Bulbar poliomyelitis is a specific type of an extremely rare viral paralytic disease in which the typical findings of acute flaccid paralysis are accompanied by bulbar symptoms - dysphagia, dysphonia, nasal regurgitation, as well as vascular and respiratory impairment in severe cases. The diagnosis rests on clinical criteria, microbiological studies that identify the poliovirus in samples (either polymerase chain reaction or antibody detection), but most importantly, confirming whether patients were vaccinated for polio.
Through widespread vaccination, the global effort to eradicate polio has led to a marked decrease in the number of individuals suffering from poliomyelitis, a highly contagious infection caused by three distinct poliovirus serotypes, although serotype 1 is responsible for the majority of human cases     . Poliovirus belongs to the group of enteroviruses, and as a result, its mode of transmission involves the human gastrointestinal tract and the fecal-oral route   . Namely, poliomyelitis is established as a disease that solely affects human hosts and the majority of infections end in an asymptomatic fashion   . Once the virus reaches the human gastrointestinal (GI) tract, it is secreted in saliva in the first few days and in feces for a period of a few weeks, during which direct contact with secretions can result in transmission of the infection  . Poliomyelitis, when symptomatic, can present in many forms, including abortive poliomyelitis (a milder type that presents with GI or flu-like symptoms and spontaneously resolves in approximately 7 days), aseptic meningitis (neck stiffness, and weakness in some cases, may accompany constitutional complaints), and paralytic poliomyelitis   . Bulbar poliomyelitis is considered to be one of the most severe and most fatal forms of paralytic poliomyelitis, due to the involvement of the brainstem neurons . In addition to acute flaccid paralysis, bulbar poliomyelitis presents with dysphagia, dysphonia, nasal voice along with nasal regurgitation, as well as respiratory failure, autonomic nervous system dysfunction, and vasomotor disturbances (either hyper or hypotension or even vascular collapse)  . Some authors describe a pure bulbar poliomyelitis without signs of weakness and limb paralysis .
The diagnosis of poliomyelitis is now rare in the developed world and is restricted to poorly sanitized areas that do not conduct standard vaccination protocols for poliovirus  . Countries in which a high risk of an outbreak exists are India, Somalia, Ethiopia, Chad, Congo, Angola and South Sudan, whereas Nigeria, Afghanistan, and Pakistan are considered to be endemic for this virus . For this reason, physicians must include poliomyelitis in the differential diagnosis of acute flaccid paralysis in patients who are from these areas. Apart from assessing information about vaccination, a comprehensive physical examination, especially focusing on neurological evaluation, might provide key findings in order to discriminate bulbar poliomyelitis from other forms of this infection. To solidify the diagnosis, however, microbiological studies need to be conducted. Identification of viral genetic material through a polymerase chain reaction (PCR) test is currently the gold standard of establishing a poliovirus infection    . The stool is the ideal sample from which poliovirus can be detected, but blood and throat swab (only in the first few days of infection), as well as the cerebrospinal fluid (CSF), although rare, might be used  . Alternatively, serological methods that detect antibodies for this virus might also be implemented, as their very high titers appear early in the course of infection and persist throughout life  .