Infections are a cause of encephalopathy. Many types of bacteria, viruses, and fungi can cause encephalitis by infection and inflammation of the brain tissue or of the meninges (meningitis) that line the brain and spinal cord.
A value of zero indicates that there is no relationship between the two variables. If the correlation coefficient of two variables is zero, it signifies that there is no linear relationship between the variables. However, this is only for a linear relationship; it is possible that the variables have a strong curvilinear relationship.
A value close to -1 indicates a negative linear correlation; that is, when one variable increases the other decreases. A value close to 0 indicates a non-linear, or random, correlation. The equation for calculating the correlation coefficient is where Xi and Yi are the set of variables, and the sample means.