On patient evaluation, a pure motor deficit (sensation intact) alongside a viral prodrome is potential evidence of paralytic poliomyelitis. Clinically, the prodrome may consist of headaches, myalgias, fatigue, nausea, neck stiffness, or pharyngitis. Up to 95% of poliovirus infections present as this constellation of symptoms and remain non-paralytic. In infections that progress into the spinal cord, severe muscle spasm with myalgias typically present before an asymmetrical flaccid paralysis. The paralysis tends to have a lower limb predominance. Acute flaccid myelitis (AFM) with viral prodrome can also be caused by other viral infections (see differential diagnosis). It is important to note that most other enterovirus-related AFMs have an upper extremity predilection.[10]

Poliomyelitis can present in stages, such as the acute stage, recovery stage, and residual-paralysis stage. The acute stage is mainly comprised of features, such as fever, neck stiffness, profound muscular weakness, paraparesis, and autonomic dysfunction. In the convalescent stage or the recovery stage, the acute features disappear and the recovery of paralyzed muscles begins. This stage can last up to two years. In the last stage, the patient is left with residual paralysis, imbalance of muscle power, and poor posture.

Providers should have a high suspicion of viral meningitis when acute flaccid paralysis is present. Testing should include blood, CSF, respiratory, stool tests, EMG, and brain/spinal cord MRI to rule out other pathologies. Regarding Post-Polio Syndrome, there are no definitive biomarkers widely accepted, thus diagnosis is made by exclusion. There is currently early research of potential biomarkers of PPS in the CSF using PCR.[12]

Supportive care is the mainstay of treatment since there are no approved antiviral medications for poliomyelitis. In patients affected by paralytic polio, most do not regain full strength. The more severe the acute disease is, the greater the likelihood of residual deficits and the development of PPS in the future.[13]

Polio immunity is likely accomplished with the administration of inactivated polio vaccine (IPV) or live-attenuated oral polio vaccine (OPV, Sabin). In developing countries, the OPV is still used primarily because of cost. However, due to the increased possibility of Vaccine-Associated Paralytic Poliovirus (VAPP) with its use, IPV is preferred in most vaccination schedules. The OPV formulation is changing to remove type 2 to reduce the chance of strain mutations, as type 2 is the most common strain of VAPP. Type 2 is being phased out because its wild type has been eradicated as of 1999, yet it continues to cause outbreaks in countries previously completely free of polio.[5] In the United States, IPV is the only vaccine available. Children typically receive 4 doses of IPV at 2 and 4 months, between 6-18 months, and then a booster between 4-6 years of age. This vaccine schedule confers greater than 95% efficacy.[14]

The release of joint contractures is also an important management step. Many surgical interventions can be taken into account in order to reestablish balance in the muscles around the joint to prevent deformities. The aim of surgical management is to get the patient walking and to correct factors that will lead to deformity with age.

In the acute stage, treatment involves general supportive measures for fever and irritation, prevention of respiratory tract infections, and management of any respiratory paralysis. The paralyzed legs are supported by splints in order to relieve pain and spasm. It also plays an imperative role in the prevention of the development of deformities.

In the convalescent stage, the goal should be to achieve an acceptable physical status for the patients in order for them to be integrated into their communities. Nonfatiguing exercise programs are the most appropriate to deal with muscle overuse weakness.

Orthoses are helpful in the conservative and definitive treatment of many deformities, and they are available for all parts of the body.

Other enteroviruses can cause acute flaccid paralysis including enterovirus A71, D68, and coxsackievirus A.[3] Other viruses that may present similarly are West Nile, Herpes Zoster, Japanese Encephalitis, and Rabies. Syndromes such as Guillain-Barré should also be ruled out.[15][16] 

Non-infectious considerations include spinal cord infarctions, acquired axonal neuropathies, myasthenia gravis, Lambert-Eaton myasthenic syndrome, or rhabdomyolysis. Clinical clues such as injury to an affected limb compared to prodromal illness will help to differentiate between diagnoses.

The presentation of polio is highly variable, ranging from viral symptoms without paralysis, to quadriplegia, and even respiratory failure. Polio patients who present with only viral prodromes are likely to see complete resolution of symptoms. For those that experience acute paralysis, the degree of paralysis often remains static. Approximately 30% to 40% of polio patients will develop post-polio syndrome decades after the primary infection. This progression is multifactorial and depends on factors like severity of acute paralysis, age of onset, and even socioeconomic status.[13][17][18]

The greatest complications of polio infection include paralysis with bulbar involvement, fatal respiratory, cardiovascular collapse, and PPS. PPS is characterized by new-onset or progressive muscle weakness in a patient previously diagnosed with poliomyelitis.[13][17] Conservative estimates of up to 30-40% of the 15-20 million known polio survivors worldwide develop some form of PPS. The classic symptom is new or progressive muscle weakness decades after the acute infection. Other symptoms include myalgias, respiratory distress, joint pain, atrophy, dysphagia, and generalized fatigue.[19] The exact pathophysiology of PPS is unknown. It is believed to be a result of the overuse of remaining motor units, inflammatory changes in CNS, or deteriorating neuromuscular junctions.[20] Complications of this syndrome include respiratory failure, fractures, or failure to thrive.

With 60-80% of patients with a past diagnosis of polio reporting at least 1 fall in the past year, rehabilitation and a strong interdisciplinary team are integral.[18] Tailored physical therapy, aquatic therapy, endurance training, and pain control are priorities of PPS treatment. Fitted orthoses can mitigate gait disturbances. Potential orthopedic surgery may be warranted to correct deformities and muscle imbalances.[20] Tricyclic antidepressants are effective against fatigue associated with PPS. There is high variability in the PPS presentation, and each must be carefully considered when beginning treatment plans.

Patients must be educated on how to avoid transmission with proper hygiene and prevention through vaccination efforts. As more communities worldwide oppose vaccinations, informing the public on the potentially deadly and disabling side effects of not receiving the polio vaccine can make an impact. The Global Polio Eradication Initiative partners with the World Health Organization, US Centers for Disease Control, Rotary International, United Nations Children’s Fund, and the Bill & Melinda Gates Foundation to work for a polio-free world. They have laid out a Polio Endgame Strategy with the following key components:

• Routine immunization
  • Goal of >80% vaccination of all children in the first year of life
  • At least three doses of OPV (or IPV per current CDC recommendations) as part of the national immunization schedule
• Supplementary immunization
  • Mass immunization campaigns are known as National Immunization Days
  • 2 rounds, 1 month apart from each other
  • Immunize all children under 5 regardless of immunization status with two doses of OPV
• Surveillance
  • Finding all cases of children with acute flaccid paralysis
  • Stool sample analysis transport
  • Isolating the virus in laboratories
  • Mapping the virus/tracking outbreaks
• Targeted “mop-up” campaigns
  • Door-to-door campaigns in targeted areas of known polio infections or suspected areas.

With an effective vaccine schedule in place, poliomyelitis is often a forgotten-about disease, but we must recognize that polio is still endemic in Pakistan and Afghanistan.[6] With the growing number of communities against vaccinations in developed countries, there is still a great deal of patient education to complete. Furthermore, the recognition and treatment of Post-Polio syndrome will need further discussion with improved testing capabilities in the future.