bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of mechanical factors in the pathogenesis of short-term and prolonged spasm of the cerebral arteries
Authors: Arutiunov Alexander I. , Baron M.A. , Majorova N. A.
Published: May 2009

✓ The authors describe fibrous structures they name “chordae” that stabilize the position of arteries in cerebral subarachnoid spaces. The innervation of these structures and their relation to the innervation apparatus of the arterial wall is discussed. Animal experiments and human autopsy material were used to study the role of the stabilizing structures in the pathogenesis of arterial spasm following the rupture of saccular aneurysms. Mechanical stimuli produced short-term but not prolonged arterial spasm.
Arteriopathic complications during treatment of subarachnoid hemorrhage with epsilon-aminocaproic acid
Authors: Sonntag Volker K. H. , Stein Bennett M.
Published: May 2009

✓ A review of arteriopathic complications in three of seven patients receiving epsilon-aminocaproic acid (EACA) is presented. All seven patients with subarachnoid hemorrhage due to ruptured aneurysm were receiving EACA in the presurgical treatment period. Each of the three patients showed cerebral arteriographic changes resembling arteritis or intravascular thrombosis, and a deteriorating clinical course.
Surgical treatment of basilar artery aneurysms
Authors: McMurtry James G. , Housepian Edgar M. , Bowman Frederick O. , Matteo Richard S.
Published: May 2009

✓ The authors report a technique to aid in the surgical treatment of patients with basilar artery aneurysms. Under moderate hypothermia a nondominant temporal craniotomy and small anterior temporal lobectomy are performed. After median sternotomy is done and ventricular fibrillation is induced, microscopic dissection around the aneurysm proceeds for 4 minutes. If more time is needed, manual cardiac systole is performed for 60 seconds. This has been repeated for as long as 28 minutes, with an average of 9 minutes of arrest. After the aneurysm has been treated, normal sinus rhythm is restored in the heart. The operative technique and 12 case histories are presented. There were two deaths among the early cases. All others have done well.
Surgery of intact intracranial aneurysms
Authors: Jain Kewal K.
Published: May 2009

✓ The author reports his experience with 15 cases involving intact intracranial aneurysms. The most common symptom was headache; less common symptoms were seizures and cranial nerve involvement. Twelve patients were treated surgically without any operative mortality or morbidity. Relief of headaches occurred in the eight patients in whom the aneurysm was clipped or the carotid artery was ligated in the neck. It is recommended that most intact intracranial aneurysms be treated surgically. Certain contraindications are discussed.
Streptokinase clot lysis time in patients with ruptured intracranial aneurysms
Authors: Geronemus Robert , Herz David A. , Shulman Kenneth
Published: May 2009

✓ Antifibrinolytic therapy using epsilon aminocaproic acid (EACA) was administered to 34 patients with subarachnoid hemorrhage, 27 of whom had aneurysms. The streptokinase clot lysis time (SCLT) was used as an index to determine whether patients were receiving adequate doses of medication. Two days of continuous intravenous treatment with 30 to 36 gm per day of EACA were usually required to achieve therapeutic range, as judged by the SCLT. With continued monitoring, doses could then be reduced to as low as 24 gm per day, depending on the requirements of each individual. The authors believe that EACA therapy with SCLT monitoring is valuable in the early conservative treatment of subarachnoid hemorrhage pending definitive aneurysmal surgery.
Functional localization in the trigeminal root
Authors: Pelletier Valmore A. , Poulos Dennis A. , Lende Richard A.
Published: May 2009

✓ The composition of the trigeminal root was determined in this study by a combination of electrophysiological recording and stimulation of dissected root fibers in macaques, evaluation of deficits in man after posterior fossa root section, and microdissection in man and macaque. The roots in man and macaque were found anatomically similar. The sensory root contained three distinguishable but overlapping divisions with fibers relating to various peripheral functions and surfaces mixed within each division; no separate region contained fibers of a particular function, and no pattern of somatotopic localization could be determined within a division. The motor root contained sensory proprioceptive fibers, activated by jaw movement, and were found closely intermingled with motor fibers in all fascicles dissected. Accessory fibers (Dandy) were present in all dissections in man and macaque. They contained the same motor and sensory elements as the motor root which they joined. Human partial root sections via the posterior fossa did not exclusively diminish any single sensory modality, and an explanation is offered for the observation that generous surgical sections often result in only slight sensory loss.
Trigeminal neuralgia treated by differential percutaneous radiofrequency coagulation of the Gasserian ganglion
Authors: Nugent G. Robert , Berry Bruce
Published: May 2009

✓ The authors describe surgical and anesthetic techniques for the treatment of trigeminal neuralgia by radiofrequency coagulation. Using radiographic landmarks derived from a stereotaxic study of 54 cadaver skulls, they delineate lateral and anteroposterior guidelines which aid in the percutaneous penetration of the foramen ovale. Controlled lesions can be made selectively in any division of the trigeminal nerve. The procedure has been effective in abolishing pain usually with preservation of touch sensation in the face. The percutaneous operation has the added advantage of a short hospitalization, usually 2 days. Of the 65 patients treated, only one still has the pain of trigeminal neuralgia. In six instances the procedure had to be repeated because insufficient sensory deficit was produced by the initial lesion. Three patients have developed anesthesia dolorosa; however, none has developed facial paralysis.
Herniated cerebellar tonsils and cough syncope
Authors: Larson Sanford J. , Sances Anthony , Baker John B. , Reigel Donald H.
Published: May 2009

✓ Two patients with cough syncope and herniated cerebellar tonsils apparently of congenital origin are reported. Neither had hydrocephalus or any evidence of neoplasm. Tests were done in one patient during coughing: the resting cerebrospinal fluid pressure fell; the transmitted pulse pressure waves disappeared; hypotension, bradycardia, and occipital headache developed; and evoked potential amplitude was markedly reduced. All findings returned to control values within 2 minutes. After suboccipital craniectomy and upper cervical laminectomy, neither patient has had recurrence of cough headache or of cough syncope. A mechanism for this event is suggested.
Spontaneous carotid - cavernous fistula produced by ruptured aneurysm of the meningohypophyseal branch of the internal carotid artery
Authors: Obrador Sixto , Gomez-Bueno Juan , Silvela Javier
Published: May 2009

✓ The authors report a case in which the cause of a “spontaneous” carotid-cavernous fistula could not be demonstrated by selective angiography of external and internal carotid arteries. However, postmortem study of the cavernous sinuses revealed an unsuspected ruptured aneurysm of the internal carotid artery at the origin of the meningohypophyseal branch.
A technique for supine myelography
Authors: Herskowitz Allan , Graebner Robert , Naidech Howard
Published: May 2009

✓ A technique for obtaining supine views during myelography is described which uses foam rubber pads to support the patient and thus obviates the need for removal and reinsertion of the spinal needle.
Cerebral circulation and metabolism
Authors: Langfitt Thomas W.
Published: May 2009

✓ Selected papers of particular interest to neurosurgeons and neurologists, which were presented at the June, 1973, International Symposium of Cerebral Circulation and Metabolism in Philadelphia, are summarized and discussed.
Stereotaxic surgery for cerebral palsy
Authors: Balasubramaniam V. , Kanaka T. S. , Ramanujam P. B.
Published: May 2009

✓ An analysis of 94 cases of cerebral palsy treated by stereotaxic surgery is reported. The selection of patients and target areas for surgery are discussed. Hypertonic cases are classified into rigid, rigidospastic, and spastic types on the basis of surface electromyographic studies. For rigidity and rigidospasticity, ventrolateral thalamotomy gives relief, while spastic cases do well with dentatectomy. Centromedian thalamotomy relieves sensory-induced involuntary movements. Involuntary movements unaccompanied by changes in tone are abolished by lesions of the nucleus ventralis intermedius.
Temporary cortical blindness following angiography
Authors: Horwitz Norman H. , Wener Louis
Published: May 2009

✓ Temporary cortical blindness as a complication of posterior angiography is reported in 11 patients and compared with 30 similar cases previously reported. Theoretical considerations of etiology implicate transitory alterations of the blood-brain barrier in the striate cortex.
Normal cerebrospinal fluid pressure
Authors: Gilland Olof , Tourtellotte Wallace W. , O'Tauma Lorcan , Henderson William G.
Published: May 2009

✓ The authors report studies of cerebrospinal fluid (CSF) pressure in 31 young normal volunteers. In half, a 22-gauge needle was used, and in the other half a 26-gauge needle. The opening CSF pressure was monitored for 10 minutes and also in some during the CSF withdrawal period and the 10-minute CSF reformation period. Cardiac CSF pulse amplitudes and Queckenstedt responses following the opening pressure-monitoring period were also recorded before and after the fluid withdrawal. The average opening pressure was 14.5 cm of 0.15 M sodium chloride (S.D., 3.7) with the 22-gauge needle, and 15.7 cm (S.D., 3.6) in subjects receiving the 26-gauge needle. In each subject the opening pressure tended to fluctuate around a characteristic individual level; in five perfectly relaxed normal volunteers an average value of 20 cm was observed, with a maximal value of 24 cm. The amplitude of the cardiac pulse had a direct relationship to the individual CSF pressure.

CSF was withdrawn at two different rates; both withdrawal rates generated approximately linear pressure decay curves. When the withdrawal rates were 5 and 1 ml/min, the average decline of pressure at the end of the period was 9.2 and 5.2 cm respectively. The mean CSF pressures increased only slightly during the 10-minute CSF reformation period. The data obtained should help to define whether a young adult patient does indeed have a CSF pressure elevation.
Interrelationship between blood pressure and regional cerebral blood flow in experimental intracranial hypertension
Authors: Shalit M. N. , Cotev S.
Published: May 2009

✓ The interrelationship between systemic blood pressure (BP), regional cerebral blood flow (rCBF), and intracranial pressure (ICP) was investigated in two experimental models of intracranial hypertension in cats. In one group, ICP was raised by the inflation of an extradural balloon; in the other, brain swelling was produced. The effects of raised blood pressure on rCBF and ICP in the two groups differed considerably. In the “brain-swelling” group, elevated BP had no beneficial effects on rCBF. When ICP approached diastolic BP, an increase in BP was followed by a marked increase in ICP and a decrease in rCBF. Therefore, the elevated BP often observed in extreme intracranial hypertension (Cushing response) cannot be regarded as a beneficial, compensatory defense mechanism, but rather as a deleterious phenomenon.
Pressure in the sagittal sinus during intracranial hypertension in man
Authors: Martins Albert N. , Kobrine Arthur I. , Larsen Douglas F.
Published: May 2009

✓ Intracranial pressure (ICP) and sagittal sinus pressure (SSP) were measured simultaneously in 12 patients with brain tumors and secondary intracranial hypertension (ICH). In nine, the mean SSP was largely unaffected by changes in ICP. In three, SSP changed with the ICP. In all but one patient, the ICP remained higher than SSP and, as the ICP increased, the difference between the two also increased. Sinograms performed during ICH demonstrated partial collapse of the sinuses in some patients and not in others. The mean SSP in adults with brain tumors appears to respond unpredictably to changes in ICP. Since the rate of cerebrospinal fluid drainage depends upon the gradient between ICP and SSP, intracranial spatial compensation is probably influenced by the response of SSP to ICP. Individuals with gradients that rapidly increase because their sinuses do not collapse probably compensate more rapidly than those whose sinuses do collapse. This assumed difference in the rate of spatial compensation may account for some of the variability of the ICP response to an enlarging intracranial mass or a change in cerebral blood volume.
Experimental identification of the subarachnoid and subpial compartments by intracranial pressure measurements
Authors: Schettini Alfonso , Walsh Edward K.
Published: May 2009

✓ Because of the range of pressures associated with the intracranial system, correct interpretation of epidural intracranial pressure measurements requires an accurate means of measuring the pressure, the depth at which the pressure is measured, and the region of the system associated with that depth. A measurement system is described that provides such an accurate pressure/depth determination and maintains a uniform rate-of-insertion of the pressure transducer; the latter provision is important because of the viscoelastic behavior of the brain tissue. Use of these experimental methods to determine the pressure in three distinct intracranial regions is described, namely, in the subarachnoid and the subpial compartments and a transitional region between these two.
Acid-base balance and arterial and CSF lactate levels following human head injury
Authors: King Lionel R. , McLaurin Robert L. , Knowles Harvey C.
Published: May 2009

✓ Sequential arterial and cerebrospinal fluid (CSF) lactate, pH, pCO2, HCO3−, and pO2 levels were determined for 4 days in 17 patients immediately following uncomplicated head injury. Lactate was initially markedly elevated in both fluids and decreased by the third day after injury. There was mild arterial metabolic acidosis and respiratory alkalosis on admission; the alkalosis continued. Arterial pO2 was below normal at all times. The CSF showed a normal pO2, and metabolic acidosis related to lactate accumulation. Blood and CSF pCO2 and HCO3− levels equilibrated well, probably because of the time factor; CSF and arterial pO2 levels were not significantly related. The clinical implications of CSF lacticacidosis after head injury are discussed.
Extracranial skeletal metastases from an intracranial meningeal chondrosarcoma
Authors: El-Gindi Sayed , Abd-El-Hafeez Mohamed , Salama Mamdouh
Published: May 2009

✓ This report describes a meningeal chondrosarcoma over the convexity of the brain with extracranial metastases to the left femur and pelvis.
Failure of buffered 5-hydroxytryptamine to increase brain capillary permeability to albumin in monkeys
Authors: Solomon Lewis S.
Published: May 2009

✓ The effect of buffered 5-hydroxytryptamine (5-HT) on the blood-brain barrier to 125I-albumin was studied in 14 rhesus monkeys. Buffered 5-HT was introduced into the lateral ventricle by ventriculocisternal perfusion, resulting in a concentration gradient in the periventricular tissue from 1 to 800 times endogenous levels. Buffered 5-HT failed to induce an increase in periventricular vascular permeability to 125I-albumin. The author suggests that previous contrary reports from other laboratories may have resulted from species differences and failure to control certain physiological parameters including the use of highly acidic 5-HT preparations.
Effects of antifibrinolytic and steroid therapy on the contused spinal cord of cats
Authors: Campbell James B. , DeCrescito Vincent , Tomasula John J. , Demopoulos Harry B. , Flamm Eugene S. , Ortega Bienvenido D.
Published: May 2009

✓ A 400 gm-cm force exerted on the exposed spinal cord of the cat led to its progressive destruction by hemorrhage and edema. Intravenous administration of epsilon aminocaproic acid (EACA) and methyl prednisolone sodium succinate (MP) appreciably protected the tissue of the spinal cord by minimizing hemorrhage and edema. At 24 hours, a spinal cord so treated compared favorably with an untreated control specimen removed 2 minutes after trauma. Success with this combined medication was attributed to steroid stabilization of neural cell membranes and the lysosomes contained therein. Thus, edema was partially prevented, as well as escape of proteolytic enzymes. It was the latter group of enzymes that led to propagation of hemorrhages and nervous tissue destruction; EACA inhibited their action.
The topography and variability of the primary visual cortex in man
Authors: Stensaas Suzanne S. , Eddington Donald K. , Dobelle William H.
Published: May 2009

✓ The topographical anatomy of the primary visual cortex in man was studied by macroscopic identification and measurement of the line of Gennari on coronal sections from 52 hemispheres collected at autopsy. Computer analysis of these data provided detailed, quantitative information concerning the amount, variability, and distribution of the striate area on the surface of the occipital lobe, and within the calcarine fissure and other sulci. This information is particularly applicable to the development of a functional visual prosthesis for the blind based on stimulation of the visual cortex. Taking conservative values for two-point discrimination (3 mm) on the cortex based on previous observations made during neurosurgical operations, and the surgically accessible areas available for stimulation reported in this study, it seems clear that a useful number of electrodes could be implanted in virtually every patient.
Spinal epidural cyst: theories of pathogenesis
Authors: Lake Peter A. , Minckler Jeff , Scanlan Robert L.
Published: May 2009

✓ The pathogenesis of spinal epidural cyst is reexamined in the light of a case in which a small drop of contrast medium introduced by myelography 23 years before had become entrapped within a noncommunicating spinal epidural cyst. This finding suggested the diagnosis prior to surgery and reinforces the hypothesis that original communication with the subarachnoid space may later be obliterated. Two alternative theories are discussed.
Nonprogressive calcified mass of the skull involving nine cranial nerves: 36-year follow-up
Authors: Scott Michael
Published: May 2009

✓ A case is reported in which a calcified mass in the posterior and middle fossae produced unilateral involvement of nine cranial nerves but 36 years later showed no evidence of progressive enlargement or increase in neurological deficit.
Lacunar skull deformity (Lückenschädel) and intelligence in myelomeningocele
Authors: Stein Sherman , Schut Luis , Borns Patricia
Published: May 2009

✓ Clinical and radiographic records of 156 children with myelomeningocele and adequate follow-up were reviewed to assess the relationship of lacunar skull deformity (Lückenschädel, or LSD) to intellectual development. LSD was present on perinatal films in 54.5% of these children. On later testing the group with LSD achieved a mean IQ of 63.8 as opposed to 95.8 found in children without LSD. The difference is very highly significant (p < 0.0005). Since the presence or absence of LSD is easily determined at birth, it can be used as an early indicator of intellectual capacity. Signs of hydrocephalus at birth were not found to be reliably associated with either LSD or eventual IQ. The significance of these findings and the relationship between LSD and defective cerebral development are discussed.
Intracranial hemorrhage in infants due to acquired Prothrombin complex deficiency
Authors: Visudhiphan Pongsakdi , Bhanchet Parttraporn , Lakanapichanchat Chintana , Chiemchanya Surang
Published: May 2009

✓ The authors report eight infants who had acute intracranial bleeding after the third week of life, in the absence of known trauma. When first seen each was moribund, pale, and had a tense anterior fontanel; half of the cases had associated ecchymoses. Spinal and subdural taps yielded large amounts of bloody fluid. Coagulation studies indicated a severe lack of factors involved in prothrombin complex formation. The clotting indices were sufficiently low to account for spontaneous bleeding. Satisfactory clinical and laboratory results were demonstrated after subdural and spinal taps combined with intravenous vitamin K and fresh blood transfusion to correct the coagulation defect and anemia.
Ventricular perfusion in cats with kaolin-induced hydrocephalus
Authors: Eisenberg Howard M. , McLennan James E. , Welch Keasley
Published: May 2009

✓ Cats were made hydrocephalic by cisternal instillation of kaolin. Three to 8 weeks later it was found by perfusion between the ventricular system and the spinal subarachnoid space that communication had been reestablished through a demonstrably dilated central canal of the spinal cord. Absorption of fluid from the ventricular system, measured both by ventriculospinal perfusion and, after ligation of the spinal cord, by perfusion between the lateral ventricles, was found to be indistinguishable from zero over a wide range of ventricular pressure.
Aseptic meningitis following posterior fossa surgery in children
Authors: Carmel Peter W. , Fraser Richard A. R. , Stein Bennett M.
Published: May 2009

✓ The results of suboccipital craniectomy for varying types of posterior fossa pathology in 50 children are reported. Thirty-five (70%) experienced aseptic meningitis postoperatively, with spiking fever and meningismus; cerebrospinal fluid (CSF) studies revealed pleocytosis, high protein values, and depression of glucose. The absence of bacterial pathogens in serial CSF cultures distinguishes this syndrome from septic meningitis. Aseptic meningitis does not respond to antibiotics, but steroids in suitable doses will modify or suppress the clinical and CSF picture. This syndrome may predispose to postoperative hydrocephalus, but steroid therapy may diminish this risk.
Recurrent sciatica associated with herpes simplex
Authors: Morris Harold H. , Peters Bruce H.
Published: May 2009

✓ A case of recurrent sciatic pain associated with herpes simplex infection is presented and the characteristic differences from usual forms of sciatica discussed. Special features of this entity are recurrent episodes of neuralgic pain followed by zosteriform skin eruptions. Both rash and pain disappear within a few days. This entity should be considered when evaluating patients with recurrent sciatica.
Effect of experimental ischemia on cerebral water and electrolytes
Authors: Shibata Shobu , Hodge Charles P. , Pappius Hanna M.
Published: May 2009

✓ In dogs, while the middle cerebral artery (MCA) was clipped, an apparent ischemia was demonstrated with fluorescein angiography when the dye was injected through the lingual artery. Injection of fluorescein into the femoral artery or perfusion of carbon black particles through the heart demonstrated considerable collateral blood supply to the affected area. Water, sodium, and potassium content of cerebral tissues normally supplied by the occluded artery remained unchanged. At 48 hours after clipping, focal areas of infarction developed in 70% of the animals; edema could then be demonstrated in tissue surrounding the infarction. The collateral blood supply was compromised by subjecting the dogs with clipped MCA to hemorrhagic hypotension for 1 hour. Following restoration of the systemic blood pressure by infusion of the shed blood, an area of ischemia in the territory normally supplied by the clipped artery could be easily demarcated by fluorescein angiography through the femoral and lingual arteries and by carbon perfusion. The involved cerebral cortex tissue showed marked changes that started immediately after restoration of the blood pressure, and which consisted of a fall in percentage dry weight and potassium content and an increase in sodium content. These findings were clearly correlated with gross and histological evidence of massive necrosis and were interpreted as indicating cell death rather than tissue swelling. In the underlying white matter, moderate delayed changes in water and electrolyte content were compatible with the development of vasogenic edema.
Intraocular and optic nerve sheath hemorrhage in cases of sudden intracranial hypertension
Authors: Muller Paul J. , Deck John H. N.
Published: May 2009

✓ The eyes of 23 patients with sudden intracranial hypertension were studied at post-mortem. Intraocular hemorrhage had occurred in 37% and optic nerve sheath hemorrhage in 87%. Expansion of the optic nerve sheath, particularly the fusiform retrobulbar portion, was a consistent finding. The subdural space of the optic nerve sheath bore the brunt of the hemorrhage which sometimes communicated with perivascular intradural hemorrhages. Optic nerve sheath hemorrhage is shown to result from rupture of dural and bridging vessels of the optic nerve sheath; this we conclude is subsequent to optic nerve sheath dilatation caused by the transmission of intracranial pressure through the subarachnoid communication between the optic nerve sheath and the intracranial cavity. Intraocular hemorrhage is the result of retinal venous hypertension and rupture brought on by obstruction of both the central retinal vein and the retinochoroidal anastomosis.
Vitreous hemorrhages and sudden increased intracranial pressure
Authors: Vanderlinden R. Graham , Chisholm Lionel D.
Published: May 2009

✓ Six cases of bilateral hemorrhage into the vitreous body related to intracranial hypertension are presented. Four were associated with ruptured cerebral aneurysms, and the others followed head injury. The onset of vitreous hemorrhage was delayed in all cases, and in five patients subhyaloid hemorrhages were present from 2 to 27 days prior to their extension into the vitreous. Visual acuity was greatly reduced. The ophthalmoscopic and slit lamp appearance of the vitreous are described. The hemorrhages usually cleared spontaneously within 24 months, and vision returned to normal. Surgical treatment to remove residual vitreous blood in selected cases is outlined.
Experimental intracerebral hematoma
Authors: Sussman Bernard J. , Barber Jesse B. , Goald Harold
Published: May 2009

✓ Intracerebral hematoma was simulated in 16 dogs. Oxygen tension was measured in the adjacent cerebral parenchyma, fourth ventricle, and cervical subarachnoid space by both microelectrode and sampling techniques in the course of four different studies. Determinations of intracranial pressure and the pH, pO2, pCO2 of arterial blood and cerebrospinal fluid (CSF) were made. Reductions of oxygen tension were encountered uniformly, both in brain parenchyma and CSF, following the induction of intracerebral hematoma. There was an associated acidosis in the CSF compartment. The findings cannot be explained on the basis of increased intracranial pressure or reduced cerebral perfusion. The acidosis may be related to the metabolic effects of blood as well as tissue hypoxia. The changes suggest additional reasons for the evacuation of intracerebral hematomas in man.
Primary reconstruction of depressed frontal skull fractures including those involving the sinus, orbit, and cribriform plate
Authors: Nadell Joseph , Kline David G.
Published: May 2009

✓ Instead of discarding bone as in past practice with depressed skull fractures, fragments were soaked in Betadine, trimmed, reinserted into the skull defect, and covered with flaps of pericranium, muscle, or fascia. Of the 110 patients who had bone replaced, 65 had frontal fractures, which in 33 involved the frontal sinus, cribriform plate, or orbital rim. Fractures involving sinuses were treated by exenterating the sinus and packing it with muscle. The frontal and orbital rim region were reconstructed whenever possible with a mosaic of replaced bone. There were no deaths due to the minimal complications from the procedure. Despite severely macerated, contaminated, and in several instances, infected scalp wounds, most bone fragments have survived, and cranial defects have gradually filled with new bone. The authors believe that immediate bone replacement for depressed frontal fractures with or without orbital, sinus, or cribriform plate involvement is both practical and safe.
Neurophysiological effects of dorsal column stimulation in man and monkey
Authors: Larson Sanford J. , Sances Anthony , Riegel Donald H. , Meyer Glenn A. , Dallmann Donald E. , Swiontek Thomas
Published: May 2009

✓ In 18 patients with cancer and intractable pain, capacitatively coupled pulses of 0.25 msec duration were delivered transcutaneously at 100 Hz to sets of five in-line electrodes implanted subdurally over the dorsal columns. Averaged somatosensory-evoked potentials were recorded from scalp electrodes before, during, and after application of current. All but one patient experienced relief of pain during stimulation, persisting for as long as several hours afterward. Eleven patients developed hyperactive deep reflexes, pathological reflexes, and decreased perception of joint rotation, pain, and touch below the level of current application. Somatosensory-evoked potential amplitudes were markedly reduced. All neurological findings returned to control values within 1 hour after each of repeated applications of current. Histological examination of spinal cord sections from four cancer patients showed no changes secondary to long-term current application.

Similar currents were applied to the spinal cord of 15 monkeys with chronically implanted bipolar recording or stimulating electrodes over the lower, middle, and upper thoracic cord, in nucleus ventralis posterior lateralis (VPL), and over the sensory motor cortex (SMC). With application of current, the responses in VPL and SMC to peripheral stimulation were abolished. Evoked potential responses were abolished between bipolar stimulating electrodes and bipolar recording electrodes separated by the five in-line electrodes used to supply the 100 Hz current. However, when both stimulating and recording electrodes were either above or below the five in-line electrode set, evoked responses were unaffected. The findings indicate that applied currents blocked neuronal transmission by producing local changes in the cord. The prolonged alteration of cerebral evoked potentials and relief of pain, however, could also be related to involvement of supraspinal neurons.
Spinal fluid and blood serum enzyme activity in brain injuries
Authors: Klun Boris
Published: May 2009

✓ Four enzymes have been investigated in spinal fluid and blood serum in two series of humans with varying degrees of brain injury. The values have been compared to those in a series of animals with standard experimental brain lesions. The enzymes studied showed high values, usually corresponding to the clinical severity of the injury, but not all figures are statistically significant. The highest values were found between the second and the ninth day following injury. The ultimate possibility of practical quantitative evaluation of brain injuries is discussed.
Extreme-lateral lumbar disc herniations
Authors: Abdullah A. F. , Ditto Edward W. , Byrd Edward B. , Williams Ralph
Published: May 2009

✓ The authors believe that posterior lumbar disc herniations that occur far laterally (beneath, or beyond the facet) present a clinical picture and special problems of diagnosis different from those encountered with the usual herniations within the spinal canal. In a series of 204 consecutive disc operations, there were 24 “extreme-lateral” disc herniations at the second, third, or fourth lumbar interspace, none at the lumbosacral joint. When compared with the incidence of posterior herniations above the fourth interspace, it appeared that “extreme-lateral” herniations were responsible for the majority of second, third and fourth lumbar root compressions. The clinical syndrome is characterized by anterior thigh and leg pain, absent knee jerk, and sensory loss in the appropriate dermatome but also by the absence of back pain, typical back signs, or positive Lasegue's sign. Reproduction of pain and paresthesia by lateral bending to the side of the lesion is a reliable diagnostic sign. The authors report that myelography fails to disclose these lesions, while discography often proves helpful.
Myxoosteochondroma in the pons
Authors: Ishii Ryoji , Sato Susumu , Ueki Komei , Oyake Yo
Published: May 2009

✓ A case is reported in which a myxoosteochondroma of the pons was successfully removed subtotally.
Accessory middle cerebral artery
Authors: Watanabe Tohru , Togo Makoto
Published: May 2009

✓ An accessory middle cerebral artery was demonstrated in the carotid angiograms of four patients; it originated from the horizontal portion of the anterior cerebral artery, and in two, gave rise to perforating arteries. None of the accessory arteries was associated with an intracranial aneurysm or anomaly of the central nervous system.
Ganglion of the peroneal nerve
Authors: Cobb Cully A. , Moiel Richard H.
Published: May 2009

✓ Peroneal nerve ganglion masquerades as other lesions and may not be diagnosed except at operation; it can be treated by surgery. Two cases are reported and the literature summarized.
Technique for obtaining iliac bone graft for anterior cervical fusion
Authors: Nicholson Maurice W.
Published: May 2009

✓ Modifications in the operative technique for removing bone dowels from the iliac crest for anterior cervical interbody fusion are described. The technique has been successful in alleviating hip pain following graft removal.
Suction-irrigation treatment of craniotomy infections
Authors: Erickson Donald L. , Seljeskog Edward L. , Chou Shelley N.
Published: May 2009

✓ A simple method of early debridement and institution of suction-irrigation has been used on eight consecutive craniotomy infections. The principles of treatment are identification of the infecting organism, open debridement of the wound, and closed irrigation of the subgaleal area with an antibiotic solution for 5 days. The treatment has been, thus far, uniformly successful in resolving these craniotomy infections, thereby avoiding bone flap removal.
Experimental cerebral vasospasm
Authors: Nagai Hajime , Suzuki Yoshiaki , Sugiura Mitsuo , Noda Satoshi , Mabe Hideo
Published: May 2009

✓The authors describe a model for making an experimental subarachnoid hemorrhage that closely simulates human aneurysmal rupture. A needle previously inserted into the posterior communicating artery is subsequently withdrawn by traction on a thread. Using this model they demonstrate biphasic spasm by measurement of cerebral blood flow and angiography after rupture of the artery; the early spasm lasted 60 minutes and the late spasm began 3 or 4 hours after subarachnoid hemorrhage and continued for several days. The authors discuss the pathogenesis of early and late spasm.
Role of prostaglandin F2 in human cerebral vasospasm
Authors: Torre Emanuele La , Patrono Carlo , Fortuna Aldo , Grossi-Belloni Daniela
Published: May 2009

✓Prostaglandin (PGF2α) concentrations were measured by radioimmunoassay in serial samples of CSF from patients with subarachnoid hemorrhage, in an attempt to correlate these values with the presence or degree of the arterial spasm. Although elevated concentrations of PGF2α were found in most of these patients, when compared with a control series, there was no correlation between these values and the appearance of cerebral vasospasm. The results are discussed with reference to previous experimental work suggesting a role of PGF2α in the pathogenesis of cerebral vasospasm.
Comparative effectiveness of alpha-blockade and beta-stimulation in modifying experimental basilar arterial spasm
Authors: Smigiel Mitchell R. , Sundt Thoralf M.
Published: May 2009

✓The comparative effectiveness of isoproterenol (Isuprel), phentolamine (Regitine), and phenoxybenzamine (Dibenzyline) in modifying basilar arterial spasm induced by the topical application of arterial blood was studied in cats. None of these agents was effective in inhibiting initial peak constriction. Each reduced the duration of the vasospasm. The results indicate that both alpha-blockade and beta-stimulation can alter the course of blood-induced cerebral vasospasm.
Cerebral blood flow measurements and electroencephalograms during carotid endarterectomy
Authors: Sundt Thoralf M. , Sharbrough Frank W. , Anderson Robert E. , Michenfelder John D.
Published: May 2009

✓ Ninety-three endarterectomies for carotid stenosis were monitored with cerebral blood flow (CBF) measurements, and 113 with both CBF measurements and a continuous electroencephalogram (EEG). Significant CBF increase occurred only when carotid endarterectomy was for a stenosis greater than 90%. A high correlation between CBF and EEG indicated when a shunt was required. To sustain a normal EEG, the CBF ascertained by the initial slope technique must be 18 ml/100 gm/min at an arterial carbon dioxide tension (PaCO2) of 40 torr. The degree of EEG change below this level during occlusion reflected the severity of reduced blood flow and was reversible with replacement of a shunt. The value and limitations of these monitoring techniques and a concept of ischemic tolerance and critical CBF are discussed.
Atheromatous disease of the carotid artery
Authors: Houser O. Wayne , Sundt Thoralf M. , Holman Colin B. , Sandok Burton A. , Burton Robert C.
Published: May 2009

✓Angiograms of patients who underwent carotid artery surgery were correlated with the surgical findings, cerebral blood flow measurements, and the following manifestations of cerebral ischemia: amaurosis fugax, transient cerebral ischemia,small completed infarct, generalized cerebral ischemia, and progressing stroke. The degree of carotid stenosis and presence of ulcerating plaques and soft thrombi could be predicted accurately; tiny ulcerations were not angiographically identifiable in the presence of severe stenosis. Generalized cerebral ischemia corresponded closely with severe degrees of bilateral carotid stenosis or unilateral occlusion in conjunction with contralateral stenosis. Internal carotid to middle cerebral artery slow flow was found in many patients with a progressing stroke or an unstable neurological state. Retrograde ophthalmic flow was found frequently in symptomatic patients with high-grade stenotic lesions at the origin of the internal carotid artery. Localized alterations included small vessel occlusion, retrograde collateral flow, avascular areas, focal slow flow, and reactive hyperemia and were correlated with symptoms of focal cerebral ischemia.
Effect of systemic arterial hypotension on the rate of cerebrospinal fluid formation in dogs
Authors: Carey Michael E. , Vela A. Richard
Published: May 2009

✓The rate of cerebrospinal fluid (CSF) production in dogs was measured by ventriculocisternal perfusion with artificial CSF containing inulin. In normotensive animals, the average CSF production was 36 ± 6 µl/min. When the mean arterial blood pressure was reduced to 62 ± 1 mm Hg, the CSF production fell to 22 ± 5 µl/min, a 39% reduction in fluid formation. The authors briefly discuss various hypotheses to explain this reduction.
Subcutaneous reaction to silicone in ventriculoperitoneal shunts
Authors: Sugar Oscar , Bailey Orville T.
Published: May 2009

✓Silicone tubing (Silastic) used for ventriculoperitoneal shunts induces a fibrous connective tissue sheath around the tubing in children and adults. Two children examined 8 and 3 years after subcutaneous implantation showed a complete tube of dense fibrous connective tissue around the silicone tubing. The reaction was entirely quiescent. These tubes of connective tissue were apparently capable of conveying cerebrospinal fluid for some months after the silicone tubing was disconnected from the pump or pulled out of the abdomen.
Aseptic meningitis due to spontaneous rupture of craniopharyngioma cyst
Authors: Patrick Bernard S. , Smith Robert R. , Bailey Terry O.
Published: May 2009

✓The authors report a case in which spontaneous extravasation of the contents of a supracellular cyst produced aseptic meningitis.
Some issues in health education and delivery of health care
Authors: French Lyle A.
Published: May 2009

✓ The president of the American Association of Neurological Surgeons (AANS) discusses the delivery of health care, its availability, accessibility, and affordability. He stresses the physician's responsibility for leadership in the various sociological aspects of health maintenance.
Cerebral circulation time with ruptured intracranial aneurysms
Authors: Okawara Shige-Hisa , Kimura Jun , Hahn Joo Y.
Published: May 2009

✓ The cerebral blood circulation time (CT), including the length of the arterial phase, was obtained from rapid serial angiograms in 114 patients with ruptured intracranial aneurysms. The average CT of 7.2 sec, with a mean arterial phase of 3.1 sec, was much longer than the normal average CT of 5.4 sec with its 2.4 sec arterial phase. Longer circulation times were observed with the higher Botterell grades of clinical condition, high arterial perfusion and CSF pressures, and in cases with angiographic evidence of arterial spasm, hematoma, or hydrocephalus. Values of CT greater than 8.0 sec were associated with increased mortality and morbidity and vice versa. The value of the cerebral blood circulation time as a guide to preoperative treatment and to the prognosis of cases of ruptured intracranial aneurysm is suggested.
Acute subdural hematomas of arterial origin
Authors: O'Brien Paul K. , Norris John W. , Tator Charles H.
Published: May 2009

✓ Five cases of acute subdural hematoma associated with bleeding from cortical arteries are described. In the four cases in which the affected vessel was examined histologically, there was a defect in the arterial wall secondary to avulsion of a small surface twig, which had apparently been traversing the subdural space. The possible mechanisms for damage to the vessel wall and the role of this arterial bleeding in subdural hematomas are discussed.
Surgical treatment of nerve root compression caused by scoliosis of the lumbar spine
Authors: Epstein Joseph A. , Epstein Bernard S. , Lavine Leroy S.
Published: May 2009

✓ Effective relief of radicular pain and recovery of function is reported in four elderly patients with lumbar scoliosis following surgical decompression of the lateral recesses of the spinal canal. The operation includes laminectomy or hemilaminectomy with unroofing of the lateral recesses and foramina by medial facetectomy or facetectomy. The patients tolerated surgery without morbidity, were walking within 2 or 3 days, and recovered without incident. The pathological anatomy and operative criteria are discussed.
Effect of experimental cervical spinal cord injury on respiratory function
Authors: Kadoya Satoru , Massopust Leo C. , Wolin L. R. , Taslitz N. , White R. J.
Published: May 2009

✓ The effect on respiratory function of crushing the C-4 level of the cervical spinal cord was evaluated in monkeys. Spontaneous respiration ceased immediately after the crush due to direct mechanical trauma, but could be recovered provided a respirator was used and certain areas of the anterolateral columns remained intact. This acute respiratory paralysis occurred even in minimally damaged cords in which most of the anterolateral columns were spared, and led to death due to hypoxia if a respirator was not used. The delayed spinal cord swelling due to edema and centrifugal pressure from an expanding central cord lesion gradually caused delayed respiratory paralysis; durotomy relieved the pressure effects and markedly facilitated recovery.
Normal-pressure hydrocephalus
Authors: Stein Sherman C. , Langfitt Thomas W.
Published: May 2009

✓ After shunting, 43 patients with normal-pressure hydrocephalus were followed for 6 to 30 months. All patients had complete preoperative clinical evaluations, pneumoencephalograms, and isotope cisternography; in addition, 21 had saline infusion studies, and 15 had biopsies. Of the 10 patients in whom the etiology of the hydrocephalus was known eight (80%) were significantly improved. Of the other 33 patients, 21 (64%) showed some improvement; this was substantial and sustained in only eight (24%). The whole series of patients with idiopathic normal pressure hydrocephalus was divided into two groups on the basis of shunt response and the relative predictive values of preoperative tests. No significant association was found between the results of shunting and preoperative clinical factors, pneumoencephalography, isotope cisternography, saline infusion tests, or various combinations of clinical and laboratory abnormalities. The significance of these findings is discussed.
Antibiotic neurotoxicity
Authors: Weiss Martin H. , Kurze Theodore , Nulsen Frank E.
Published: May 2009

✓ By ventriculocisternal perfusion, a series of newer antibiotics were circulated through the central nervous system to ascertain the potential toxicity of these drugs to the nervous parenchyma. Ampicillin, carbenicillin, gentamycin sulfate, and polymyxin B sulfate appear to be well tolerated whereas cephalexin monohydrate and penicillin G caused a repeated pattern of significant CSF pleocytosis, histological evidence of periventricular perivascular infiltrates, and evidence of clinical toxicity. A regime for treatment of central nervous system infections is presented, derived from the data presented above. Preliminary experience in a clinical series appears to support this program.
Suprasellar germinomas: diagnostic confusion with optic gliomas
Authors: Cohen David N. , Steinberg Martha , Buchwald Robert
Published: May 2009

✓ The authors report a case in which a suprasellar germinoma (ectopic pinealoma) was mistakenly interpreted as an optic glioma. The proper diagnostic and therapeutic procedures for the management of this lesion are discussed, emphasizing recognition of the characteristic triad of visual loss, hypopituitarism, and diabetes insipidus, as well as verification by biopsy and adequate radiation therapy.
Disappearance and reappearance of cerebral aneurysm in serial arteriograms
Authors: Spetzler Robert F. , Winestock David , Newton Hans T. , Boldrey Edwin B.
Published: May 2009

✓ A case is reported in which a left frontopolar artery aneurysm was demonstrated, disappeared, and then reappeared in a series of angiographic studies obtained during the conservative management of two episodes of subarachnoid hemorrhage. Only 23 days separated the first and last angiograms; three days later the aneurysm was successfully clipped.
Ependymal-choroidal cells in cerebrospinal fluid
Authors: Wilkins Robert H. , Odom Guy L.
Published: May 2009

✓ Samples of cerebrospinal fluid removed from 66 patients with various non-neoplastic disorders during pneumoencephalography or ventriculography were examined cytologically using the method of Millipore filtration. In addition to leukocytes and other types of cells, clumps of ependymal or choroidal cells were frequently noted; they were found most often and in greatest numbers in hydrocephalic infants. The authors hypothesize that these cells are constantly being shed and replaced, especially during infancy, and that their exfoliation is increased if the ventricles are stretched by hydrocephalus. It is important that one recognizes the nature of these clumps of ependymal or choroidal cells to avoid misidentifying them as leukocytes or tumor cells.