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Biomedical subjects

N Klug

Publications and source records attributed to N Klug.

85 records · Page 5Linked to original sources
PubMed1985

Evoked potentials and brain stem reflexes.

The recording of evoked potentials (EPs) has become one of the most useful functional diagnostic techniques in the neurosciences during recent years. In combination with the neurophysiological investigation of brain stem reflexes (BSRs) EPs provide good information concerning circumscribed and diffuse brain and brain stem lesions. In this article the role of EPs and BSRs will be pointed out with special regard to their use in neurosurgery concerning awake and comatose patients as well. Pathological findings caused by extracerebral factors or due to neurological (systemic) and otological diseases will be discussed from the aspect of differential diagnosis only. Evoked potentials described in this paper are short latency potentials which are related to more or less defined generators in the peripheral and central nervous system. EPs of long latency seem to play a role in cognitive, affective and integrative functions of the central nervous system and they will not be dealt with in this article. In recent years an increasing number of review articles and monographs dealing with several aspects of evoked potentials has appeared [16, 17, 18, 25, 69, 80, 84, 122, 123, 124, 127, 130].

Astrocytoma↗
PubMed1984

Cerebellar infarcts in the area of the supply of the PICA and their surgical treatment.

The authors report seven cases of cerebellar infarcts in the distribution of the PICA, of whom six were treated surgically. Only one patient died and he was not operated on. Although of the remaining six patients four were comatose, and two presented obvious signs of midbrain decerebration, all of them subsequently showed a really good quality of survival. In addition to the clinical details of the cases which are set out in tabular form, a survey of the literature is given and the indications for surgical treatment discussed. The exact interpretation of the CT scan and, in this context, particularly of the brain stem and its surrounding cisterns, above all the cisterns of the quadrigeminal plate and of the vein of Galen, gives decisive help in assessing the indications for suboccipital decompressive craniotomy. In view of the small number of cases, expressing the mortality rate in percentages would seem to be pointless. However, it appears appropriate to describe our experiences of the last two years and to recommend surgical treatment.

Adult↗
PubMed1984

Decerebrate rigidity and vegetative signs in the acute midbrain syndrome with special regard to motor activity and intracranial pressure.

Decerebrate rigidity, intracranial pressure and vegetative signs were studied in 25 patients. Advanced statistical techniques were used to analyse the interrelationships between muscle activity (IEMG), blood pressure (ABP), intracranial pressure (ICP), pulse rate (HR), respiratory rate (RR), and central venous pressure (CVP) occurring during paroxysms of decerebration. The pattern of reaction is influenced by compression or stress imposed on the brain stem at the tentorial incisure and is related to the degree of cisternal obstruction. Significant differences in reaction were disclosed between provoked and spontaneous decerebration posturing.

Adolescent↗
PubMed1983

Effect of increased intracranial pressure on the blink reflex in cats.

During an acute increase in ICP produced by balloon inflation three different phases could be observed. In the first phase (ICP 40-50 mm Hg) the latencies of R 1 and R 2 showed an initial decrease followed by increase in latency. In the second phase (ICP 50-70 mm Hg) R 2 disappeared, whereas R 1 showed marked alterations, prolongation of the latency and duration, and a decreasing amplitude. In the third phase no response could be evoked. The pathophysiological observations correlated with the morphological alterations. Two ischaemic zones with BBB damage which "transsected" the mesodiencephalic and pontomesencephalic border were found. The results suggest that the disappearance of R 2 depends on rostral damage, whereas alteration of R 1 is caused by a pontomesencephalic lesion.

Animals↗
PubMed1982

Brainstem auditory evoked potentials in syndromes of decerebration, the bulbar syndrome and in central death.

The results are reported of serial brainstem auditory evoked potentials recordings in 51 patients with decerebration and bulbar syndrome. In contrast to the stability of latencies of single components of the potential in healthy subjects, patients with decerebration syndromes show considerable instability and an increase in the latency of all the components of the potential. In 34 decerebrate patients the P-I latency and the interpeak latencies for the medullo-pontine and ponto-mesencephalic segments as well as the central conduction time were significantly increased. There was marked reduction of the amplitude of P-V and P-III and deformation of the single components of the potential with widening and smoothing. The amplitude ratios A-V to A-I and A-III to A-I were significantly decreased. The findings are interpreted as due to mesencephalic and pontine functional disturbance during decerebration. The brainstem auditory evoked potential can be used to estimate the time of brain death. Possible causes of misinterpretation are discussed.

Adult↗
PubMed1982

Medulloblastoma: survey of factors possibly influencing the prognosis.

In a series of 310 cases the role of the factors age, sex, location of the tumour (midline or lateral), and medulloblastoma type (classic or desmoplastic) were analysed with regard to the prognosis. The influence of therapy is not considered because of the inhomogeneity of the material and the view nowadays that treatment is insufficient. The occurrence of lateral (or hemispheric) medulloblastomas increases in the group of the 11-15 years old patients. The proportion of the desmoplastic type is greater in adults than in children, but they are distributed almost equally medially and laterally. There seems to be no definite correlation between sex and the survival time. The mean survival time increases with age. With regard to the histological subclassification into children and adults, the mean survival times are nearly identical. The only obvious factor with a decisive influence on the prognosis seems to be the time of appearance of the tumour. Additionally, the data support the conclusion that a desmoplastic medulloblastoma should be considered as a histological variant without clinical relevance.

Adolescent↗
PubMed1982

Intracranial pressure and muscle activity in patients with decerebrate rigidity.

The authors analyse the relationship between the muscle activity during paroxysms of decerebration and the intracranial pressure. These relationships differ, and depend upon the presence or absence of mesencephalic herniation and patency of the perimesencephalic cisterns, as well as on whether the decerebration posturing has been spontaneous or induced by external stimulus. It is suggested that the magnitude of ICP reaction during decerebration is connected with the possibility of compensating the increased intracranial volume and with the strain imposed upon the brain stem at the mesencephalic level. Close correlations between the vegetative variables occuring during spontaneous DR paroxysms suggest a common excitatory neuronal mechanism. In cases when decerebration is provoked by external stimuli the response becomes more complex and not uniform.

Adult↗