The future of spinal cord stereotaxy.

The spinal cord is an integral part of central nervous system, therefore it can be expected that spinal cord has the same properties as the brain. Movement activity is realized by the activation of individual motoneurons of various spinal cord segments under the influence of analytical function of the spinal cord. When a hypothesis is accepted that the mentioned large volume of spinal cord white matter represents the entire length of neuronal network, an idea can be established that the activated motoneurons project through their reticular processes to this connecting network forming a synthetic picture of this movement and after fluent continuity the entire act of movement. Therefore, neuronal network plays the role of dynamic memory.The perspective of spinal cord stereotaxy in functional neurosurgery hypothetically enables a recognition and understanding of how brain and spinal cord communicate in movement performance (Fig. 2, Ref. 6).

The physiological conception of thinking based on the results of psychostereotactic operations.

The authors have gained their experience in psychostereotactic operations during the past 50 years. The operations were indicated in psychiatric patients on the basis of their clinical pictures. The results gained in operations of the hypothalamus, limbic system and neocortical structures of the brain were logically analysed and served as the basis for physiological conception of the function of the nervous system in the area of thinking. The elemental thinking of the hypothalamus resides in relatively simple memory that contains standard values of the internal environment of the body. The immense memory on the highest neocortical level of the human brain grew to become an independent degree of development independent of the objective reality. The entrance of physiological thinking into psychology enables to clarify the aspects of human psychology that are still liable to subjective view, such as emotions, motivation or consciousnesses (Fig. 1, Ref. 9). Full Text (Free, PDF) www.bmj.sk.

[Reflection on the physiological mechanisms of movements controlled by the spinal cord-brain interaction]. / Uvaha o fyziologickém mechanizmu pohybové reakce uskutecnované míchou na podnety z mozku.

The process of communication between brain and spinal cord remains unclear. Therefore an attempt supported by spinal cord stereotaxy was made to disclose the physiological mechanism underlying the cooperation between brain and spine as generated by the spinal cord. The initializing stimulus was the discovery of motoneuron location in all spinal cord segments providing the organic substrate for spinal cord stereotaxy. What remained to be clarified were the anatomical structures of spinal cord, participating in the feedback between brain and spinal cord. Therefore two possible hypotheses were proposed by the authors. One is closely related to the analytic-synthetic mechanism of real object and thoughts depiction in the memory of the brain and in the form of concrete ideas forming the basis for concrete thinking. In the case of spinal cord, another more probable mechanism should be considered: The process of analysis and synthesis between the participating spinal motoneurons. The mutual neuronal connections in the spinal cord are capable of depicting the movement pattern and the movement is transferred by means of the described spinal cord pathways to the memory of the brain as a concrete movement idea. From here the ideas are transferred according to the individual needs backwards by means of another described spinal cord pathways back to the spinal cord and the spinal cord is the final effector. The process of thinking is the physiological correlate of technical software, but in the form of abstract thinking it is transferred to the form of abstract thinking.

Considerations on physiological mechanisms of spinal cord movement performance according to cerebral stimuli.

The process of communication between brain and spinal cord remains unclear. Therefore an attempt supported by spinal cord stereotaxy was made to disclose the physiological mechanisms underlying the cooperation between the brain and spine as generated by the spinal cord. The initializing stimulus was the discovery of motoneuron location in all spinal cord segments providing an organic substrate for spinal cord stereotaxy. What remains to be clarified are the anatomical structures of spinal cord, participating in the feedback between brain and spinal cord. Therefore two possible hypotheses were proposed by the authors. One of them is closely related to the analytical synthetical mechanism of real objects and thoughts depiction in the memory of the brain and in form of concrete ideas it forms the basis for concrete thinking. In case of spinal cord another more probable mechanism should be considered: the process of analysis and synthesis between the participating spinal motoneurons. The mutual neuronal spinal cord connections are capable of depicting the movement pattern, and the movement is transferred by means of the described spinal cord pathways to the memory of the brain as a concrete movement idea. From here the ideas are transferred according to the individual needs backwards by means of another described spinal cord pathway back to the spinal cord, and the spinal cord is the final effector. The process of thinking is the physiological correlation of technical software, but in form of abstract thinking it is transferred to the form of abstract thinking. (Fig. 3, Ref 7). Full Text (Free, PDF) www.bmj.sk.

Is interhemispheric arachnoid cyst with corpus callosum agenesis related to cavum vergae cyst?

Authors operated on successfully giant interhemispheric arachnoid cyst associated with corpus callosum agenesis. A conclusion was drawn that this cyst was in fact expansive cavum Vergae cyst, taking into consideration the developmental mechanism responsible for the formation of third ventricle dorsal cysts (Fig. 8, Ref. 10).

Amount of introgression in flycatcher hybrid zones reflects regional differences in pre and post-zygotic barriers to gene exchange.

Introgression is the incorporation of alleles from one species or semispecies into the gene pool of another through hybridization and backcrossing. The rate at which this occurs depends on the frequency of hybridization and the fitness of hybrids and backcrosses compared to 'pure' individuals. The collared flycatcher (Ficedula albicollis) and the pied flycatcher (F. hypoleuca) co-exist and hybridize at low to moderate frequencies in a clinal hybrid zone in Central Europe and on the islands of Gotland and Oland off the Swedish east coast. Data on hatching success suggest that hybrids are less fertile in Central Europe compared to on the islands. Direct fitness estimates using molecular markers to infer paternity are consistent with the demographic data. Applying a tag-array-based minisequencing assay to genotype interspecific substitutions and single nucleotide polymorphisms we demonstrate that the amount of introgression from the pied to the collared flycatcher is higher in the two island populations (Gotland and Oland) than in two geographically distinct areas from the Central European hybrid zone (Czech Republic and Hungary). In all areas the amount of introgression from collared to pied flycatchers is very low or seemingly absent. The different patterns of introgression are consistent with regional differences in rates of hybridization and fitness of hybrids. We suggest that barriers to gene exchange may have been partly broken down on the islands due to asymmetric gene flow from allopatry. Alternatively, or in addition, more pronounced reinforcement of prezygotic isolation in Central Europe might have increased post-zygotic isolation through hitchhiking, since genes affecting pre and post-zygotic isolation are both sex-linked in these birds. One of our genetic markers appears to introgress from pied to collared flycatchers at a much higher rate than the other markers. We discuss the possibility that the introgressed marker may be linked to a gene which is under positive selection in the novel genetic background.

Neuroendoscopic management of haematocephalus.

The purpose of the paper was to publish the results of endoscopic treatment of primary and secondary haematocephalus in the group of 23 patients, treated by means of Wolf endoscopic system combined with frame based navigation with the aid of virtual reality environment. The procedure is aimed to remove blood clots from the cerebral ventricles and to reduce the volume of parenchymal haematoma in secondary haematocephalus during single surgical session. In the majority of the treated patients septostomy was added to make revision of both lateral ventricles possible from a single approach, and the operation was completed with endoscopic third ventriculostomy to reduce the amount of blood in the basal cisterns and to reestablish the patency of cerebrospinal fluid pathways, so that lumbar puncture can be safely done to facilitate the process of cleaning blood away from the cerebrospinal fluid. The surgery always facilitates the resorption of residual blood as well as blood degradation products, therefore late complications, such as posthaemorrhagic hydrocephalus, membranes and stenosis formation was prevented. Improvement of the clinical condition was obtained without the need for permanent drainage systems insertion. Lethal outcome in one patient and unfavourable clinical result in another three patients were unrelated to the endoscopic treatment. (Tab. 1, Fig. 2, Ref: 10.)

Stereotactic evacuation of spontaneous infratentorial hemorrhage with monitoring of intracerebral pressure.

INTRODUCTION: Based on our experience with stereotactic evacuation of spontaneous supratentorial hematomas this method has also been used for evacuation of spontaneous infratentorial hematoma by the transtentorial approach. MATERIAL AND METHOD: The authors present a series of 6 patients with spontaneous intracerebral hematomas evacuated by the frame-based stereotactic technique, with monitoring of intracranial pressure (ICP) during the stereotactic evacuation. This method was indicated in patients with stable neurological status according to Glasgow Coma Scale (GCS), more than 10. The frame-based stereotaxy with the Riechert-Mundinger apparatus with CT localisation of target and optimal trajectory was used. RESULTS: The presented values after stereotactic evacuation show reduction of the initial intraparenchymal ICP in all patients to values less than 20 mmHg. CONCLUSION: The measuring of the ICP and the analysis of dynamic changes during stereotactic evacuation suggest that this procedure can significantly reduce the ICP performed in connection with ICH and we believe that our results can improve management of patients with spontaneous infratentorial and supratentorial intracerebral hematoma. (Fig. 1, Ref. 21.).

[Proposal for a physiologic concept of thought based on the results of stereotaxic psychosurgery]. / Návrh fyziologické koncepce myslení odvozený z výsledku psychostereotaktických operací.

Authors have fifty years long experience with psychostereotactic surgery. On the bases of 209 operations of different types of mentally ill patients, authors built their own physiological conception of the central nervous system function. The new conception is described using block operators of thinking at the level of hypothalamus, limbic system, and neocortex in the hierarchic order. The basic physiological hypothalamic block contains two operators: stimulus evaluation and decision to act. Both operators together form reasonable, objective substantiation of thinking, which is transformed into psychological, subjective description at higher cerebral levels. New operator is added to the block diagram at the level of the limbic system: the choice of response base on experience stored in the high capacity memory. Vast neocortical memory creates a model of the individual world and it enables a new operator to be involved: prediction of the future events. Thinking, originally based on concrete images, is using abstract terms, subjected to the principles of grammar. Physiological basis of thinking enables the convergence of subjective and objective.

Abdominoinguinal pain syndrome treated by centrocentral anastomosis.

During operations in the lower part of the abdomen injuries to nerves located here arise in 1-4,2 per cent; the most frequently iliohypogastric, ilioinguinal, genitofemoral and lateral femoral cutaneous nerves. These injuries to nerves are often very painful and till to day very difficult to treat. Clinical terminology of their injuries is variable and not strict. Therefore we suggest an all embracing term "abdominoinguinal pain syndrome". The authors present four case reports, in whom centrocentral anastomosis with use of both autologous interposed segment of nerve and also without it, achieved successful treatment of chronic pain. On the basis of this experience the authors prefer centrocentral anastomosis without autologous interposed segment of nerve, which is technicaly more simple.

[A simple stereotaxic surgical apparatus]. / Jednoduchý stereotaktický operacní prístroj, SOP.

A simple apparatus based on the classical stereotactic method of surgery offers the opportunity to master miniinvasive procedures in neurosurgery and neurotraumatology. This device is particularly helpful in evacuation of intracerebral spontaneous and traumatic haematomas and in stereobiopsies, i.e. the most frequent operations in clinical practice, without the need of general anaesthesia, craniotomy and interference with cerebral tissue. The reliability of the stereotactic apparatus was positively evaluated by three independent surgeons. The apparatus was registered for use in the health services.

The function of the cerebrospinal fluid space and its expansion.

In addition to its nutritive and protective effects, the basic function of the cerebrospinal fluid space resides in dynamic equilibration of pressure fluctuations caused by volume changes in three compartments contained within the rigid skull cavity: brain tissue, blood and cerebrospinal fluid. An increase in volume in one of them brings about a compliant withdrawal in volume in the other two. The degree of cerebrospinal fluid compliance can be expressed by means of the pressure/volume index which is directly proportional to this compliance. On the other hand an expansion of fluid space which forces the brain to withdraw its tissue, brings about the dilatation of brain ventricles. The degree of their dilatation depends on the effective pressure of cerebrospinal fluid which counteracts with the resistance of brain venous collectors. The blood in the venous network of the brain and cerebral extracellular fluid play a reversible role in cerebral mass restoration and reduction. These facts explain the reason why, from the physical point of view, the brain is considered to represent a viscous and elastic spongious matter. (Ref. 21.)

[Neurosurgery--an instrument for stereotaxic surgery]. / Neurochirurgia--stereotaktický operacný prístroj.

The authors presents their experiences with simple stereotactic instrument. There are presented possibilities of using stereotactic equipment, when taking aut biopsy, from deep structures of brain, evacuation of cerebral hematoma, aspiration of the brain abscess and stereotactic quidance resection of tumor in functionally important parts of brain.

[Anatomic and functional basis for the effect of systemic hypertension on focal cerebral ischemia]. / Anatomické a funkcní predpoklady pusobení systémové hypertenze na fokální mozkovou ischemii.

Contemporary vascular neurosurgery cannot sometimes avoid electively used focal brain ischemia. In aneurysm surgery, for example, it is sometimes necessary to close temporarily the parent vessel for a safer dissection of the aneurysm sac. Also carotid endarterectomy cannot be done without a temporary closure of the artery. One of possible neuroprotective methods to be used during this controlled focal ischemia is a systemic hypertension. The knowledge of anatomical and functional capabilities of the brain circulation is crucial for understanding the advantages but also the limits of this neuroprotective method.

[Development of European medicine to the time of Vesalius (16th century)]. / Vývoj evropské medicíny do Vesalia (16. století).

Mythical Greece, Egyptian Alexandria and ancient Rome were the cradle of ancient medicine where the beginnings of anatomy and physiology were combined with nature philosophy of great personalities such as Hippocrates and Galen. A modern contribution i.e. medical chemistry, to European medicine was made by Arab physicians Rhazes and Avicena. Only when clerical dogmatism was overcome, after the discovery of the New world and the development of universities the road to scientific progress ws opened on which started the great surgeon and physician Andreas Vesalius.

[Cerebral blood flow measurement]. / Soucasné moznosti merení prutoku krve mozkem.

A cerebral blood flow measurement is an important part of studying various brain pathologies, particularly brain ischemia. The methods of measurement are still improving, although the physical substance of many of them, like Fick's or Doppler's principles, outlasts further. A change in quality in last several years came with the use of isotopes and a computer technique. New options in imaging of circulatory changes with the help of magnetic resonance technology seem to be particularly perspective. If there were no economical obstacles, this method, which is able to disclose non-invasively a brain perfusion disorder in the very beginning, would be certainly immediately applied in the broad clinical practice.

[Cerebral ischemia and neuroprotection from the viewpoint of the neurosurgeon]. / Mozková ischémie a moznosti neuroprotekce z pohledu neurochirurga.

Cerebral ischemia is a frequent and dangerous consequence of some cerebrovascular diseases. Ischaemia may be used also electively in the course of neurosurgery. Therefore new possible ways are sought how to reduce the danger of ischaemia or to prevent it. In the submitted paper some methods of neuroprotection are described and their potential or actual applicability in clinical neurosurgery are discussed. In addition to influencing the brain cell and pretentious methods in the sphere of molecular biology and genetics the induction of systemic hypertension supplemented alternatively by other methods such as hypothermia, the use of mannitol, haemodilution and hypervolaemia seem natural. A higher blood pressure helps to make leptomeningeal and cortical anastomoses patent and strengthens the collateral circulation from marginal zones of ischaemia, penumbra to the ischaemic centre and to prevent thus cerebral infarction.

[Minimally invasive treatment of traumatic cerebral hematoma. Further experience with stereotaxic evacuation]. / Minimálne invazivní zpusob osetrení traumatických hematomu mozku. Dalsí zkusenosti se stereotaktickou evakuací.

The authors summarise their experience with 16 post-traumatic cerebral haematomas which they evacuated using stereotactic technique. Based on the achieved results they reached the conclusion that stereotactically aimed treatment of haematomas is an advance, for the patient's benefit. The evacuation cannula is safely inserted to its target from a transcutaneous drill hole of the skull and thus the patient is spared the surgical trauma associated with craniotomy and further brain damage. If necessary, the focus of haemorrhage can be reached again by puncture via the channel in the bone which navigates the cannula. Surgery under local anaesthesia is rapid and the results of promising. Extension of the new method depends, however, on the availability of simple stereotactic equipment which starts to play a part in the surgery of traumatic haematomas.