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PubMed1979

[Interrelationship between the basic parameters of hemo- and cardiodynamics in hypertension patients].

In examination of 541 patients with hypertensive disease and 98 practically healthy persons by means of mechanocardiography, rheography of the aorta and lung, rheovaso-, hepato-, and encephalography, and encephalography, and polycardiography, 4 types of disturbed hemodynamics were distinguished: hyperkinetic, hypokinetic, mixed, and normokinetic. Each type has characteristic signs distinguishing it from the other types and from the normal age parameters. Compared to the normal age parameters the changes in the parameters of the contractive function of the right and left ventricular myocardium and the disorders of blood supply to the liver, brain, and limbs are the most marked in the mixed and hypokinetic hemodynamic variant and less in the normokinetic hemodynamic variant.

Adult↗
PubMedDate not supplied

[Preliminary observations on computerized axial tomography (CAT) in 32 patients with various epileptic syndromes (author's transl)].

Thirty-two subjects affected by various types of epilepsy have been studied as follows: 1) from the clinical point of view with careful case history or by direct observation of the seizures; 2) from the EEG point of view by means of prolonged recordings during wakefulness and nocturnal sleep or with pharmacological activations; 3) from a radiological point of view with standard skull radiography, air-encephalography (PNX), brain scanning and, when necessary, with cerebral angiography, mono or bilateral. Furthermore, all the patients underwent a CAT at least once; in the majority of cases this examination was repeated after administration of contrast medium. The following results were obtained by comparing the various examinations: 1) anatomo-elector-clinical correlation was present only in some cases; 2) only in patients with cerebral neoplasms was there proof of an agreement in site between EEG, CAT and PNX; 3) it was not possible to detect in a definite manner epileptic glial lesions with CAT; 4) the EEG analysis, when repeated several times with different methods of investigations, whoed epileptic foci in a higher number compared to the anatomical focal lesions proved by CAT; 5) compared with air-encephalography and morphological brain scanning, CAT usually pointed out a higher number of focal and/or diffused cerebral lesions with a higher degree of precision; viceversa cerebral angiography proved to be irreplaceable in cases where it was necessary to study possible circulatory alterations.

Adolescent↗
PubMed1975

Thalamic tumors in childhood. Clinical, laboratory, and therapeutic considerations.

Eighteen cases of primary thalamic tumor occurring in children (ages 2 1/2 to 12 1/2 years) were studied retrospectively. Among the clinical features of this group that contrasted with adults having similar tumors were a shorter duration of symptoms before diagnosis and a higher incidence of motor abnormalities in the early illness. In several cases, symptoms and signs usually associated with cerebellar disorders predominated. Arteriography or gas encephalography or both were diagnostic in all but two cases. The electroencephalogram, abnormal in slightly more than 70% of the cases, suggested a thalamic mass in more than one third. A highly specific EEG feature was the presence of spindles while patients were awake. In 15 cases there was some evidence of ventricular dilation and nine of these later required shunts. In addition to shunting procedures, therapy included x-ray therapy alone or with craniotomy or craniotomy alone.

Astrocytoma↗
PubMed2000

A data fusion environment for multimodal and multi-informational neuronavigation.

OBJECTIVE: Part of the planning and performance of neurosurgery consists of determining target areas, areas to be avoided, landmark areas, and trajectories, all of which are components of the surgical script. Nowadays, neurosurgeons have access to multimodal medical imaging to support the definition of the surgical script. The purpose of this paper is to present a software environment developed by the authors that allows full multimodal and multi-informational planning as well as neuronavigation for epilepsy and tumor surgery. MATERIALS AND METHODS: We have developed a data fusion environment dedicated to neuronavigation around the Surgical Microscope Neuronavigator system (Carl Zeiss, Oberkochen, Germany). This environment includes registration, segmentation, 3D visualization, and interaction-applied tools. It provides the neuronavigation system with the multimodal information involved in the definition of the surgical script: lesional areas, sulci, ventricles segmented from magnetic resonance imaging (MRI), vessels segmented from magnetic resonance angiography (MRA), functional areas from magneto-encephalography (MEG), and functional magnetic resonance imaging (fMRI) for somatosensory, motor, or language activation. These data are considered to be relevant for the performance of the surgical procedure. The definition of each entity results from the same procedure: registration to the anatomical MRI data set (defined as the reference data set), segmentation, fused 3D display, selection of the relevant entities for the surgical step, encoding in 3D surface-based representation, and storage of the 3D surfaces in a file recognized by the neuronavigation software (STP 3.4, Leibinger; Freiburg, Germany). RESULTS: Multimodal neuronavigation is illustrated with two clinical cases for which multimodal information was introduced into the neuronavigation system. Lesional areas were used to define and follow the surgical path, sulci and vessels helped identify the anatomical environment of the surgical field, and, finally, MEG and fMRI functional information helped determine the position of functional high-risk areas. CONCLUSION: In this short evaluation, the ability to access preoperative multi-functional and anatomical data within the neuronavigation system was a valuable support for the surgical procedure.

Adult↗
PubMed2006

Robotics in neurosurgery: which tools for what?

Robots are the tools for taking advantage of the skills of computers in achieving complicated tasks. This has been made possible owing to the "numerical image explosion" which allowed us to easily obtain spatial coordinates, three dimensional reconstruction, multimodality imaging including digital subtraction angiography (DSA), computed tomography (CT), magnetic resonance imaging (MRI) and magneto encephalography (MEG), with high resolution in space, time, and tissue density. Neurosurgical robots currently available at the operating level are being described. Future evolutions, indications and ethical aspects are examined.

Humans↗
PubMed1981

Gyrate atrophy of the choroid and retina. Approaches to therapy.

Gyrate atrophy of the choroid and retina is caused by deficient activity of ornithine ketoacid aminotransferase, a pyridoxal phosphate dependent enzyme. Besides the typical eye findings, abnormalities have been found on muscle biopsy, electro-encephalography, electromyography and electrocardiography, establishing this as a generalized disorder. Ornithine is markedly elevated in plasma and other body fluids. Plasma lysine, glutamate, glutamine and creatine are reduced. The possible contributions of these biochemical disturbances to the pathogenesis of gyrate atrophy are discussed. The disease is one of the few examples of an inherited chorioretinal dystrophy whose underlying biochemical defect is known. It therefore offers a unique opportunity to develop and test rational approaches to therapy. These include lowering of the abnormally high ornithine by dietary restriction of its precursor arginine, facilitation of ornithine excretion by administration of alpha-aminoisobutyric acid, replacement of deficient products such as lysine or creatine, or increasing residual enzyme activity by high levels of cofactor (vitamin B6). The results of several studies employing such approaches to therapy are presented as well as preliminary indications of possible benefit in a few patients.

Adult↗
PubMed1982

Cerebrospinal fluid proteins and cells in normal-pressure hydrocephalus.

A total of 21 patients with normal-pressure hydrocephalus were examined. Cerebrospinal fluid (CSF) was collected before and after operation with a ventriculoperitoneal shunt. A slight plasma-like protein pattern indicating a blood-brain barrier (BBB) dysfunction was seen in 38% of the patients before operation. No characteristic changes could be found in the "CSF-specific" protein fraction. After the shunt operation 65% of the patients had a BBB dysfunction to macromolecules and 70% had two additional acidic protein bands in the CSF-specific fraction. Ventricular CSF protein content was 73% of lumbar CSF content when shunts were patent. Isotope encephalography showed a radionuclide accumulation at the intracranial part of the shunt system, indicating that the BBB damage might be located round the shunt catheter.

Blood-Brain Barrier↗
PubMed1977

Investigation of patients presenting with cerebellopontine angle syndromes.

Many neuroradiological procedures are available for the elucidation of lesions presenting with clinical evidence of a cerebellopontine angle syndrome. For 10 years we have favoured plain skull rays, sometimes supplemented by gamma encephalography, followed by angiography and have uncommonly needed further information from other contrast studies before operation. The innocuous value of computed tomography (C.T.) made it necessary to consider modification of this routine which had been found to be very satisfactory in routine practice. To obtain precise information on the diagnostic reliability and complications of the method we reviewed a large consecutive series of patients presenting with angle lesions. The radiological signs in such cases have been described many times and are well known, but our findings in a single comprehensive series emphasize the value of the method and are presented in a review. The modifications induced by CT are discussed.

Brain Diseases↗
PubMed1981

Trends in the radiological study of pituitary adenoma.

The time and place for the use of plain films of the skull, arteriography and venography, CT with and without contrast enhancement, and metrizamide cisternography as a replacement for air encephalography, for the diagnosis of the various kinds of pituitary adenomas is discussed in conjunction with a report of the experience with eight pituitary adenomas.

Adenoma↗
PubMed1987

An adaptor to the Leksell stereotaxic instrument for digital coordinate determination in radiography.

Special perspex adaptors with radiopaque reference structures have been constructed to fit to the Leksell stereotaxic instrument. These structures are visualized on X-ray film in a radiographic examination like angiography or encephalography. The films obtained in two projections at arbitrary angles and focus-film-distances are placed on a digitizing table for the determination of the stereotaxic coordinates of selected targets. The reference structures and the targets are marked with a cursor whereupon a desk top computer performs the calculation of the stereotaxic coordinates. The system allows a rapid, simple and accurate coordinate determination in stereotaxic radiography using the Leksell stereotaxic instrument.

Cerebral Angiography↗
PubMed1981

The birth and growth of neuroradiology in the USA.

Neuroradiology in the USA was started by the neurosurgeon Harvey Cushing, who personally made the first X-rays used to treat a patient with a neurological disability, and Walter Dandy, who first performed air ventriculography, ventriculoscopy, air encephalography and air myelography. The father of neuroradiology in the USA was Merrill Sosman, Cushing's associate. Modern neuroradiology was introduced into the USA from Europe by Mannie Schechter who was one of the original team of three Chief Editors of Neuroradiology.

Europe↗
PubMed1988

The determination of the local cerebral glucose utilization with the 2-deoxyglucose method.

In the adult mammalian brain, the energy metabolism is almost entirely dependent on glucose. Furthermore, a close relationship between the energy metabolism and the functional activity could be shown. Thus, the functional activity of the brain or parts thereof can be quantified by measuring the cerebral metabolic rate for glucose. Studying in vivo the fate of a radioactive labeled analogue of glucose, the 2-deoxy-D-[1-14C]glucose, and using quantitative autoradiographic techniques, it is possible to estimate the cerebral glucose utilization of every discrete brain region. The advantage of the 2-deoxyglucose method is, that the local cerebral glucose utilization represents a "metabolic encephalography" (Sokoloff 1982).

Animals↗
PubMed1976

The neuro-radiological examination of endocrine disorders of central origin in the child (precocious puberty, hypopituitarism).

The neuro-radiological findings in 38 cases of precocious puberty of central origin and 9 cases of hypopituitarism (craniopharyngiomas excepted), are reported. The radiological examination consisted of plain films of the skull and pneumo-encephalography. In the 9 cases with hypopituitarism radiological examination was normal in 4 and localised but quite diverse anomalies were discovered in 5. Out of 38 patients presenting with isosexual precocious puberty, 29 were female and 9 male. Out of the 29 girls, neuro-radiological examination was normal in 20 and showed a hypothalamic anomaly in 9. Out of the 9 boys, 8 had a hypothalamic anomaly, and only one examination was normal. In precocious puberty we found 1 ectopic pinealoma and 2 gliomas of the chiasma. In these three cases the clinical context and radiological examination made the diagnosis obvious. Masses were discovered in 7 (3 spongioblastomas and 4 heterotopias). In 2 cases (spongioblastomas) neurological symptoms were present and made an operation mandatory. In 5 cases (1 spongioblastoma, 4 heterotopias) precocious puberty was an isolated finding. It was not possible to make, on a clinical or radiological bases, a distinction between spongioblastoma and heterotopia. As time has passed the role of surgery has changed. Formerly, surgery aimed at excision of the lesion, but with advances in medical treatment surgical intervention is now directed towards biopsy and the histological study of lesions which may be treated by radiotherapy.

Adolescent↗
PubMed1994

Head surface digitization and registration: a method for mapping positions on the head onto magnetic resonance images.

We have developed a method for mapping positions on the head, such as anatomical landmarks, electrode locations, and stimulation sites, onto magnetic resonance (MR) images of the head. This method is based on the registration of two representations of the head surface: a series of contours obtained from MR images and a set of points measured from the head. The three-dimensional coordinates of each head point were acquired with the use of a magnetic digitizer, whose source was removed from the equipment and mounted on top of the subject's head. This arrangement seemed less uncomfortable for the subject than head immobilization and allowed the acquisition of many points without compromising the precision of the measurements. The digitized head surface was registered to MR image head contours using a surface registration algorithm. The registration provided the rotation and translation parameters needed for mapping head positions onto MR images. The precision of this mapping method has been estimated to be in the range of 3 to 8 mm. This method has been used to map dipole sources in electroencephalography and magneto-encephalography and to impose maps of scalp sites used in transcranial magnetic stimulation onto MR and PET images of the brain.

Adult↗
PubMed1995

An intra-arterial electrode for intracranial electro-encephalogram recordings.

A new method for intracranial monitoring of brain electrical activity by means of an intra-arterial guide wire as electrode is described. We carried out intracranial electro-encephalography (EEG) using an insulated Seeker Lite-10 guide wire 18 times in 14 patients: ten times in 6 patients with cerebral arteriovenous malformation (AVM) before embolization, and another 8 times in 8 patients with epilepsy. In all cases, a 2-5 times stronger high voltage potential EEG compared with scalp EEG could be recorded. In 3 patients with complex partial epilepsy, intra-arterial (IA) EEG was recorded under subdural strip electrode monitoring, and IAEEG at the sphenoidal portion of the middle cerebral artery was compared with subdural electrode recordings. Frequent interictal spike discharges recorded with subdural electrodes in the lesional medial temporal lobe were simultaneously visible on IAEEG recording. This method is equivalent to that using a semi-invasive electrode, but ECoG recording can be performed at angiography. IAEEG is a method of electrode recording that has the possibility of clinical application.

Adolescent↗
PubMed1979

Opto-chiasmatic arachnoiditis: a review of traditional neuroradiological diagnosis (82 cases, 1951--1976).

A retrospective appraisal of traditional neuroradiological techniques (such as direct röntgenograms, cerebral angiography RISA-cisternography, and pneumo-cisterno-encephalography, as opposed to the "new" technique of computer-assisted tomography) was carried out in a series of 82 cases of opto-chiasmatic arachnoiditis, all surgically verified. It is concluded that none of these examinations can provide a reliable diagnosis of opto-chiasmatic arachnoiditis, which preoperatively can only be a tentative diagnosis that becomes final only when confirmed by surgical findings. In the presence of certain progressive neuro-ophthalmological symptoms and signs, a negative neuro-radiological investigation should not deter the neurosurgeon from exploring the chiasmatic region. Computer-assisted tomography, of which the authors have no personal experience in these cases, may hold the future answer to the diagnostic problem.

Arachnoid↗
PubMed2002

Visualisation method of spatial interictal discharges in temporal epilepsy patients using magneto-encephalogram.

The aim of the study was to develop a method for investigating how interictal epileptic discharges in temporal epilepsy patients are activated spatially. The activity was measured using magneto-encephalography (MEG). The MEG data were used to produce a current-arrow map that reflected the topographic distribution of the electrical current for each peak epileptic waveform. A large current distribution was obtained that appeared to be contained in the limbic structure, in each temporal lobe. The large current orientation indicated two opposite directions. Furthermore, the decrease in the maximum strength of the current-arrow, depending on the medication (e.g. the decrease from 11 to 6 pT m-1 in the left temporal lobe (contralateral stimuli)), suggested that the discharge distributions could be used to verify the efficacy of medication. Thus the topographical visualisation method could be a new strategy for diagnosis in temporal epilepsy patients.

Aged↗
PubMed1997

Patterns of neuronal firing in the human lateral thalamus during sleep and wakefulness.

The firing patterns of thalamic neurons in mammals undergo a dramatic change as the animal's state changes between sleep and wakefulness. During sleep the normal tonic firing of thalamic neurons changes into a slower bursting mode characterized by repetitive activation of a low-threshold calcium (Ca2+) current. The present report describes the patterns of thalamic neuronal firing during sleep and wakefulness in one human patient. Extracellular single neuron activity was recorded during functional stereotactic surgery in the thalamus of a patient with chronic pain, who was observed to fall asleep during the recording. Evolutive power spectra of the thalamic slow wave were used in place of cortical encephalography to confirm the patient's states of sleep and wakefulness. Twenty-nine sites were observed in motor and somatosensory thalamus (Vop, Vim, and Vc) that were characterized by the presence of neurons with bursting activity when the patient was asleep. Such bursting was not observed in the patient when she was awakened. At 14 of these sites we were able to discriminate the bursting activity of single units. In each case the cell stopped firing or its bursting was replaced by a tonic firing pattern when the patient was awakened. In three cases the patient began to lapse back into sleep and the neuron resumed firing in a bursting pattern once again. None of these units had a peripheral receptive field (RF), while several other units recorded in nearby regions that did not fire in a bursting pattern during sleep had kinesthetic or cutaneous RFs. Analysis of the intraburst firing pattern revealed increasing interspike intervals (ISI) for successive action potentials in a burst and that the duration of the first ISI in the burst decreased as the number of ISIs increased. This pattern is similar to that reported to occur as a result of a calcium spike. These data have confirmed for the first time that state-dependent changes in thalamic firing exist in the human and that the physiological substrates at the thalamic level that are involved in human sleep are similar to those observed in animals.

Adult↗