bluuebunny/crossref_metadata_2025 huggingface dataset:
Normal computerized tomography scans in severe head injury
Authors: Lobato Ramiro D. , Sarabia Rosario , Rivas Juan J. , Cordobes Francisco , Castro Servando , Muñoz Maria J. , Cabrera Antonio , Barcena Alejandro , Lamas Eduardo
Published: May 2009

✓ The authors analyze the clinical course of 46 severely head-injured patients who had completely normal computerized tomography (CT) scans through the immediate posttraumatic period (1 to 7 days after trauma). These patients represent 10.2% of a consecutive series of 448 cases of severe head injuries and two-thirds of the cases showing a normal CT scan on admission (the other one-third of the cases developed new pathology). The usual course in these 46 patients after the initial coma was toward progressive neurological improvement, and 35 patients (76%) achieved a functional level of survival. Nine patients (19.5%) remained comatose for several weeks and developed severe disability. There were two fatalities due to medical complications. The final outcome was more closely related to the duration of coma (the longer the duration the worse the result) than to the initial Glasgow Coma Scale (GCS) score. In fact, 26% of the patients in the lower GCS score ranges (3 to 4 points) made a good recovery and 46% developed moderate disability only. These findings indicate that the grim prognostic significance of deep posttraumatic coma is tempered in the presence of a normal scan. However, the absence of CT abnormalities in severely head-injured patients cannot be equated with a good prognosis because in one-fifth of the cases serious permanent disability develops.

Sustained elevation of the intracranial pressure (ICP) was not seen in these patients, indicating that ICP monitoring may be omitted in cases with a normal scan. However, since one-third of the patients with a normal admission scan developed new pathology within the first few days of injury, a strategy for control scanning is recommended. Control CT scans performed more than 6 months after injury showed a significantly higher incidence of brain atrophy in patients developing permanent disability than in those who made a good recovery.
Inhibition of dorsal-horn cell responses by stimulation of the Kölliker-Fuse nucleus
Authors: Hodge Charles J. , Apkarian A. Vania , Stevens Richard T.
Published: May 2009

✓ The Kölliker-Fuse nucleus (KF) in the dorsolateral pons has been shown to be the major source of catecholamine innervation of the spinal cord. This has important implications in terms of pain control mechanisms, since catecholamine-mediated mechanisms are essential for the expression of opiate and other varieties of antinociception. This study examines the effects of KF stimulation on responses of dorsal-horn cells to innocuous and noxious cutaneous stimuli in anesthetized cats. Stimulation of the KF potently inhibits the responses of dorsal-horn cells to both noxious and innocuous stimuli. The threshold for the inhibitory effect is significantly lower for responses to noxious stimuli as opposed to innocuous stimuli. The inhibitory effect is specific to the stimulus site, as evidenced by a marked decrease in the effect following small changes in the position of the stimulating electrode in the brain stem. The latency of the effects indicates a bulbospinal conduction velocity of 4 to 5 m/sec, which is much slower than usual reticulospinal effects and is consistent with a catecholamine-mediated system. The dependence of KF-spinal inhibition on intact biogenic amines was tested by depleting the animals of these amines with reserpine pretreatment. Depletion of biogenic amines resulted in a significant decrease in the KF spinal inhibitory effects, suggesting their dependence on intact noradrenergic stores. The results of these studies are consistent with the idea that the KF-spinal system plays an important noradrenergic-dependent role in the brain-stem modulation of spinal processing of noxious, potentially painful stimuli.
Beagle puppy model of perinatal cerebral insults
Authors: Ment Laura R. , Stewart William B. , Duncan Charles C. , Pitt Bruce R.
Published: May 2009

✓ Asphyxia, with its attendant hypoxemia, is by far the most common cause of neonatal cerebral infarction, and frequently results in lesions of the parieto-occipital white matter in addition to other neuropathological changes. This study examines the effects of hypoxemia on regional cerebral blood flow (CBF) in the newborn beagle pup. The animals were anesthetized, underwent a tracheotomy, and were paralyzed. Pups were randomly divided into two groups: one group was subjected to hypoxemia produced by altering the oxygen concentration in the inspired air, and the other received no insult. In the hypoxemic pups, the pO2 was 13.1 ± 2.1 mm Hg (mean ± standard deviation). Autoradiographic determinations of CBF were performed by the carbon-14-iodoantipyrine technique 15 minutes after randomization. Significant increases in CBF were found throughout the brains of the hypoxemic pups. The CBF was increased to cortical and central gray regions and to frontal and temporal white matter but was unchanged in the parietal white matter, one of the classic sites of radiological and neuropathological injury in neonates with perinatal asphyxia. An unexpected finding was the increased incidence of germinal matrix and/or intraventricular hemorrhages in the hypoxemic pups.
Cylindromas of the base of the skull
Authors: Vincentelli François , Grisoli François , Leclercq Toussaint A. , Ardaud Bernard , Diaz-Vasquez Pedro , Hassoun Jacques
Published: May 2009

✓ Cylindromas are rarely encountered in the neurosurgical field. Four cases of this rare tumor are presented. Conventional and computerized tomography scanning were most useful in establishing the diagnosis; angiography did not provide any further information. Because these tumors are well demarcated from surrounding structures, even in cases of recurrence, surgery is the treatment of choice. Radiation therapy is useful in the postoperative management. Long survival times with multiple recurrences are the rule.
Traumatic atlanto-occipital dislocation
Authors: Traynelis Vincent C. , Marano Gary D. , Dunker Ralph O. , Kaufman Howard H.
Published: May 2009

✓ Traumatic atlanto-occipital dislocation is a serious injury that is usually fatal. The number of patients surviving this injury, however, appears to be increasing, and most of these survivors are children. This may reflect an improvement in emergency transport services. Seventeen previously reported cases of patients surviving atlanto-occipital dislocation for more than 48 hours are reviewed and an additional case is presented. Many of these patients had an excellent neurological outcome. The radiographic criteria necessary for the diagnosis of atlanto-occipital dislocation are discussed. Cervical computerized tomography may confirm the diagnosis when necessary. It is suggested that there are three types of atlanto-occipital dislocation; utilizing this new classification, a rationale for treatment is described. Fusion is favored for long-term stability.
Sequential CT study of subependymal giant-cell astrocytoma associated with tuberous sclerosis
Authors: Morimoto Kazuyoshi , Mogami Heitaro
Published: May 2009

✓ The authors describe the growth pattern of a subependymal giant-cell astrocytoma associated with tuberous sclerosis, which was documented by sequential computerized tomography scans over 7 years. The diagnosis and treatment of this tumor are discussed, and the pertinent literature is reviewed.
Natural history of postoperative aneurysm rests
Authors: Feuerberg Isaac , Lindquist Christer , Lindqvist Melker , Steiner Ladislau
Published: May 2009

✓ In a series of 715 patients operated on by microsurgical techniques for intracranial saccular aneurysms between 1970 and 1980, part of the aneurysmal sac was not obliterated in 28 aneurysms in 27 patients (3.8% of 715 cases). Clinical follow-up evaluation for 8 years (range 4 to 13 years) and angiographic follow-up studies for 6 years (range 2 to 10 years) in these 27 cases revealed that one aneurysm rest increased in size and bled twice, five were spontaneously obliterated, two decreased in size, 13 remained unchanged, and in seven cases no late follow-up angiography was performed. The incidence of rebleeding from an aneurysm rest was 3.7% of the 27 in whom the sac was not obliterated and 0.14% of all 715 patients who were operated on.
Primary spinal melanoma
Authors: Larson Theodore C. , Houser O. Wayne , Onofrio Burton M. , Piepgras David G.
Published: May 2009

✓ The records of five patients with primary melanoma of the spinal cord were reviewed. The tumor most frequently presented as an intramedullary middle or lower thoracic cord lesion. The average duration of symptoms before pathological diagnosis was 29 months, and the average survival after laminectomy and radiation therapy was 6 years 7 months. The findings in this series, when compared with those in the literature, suggest that primary spinal melanoma is a more indolent malignancy than previously reported or than melanoma metastatic to the central nervous system.
Meningeal melanocytoma
Authors: Winston Ken R. , Sotrel Ana , Schnitt Stuart J.
Published: May 2009

✓ A melanin-producing, encapsulated, histologically benign-appearing tumor of the trigeminal nerve was surgically removed from a 9-year-old boy. It recurred 6 months later and was then subtotally resected and treated with radiation therapy. The clinical and pathological features of this and 10 similar cases reported in the literature are reviewed. These tumors are best categorized as meningeal melanocytomas.
Desmoplastic supratentorial neuroepithelial tumors of infancy with divergent differentiation potential (“desmoplastic infantile gangliogliomas”)
Authors: VandenBerg Scott R. , May Estelle E. , Rubinstein Lucien J. , Herman Mary M. , Perentes E. , Vinores S. A. , Collins V. Peter , Park T. S.
Published: May 2009

✓ Eleven cases of supratentorial neuroepithelial tumor presenting in infancy are reported. The tumors were characterized by their voluminous size, their intense desmoplasia, and the frequent presence of divergent astrocytic and ganglionic differentiation as demonstrated by special neurohistological and immunohisto- and immunocytochemical techniques. All the tumors presented in subjects below the age of 18 months, usually within the first 4 months of life. They most often involved the frontal and parietal regions and were composed predominantly of a dense desmoplastic tissue superficially resembling a moderately cellular fibroma. The fibroblastic elements were admixed with variable numbers of pleomorphic neuroepithelial cells. Divergent astrocytic and neuronal differentiation was demonstrable in nine of the 11 tumors. All showed astrocytic differentiation. The study of one example by electron microscopy, immunocytochemistry, and tissue culture disclosed that the astrocytic tumor cells were partly invested by a pericytoplasmic basal lamina. Successful total or near-total surgical resection has been followed by a favorable postoperative course extending in some cases over many years of tumor-free survival. The name “desmoplastic infantile ganglioglioma” is proposed for this apparently distinct clinicopathological entity, whose massive size is indicative of a pre- or perinatal origin. Its identification can be achieved by careful histological analysis and is of obvious prognostic significance.
Intravenous digital subtraction angiography and duplex ultrasonography in postoperative assessment of carotid endarterectomy
Authors: Pelz David , Rankin Richard N. , Ferguson Gary G.
Published: May 2009

✓ Seventy-four consecutive patients who had undergone carotid endarterectomy procedures were examined with intravenous digital subtraction angiography (IV-DSA) and duplex ultrasonography (DUS) at intervals ranging from 1 to 14 months postoperatively. Ninety-one percent of the DUS and 74% of the DSA images were of diagnostic quality. The two modalities agreed in the assessment of the endarterectomy appearance in 84% of the arteries, with 85% showing no evidence of significant residual disease. There were no arteries with severe restenosis or complete occlusion. In the 10 vessels in which the two modalities disagreed in disease assessment, the IV-DSA images were often degraded by artifact or vessel overlap leading to underestimation of disease. The authors conclude that DUS is the examination of choice for routine follow-up studies of carotid endarterectomy.
Craniotomy flap osteomyelitis: a diagnostic approach
Authors: Blumenkopf Bennett , Hartshorne Michael F. , Bauman John M. , Cawthon Michael A. , Patton James A. , Friedman Allan H.
Published: May 2009

✓ Nine cases of suspected craniotomy flap osteomyelitis evaluated by combined bone and gallium scanning are presented. In six cases, the clinical data were inconclusive and evaluation by radionuclide imaging provided an accurate negative diagnosis. The other three cases considered positive by this technique were proven infected at subsequent exploration and flap removal. The use of radionuclide bone and gallium imaging should be considered in cases of possible craniotomy flap osteomyelitis.
Extensibility of the lumbar and sacral cord
Authors: Tani Satoshi , Yamada Shokei , Knighton Robert S.
Published: May 2009

✓ Tethered spinal cord, or tethered cord syndrome, describes a disorder manifested by progressive motor and sensory deficit in the legs and by incontinence. Tethered cord syndrome occurs when the elongated spinal cord is anchored by a thick filum terminale or other pathological structures. The underlying mechanism is impairment of oxidative metabolism in the lumbosacral cord. The authors studied the extensibility of various parts of lumbar, sacral, and coccygeal segments in experimental animals and correlated this with the oxidative metabolism in these segments.

The filum terminale possesses far greater extensibility than any spinal cord segments and functions as a buffer in preventing the cord from overstretching. The lumbar, sacral, and coccygeal segments elongate under traction only below the attachment of the lowest pair of dentate ligaments. The lower the cord segment, the greater the percentage of elongation in spite of limited elasticity of the cord tissue; this greater percentage of elongation of the spinal cord correlates with increasing impairment of the oxidative metabolism and more severe neurological deficit. These findings explain such symptoms and signs as motor and sensory deficits in the legs associated with the human tethered cord syndrome, and correspond with the high clinical incidence of incontinence.

The lower spinal cord segments elongated promptly within 3 seconds after the start of traction. This implies that repeated acute hyperextension and hyperflexion, as occurs in humans, may accentuate oxidative metabolic changes that have already been caused by chronic cord tethering. The authors conclude that the elongation of the spinal cord under traction parallels the degree of metabolic dysfunction.
Intravascular balloon embolization of a large mid-basilar artery aneurysm
Authors: Hieshima Grant B. , Higashida Randall T. , Wapenski Joseph , Halbach Van V. , Bentson John R.
Published: May 2009

✓ A patient who presented with multiple episodes of subarachnoid hemorrhage was diagnosed as having a large mid-basilar artery aneurysm that had no definable surgical neck. Balloon embolization was performed utilizing two detachable silicone balloons to occlude the mid-basilar artery and the aneurysm. The procedure was carried out with the patient fully awake and alert. One day after the procedure, the patient developed pontine and cerebellar ischemia which completely resolved after 5 days on heparin therapy. A follow-up angiogram performed immediately after the procedure and at 3 months demonstrated complete occlusion of the mid-basilar artery and the aneurysm. The patient was intact neurologically upon discharge 5 days after the embolization procedure and has since resumed his normal activities. Balloon embolization therapy may offer some advantages over surgical methods for the treatment of such therapeutically challenging aneurysms.
Chondroma of the cervical spine
Authors: Lozes Gérald , Fawaz Ahmad , Perper Harry , Devos Philippe , Benoit Pascal , Krivosic Ian , Jomin Michael
Published: May 2009

✓ The authors report a case of cervical chondroma presenting with a syndrome of spinal cord compression in a 76-year-old woman. Total surgical removal of the lesion was followed by partial neurological recovery. Chondromas of the vertebral column are rarely reported in the literature.
Elusive tumor of the cauda equina
Authors: Tavy Denés L. J. , Kuiters Rudolf R. F. , Koster Pieter A. , Hekster Ruben E. M.
Published: May 2009

✓ A patient with a mobile schwannoma of the cauda equina is described. There was considerable discrepancy between the localization of the tumor at myelography and the findings at both initial surgery and repeat myelography, confirmed by definitive surgery. Such mobility is rare, but should be kept in mind when surgery is performed for a tumor of the cauda equina.
Cavernous angioma of the cauda equina producing subarachnoid hemorrhage
Authors: Ueda Shinsuke , Saito Akihito , Inomori Shigeo , Kim Ilu
Published: May 2009

✓ A case of a cavernous angioma of the cauda equina is presented. The patient was a 28-year-old man who experienced sudden low-back pain and headache without neurological symptoms. Lumbar puncture revealed subarachnoid hemorrhage. He had suffered a similar episode 3 years previously. Selective spinal angiography did not demonstrate any abnormal vascularity. Metrizamide myelography and magnetic resonance imaging were useful in demonstrating the presence of a tumor. Laminectomy at L1–3 and total removal of the tumor were performed without neurological deficit.
Percutaneous automated discectomy: a new method for lumbar disc removal
Authors: Maroon Joseph C. , Onik Gary
Published: May 2009

✓ A new technique for percutaneous lumbar disc removal is described. The specially designed 2-mm blunt-tipped suction/cutting probe (nucleotome) is similar to the automated vitrectomy instrumentation used by ophthalmic surgeons. The procedure is performed under local anesthesia, with the patient in the prone position and with fluoroscopic guidance. The nucleotome is inserted into the appropriate disc space with specially designed instrumentation, guided by landmarks similar to those used in needle placement for chemonucleolysis.

The technique has been evaluated in 20 patients with herniated discs (one at the L3-4 level and 19 at the L4-5 level) confirmed by myelography and/or computerized tomography scans after all conservative therapy for primarily radicular pain had failed. From 1 to 7 gm of disc material was removed in an average total operative time of approximately 1 hour. Eighty percent of the patients had good to excellent results in a short-term follow-up period of 6 months. Four patients subsequently required standard surgical excision of free disc fragments. No significant complications occurred. The procedure is contraindicated in patients with extruded or free fragments of disc in the spinal canal or in patients with herniations at the L5-S1 level pending development of additional instrumentation for insertion at that level. More extensive long-term studies are needed to further evaluate this procedure.
Long-term intrathecal baclofen infusion for treatment of spasticity
Authors: Penn Richard D. , Kroin Jeffrey S.
Published: May 2009

✓ Seven patients with spasticity of spinal cord origin have been maintained for up to 2 years with continuous spinal intrathecal infusion of baclofen. Prior to treatment, all of the patients had severe rigidity in their lower limbs and most had frequent and extensive spontaneous spasms, all of which greatly interfered with their activities of daily living. Oral antispasmodic medications were ineffective or caused central side effects. The patients underwent implantation of a programmable drug pump connected to a lumbar subarachnoid catheter. Within days of beginning continuous intrathecal baclofen infusion, the muscle tone was reduced to normal levels and spasms were eliminated. Over the ensuing months, muscle tone remained normal, but short-duration spasms could be induced by some activities. The greatest benefits to the patients were improvement in activities of daily living and better sleep due to reduced spasms. The baclofen doses were increased over the first few months but then were stabilized or only increased slightly, with the maximum dose being 650 μg/day. The most serious complications were two drug overdoses which took several days to clear up and were due to malfunctions of an earlier pump model. Baclofen clearance from the cerebrospinal fluid occurs with a half-life of 5 hours. The most serious concern in maintaining patients indefinitely on intrathecal baclofen is whether drug tolerance will eventually occur.
Surgical treatment of Cushing's disease
Authors: Chandler William F. , Schteingart David E. , Lloyd Ricardo V. , McKeever Paul E. , Ibarra-Perez Gloria
Published: May 2009

✓ The endocrinological, radiological, surgical, and pathological experience with 34 consecutive patients operated on for Cushing's disease is presented. Preoperative endocrine evaluation demonstrated that 19 patients had “typical” endocrine patterns for pituitary adrenocorticotropic hormone (ACTH)-dependent hypercortisolism and 11 had “atypical” testing. Pituitary pathology was found in 95% of the patients with typical preoperative endocrine testing but in only 55% of those with atypical testing. Eight of 34 preoperative computerized tomography scans demonstrated tumors, which correlated in all instances with the surgical findings. Microadenomas were removed from 25 patients, 22 of whom achieved postoperative remission of endocrine symptoms. Macroadenomas were found in three patients, only one of whom achieved remission after surgery. One patient had removal of an adenoma in the pharyngeal pituitary, and in another an ectopic lung carcinoid was excised; both of these patients were in postoperative remission. Four patients underwent transsphenoidal exploration but no definitive explanation was found for their hypercortisolism; these patients were not in remission. Immunohistochemical staining was performed on every specimen and all tumors showed excessive ACTH-secreting cells. A new rapid stain of the fibrovascular stroma is described.
Neurobehavioral outcome following minor head injury: a three-center study
Authors: Levin Harvey S. , Mattis Steven , Ruff Ronald M. , Eisenberg Howard M. , Marshall Lawrence F. , Tabaddor Kamran , High Walter M. , Frankowski Ralph F.
Published: May 2009

✓ The majority of hospital admissions for head trauma are due to minor injuries; that is, no or only transient loss of consciousness without major complications and not requiring intracranial surgery. Despite the low mortality rate following minor head injury, there is controversy surrounding the extent of morbidity and the long-term sequelae. The authors postulated that consecutively admitted patients who fulfilled research diagnostic criteria for minor head injury and who were carefully screened for antecedent neuropsychiatric disorder and prior head injury would exhibit subacute cognitive and memory deficits that would resolve over a period of 1 to 3 months postinjury. To evaluate this hypothesis, the neurobehavioral functioning of 57 patients was compared within 1 week after minor head injury (baseline) and at 1 month postinjury with that of 56 selected control subjects at three medical centers. Quantified tests of memory, attention, and information-processing speed revealed that neurobehavioral impairment demonstrated at baseline by all means of measurement generally resolved during the first 3 months after minor head injury. Although nearly all patients initially reported cognitive problems, somatic complaints, and emotional malaise, these postconcussion symptoms had substantially resolved by the 3-month follow-up examination. The data suggest that a single uncomplicated minor head injury produces no permanent disabling neurobehavioral impairment in the great majority of patients who are free of preexisting neuropsychiatric disorder and substance abuse.
Hormone production in clinically nonfunctioning pituitary adenomas
Authors: Black Peter McL. , Hsu Dora W. , Klibanski Anne , Kliman Bernard , Jameson J. Larry , Ridgway E. Chester , Hedley-Whyte E. Tessa , Zervas Nicholas T.
Published: May 2009

✓ Pituitary tumors in which no excess hormone secretion can be identified clinically have been considered as nonfunctioning or null-cell adenomas. Immunocytochemical data presented here suggest that many of these tumors contain subunits of the glycoprotein hormones.

Of 160 patients referred for pituitary surgery, 37 (23%) had no evidence of excess hormone secretion on preoperative endocrine evaluation. Immunocytochemical staining of these tumors was carried out using antibodies specific for prolactin, growth hormone, adrenocorticotropic hormone, the beta subunits of luteinizing hormone (β-LH), follicle-stimulating hormone (β-FSH), and thyroid-stimulating hormone (β-TSH), and the alpha subunit.

One or more of these pituitary hormones were detected in 73% of cases. The alpha and beta subunits were detected most frequently, being found in 68% of cases; 27% had staining for one or more beta subunits and 37.9% had staining for both alpha and beta subunits. The incidence was: β-FSH in 58%, β-LH in 47%, β-TSH in 33%, and the alpha subunit in 42%. Staining for multiple glycoprotein hormones was common (52%), and mixed glycoprotein hormones and prolactin cell types were found in 16% of cases. These data suggest that most apparently nonfunctioning pituitary tumors contain immunoreactive hormones and the majority of these are subunits of the glycoprotein hormones. Since the glycoprotein hormone beta subunits must combine with the alpha subunit to produce biologically active hormones, the production of the subunits alone may not have endocrine manifestations.
Effect of dexamethasone on experimental brain abscess
Authors: Schroeder Kurt A. , McKeever Paul E. , Schaberg Dennis R. , Hoff Julian T.
Published: May 2009

✓ Dexamethasone has been used to manage brain edema in patients with intracranial abscess. However, its administration has often been delayed or avoided for fear of adverse effects upon normal host responses to infection. An experimental model of brain abscess in the rat was developed to determine if dexamethasone produced adverse effects on immune competence and collagen deposition in the region of the abscess. Sprague-Dawley rats were inoculated with Staphylococcus aureus and treated intraperitoneally each day with either dexamethasone (0.25 mg/kg) or saline solution. Surviving animals were sacrificed at 4, 8, 12, or 18 days after treatment. The brains were examined grossly for abscess formation and microscopically for intensity of the inflammatory response, abscess diameter, and wall thickness.

There were no differences in mortality rates, abscess production rates, or abscess diameters when groups were compared. The intensity of inflammatory response was similar in both groups. In the group sacrificed 8 days after inoculation, a delay in collagen deposition was apparent, manifested as a thinner abscess wall in the experimental group (mean: 17.8 μ in dexamethasone-treated animals and 85 μ in saline-treated control animals: p = 1.0041). At 12 and 18 days after inoculation, there was no difference in abscess wall thickness between the control and experimental groups. Therapeutic doses of dexamethasone had little effect on mortality rates, incidence of abscess production, or intensity of inflammatory response in the experimental animals. Thus, dexamethasone did cause a delay in collagen deposition in the walls of experimental brain abscesses, but wall thickness 18 days after inoculation was not affected.
Magnetic resonance images of brain-stem encephalitis
Authors: Hosoda Kohkichi , Tamaki Norihiko , Masumura Michio , Matsumoto Satoshi
Published: May 2009

✓ The clinical and radiological findings in a case of brain-stem encephalitis are described with special emphasis on the serial magnetic resonance imaging. This pathological condition should be differentiated from brain-stem tumors, which may present with similar symptoms.
Atlanto-axial dislocation in acute rheumatic fever
Authors: Bicknell Joseph M. , Kirsch Wolff M. , Seigel Robert , Orrison William
Published: May 2009

✓ A 10-year-old boy had a sore throat, followed in 4 weeks by acute rheumatic fever and in 6 weeks by atlanto-axial dislocation. Reduction of the dislocation by means of a halo vest relieved his pain, but the cervical spine remained unstable after 3 months of immobilization and required an occiput-C1–2 fusion and rib graft to stabilize the atlanto-axial joint. This is the eighth reported case of atlanto-axial dislocation associated with acute rheumatic fever. The features of previous cases are summarized and the clinical aspects, mechanisms, diagnosis, and treatment of atlanto-axial dislocation are reviewed.
A posttraumatic lumbar spinal synovial cyst
Authors: Franck Joel I. , King Robert B. , Petro George R. , Kanzer Michael D.
Published: May 2009

✓ A patient with posttraumatic lumbar radicular paresthesias is presented. The preoperative diagnosis of an epidural synovial cyst was considered. At surgery, an epidural synovial microcystic mass was found emanating from a distracted L4-5 facet joint and dissecting into the layers of the ligamentum flavum. A brief review of the condition is presented.
Variants of radiculomeningeal vascular malformations of the spine
Authors: Cahan Leslie D. , Higashida Randall T. , Halbach Van V. , Hieshima Grant B.
Published: May 2009

✓ In recent years, it has become evident that the most common form of arteriovenous malformation to involve the spinal cord in adults is a low-flow fistula with its nidus located on the dura in relation to the dorsal nerve root. This lesion, termed “radiculomeningeal fistula” (RMF), is drained by the intradural coronal venous system and most likely causes neurological deficits due to raised venous pressure within the spinal cord. The therapy that was formerly recommended was multilevel laminectomy with microsurgical stripping of the intradural vessels. However, that procedure focused on the draining veins rather than the nidus, and it has been replaced by direct treatment of the nidus or by disconnecting the nidus from the coronal venous system. This paper reports variants of RMF's that show a wider spectrum of the clinical and radiological findings than has been previously reported. Three patients presenting with extradural venous drainage, intraspinal hemorrhage, and/or sudden non-hemorrhagic neurological decline are reported. A more complete understanding of RMF facilitates the radiological and clinical evaluation of these patients and enables the surgeon to modify the therapy in a significant way.
Interhemispheric approach for the surgical removal of thalamocaudate arteriovenous malformations
Authors: Solomon Robert A. , Stein Bennett M.
Published: May 2009

✓ A series of 250 surgically treated cerebral arteriovenous malformations (AVM's) is presented, in which 22 lesions were located primarily in the thalamus and caudate nucleus. A standardized interhemispheric approach through the posterior corpus callosum and into the atrium of the lateral ventricle was utilized for the surgical removal of these AVM's. Total removal was confirmed by angiography in 18 patients; removal was subtotal in four cases. There were no deaths in this group of patients. Disturbances of recent memory pre- and postoperatively were seen in half of the patients, but most of these deficits were temporary. Other complications included: postoperative homonymous hemianopsia (six cases), transient hemiparesis (three cases), hemisensory loss (two cases), Parinaud's syndrome (one case), and recurrent hemorrhage 2 years after surgery (one case). All 22 patients returned to their previous occupations and are leading independent lives. The results of this experience indicate that thalamocaudate AVM's can be effectively treated by resection.
Long-term results of praziquantel therapy in neurocysticercosis
Authors: Robles Clemente , Sedano Ana Maria , Vargas-Tentori Noe , Galindo-Virgen Sonia
Published: May 2009

✓ The long-term results of praziquantel therapy in 141 patients with neurocysticercosis are presented. Seventy-five patients (53%) were considered to be cured because the cysts or nodules disappeared or became calcified following praziquantel treatment and the patients were asymptomatic at the end of a 5-year follow-up period. An additional 35 patients (24.8%) improved clinically and radiographically. The intraventricular Cysticercus cysts of five patients in this group were not affected by praziquantel and had to be surgically removed. The remaining 31 patients (21.9%) were unchanged or became worse probably because, prior to therapy, Cysticercus larvae had caused tissue damage. The fact that praziquantel did not affect intraventricular cysts suggests a low concentration of the drug in the cerebrospinal fluid. Surgery continues to be an important tool in the treatment of cysticercosis to remove parasites that do not respond to praziquantel therapy as well as for the relief of intracranial hypertension.
Pain relief by electrical stimulation of the periaqueductal and periventricular gray matter
Authors: Young Ronald F. , Chambi V. Israel
Published: May 2009

✓ Pain relief following stimulation of the periaqueductal gray matter (PAG) or periventricular gray matter (PVG) in man has been ascribed to stimulation-induced release of endogenous opioid substances. Forty-five patients were studied and followed for at least 1 year after placement of chronic stimulating electrodes in the PAG or PVG to determine if pain relief due to stimulation could be ascribed to an endogenous opioid mechanism. Three criteria were assessed: 1) the development of tolerance to stimulation; 2) the possibility of cross-tolerance to morphine; and 3) reversibility of stimulation-induced pain relief by the opiate antagonist naloxone. Sixteen patients (35.6%) developed tolerance to stimulation, that is, they obtained progressively less effective pain relief. Twelve (44.4%) of 27 patients undergoing stimulation of the thalamic sensory relay nuclei for treatment of chronic pain (a presumably non-opioid mechanism) also developed tolerance. Morphine sulfate was administered in a blind, placebo-controlled protocol to 10 patients who had become tolerant to PAG-PVG stimulation and none showed evidence of cross-tolerance. Fifteen of 19 patients, already tolerant to morphine at the time of PAG-PVG electrode implantation, experienced excellent pain relief by stimulation, also indicating a lack of cross-tolerance. Twenty-two patients who experienced excellent pain relief from chronic PAG-PVG stimulation received intravenous naloxone in a double-blind, placebo-controlled protocol. Pain intensity as assessed by the visual analog scale was increased to the same degree by both placebo and naloxone. Eight patients showed no increase in pain intensity with either placebo or naloxone.

Although tolerance to PAG-PVG stimulation developed in these patients, the frequency of tolerance was similar to that seen in patients undergoing thalamic sensory nuclear stimulation. Since the latter technique presumably relieves pain by a non-opioid mechanism, the development of tolerance to PAG-PVG stimulation does not, in itself, confirm an opioid mechanism. Cross-tolerance between PAG-PVG stimulation and morphine was not seen and cross-tolerance to PAG-PVG stimulation in patients already tolerant to morphine was rare. The pain-relieving effect of PAG-PVG stimulation was reversed to an approximately equal degree by naloxone and placebo. The authors do not believe that, in most patients, pain relief elicited by PAG-PVG stimulation depends on an endogenous opioid mechanism. It appears that other, non-opioid mechanisms are primarily responsible for such pain relief.
Cerebral blood flow in patients with normal-pressure hydrocephalus before and after shunting
Authors: Vorstrup Sissel , Christensen John , Gjerris Flemming , Sørensen P. Soelberg , Thomsen Anne Marie , Paulson Olaf B.
Published: May 2009

✓ Cerebral blood flow (CBF) was measured by xenon-133 inhalation and single photon emission tomography in 17 demented patients with normal-pressure hydrocephalus before and after shunt treatment. All patients had a decreased conductance to outflow (Cout) of cerebrospinal fluid as measured by lumboventricular perfusion (COut < 0.12 ml ⋅ mm Hg−1 ⋅ min−1). Computerized tomography (CT) scanning, clinical assessment, and neuropsychological grading were performed pre- and postoperatively. The preoperative CBF studies revealed abnormal flow patterns in all patients. Fourteen patients showed moderate-sized, large, or very large central low-flow areas, and four patients had reduced flow bilaterally in the occipital and contiguous temporoparietal regions.

After shunting, six patients had a significant reduction in the size of the central low-flow area on the CBF map, agreeing well with the changes of ventricular size on the CT scan. All six patients showed an improvement in either clinical or neuropsychological grading. In 10 of the remaining 11 patients flow patterns were essentially unchanged; one patient deteriorated further. Four of these 11 patients improved on postoperative clinical or neuropsychological testing. Thus, a positive correlation was found between the changes in CBF and the reduction of the ventricular size on the CT scan, but changes in CBF as measured by the present technique did not accompany improvement in the functional state in all patients.
Effect of clot removal at 24 hours on chronic vasospasm after SAH in the primate model
Authors: Nosko Michael , Weir Bryce K. A. , Lunt Andrew , Grace Michael , Allen Peter , Mielke Bruce
Published: May 2009

✓ The efficacy of complete clot removal 24 hours after subarachnoid hemorrhage (SAH) in the prevention of chronic cerebral vasospasm was evaluated in monkeys in a blind randomized controlled trial. Twenty-four monkeys were randomized to one of three groups to undergo sham-operation (sham-operated group), clot placement only (clot group), or clot placement and removal (clot-removal group). By means of standard microsurgical techniques, the major cerebral vessels bilaterally were dissected free of arachnoid. An autologous hematoma averaging 5 gm was placed around the vessels in the subarachnoid spaces in the clot and clot-removal groups. Saline solution was instilled in the subarachnoid spaces of the sham-operated group. All animals underwent reoperation 24 hours after the first procedure. In the clot-removal group, the hematoma was evacuated. In the sham-operated and clot groups, the incision was simply closed again after 3 hours of anesthesia. Indices monitored before and 7 days after SAH induction included neurological status, angiographic cerebral vessel caliber, and arterial blood pressure. All animals were evaluated with magnetic resonance imaging (MRI); representative animals were evaluated with computerized tomography (CT) brain scans. There were no neurological deficits in either the sham-operated or the clot-removal groups. One animal in the clot group developed a progressive delayed ischemic deficit on Day 5 after SAH. A second animal in this group died suddenly on Day 4 post-SAH. An autopsy revealed a recent infarct in the territory of the superior cerebellar artery. Clinical findings correlated with MRI and CT images. Significant vasospasm (25% to 100% reduction in vessel caliber) was present on Day 7 in 100% of the clot animals (p < 0.01). There was no significant vasospasm (p > 0.05) on Day 7 in either the sham-operated or the clot-removal groups. A large volume of clot placed bilaterally resulted in a 25% incidence of delayed ischemic deficit. Evacuation of subarachnoid hematoma within 24 hours of SAH prevented the development of chronic vasospasm and delayed ischemic deficit in the primate model.
Monoaminergic responses to spinal trauma
Authors: Salzman Steven K. , Hirofuji Eikazu , Llados-Eckman Carmen , MacEwen G. Dean , Beckman Alexander L.
Published: May 2009

✓ The monoamines norepinephrine (NE), dopamine (DA), and serotonin (5-HT) and their major metabolites were measured in the spinal cord of rabbits following laminectomy or impact injury to the thoracic cord. Samples were taken 30 minutes, 60 minutes, 4 hours, and 6 weeks after injury. Utilization ratios (metabolite/transmitter) were calculated from the data. Turnover rates for NE and DA were also calculated at 30 minutes using the alpha-methylparatyrosine method. Trauma resulted in rapid and sustained elevations in 5-HT concentration at and around the injury site. The catecholamines were depleted slightly at the injury site. Levels of 5-hydroxyindole-3-acetic acid were elevated at 30 minutes but fell to baseline by 4 hours, resulting in a decrease in the 5-HT utilization ratio. The utilization and turnover of NE was increased at the injury site, while DA function was not affected. The large short-term increase in 5-HT levels may have been due to extravasation of platelet 5-HT stores into spinal tissue, rather than due to changes in neuronal 5-HT metabolism. At 6 weeks after injury, each monoamine and metabolite appeared to accumulate in spinal cord tissue proximal to the insult. Distal to the injury, depleted amine stores displayed augmented utilization. The data are discussed in terms of a serotonergic hypothesis of the progression of neural damage after trauma, with the interaction of 5-HT with raphe-spinal nerve terminals as a principal event.
Effect on intracranial pressure of furosemide combined with varying doses and administration rates of mannitol
Authors: Roberts P. Alex , Pollay Michael , Engles Charles , Pendleton Bruce , Reynolds Emery , Stevens F. Alan
Published: May 2009

✓ The first part of this study investigated the combined use of furosemide and mannitol in the treatment of elevated intracranial pressure (ICP). Two groups of dogs were studied to determine if renal excretion of mannitol was altered in the presence of furosemide. No significant difference in excretion was noted between the two groups. Fifteen animals were used in other studies to identify the most advantageous sequence of administration of furosemide and mannitol. Infusion of mannitol followed by furosemide 15 minutes later resulted in the most profound and sustained ICP reduction. The effect on ICP reduction of varying the mannitol dose was observed in studies using single doses of 0.5 gm/kg, 0.75 gm/kg, and 1 gm/kg. The larger mannitol dose, resulting in a greater blood-brain osmotic gradient, proved to be the most efficacious in ICP reduction. A further 15 animals were used in investigations to determine whether changing the rate of delivery of the most effective mannitol dose (1 gm/kg) influenced resultant ICP reduction. The results indicated that rapid administration (2 ml/kg/min) produced higher peak serum concentrations of mannitol and more profound lowering of ICP than the same dose delivered at slower rates.
Lumbosacral intramedullary myolipoma
Authors: Knierim David S. , Wacker Margaret , Peckham Norman , Bedros Antranik A.
Published: May 2009

✓ Intradural myolipoma is an unusual tumor. A case is described in which extramedullary and intramedullary striated muscle fibers caused gross contraction of a lipomatous tumor as well as of the spinal cord during electrical stimulation.
Sleep palsy (Saturday-night palsy) of the deep radial nerve
Authors: Fernandez Eduardo , Pallini Roberto , Talamonti Giuseppe
Published: May 2009

✓ A patient with a long-recognized asymptomatic lipoma adjacent to the deep radial nerve developed paralysis of this nerve from a compression similar to the sleep palsy, or “Saturday-night palsy,” mechanism.
Treatment of bilateral spontaneous dural carotid-cavernous fistulas by coils and sclerotherapy
Authors: Courtheoux Patrick , Labbe Daniel , Hamel Christian , Lecoq Pierre-Joel , Jahara Marcio , Théron Jacques
Published: May 2009

✓ A case of bilateral spontaneous carotid-cavernous fistulas producing increased intraocular pressure is reported. The fistulas lay between the meningeal branches of the internal carotid artery (ICA) and the cavernous sinus, but the ICA itself was not involved. Successful treatment was accomplished by the introduction of steel coils and a sclerotic liquid into the cavernous sinus via the distal superior ophthalmic vein.
Surgical therapy for medically intractable epilepsy
Authors: Ojemann George A.
Published: May 2009

✓ There has been a recent renewal of interest in surgical therapy for medically intractable epilepsies. Cortical resection and callosotomy are the most widely accepted modes of surgical management. The indications for each of these approaches are reviewed. Although there has been much interest in imaging techniques, including positron emission tomography, to identify epileptogenic zones, identification still depends primarily on the electroencephalogram (EEG). There are several approaches to the evaluation and intraoperative management of patients undergoing cortical resection for temporal lobe epileptogenic zones. These range from selection based on scalp interictal EEG criteria, with resections guided by electrocorticography and functional mapping, to selection based on the location of ictal onset as recorded by chronically implanted depth electrodes, with an anatomically standard resection of the temporal lobe or resection limited to amygdalohippocampectomy. No one approach provides the optimum balance of benefits to risks and costs for all patients.

The relative value of the different approaches for various populations of patients with medically intractable partial complex seizures is reviewed. Techniques for minimizing the morbidity of these operations, especially in regard to language and memory, are also discussed, as are the contributions to an understanding of the neurobiology of human epilepsy and human higher functions derived from the surgical therapy of epilepsy.
Thoracic myelopathy secondary to ossification of the spinal ligament
Authors: Yonenobu Kazuo , Ebara Sohei , Fujiwara Keiju , Yamashita Kazuo , Ono Keiro , Yamamoto Tomio , Harada Norimasa , Ogino Hiroshi , Ojima Shinzaburo
Published: May 2009

✓ The authors describe their experience with 26 cases of thoracic myelopathy secondary to hypertrophic ossification of the spinal ligament (posterior longitudinal ligament and/or ligamentum flavum). The clinical manifestations of this condition and results of its surgical treatment are described. The commonest symptoms were numbness or tingling in the legs and feet and gait disturbance. Most of the patients with involvement of the upper thoracic spine showed typical features of thoracic myelopathy: that is, sensory and motor deficits in both the trunk and lower extremities, sphincter disturbance, and exaggerated tendon reflexes. Several patients with involvement of the thoracolumbar junction presented with atypical symptoms of thoracic myelopathy and were sometimes misdiagnosed and treated inappropriately. Surgical treatment, particularly laminectomy, was not always successful. Inconsistencies in the surgical outcome were caused by either operative complications or reversal of the initial improvement during the follow-up period. The results of anterior surgery for the condition were more favorable; however, use of this procedure was rarely indicated.