Whooping cough eight weeks, or sometimes longer. A gradual transition then occurs to the convalescent stage, which usually lasts one to four weeks. This stage is marked by a decrease in paroxysms of coughing, although paroxysms may occur with subsequent respiratory infection for many months after the onset of pertussis. The time between exposure and the development of symptoms is on average 7–14 days (range 6–20 days), rarely as long as 42 days. Pertussis is caused by the bacterium "Bordetella pertussis". It is an airborne disease (through droplets) that spreads easily through the coughs and sneezes of an infected person. Uncertainties have
Alexander disease the ability to talk. It also causes an overload of long-chain fatty acids in the brain, which destroy the myelin sheath. The cause of Alexander disease is a mutation in the gene encoding GFAP. A CT scan shows: Detecting the signs of Alexander disease is possible with magnetic resonance imaging (MRI), which looks for specific changes in the brain that may be tell-tale signs for the disease. It is even possible to detect adult-onset Alexander disease with MRI. Alexander disease may also be revealed by genetic testing for its known cause. A rough diagnosis may also be made through revealing