The signs and symptoms of myelitis are determined by the causative agent (infectious or immune-mediated), location of the lesions and associated disease(s).  

These are (in alphabetical order):

• Altered sensorium
• Anorexia
• Bladder or bowel dysfunctions
• Constipation
• Difficulty in walking or any movement
• Fever
• Headache
• Impaired tendon reflexes
• Instability of a posture
• Intractable vomiting
• Limb weakness
• Malaise
• Muscle spasms
• Numbness
• Pain in the back, extremities, or abdomen
• Paralysis
• Paresthesia
• Respiratory problems
• Sexual dysfunction
• Urinary retention

The onset of symptoms in transverse myelitis (TM) is characterized by sudden neck and back pain, with loss of bladder or bowel control. Sharp pains are common. Poliomyelitis is accompanied by fever, headache, nausea, fatigue, stiffness and pain in the neck, back and extremities.

The duration of illness in TM is from a few hours to several days (acute) or more than 1 to 4 weeks (subacute). Chief complains include localized lower back pain, paresthesias (abnormal sensations of tickling, burning, pricking, or tingling) in the legs, loss of sensorium, and paraparesis. At a later stage, paraplegia may ensue, with urinary bladder and bowel dysfunctions. Some patients may experience muscle spasms, discomfort, headache, fever, anorexia and respiratory problems depending on the location of lesions in the spinal cord. 

• Fatigue

  Myalgic encephalomyelitis, a disease involving presumed inflammation of the central nervous system with symptoms of muscle pain and fatigue; the term has sometimes been used interchangeably with chronic fatigue syndrome, though there is still controversy [en.wikipedia.org]

  We ask about general symptoms (anxious mood, depressed mood, fatigue, pain, and stress) regardless of condition. Last updated: January 31, 2019 [patientslikeme.com]

  I have gone from a fatigued, sad person who suffered from constant pain to a genuinely happy, lively, healthy mum with barely any pain in my body. [whole30.com]

  Fatigue. The symptoms of transverse myelitis can appear suddenly, developing over hours to several days, or more gradually developing over a period of one to four weeks. [nationalmssociety.org]

• Constitutional Symptom

  The type of onset (acute versus subacute/chronic) along with associated symptoms such as the presence of pain, constitutional symptoms that encompass fever, malaise, weight loss or a cutaneous rash may help identify the cause of myelitis. [en.wikipedia.org]

• Fecal Incontinence

  Deficits may progress over several more days to a complete transverse sensorimotor myelopathy, causing paraplegia, loss of sensation below the lesion, urinary retention, and fecal incontinence. [msdmanuals.com]

  A common problem in spinal cord injury is difficulty with evacuation of stool, although fecal incontinence can also occur. The neurologic pathways for defecation are similar to those of the bladder. [rarediseases.org]

• Larva Migrans

  Toxocara canis is a parasite known to cause visceral larva migrans. The infection rarely affects the central nervous system but there have been several reports of myelitis caused by visceral larva migrans due to Toxocara canis. [ncbi.nlm.nih.gov]

  MRI findings of spinal visceral larva migrans of Toxocara canis. Eur J Radiol 2010 ; 75: 236 – 240. Google Scholar Medline ISI 47. Umehara, F, Ookatsu, H, Hayashi, D, Uchida, A, Douchi, Y, Kawabata, H. [doi.org]

• Back Pain

  Symptoms include back pain followed by ascending weakness in the legs. There is no cure. Many patients are left with permanent disabilities or paralysis. [medicinenet.com]

  Symptoms range from back pain to more serious problems, such as paralysis or loss of bowel control. Multiple sclerosis connection Transverse myelitis is often a onetime illness. [healthline.com]

• Myelopathy

  Spondylotic myelopathy is the commonest cause of nontraumatic myelopathy. Radiological features of spondylotic myelopathy can often overlap with inflammatory myelopathies which may lead to a delayed or incorrect diagnosis and therapy. [ncbi.nlm.nih.gov]

  Svenska synonymer Myelit Engelska synonymer Myelitides — Spinal Cord Inflammation — Inflammations, Spinal Cord — Spinal Cord Inflammations — Inflammation, Spinal Cord — Myelopathy, Inflammatory — Inflammatory Myelopathies — Inflammatory Myelopathy — Myelopathies [mesh.kib.ki.se]

  Myelitis Synonyms Infectious Myelitis Inflammation, Spinal Cord Inflammations, Spinal Cord Inflammatory Myelopathies Inflammatory Myelopathy Myelitides Myelitis, Infectious Myelitis, Subacute Necrotising Myelopathies, Inflammatory Myelopathy, Inflammatory [online-medical-dictionary.org]

  Other conditions often discussed in this group due to similar imaging include: AIDS-related myelopathy meningomyelitis post radiation myelitis spinal cord infarction spinal cord tumors compressive myelopathy References Related Radiopaedia articles Infections [radiopaedia.org]

• Paresthesia

  Case 1: a 38-years-old man presented with a 2-year history of paresthesias in the upper extremities, and one year later cramps on the right limbs and numbness over right C5 and C6 dermatomes, related to movement of the neck. [ncbi.nlm.nih.gov]

  C3 Yes No MS F, 26 Pain, paresthesia, weakness, urinary retention Medulla-C5 No Yes ADEM F, 33 Paresthesia, weakness C3–C6 No No ADEM F, 36 Paresthesia, paraparesis, urinary incontinence C1–C4 No Yes NMO M, 54 Pain, stiffness, paresthesia, paraparesis [hindawi.com]

  Weakness in the arms or legs (paraparesis) Sensory symptoms (paresthesias) such as numbness, tingling, burning, tickling, or prickling in the legs, feet or toes. [nationalmssociety.org]

• Headache

  As with other forms of primary headache, structural lesions should be excluded, particularly if the headache presents with an atypical pattern. [ncbi.nlm.nih.gov]

• Hyperreflexia

  Persistent abnormalities included detrusor hyperreflexia, dyssynergia, and areflexic bladder. [jnnp.bmj.com]

  Examination reveals moderate paraparesis with hyperreflexia, a left extensor plantar response, impaired vibratory and proprioceptive sensation, and a sensory level at T6. [nejm.org]

  Clinical presentation Typical presentation • Prior history of fever (nonspecific viral illness) • ATM, the onset of spinal cord dysfunction usually progress in 4 hours to 21 days, the patient's signs usually plateau and evolve toward spasticity/hyperreflexia [slideshare.net]

• Unable to Walk

  A 9-year-old male was admitted with unable to walk, non-sensation of legs, urinary incontinence and encopresis for 2 days. On physical examination, muscle strength was 5/5 on upper extremities and 1/5 on lower extremities. [go.gale.com]

  Early studies reported that up to one third of patients with a first episode of acute TM remained unable to walk. Most studies disclosed similar rates of poor outcome ranging from 11% to 35.8% [15]. [cureus.com]

• Sexual Dysfunction

  Snapshot A 37-year-old male presents with lower extremity numbness, weakness, and sexual dysfunction. His symptoms began 2 days prior, and has progressively worsened. Medical history is significant for pneumonia caused by Mycoplasma pneumoniae. [step2.medbullets.com]

  Sexual dysfunction, a common complication of transverse myelitis. Men may experience difficulty achieving an erection or reaching orgasm. Women may have difficulty reaching orgasm. [mayoclinic.org]

  The symptoms of TM include muscle weakness, paralysis, parasthesias or un-comfortable nerve sensations, neuropathic pain, spasticity, fatigue, depression and bladder, bowel and sexual dysfunction. [myelitis.org.uk]

• Urinary Retention

  Physical therapy may also be helpful to retrain muscles necessary for improved bladder and bowel control and relief of constipation and urinary retention. [encyclopedia.com]

  What usually begins as a sudden onset of lower back pain, muscle weakness, or abnormal sensations in the toes and feet can rapidly progress to more severe symptoms, including paralysis, urinary retention, and loss of bowel control. [aarda.org]

  Then, it rapidly progress to more severe symptoms, including paralysis, urinary retention, and loss of bowel control. [mctlawyers.com]

• Urinary Incontinence

  A 9-year-old male was admitted with unable to walk, non-sensation of legs, urinary incontinence and encopresis for 2 days. On physical examination, muscle strength was 5/5 on upper extremities and 1/5 on lower extremities. [go.gale.com]

  Pain, stiffness, paresthesia, paraparesis, urinary incontinence T4–T6 Yes No ADEM Habek et al., 2011 [5] F, 43 Quadriparesis, urinary incontinence Medulla-T1 Yes Yes NMO Fanous et al. [hindawi.com]

  This may include needing to urinate more frequently, urinary incontinence, difficulty urinating and constipation. When to see a doctor Call your doctor or get emergency medical care if you're experiencing signs and symptoms of transverse myelitis. [mayoclinic.org]

  Symptoms of TM include sudden onset of lower back pain, muscle weakness, or abnormal sensations in the toes and feet which can rapidly progress to more severe symptoms, including paralysis, urinary incontinence, increased urinary urge, urinary incontinence [cureus.com]

  Bladder and bowel problems.These problems may include an increased urinary urge, urinary incontinence, difficulty urinating and constipation. Prognosis of TM Generally, prognosis for complete recovery from TM is not good. [mytm.ca]

Diagnosis of TM:

• In addition to medical history and neurologic examination, magnetic resonance imaging (MRI) of the spinal cord is needed, with or without paramagnetic contrast (with gadolinium) to visualize the lesions and cord swelling. Contrast enhancement can facilitate the observation of inflammation or gross abnormality in the cord. 
• Spinal tap to obtain a sample of CSF to assess leukocytosis (increased white blood cell counts) as a measure of presence and degree of inflammation.
• Blood tests to rule out concomitant disorders e.g., HIV infection, systemic lupus erythematosus,  avitaminosis B12, NMO-IgG in Devic's disease, MS, etc.

In the absence of an identifiable etiologic agent the condition is diagnosed to be idiopathic transverse myelitis (IATM).

Early diagnosis and treatment is important. Given the varied nature of myelitis, only after thorough consideration of probable cause and clinical course of each type of myelitis, may one prescribe the following modes of treatment: 

• Intravenous steroids - high IV dose of methyl-prednisolone for 3-5 days.
• Plasma exchange or plasmapheresis (PLEX) - for patients not responding to steroid therapy.
• Immunotherapy - medications that modulate or suppress the immune system.
• Rehabilitation - radical treatment and long-term management of symptoms.
• Physical therapy - for long-term recovery and restoration of functionality; it teaches the patient the use of self-help devises.
• Occupational therapy - to develop the ability to perform daily routinary activities.
• Psychotherapy - to alleviate anxiety neurosis, sexual dysfunction and to develop coping mechanisms.

Recovery from transverse myelitis is expected within 2 to 12 weeks after the onset of symptoms, or longer; it may extend up to 2 years and beyond in some cases. Otherwise the likelihood for complete recovery is nil without evident clinical improvement within 3 to 6 months. Partial recovery, if at all, may be expected with aggressive physical therapy and rehabilitation. 

In retrospect, with conservative therapy, one third of patients recover sufficiently as to be able to resume certain activities normally such as walking, with improved urinary and bowel functions and minimal paresthesia. A third group may recover partially with residual deficits such as spastic gait, sensory dysfunction, and urinary urgency or incontinence. Refractory patients may remain bedridden or wheelchair-bound and unable to perform normal daily functions. It has been shown that prognosis is poor with rapid onset of symptoms. Nonetheless, radical therapy and long-term rehabilitation should be undertaken. 

Causes of myelitis:

• Bacterial: e.g., Mycobacterium tuberculosis.
• Viral: e.g., poliovirus (human enterovirus, Family Picornaviridae), HIV (human immunodeficiency virus) can cause chronic myelitis). 
• Fungal: e.g., Cryptococcus neoformans, Histoplasma capsulatum.
• Autoimmune conditions: direct attack on nerve cells. 
• Parasites: e.g., Schistosoma spp., Toxocara canis
• Vaccination

In the USA less than 200,000 people are affected by myelitis, hence, it is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health. However, this is not the case particularly in the tropics where infectious diseases are highly prevalent. 

A nationwide outbreak of acute myelitis in children has been reported in the literature [1]. Transverse myelitis (TM) affects all persons regardless  of age, gender, ethnic origin; evidently, with no hereditary predisposition. New cases are seen each year in the high risk groups of 10 to 19 years and 30 to 39 years. The annual incidence of TM in the U.S. is around 1,400; 33,000 Americans have some kind of disability that is associated with TM. Acute transverse myelitis (ATM) is either idiopathic, i.e., of unknown etiology (IATM) or secondary, i.e., associated with a known cause or condition (SATM). IATM is an immune-mediated demyelinating inflammation of the spinal cord. The annual incidence of IATM is estimated between 1 in 1,000,000 and 1 in 250,000 population.

SATM is linked to an infectious disease entity or an autoimmune condition. Other parts of the nervous system may be involved thus, the optic nerves in multiple sclerosis (MS) and neuromyelitis optica (NMO) or Devic's disease, the peripheral nerves in systemic lupus erythematosus (SLE) or anti-Ro/SS-A antibodies in Sjogren's syndrome. Direct attack or invasion of the spinal cord by parasites and microbial pathogens can likewise cause SATM. The incidence of SATM depends on a multiplicity of causes hence it is difficult to come up with a composite estimate. 

The histopathology of acute transverse myelitis (ATM) is confined to the spinal cord. For example, the histology differs from multiple sclerosis. In MS, axons are usually intact and lesions are few and scattered (primary demyelination) whereas in ATM there is extensive demyelination and damage to axons; lesions may be cavitary in severe transverse myelitis.

Necrotizing processes  are involved in addition to inflammation and demyelination as in Devic's disease, acute hemorrhagic leukoencephalitis and progressive necrotizing myelopathy. These diseases differ in their clinical course, histology, serum marker and nature of the lesions. Neuromyelitis optica (NMO), or Devic's disease, is characterized by an immune attack on the optic nerve and spinal cord. Serological tests in 70% of patients with NMO have an IgG antibody called aquaporin-4 (AQP4). In both Devic's disease and TM, lesions are located in the center of the cord with intact sections in subpial areas. Cerebrospinal fluid (CSF) shows elevated protein with transient or absent oligoclonal bands. The spinal cord is swollen in MRI. In a study, antibodies against myelin-associated glycoprotein were found in all cases of Devic's disease [2]. The finding of aquaporin 4 in NMO differentiates cases of optic neuritis and myelitis from multiple sclerosis, heretofore, necessitating a different therapeutic approach [3].

Inflammatory cytokines e.g., IL-6 is increased in CSF in MS and inflammatory neurologic diseases. The elevation can reach 300-fold in cases of idiopathic transverse myelitis versus non-IAMT [4]. 

• To prevent the occurrence of post-vaccinal myelitis forego new vaccination during the acute stage of the disease or when there is a strong index of suspicion of possible myelitis.
• Prophylactic measures and/or vaccination against influenza in upper respiratory tract infections; supportive treatment with sunlight and vitamin D, eliminate habit of smoking and weight control in MS.
• Modification of these risk factors is likewise recommended in idiopathic transverse myelitis.

When the prospect of clinical cure appear to outweigh the associated risk of neurological problems arising after vaccination, which is considered very low, the choice of preventive measure should be based on that premise.

Myelitis is a disorder of the central nervous system (CNS) particularly the spinal cord. There are several types of myelitis each with a different etiology namely:

• Grey matter - consisting of demyelinated neurons (nerve cells without sheaths), as in poliomyelitis, a viral infection causing muscle weakness and paralysis.
• White matter - myelinated (with sheaths) neurons, as in leukomyelitis and herpes vrus infection.
• Transverse myelitis - inflammatory demyelinated nerves on both sides of the spinal cord. 
• Meningococcal myelitis - lesions in the meninges (the protective membrane around the brain and spinal cord). 
• Multiple sclerosis (MS or encephalomyelitis) - damaged nerve coverings in the brain and spine, causing various physical and mental disabilities.
• Post-vaccinal myelitis - side effects of vaccination.

• Myelitis is a disease entity which involves inflammation of the spinal cord. Transverse myelitis (TM) means that the inflammation occurs on both sides of the spinal cord. The exact cause of TM is unknown.
• Inflammation may be due to any of the following i.e., infection with disease-causing organisms, insufficient blood flow through blood vessels in the spinal cord, or to the effect of immune processes which can damage myelin, the membrane covering nerve fibers.  This causes lesions that disrupt the transmission of impulses between the nerves in the spinal cord and the rest of the body.
• Transverse myelitis may likewise develop as a complication of infectious diseases or as an adverse effect of vaccinations, as in chickenpox and rabies.

• The duration of symptoms of TM may last for few hours to several weeks starting as a sudden attack of muscle weakness, abnormal sensations in the toes and feet or lower back pain, rapidly progressing to more severe stages, with paralysis, urinary bladder and bowel dysfunctions.
• Some people may recover fully or partially from TM with little or no residual effects, others may suffer permanent disabilities that prevent them from resuming normal daily living.
• Demyelination at the thoracic level results into problems with leg movement, bowel and bladder control; these functions are dependent upon signals from the lower regions of the spinal cord.
• Pain, the chief complain in 50% of TM patients, includes lower back or sharp, shooting sensations in the extremities and around the torso. About 80 percent experience heightened sensitivity to touch and temperature changes, and discomfort or pain (allodynia). 
• Medical history and thorough neurological examination are important for effective treatment.

1. CDC. Acute flaccid myelitis: interim considerations for clinical management. Atlanta, GA: US Department of Health and Human Services, CDC; 2014. Available at http://www.cdc.gov/ncird/downloads/acute-flaccid-myelitis.pdf
2. Haase CG, Schmidt S. Detection of brain-specific autoantibodies to myelin oligodendrocyte glycoprotein, S100beta and myelin basic protein in patients with Devic’s neuromyelitis optica. Neurosci Lett 2001;307:131-3.
3. Lennon VA, Wingerchuk DM, Kryzer TJ, et al. A serum autoantibody marker of neuromyelitis optica: distinction from multiple sclerosis. Lancet 2004;364:2106-12.
4. Kaplin AI, Deshpande DM, Scott E, et al. IL-6 induces regionally selective spinal cord injury in patients with the neuroinflammatory disorder transverse myelitis. J Clin Invest 2005;115:2731-41.