Introduction – Acute Flaccid Myelitis
Acute flaccid myelitis (AFM) is a rare disease that affects the spinal cord, the part of the nervous system that carries messages to and from the brain. Symptoms of AFM include sudden (acute) weakness in the arm(s) or leg(s), along with loss of muscle tone and decreased or absent reflexes. Some people with AFM report pain. In some cases, AFM can affect the nerves controlling the head and neck, causing facial weakness, drooping of the eyelids, and difficulty swallowing, speaking, or moving the eyes. The most serious complication of AFM is a respiratory failure if the muscles involved with breathing become weakened. Most cases of AFM have been in children, but it can develop in adults.
What causes AFM?
- There is a lot still unknown about the causes of AFM, but the CDC believes certain viruses play a role in what many refer to as a “mystery illness.”
- In 2014, there was a rise in AFM cases during an enterovirus D68 (EV-D68) outbreak. However, not all AFM patients had the enterovirus virus.
- Other viruses, environmental toxins and genetic disorders are also potential causes of AFM.
- Enteroviruses and rhinoviruses are also among the identified causes in many 2018 AFM cases.
- Sudden onset of arm or leg weakness and loss of muscle tone and reflexes is the most common symptom.
- Seek medical care right away if you or your child develops any of these symptoms.
Most people will have a sudden onset of:
- Arm or leg weakness
- Loss of muscle tone and reflexes
Some people will also have:
- Facial droop or weakness
- Difficulty moving eyes
- Drooping eyelids
- Difficulty swallowing
- Slurred speech
- Pain in arms or legs
In rare cases, people may also:
- Have numbness or tingling
- Be unable to pass urine (pee)
The most severe symptoms of AFM are:
- Respiratory failure: This happens when the muscles involved with breathing become weak and can require a ventilator (a machine to help them breathe).
- Serious neurologic complications: In very rare cases, it is possible that the process in the body that triggers AFM may also trigger other serious neurologic complications that could lead to death.
Complications of AFM
- Trouble breathing
- Difficulty swallowing (dysphagia)
- Talking (dysphonia)
- AFM patients may find difficult of doing ordinary tasks such as dressing, bathing, and grooming
- Urinary retention
- Difficulty with the evacuation of stool
- Sexual dysfunction
- Respiratory Dysfunction
- Skin breakdown occurs if the skin is exposed to pressure for a significant amount of time, without sensation or the strength to shift position as necessary.
- Pain is common following AFM.
- Autonomic Dysreflexia
Diagnosis of acute flaccid myelitis
- Acute flaccid myelitis is diagnosed based upon clinical exam, magnetic resonance imaging (MRI) of the spinal cord, and analysis of cerebrospinal fluid (CSF) (usually with increased white blood cells or pleocytosis).
- On MRI of the spinal cord, AFM lesions are longitudinal throughout the grey matter (the anterior horn cells).
- Sometimes imaging may appear normal early in the disease, but repeat imaging shows the lesions. In some situations, electrophysiological studies of the nerves and muscle (called nerve conduction and electromyogram [NCS/EMG]) may help to determine if there is an injury to the lower motor neuron. Testing may also include blood draws, respiratory tract samples or collection of other bodily fluids to determine if a viral or infectious cause is present.
Treatment of acute flaccid myelitis
There’s no cure for either polio or AFM, but some things can help with symptoms. Children with either polio or AFM may need:
- Pain relievers like ibuprofen to ease pain and bring down fever
- Fluids to keep them from being dehydrated
- A machine called a ventilator to help them breathe
- Physical therapy to make weak muscles stronger
- Occupational therapy to help with everyday activities like dressing and eating
Rehabilitation for acute flaccid myelitis
Recovery from AFM is a process. There is no curative treatment found to date. Recovery is based on treating symptoms. A physician that specializes in physical medicine and rehabilitation (called a physiatrist), a neurologist, a pediatrician or a combination of specialists will coordinate medical needs. A urologist might also be consulted for bladder management. There might be a combination of specialists who will work together to coordinate care.
Rehabilitation will include physical and occupational therapy to provide input to those nerves and muscles that are underpowered. Physical therapy directs their efforts towards gross movement such as sitting, standing and walking. Occupational therapy focuses on fine movement of hands and fingers, as well as activities of daily living, dressing, bathing, and feeding. Avoiding further complications is also in their plan. They advance therapy as the individual improves. Respiratory therapy will assist with ventilation needs (both noninvasive and with mechanical ventilation). They can provide direction for increased ventilation as well as weaning when no longer needed.
Speech therapy will be involved if there are oral motor deficits. This will help with controlling swallowing and avoiding aspiration or swallowing of fluid and foods into the lungs. The Speech and Language Pathologist will assist with speaking as needed.
Registered nurses will carry out the therapist’s recommendations throughout the day. They will plan bladder, bowel and skincare management as well as helping transition to home.
The hospital case manager will be in contact with your insurance case manager to coordinate needed care. Once home, you will work directly with the insurance case manager.
All these professionals will work together to coordinate the needed care and to encourage recovery. A few individuals will have recovery, others might not see much improvement. There is no indication of how much people will recover.
How can you prevent acute flaccid myelitis (AFM)?
To prevent AFM, doctors recommend that you:
- Get your vaccines on schedule, especially the polio vaccine.
- Try to stay away from mosquitoes that can transmit viruses by not going outside when they are biting (dusk and dawn). Use products that repel mosquitoes, and do not allow water to collect near your home.
- Follow good hand washing practices—using soap and water and washing frequently—is good advice to prevent illness in general. Also, wash your hands before and after eating; after using the bathroom or touching an animal; before and after taking care of someone who is sick or has a cut.
- Avoid being around people who are sick if you can.
- Do not share eating utensils or cups, straws, or cigarettes.
- Use disinfectant to clean hard surfaces.