What Is Pediatric Multiple Sclerosis?

Multiple Sclerosis (MS) is usually thought to be a disorder that occurs in adults, and it might be surprising and distressing to learn that children can also be susceptible to this disease. In fact, due to modern technology and research, more children are being diagnosed with MS. Apart from being a rare disorder in children, the symptoms of MS in childhood can be quite similar to other disorders, which can lead to its misdiagnosis. It is often known as pediatric-onset MS (POMS). 

MS is an autoimmune disorder that affects the brain and the spinal cord, collectively known as the central nervous system (CNS). In this disorder, the body's immune system, which usually protects against infections, causes damage to the CNS. It causes the breakdown of a protective barrier surrounding the CNS nerves, called the myelin sheath. 

Epidemiology and Demographics 

It has been shown that out of the total number of patients with MS, at least 5% are children and the incidence of POMS is seen as 3-10% for the under-16 age group and less than 1% for under the age of 10.¹ From this information, it can be seen that POMS is more likely to occur in early adulthood. 

It has also been seen that the female-to-male ratio in early adulthood is 3:1, which shows a female predominance.²

There are different types of MS and in POMS the most common type seen is the relapsing-remitting kind (98%), in which symptoms can come and go.¹ This is a contrast to adults in which the most common type of MS seen is primary progressive, in which the symptoms of MS continue through the disorder. 

Aetiology and Risk Factors 

The exact reasons that cause POMS are not understood well and still need to be researched further. There might be some genetic predisposition or risk of inheritance but these would also need to be triggered by some specific environmental factors to activate MS. Some common environmental triggers are thought to be: 

• Being infected by Epstein-Barr Virus
• Exposure to certain toxins such as cigarette smoke, pesticides
• A low vitamin D level
• Female obesity, especially at the age of 18²

After puberty, there is also an increased incidence of cases being seen in female patients which could suggest a role of sex hormones in the onset of POMS. 

There are also some Human Leukocyte Antigen genes which have been implicated in cases of POMS, such as HLA-DRB1*1501. In addition, POMS is more likely in children who have first-degree relatives with MS. 

However, none of these factors means that the child will get MS and there are still a lot of things which are unknown about the risk factors associated with the development of MS. It is not possible to predict MS or POMS, nor is this disorder contagious. 

Clinical Presentation 

The symptoms which occur in MS are caused by the demyelination of the neurons in the brain and spinal cord. The type of symptoms which occur can vary from person to person and they depend on which part of the CNS has undergone damage. The common symptoms experienced listed below can be similar for both adults and children suffering from MS with a few differences: 

• Visual problems such as blurred or double vision as well as the development of optic neuritis 
• Difficulties concentrating and problems with memory 
• Experiencing depression or anxiety 
• Extreme fatigue, often with tremors and weakness
• Problems with walking and balancing often accompanied by dizziness
• A “pins and needles” type feeling that does not subside, with numbness and/or tingling

These symptoms are not specific for POMS and there are a lot of other disorders that can present with similar symptoms. If your child is experiencing any of them, you should visit a doctor for a proper diagnosis. 

POMS patients usually present with several symptoms occurring at once, and have significant problems with memory and concentrating. In addition, they usually reach a stage of disability in a shorter period than adults with MS but the disease itself is slower in progression than that for adults.³ However, they recover from any relapse quicker than adults do. 

Diagnostic Criteria

Since the symptoms of POMS are so similar to other childhood disorders, your doctor might conduct a series of tests and examinations to properly diagnose the correct condition. It is important to seek an early diagnosis so that you can be guided towards the proper treatment. 

It might start  with your doctor asking you some detailed questions about your symptoms and then conducting a neurological examination to test various parts of your CNS. 

Several other tests might also be conducted such as:

• Several blood tests and urine tests
• Magnetic Resonance Imaging (MRI)
• Lumbar puncture 
• Evoked potential tests

There are certain diagnostic criteria which have been set out for the diagnosis of POMS. The “Mcdonald Criteria” is widely used and it is based on clinical findings, as well as MRI or lumbar puncture findings. This has replaced the previous “Poster Criteria” which is now only used in countries that do not have access to an MRI.⁴

The McDonald criteria aim to identify damage to the CNS. This is evaluated through either clinical evidence of CNS damage, such as the POMS symptoms listed above or conclusive test findings which can be seen through lumbar puncture results or MRI results. 

Two things need to be established to meet McDonald criteria; there needs to be dissemination in both space and time. This means that you would have to have MS attacks or relapses spread out over a period of time, and not all clustered in one time period. This would show dissemination in time. You would also have to show damage to different parts of the CNS which would show dissemination over space. This can be evaluated through clinical examinations or test findings. 

Treatment Approaches

Unfortunately, there is no cure for POMS or MS and treatment aims to prevent relapses and to slow down the progression of the disease. Mainly, Disease Modifying Therapies (DMTs) are used to control the symptoms and relapses. 

For acute attacks, the main form of treatment is intravenous glucocorticoids. For long-term treatments the drugs used are called interferon beta drugs and glatiramer acetate. An oral drug was approved in 2018 for the treatment of POMS in children over 10 years of age. This drug is called Fingolimod and it has proven to be effective in reducing relapses in children.⁵

Other symptoms of POMS can also be treated to provide relief and comfort to the patient. For example, fatigue can be treated with occupational therapy or medication and symptoms such as depression and anxiety can be treated with medication or referring the patient to a psychiatrist. 

Psychosocial Impact and Future Research

POMS is a life-changing disorder and it does require certain lifelong adjustments. Children who are diagnosed with POMS can experience changes in memory, learning and concentration which can affect their school life and lead to feelings of frustration and anxiety. Also, their physical capabilities will be impacted due to fatigue and weakness and again, these can lead to negative feelings and feelings of isolation. The affected child will also require lifelong appointments and follow-up with their medical team which can also be seen as a burden. 

It has been proven that the negative psychosocial impact on patients can worsen their MS symptoms.⁶ Therefore the patient must receive proper counseling, therapy and support in their MS journey. Living a healthy lifestyle is also important and it is encouraged that patients establish a healthy diet, stay hydrated and get plenty of  exercise and sleep. 

There has been a lot of research conducted on adult MS. Due to the similarity of the symptoms of POMS to other childhood disorders, there has been a lot of misdiagnosis and confusion surrounding POMS. It has only recently started to get more diagnosed in children, thanks to modern medicine and now, due to the proper diagnosis, more trials and research are being conducted into POMS. 

Summary 

MS is a chronic demyelinating condition which damages the myelin sheath of nerves. Although POMS is rare, it is a disorder that can impact someone's life. The most common childhood type of POMS is relapsing-remitting and it can take quite a few years to reach the disability stage due to the slow progression of this disease. 

The exact causes are unknown but certain risk factors have been implicated. Diagnosis of POMS is done using the Mcdonald criteria which can help to distinguish it from other similar childhood disorders. There is also no complete cure for POMS but DMTs and symptomatic treatments are the mainstay of this disorder. This treatment aims to prevent relapses and slow progression. It is essential to seek out prompt treatment as an early diagnosis and treatment regime have shown better results. 

A multidisciplinary team approach is best, with lots of support and counselling given to the affected patients. Further research is still needed to develop treatment specifically for children with MS and treatment which can improve quality of life.