Diaschisis is a sudden loss of function in a portion of the brain connected to but at a distance of a damaged area. The site of the originally damaged area and of the diaschisis are connected to each other by neurons. The loss of the damaged structure disrupts the function of the remaining intact systems and causes a physiological imbalance. The injury is produced by an acute focal disturbance in an area of the brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

. Some function may be restored with gradual readjustment of the intact but suppressed areas.

The term diaschisis was coined by von Monakow in 1914. Currently the term diaschisis is used to describe a depression of regional neuronal metabolism

Metabolism

Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

 and cerebral blood flow

Cerebral blood flow

Cerebral blood flow, or CBF, is the blood supply to the brain in a given time. In an adult, CBF is typically 750 millitres per minute or 15% of the cardiac output. This equates to 50 to 54 millilitres of blood per 100 grams of brain tissue per minute. CBF is tightly regulated to meet the brain's...

 caused by dysfunction

Dysfunction

Dysfunction can refer to:* Abnormality * Dysfunctional family* Sexual dysfunction* Dysfunction , an album by the rock band Staind...

 in an anatomically separate but functionally related neuronal region.

It is important to note that diaschisis is a dysfunction of tissue that is not damaged but for which the blood supply has been altered because of interruption of "up stream". Diaschisis can be related to traumatic brain injury

Traumatic brain injury

Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...

 or stroke

Stroke

A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

. The relief of diaschisis can sometimes be achieved through intervention and the brain's natural neuroplasticity

Neuroplasticity

Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment. Plasticity occurs on a variety of levels, ranging from cellular changes involved in...

.