360° fixation with modern instrumentations of segment separation cervical spine injury in a 23-month-old.

In this case report clinical and technical lessons including seven years follow up learned from a flexion-distraction, highly unstable cervical spine injury causing a complete separation of C6-7 cervical segment with tetraparesis in a 23-month-old boy, are presented. To our knowledge this is the only documented case in medical literature where adult size implants (cage, plate and lateral mass screw-rod system) were utilized for cervical combined anterior and posterior internal fixation in a child under the age of two years without implant-size related problems. Seven years after the injury the child attends elementary school, can operate a wheelchair manually, and can eat and write. Computed tomography control showed no failure of the hardware and fusion was later observed in the intervertebral space of the stabilized cervical segment, however adjacent segment syndrome occurred without deterioration of the patient's status. The decision on the mode of realignment and fixation to be made in such a case was difficult because there is no standard procedure for infants.

Histopathologic evaluation of aneurysms treated with Guglielmi detachable coils or matrix detachable microcoils.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the degree of organization and fibrocellular tissue development in aneurysms treated with bare platinum or biologically active microcoils. METHODS: Twelve aneurysms were removed at autopsy between 1-18 days and another 2 between 2-3 months posttreatment. Four aneurysms were surgically removed between 6 months and 3 years following treatment. One aneurysm removed at 8 days and another at 6 months were treated with bioactive (Matrix) coils; the other 16 with bare platinum (Guglielmi detachable coils; GDCs). All specimens were embedded in plastic, stained with hematoxilin-eosin and elastin and examined by light microscopy. RESULTS: All specimens removed within 3 weeks demonstrated intra-aneurysmal thrombus, without signs of organization or fibrotic tissue formation over the neck regardless of the type of coils used. In the GDC-treated aneurysms, evidence of early thrombus organization was observed within 2-3 months, and completed yet imperfect fibrocellular reaction together with residual thrombus at 2-3 years. In the Matrix-treated specimens, the aneurysm cavity was completely filled with granulation tissue corresponding to still ongoing fibrocellular reaction at 6 months, including newly formed blood vessels, smooth muscle cells, and collagen deposition without signs of residual thrombus. CONCLUSIONS: Our results indicate that in aneurysms treated with bare platinum coils thrombus organization does not occur until late after treatment and may remain imperfect for years. In one aneurysm studied 8 days following treatment with Matrix coils, no difference was noted compared to aneurysms treated with bare platinum coils. In another aneurysm examined 6 months following packing with Matrix coils, the histologic changes support the hypothesis that the biologically active polymer may accelerate aneurysm healing.

Speech activation SPECT and plasticity of language networks.

Neuronal activity might be measured by regional cerebral blood flow (rCBF) Single Photon Emission Computed Tomography (SPECT) as there is a close relationship between neuronal activity and rCBF changes. In order to study the hemispheric dominance for language and the plasticity of language networks by measuring the rCBF rest and language activation SPECT studies were performed in the presurgical evaluation of ten right-handed and two left handed patients with brain lesions of the dominant hemisphere. A special group of hemisphere-specific neuropsychologic tasks were used for activation, after a proper psychologic conditioning. The rCBF results were calculated by comparing the rest and activation SPECT data using a special regions of interest program and asymmetry index (AI). We compared the results of speech-activation to the results of clinical, morphological (MRI), and postoperative data. In controls, significant activation was found in Brodmann's area 44 and 45, contralateral cerebellum, superior middle and posterior temporal gyrus. In patients, additional regions of activation were seen in contralateral frontal and temporal regions, and in ipsilateral temporal region. AIs of the cerebellum demonstrated a negative correlation with hemispheric dominance for language. In conclusion, significant changes in rCBF in or adjacent to the eloquent areas with various patterns of rCBF changes of the additional regions demonstrate the close relationship between neuronal activity and cerebral blood flow, that can be measured by SPECT.

Loss of Calbindin-D28K immunoreactivity from dentate granule cells in human temporal lobe epilepsy.

The loss of the calcium binding protein, Calbindin-D28k, from dentate granule cells has been observed in different animal models of epilepsy and in ischaemia. This decrease is accompanied by alterations of calcium and N-methyl-D-aspartate currents, which may explain the hyperexcitability of the dentate gyrus. In the present study, we found a loss of calbindin immunoreactivity from over 90% of the dentate granule cells in lobectomy samples from four of 10 temporal lobe epilepsy patients. In another four patients, over 50%, of dentate granule cells were devoid of calbindin immunoreactivity, whereas the remaining two cases showed a 20-30% decrease. Electron microscopy revealed a normal ultrastructure both in calbindin-containing and calbindin-negative granule cells. Both calbindin-positive and -negative mossy fibre collaterals participated in supragranular sprouting. As inferred from data in animal models, the lack of calbindin in dentate granule cells of human epileptic subjects is likely to result in hyperexcitability of the dentate gyrus, which may then function as a "motor" for seizures.

Changes in the distribution and connectivity of interneurons in the epileptic human dentate gyrus.

The distribution, size, dendritic morphology and synaptic connections of calbindin-, calretinin- and substance P receptor-positive interneurons and pathways have been examined in control and epileptic human dentate gyrus. In the epileptic dentate gyrus, calbindin-containing interneurons are preserved, but their dendrites become elongated and spiny, and several cell bodies appear hypertrophic. The relative laminar distribution of calretinin-containing cells did not change, but their number was considerably reduced. The calretinin-positive axonal bundle at the top of the granule cell layer originating from the supramammillary nucleus expanded, forming a dense network in the entire width of the stratum moleculare. Substance P receptor-immunopositive cells were partially lost in epileptic samples, and in addition, the laminar distribution and dendritic morphology of the surviving cells differed considerably from the controls. In the control human dentate gyrus, the majority of substance P receptor-positive cells can be seen in the hilus, while most are present in the stratum moleculare in the epileptic tissue. Their synaptic input is also changed. The extent of individual pathological abnormalities correlates with each other in most cases. Our data suggest, that although a large proportion of inhibitory interneurons are preserved in the epileptic human dentate gyrus, their distribution, morphology and synaptic connections differ from controls. These functional alterations of inhibitory circuits in the dentate gyrus are likely to be compensatory changes with a role to balance the enhanced excitatory input in the region.

Regional brain concentrations of neurotensin following amygdaloid kindled and cortical suprathreshold stimulation-induced seizures in the rat.

There is now considerable evidence that putative neuropeptides are involved in epileptogenic processes. Neurotensin (NT), which affects neuronal excitability in many parts of the CNS, is potentially relevant to the kindling phenomenon, but has not previously been studied in the kindling model of epilepsy. This study compared the short term (24 hr) and long term (3 wk) effects of amygdaloid kindled seizures, and the short term effects of non-kindled seizures (cortical suprathreshold stimulation-induced seizures, STS), on the concentrations of NT in 13 brain regions in the rat. Whereas kindled seizures produced neither short term nor long term changes in NT, the STS resulted in altered NT concentrations, with a decrease in the cortex and increases in the hippocampus and cervical spinal cord. These results reveal seizure-type specific changes in NT in 3 brain regions; and indicate that although NT does not appear to be involved in kindling, it may be important in the neurochemical mechanisms underlying STS.

Contralateral approach to bilateral and ophthalmic aneurysms.

In a previous survey, we found a high incidence of fatal rupture of an unclipped aneurysm in patients with multiple aneurysms. To deal with this problem, we introduced a more vigorous technique that accesses aneurysms previously considered unapproachable during one operating session. Attempts were made to clip middle cerebral and ophthalmic aneurysms contralateral to the operative exposure. We have successfully clipped contralateral aneurysms of the posterior communicating artery when bilateral aneurysms were present. We have also used this contralateral approach successfully with single ophthalmic and proximal carotid aneurysms that pointed medially. We review the cases of 39 patients with 43 intracranial aneurysms operated from the contralateral side and present the surgical technique in relation to the angiographic findings.

Surgical experiences with giant intracranial aneurysms.

A series of 35 patients with 36 giant aneurysms is presented. Thirteen patients presented following subarachnoid hemorrhage (SAH) and 22 with evidence of a space-occupying lesion without recent SAH. The preferred technique of temporary trapping of the aneurysm, evacuation of the contained thrombus, and occlusion of the neck by a suitable clip is described. The danger of attempted ligation in atheromatous vessels is stressed. Intraoperatively, blood pressure was adjusted to keep the general brain circulation within autoregulatory limits. Direct occlusion of the aneurysm was possible in over 80% of the cases. The mortality rate was 8% in 36 operations. Six percent of patients had a poor result. Considerable improvement in visual loss was evident in six of seven patients in whom this was a presenting feature, and in four of seven with disturbed eye movements.

Transoral surgery for craniocervical space-occupying processes.

Although the number of reports concerning the transoral approach to anteriorly placed lesions of the craniocervical junction are increasing, the development of this technique is still in its early stages. The indications and surgical methods vary widely, and there is much room for discussion of the technical details. Eight cases operated on via transoral surgery during the last 4 years are presented in support of the transoral approach to tumors in the craniocervical region.

Management of pineal region tumours.

Pineal region tumours represent a colourful, challenging peculiarity of brain pathology. Views on their management are still much divided and controversial. Data of fifty patients with the whole palette of these tumours seen in the National Institute of Neurosurgery have been analysed in view of the result of management versus histology of these tumours. Findings of tumour marker studies have not at all been conclusive in predicting histology and outcome, however, cytology of the cerebrospinal fluid (CSF), if positive, pointed toward a very gloomy management result in all cases. Merits of infratentorial-supracerebellar, occipito-transtentorial approaches of direct surgery, palliative interventions and their timing, as well as that of irradiation are discussed in comparison with opinions and arguments from the literature. Shunt procedures alone proved to be dangerous in some cases by evoking haemorrhagic complications. In carefully selected cases microsurgical intervention gave the best possible results in expansively growing pineal region tumours. There is still place for irradiation and chemotherapy, again, in certain types of mass lesions.

Automatisms with preserved responsiveness and ictal aphasia: contradictory lateralising signs during a dominant temporal lobe seizure.

The 25-year-old right-handed woman suffering from temporal lobe epilepsy (TLE) was referred to our centre for presurgical evaluation. MRI showed a right-sided hippocampal sclerosis. During video-EEG-recorded seizures, abdominal aura was followed by oral automatisms, during which she was completely reactive to external stimuli, although she was unable to speak. Ictal EEG showed right temporal seizure pattern, without contralateral propagation. She had abnormal speech postictally. Speech-activated functional transcranial Doppler sonography revealed right-sided speech dominance. She has become seizure free after a right-sided amygdalo-hippocampectomy. In our patient, contradictory clinical ictal lateralising signs (automatisms with preserved responsiveness vs. ictal and postictal dysphasia) occurred during right-, speech-dominant-sided seizures. This is the first report when automatisms with preserved consciousness occurred during a seizure originating and involving the speech-dominant hemisphere.

Arterial and respiratory influences on intracranial pressure in infancy.

Ventricular and subdural pressures have been monitored in 23 infants. Pressure waves which were influenced by respiratory and cardiac activity were noted. These were rather long lasting and were influenced more by respiration than by cardiac activity, when the intracranial pressure is low. Respiration and arterial pressure have similar effects when the intracranial pressure is normal, but when the intracanial pressure is increased the effects of respiratory activity are diminished.

Transoral surgery for basilar impression.

A patient with basilar impression presented with a progressive myelopathy due to odontoid invagination. It was thought that a posterior decompression would be hazardous; therefore, the inferior clivus, odontoid process, and anterior arch of the atlas were removed transorally. We have found that, even with symptoms of long duration, marked improvement can be expected when the operation is targeted to the actual abnormality. In such cases, analysis of craniocervical tomograms will show the direction of medullary compression and thus indicate the correct surgical approach.

Early surgery for ruptured cerebral aneurysm.

Preliminary experience with 150 consecutive cases of ruptured cerebral aneurysms operated on within 48 hours is reported. The rationale of this emergency procedure is to prevent early rerupture and also to prevent neurological ischaemic consequences of the subarachnoid haemorrhage likely to develop in the first week after a rupture. The acceptable outcome of the surgically treated cases (87% excellent and good outcome) has been favourably matched to those of a group of equal number of consecutive cases seen in suitable condition for surgery within 48 hours by medical personnel but that remained unoperated for various reasons. The incidence of delayed neurological ischaemia as the definite cause of death is lower in the group operated on in the acute stage than those with delayed surgery, although the overall incidence of clinical vasospasm does not seem significantly lower than in the delayed surgery group.

Metabolism of anti-herpes agent 5-(2-chloroethyl)-2'-deoxyuridine in mice and rats.

The enzymatic splitting and metabolic elimination of anti-viral agent 5-(2-chloroethyl)-2'-deoxyuridine [CEDU] have been studied. For elucidation of structures of metabolites, several different kinds of extraction, purification and spectroscopic methods were used (Extrelut LC, TLC, HPLC, MS, NMR, IR, UV and CD). For mass spectral analysis, various ionization techniques (EI, CI and FAB-MS) were performed as complementary methods. After oral administration of [14C]-CEDU to mice and rats, the parent compound, 5-(2chloroethyl) uracil [CEU] and hydroxylated CEU metabolites were isolated and identified from urine and faeces by the above mentioned methods. The CEDU showed rapid phosphorolysis in vitro with thymidine phosphorylase Km 41.0 +/- 5.0; and uridine phosphorylase Km 10.0 +/- 1.5. The cleavage of the N-glycosidic bond of the nucleoside analogue and a new metabolic pathway of CEDU [stereoselective oxidation of 5-(2-chloroethyl) uracil] was observed in both species.

[Neurosurgery using the Gamma Knife]. / Gamma-kés idegsebészet.

Gamma Knife radiosurgery is a neurosurgical technique dedicated to treat a wide spectrum of intracranial pathologies. Radiosurgery is a method employing a single fraction of high dose ionizing radiation beams focused on the stereotactically defined intracranial target volume through the intact skull. This precise irradiation of intracranial volumes can necrotize the targeted cell mass--as in treatments of tumors and functional syndromes--or may induce certain biological effects in the target tissue-as in treatments of AVM's and epilepsy--without imposing a significant risk on the neighboring intact neural tissues. The clinical application of Gamma Knife includes a wide range of neurosurgical indications, such as treatments of arteriovenosus malformations, pituitary adenomas, craniopharyngiomas, meningiomas, vestibular schwannomas, gliomas, metastatic tumors, as well as functional neurosurgical syndromes, such as trigeminal neuralgia, extra-pyramidal dysfunctions, epilepsy, pain- and psychiatric syndromes. The clinical effect of irradiation is not immediate, it becomes detectable on follow up studies after a few months. The application of the technique is determined by the histological type, size and location of the pathology. Gamma Knife has evolved to become an established alternative to opened cranial surgery in certain cases with low morbidity and no mortality, offering a safe neurosurgical treatment for inoperable as well as operable lesions that carry significantly high surgical risk. In our review we present the technical and radiobiological principles, clinical indications, limitations and outcome results of this method. Our data are based on the practice and results of the Lars Leksell Center for Gamma Surgery, Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, USA (Director: Ladislau Steiner dr.).

[In vitro interaction of selegiline, riboflavin and light. Sensitized photodegradation of drugs. I]. / Szelegilin, riboflavin és fény in vitro kölcsönhatása. Fotoszenzibilizált gyógyszerbomlások. I.

Selegiline (Deprenyl, Jumex, Movergan etc.) is primarily used in the therapy of Parkinson's disease due to its neuroprotective, antidepressive and oxidative stress-preventing activities. Its prime effect is based upon the inhibition of the monoamine oxidase enzyme (MAO-B). The cofactor of this flavoenzyme is riboflavin (vitamin B2). Riboflavin, on the other hand, is an effective photosensitizer, with the capacity to promote the photodegradation of molecules (drugs, biological systems) which are otherwise stable against daylight. It has been studied whether this property of riboflavin is expressed against selegiline as well. This experiments proved that in the presence of riboflavin, both daylight and the light of daylight-lamps are sufficient to significantly decompose selegiline. The major decomposition product is methamphetamine.

Thromboembolic complication induced stable occlusion of a ruptured basilar tip aneurysm. Case report and review of the literature.

We describe a case of a ruptured basilar bifurcation aneurysm that thrombosed during preparation for endovascular therapy as a complication of diagnostic angiogaphy, and showed a favorable evolution during long-term follow-up. Endogenous thrombosis of ruptured, non giant aneurysms is uncommon. The persistence of occlusion over time in such cases is not well established. Two weeks after rupture, a 6 x 8 mm basilar bifurcation aneurysm was referred for endovascular treatment. During preparation for endovascular coil occlusion, without having any endovascular material at the level of the basilar artery, a complete thrombotic occlusion of the basilar bifurcation and aneurysm was observed. Given the good collateral circulation for both posterior cerebral arteries no thrombolysis was undertaken. The early follow-up of seven days, three and six months showed a complete recanalization of the basilar artery and remodeling of the basilar bifurcation. The 20 months imaging follow-up demonstrated a small aneurysm regrowth at the prevoius location that remained stable during the follow-up of seven years. Unchanged biological and hemodynamic characteristics. however, may pose an elevated risk of a new aneurysm formation over time, making long-term imaging follow-up, and in case of progression, aneurysm occlusion necessary for the patient.