bluuebunny/crossref_metadata_2025 huggingface dataset:
Intradural extramedullary spinal metastasis
Authors: Perrin Richard G. , Livingston Kenneth E. , Aarabi Bizhan
Published: May 2009

✓ The management of 10 patients with symptomatic localized intradural extramedullary spinal metastasis is reviewed. The single most common primary source was carcinoma of the breast (four cases). The initial symptom in nine patients was pain, with five patients reporting a characteristically severe cramping discomfort with radicular distribution. All patients underwent laminectomy decompression. At the time of surgery, six of the patients were weak but ambulatory and four were bedridden. Following surgery, four patients enjoyed some measure of pain relief, seven patients became ambulatory, and three remained bedridden. Two patients achieved a “satisfactory” result, and were walking and continent 6 months after surgery. Secondary brain tumors were demonstrated or implicated in nine patients, supporting the concept that the spinal metastases represented tertiary deposits following dissemination via the cerebrospinal fluid.

Symptomatic intradural extramedullary spinal metastasis causes a virulent clinical syndrome with poor prognosis and disappointing outcome after treatment. Given the high incidence of associated cerebral metastatic involvement, total neuraxis radiation and/or chemotherapy should be considered when symptomatic spinal metastasis is discovered to be intradural and extramedullary.
An unusual presentation of neurofibroma of the oculomotor nerve
Authors: Hiscott Paul , Symon Lindsay
Published: May 2009

✓ The authors describe a patient who presented with progressive dementia and hemiparesis. A neurofibroma was demonstrated arising from the intracavernous portion of the contralateral oculomotor nerve and the patient was treated successfully by subtotal excision.
Spontaneous subgaleal hematoma associated with a periosteal varix
Authors: Davidson Robin I. , Phillips Kathleen , Zito Joseph , Smith Thomas W.
Published: May 2009

✓ The spontaneous onset of an acute subgaleal hematoma in a 13-year-old boy is recorded. The underlying lesion causing the hemorrhage was believed to be an anomalous periosteal venous structure, which is briefly illustrated angiographically, grossly, and histologically.
Considerations in the diagnosis and treatment of syringomyelia and the Chiari malformation
Authors: Cahan Leslie D. , Bentson John R.
Published: May 2009

✓ A series of patients with abnormalities of the craniocervical junction with and without syringomyelia is reviewed. The impact of computerized tomography scanning on current radiological evaluation is discussed. Air myelography may no longer be necessary for accurate diagnosis. While the results of surgery for the Chiari malformation were good, at least one-half of the patients with syringomyelia showed continued progression of symptoms after posterior fossa surgery. More effective surgical therapy requires a better understanding of the pathogenesis of the syrinx.
Clinical recording of pressure on the spinal cord and cauda equina
Authors: Magnaes Bjørn
Published: May 2009

✓ When an intraspinal expanding lesion causes a spinal block, a segment of the spinal cord or cauda equina will be subjected to general pressure from the surrounding tissue. This spinal block pressure, the spinal equivalent to intracranial pressure, was measured by lumbar infusion of fluid and simultaneous recording of the volume-pressure curve caudal to the block. The point of deviation from or breakthrough of the exponential volume-pressure curve indicated the spinal block pressure. Spinal block pressure of about 500 mm H2O and more could be determined by this method, and, when it was combined with Queckenstedt's test, lower pressures could be assessed as well. In the static (thoracic) part of the spine, spinal block pressure up to the level of arterial blood pressure was recorded. In the dynamic part of the spine, however, spinal block pressure could exceed arterial blood pressure due to external compressive forces during extension of the spine.

There was a general tendency for more severe neurological deficits in patients with high spinal block pressure; but the duration of the pressure, additional focal pressure, and spinal cord compared with nerve root compression seemed equally important factors.

The recording has implications for diagnosis, positioning of patients for myelography and surgery, selection of high-risk patients for the most appropriate surgical procedure, and detection of postoperative hematoma. There were no complications associated with the recordings.
Clinical recording of pressure on the spinal cord and cauda equina
Authors: Magnaes Bjørn
Published: May 2009

✓ Pressure on the spinal cord with the neck in the extended position for endotracheal intubation was recorded in eight patients with a narrow spinal canal due to cervical spondylosis. Pressures up to about 1400 mm H2O were recorded. Longitudinal skeletal traction with the tong placed frontally reduced the pressure on the spinal cord in all patients. When longitudinal skeletal traction was applied, the stress of the neck extension was probably in part transferred from the lower cervical spine where the canal was narrow to the upper cervical spine with the more spacious canal. Placing the tong for longitudinal skeletal traction frontally when performing endotracheal intubation is advocated in patients with cervical spondylosis and probably also in patients with injuries of the lower cervical spine.
The activities of noradrenergic and dopaminergic neuron systems in experimental hydrocephalus
Authors: Miwa Soichi , Inagaki Chiyoko , Fujiwara Motokazu , Takaori Shuji
Published: May 2009

✓ Experimental hydrocephalus was induced in rabbits by intracisternal injection of kaolin suspension, and the concentration of noradrenaline (NA), dopamine (DA), and their metabolites was determined in several brain regions. The NA concentration had decreased in the cerebellum, hypothalamus, and pons plus medulla oblongata, and increased in the caudate nucleus at 2 days after kaolin injection (the stage of early intracranial hypertension). At 1 week (the stage of progressive hydrocephalus), the NA content had returned to control levels in all brain regions studied, and it decreased again at 4 weeks (the stage of chronic hydrocephalus) in the pons plus medulla oblongata. The DA level was unchanged throughout the 4-week period after kaolin injection.

The concentration of 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MOPEG-SO4), the major metabolite of NA, was elevated in all brain regions except the caudate nucleus at all stages after kaolin injection. An increase in MOPEG-SO4 in the caudate nucleus was also observed 1 week after kaolin injection. The content of homovanillic acid (HVA), the major metabolite of DA in the rabbit brain, was decreased in the cerebral cortex at 2 days and at 1 week after kaolin injection, and in the caudate nucleus at 2 days, 1 week, and 4 weeks. The level of HVA was increased in the hypothalamus at 2 days, in the cerebellum at 2 days and at 1 week, in the pons plus medulla oblongata at 2 days, 1 week, and 4 weeks, and in the midbrain at 4 weeks.

These data suggest that, in experimental hydrocephalus in the rabbit, NA release is increased throughout the brain, while DA release is decreased in the cerebral cortex and caudate nucleus, and increased in the cerebellum, hypothalamus, midbrain, and pons plus medulla oblongata.
Cerebellar infarction with obstructive hydrocephalus
Authors: Taneda Mamoru , Ozaki Koji , Wakayama Akatsuki , Yagi Keiichi , Kaneda Hirao , Irino Tadayoshi
Published: May 2009

✓ The authors review 15 patients with acute cerebellar infarction accompanied by obstructive hydrocephalus. These patients were among 1700 consecutive patients with acute cerebrovascular disease who were examined by angiography and also, except for the initial 320 cases, by computerized tomography (CT) scan. The CT scans were helpful in diagnosis and management of the patients. It demonstrated cerebellar mass lesions as being low density, isodense, or high density, according to the amount of hemorrhage into the infarcted area. Such cerebellar mass lesions caused acute compression of the posterior fossa. The clinical picture was determined mainly by the extent of the initially infarcted area in the vertebrobasilar territory and the speed of enlargement of the subsequently developing cerebellar mass lesion. Suboccipital decompressive surgery was performed in 10 patients and was generally beneficial. The postoperative prognosis depended mainly on the presence or absence of coexisting brain-stem infarction. Five patients who were managed conservatively died during the acute stage. Prompt and correct diagnosis of this illness is required to ensure adequate therapy.
A new radionuclide method for the diagnosis of posttraumatic cerebrospinal fistulas
Authors: Mamo Lysiane , Cophignon Jean , Rey Alain , Thurel Claude
Published: May 2009

✓ The authors describe their technique for identifying and localizing posttraumatic cerebrospinal fluid fistulas. The method entails injection of radionuclide tracer into the subarachnoid frontal space with the patient in a sitting position followed by gamma camera scintigraphic recordings. The results in 308 patients are presented; these are compared with those of suboccipital radionuclide cisternography in 40 cases and metrizamide computerized tomography cisternography in nine cases. Transient complications occurred in only three patients.
Spinal cord injury without radiographic abnormalities in children
Authors: Pang Dachling , Wilberger James E.
Published: May 2009

✓ Spinal cord injury in children often occurs without evidence of fracture or dislocation. The mechanisms of neural damage in this syndrome of spinal cord injury without radiographic abnormality (SCIWORA) include flexion, hyperextension, longitudinal distraction, and ischemia. Inherent elasticity of the vertebral column in infants and young children, among other age-related anatomical peculiarities, render the pediatric spine exceedingly vulnerable to deforming forces. The neurological lesions encountered in this syndrome include a high incidence of complete and severe partial cord lesions. Children younger than 8 years old sustain more serious neurological damage and suffer a larger number of upper cervical cord lesions than children aged over 8 years. Of the children with SCIWORA, 52% have delayed onset of paralysis up to 4 days after injury, and most of these children recall transient paresthesia, numbness, or subjective paralysis. Management includes tomography and flexion-extension films to rule out incipient instability, and immobilization with a cervical collar. Delayed dynamic films are essential to exclude late instability, which, if present, should be managed with Halo fixation or surgical fusion. The long-term prognosis in cases of SCIWORA is grim. Most children with complete and severe lesions do not recover; only those with initially mild neural injuries make satisfactory neurological recovery.
Paresthesias after lumbar disc removal and their relationship to epidural hematoma
Authors: Lauro Leonardo Di , Poli Roberto , Bortoluzzi Marco , Marini Giovanni
Published: May 2009

✓ The authors present two cases of epidural hematoma causing paresthesias and paresis after lumbar disc surgery. Good recovery followed removal of the hematomas.
Ganglion cyst of the spinal canal
Authors: Maresca Luigi , Meland N. Bradly , Maresca Carlotfa , Field E. Malcolm
Published: May 2009

✓ A case of spinal canal obstruction secondary to a ganglion cyst is reported. The clinical aspects and the pathological findings are described, and the pathogenetic theories related to the origin of ganglion cysts are reviewed. This case seems to support the origin of ganglion cysts of the spinal canal from the facet joints. A review has not disclosed any similar cases in the English literature.
Extrusion of a peritoneal catheter through the abdominal wall in an infant
Authors: Wakai Susumu
Published: May 2009

✓ A case is reported in which the Raimondi peritoneal catheter of a ventriculoperitoneal shunt spontaneously protruded from the abdominal wall of an 8-month-old infant.
Intraoperative use of real-time ultrasonography in neurosurgery
Authors: Chandler William F. , Knake James E. , McGillicuddy John E. , Lillehei Kevin O. , Silver Terry M.
Published: May 2009

✓ The authors' experience with the intraoperative use of real-time ultrasonography during 21 neurosurgical procedures is reported. These procedures include neoplasm surgery in 18 cases, treatment of an arteriovenous malformation in one case, and ventricular catheter placement for hydrocephalus in two cases. In each of the neoplasm cases, the tumors were imaged just as well through the intact dura as on the brain surface itself. There were no cases in which the pathology could not easily be identified. The use of portable intraoperative ultrasonography in sterile coverings has proven to be extremely useful in localizing small subcortical neoplasms, as well as locating the solid and cystic portions of deep lesions. It has assisted in guiding needles for both biopsy and aspiration. It has also accurately identified and guided Silastic catheters during their placement in the ventricular system in cases of hydrocephalus. The authors have found real-time ultrasonography to be an important new tool in the operating room and will continue to rely on its imaging ability during selected procedures in the future.
The effects of deep barbiturate coma on multimodality evoked potentials
Authors: Sutton Leslie N. , Frewen Tim , Marsh Roger , Jaggi Jurg , Bruce Derek A.
Published: May 2009

✓ The authors report their investigation of the effects of high-dose barbiturates on the multimodality evoked response in 9 cats. After baseline evoked responses were obtained, boluses of pentobarbital were infused intravenously at regular intervals, amounting to cumulative total doses of 9, 18, 27, 45, 63, 123, and 183 mg/kg at respective infusions. This resulted in gradually increasing serum pentobarbital levels, reaching therapeutic coma levels (4 to 5 mg/dl) after the fifth infusion. At this point, the electroencephalogram was flat, and pressor agents were required to maintain cardiovascular stability. Evoked responses were obtained 15 minutes after each infusion. Brain-stem auditory evoked response (BAER) showed little change in wave latencies at therapeutic coma levels of pentobarbital. Further barbiturates resulted in delay of the late components of this response. In the somatosensory evoked responses (SER), early brain-stem components were relatively unaffected by therapeutic coma levels. Late brain-stem components and the initial cortical response showed progressive latency increase. Late cortical (association cortex) waves were abolished at relatively low doses. The central conduction time was relatively unaffected. The late waves of the visual evoked responses (VER) were abolished with low-dose barbiturates (9 mg/kg). A single positive-negative complex persisted despite massive infusions. It is concluded that evoked responses may prove useful in monitoring patients in deep barbiturate coma, but barbiturate effects must be kept in mind.
The effects of gammahydroxybutyric acid on canine cerebral blood flow and metabolism
Authors: Baumann Kent W. , Kassell Neal F. , Olin Julie , Yamada Thoru
Published: May 2009

✓ Gammahydroxybutyric acid has been proposed as an alternative to high-dose barbiturate therapy for protecting the brain after ischemic or traumatic insult. The cerebral and systemic metabolic and vascular effects of gammahydroxybutyrate and its lactone analogue, gammabutyrolactone, are addressed in this paper. In anesthetized normal dogs, gammahydroxybutyrate or gammabutyrolactone was infused intravenously at a rate of 1 gm/kg/hr. Cerebral blood flow (CBF) decreased progressively with increasing doses of either agent. Cerebral metabolic rate of oxygen (CMRO2) increased initially with gammahydroxybutyrate, but not following gammabutyrolactone. Reduction in CBF exceeded that of CMRO2 at all doses in both series.

The primary systemic effect noted was a severe, lethal metabolic acidosis resulting from infusion of gammabutyrolactone. Gammahydroxybutyrate did not cause a similar acidosis. The imbalance of the CBF-CMRO2 reduction following gammahydroxybutyrate administration suggests that it has no advantage over barbiturates in the management of patients with cerebral vascular insufficiency or intracranial hypertension.
A model of focal cortical contusion in gerbils
Authors: Crockard Alan , Kang Joon , Ladds Graeme
Published: May 2009

✓ An experimental model of focal laceration and contusion in gerbils is described. Associated with this injury are systemic changes which are neurogenically mediated and result in an immediate reduction in blood pressure, bradycardia, and generalized reduction in cerebral blood flow. There is generalized edema, as judged by a decreased specific gravity in the brain, probably related to reduced blood flow; superimposed on this, there is an edema gradient which is maximal close to the injury. This, in turn, affects the local capillary bed and prevents any local increase in flow. A separate group studied over a longer time period (6 hours) did not reveal egress of Evans blue into the surrounding tissue and this is in contrast to reports from cold-injury studies.
Intravascular aggregation after acute intracranial hypertension by epidural balloon compression in cats
Authors: Fujimoto Shunichiro , Roccaforte Peter , Patel Ashok R. , Moody Robert A.
Published: May 2009

✓ The authors have studied the effect of acute intracranial hypertension produced by placement of an epidural balloon (control group) in cats, on cerebral perfusion, evoked responses, and hematological parameters. These elements were measured in similarly injured animals which underwent isovolemic hemodilution with dextran 75, after relief of intracranial hypertension. Four hours after balloon deflation, perfusion was markedly impaired in 30% of the control group, and was reduced to 11% in the dextraninfused group. The suppressed N1 amplitude of somatosensory evoked responses on the compression side, the reduced platelet aggregability, and the erythrocyte deformability by intracranial hypertension were all significantly more restored in the dextran-infused group after decompression. The percentage of platelets with volumes between 21.75 and 48.75 cu µ (normal 9.75 to 12.75 cu µ) significantly increased after decompression. Activation of platelets during intracranial hypertension leads to an increase in platelet volume from platelet aggregation, and correlates with a decrease in platelet aggregability. It was also suggested that reduction of erythrocyte deformability was not caused by erythrocyte aggregation.

The authors emphasize the role of intravascular factors such as vascular obstruction by platelet aggregates, and difficulty in passage of erythrocytes through capillaries due to reduced deformability, in the disturbance of the microcirculation following acute intracranial hypertension. The protective effect of dextran 75 by inhibition of platelets as well as hemodilution is stressed.
Acute subdural hematoma
Authors: Shenkin Henry A.
Published: May 2009

✓ In a consecutive series of 39 cases of acute subdural hematoma (SDH), encountered since computerized tomography diagnosis became available, 61.5% were found to be the result of bleeding from a small cortical artery, 25.6% were of venous origin, 7.7% resulted from cerebral contusions, and 5% were acute bleeds into chronic subdural hematomas. Craniotomy was performed promptly on admission, but there was no difference in survival (overall 51.3%) between patients with arterial and venous bleeds. The only apparent factor affecting survival in this series was the preoperative neurological status: 67% of patients who were decerebrate and had fixed pupils prior to operation died. Of patients with less severe neurological dysfunction, only 20% failed to survive.
Intramedullary cervical spinal cord abscess
Authors: Blacklock J. Bob , Hood Terry W. , Maxwell Robert E.
Published: May 2009

✓ A case of spontaneous intramedullary cervical spinal cord abscess is presented. The clinical and laboratory findings in cases of spinal cord abscess vary. Prompt diagnosis and drainage are stressed as critical factors in effectively managing the disease.
Angioma in the paraspinal muscles complicated by spinal epidural hematoma
Authors: Shima Fumio , Mihara Keiichi , Hachisuga Shoji
Published: May 2009

✓ This case of angioma in the paraspinal muscles with extension into the epidural tissue was complicated by epidural hematoma in the thoracolumbar region. The hemorrhage was caused by rupture of the part of the angioma lying in the epidural tissue. A spinal bruit was of great value in diagnosing the angioma. Percutaneous embolization of the feeding arteries of the angioma reduced bleeding during surgery and contributed to successful surgical treatment.
Structure and function: organization of a medical specialty for the rest of the 20th century
Authors: Clark W. Kemp
Published: May 2009

✓ The President of the American Association of Neurological Surgeons concentrates on the problems facing the specialty, the achievements of the past, and the mechanisms designed to foster the advancement and role of neurosurgery. To counter the difficult days ahead, he emphasizes the need for concerted effort and action on the part of neurosurgeons within the umbrella of the Association as spokesman for the specialty and advocate for the patients' welfare.
Minds and brains: angels, humans, and brutes
Authors: Adler Mortimer J.
Published: May 2009

✓ In his 1982 Cushing oration, a distinguished philosopher, author, and discerning critic presents a distillate of his phenomenally wide range of personal experience and his familiarity with the great books and teachers of the present and the past. He explores the differences and relationships between human beings, brute animals, and machines. Knowledge of the brain and nervous system contribute to the explanation of all aspects of animal behavior, intelligence, and mentality, but cannot completely explain human conceptual thought.
A simple hemostatic method using a metal shield for injury of a major cerebral artery
Authors: Yokoo Akira , Sugita Kenichiro , Kobayashi Shigeaki , Matsuo Koichi
Published: May 2009

✓ A new hemostatic method has been devised that uses a metal shield for treating accidentally injured major cerebral arteries. The metal shield is made of stainless steel, and has a small plate on its outer surface that allows it to be held in a regular aneurysm clip holder. Three different sizes of shield are available. The metal shield is applied to an injured artery with Oxycel and Biobond and held for a few minutes. Bleeding stops instantaneously. This is a simple and effective hemostatic method for an injured artery of small size. Experimental results and clinical application of this method are described.
Intraoperative monitoring of brain-stem auditory evoked potentials
Authors: Raudzens Peter A. , Shetter Andrew G.
Published: May 2009

✓ Intraoperative brain-stem auditory evoked potentials (BAEP's) were monitored in 46 patients undergoing intracranial surgery for a variety of pathological conditions to determine whether this technique was capable of providing useful information to the operating surgeon. Intraoperative BAEP's were unchanged throughout surgery in 34 patients (74%), and these individuals had no postoperative hearing deficits. Four patients (9%) developed an abrupt ipsilateral loss of all waveform components beyond Wave I and had postoperative evidence of a pronounced hearing loss in the affected ear. An additional patient demonstrated BAEP loss contralateral to the side of surgery, and this was associated with subsequent signs of severe brain-stem dysfunction. Seven patients (15%) developed intraoperative delays of BAEP waveform latency values, but maintained recognizable waveforms beyond Wave I. Postoperatively, their hearing was either normal or mildly impaired, and there were no indications of other brain-stem abnormalities. This group represents the individuals who may have been benefited by evoked potential monitoring, since corrective surgical measures were taken when latency delays were observed. Intraoperative BAEP's can be reliably and routinely recorded in an operating room environment. They provide a good predictor of postoperative auditory status, and may have prevented permanent neurological deficits in a small segment of patients by alerting the surgeon to potentially reversible abnormalities.
Multiple giant hydatid cysts of the brain
Authors: Sharma Ajay , Abraham Jacob
Published: May 2009

✓ A rare case of multiple primary hydatid cysts of the brain is reported in a 9-year-old girl. There were five cysts, occupying most of the right supratentorial region. The biggest cyst measured 9 cm across, while the smallest one was 4.5 cm in diameter. The diagnosis was based on computerized tomography findings. The patient did not have any evidence of hydatid disease elsewhere in the body. The delivery of all the cysts resulted in the dramatic neurological recovery of this patient.
Familial intracranial aneurysms
Authors: Fox John L.
Published: May 2009

✓ A case with two intracranial aneurysms is presented. The situation is unique because the patient was one of 13 siblings, seven of whom are now known to have harbored such aneurysms. The patient, now deceased from rupture of her aneurysm, was one of the two siblings who had previously refused elective angiography.
Spinal cord pathways mediating somatosensory evoked potentials
Authors: Powers Stephen K. , Bolger Catherine A. , Edwards Michael S. B.
Published: May 2009

✓ Using a CO2 laser, discrete thoracic spinal cord lesions were made in cats anesthetized with ketamine and xylazine (Rompun). Differences in cortical somatosensory evoked potentials (SEP's) produced with high-intensity stimulation (20 times the motor threshold) of each posterior tibial nerve were determined for nine different combinations of unilateral spinal cord lesions.

The results of these studies show that nerve fibers in the ipsilateral dorsal column, the ipsilateral dorsal spinocerebellar tract, and the contralateral ventrolateral tracts with respect to the side of leg stimulation, contribute to cortical SEP's. A lesion of the dorsal spinocerebellar tract affected only the early waves (< 30 msec) of the SEP from leg stimulation ipsilateral to the side of the lesion, whereas a solitary lesion of the ventrolateral tract caused changes primarily in the amplitude of later waves (> 30 msec) of the SEP produced by contralateral leg stimulation. Lesions involving one-half of the dorsal column caused changes in the amplitude of both the early and late waves produced by stimulation ipsilateral to the side of the lesion. The effects of various combinations of lesions on the cortical SEP's were not additive, which indicates significant interaction between afferent pathways.

These findings suggest that high-intensity peripheral nerve stimulation, which activates both C and A fibers, could be used intraoperatively to assess spinal cord function with more accuracy than the current practice of using a stimulus strength of twice the motor threshold. The importance of using anesthetic agents that do not depress cortical activity (which may affect the later components of the SEP) is also emphasized.
A comparative study of epidural and cisternal pressure in dogsM
Authors: Ivan Leslie P. , Choo Sin H.
Published: May 2009

✓ The epidural and cisternal pressure was recorded simultaneously in eight dogs. Epidural pressure was monitored with a Ladd fiberoptic sensor, and the cisternal pressure via a Statham transducer and a Grass polygraph. Various pressure levels were compared when mock cerebrospinal fluid was injected into the cisterna magna. The results were analyzed statistically and, within a range of 0 to 70 mm Hg, a high degree of correlation was found between the pressures of the two compartments (r = 0.96 to 1.0).
Thyrotrophin-producing pituitary adenomas
Authors: Hill Stephen A. , Falko James M. , Wilson Charles B. , Hunt William E.
Published: May 2009

✓ Hyperthyroidism due to thyrotrophin (TSH)-secreting pituitary tumors is rare. Four cases are described, with the features that allow preoperative diagnosis. In all the patients, thyroid hormone production was consistently elevated despite antithyroid therapy, and TSH levels were inappropriately elevated. All patients were treated with both surgery and irradiation. Each patient had recurrent tumor with suprasellar, intrasphenoidal, or intraorbital spread. The combination of a recurrent, aggressive tumor complicated by thyrotoxicosis makes this a complex and difficult surgical problem.
Compensatory growth following premature closure of the coronal suture in rabbits
Authors: Babler William J. , Persing John A. , Winn H. Richard , Jane John A. , Rodeheaver George T.
Published: May 2009

✓ Premature closure of a cranial suture results in skull deformation characterized by inhibited skull growth in a direction perpendicular to the course of the affected suture. Early surgical release of the closed suture results in a “normal” skull morphology. The present experimental study measured alterations in growth at the transverse cranial sutures that occurred following induced premature closure of the coronal suture and its subsequent release in New Zealand White rabbits. Using roentgenocephalometric methods, growth and morphometric changes were monitored at the frontonasal, coronal, and anterior lambdoid sutures following premature closure of the coronal suture at 9 days of age. The results indicated that premature closure of the coronal suture did not result in compensatory (increased) growth at the other transverse sutures of the vault. In fact, growth at these sutures was significantly reduced. This reduced growth at adjacent transverse sutures was not ameliorated by early surgical release of the fused suture.
Autoradiographic assessment of choroid plexus blood flow and glucose utilization in the unanesthetized rat
Authors: Tyson George , Kelly Paul , McCulloch James , Teasdale Graham
Published: May 2009

✓ Choroid plexus blood flow (CPBF) and glucose utilization (CPGU) were measured in two groups, each of seven identically prepared, unanesthetized rats, using complementary quantitative autoradiographic techniques. Both CPBF and CPGU were lowest in the lateral ventricles (0.83 ± 0.01 ml · g−1 · min−1 and 0.70 ± 0.02 µmoles · g−1 · min−1, respectively) and highest in the fourth ventricle (1.56 ± 0.05 ml · g−1 · min−1 and 1.39 ± 0.05 µmoles · g−1 · min−1, respectively). Despite this heterogeneity, the proportionate relationship between CPBF and CPGU was relatively constant throughout the ventricular system. This suggests that blood flow and metabolism may normally be coupled in the choroid plexus, and that the choroid plexus of the fourth ventricle may account for a disproportionate share of the functional activity of this tissue.
Increase in size of cerebral angiomas
Authors: Delitala Alberto , Delfini Roberto , Vagnozzi Roberto , Esposito Stefano
Published: May 2009

✓ A patient is reported in whom enlargement of a cerebral arteriovenous malformation (AVM) over 27 years was documented by angiography. The authors discuss the different theories about the growth of AVM's.
Extradural lipomatosis simulating an acute herniated nucleus pulposus
Authors: Archer Carol R. , Smith Kenneth R.
Published: May 2009

✓ A 48-year-old laborer presented with a 1-year history of low-back pain radiating into the posterior aspects of both thighs. Two weeks before admission, acute exacerbation resulted in signs and symptoms of compressive radiculopathy at L-5. Myelography revealed concentric constriction of the lower thecal sac due to abundant fat, as shown by computerized tomography. Laminectomy produced immediate relief of pain. The significance of these findings and a review of the literature are presented.
Schwannoma of the oculomotor nerves
Authors: Leunda Guillermo , Vaquero Jesus , Cabezudo Jose , Garcia-Uria Jose , Bravo Gonzalo
Published: May 2009

✓ The authors present a series of four schwannomas of the oculomotor nerves without evidence of von Recklinghausen's disease. The literature is reviewed and the clinical, radiological, and surgical aspects of these cases are discussed. The authors stress the usefulness of computerized tomography in the diagnosis and planning of treatment.
Giant aneurysm of the pericallosal artery
Authors: Pozzati Eugenio , Nuzzo Giacomo , Gaist Giulio
Published: May 2009

✓ A case is reported of a thrombosed giant aneurysm of the pericallosal artery. Neurological presentation was attributable to the acute swelling of the aneurysmal mass after rapid and massive intraluminal thrombosis. This case demonstrates that initial symptoms in giant aneurysms may be related to the thrombotic events within the enlarged sac. The computerized tomography characteristics of this case are reported and discussed.
A flow-regulating device to control differential pressure in CSF shunt systems
Authors: Yamada Hiroshi
Published: May 2009

✓ A method of regulating flow rate through cerebrospinal fluid (CSF) shunts with the addition of a flow-regulating device (FRD) is reported. The FRD consists of a small-caliber (0.4 mm) Teflon tube placed in the usual connector. This device has the advantage of converting the original shunt valves to valves for higher-resistance flow without replacing the entire distal catheter. An experimental study revealed that this device reduced the CSF flow rate in the shunt system by approximately 30%. The author has found it reliable in 32 patients, without causing CSF obstruction. The device is easily installed and removed.
Spinal cord injury, spinal fracture, and spinal stenosis in ankylosing spondylitis
Authors: Weinstein Philip R. , Karpman Robert R. , Gall Eric P. , Pitt Michael
Published: May 2009

✓ The authors report a retrospective review of 105 patients with ankylosing spondylitis (AS) diagnosed over a 6-year period in Tucson, Arizona. In the series, there were 13 patients with spinal fracture and eight with severe spinal cord injury. Two patients with central cord contusion had no demonstrable cervical spine fracture. Injury was often trivial and dislocation at fracture sites was minimal, demonstrating the extreme fragility of these patients. Spinal stenosis, which has not previously been associated with AS, was documented in three cases. Pseudarthrosis, a destructive vertebral lesion that does not require surgical decompression or fusion, was found in four patients; this entity is believed to originate as a pathological or traumatic fracture. Atlanto-axial subluxation and basilar invagination associated with spinal ankylosis occurred in one patient. The study emphasizes the value of computerized tomography scanning of the spine for diagnosis, and halo-vest application as a nonoperative treatment for cervical immobilization. Early diagnosis and appropriate therapy to decompress, reduce, and immobilize unstable spinal lesions may result in reduction of the 29% mortality rate and 46% permanent neurological morbidity rate observed after spinal fracture in this series of AS patients. Because of the high operative complication rate observed, nonsurgical immobilization is the recommended treatment unless spinal dislocation or bone fragment displacement has occurred at the fracture site.
Secondary removal of retained bone fragments in missile wounds of the brain
Authors: Meirowsky Arnold M.
Published: May 2009

✓ Secondary operations for the removal of retained bone fragments have been performed in 116 of the 1133 casualties with craniocerebral missile wounds incurred in the war in Vietnam, 1967 to 1970. Various complications developed in 19 of these 116 casualties. Dehiscence of the wound occurred in eight patients, five of whom developed a cerebrospinal fluid fistula. Infection manifested itself in 16 cases with retained bone fragments prior to their secondary removal; however, infection first became apparent after the secondary operation in seven patients. Two of the seven patients with infection died. The neurological deficit became worse in four of the 116 patients following the secondary removal of a bone fragment: there was complete resolution of that deficit in one, and return to the neurological status existing after the initial operation in another; the other two patients developed a permanently disabling neurological deficit, an incidence of 1.7%.
Effect of early operation for ruptured aneurysms on prevention of delayed ischemic symptoms
Authors: Taneda Mamoru
Published: May 2009

✓ The effect of removal of subarachnoid blood clots on the prevention of delayed ischemic deficit was evaluated in 239 consecutive patients with ruptured supratentorial non-giant aneurysms. All patients were hospitalized within 24 hours after subarachnoid hemorrhage (SAH) and were classified in Grades 1 to 4 according to the system of Hunt and Hess; classification was made immediately preoperatively in patients operated on within 48 hours after SAH, or 48 hours after SAH in patients for whom delayed operation was planned. Delayed ischemic deficit causing permanent disability or death occurred in 11 (25%) of 44 patients in whom surgery was planned to be delayed for 10 days or more, in 26 (27.7%) of 94 patients in whom the aneurysms were obliterated and blood clots adjacent to them were removed within 48 hours of SAH, and in 11 (10.9%) of 101 patients in whom the aneurysms were obliterated and extensive and aggressive removal of thick subarachnoid clots lying along the arteries (identified on computerized tomographic scan) was performed within 48 hours of SAH. Accordingly, early operation is an effective and reliable method to reduce the occurrence of severe delayed ischemic deficit only when subarachnoid blood clots are removed extensively and aggressively along the arteries within 48 hours of SAH.
Valve invagination in ventriculoatrial shunting
Authors: Hassler Werner , Gilsbach Joachim , Harders Albrecht , Hemmer Robert
Published: May 2009

✓ The authors present eight cases of an unusual mechanical complication of ventriculoatrial shunts that has not been reported previously. In these eight patients, the metal parts of the valve slipped into the silicone casing. Although the cause is not completely clear, there are simple ways of preventing this from happening.
Use of cavernous sinography to detect aneurysms or anomalies of the infraclinoid carotid artery
Authors: Teasdale Graham , Macpherson Peter
Published: May 2009

✓ Four cases are described to illustrate the ability of cavernous sinography to detect coincidental aneurysms or anomalies of the infraclinoid carotid artery. Sinography may be used as a preliminary step before a transsphenoidal operation, in order to identify the small proportion of cases in which arteriography should be performed.
Performance of chronically implanted induction-powered oscillator epidural pressure transducers
Authors: Rylander H. Grady , Story Jim L. , Taylor H. Lyndon
Published: May 2009

✓ Chronic measurements of epidural pressure made with an induction-powered oscillator transducer revealed several problems with the current design of the device. All transducers failed over a period of months due to the diffusion of extracellular fluid through epoxy seals, which resulted in corrosion of the electrical components. Significant fibrosis occurred around the circumference of the burr hole, which reduced the sensitivity of the transducers. Design modifications are suggested to circumvent these problems.
Implanted pulsatile balloon device for simulation of neurovascular compression syndromes in animals
Authors: Segal Ricardo , Jannetta Peter J. , Wolfson Sidney K. , Dujovny Manuel , Cook Eugene E.
Published: May 2009

✓ A self-contained neurovascular compression simulator (NCS) has been designed to function as an artificial artery that pulsates with the heart. When implanted in animals, this device simulates those naturally occurring situations in which there is compression of nervous elements in the region of the brain stem or other areas by aberrant, or ectatic branches of normal arteries. The NCS consists of an intra-aortic balloon, a smaller (cephalic) balloon, a connecting tube, and an injection port, all fabricated of polyurethane-silicone compounds. With each heart systole, the rise in intra-aortic pressure is transmitted to the smaller cephalic balloon in the form of a pulsation. Thus, part of the cardiac ejection energy is transferred to the desired nervous structures. The performance of each NCS is tested in vitro in a pulse duplicator system.

The NCS was chronically implanted for up to 2 years in four dogs and 10 baboons. The cephalic balloon was placed intracranially in the subarachnoid space on the ventrolateral medulla adjacent to the entry zone of the ninth and 10th cranial nerves on the left side of baboons and on the right side of dogs. The position of the balloons was checked by fluoroscopy. Following implantation, the NCS could be inflated or deflated at will using the injection port which served to restart or discontinue the pulsations. No occlusion of the aorta or reduction of blood flow to the lower limbs or trunk was detected. By means of the NCS, an experimental model of neurogenic hypertension was produced in baboons.
Ultrastructural changes in rat peripheral nerve following pneumatic tourniquet compression
Authors: Nitz Arthur J. , Matulionis Daniel H.
Published: May 2009

✓ The sciatic nerves of 12 male rats were examined in the electron microscope 14 days after pneumatic tourniquet compression. Tourniquet pressure was maintained at 300 mmHg for varied lengths of time (30 minutes to 3 hours). Nerves compressed for 30 minutes showed very mild fissuring of the myelin without axonal degeneration. Examination of nerves compressed for 1 to 3 hours showed progressively more varied and extensive damage. Changes included splaying of myelin lamellae, axonal shrinkage with periaxonal edema, Schwann cell hypertrophy, and an increase in the number of microtubules and mitochondria per unit area. The myelin sheaths of some fibers, compressed for more than 2 hours, were completely ruptured. These changes resemble nerve lesions which could be induced by a variety of experimental procedures. Ultrastructural changes produced by tourniquet compression are apparently time-related and affect large-diameter nerves more profoundly than smaller-diameter nerves.

The data reported provide an explanation for delayed muscle rehabilitation experienced by patients who have undergone extremity surgery with pneumatic tourniquet application. The evidence presented suggests that the incidence of tourniquet palsy may be far greater than previously recognized.
Effect of high-dose corticosteroid therapy on blood flow, evoked potentials, and extracellular calcium in experimental spinal injury
Authors: Young Wise , Flamm Eugene S.
Published: May 2009

✓ High-dose methylprednisolone (15 to 30 mg/kg), administered 45 minutes after severe contusion injury (400 gm-cm) to cat spinal cords, rapidly reverses the typical posttraumatic ischemia that occurs in spinal injuries. White matter blood flow improves despite the systemic hypotension associated with bolus intravenous injections of such massive corticosteroid doses. In addition, this treatment facilitates extracellular calcium ionic recovery in contused spinal cords, and salvages evoked potential activity that is lost in untreated cats. These data suggest that high-dose corticosteroid treatment causes local vasodilation of spinal cord blood vessels. The consequent blood flow increase may account for the beneficial effects of high-dose corticosteroid treatment on both functional recovery and histopathological appearance of injured spinal cords.
Intraoperative monitoring of brain-stem auditory evoked potentials
Authors: Grundy Betty L. , Jannetta Peter J. , Procopio Phyllis T. , Lina Agnes , Boston J. Robert , Doyle Earl
Published: May 2009

✓ Brain-stem auditory evoked potentials (BAEP) were monitored during 54 neurosurgical operations in the cerebellopontine angle. The BAEP were irreversibly obliterated in five patients who required deliberate section of the auditory nerve. Technical difficulties interfered with monitoring in three cases, and three patients had deafness and absent BAEP preoperatively.

Reversible alterations in BAEP were seen during 32 operations, with recovery after as long as 177 minutes of virtually complete obliteration. Changes in BAEP were associated with surgical retraction, operative manipulation, positioning of the head and neck for retromastoid craniectomy, and the combination of hypocarbia and moderate hypotension. In 19 cases, waveforms improved after specific interventions made by the surgeon or anesthesiologist because of deteriorating BAEP. In 13 other cases, BAEP recovered after maneuvers not specifically related to the electrophysiological monitoring, most often completion of operative manipulation. Whenever BAEP returned toward normal by the end of anesthesia, even after transient obliteration, hearing was preserved. Irreversible loss of BAEP occurred only when the auditory nerve was deliberately sacrificed. The authors conclude that monitoring of BAEP may help prevent injury to the auditory nerve and brain stem during operations in the cerebellopontine angle.
Surgical treatment of spinal cord astrocytomas of childhood
Authors: Epstein Fred , Epstein Nancy
Published: May 2009

✓ This report describes the first author's surgical experience with a series of 19 consecutive cases of spinal cord astrocytoma treated over the past 2 years, with a follow-up period of 6 to 24 months. The clinical presentation, neurodiagnostic investigation, surgical technique, and results are analyzed. The authors conclude that radical resection (gross total removal of the tumor) is the optimal therapeutic option.
Spinal intradural schwannoma without attachment to a nerve root
Authors: Bollati Angelo , Galli Giuseppe , Gandolfini Massimo , Marini Giovanni , Pizzoli Gabriele
Published: May 2009

✓ The authors report an unusual case of intradural schwannoma, without demonstrable nerve root connection. An original explanation is given.
Surgical treatment of post-lumbar puncture dural CSF leak causing chronic headache
Authors: Harrington Hugh , Tyler H. Richard , Welch Keasley
Published: May 2009

✓ A-58-year-old woman experienced incapacitating headache and occipital paresthesiae for 5 years after lumbar myelography. Conservative methods of treatment failed. Successive investigations for a suspected cerebrospinal fluid (CSF) leak were unrevealing. Leakage of CSF from the subarachnoid space into the epidural space in the lumbar region was finally confirmed when oil-soluble contrast material (Pantopaque), injected into the cervical subarachnoid space, was revealed by a specific technical modification to be escaping from the lumbar sac. Repair of the dural defect with dorsolumbar fascia resulted in almost complete alleviation of symptoms. This case is unusual because of the radiographic technique used, the duration of symptoms, and the rarity of reports of successful surgical treatment for this serious complication of lumbar puncture.
Air embolism associated with wounds from a pin-type head-holder
Authors: Pang Dachling
Published: May 2009

✓ A case of intraoperative air embolism during posterior fossa surgery performed with the patient in the sitting position is reported. The entry site was through a comminuted fracture and scalp laceration resulting from faulty application of a pin-type head-holder. The possible role played by a large tension pneumocephalus in the ingress of venous air is also discussed. Simple precautions regarding the use of the pin-type head-holder are suggested to lessen the possibility of air embolism through the puncture wounds.