Diagnosis is based on physical and neurological examination findings, duration of unconsciousness (usually less than 30 minutes) and post-traumatic amnesia (PTA; usually less than 24 hours), and the Glasgow Coma Scale (people with mTBI have scores of 13 to 15). A CT scan or MRI is not required to diagnose concussion. Neuropsychological tests such as the SCAT5/child SCAT5 may be suggested measure cognitive function. Such tests may be administered hours, days, or weeks after the injury, or at different times to demonstrate any trend. Some athletes are also being tested pre-season (pre-season baseline testing) to provide a baseline for comparison in the event of an injury, though this may not reduce risk or affect return to play and baseline testing is not required or suggested for most children and adults.If the Glasgow coma scale is less than 15 at two hours or less than 14 at any time, a CT is recommended. In addition, a CT scan is more likely to be performed if observation after discharge is not assured or intoxication is present, there is suspected increased risk for bleeding, age greater than 60, or less than 16. Most concussions, without complication, cannot be detected with MRI or CT scans. However, changes have been reported on MRI and SPECT imaging in those with concussion and normal CT scans, and post-concussion syndrome may be associated with abnormalities visible on SPECT and PET scans. Mild head injury may or may not produce abnormal EEG readings.
Familial exudative vitreoretinopathy (FEVR, pronounced as fever) is a genetic disorder affecting the growth and development of blood vessels in the retina of the eye. This disease can lead to visual impairment and sometimes complete blindness in one or both eyes. FEVR is characterized by incomplete vascularization of the peripheral retina. This can lead to the growth of new blood vessels which are prone to leakage and hemorrhage and can cause retinal folds, tears, and detachments. Treatment involves laser photocoagulation of the avascular portions of the retina to reduce new blood vessel growth and risk of complications including leakage of retinal blood vessels and retinal detachments. Information
Pathophysiology
FEVR is caused by genetic defects involving the regulation of blood vessel growth in developing eyes. As a result, there is poor blood vessel growth to the periphery of the retina. The lack of blood supply to the peripheral retina triggers the release of molecules that stimulate blood vessel growth, such as vascular endothelial growth factor (VEGF). However, this new blood vessel growth, also known as neovascularization, can lead to further complications such as the leakage and hemorrhage of retinal blood vessels, retinal tears, and detachments.Genetics
There have been several gene mutations associated with FEVR. These genes code for proteins involved in the WNT signaling pathway, which is involved in the development of the human eye and regulation of blood vessel growth. Depending on the genes involved, FEVR can follow an autosomal dominant, autosomal recessive, or X-linked inheritance pattern. There is varying penetrance and expressivity depending on the genes involved.