pituitary adenoma.

Methods. The authors reviewed 14 cases of Carney complex, five from the literature and nine from their own experience. Of the 14 pituitary adenomas recognized in association with Carney complex, 12 developed growth hormone (GH) hypersecretion (producing gigantism in two patients and acromegaly in 10), and results of immunohistochemical studies in one of the other two were positive for GH. The association of PMSs with Carney complex was established in 1990. Of the reported tumors, 28% were associated with spinal nerve sheaths. The spinal tumors occurred in adults (mean age 32 years, range 18–49 years) who presented with pain and radiculopathy. These NSTs may be malignant (10%) and, as with the cardiac myxomas, are associated with significant rates of morbidity and mortality.

Conclusions. Because of the surgical comorbidity associated with cardiac myxoma and/or Cushing's syndrome, recognition of Carney complex has important implications for perisurgical patient management and family screening. Study of the genetics of Carney complex and of the biological abnormalities associated with the tumors may provide insight into the general pathobiological abnormalities associated with the tumors may provide insight into the general pathobiological features of pituitary adenomas and NSTs.
Paracrine delivery of IL-12 against intracranial 9L gliosarcoma in rats
Authors: Dimeco Francesco , Rhines Laurence D. , Hanes Justin , Tyler Betty M. , Brat Daniel , Torchiana Elena , Guarnieri Michael , Colombo Mario P. , Pardoll Drew M. , Finocchiaro Gaetano , Brem Henry , Olivi Alessandro
Published: May 2009

Object. Interleukin-12 (IL-12) has potential for the treatment of tumors because it can stimulate an antitumor immune response and possesses antiangiogenic properties. In the study reported here, the authors investigated the therapeutic role of locally delivered IL-12 in a malignant brain tumor model.

Methods. After genetically engineering 9L gliosarcoma cells to express IL-12 (9L-IL12 cells), the authors used these cells as a source of locally delivered cytokine. First, they investigated the behavior of these cells, which were implanted with the aid of stereotactic guidance into the rat brain, by using serial magnetic resonance imaging and histopathological examination. Second, they assessed the antitumor efficacy of proliferating, as well as nonproliferating (irradiated), 9L-IL12 cells by implanting these cells in animals challenged by wild-type 9L gliosarcoma (9Lwt) cells. The IL-12 expression in brain regions injected with 9L-IL12 was confirmed by reverse transcription—polymerase chain reaction. Last, the authors explored whether animals treated with 9L-IL12 cells developed an antitumor immunological memory by rechallenging the survivors with a second injection of 9Lwt cells.

The authors demonstrated that local delivery of IL-12 into the rat brain by genetically engineered cells significantly prolongs survival time in animals challenged intracranially with a malignant glioma.

Conclusions. These findings support continued efforts to refine local delivery systems of IL-12 in an attempt to bring this therapy to clinical trials.
Induction of tolerance against ischemia/reperfusion injury in the rat brain by preconditioning with the endotoxin analog diphosphoryl lipid A
Authors: Toyoda Tomikatsu , Kassell Neal F. , Lee Kevin S.
Published: May 2009

Object. Inflammatory responses and oxygen free radicals have increasingly been implicated in the development of ischemic brain injury. In some cases, an attenuation of inflammation or free-radical injury can provide tissue protection. Diphosphoryl lipid A (DPL) is a detoxified derivative of a lipopolysaccharide (endotoxin) of Salmonella minnesota strain R595, which is capable of stimulating the immune system without eliciting direct toxic effects. In this study the authors examined the influence of preconditioning with DPL on ischemia/reperfusion injury in rats.

Methods. Sprague—Dawley rats were injected intravenously with either DPL or vehicle. Twenty-four hours later, some animals were tested for superoxide dismutase (SOD) activity. Others were subjected to a 3-hour period of focal cerebral ischemia and, after a reperfusion period of 24 hours, were killed. Infarction volume, SOD activity, and myeloperoxidase (MPO) activity were assayed in the postischemic animals.

Pretreatment with DPL produced significant reductions in cerebral infarction and MPO activity in the ischemic penumbra. A significant enhancement of basal SOD activity was observed 24 hours after DPL treatment (that is, before ischemia), and a further enhancement of SOD activity was seen in the ischemic penumbra 24 hours after reperfusion.

Conclusions. These data provide the first evidence of a neuroprotective effect of preconditioning with DPL in an in vivo model of cerebral ischemia. Although the precise mechanisms through which DPL exerts its neuroprotective influence remain to be established, an inhibition of the complex inflammatory response to ischemia and an enhancement of endogenous antioxidant activity are leading candidates.
Altered diffusion and perfusion in hydrocephalic rat brain: a magnetic resonance imaging analysis
Authors: Massicotte Eric M. , Buist Richard , Del Bigio Marc R.
Published: May 2009

Object. It can be inferred from data published in the literature that brain compression occurs in the early stages of acute hydrocephalus and that drainage of extracellular waste products is impaired. The authors hypothesized that compression of the cortex would alter water distribution and retard the diffusion of fluid in the hydrocephalic brain.

Methods. Proton diffusion, blood perfusion, and T1 and T2 relaxation times were determined in adult rat brain by using magnetic resonance imaging prior to, and 1 and 8 days after induction of hydrocephalus by kaolin injection. Five anatomical regions of interest were studied. The striatum, dorsal cortex, and lateral cortex exhibited decreased T2 and apparent diffusion coefficient (ADC) values but no change in perfusion. Examination of white matter revealed an initial decrease in ADC followed by a significant increase. The T2 relaxation times increased and perfusion decreased progressively between 1 and 8 days after induction of hydrocephalus.

Conclusions. Acute experimental hydrocephalus causes compression of gray matter, perhaps associated with reduction in total water, which impairs diffusion of water in the tissue. White matter compression and hypoperfusion precede the development of edema. These findings have importance for understanding the neurochemical changes that occur in hydrocephalic brains.
Neuroprotective effects of citicoline on brain edema and blood—brain barrier breakdown after traumatic brain injury
Authors: Başkaya Mustafa K. , Doğan Aclan , Rao A. Muralikrishna , Dempsey Robert J.
Published: May 2009

Object. Cytidine 5′-diphosphocholine (CDPC), or citicoline, is a naturally occurring endogenous compound that has been reported to provide neuroprotective effects after experimental cerebral ischemia. However, in no study has such protection been shown after traumatic brain injury (TBI). In this study the authors examined the effect of CDPC on secondary injury factors, brain edema and blood-brain barrier (BBB) breakdown, after TBI.

Methods. After anesthesia had been induced in Sprague—Dawley rats by using 1.5% halothane, an experimental TBI was created using a controlled cortical impact (CCI) device with a velocity of 3 m/second, resulting in a 2-mm deformation. Four sham-operated control animals used for brain edema and BBB breakdown studies underwent the same surgical procedure, but received no injury. Brain edema was evaluated using the wet—dry method 24 hours postinjury, and BBB breakdown was evaluated by measuring Evans blue dye (EBD) extravasation with fluorescein 6 hours after TBI. The animals received intraperitoneal injections of CDPC (50, 100, or 400 mg/kg two times after TBI [eight–10 animals in each group]) or saline (eight animals) after TBI. Traumatic brain injury induced an increase in the percentage of water content and in EBD extravasation in the injured cortex and the ipsilateral hippocampus. No significant benefit from CDPC treatment was observed at a dose of 50 mg/kg. Cytidine 5′-diphosphocholine at a dose of 100 mg/kg attenuated EBD extravasation in both regions, although it reduced brain edema only in the injured cortex. In both regions, 400 mg/kg of CDPC significantly decreased brain edema and BBB breakdown.

Conclusions. This is the first report in which dose-dependent neuroprotective effects of CDPC have been demonstrated in the injured cortex as well as in the hippocampus, a brain region known to be vulnerable to injury, after experimental TBI. The results of this study suggest that CDPC is an effective neuroprotective agent on secondary injuries that appear following TBI.
Congenital primary cerebral angiosarcoma
Authors: Suzuki Yasuhiro , Yoshida Yasuko K. , Shirane Reizo , Yoshimoto Takashi , Watanabe Mika , Moriya Takuya
Published: May 2009

✓ Reports of angiosarcoma arising in the central nervous system are rare. The authors present the case of a 30-day-old infant with clinical manifestations of projectile vomiting and tense anterior fontanelle resulting from a left frontotemporal tumor. Total excision of this highly vascular, well-circumscribed tumor was performed without incident, and histopathological examination revealed a malignant angiosarcoma. Immunohistochemical reaction of the neoplastic cells was diffusely positive for endothelium-specific antigens including factor VIII-related antigen, CD31, and CD34. The final diagnosis of congenital primary cerebral angiosarcoma was thus confirmed. The patient's postoperative course was uneventful, and he was discharged 2 weeks after the operation. He was in good condition with no sign of recurrence after 11 months; follow-up computerized tomography, magnetic resonance (MR) imaging, and abdominal ultrasonography studies demonstrated no tumor regrowth. The characteristic findings for this tumor on MR imaging, the immunohistochemical findings, and surgical outcome are discussed.
Acute posterior fossa syndrome following lumbar drainage for treatment of suboccipital pseudomeningocele
Authors: Manley Geoffrey T. , Dillon William
Published: May 2009

✓ The authors report on a series of patients who underwent lumbar drainage of cerebrospinal fluid (CSF) for treatment of posterior fossa pseudomeningoceles and who subsequently developed an acute posterior fossa syndrome. These patients were found to have similar radiological findings demonstrating acute mass effect secondary to movement of CSF from the pseudomeningocele into the cerebellar parenchyma. Discontinuation of lumbar drainage resulted in symptomatic and radiological improvement in all patients. From these cases the authors infer that not all pseudomeningoceles communicate directly with the subarachnoid space. A readily recognizable appearance on magnetic resonance imaging that is useful in diagnosing this reversible complication of treatment for posterior fossa pseudomeningocele is also illustrated.
Risk of intraoperative aneurysm clip slippage: a new experience with titanium clips
Authors: Carvi Y Nievas Mario N. , Höllerhage Hans-Georg
Published: May 2009

✓ Slippage of an aneurysm clip as a result of insufficient clip-closing force cannot be predicted, even when using forcetesting devices. Descriptions of intraoperative clip slippages are rarely found in the literature. The authors summarize four unusual cases in which titanium aneurysm clips slipped by a scissorslike mechanism during surgery. They analyze the possible factors implicated in such a dangerous situation and discuss corrective choices.
Patient presentation, angiographic features, and treatment of strangulation-induced dissection of the internal carotid artery
Authors: Malek Adel M. , Higashida Randall T. , Halbach Van V. , Dowd Christopher F. , Phatouros Constantine C. , Lempert Todd E. , Meyers Philip M. , Smith Wade S. , Stoney Ronald
Published: May 2009

✓ Domestic violence leading to strangulation by an abusive spouse can cause carotid artery dissection. This phenomenon is rare and has been described in only three previous instances. The authors present their management strategies in three additional cases.

Three young women aged 24 to 43 years were victims of manual strangulation committed by their spouses 3 months to 1 year before presentation. Two of the patients suffered delayed cerebral infarctions before presentation and angiography demonstrated focal, mirror-image severe residual stenoses in the high-cervical internal carotid artery (ICA), which were characteristic of a healed chronic dissection; there was no evidence of fibromuscular dysplasia. One of these patients underwent unilateral percutaneous angioplasty with stent placement, and the other underwent bilateral percutaneous angioplasty. Both patients have recovered from their strokes and remain clinically stable at 8 and 20 months posttreatment, respectively. The third patient presented with bilateral ischemic frontal watershed infarctions resulting from an occluded left ICA and a severely narrowed right ICA. Given the extent of the established infarctions, this case was managed with a long-term regimen of anticoagulation medications, and the patient remains neurologically impaired.

These cases illustrate the susceptibility of the manually compressed ICA to traumatic injury as a result of domestic violence. They identify bilateral symmetrical ICA dissection as a consistent finding and the real danger of delayed stroke as a consequence of strangulation. Endovascular therapy in which percutaneous angioplasty and/or stent placement are used can be useful in treating residual focal stenoses to improve cerebral perfusion and to lower the risk of embolic or ischemic stroke.
Neural transplantation cannula and microinjector system: experimental and clinical experience
Authors: Mendez Ivar , Hong Murray , Smith Stephen , Dagher Alain , Desrosiers Jacques
Published: May 2009

✓ The authors present a simple, reliable, and safe system for performing neural transplantation in the human brain. The device consists of a transplantation cannula and microinjector system that has been specifically designed to reduce implantation-related trauma and to maximize the number of graft deposits per injection. The system was evaluated first in an experimental rat model of Parkinson's disease (PD). Animals in which transplantation with this system had been performed showed excellent graft survival with minimal trauma to the brain. Following this experimental stage, the cannula and microinjector system were used in eight patients with PD enrolled in the Halifax Neural Transplantation Program who received bilateral putaminal transplants of fetal ventral mesencephalic tissue. A total of 16 transplantation operations and 64 trajectories were performed in the eight patients, and there were no intraoperative or perioperative complications. Magnetic resonance imaging studies obtained 24 hours after surgery revealed no evidence of tissue damage or hemorrhage. Transplant survival was confirmed by fluorodopa positron emission tomography scans obtained 6 and 12 months after surgery.

As neural transplantation procedures for the treatment of neurological conditions evolve, the ability to deliver viable grafts safely will become critically important. The device presented here has proved to be of value in maximizing the number of graft deposits while minimizing implantation-related trauma to the host brain.
Extradural neural axis compartment
Authors: Parkinson Dwight
Published: May 2009

✓ The lengthy, continuous, slender extradural neural axis compartment (EDNAC), which extends from the coccyx to the orbit, has been not so much discovered as recognized. Through this compartment run arteries, myelinated and unmyelinated nerves, and valveless veins. Adipose tissue is abundant in the orbital and spinal segments, possibly due to movement requirements, although it is very sparse in the skull base segment, the last segment to be recognized as a continuation of the EDNAC, which connects Breschet's veins to the orbit. The lateral sellar compartment (in older terminology, the cavernous sinus) is an enlarged segment of this EDNAC along the skull base connecting the orbit with the extradural space through the superior orbital fissure and down the dorsum to Breschet's veins of the basilar process of the occipital bone. Understanding the continuity of the EDNAC should help the student understand any segment, particularly the skull base.

As Batson noted, “Living anatomy is slowly editing and replacing the anatomy of the dead room.”
In vivo assessment of the window of barrier opening after osmotic blood—brain barrier disruption in humans
Authors: Siegal Tali , Rubinstein Rina , Bokstein Felix , Schwartz Allan , Lossos Alexander , Shalom Edna , Chisin Roland , Gomori J. Moshe
Published: May 2009

Object. Osmotic blood—brain barrier (BBB) disruption induced by intraarterial infusion of mannitol is used in conjunction with chemotherapy to treat human brain tumors. The time course to barrier closure, or the so-called therapeutic window, has been examined in animals but little information is available in humans. The authors, therefore assessed the time course to barrier closure after osmotic BBB disruption in humans.

Methods. Disruption of the BBB was demonstrated using 99mTc-glucoheptonate (TcGH) single-photon emission computerized tomography (SPECT) scanning in 12 patients who were treated monthly with combination chemotherapy in conjunction with BBB disruption. The primary diagnosis was primary central nervous system lymphoma in seven patients and primitive neuroectodermal tumors in five. The TcGH (20 mCi) was injected at 1- to 480-minute intervals after osmotic BBB disruption, and patients underwent SPECT scanning after 4 hours. A total of 38 studies was performed. Good-to-excellent BBB disruption was obtained in 29 procedures and poor-to-moderate disruption was seen in the other nine studies.

The TcGH indices correlated with the degree of BBB disruption as measured postprocedure on contrast-enhanced CT scans (r = 0.852). Mean baseline TcGH indices were 1.02 ± 0.07. For the group of patients with good-to-excellent disruptions the mean indices at 1 minute postdisruption measured 2.19 ± 0.18. After 40 minutes no significant change was noted (mean index 2.13 ± 0.2). Then the indices declined more steeply and at 120 minutes after the disruption the index was 1.36 ± 0.02. A very slow decline was noted between 120 and 240 minutes after mannitol infusion. At 240 minutes the barrier was still open for all good-to-excellent disruptions (index 1.33 ± 0.08) but at 480 minutes the mean indices had returned to the baseline level.

Conclusions. Results of these in vivo human studies indicate that the time course to closure of the disrupted BBB for low-molecular-weight complexes is longer than previously estimated. The barrier is widely open during the first 40 minutes after osmotic BBB disruption and returns to baseline levels only after 6 to 8 hours following the induction of good or excellent disruption. These findings have important clinical implications for the design of therapeutic protocols.
Is cerebral perfusion pressure a major determinant of cerebral blood flow during head elevation in comatose patients with severe intracranial lesions?
Authors: Moraine Jean-Jacques , Berré Jacques , Mélot Christian
Published: May 2009

Object. Head elevation as a treatment for lower intracranial pressure (ICP) in patients with intracranial hypertension has been challenged in recent years. Therefore, the authors studied the effect of head position on cerebral hemodynamics in patients with severe head injury.

Methods. The effect of 0°, 15°, 30°, and 45° head elevation on ICP, cerebral blood flow (CBF), systemic arterial (PsaMonro) and jugular bulb (Pj) pressures calibrated to the level of the foramen of Monro, cerebral perfusion pressure (CPP), and the arteriovenous pressure gradient (PsaMonro − Pj) was studied in 37 patients who were comatose due to severe intracranial lesions. The CBF decreased gradually with head elevation from 0 to 45°, from 46.3 ± 4.8 to 28.7 ± 2.3 ml · min−1 · 100 g−1 (mean ± standard error, p < 0.01), and the PsaMonro − Pj from 80 ± 3 to 73 ± 3 mm Hg (p < 0.01). The CPP remained stable between 0° and 30° of head elevation, at 62 ± 3 mm Hg, and decreased from 62 ± 3 to 57 ± 4 mm Hg between 30° and 45° (p < 0.05). A simulation showed that the 38% decrease in CBF between 0° and 45° resulted from PsaMonro − Pj changes for 19% of the decrease, from a diversion of the venous drainage from the internal jugular veins to vertebral venous plexus for 15%, and from CPP changes for 4%.

Conclusions. During head elevation the arteriovenous pressure gradient is the major determinant of CBF. The influence of CPP on CBF decreases from 0 to 45° of head elevation.
Intraparenchymal meningioma originating from underlying meningioangiomatosis
Authors: Mut Melike , Söylemezoğlu Figen , Firat M. Murat , Palaoğlu Selçuk
Published: May 2009

✓ The authors present the case of a 20-year-old woman with right-sided temporal intraparenchymal meningioma originating from underlying meningioangiomatosis. The patient manifested temporal-type seizures as the initial symptom. She had no stigmata of neurofibromatosis Type 2. Neuroradiological studies revealed an intraaxial, contrast-enhancing lesion in the right temporal lobe. After gross-total removal of the tumor, histological examination revealed a transitional meningioma with surrounding neural parenchyma and features of meningioangiomatosis. Although there were no signs of anaplasia, necrosis, or increased mitosis, tumor islands were observed in the adjacent neuropil. The rare association of meningioangiomatosis and meningioma is discussed, along with radiological and surgical findings.
Magnetic resonance appearance of multiple intracranial epidermoid cysts: intrathecal seeding of the cysts?
Authors: Miyagi Yasushi , Suzuki Satoshi O. , Iwaki Toru , Ishido Katsuya , Araki Takehisa , Kamikaseda Kazufumi
Published: May 2009

✓ A 44-year-old man presented to the hospital with multiple intracranial epidermoid cysts. The clinical manifestations of his disease included chronic headaches and one seizurelike episode. Findings determined by magnetic resonance (MR) imaging, surgery, and histological analysis indicated intrathecal and intraventricular seeding of the cysts. Spontaneous (nontraumatic) seeding of multiple daughter cysts from intracranial epidermoid cysts is still very rare and their multiple appearances on MR imaging should be distinguished from the simple scattering of oily contents due to cyst rupture.
Gamma knife radiosurgery for hypothalamic hamartomas in patients with medically intractable epilepsy and precocious puberty
Authors: Unger Frank , Schröttner Oskar , Haselsberger Klaus , Körner Eva , Ploier Robert , Pendl Gerhard
Published: May 2009

✓ Hamartoma of the hypothalamus represents a well-known but rare cause of central precocious puberty and gelastic epilepsy. Due to the delicate site in which the tumor is located, surgery is often unsuccessful and associated with considerable risks. In the two cases presented, gamma knife radiosurgery was applied as a safe and noninvasive alternative to obtain seizure control.

Two patients, a 13-year-old boy and a 6-year-old girl, presented with medically intractable gelastic epilepsy and increasing episodes of secondary generalized seizures. Abnormal behavior and precocious puberty were also evident. Magnetic resonance (MR) imaging revealed hypothalamic hamartomas measuring 13 and 11 mm, respectively. After general anesthesia had been induced in the patients, radiosurgical treatment was performed with margin doses of 12 Gy to 90% and 60% of isodose areas, covering volumes of 700 and 500 mm3, respectively.

After follow-up periods of 54 months in the boy and 36 months in the girl, progressive decrease in both seizure frequency and intensity was noted (Engel outcome scores IIa and IIIa, respectively). Both patients are currently able to attend public school. Follow-up MR imaging has not revealed significant changes in the sizes of the lesions.

Gamma knife radiosurgery can be an effective and safe treatment modality for achieving good seizure control in patients with hypothalamic hamartomas.
Gamma surgery for vestibular schwannoma
Authors: Prasad Dheerendra , Steiner Melita , Steiner Ladislau
Published: May 2009

Object. The goal of this study was to assess the results of gamma surgery (GS) for vestibular schwannoma (VS) in 200 cases treated over the last 10 years and to review the role of this neurosurgical procedure in the management of VS.

Methods. Follow-up reviews ranging from 1 to 10 years were available in 153 of these patients. Follow-up images in these cases were analyzed using computer software that we developed to obtain volume measurements for the tumors, and the clinical condition of the patients was assessed using questionnaires.

Gamma surgery was the primary treatment modality in 96 cases and followed microsurgery in 57 cases. Tumors ranged in volume from 0.02 to 18.3 cm3. In the group in which GS was the primary treatment, a decrease in volume was observed in 78 cases (81%), no change in 12 (12%), and an increase in volume in six cases (6%). The decrease was more than 75% in seven cases. In the group treated following microsurgery, a decrease in volume was observed in 37 cases (65%), no change in 14 (25%), and an increase in volume in six (11%). The decrease was more than 75% in eight cases. Five patients experienced trigeminal dysfunction; in three cases this was transient and in the other two it was persistent, although there has been improvement. Three patients had facial paresis (in one case this was transient, lasting 6 weeks; in one case there was 80% recovery at 18 months posttreatment; and in one case surgery was performed after the onset of facial paresis for presumed increase in tumor size). Over a 6-year period, hearing deteriorated in 60% of the patients. Three patients showed an improvement in hearing. No hearing deterioration was observed during the first 2 years of follow-up review.

Conclusions. Gamma surgery should be used to treat postoperative residual tumors as well as tumors in patients with medical conditions that preclude surgery. Microsurgery should be performed whenever a surgeon is confident of extirpating the tumor with a risk—benefit ratio superior to that presented in this study.
Neuroprotective effect of postischemic administration of progesterone in spontaneously hypertensive rats with focal cerebral ischemia
Authors: Kumon Yoshiaki , Kim Soon C. , Tompkins Paul , Stevens Alan , Sakaki Saburo , Loftus Christopher M.
Published: May 2009

Object. Exogenous progesterone has been shown to reduce brain edema and ischemia-induced cell damage and to improve physiological and neurological function during the early stage of focal cerebral ischemia. In the present study, the authors assessed the neuroprotective potential of progesterone during the late stage of ischemia in a transient middle cerebral artery (MCA) occlusion model in the rat.

Methods. Forty-eight male spontaneously hypertensive rats were randomly assigned to six groups. Progesterone was dissolved in dimethyl sulfoxide (DMSO). In four groups of rats, the dissolved progesterone (4 mg/kg or 8 mg/kg) was administered for 2 or 7 days after ischemia. In two control groups DMSO was administered for 2 or 7 days after ischemia. Occlusion of the MCA was induced by insertion of an intraluminal suture, and reperfusion was accomplished by withdrawal of the suture. Treatment was initiated on reperfusion, which followed 2 hours of MCA occlusion, and continued once a day. Lesion volume, neurological deficit, and body weight loss were measured 2 or 7 days after ischemia, depending on the animal group.

Treatment with a high dose of progesterone (8 mg/kg) resulted in reductions in lesion size, neurological deficits, and body weight, compared with control rats.

Conclusions. Administration of progesterone to male rats 2 hours after MCA occlusion reduces ischemic brain damage and improves neurological deficit even 7 days after ischemia.
Enhancement of survival of stored dopaminergic cells and promotion of graft survival by exposure of human fetal nigral tissue to glial cell line—derived neurotrophic factor in patients with Parkinson's disease
Authors: Mendez Ivar , Dagher Alain , Hong Murray , Hebb Adam , Gaudet Paula , Law Adam , Weerasinghe Swarna , King David , Desrosiers Jacques , Darvesh Sultan , Acorn Tanya , Robertson Harold
Published: May 2009

✓ The authors have studied the ability of glial cell line—derived neurotrophic factor (GDNF) to promote survival of human fetal dopaminergic tissue after a storage period of 6 days and subsequent implantation into the human putamen. The results indicate that GDNF promotes survival of stored dopaminergic cells. Cells stored without GDNF had a 30.1% decrease in survival time compared with those exposed to GDNF. Two patients with Parkinson's disease received bilateral putaminal implants of fetal dopaminergic cells exposed to GDNF for 6 days and showed enhancement of graft survival as assessed by positron emission tomography scanning. A mean increase of 107% in putaminal fluorodopa uptake from baseline values was observed 12 months postgrafting.
Use of gadolinium as an intraarterial contrast agent in digital subtraction angiography of the cervical carotid arteries and intracranial circulation
Authors: Nussbaum Eric S. , Casey Sean O. , Sebring Leslie A. , Madison Michael T.
Published: May 2009

✓ Patients with renal insufficiency or other contraindications to iodine-based contrast agents present a significant management dilemma when conventional arteriography is required. The authors describe the use of gadolinium as an alternative contrast agent for arterial digital subtraction (DS) angiography of the cervical carotid arteries (CAs) and intracranial circulation.

Three patients with renal insufficiency presented with symptoms of ischemic cerebrovascular disease and inconclusive noninvasive imaging studies, which necessitated conventional angiography. Traditional transfemoral catheterization of the cervical CAs was performed and DS angiographic studies were obtained using gadolinium as an intraarterial contrast agent. In one case, selective arteriographic examination of the internal carotid arteries and vertebrobasilar system was performed as well. High-quality, diagnostic images essentially indistinguishable from routine angiographic studies were obtained in all cases. No patient suffered a complication related to the use of gadolinium, and no patient demonstrated worsened renal function after the procedure.

In the setting of a contraindication to iodine-based contrast agents, gadolinium represents an important alternative contrast material that allows for excellent visualization of the cervical CAs and intracranial circulation.
Seven years of clinical experience with the programmable Codman Hakim valve: a retrospective study of 583 patients
Authors: Zemack Göran , Romner Bertil
Published: May 2009

Object. The goal of this study was to assess the value of the Codman Hakim programmable valve to settings in the range of 30 to 200 mm H2O. This valve can be adjusted noninvasively for cerebrospinal fluid (CSF) drainage.

Methods. The authors conducted a single-center retrospective study of 583 patients (421 adults and 162 children) suffering from hydrocephalus of various causes (379 patients), normal-pressure hydrocephalus (174 patients), arachnoid cyst (14 patients), and pseudotumor cerebri (16 patients). In all cases a Codman Hakim programmable valve was implanted; in 82.8% of cases it was included during the patient's first shunt implantation.

In 42.4% of the cases valve pressure adjustment was required at least once (mean number of adjustments 1.2, maximum 23). The patients' clinical status improved after 64.6% of pressure adjustments. Accidental resetting of opening pressure, other than that caused by magnetic resonance (MR) imaging, was uncommon. Because MR imaging caused resetting in 26.8% of cases in which it was used, it was deemed mandatory to obtain an x-ray film after MR imaging. Valve malfunction, blockage, or adjustment difficulties occurred in 2% of valves implanted, and nontraumatic subdural fluid collections were demonstrated in 5.1% of patients (13 of whom were treated by valve pressure adjustment alone). Five-year shunt survival was 53.1% for first-time shunt implantations. The shunt infection rate was 8.5% of valve implantations. Catheter-related complications and shunt-related infections were the main reasons for surgical revision and the major cause of shunt failure. At follow-up review, 97% of children and 90% of adults had improved.

Conclusions. Because one cannot know in advance which case will turn out to be complicated, the authors' preference is to use the Codman Hakim programmable valve for all conditions in which CSF should be drained.
Improvement in cerebral blood flow and metabolism following subarachnoid hemorrhage in response to prophylactic administration of the hydroxyl radical scavenger, AVS, (±)-N,N′-propylenedinicotinamide: a positron emission tomography study in rats
Authors: Yamamoto Seiji , Teng Weiyu , Nishizawa Shigeru , Kakiuchi Takeharu , Tsukada Hideo
Published: May 2009

Object. The hydroxyl radical scavenger (±)-N,N′-propylenedinicotinamide (AVS) has been shown to ameliorate the occurrence of vasospasm following experimental subarachnoid hemorrhage (SAH) and to reduce the incidence of delayed ischemic neurological deficits (DINDs) in patients with SAH. The authors investigated whether prophylactic administration of AVS could improve cerebral blood flow (CBF) and cerebral glucose utilization (CGU) following SAH in rats.

Methods. Anesthetized rats were subjected to intracisternal injection of blood (SAH group) or saline (control group). Either AVS (1 mg/kg/min) or saline (vehicle group) was continuously injected into the rat femoral vein. Forty-eight hours later, positron emission tomography scanning was used with the tracers 15O-H2O and 18F-2-fluoro-d-glucose to analyze quantitatively CBF and CGU, respectively, in the frontoparietal and occipital regions (12 regions of interest/group).

In SAH rats receiving only vehicle, CBF decreased significantly (p < 0.05, Tukey's test) and CGU tended to decrease, compared with values obtained in control (non-SAH) rats receiving vehicle. In rats that were subjected to SAH, administration of AVS significantly (p < 0.05, Tukey's test) improved CBF and CGU in both the frontoparietal and occipital regions compared with administration of vehicle alone.

Conclusions. Prophylactic administration of AVS improves CBF and CGU in the rat brain subjected to SAH, and can be a good pharmacological treatment for the prevention of DINDs following SAH.
Complement activation in the brain after experimental intracerebral hemorrhage
Authors: Hua Ya , Xi Guohua , Keep Richard F. , Hoff Julian T.
Published: May 2009

Object. Brain edema formation following intracerebral hemorrhage (ICH) appears to be partly related to erythrocyte lysis and hemoglobin release. Erythrocyte lysis may be mediated by the complement cascade, which then triggers parenchymal injury. In this study the authors examine whether the complement cascade is activated after ICH and whether inhibition of complement attenuates brain edema around the hematoma.

Methods. This study was divided into three parts. In the first part, 100 µl of autologous blood was infused into the rats' right basal ganglia, and the animals were killed at 24 and 72 hours after intracerebral infusion. Their brains were tested for complement factors C9, C3d, and clusterin (a naturally occurring complement inhibitor) by using immunohistochemical analysis. In the second part of the study, the rats were killed at 24 or 72 hours after injection of 100 µl of blood. The C9 and clusterin proteins were quantitated using Western blot analysis. In the third part, the rats received either 100 µl of blood or 100 µl of blood plus 10 µg of N-acetylheparin (a complement activation inhibitor). Then they were killed 24 or 72 hours later for measurement of brain water and ion contents. It was demonstrated on Western blot analysis that there had been a sixfold increase in C9 around the hematoma 24 hours after the infusion of 100 µl of autologous blood. Marked perihematomal C9 immunoreactivity was detected at 72 hours. Clusterin also increased after ICH and was expressed in neurons 72 hours later. The addition of N-acetylheparin significantly reduced brain edema formation in the ipsilateral basal ganglia at 24 hours (78.5 ± 0.5% compared with 81.6 ± 0.8% in control animals, p < 0.001) and at 72 hours (80.9 ± 2.2% compared with 83.6 ± 0.9% in control animals, p < 0.05) after ICH.

Conclusions. It was found that ICH causes complement activation in the brain. Activation of complement and the formation of membrane attack complex contributes to brain edema formation after ICH. Blocking the complement cascade could be an important step in the therapy for ICH.
Neuroendoscopic aqueductal stent placement procedure for isolated fourth ventricle after ventricular shunt placement
Authors: Shin Masahiro , Morita Akio , Asano Shuichiro , Ueki Keisuke , Kirino Takaaki
Published: May 2009

✓ Isolated fourth ventricle (IFV) is a rare complication in patients who undergo shunt placement, and it is not easily corrected by surgical procedures. The authors report a case of IFV that was successfully treated with an aqueductal stent placed under direct visualization by using a neuroendoscope. This 36-year-old suffered meningitis after partial resection of a brainstem pilocytic astrocytoma, and subsequently developed hydrocephalus for which a ventriculoperitoneal shunt was placed. Nine months later, the patient presented with progressive cerebellar ataxia, and magnetic resonance imaging revealed slitlike supratentorial ventricles and a markedly enlarged fourth ventricle, which were compatible with the diagnosis of IFV. The surgical procedure described was performed under visualization through a styletlike slim optic fiberscope inserted into a ventricular catheter. The catheter, with the endoscope inside it, was passed through the foramen of Monro and then through the aqueduct to reach the enlarged fourth ventricle, where membranous occlusion of the foramen of Magendie was clearly visualized. The tip of the catheter was placed in the fastigium of the fourth ventricle. After the procedure, the size of the fourth ventricle was reduced and the patient's symptoms improved. Thus, it is concluded that endoscopic aqueductal stent placement is a simple and safe surgical procedure for treatment of IFV.
Flushing in relation to a possible rise in intracranial pressure: documentation of an unusual clinical sign
Authors: Hornig Gregory W.
Published: May 2009

✓ This report documents clinical features in five children who developed transient reddening of the skin (epidermal flushing) in association with acute elevations in intracranial pressure (ICP). Four boys and one girl (ages 9–15 years) deteriorated acutely secondary to intracranial hypertension ranging from 30 to 80 mm Hg in the four documented cases. Two patients suffered from ventriculoperitoneal shunt malfunctions, one had diffuse cerebral edema secondary to traumatic brain injury, one was found to have pneumococcal meningitis and hydrocephalus, and one suffered an intraventricular hemorrhage and hydrocephalus intraoperatively. All patients were noted to have developed epidermal flushing involving either the upper chest, face, or arms during their period of neurological deterioration. The response was transient, typically lasting 5 to 15 minutes, and dissipated quickly. The flushing reaction is postulated to be a centrally mediated response to sudden elevations in ICP. Several potential mechanisms are discussed. Flushing has clinical importance because it may indicate significant elevations in ICP when it is associated with neurological deterioration. Because of its transient nature, the importance of epidermal flushing is often unrecognized; its presence confirms the need for urgent treatment.
Selective transvenous liquid embolization of a Type 1 dural arteriovenous fistula at the junction of the transverse and sigmoid sinuses
Authors: Ohtakara Kazuhiro , Murao Kenichi , Kawaguchi Kenji , Kuga Yoshihiro , Kojima Tadashi , Taki Waro , Waga Shiro
Published: May 2009

✓ The authors describe the case of a 51-year-old man with a Type 1 dural arteriovenous fistula (AVF) located at the junction of the transverse and sigmoid sinuses. The dural AVF developed after the patient underwent a craniotomy for an acute extradural hematoma. The patient suffered pulsatile tinnitus 3 months after surgery. After several attempts at transarterial embolization (TAE), the venous channel located close to the skull fracture was accessed via a transfemoral—transvenous approach and was embolized by administering a liquid nonadhesive agent. Successful embolization of the dural AVF was achieved both clinically and radiologically without causing considerable hemodynamic alterations. This procedure, either alone or combined with TAE, would seem to be an alternative treatment for dural AVFs in this location, without causing compromise of flow within the affected sinuses, when selective venous access is available.
Modified stereotactic insertion of the Ommaya reservoir
Authors: Al-Anazi Abdul , Bernstein Mark
Published: May 2009

✓ Ommaya reservoirs are used primarily for the repeated injection of intrathecal chemotherapy for leptomeningeal metastasis from hematopoietic and solid malignancies. Insertion of this device in a relatively large nondisplaced ventricle is not a difficult task, but challenges arise when the ventricle is small and/or displaced. Different techniques have been developed to overcome this difficulty, most of which include the use of stereotactic frames. Further improvements would be beneficial.

The technique described in this paper depends on a stereotactic frame; however, the modification proposed by the authors removes the arc system from the surgical field before the actual surgical procedure is begun. Removal of the arc improves access to the surgical field as well as preparation and draping of the surgical site and minimizes potential breaks in sterile technique, which ultimately reduces the incidence of infection. A twist-drill hole along the path of the chosen trajectory becomes an external guide for the ventricular catheter. The technique is easy, user friendly, and results in an unencumbered sterile field and reliable cannulation of small ventricles.

A simple stereotactic technique for Ommaya reservoir insertion has been described. It should lower the chance of infection in this group of patients, most of whom have suppressed immune systems.