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At least 19 recordsLinked to original sources
PubMed1977

Brain death.

Brain death occurs whenever there is involvement of higher centers such as Cerebral Cortex and Thalamus (unresponsiveness and deep coma) and Brainstem and Basal ganglionic structures (loss of spontaneous respiration all cranial nerve, and postural reflexes). Involvement of Spinal Cord is less constant. Drug intoxication should be excluded. An electroencephalogram may be done but what is paramount is the physician's clinical judgment. The medico-legal implications of brain death is less complicated than it is generally presumed to be. It is extablishment of the legality of brain death concept that is crucial. This allows the physician to use his judgment to implement the law.

Brain Death↗
PubMed1992

Acute endocrine failure after brain death?

After brain death, 32 potential organ donors were studied to determine serum and plasma concentrations of hypothalamic-pituitary hormones, thyroid hormones, and cortisol over a period of up to 80 hr. Diagnosis of brain death was established either on the basis of clinical criteria (n = 16) or by angiography (n = 16). While 78% of the organ donors developed diabetes insipidus, none of the circulating hormones of the anterior pituitary gland showed a progressive decline in concentration according to their plasma half-lives. With the exception of arginine vasopressin (AVP), no hormone concentration was found to be subnormal due to the onset of brain death. The subnormal free triiodothyronine (FT3) values in 62% of cases (median FT3 of 2.2 pmol/L within the first 24 hr) and the cortisol concentration of 6.9 micrograms/dl correlate with the frequency of similar findings in patients with severe head injuries. While the adrenocorticotropic hormone (ACTH) concentrations of 10-53 pg/ml remained constant during the study period, thyroid-stimulating hormone (TSH) and human growth hormone (hGH) concentrations showed a 12- and 35-fold increase from baseline values after 30-40 hr. These results suggest that, despite the now generally accepted criteria of brain death, there is still some residual function, and thus also perfusion of the hypothalamic-pituitary neuroendocrine system. This residual function appears to be sufficient to maintain hormonal plasma levels at least in the low reference range in most donors. Hormonal depletion in organ donors subsequent to brain death, as suggested repeatedly in the literature, could not be confirmed. The analysis of serum or plasma concentration patterns of a number of hormonal parameters following brain death does not support the rationale for a routine replacement therapy of total triiodothyronine (TT3) or cortisol to maintain endocrine homeostasis prior to organ harvest. However, dexamethasone therapy may be followed by suppression of the adrenal cortex of the organ donor. In these cases, cortisol substitution may be indicated.

Adrenocorticotropic Hormone↗
PubMed1992

The undulating toe flexion sign in brain death.

Brain-dead patients may exhibit gross spontaneous and reflex movements (e.g., Babinski sign, stereotypic flexion of one or more limbs, and Lazarus sign). We report three brain-dead patients who had unusual complex sequential movements of the toes. Undulating toe flexion was elicited by noxious stimuli to the lower extremities, and consisted of initial plantar flexion of the great toe, followed by sequential brief plantar flexion of the second, third, fourth, and fifth toes. The undulating toe flexion sign differs from previously described responses characterized by plantar flexion of the toes (e.g., Rosselimo's sign and the Mendel-Bechterew sign) in that it consists of complex patterned sequential movements of the digits rather than brief simultaneous flexion and/or fanning of the toes. Neurologists should be aware of this unusual finding, which should not preclude the diagnosis of brain death.

Adult↗
PubMed1976

Auditory brain-stem responses in brain death.

Auditory brain-stem responses were measured by far-field recording techniques in 27 patients fulfilling the criteria of brain death. The responses were either absent or consisted of the presence of just the initial component (Wave I). Wave I, when present, was of normal amplitude but prolonged in latency. Four patients were followed over several days from a state of coma with evidence of preserved brain-stem and cerebral functions to a clinical state compatible with brain death. Auditory brain-stem responses were initially intact and then showed a decrease in amplitude and a prolongation of latency of the later components until finally Wave I was alone. Auditory brain-stem responses are an objective measure of one of the sensory pathways traversing the brain-stem and can be used to evaluate the functional states of the brain-stem in patients in whom the question of brain death has been raised.

Adult↗
PubMed1976

Brain death.

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Brain Death↗
PubMed1978

Pulsatile cerebral echo in diagnosis of brain death.

Conclusive diagnosis of brain death can be made by the demonstration of prolonged cessation of cerebral blood flow. This report describes a simple method to determine the presence or absence of the blood flow in the brain by recording the pulsatile midline echo on one channel of the electroencephalogram (EEG) or on any four-channel monitoring system in the intensive care unit. A firm transducer holder has been developed to eliminate artifacts caused by transducer motion, The pulsations of the midline echo are assumed to be the result of displacement of the midline structures by the arterial injection of each cardiac systole. Thus, the absence of these midline pulsatile echoes correlates with the absence of cerebral blood flow and, if the absence persists over 30 minutes in the presence of normal blood pressure, then the result is brain death. Twenty-eight cases of clinical brain death with electrocerebral silence of EEG and 18 obtained patients with various types of cerebral pathology were examined by the echo-pulsation technique. Twenty-six of the 28 cases showed no pulsation of the midline echo. The validity of the technique was documented in four cases by four-vessel cerebral angiogram.

Adolescent↗
PubMed1992

[Changes of pupil size in brain death patients].

The representative criteria of brain death in Japan is Takeuchi Criteria (Koseisho Criteria), which is the definition of irreversible loss of brain function (functional brain death). The 3rd item of that criteria is "fixed pupil" and pupil size more than 4 mm. The 4th item is loss of the brain nerve reflexes including the light reflex. Three cases of brain death by whole brain destruction (organic brain death) who showed slow changes of pupil size were reported. Except fixed pupil, one case fulfilled Takeuchi Criteria. Other two cases fulfilled all items of Takeuchi Criteria, showing the same pupil size accidentally at the first and the second judgements. But, they changed their pupil size slowly and continuously after the examinations, showing tendencies toward mydriasis and/or miosis, repeatedly. They never decreased their pupil size less than 4 mm. The changes of pupil size were so slow that we could recognize them only after several hours or several days, and they were quite different from the light reflex. They did not receive any influences from turnover of day and night, darkness of the room, dopamine, etc. For the changes of pupil size were observed in the cases of organic brain death, it was elucidated that they were not due to the brain nerve activity. Then, it was considered that the changes of pupil size in the cases of functional brain death should be the same phenomena, because brain nerve function was lost.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1979

Diagnosis and management of brain death.

Finland was the first country in which brain death was legally accepted. Since 1975, 37 cases of brain death had been recorded in a university hospital in Finland, and these were reviewed. The cause for brain death was intracranial bleeding in 32 cases, other cerebrovascular disorder in two, and intracranial neoplasm in three. In 21 brain death was diagnosed clinically. In 16 cases confirmatory investigations (electroencephalography, cerebral angiography) were needed. After brain death had been established artificial support was withdrawn in 15 patients and organ transplantation was carried out in 10. In 12 patients, however, diagnosis of brain death did not influence management, though the heart stopped beating on average 25 hours after diagnosis. The Finnish criteria for brain death seem to be reliable and suitable for routine use.

Adolescent↗
PubMed1975

Criteria of brain death: review and comparison.

The concept of brain death has become important in law and medicine, replacing in some instances the concept of circulatory arrest as a definition of death. Yet, brain death has not been established as a clear clinical or pathologic entity, a point brought out here by comparison of criteria for identification. The need for more research is evident.

Angiography↗