The Brain and Central Nervous System
In order to understand neuroinflammatory disorders, let us first take a look at the Central Nervous System and the Immune System.

Active brain and spinal cord
  • The CNS is the main control centre of your body: it receives, interprets and sends messages so that your body can work properly. It controls how you think, walk, listen to a song and how fast your heart beats.
  • The CNS is made up of the brain and the spinal cord. The brain is divided into several different parts or lobes. Each lobe has a specific role. Inside the CNS are neurons or special nerve cells.
  • Neurons are covered in a special layer called myelin, just like insulating rubber on an electrical wire. Myelin helps nerve signals travel faster.
  • The spinal cord is a long column (about 44 cm long in an adult) of nervous tissue that runs from the base of the skull to the mid-lower back. All nerves to the arms and legs are connected to the spinal cord.
  • The spinal cord is enclosed within the vertebral column and is surrounded by a protective membrane called the meninges. Within the meninges the spinal cord is bathed with a clear fluid called cerebral spinal fluid or CSF.

Active neuron, or nerve cell. Our brain contains 100 billion neurons like this one!

  • The immune system is the body’s way of fighting against infection.
  • The immune system is made up of multiple types of immune cells (E.g., T cells and B cells), lymph glands, bone marrow and the thymus gland.
  • Immune cells remember what infections the body has seen in the past, and are prepared to get rid of these invading infections if they come back.
  • Unfortunately, immune cells can make a mistake and attack a part of the body, (i.e. the brain), thinking it is an unwanted organism or invader.
Neuroinflammatory Disorders

Multiple Sclerosis (MS) is an autoimmune disorder, where the body’s immune system attacks the myelin (protective sheaths that cover nerve fibres) in the brain and spinal cord. This causes problems with communication between the brain and the rest of the body, eventually leading to damage of the nerves themselves. There is currently no cure for MS. However, there are treatments to manage symptoms, prolong the progression of the disease, and to speed up the recovery from an attack.

For more information, visit The MS Society of Canada or The National MS Society.

Transverse myelitis occurs when there is inflammation in the spinal cord (protective sheaths that cover nerve fibres). This causes problems with communication between the spinal cord and the rest of the body leading to pain, muscle weakness, paralysis, sensory problems and bladder/bowel dysfunction. Medications and rehabilitative therapy are often used to treat transverse myelitis.

For more information visit The Transverse Myelitis Association.

Optic neuritis occurs when there is inflammation of the optic nerve (the bundle of nerve fibres that transmits signals between your eyes and brain). This may cause pain and temporary vision loss in the affected eye. ON is often linked to multiple sclerosis (MS) or neuromyelitis optica spectrum disorder (NMOSD) as it can be the first signs of a recurrent neuroinflammatory disorder. It can also develop later in patients already diagnosed with MS or NMOSD. Additionally, ON can be seen with other demyelinating events, infections or immune diseases.

For more information, visit The National MS Society.

Neuromyelitis Optica spectrum disorder is a neuroinflamamtory condition that affects the optic nerve (nerve that conducts signals between the eye and the brain) and the spinal cord. It is characterized by the presence of both optic neuritis and transverse myelitis. These patients often experience pain in the eye, vision loss, weakness or numbness of the limbs, sensory disturbances and loss of bladder/bowel dysfunction. There is currently no cure for NMOSD however, there are therapies to treat attacks, reduce symptoms, and prevent relapses.

For more information, visit The Guthy Jackson Foundation.

Autoimmune encephalitis is an attack on the brain by our bodies’ immune system. This can cause impair in functions leading to muscle weakness, loss of balance, seizures, sleep problems, cognitive impairments, and speech impairment. Many patients recover partially or completely after treatment.

ADEM is an attack of acute and serious inflammation of the brain, optic nerve (the nerve that transmits signals between the eye and brain), and spinal cord which affects the myelin (protective sheath around nerve fibres) and grey matter in the brain. ADEM most often occurs only once and can cause seizures, headaches, confusion, visual problems, weakness, balance difficulties, and numbness. Patients with ADEM must be followed up regularly as there is a possibility of future attacks.

For more information, visit The National MS Society.

NMDA receptors are proteins in the brain that are responsible for important functions such as judgement, perceptions of reality, human interaction, memory,  and the control of unconscious functions (i.e., breathing, swallowing, etc). Anti-NMDA receptor encephalitis occurs when the body produces antibodies that attack these NMDA receptors. This may lead to seizures, flu-like symptoms, memory problems, sleep disorders, cognitive and behavioural disturbances, or problems with some of your autonomic functions. Immunotherapies can help patients with this disorder.

For more information, visit The Anti-NMDA Receptor Encephalitis Foundation.

Rasumussen’s encephalitis is characterized by inflammation of one side of the brain, which can lead to seizures. Other symptoms include weakness on one side of the body and intellectual disabilities. These patients are often treated with immunotherapy and/or surgery in addition to physiotherapy and seizure management.

ANEC is a neuroinflammatory disorder which usually presents after a viral infection and may be associated with an abnormality in the RANBP2 gene. Areas of the central nervous system affected include the deep grey matter (basal ganglia) and brainstem (pons). These children often experience respiratory or gastrointestinal problems along with a high fever. ANEC is also associated with rapid neurological decline.

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare but serious autoimmune neurological illness that typically affects toddlers and young children. Neuroblastoma (a tumour of the sympathetic nervous system) is found in up to 50% of pediatric OMAS cases , and 2-3% of children with neuroblastoma will develop OMAS. Symptoms of OMAS include uncontrolled rapid eye movements (opsoclonus), involuntary jerking of muscles (myoclonus), body coordination/balance difficulties (ataxia), and behavioural/sleep disturbances. These children are most often treated with immunotherapy.