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Biomedical subjects

H W Pia

Publications and source records attributed to H W Pia.

At least 19 recordsLinked to original sources
PubMed1989

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.

Animals↗
PubMed1986

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.

Brain Death↗
PubMed1986

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.

Blood-Brain Barrier↗
PubMed1986

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.

Astrocytoma↗
PubMed1985

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).

Adaptation, Physiological↗
PubMed1985

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.

Adenoma↗
PubMed1979

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.

Arteries↗
PubMed1978

Classification of aneurysms of the internal carotid system.

Microsurgery has improved the treatment of cerebral aneurysms techically and by more detailed knowledge of the topographic relations, the variations, and the anomalies of the involved arteries. A personal study of 450 aneurysms formed the basis of a modified and more detailed classification of aneurysms of the carotid system. It was confirmed that aneurysms originate at the junctions of arteries, and generally project according to the course of the vessel involved. The origins and projections aneurysms and their different sites were analyzed with the aid of angiography, angiotomography, magnification angiography, operative drawings, photographs, and films, which permitted the establishment of a special classification for every particular form. Preoperative knowledge of the types of aneurysms facilitates the surgical procedures and results in lowered morbidity.

Carotid Artery Diseases↗
PubMed1977

Aneurysms of the posterior cerebral artery. Locations and clinical pictures.

A classification of aneurysms of the posterior cerebral artery from a series of 8 personal cases and 34 cases collected from the literature is attempted. The classification is based on the topography and sites of origin of the cortical and central branches of the artery. The artery was divided into six sections which permitted the description of the origin and projection of typical aneurysms. Single cases of atypical aneurysms can be explained by the known vascular anomalies. The predilective site is section B (origins of the posteromedial choroidal artery and quadrigeminal artery), then section D with the main division of the posterior cerebral artery and origins of the anterior temporal artery, the anterior posterolateral choroidal artery, the hippocampal artery and the thalamogeniculate artery, and finally section C--the junction with the posterior communicating artery. Clinical syndromes corresponding to these locations are described. The classification, when considered together with improved angiographic technique and microsurgery, allows exact preoperative and peroperative definition of topography which in turn enables the avoidance of injury to functionally important typical and atypical central branches of the posterior cerebral artery.

Adolescent↗
PubMed1976

Sterilization of the operating microscope.

Sterilization of the operating microscope and its equipment with formaldehyde (10 g for 10 hours) in a specially developed container provides sterility and ideal storage, and secures immediate availability in daily operating theatre practice.

Microscopy↗