Acute Flaccid Myelitis: Causes & Treatment

Acute Flaccid Myelitis (AFM) is a rare but serious neurological condition that primarily affects the spinal cord, leading to sudden onset muscle weakness or paralysis.

While AFM is relatively uncommon, its significance lies in its potential to cause severe and sometimes permanent disability, particularly in children. The exact prevalence of AFM is not well-defined, but outbreaks have been reported sporadically worldwide.

The impact of AFM on health is profound, as it can impair essential functions such as mobility, muscle strength, and coordination.

In the short term, untreated AFM can result in respiratory failure and the need for ventilatory support, while in the long term, it may lead to muscle atrophy, joint contractures, and chronic pain.

One of the challenges with AFM is its asymptomatic nature in the early stages, making early detection through regular screenings crucial for timely intervention and management.

Causes of Acute Flaccid Myelitis

The causes of AFM can be multifactorial, with several primary and secondary factors contributing to its development.

Primary Causes

• Viral Infections: Viruses such as enteroviruses, particularly enterovirus D68, have been implicated as primary triggers for AFM. These viruses can invade the nervous system, leading to inflammation and damage to the spinal cord.
• Autoimmune Response: In some cases, AFM is believed to result from an abnormal immune response where the body's immune system mistakenly attacks healthy nerve cells in the spinal cord, causing paralysis.
• Environmental Factors: Environmental toxins or pollutants may play a role in triggering AFM by disrupting normal neurological functions.
• Genetic Predisposition: Genetic factors may contribute to an individual's susceptibility to developing AFM, although the exact genetic mechanisms are still under investigation.

Secondary risk factors or lifestyle contributors that may increase the risk of AFM include:

Secondary Causes

• Age: Children are more susceptible to AFM than adults, with most cases reported in individuals under 18 years old.
• Seasonal Variation: AFM cases tend to peak in late summer and fall, coinciding with the circulation of certain viruses.
• Poor Hygiene Practices: Inadequate handwashing and exposure to contaminated surfaces may increase the risk of viral infections that can lead to AFM.

Symptoms of Acute Flaccid Myelitis

The symptoms of AFM can vary in severity and presentation, with early-stage symptoms often mimicking common viral illnesses and advanced-stage symptoms indicating more significant neurological involvement.

Early Symptoms:

• Muscle Weakness: Early signs of AFM may include sudden onset weakness in one or more limbs, affecting a person's ability to perform daily activities such as walking or grasping objects.
• Fatigue: Fatigue and decreased energy levels may accompany muscle weakness, leading to increased difficulty in completing usual tasks.

Advanced Symptoms:

• Paralysis: Progressive muscle weakness may evolve into complete paralysis of affected limbs or even respiratory muscles, requiring immediate medical attention and supportive care.
• Pain: Neuropathic pain or muscle cramps can develop in advanced stages of AFM, contributing to physical discomfort and emotional distress.

Diagnosis of Acute Flaccid Myelitis

Diagnosing AFM involves a comprehensive evaluation that includes clinical history, physical examination, and specialized tests to confirm spinal cord involvement and rule out other conditions.

• MRI of the Spine: Magnetic resonance imaging (MRI) of the spinal cord is a key diagnostic tool that can reveal characteristic changes indicative of inflammation and damage in AFM.
• Cerebrospinal Fluid Analysis: Analysis of cerebrospinal fluid obtained via a lumbar puncture can help identify viral or inflammatory markers associated with AFM.
• Electromyography (EMG): EMG is used to assess the electrical activity of muscles and nerves, aiding in the localization of nerve damage in AFM.
• Nerve Conduction Studies: These tests evaluate how well electrical signals travel along nerves, providing additional information on nerve function in AFM.

Treatment Options for Acute Flaccid Myelitis

Treatment for AFM focuses on managing symptoms, providing supportive care, and addressing potential complications to optimize recovery and quality of life.

• Medications: Anti-inflammatory medications and immunomodulatory agents may be prescribed to reduce spinal cord inflammation and modulate the immune response in AFM.
• Physical Therapy: Rehabilitation programs tailored to individual needs can help improve muscle strength, mobility, and function in patients with AFM.
• Respiratory Support: Patients with severe respiratory involvement may require mechanical ventilation to maintain adequate oxygenation and prevent respiratory failure.
• Psychological Support: Emotional support and counseling are essential for individuals and families coping with the physical and emotional challenges of AFM.

By understanding the causes, symptoms, diagnosis, and treatment options for AFM, healthcare providers can better assist in early detection, prompt intervention, and comprehensive management of this complex neurological condition.