Most patients with a normal immune system will be asymptomatic and will have a normal physical exam. 4 to 8% of patients may develop abortive poliomyelitis, that may only show fever on the physical exam. 1 to 2% of patients will manifest non-paralytic poliomyelitis, that may present with findings of nuchal rigidity, and positive Kernig’s and Brudzinski’s signs. Less than 1% of patients will have paralytic poliomyelitis. This form of the disease may be manifested as: spinal paralytic poliomyelitis or bulbar paralytic paralysis. The spinal form may present with: fever; meningeal signs; weakness of the extremities; and asymmetrical flaccid paralysis, most frequently of the lower limbs. The bulbar form may present with: pharyngeal paralysis, with accumulation of secretions, inability to swallow and sometimes respiratory arrest. When poliencephalitis occurs, seizures and spastic paralysis may be present.

About 95% of patients with an healthy immune system are asymptomatic and have a normal physical examination.^[1]

4 to 8% of poliovirus infection may lead abortive poliomyelitis, a mild symptomatic disease with little findings on physical exam. 2 to 3 days of fever may be the only finding.^[2]

Poliovirus infection may cause non-paralytic (1-2%) or paralytic (<1%) forms of the disease. Physical findings in these forms of the disease may include:

Meningeal signs may be present on physical exam:^[2]

• Nuchal rigidity
• Positive Kernig’s sign
• Positive Brudzinski’s sign

• A fever is often present

• Weakness of the extremities, predominantly of the proximal muscles, is characteristic of this form of the disease. Lower extremities are more often involved.
• Asymmetrical flaccid paralysis, predominantly of the proximal muscles, is characteristic of this form of the disease. Lower extremities are more often involved.

• Meningeal signs may be present on physical exam, such as:^[2]

• Nuchal rigidity
• Kernig’s sign
• Brudzinski’s sign

• Initially hyperactive deep tendon reflexes, that later become absent.
• Common combinations of limb involvement include:

• One lower limb, followed by one upper limb
• Both lower limbs, followed by both upper limbs

• Quadriplegia is a rare finding in infants.

• Pharyngeal paralysis, evidenced by accumulation of secretions is often present in this form of the disease.^[2]
• Inability to swallow^[2]

• In rare severe cases, respiratory centers may be affected, leading to inability to breathe.^[2]

• Seizures are often present
• Spastic paralysis may be present