Related Experiment Video
Updated: Feb 12, 2026
08:39
Establishment of Deep Hypothermic Circulatory Arrest in Rats
Published on: December 16, 2022
2.8K
Systodiastolic Separation Expresses Cerebral Circulatory Arrest?
A Cacciatori1, M Godino1, R Mizraji1
1National Institute of Donations and Transplants, Montevideo, Uruguay.
Transplantation Proceedings
|March 28, 2018
Summary
Systodiastolic separation on transcranial Doppler (TCD) may precede cerebral circulatory arrest (CCA). This pattern is not definitively indicative of brain death (BD) and requires careful clinical correlation to avoid misdiagnosis.
Area of Science:
- Neurocritical Care
- Cerebrovascular Diagnostics
- Neurology
Background:
- Transcranial Doppler (TCD) is used in neurocritical care to assess cerebral blood flow.
- Systodiastolic separation in TCD waveforms can occur before complete cessation of cerebral circulation.
- This specific TCD pattern may cause diagnostic uncertainty regarding brain death (BD).
Purpose of the Study:
- To investigate the diagnostic significance of systodiastolic separation in TCD.
- To determine the correlation between this TCD pattern and the diagnosis of brain death (BD).
- To evaluate the clinical implications of systodiastolic separation in neurocritical patients.
Main Methods:
- Retrospective analysis of 266 TCD studies in 188 neurocritical patients over 9 years.
- Identification of cases exhibiting systodiastolic separation.
- Correlation of TCD findings with clinical neurological examinations and outcomes, including cerebral circulatory arrest (CCA) and brain death (BD).
Main Results:
- Of 266 studies, 88 (77%) showed cerebral circulatory arrest (CCA) associated with brain death (BD).
- Nine studies (5%) presented the systodiastolic separation pattern.
- In the systodiastolic separation group, only 3 patients ultimately progressed to CCA; one retained cough reflex and spontaneous breathing, and five did not reach CCA.
Conclusions:
- Systodiastolic separation on TCD is not a definitive indicator of brain death (BD).
- The presence of minimal persistent neurological signs can exclude a direct correlation with BD diagnosis.
- Careful clinical assessment is crucial when interpreting TCD findings of systodiastolic separation to avoid diagnostic errors.
Related Concept Videos
02:03Anatomy of the Circulatory System
98.4K
The human circulatory system consists of blood, blood vessels that carry blood away from the heart, around the body, and back to the heart, and the heart itself, which acts as a central pump. The systemic circuit supplies blood to the whole body, the coronary circuit supplies blood to the heart, and the pulmonary circuit supplies blood flow between the heart and lungs.
98.4K
01:24Blood Pressure Imbalances and Circulatory Shock
1.7K
Disorders affecting blood volume, vascular tone, or vascular function can disrupt vascular homeostasis, including conditions like hypertension, hemorrhage, and shock.
Blood Pressure: Hypertension and Hypotension
Normal blood pressure is 120/80 mm Hg. Elevated blood pressure is 120-129/under 80 mm Hg. Hypertension, warranting treatment at 130/80 mm Hg, is often asymptomatic and can lead to severe cardiovascular events, aneurysms, peripheral arterial disease, chronic renal disease, or cardiac...
Blood Pressure: Hypertension and Hypotension
Normal blood pressure is 120/80 mm Hg. Elevated blood pressure is 120-129/under 80 mm Hg. Hypertension, warranting treatment at 130/80 mm Hg, is often asymptomatic and can lead to severe cardiovascular events, aneurysms, peripheral arterial disease, chronic renal disease, or cardiac...
1.7K
02:17Separation of Sister Chromatids
4.5K
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
4.5K
01:42What is Gene Expression?
197.1K
Overview
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
197.1K
01:05Cerebral Hemispheres
2.5K
The human brain, a complex organ, is functionally divided into two cerebral hemispheres—left and right. These hemispheres are interconnected by a structure of paramount importance, the corpus callosum. This substantial bundle of neural fibers is not just a bridge between the hemispheres but a crucial element for the brain's comprehensive functioning. It enables efficient communication between the two hemispheres, allowing each side of the brain to control and receive sensory and motor...
2.5K
01:20Separable Differential Equations
109
A separable differential equation is a type of first-order differential equation where the derivative dy/dx can be expressed as a product of two functions: one that depends only on x and another that depends only on y. This allows for the rearrangement of the equation so that all terms involving y are on one side, and all terms involving x are on the other. This process, known as the separation of variables, simplifies the process of solving the equation by enabling the integration of both...
109