The return of Polio to the USA? Is paralysis being mis-diagnosed as psychiatric?
This is the first of two posts. The first post provides some essential background, and the second post examines the statistical anomaly that suggests that FND might be over-diagnosed in the US and UK.
1) Functional Neurological Disorder (FND) is a new-ish diagnosis used by doctors to imply that a patient's neurological symptoms are not real. A patient who comes into the doctor's office paralyzed in one leg is told that they are imagining their own paralysis and is given a diagnosis of Functional Neurological Disorder (FND).
2) Poliomyelitis (polio) is a disease defined by specific signs and symptoms, including paralysis. Since this disease is defined by specific signs and symptoms, patients were diagnosed with polio based on these signs and symptoms up until the mid-1990's. In the mid-1990's, diagnoses of polio started to require evidence of specific viruses, known as polioviruses.
3) Polioviruses are considered strongly associated with poliomyelitis (polio) because, in the 1950's, most of the outbreaks of polio were correlated with polioviruses found in sewage, and occasionally in the blood of the outbreak population. However, once a polio patient started showing neurological signs and symptoms, the virus had already moved out of the bloodstream into the nervous system, so diagnosis could not be made based on detection of the poliovirus in the blood. In some polio outbreaks, like the large 1955 outbreak in the USSR, no evidence of polioviruses could be found.
4) In the mid-1990's, the World Health Organization (WHO) started to receive reports of poliomyelitis that could not possibly be linked to any poliovirus. The World Health Organization (WHO) decided to call these reports "Acute Flaccid Paralysis", in order to distinguish them from polio cases that were related to polioviruses. WHO then asked all their member countries to start keeping records on cases of Acute Flaccid Paralysis (AFP), and to provide WHO with yearly reports of the number of cases. For some reason, the WHO requested that countries only report on cases of patients up to the age of 14 years old.
5) Many countries agreed to start reporting childhood Acute Flaccid Paralysis (AFP) cases to the WHO on a yearly basis. Unfortunately, some countries, such as the US, UK, and Germany, refused to provide the requested yearly reports to the WHO.
Here is a graph that shows the reports of childhood AFP that were received by WHO:
 Hyde MD, Byron. The Return of Polio to the USA. 2019 Kindle Edition.