Dissociation between activation of the hypothalamo-hypophyseal antidiuretic system and the type of diuresis during acute intracranial hypertension. Experimental observation.

Acute cerebral compression by a supra- and infratentorial balloon produced a triphasic pattern of diuresis. The 1st phase was characterized by polyuria associated with five fold increase of plasma (p) antidiuretic hormone (ADH) concentration, decreased urine osmolality in spite of natriuresis and blood pressure elevation. The 2nd phase was characterized by oliguria, a decrease of pADH and reduced urine Na+ concentration, whereas urine osmolality transiently increased. At this stage there was respiratory arrest and fall of blood pressure. The final stage was diabetes insipidus (DI), when EEG activity had disappeared. An increase of serum osmolality mainly occurred during the last DI phase. Serum Na+ concentration fluctuated slightly during the whole period of diuresis. These results present evidence, that the diuresis pattern reflects the hypothalamo-hypophyseal antidiuretic system (HHAS) reaction to acute intracranial pressure (ICP) increase with the vegetative symptoms of cerebral shock.

The future role of neurosurgery in the case of vascular diseases of the central nervous system.

On the basis of 2542 cerebro-spinal vascular diseases (933 aneurysms, 689 cerebro-spinal angiomas, 410 spontaneous intracerebral hematomas, 361 vascular bypass operations and 149 endarterectomies of neck vessels) the present situation and problems, as well as the future prospects of cerebral vascular neurosurgery are reviewed. It is expected that the main development will take place in the field of pathophysiology and pathochemistry of vascular diseases through the acquisition of data obtained not in experimental studies but in patients. This will refine the diagnosis and indications. It is not expected that the operative technique will undergo very substantial change. New methods in the application of laser and photosensitization techniques will be probably included in the technical armamentarium. Endovascular methods of treatment will be further developed and will lead to the limitation of the indications for direct operation. It is assumed that mortality and morbidity can be further reduced by improving the diagnosis and establishing the optimal lines of therapy.

Microsurgery of gliomas.

The author describes his microsurgical operative technique used since 1980 for gliomatous tumours. Instead of extensive resection and lobectomy, a pergyral or intergyral persulcal approach with partial gyrectomy, interhemispheric, transsylvian and transventricular exposure of the tumour surface were used. The resection of the tumour begins from its centre. In the first phase 1980-1982 bipolar coagulation, micro-sucker and pincer were used, since 1983 tumour resections have been performed with the CO2 and Nd-Yag laser and CUSA. Tumours located in functionally important regions such as the speech area, thalamus, brain stem, etc. could be removed without additional morbidity and there was a rapid improvement in neurological deficits. The early prognosis of patients harbouring these tumours is improved thanks to minimized operative trauma. The quality of life during the recurrence free period is improved and surgery of recurrence is indicated more frequently than in the past. There is no evidence that these techniques influence the length of the total survival. The use of CT and MRI improved the early diagnosis of small tumours and intraparenchymal lesions. This requires exact intraoperative localization and identification of the lesion. The technical aspects of these procedures are described. Thanks to the improvement in operative technique some limitations of surgery such as location, nature of the tumour and the age of the patient have lost much of their importance.

Brain death.

Following the research of Giessen Neurosurgery on primary and secondary lesions of the hypothalamo-pituitary system and the brainstem over a period of more than 30 years, cerebral failure and death does not represent a uniform syndrome but consists of several, well characterized syndromes of irreversible hypothalamo-pituitary, mesencephalic and bulbar failure. The specific syndromes are described in detail. The diagnosis is based on establishing complete irreversible damage of specific vital basal functions such as hypothalamo-pituitary transmission, water- and electrolyte metabolism, temperature regulation, circulation and respiration. The common feature of all types is the irreversible break-down of the complex central neurogenous and/or neurohumoral regulatory system. The permanent and irreversible loss of central regulation and modulation means at the same time the complete cessation of the specific human cortical function, the death of the whole brain. Only in bulbar failure with primary irreversible cessation of respiration artificial respiration can maintain the autonomous functions of the heart for a limited time. It is indicated when organ explantation is to be considered. Complete and irreversible isolated loss of cortical function abolishes the normal human life, but does not mean death of the remaining vegetating human being.

Giant pituitary adenomas.

Out of a series of 515 pituitary adenomas 77 giant tumours seen between 1953 and 1983 were selected and the current problems of their management discussed. Since CT became available the incidence of discovery of giant pituitary adenoma became higher at 20% against 11%, especially in elderly patients. The extent and the form of giant adenomas and the different types of expanding and invasive adenomas are described in detail. A large group--most invasive adenomas of younger aged patients comprises mostly giant prolactinomas. A second large group of expansive endocrine inactive group seems to be characteristic for older age groups. Previously reported extremely high mortality can be lowered thanks to microsurgery and in our experience also due to the use of CUSA and Laser. In this series mortality dropped from 30% to 10%, and even to 6% in the last five years. However the morbidity rate, even if transient, remained high. Operative approaches, according to site and extent are discussed. The preoperative therapy with Dopamine-agonists in form of depot-injection, may open up a new possibility of lowering the operative risk in giant prolactinomas, by reducing the tumour size and signs.

Plasticity of the central nervous system--a neurosurgeon's experience of cerebral compensation and decompensation.

Cerebral plasticity constitutes one of the most decisive factors in recovery and readaptation after cerebral lesions. In contrast to the considerable progress in current studies on normal neuronal plasticity including the idea of "l'homme neuronal", the concept of plasticity postulated by Albrecht Bethe in 1929 received little attention. The author, as a neurosurgeon, has tried to describe cranial morphological plasticity, morphological and functional plasticity in infantile encephalopathies and especially in hemiatrophic lesions. It is supposed that a true morphological substrate exists due to compensatory hyperplasia of the uninvolved hemisphere. Modern neurosurgical techniques have demonstrated that the functional plastic capacity is much larger than has been supposed, even in the elderly. Some aspects of the mechanisms of compensation and decompensation of cortical and subcortical structures as well as of the central regulation systems are discussed. The full extent of the amazing recovery and functional reorganization is reached by plastic capacity, personal motivation, adequate training and sufficient time. The contribution ends with an exposition of a personal philosophy concerning psycho-somatic dualism, the body-mind problem, the future of the human brain and the ethical outlook, based on the progressive biological evolution of the basal neocortex and the immanent functional development (H. Spatz).

Craniocervical malformations.

This short survey summarises the important craniocervical dysplasias, the malformations accompanying primary neuroectodermal and secondary lesions of the neural structures and their coverings, and complex malformations. The interpretation, classification and the identification of the static and/or dynamic biomechanical pathogenesis is a prerequisite for the correct diagnosis and for assessing the indications for and the choice of any operation to be adopted.

[Indication and efficiency of CT in neurosurgery]. / Indikation und Leistungsfähigkeit der CT in der Neurochirurgie.

Computed tomography (CT) is one of the greatest diagnostic advancements for neurosurgery. Except for angiography, the usual contrast examinations have become unnecessary. Site, extent and topography of hypodense and hyperdense lesions correlate partially with the neuropathological findings. The diagnostic value is increased by measuring the grade of density, highlight spectra, and the intravenous and intrathecal contrast injection as well as modern reconstructions. Even the smallest lesions can be found. The most important advancements in recent years are the diagnosis of blood-brain barrier disturbances and lesions of the brain stem and spinal cord.

[Principles and priorities of therapy of polytraumas in neurosurgery]. / Behandlungsgrundsätze und Prioritäten des polytraumas in der Neurochirurgie.

In polytrauma cranio-cerebral injuries are the most frequent and severe lesions. Acute haematomas and other space-occupying processes demand immediate treatment. The simultaneous operation of extracranial haematomas and haematomas of the abdomen etc. with the same priority is obligatory. The diagnostic possibilities have been discussed. Indication and time of operation of other cranio-cerebral as well as of extracranial injuries, fractures etc. are decisively influenced by the grade of hypothalamus and brain stem involvement. The present possibilities to diagnose and measure those lesions have been discussed, among them the CT-findings and the clinical signs in the different stages of polytrauma. Three cases have been cited to stress the necessity of a permanent coordinated diagnostic and therapeutic procedure.

Grading of cerebral aneurysms and the timing of operation.

The problem of acute and early operation is discussed on the basis of 630 patients with cerebral aneurysms, out of whom 50 were operated in the first week and 45 in the second week after bleeding. The mortality and morbidity for operation in the first week was significantly higher (20 per cent and 24 per cent respectively) than for operations performed in the second week after bleeding (8 and 14 per cent respectively). No certain differences, as far as the results are concerned, were found between patients operated up to the third day after the bleeding and those operated between the third and seventh day. There was a distinct correlation between the results and the grade of risk. The patients with multiple bleeds were at higher risk than patients with only one bleed. The possibility that angiography and operation provoke vascular spasm which finally leads to severe morbidity and mortality seems to be higher during the first week after the bleed than at a later stage. The figures analysed are small but speak in favour of an early operation in the second week after the bleed. However, this means that a significant number of patients may die before the operation because of recurrent haemorrhage. A far-reaching critical evaluation of acute versus early operation is necessary, as regards feasibility, indications and contra-indications.

[Traumatic intracranial haematomas (author's transl)]. / Traumatische intrakranielle hämatome.

Based on 9,000 craniocerebral traumas with 1,271 intracranial haematomas [Giessen General Surgery (n = 291) 1942-1974, Giessen Neurosurgery (n = 980) 1953-1974] distribution, diagnosis, therapy, and prognosis of traumatic haematoma has been discussed. Among 26% of the haematomas, 6.4% were extradural, 17.2% were subdural, and 2.4% were intracerebral. Mortality has decreased from 84% in the 1940's to 40% in the last decades; the least decrease (64%) being among the intracerebral haematomas. Distribution, site and size, symptomatology, and special diagnostic procedures were reported for the different types and forms of haematomas. Computer-tomography has proved to be the most decisive progress for the diagnosis, indication, timely and appropriate surgery, and follow up. The most important reasons for the still unfavourable results are lack of sufficient experience among general surgeons and traumatologists, the lack of computer-tomographs, and the need for separate clinical and angiographic diagnosis.

Large and giant aneurysms.

In a retrospective review about large and giant aneurysms of the literature and the own material (51 large and 19 giant aneurysms) the problems of distribution, diagnosis, and treatment are discussed. The present classification and interpretation are arbitrary and imprecise; size and form, site, origin, and projection have not been taken into consideration. A special analysis and a combined study of large and giant aneurysms are lacking. The own material discussed concerns distribution and classification as well as clinical and neuroradiological findings in the different locations of these aneurysms. The main locations are for large aneurysms ICA (17%), MCA (about 10%), and VBA (about 9%), and for giant aneurysms 3.5%, 3.6%, and 8.6% respectively. The relative distribution for giant aneurysms are ICA with about 50%, ACA with 20%, and VBA with 20% too. The management of giant aneurysms and to a lesser extent of large aneurysms as well is unsatisfactory. The results are discussed. The development of CT-scanning and microsurgery with arterial bypass operations and intracranial artery sutures has improved the therapeutic possibilities tremendously. Some cases are briefly discussed. The prospective personal strategy in handling large and giant aneurysms by direct attack or a combined procedure with external-internal artery bypass operation and a direct occlusion and excision in a second stage have been described. Because of the limited experience, a cooperative prospective study of interpretation, classification, clinical data, course, and therapy of such aneurysms in a representative group of patients is necessary.

Classification of vertebro-basilar aneurysms.

In continuation of earlier studies concerning the aneurysms of ICA and PCA a proposed detailed classification of vertebro-basilar aneurysms has been given. It has been proved that nearly all the aneurysms originate at the divisions of the main arteries or at the ends of large arteries as direct continuations of the main branches (BA as well as ICA). Aneurysms of the vertebro-basilar junction are of special aetiological interest. These last aneurysms are unique, and demonstrate that congenital defects seem to be more important for the origin of aneurysms than the direction of the blood flow. Origin and projection characterize the different types. Atypically located aneurysms away from arterial divisions exist, as in the ICA system. The relations between aneurysms and the multiplicity of variations and anomalies of the main arteries and the posterior part of the circle of Willis are still unknown, and should be checked in detail. Our studies have convinced us that the exact knowledge of microtopographic classification is the key to correct preoperative diagnosis, access, and treatment.