Posterior cord syndrome (PCS), also known as posterior spinal artery syndrome (PSA), is a type of incomplete spinal cord injury. PCS is the least commonly occurring of the six clinical spinal cord injury syndromes, with an incidence rate of less than 1%. 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. Causes
Trauma to the spinal cord, such as neck hyperflexion injuries, are often the result of car accidents or sports-related injuries. In such injuries, posterior dislocations and extensions occur without the rupture of ligaments. This blunt trauma may be further complicated with subsequent disc compression. In addition to these complications, transient ischemic attacks could occur in the spinal cord during spinal artery occlusion.Common pathological sources of PCS include Friedreichs Ataxia, an autosomal-recessive inherited disease, and tumors such as astrocytoma, ependymoma, meningioma, neurofibroma, sarcoma, and schwannoma. Cobalamin, commonly known as vitamin B12, plays a crucial role in the synthesis and maintenance of myelin in neurons found in the spinal cord.
As a flavouring agent in drinks, quinine is limited to less than 83 parts per million in the United States, and 100 mg⁄l in the European Union. Scientific
Quinine (and quinidine) are used as the chiral moiety for the ligands used in Sharpless asymmetric dihydroxylation as well as for numerous other chiral catalyst backbones. Because of its relatively constant and well-known fluorescence quantum yield, quinine is used in photochemistry as a common fluorescence standard. Contraindications
Because of the narrow difference between its therapeutic and toxic effects, quinine is a common cause of drug-induced disorders, including thrombocytopenia and thrombotic microangiopathy. Even from minor levels occurring in common beverages, quinine can have severe adverse effects involving multiple organ systems, among which are immune system effects and fever, hypotension, hemolytic anemia, acute kidney injury, liver toxicity, and blindness. In people with atrial fibrillation, conduction defects, or heart block, quinine can cause heart arrhythmias, and should be avoided.Quinine can cause hemolysis in G6PD deficiency (an inherited deficiency), but this risk is small and the physician should not hesitate to use quinine in people with G6PD deficiency when there is no alternative. Adverse effects
Quinine can cause unpredictable serious and life-threatening blood and cardiovascular reactions including low platelet count and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP), long QT syndrome and other serious cardiac arrhythmias including torsades de pointes, blackwater fever, disseminated intravascular coagulation, leukopenia, and neutropenia. Some people who have developed TTP due to quinine have gone on to develop kidney failure.