Post-concussion syndrome
About 10% of people with PCS develop sensitivity to light or noise, about 5% experience a decreased sense of taste or smell, and about 14% report blurred vision. People may also have double vision or ringing in the ears, also called tinnitus. PCS may cause insomnia, fatigue, or other problems with sleep.
Posterior cord syndrome
PCS originates from an infarct in the posterior spinal artery and is caused by lesions on the posterior portion of the spinal cord, specifically the posterior column, posterior horn, and posterolateral region of the lateral column. These lesions can be caused by trauma to the neck, occlusion of the spinal artery, tumors, disc compression, vitamin B12 deficiency, syphilis, or multiple sclerosis. Despite these numerous pathological pathways, the result is an interruption in transmission of sensory information and motor commands from the brain to the periphery.