bluuebunny/crossref_metadata_2025 huggingface dataset:
Resection for solitary brain metastasis
Authors: Smalley Stephen R. , Laws Edward R. , O'Fallon Judith R. , Shaw Edward G. , Schray Mark F.
Published: May 2009

✓ The authors reviewed 229 consecutive patients treated intramurally by resection of solitary cerebral metastasis. Patients were classified into four groups on the basis of whether a gross total resection or subtotal resection was performed and whether systemic disease was present or absent at the time of craniotomy. Group 1 had gross total resection and no systemic disease; Group 2 had subtotal resection and no systemic disease; Group 3 had subtotal resection and systemic disease; and Group 4 had gross total resection and systemic disease. All four groups were further subdivided into Subgroup A (adjuvant whole-brain radiation therapy) or Subgroup B (no adjuvant radiation). Data were collected regarding multiple patient and tumor variables for multivariate analysis. Survival data for the 46 patients in Group 1A (median 1.3 years, 2-year survival rate 41%, 5-year survival rate 21%) were markedly better than those for the 75 in Group IB (median 0.7 year, 2-year survival rate 19%, 5-year survival rate 4%). The 20 patients in Group 2A also had superior survival data (median 1.1 years, 2-year survival rate 30%, 3-year survival rate 30%) when compared with the eight patients in Group 2B (median 3 months, 1-year survival rate 0%). However, the 16 and 22 patients in Groups 3A and 4A, respectively, had no discernible differences compared to the seven and 35 patients in their Group 3B and 4B counterparts. Multivariate analyses were performed to assess the association of survival with multiple patient, disease, and treatment variables. Poor neurological status and systemic disease were significantly associated with inferior survival, while longer (> 36 months) intervals between primary diagnosis and craniotomy were significantly associated with improved survival. After adjusting for the effects of other patient, disease, and treatment characteristics, adjuvant whole-brain radiotherapy was significantly associated with improved survival times. These data support the continued use of craniotomy followed by adjuvant wholebrain radiation therapy for treatment of solitary brain metastasis. However, this aggressive therapy appears relatively contraindicated in the face of either systemic disease or substantial neurological deficit.
Intracavitary brachytherapy of cystic craniopharyngiomas
Authors: van den Berge J. Herbert , Blaauw Gerhard , Breeman Wout A. P. , Rahmy Ali , Wijngaarde Rinia
Published: May 2009

✓ Visual function, endocrinological status, and radiological outcome are reported in 31 patients harboring a cystic craniopharyngioma, who underwent 35 intracavitary brachytherapy procedures with yttrium-90. In 26 of these patients intracavitary brachytherapy was the primary treatment. The follow-up period ranged from 2 to 80 months (41 ± 22 months, mean ± standard deviation). Five patients died from tumor-related causes. Endocrine recovery was modest.

Prior to brachytherapy, visual acuity was diminished in 38 eyes and field defects were present in 46. Funduscopy before treatment revealed optic atrophy in 47% of the eyes. Visual acuity improved in 29% of the eyes studied, remained stable in 13%, and deteriorated in 58%. Visual field defects improved in 28% of the eyes studied, remained stable in 20%, and deteriorated in 52%. The possible causes for deterioration in visual function are discussed.

Complete resolution of 10 cysts was noted. In 12 patients the size of the cyst decreased; however, in three of these patients new cyst formation took place. The cyst size stabilized in six cases and increased in three. Although there is still a substantial degree of visual function deterioration following intracavitary brachytherapy, morbidity is otherwise low, making this treatment modality a reasonable alternative to craniotomy.
Aggravation of vasogenic cerebral edema by multiple-dose mannitol
Authors: Kaufmann Anthony M. , Cardoso Erico R.
Published: May 2009

✓ The authors investigated the pharmacokinetics of mannitol administered for treatment of vasogenic cerebral edema. A cortical cold injury was produced in 23 cats maintained under general anesthesia for 5 or 21 hours. Control animals received no mannitol, while treatment groups received either a single dose or five doses administered at 4-hour intervals of 0.33 gm/kg radiolabeled mannitol. Liquid scintillation counting was carried out to determine the concentrations of mannitol in the cerebral tissue, cerebrospinal fluid, plasma, and urine. Cerebral water content and linear progression of edema were also measured.

Rapid plasma clearance prevented accumulation of mannitol after multiple intravenous injections, as 84% ± 2% (mean ± standard error of the mean) of the infused mannitol was excreted through the urine. However, there was progressive accumulation of mannitol within the cerebral tissue, especially in the edematous white matter where it reached a level of 0.33 ± 0.03 mg/gm after five doses, exceeding the trough plasma concentrations by a ratio of 2.69:1. Water content measurement showed that a single dose of mannitol failed to reduce cerebral water content or edema progression at 4 hours postinjection, while multiple doses produced a 3% increase in water content in edematous regions (p > 0.0003). The results of this study demonstrated a reversal of the osmotic concentration gradient between edematous brain and plasma following multiple mannitol injections, associated with exacerbation of vasogenic cerebral edema.
Mononuclear leukocyte ADP-ribosylation as an indicator of immune function in malignant-glioma patients treated with betamethasone for cerebral edema
Authors: Pero Ronald W. , Salford Leif G. , Strömblad Lars-Göran , Andersson Christina
Published: May 2009

✓ Glioma patients receiving corticosteroids (16 mg/day betamethasone) were examined for evidence of immune cell dysfunction by using quantitative estimates of adenosine diphosphate (ADP)-ribosylation in peripheral mononuclear leukocytes as the physiological indicator. The duration of daily treatment with corticosteroids varied from 0 to 35 days at the time of collection of the blood samples. Even after adjustment for covariate factors such as age, sex, smoking habits, alcohol use, antiepileptic medications, and tumor grade, there still remained a highly significant dose-dependent inverse relationship between constitutive and hydrogen peroxide-induced mononuclear leukocyte ADP-ribosylation levels and the duration of corticosteroid treatment (beta coefficients −0.40 and −0.29, respectively; p < 0.03). No other variable under consideration significantly influenced ADP-ribosylation levels after statistical adjustment. These data support a mutual interdependence of mononuclear leukocyte ADP-ribosylation and corticosteroid-induced immune cell dysfunctionin vivo.
Intracranial lipoma associated with cerebral saccular aneurysm
Authors: Futami Kazuya , Kimura Akira , Yamashita Junkoh
Published: May 2009

✓ The authors present a case of lipoma in the sylvian fissure associated with a saccular aneurysm of the middle cerebral artery. The aneurysm was successfully clipped following the partial resection of the tumor. This is the first reported case of this combined pathology. The value of cerebral angiography in this disease entity and the possible etiology of the association of an aneurysm with a lipoma are discussed.
Hospital of the University of Pennsylvania
Authors: Langfitt Thomas W.
Published: May 2009

✓s The Hospital of the University of Pennsylvania was the first university-owned teaching hospital in the nation. The author briefly reviews its history and association with the other faculties of the University.
Seizure outcome in patients with surgically treated cerebral arteriovenous malformations
Authors: Piepgras David G. , Sundt Thoralf M. , Ragoonwansi Ashvin T. , Stevens Lorna
Published: May 2009

✓ A series of 280 cases of cerebral arteriovenous malformations (AVM's) treated surgically between June, 1970, and June, 1989, is reviewed with particular focus on the preoperative seizure history and follow-up seizure status. Follow-up evaluation (mean duration 7.5 years) was achieved in 98% of cases and was accomplished through re-examinations, telephone interviews, and written questionnaires. Overall, 89% of the surviving patients with a follow-up period of greater than 2 years were free of seizures at last examination.

Of the 280 patients in this series. 163 had experienced no seizures preoperatively. A recent follow-up study (with a minimum duration of 2 years or to death) was available in 157 of these 163 cases; 21 patients had died. Of the 136 surviving patients, only eight (6%) were having new ongoing seizures. In the 128 (94%) who had remained seizure-free, 73% were receiving no anticonvulsant agents while 27% were taking anticonvulsant prophylaxis. The 2-year minimum follow-up study in 110 of the 117 patients with preoperative seizures revealed that eight (7%) had died. Of the 102 surviving patients, 85 (83%) were seizure-free (with 48% no longer receiving anticonvulsant therapy), while 17 (17%) still suffered intermittent seizures. However, of these 17 patients, 13 reported their seizures to be improved compared to preoperatively; the seizures were the same in two patients and were worse in two patients.

An actuarial analysis was conducted comparing the life expectancy of patients following surgery for AVM's with the expected survival of a general white population of the same age and sex in the West Northcentral region of the United States. No statistically significant difference was found. There were seven perioperative deaths (three from cerebral hemorrhage, two from pulmonary emboli, and two from obstruction of venous drainage) and 22 deaths during the follow-up period. Of these 22 deaths, the cause was unknown in four patients, apparently unrelated to the AVM in 13, and directly or indirectly related to the patient's neurological condition prior to surgery or due to surgery performed for resection of the AVM in five.

There was a statistically significant relationship between the size and location of the AVM and the clinical presentation. Patients with small AVM's (< 3 cm) were more likely to present with hemorrhage whereas those with large AVM's were more likely to present with seizures.

Conclusions from this study are: 1) there is a low incidence of a new seizure disorder following surgery: 2) chances for resolution or control of a pre-existing seizure disorder are good: 3) although resolution of seizures or seizure control was achieved postoperatively in AVM's of all sizes, this benefit was highest in smaller as opposed to larger AVM's; and 4) ultimately, there is a good capacity for recovery from pre-existing neurological deficits or those resulting from surgery.
Control of temporal lobe epilepsy following en bloc resection of low-grade tumors
Authors: Kirkpatrick Peter J. , Honavar Minal , Janota Ivan , Polkey Charles E.
Published: May 2009

✓ Thirty-one patients with a mean age of 18.9 years (range 3 to 53 years) who underwent temporal lobe surgery for tumor-related epilepsy over a 14-year period are presented. All had suffered chronic drug-resistant temporal lobe seizures (mean age at onset 6.9 years, range 0 to 30 years; mean duration of condition 11.9 years, range 3 to 39 years). Preoperative interictal scalp electroencephalography tracings indicated unilateral localized epileptic foci in 90% of patients, and computerized tomography scans showed abnormalities within the temporal lobe in 87%. All patients underwent en bloc temporal lobectomy. No patient received adjuvant radiotherapy or chemotherapy. Review of the histological material showed dysembryoplastic neuroepithelial tumor in 27 (87%) of the specimens and microscopic evidence of incomplete removal of tumor in 22 (71%). At long-term follow-up evaluation (mean duration 5.8 years, range 1 to 14 years), 81% of patients were completely free of seizures (Engel grade I) and 10% were almost seizure free (Engel grade II) with no deaths reported in either early or late follow-up review. Only one patient in the series failed to benefit from the surgery. Four patients suffered permanent neurological deficit causing a mild disability. Psychological assessment showed no significant fall in verbal or performance intelligent quotient for the group, but a mild memory impairment was evident in 32%. Behavioral and social aspects improved in nearly all (94%) cases. Relief of seizures could not be predicted by intraoperative electrocorticography, and outcome was independent of the completeness of tumor resection. Postoperative electroencephalographic findings identified epileptiform potentials in 65% of patients, which were associated with a worse seizure-control outcome grade.
Odontoid fractures in elderly patients
Authors: Hanigan William C. , Powell Frank C. , Elwood Patrick W. , Henderson John P.
Published: May 2009

✓ This retrospective analysis describes the clinical characteristics, treatment, and outcome of 19 patients aged 80 years or older with odontoid fractures. The fractures were due to falls in 15 patients (78.9%) and were associated with motor-vehicle accidents in four. Type III fractures were seen in three patients and type II fractures in 16. No patient suffered a neurological injury associated with the fracture. Five patients (26.3%) died during hospitalization; factors contributing to their death included prolonged bed rest, associated injuries, and concomitant medical illnesses. The mean follow-up period in the remaining 14 patients was 28.8 months (range 5 to 72 months). Eight patients with a posterior displacement of 5 mm or less were treated with cervical immobilization, three of whom showed a stable non-union of the fracture site at follow-up review. One patient with 10-mm displacement refused operative treatment. Three of the patients without surgical treatment subsequently died from unrelated causes; all remaining patients resumed their routine activity. Five patients with displacement of 5 mm or greater and instability at the fracture site were treated with posterior cervical fusion of C1–2 using wire and autologous iliac bone grafts. In this group, no operative morbidity or mortality occurred and stable constructs developed in all patients; one patient died from an unrelated cause during the follow-up period and the other patients resumed their normal activity. Prolonged bed rest caused respiratory complications in two of six patients who survived initial hospitalization; two of three patients treated with rigid immobilization developed complications that required alternative treatments.
Treatment of spasmodic torticollis with intradural selective rhizotomies
Authors: Friedman Allan H. , Nashold Blaine S. , Sharp Robbin , Caputi Franco , Arruda Jose
Published: May 2009

✓ To determine the effects of ventral cervical and selective spinal accessory nerve rhizotomy on spasmodic torticollis, 58 patients who had undergone surgery between 1979 and 1987 were reviewed retrospectively. At the time of surgery, each nerve rootlet was electrically stimulated to determine its effect on the nuchal musculature prior to sectioning. Forty-nine patients (85%) had a marked improvement in their condition, with 33 (57%) attaining an excellent result and 16 (28%) noting significant improvement. Patients complained of abnormal head posture, nuchal muscle spasms, and pain prior to surgery. Muscle spasms were completely relieved in 42 patients (72%) and markedly reduced in 10 (17%). Of the 47 patients with preoperative pain, 30 (64%) were free of their pain and eight (17%) noted that the pain was reduced in intensity and frequency. Thirty-four patients (59%) reported that their resting head posture was restored to a neutral position. The likelihood that a patient's head posture returned to normal was inversely proportional to the preoperative duration of the spasmodic torticollis. Twenty-six patients (45%) suffered mild transient difficulty with swallowing solid foods in the immediate postoperative period. In most cases these minor difficulties abated in the months following surgery.
Comparison of regeneration across nerve allografts with temporary or continuous cyclosporin A immunosuppression
Authors: Midha Rajiv , Mackinnon Susan E. , Evans Peter J. , Best Timothy J. , Hare Gregory M. T. , Hunter Dan A. , Falk-Wade Judy A.
Published: May 2009

✓ The efficacy of short-term immunosuppression in a nerve allograft model was examined by comparing regeneration across peripheral nerve allografts with either temporary (12 weeks) or continuous (30 weeks) cyclosporin A treatment. One-hundred fifty Lewis rats received 2-cm nerve grafts from allogeneic ACI or syngeneic Lewis rat donors and were allocated to the following groups: allogeneic grafts and continuous cyclosporin A, with 18 weeks (20 rats) or 30 weeks (20 rats) of survival after graft placement; allogeneic grafts and temporary cyclosporin A, with 12 weeks (10 rats), 18 weeks (20 rats), or 30 weeks (20 rats) of survival; and control rats with allogeneic and syngeneic grafts, no cyclosporin A, with 12, 18, or 30 weeks (10 rats each) of survival. Functional regeneration across the nerve grafts was serially assessed with walking-track analysis. Endpoint evaluations included electrophysiological, histological, and morphometric studies.

Both walking-track and electrophysiological function reached a plateau at a significantly worse level in nonimmunosuppressed allograft recipients than in syngeneic or treated allograft recipients. The group with temporary therapy experienced significant worsening in both motor and electrophysiological function at Week 18, 6 weeks after cyclosporin A withdrawal, compared to the group with continuous treatment. At Week 30, motor and electrophysiological function in the temporary-treatment group recovered to levels similar to those of the syngeneic and continuous cyclosporin A groups. Histological assessment of the graft segments from the temporary cyclosporin A group at 18 weeks showed evidence of rejection, with mononuclear cell infiltration and demyelination; morphometric evaluation demonstrated significantly decreased numbers of nerve fibers in the distal host segment. These histological and morphometric changes were no longer present in the nerves from the temporarily immunosuppressed rats at Week 30.

Withdrawal of immunosuppression after successful regeneration through nerve allografts results in short-term graft rejection. Eventual restoration of graft histological and function parameters is comparable to continuously immunosuppressed rats. Temporary immunosuppression of nerve allograft recipients is feasible.
Implantation of intracerebral depth electrodes for monitoring seizures using the Pelorus stereotactic system guided by magnetic resonance imaging
Authors: Yeh Hwa-Shain , Taha Jamal M. , Tobler William D.
Published: May 2009

✓ The Pelorus stereotactic system guided by magnetic resonance imaging was used to implant intracerebral depth electrodes for monitoring seizure activity. This stereotactic system is frameless and does not require the use of a computer. It is based on the concept of a ball-and-socket type stereotactic arc director and uses the center-of-arc principle to establish a trajectory for electrode placement. The system not only allows the use of the orthogonal approach, but also provides ample working space and flexibility to choose different entry points and trajectory angles.
Occlusive hyperemia: a theory for the hemodynamic complications following resection of intracerebral arteriovenous malformations
Authors: Al-Rodhan Nayef R. F. , Sundt Thoralf M. , Piepgras David G. , Nichols Douglas A. , Rßfenacht Daniel , Stevens Lorna N.
Published: May 2009

✓ An alternative theory is proposed to explain the brain edema and hemorrhage that may occur after resection of high-flow intracerebral arteriovenous malformations (AVM's). This theory, termed “occlusive hyperemia,” is based on a retrospective analysis of operative dictations along with postoperative imaging studies (191 angiograms and 273 computerized tomography scans) in 295 cases of intracerebral AVM's operated on at the Mayo Clinic between 1970 and 1990. In this series, 34 cases (12%) of postoperative deterioration were documented, of which 15 were due to incomplete resection of the AVM. Of the remaining 19 cases, six had brain edema alone and 13 had hemorrhage with edema, despite complete excision of the AVM. In these 19 cases, the AVM's were greater than 6 cm in diameter in 10 patients, between 3 and 6 cm in six, and less than 3 cm in three. Obstruction of the venous drainage system was observed in 14 (74%) of the 19 cases. Ten of these 14 were due to obstruction of the primary venous drainage of the brain parenchyma immediately surrounding the lesions, while four were due to obstruction of other venous structures. In no case was a rapid circulation identified on postoperative angiograms. The flow pattern was slow or stagnant in former AVM feeders and their parenchymal branches. It is proposed that postoperative intracranial hemorrhage and/or brain edema in AVM patients may be due to: 1) obstruction of the venous outflow system of brain adjacent to the AVM, with subsequent passive hyperemia and engorgement; and 2) stagnant arterial flow in former AVM feeders and their parenchymal branches, with subsequent worsening of the existing hypoperfusion, ischemia, and hemorrhage or edema into these areas. Supportive hemodynamic evidence for this theory was derived from the literature.
Intrathecal baclofen for intractable spasticity of spinal origin: results of a long-term multicenter study
Authors: Coffey Robert J. , Cahill David , Steers William , Park T. S. , Ordia Joe , Meythaler Jay , Herman Richard , Shetter Andrew G. , Levy Robert , Gill Brian , Smith Richard , Wilberger Jack , Loeser John D. , Chabal Charles , Feler Claudio , Robertson James T. , Penn Richard D. , Clarke Aiden , Burchiel Kim J. , Leibrock Lyal G.
Published: May 2009

✓ A total of 93 patients with intractable spasticity due to either spinal cord injury (59 cases), multiple sclerosis (31 cases), or other spinal pathology (three cases) were entered into a randomized double-blind placebocontrolled screening protocol of intrathecal baclofen test injections. Of the 88 patients who responded to an intrathecal bolus of 50, 75, or 100 µg of baclofen, 75 underwent implantation of a programmable pump system for chronic therapy. Patients were followed for 5 to 41 months after surgery (mean 19 months). No deaths or new permanent neurological deficits occurred as a result of surgery or chronic intrathecal baclofen administration. Rigidity was reduced from a mean preoperative Ashworth scale score of 3.9 to a mean postoperative score of 1.7. Muscle spasms were reduced from a mean preoperative score of 3.1 (on a fourpoint scale) to a mean postoperative score of 1.0. Although the dose of intrathecal baclofen required to control spasticity increased with time, drug tolerance was not a limiting factor in this study. Only one patient withdrew from the study because of a late surgical complication (pump pocket infection). Another patient received an intrathecal baclofen overdose because of a human error in programming the pump. The results of this study indicate that intrathecal baclofen infusion can be safe and effective for the long-term treatment of intractable spasticity in patients with spinal cord injury or multiple sclerosis.
Human-specific c-neu proto-oncogene protein overexpression in human malignant astrocytomas before and after xenografting
Authors: Bernstein Jerald J. , Anagnostopoulos Anna V. , Hattwick Emily A. , Laws Edward R.
Published: May 2009

✓ Overexpression of human-specific c-neu proto-oncogene transmembrane tyrosine kinase receptor protein (p185) is an index of cell transformation and of poor patient survival in several malignancies. The authors studied this protein in low- and high-grade human malignant astrocytomas before and after xenografting into aspiration pockets in rat cortex. Human-specific p185c-neu-positive cells were found in tumor specimens from all grades of astrocytoma. Significantly fewer p185c-neu-positive cells were observed in the low-grade versus the high-grade astrocytomas examined (p < 0.05). Human specific p185c-neu-positive cells were also positive for the human major histocompatibility complex, human leukocyte antigen (HLA)-DR, as well as glial fibrillary acidic protein and S-100 protein. Fresh suspensions of tumor tissue were prelabeled with the plant lectin Phaseolus vulgaris leukoagglutinin and xenografted into pockets in rat cortex. A class of human p185c-neu-positive cells found in tissue samples from all grades of astrocytoma migrated in the rat brain along parallel and intersecting nerve fiber bundles and basement membrane-lined surfaces. Migrated p185c-neu-positive cells were also positive for HLA-DR, Phaseolus vulgaris leukoagglutinin, glial fibrillary acidic protein, and S-100 protein, suggesting that they were in fact human astrocytoma cells. Simultaneous expression of human p185c-neu, HLA-DR, and glial fibrillary acidic protein was observed in a class of human malignant astrocytoma cells in both tumor tissue and xenografted cells that migrated into rat brain. These molecules are signature proteins for the study of the spread of human malignant astrocytomas in an animal model, and indicate that transformed human malignant astrocytoma cells can migrate within the parenchyma of the central nervous system and could play a role in the development of multifocal tumors.
Reinforced cytotoxicity of lymphokine-activated killer cells toward glioma cells by transfection with the tumor necrosis factor-α gene
Authors: Tashiro Takashi , Yoshida Jun , Mizuno Masaaki , Sugita Kenichiro
Published: May 2009

✓ Lymphokine-activated killer (LAK) cells generated from peripheral blood lymphocytes incubated with recombinant interleukin-2 were transfected with the human tumor necrosis factor (TNF)-α gene by means of novel liposomes with a positive change on their surface. The cells secreted significant amounts of TNF-α into the culture medium and exhibited reinforcement of cytotoxicity toward a human glioma cell line (U251-SP), being three times more cytotoxic than nontransfected LAK cells. The mechanism for the reinforcement of cytotoxicity is considered to involve not only an increase in TNF-α secretion from LAK cells but also its expression on their surface. Intratumoral or intrathecal injection of LAK cells transfected with the TNF-α gene may be useful for the treatment of patients with malignant gliomas.
Contributions of ions and albumin to the formation and resolution of ischemic brain edema
Authors: Menzies Stephen A. , Betz A. Lorris , Hoff Julian T.
Published: May 2009

✓ Changes in brain water, sodium, potassium, and albumin contents and blood-brain barrier (BBB) permeability were determined at various times between 1 hour and 6 weeks following occlusion of the middle cerebral artery (MCA) in rats. In the center of the infarct, brain edema increased to a maximum level by 12 hours, remained elevated for 7 days, and then returned to normal. The change in water content was accompanied by a parallel increase in sodium and decrease in potassium contents; however, the increase in sodium always exceeded the decrease in potassium, resulting in a net gain in brain cations during edema formation which returned to normal with edema resolution. The BBB permeability to 3H-α-aminoisobutyric acid was increased by 24 hours after MCA occlusion and returned to normal by 1 week after the edema had resolved. The time course for changes in brain albumin content was different than that for brain edema formation. Large increases in brain albumin content were not apparent until 6 hours after the onset of ischemia, rose to a peak at 3 days after occlusion of the MCA, and returned to normal several weeks after the edema had resolved. Albumin appeared to spread from the central infarct zone to surrounding, less ischemic areas. The relative contributions of the osmotic force produced by the increase in brain cations and the oncotic force produced by the increase in brain albumin to the observed change in water content were calculated. At all time points, the increase in brain cations accounted for nearly all of the observed brain edema, while the increase in albumin played essentially no role in edema development.
Chronic motor cortex stimulation in patients with thalamic pain
Authors: Tsubokawa Takashi , Katayama Yoichi , Yamamoto Takamitsu , Hirayama Teruyasu , Koyama Seigou
Published: May 2009

✓ Analysis of the authors' experience over the last 10 years has indicated that excellent pain control has rarely been obtained by thalamic relay nucleus stimulation in patients with thalamic pain. In the present study, 11 patients with thalamic pain were treated by chronic stimulation of the precentral gyrus. In eight patients (73%), the stimulation system was internalized since excellent pain control was achieved during a 1-week test period of precentral gyrus stimulation. In contrast, no clear effect was noted or the original pain was even exacerbated by postcentral gyrus stimulation. The effect of precentral stimulation was unchanged in five patients (45%) for follow-up periods of more than 2 years. In the remaining three patients, the effect decreased gradually over several months. This outcome was significantly better than that obtained in an earlier series tested by the authors with thalamic relay nucleus stimulation (p < 0.05). The pain inhibition usually occurred at intensities below the threshold for production of muscle contraction (pulse duration 0.1 to 0.5 msec, intensity 3 to 8 V). When good pain inhibition was achieved, the patients reported a slight tingling or mild vibration sensation during stimulation projected in the same area of distribution as their pain.

The authors discuss the possibility that, in deafferentation pain, sensory neurons below the level of deafferentation cannot exert their normal inhibitory influences toward deafferented nociceptive neurons because of the development of aberrant connections. Thus, while stimulation of the first- to third-order sensory neurons at the level of the thalamic relay nucleus or below cannot bring about good pain inhibition in patients with thalamic pain, activation of hypothetical fourth-order sensory neurons through precentral stimulation may be able to inhibit deafferented nociceptive neurons within the cortex. None of the patients developed either observable or electroencephalographic seizure activity.
Differentiating solitary small cysticercus granulomas and tuberculomas in patients with epilepsy
Authors: Rajshekhar Vedantam , Haran R. P. , Prakash G. Shankar , Chandy Mathew J.
Published: May 2009

✓ It is commonly believed that differentiating solitary small cysticercus granulomas and small tuberculomas in patients with seizures is difficult without resorting to an excision biopsy. The aim of this study was to formulate clinical and computerized tomography (CT) criteria to distinguish these two entities in patients with epilepsy. Toward this end, clinical and CT data from six consecutive patients with histologically proven small solitary tuberculomas and 25 consecutive patients with histologically proven solitary cysticercus granulomas were compared. Evidence of raised intracranial tension and a progressive focal neurological deficit was seen only in patients with tuberculomas (two of six cases). All tuberculomas were greater than 20 mm in size and five of the six were irregular in outline. Only tuberculomas were associated with a midline shift on CT (four of six cases). All cysticercus granulomas were less than 20 mm in size and 24 (96%) of the 25 were regular in outline, conforming to one of two characteristic patterns. No cysticercus granuloma was associated with a midline shift. Based on the above clinical findings (evidence of raised intracranial tension and a progressive neurological deficit) and CT criteria (size, shape, and association with a midline shift), it is possible to separate these two entities in a majority of patients with seizures and with a single small lesion on CT.
Conventional radiation therapy of intracranial arteriovenous malformations: long-term results
Authors: Redekop Gary J. , Elisevich Kost V. , Gaspar Laurie E. , Wiese Karen P. , Drake Charles G.
Published: May 2009

✓ Conventional radiation therapy has been used in the treatment of arteriovenous malformations (AVM's) for many years, but there are limited data pertaining to specific treatment parameters, long-term results, and complications. Between 1955 and 1985, 15 patients with AVM's deemed inoperable or incompletely obliterated using surgical or endovascular techniques were treated at the University of Western Ontario. There were nine males and six females, aged 15 to 48 years (mean 29 years). Presenting symptoms included hemorrhage in nine patients, seizures in four, and focal neurological deficits in two. There were three infratentorial and 12 supratentorial AVM's, ranging in size from 1.5 to 6.5 cm. Therapy prior to irradiation consisted of incomplete surgical removal in four cases and subtotal embolization in four. One patient received 2000 cGy of irradiation, while 4000 to 5000 cGy were delivered in the remaining patients to fields ranging in size from 4 × 4 to 14 × 14 cm in 15 to 28 fractions. The 15 patients have been followed for 1½ to 21 years since undergoing radiotherapy (mean 8.1 years). Angiography in 12 patients at 1 to 21 years following irradiation demonstrated no significant change in seven patients, a slight reduction in AVM size in two, near-complete obliteration in one, and complete obliteration in two. One patient with an AVM measuring 6.5 cm refused angiography but underwent magnetic resonance imaging at 5 years which showed no evidence of residual AVM. There were four hemorrhages in 122 patient-years of follow-up study, indicating a hemorrhage rate of 3.3% per year. The authors conclude that conventional irradiation is successful in obliterating AVM's in only about 20% of cases.
Intracranial complications of hypervolemic therapy in patients with a delayed ischemic deficit attributed to vasospasm
Authors: Shimoda Masami , Oda Shinri , Tsugane Ryuichi , Sato Osamu
Published: May 2009

✓ This investigation has revealed the frequency of various intracranial complications that may result from hypervolemic therapy for a delayed ischemic deficit following subarachnoid hemorrhage (SAH). Among 323 patients with SAH, 112 patients developed a delayed ischemic deficit, 94 of whom underwent hypervolemic therapy. Infarction due to vasospasm was found ultimately in 43 of these 94 patients. Twenty-six patients (28%) developed an intracranial complication during hypervolemic therapy: cerebral edema was aggravated in 18, and a hemorrhagic infarction developed in eight. In 13 of 18 patients with aggravation of edema, delayed ischemic deficit developed within 6 days after the SAH; at that time, a massive new infarction was found in four and edema in 10 patients. After hypervolemic therapy, the 18 patients with aggravation of edema deteriorated rapidly, and 14 of them died. In every case in which hemorrhagic infarction followed hypervolemic therapy, a new infarct was found on computerized tomography (CT) when the delayed ischemic deficit became apparent. Hemorrhagic infarction developed as the delayed ischemic deficit resolved, with one exception. In patients who sustained no complication from hypervolemia, the incidence of both massive new infarction and edema at the time when the delayed ischemic deficit was manifested was only 1%. In 44 of 68 patients who sustained no complication from hypervolemia, the delayed ischemic deficit was manifested on or after the 7th day following the SAH. This study suggests that hypervolemic therapy is contraindicated in a patient who is found to have a massive abnormality on CT at the time when a delayed ischemic deficit is manifested, especially when it occurs within 6 days after the SAH. To avoid hemorrhagic infarction, it is important to discontinue hypervolemic therapy as soon as the delayed ischemic deficit resolves.
Inhibition of angiogenesis and growth of human nerve-sheath tumors by AGM-1470
Authors: Takamiya Yoshiaki , Friedlander Robert M. , Brem Harold , Malick Amy , Martuza Robert L.
Published: May 2009

✓ The effectiveness of AGM-1470, a potent, fungal-derived inhibitor of angiogenesis, in suppressing the neovascularization and growth of human Schwann cell tumors was tested in six schwannomas, seven neurofibromas, and one neurofibrosarcoma. Tumor fragments from surgical specimens were implanted into the subrenal capsule of 348 nude mice (nu/nu). Seven days after implantation, the tumors were measured and vascularity was graded. The animals were then randomly assigned to one of two groups, to receive either saline (control group) or systemic AGM-1470 treatment. After 2 to 6 weeks of treatment, tumor size and degree of vascularity were recorded. In the six different schwannomas implanted into 138 mice, the average vascular grade in the control group after 2 weeks of treatment increased from 2.2 to 3.2 (+1.0), while in the AGM-1470-treated group it decreased from 2.2 to 1.7 (−0.5) (p < 0.01). In the seven different neurofibromas implanted into 158 mice, the change in the average vascular grade in control and AGM-1470-treated animals was +0.5 and −1.0, respectively (p < 0.01). In the one neurofibrosarcoma implanted into 52 mice, the change in average vascular grade in each group during the 6-week treatment period was +1.9 and −1.0, respectively (p < 0.01). Neurofibrosarcoma growth after 6 weeks of AGM-1470 treatment was only 8.5% of the growth found in the control animals (p < 0.01). This study determined that AGM-1470 is effective in inhibiting angiogenesis and the growth of human nerve-sheath tumors.
Use of the excimer laser in high-flow bypass surgery of the brain
Authors: Tulleken Cornelis A. F. , Verdaasdonk Ruud M. , Berendsen Wim , Mali W. P. T. M.
Published: May 2009

✓ The technique of laser-assisted anastomosis for high-flow bypass surgery using the excimer laser is described in 15 rabbits and in one patient. The left common carotid artery of the rabbits was excised and, with two anastomoses, connected to the right common carotid artery. An end-to-side anastomosis technique was used that obviated the temporary occlusion of the recipient artery. The end of the donor artery was connected for its full circumference with the exterior of the recipient artery and, with the aid of an excimer laser catheter (introduced via an artificial side branch of the donor artery), the wall of the recipient artery was evaporated. In two animals only, occlusion of the anastomosis sites occurred. In the remaining 13 animals both anastomosis sites were proven to be patent by inspection at different times, followed by scanning electron microscopy in six animals.

In a patient with hypoperfusion of the brain caused by bilateral internal carotid artery occlusion, revascularization of the right hemisphere was obtained by placing a shunt between the proximal superficial temporal artery and the intracranial portion of the internal carotid artery, using a free transplant of the right inferior epigastric artery. The anastomosis with the internal carotid artery was created using the excimer laser-assisted technique without occlusion of the recipient artery.
Histological studies of intracranial vessels in primates following transluminal angioplasty for vasospasm
Authors: Kobayashi Hidenori , Ide Hisashi , Aradachi Hiroshi , Arai Yoshikazu , Handa Yuji , Kubota Toshihiko
Published: May 2009

✓ Percutaneous transluminal angioplasty for treatment of cerebral vasospasm was performed in primates. Chronic cerebral vasospasm was induced by placement of an autologous blood clot over the right internal carotid artery (ICA), middle cerebral artery (MCA), and anterior cerebral artery (ACA). Cerebral angiography on Day 7 showed that the diameters of the ICA, MCA, and ACA were reduced to 55.7% ± 1.3%, 55.3% ± 2.6%, and 59.6% ± 1.3%, respectively, of baseline. The angioplasty was carried out with a silicone microballoon attached to a microcatheter under somatosensory evoked potential (SEP) monitoring on Day 7. The angioplasty for ICA was performed satisfactorily; however, the balloon could be not advanced to the spastic M1 or A1 portions of the cerebral artery. Following angioplasty, the diameters of the ICA, the M1 segment, and the A1 segment were 79.6% ± 2.9% (p < 0.001), 67.6% ± 4.3% (p < 0.05), and 61.7% ± 2.2% (not significant), respectively, of baseline. Histological studies demonstrated that the vessels were well dilated and patent without endothelial cell damage.
Spontaneous temporal encephalocele
Authors: Wilkins Robert H. , Radtke Rodney A. , Burger Peter C.
Published: May 2009

✓ The authors report a 36-year-old woman with a 23-year history of simple and complex partial seizures who was treated surgically for an anteroinferior temporal encephalocele, with resolution of the seizure disorder. This patient's presentation, findings, and response to treatment are typical of those associated with anteroinferior temporal encephalocele, and different from the clinical patterns of four other types of spontaneous temporal encephalocele.
Intraoperative localization using an armless, frameless stereotactic wand
Authors: Barnett Gene H. , Kormos Donald W. , Steiner Charles P. , Weisenberger Joe
Published: May 2009

✓ A technique of “frameless” stereotaxy that allows real-time intraoperative neurosurgical localization is described. The system is composed of four components: a hand-held probe containing two ultrasonic emitters, a microphone array that is rigidly affixed to the operating table in proximity to the surgical field, hardware to control and detect timing of signal production and reception, and a color graphics computer workstation with software to calculate and present the location of the probe tip on reconstructed neuroimaging studies. Unlike previously reported mechanical or sonic navigational devices, this system is adaptable to a wide array of neurosurgical instruments, allows free movement of the operating table and conventional patient draping, and has accuracy in the hostile operating room environment that rivals that of frame stereotaxy.

In the operating room environment, using four pulse pairs with the wand positioned optimally, reproducibility of a point in space is ± 0.6 mm. The wand has a broad range of orientations that maintain error at or below 1.0 mm. The mean error when measuring distances within a 1000-cu cm cube is 1.1 ± 1.0 mm (1.0% ± 0.7%). The ability to localize a fourth point (a target) in space is typically within 1.5 mm (using computerized tomography scans with a 1-mm slice thickness) but is dependent on several variables. This technology provides a powerful yet flexible tool in the neurosurgical operating room.
Tonsillar herniation: the rule rather than the exception after lumboperitoneal shunting in the pediatric population
Authors: Chumas Paul D. , Armstrong Derek C. , Drake James M. , Kulkarni Abhaya V. , Hoffman Harold J. , Humphreys Robin P. , Rutka James T. , Hendrick E. Bruce
Published: May 2009

✓ Although the development of tonsillar herniation (acquired Chiari malformation) in association with lumboperitoneal (LP) shunting is well recognized, it has previously been considered rare. In order to ascertain the incidence of this complication after LP shunting, the authors undertook a retrospective study of all patients in whom this form of shunt had been inserted between 1974 and 1991 at The Hospital for Sick Children, Toronto. In the 143 patients, the mean age at insertion was 3.3 years and the indications for shunt placement were hydrocephalus (81%), pseudotumor cerebri (7%), cerebrospinal fluid fistula (6%), and posterior fossa pseudomeningocele (6%). The mean follow-up period was 5.7 years, during which time there was one shunt-related death due to unsuspected tonsillar herniation. Five other patients developed symptomatic tonsillar herniation treated by suboccipital decompression.

Review of all computerized tomography (CT) scans not degraded by artifact showed evidence of excess soft tissue at the level of the foramen magnum in 38 (70%) of 54 patients so studied. In order to confirm that this CT finding represented hindbrain herniation, sagittal and axial magnetic resonance (MR) images were obtained for 17 asymptomatic patients and revealed tonsillar herniation (range 2 to 21 mm) in 12 (70.6%). In addition, some of these asymptomatic patients had evidence of uncal herniation and mesencephalic distortion. Similarities and distinctions are drawn between the morphological changes occurring after LP shunting and those seen in association with the Chiari I and II malformations. Although less than 5% of this study population required treatment for tonsillar herniation, the incidence of this complication was high in asymptomatic patients; MR imaging surveillance for patients with LP shunts is therefore recommended.
Subdural empyema: burr holes or craniotomy?
Authors: Bok Arnold P. L. , Peter Jonathan C.
Published: May 2009

✓ Ninety patients with subdural empyema were treated in the period after computerized tomography (CT) became available (1979 to 1991). Males predominated by a ratio of 2:1, and 40 patients were between 11 and 20 years old. The site of origin was the paranasal air sinuses in 53 patients, the middle ear in 19, and a superficial infection in eight; the source of infection was not known in 10. The most common clinical presentation was headache, fever, neck stiffness, seizures, or periorbital swelling; only seven patients had status epilepticus. While the erythrocyte sedimentation rate and white blood cell count were invariably elevated, the cerebrospinal fluid showed nonspecific pleocytosis in the 60 patients who underwent lumbar puncture. The definitive preoperative diagnosis was made by contrast-enhanced CT in all cases. Surgical treatment was by multiple burr holes in 37 patients, burr holes and small craniectomies in 33, burr holes with catheter drainage in seven, and a large craniotomy in 12. One patient was treated without surgery. The mortality rate was 7.7%, with 86% making a good recovery. These results compare favorably with those reported in other studies using craniotomy alone, and suggest that burr holes should not be disregarded as a method of treating subdural empyema where contrast-enhanced CT facilities are available.
Progressive myelopathy secondary to odontoid fractures: clinical, radiological, and surgical features
Authors: Crockard H. Alan , Heilman Alan E. , Stevens John M.
Published: May 2009

✓ Late-onset progressive myelopathy, years after odontoid fracture, is considered a rarity. Sixteen patients with diagnosis of their odontoid fractures delayed from four months to 45 years have been studied and treated. Three had forgotten about the injury and, in the rest, the significance had been minimized by their clinicians. Fifteen patients had characteristic C-2 nerve root pain and 10 had noted weak hands and walking difficulties. Fifteen patients had Type II fractures, which were mobile in 11; hypertrophic pseudarthrosis was marked in two. In seven patients it was confirmed at surgery that all or part of the transverse ligament was interposed in the fracture. Transoral surgery, combined with a variety of posterior fusion techniques, has allowed cord decompression, an understanding of the pathomechanics, and sound posterior bone fusion with arrest of the myelopathic condition.

Measurements of craniovertebral angles and cord cross-sectional area in this series revealed a rough correlation, but the most striking relationship was between length of delay in diagnosis and diminished cord area in both non-union and malunion, suggesting a progressive injury mechanism. It is proposed that late myelopathy following odontoid fracture may be more common than hitherto believed and should be considered in the evaluation of patients with cervical spondylosis. The condition may be progressive. Finally, non-union may be due to interposition of the transverse ligament.