• In the pathogenesis of transverse myelitis, a variety of immunological mechanisms may cause pathological substrate and dysfunction of neural cells within the spinal cord.

• Transverse myelitis is the result of progressive demyelination and axonal loss in addition to gray matter involvement, necrosis and cavitation.
• It is understood that infections may cause transverse myelitis by:
  • Direct tissue damage
  • Immune-mediated infection-triggered tissue damage
• Multiple sclerosis is the other cause to the transverse myelitis and it sometimes transverse myelitis can appear as the first symptom of Multiple sclerosis.
• Acute partial transverse myelitis may be predictive of a subsequent diagnosis of multiple sclerosis in children.
• Invariable histopathological findings of transverse myelitis include:
  • Perivascular spread of monocytes
  • Focal areas of lymphocytes infiltrating
  • Astroglial and microglial activation

• Other histopathological findings of transverse myelitis include:
  • Infiltration of CD4⁺ and CD8⁺ T-lymphocytes
  • Typically preservation of the subpial parenchyma suggesting ischemia as the ultimate cause of the cord lesions in transverse myelitis

Conditions that may cause transverse myelitis include:

• Various infectionsin 30% to 60% of the cases:
  • Herpesviridae
  • Enteroviruses
  • Influenza viruses
  • Adenoviruses
  • Coxsackieviruses
  • Enteric cytopathogenic human orphan (ECHO) virus
  • Hepatitis A virus
  • Lymphocytic choriomeningitis virus (LCMV)
  • Mumps virus
  • Measles virus
  • Rubella virus
  • Poliovirus
  • Rubeola virus
  • Dengue virus
  • Russian spring-summer encephalitis virus
  • Varicella virus
  • Mycoplasma pneumonia bacteria
  • Legionella pneumonia bacteria
  • Pulmonary tuberculosis
  • Borrelia (Lyme disease)
  • Listeria
  • Bartonella (cat scratch disease)
• Vaccination
  • About 30% of pediatric cases are preceded with immunizations within one month of disease onset

Infections can cause transverse myelitis through two main mechanisms:

1. Direct tissue damage
2. Immune-mediated infection-triggered tissue damage which may be due to: Molecular mimicry or superantigen effect

• This immune response may be caused either by T-cell mediated immune response or by antibody-mediated immune response.

A non-microbial related immune dysfunction by the presence of autoantibodies has been also proposed in the immunopathogenesis of transverse myelitis.

In the spinal fluid of patients with transverse myelitis, Interleukin 6 (IL-6) levels were also markedly elevated.

• The lesions in acute transverse myelitis are invariably limited to the spinal cord.^[1][2]
• There is no involvement of other structures in the central nervous system.^[1]
• The spinal cord involvement in patients with transverse myelitis is usually central, uniform and symmetric but in patients with multiple sclerosis it typically affects the spinal cord in a patchy way and the lesions are usually peripheral.

• In the pathogenesis of transverse myelitis, a variety of immunological mechanisms may cause pathological substrate and dysfunction of neural cells within the spinal cord.^[3]

• Transverse myelitis is the result of progressive demyelination and axonal loss in addition to gray matter involvement, necrosis and cavitation.^[1]
• It is understood that infections may cause transverse myelitis by: ^[1]
  • Direct tissue damage
  • Immune-mediated infection-triggered tissue damage
• Multiple sclerosis is the other cause to the transverse myelitis and it sometimes transverse myelitis can appear as the first symptom of Multiple sclerosis.^[1]
• Acute partial transverse myelitis may be predictive of a subsequent diagnosis of multiple sclerosis in children.^[4]
• Invariable histopathological findings of transverse myelitis include:^[1]
  • Perivascular spread of monocytes
  • Focal areas of lymphocytes infiltrating
  • Astroglial and microglial activation

• Other histopathological findings of transverse myelitis include:^[1][5]
  • Infiltration of CD4⁺ and CD8⁺ T-lymphocytes
  • Typically preservation of the subpial parenchyma suggesting ischemia as the ultimate cause of the cord lesions in transverse myelitis

Conditions that may cause transverse myelitis include:

• Various infectionsin 30% to 60% of the cases:^{[1][6][7][8][9][10][11][12][13][14]}
  • Herpesviridae
  • Enteroviruses
  • Influenza viruses
  • Adenoviruses
  • Coxsackieviruses
  • Enteric cytopathogenic human orphan (ECHO) virus
  • Hepatitis A virus
  • Lymphocytic choriomeningitis virus (LCMV)
  • Mumps virus
  • Measles virus
  • Rubella virus
  • Poliovirus
  • Rubeola virus
  • Dengue virus
  • Russian spring-summer encephalitis virus
  • Varicella virus
  • Mycoplasma pneumonia bacteria
  • Legionella pneumonia bacteria
  • Pulmonary tuberculosis
  • Borrelia (Lyme disease)
  • Listeria
  • Bartonella (cat scratch disease)
• Vaccination^[1][15]
  • About 30% of pediatric cases are preceded with immunizations within one month of disease onset

Infections can cause transverse myelitis through two main mechanisms:^[1][14][16]

1. Direct tissue damage
2. Immune-mediated infection-triggered tissue damage which may be due to: Molecular mimicry or superantigen effect

• This immune response may be caused either by T-cell mediated immune response or by antibody-mediated immune response.

A non-microbial related immune dysfunction by the presence of autoantibodies has been also proposed in the immunopathogenesis of transverse myelitis.^{[1][17][18][19]}

In the spinal fluid of patients with transverse myelitis, Interleukin 6 (IL-6) levels were also markedly elevated.^[1][8][20]

Conditions associated with transverse myelitis include:^{[21][22][1][3][23]}

• Various infections
• Systemic autoimmune diseases like:
  • Lupus erythematosus
  • Sjögren’s syndrome
  • Sarcoidosis
  • Optic neuritis
  • multiple sclerosis

Findings on microscopic histopathological analysis of transverse myelitis include:^[24][25]

• Perivascular lymphocytic infiltrates
• Axonal injury
• Necrosis and demyelination