Diaschisis: The Disconnection of Neural Networks
Diaschisis, a term coined by German neurologist Kurt Goldstein, is a phenomenon characterized by the loss of function in a remote area of the brain caused by a lesion or injury to another region. It is believed to be a result of a disconnection of neural networks associated with the affected area (Gonzalez-Lara & Yuede, 2008). Diaschisis has been studied extensively in humans and animals and can be observed in cases of stroke, head injury, and tumor infiltration.
The underlying mechanism of diaschisis is still largely unknown, although several theories have been proposed. One theory suggests that diaschisis occurs when the primary lesion or injury causes a disruption of the normal neural network connections, leading to a decrease in the flow of excitatory signals to the remote area (Gonzalez-Lara & Yuede, 2008). This disruption in the flow of signals is thought to lead to a decrease in neural activity and the associated decrease in function.
Another theory suggests that diaschisis is caused by a decrease in the release of neuromodulators and neurotransmitters. It is believed that a primary lesion or injury can lead to a decrease in the release of these chemicals, which can lead to a decrease in the flow of excitatory signals to the remote area (Gonzalez-Lara & Yuede, 2008). This decrease in the flow of signals is thought to cause a decrease in neural activity and the associated decrease in function.
In addition to theories of how diaschisis is caused, several methods have been developed to measure its effects. For example, functional magnetic resonance imaging (fMRI) can be used to measure changes in brain activity during diaschisis (Gonzalez-Lara & Yuede, 2008). Additionally, positron emission tomography (PET) can be used to measure changes in the levels of neurotransmitters and neuromodulators.
Diaschisis is an important phenomenon to understand as it can have a significant impact on the functioning of the brain. A better understanding of the underlying mechanisms of diaschisis can help to develop better treatments for those suffering from stroke, head injury, and tumor infiltration.
References
Gonzalez-Lara, L., & Yuede, C. (2008). Diaschisis: From Pathophysiological to Clinical Concepts. Current Neurology and Neuroscience Reports, 8(2), 139-145. doi:10.1007/s11910-008-0014-9