Ulegyria is a diagnosis used to describe a specific type of cortical scarring in the deep regions of the sulcus that leads to distortion of the gyri. Ulegyria is identified by its characteristic "mushroom-shaped" gyri, in which scarring causes shrinkage and atrophy in the deep sulcal regions while the surface gyri are spared. This condition is most often caused by hypoxic-ischemic brain injury in the perinatal period. The effects of ulegyria can range in severity, although it is most commonly associated with cerebral palsy, mental retardation and epilepsy. N.C. Bresler was the first to view ulegyria in 1899 and described this abnormal morphology in the brain as “mushroom-gyri." Although ulegyria was first identified in 1899, there is still limited information known or reported about the condition. Anatomy
The physical features of ulegyria consist of small radial scars which occupy the cortical sulci. Overall, the physical structure of affected areas in the brain is described as a “mushroom”-like shape in which the gyri are unusually large and the sulci become wider deeper in the cortex. N.C. Bresler, the first person to view a brain with ulegyria in 1899, coined the phrase mushroom gyri. He also named the disorder, basing it off the Latin root ule, meaning scar. This mushroom-like structure is the result of the lower parts of the ulegyria-affected area being more prone to deterioration, while the upper gyri are usually spared. However, the entire affected area shrinks and presents brown coloration as a result of ulegyria.
Ischemia causes anoxic cell depolarizations and it is this increase in membrane potential at the presynaptic cell that triggers the release of glutamate, an excitatory neurotransmitter.Glucose deprivation in the brain for any amount of time has the potential to pose serious consequences, and the amount of time the brain spends under these anoxic conditions is directly related to accumulation of irreversible damage to protein biosynthesis pathways. Protein synthesis all over the body is severely inhibited and essentially comes to a standstill while the brain is suffering from acute oxygen deprivation. Once oxygen sufficiently saturates the tissues again, protein biosynthesis returns to normal in non-vulnerable areas but remains at below normal levels in other areas. Insufficient protein synthesis in the brain is especially troubling in the fetal brain given the amount of growth and development that normally occurs. Areas particularly vulnerable to the damaging effects of hypoxic episodes include: the superior brainstem, the cerebellum, white matter and subcortical structures supplied by the branches of deep and superficial penetrating blood vessels. Vulnerable areas where protein synthesis is interrupted usually indicate impending cell death in neurons. When oxygen levels return, oxygen radicals, nitric oxide and an imbalance of neurotransmitters cause further damage and lead to cellular death through apoptosis. Neuron cell death is responsible for gliosis and results in the mushroom appearance of areas and is characteristic of ulegyria. Cerebral hemorrhage
A cerebral hemorrhage is the result of immature blood vessels of a brain lesion bursting.