Acute flaccid myelitis: Difference between revisions
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*[[Quadriplegia]] is a rare finding in infants. | *[[Quadriplegia]] is a rare finding in infants. | ||
=== Laboratory Findings === | === Laboratory Findings === | ||
===Non specific tests=== | |||
====Blood tests==== | |||
It is performed routinely to any suspected meningitis patients. It includes the following: | |||
*[[CBC]] | |||
*[[Blood culture]] | |||
*[[PT]] and [[PTT]] | |||
*[[Glucose]] level | |||
*[[Creatine]] level | |||
====Virus detection==== | |||
Virus may be detected through two ways: | |||
*Samples can be taken by different ways from the suspected meningitis patients to detect the virus causing the disease.They may be collected for testing by:<ref name= "Viral meningitis"> CDC https://www.cdc.gov/meningitis/viral.html Accessed on April 20, 2017 </ref> | |||
**[[Nose]] swabbing | |||
**[[Throat]] swabbing | |||
**[[Rectum]] swabbing | |||
**Taking a [[stool]] sample | |||
**Drawing [[fluid]] from around your [[spinal cord]]. | |||
*[[Polymerase chain reaction|Polymerase Chain Reaction]] ([[PCR]]) can be used to detect the [[viruses]] in the [[blood]]. It can detect the [[DNA]] of the viruses like the [[enteroviruses]] and [[herpes simplex]] viruses.<ref name="pmid22608699">{{cite journal| author=Cantey JB, Mejías A, Wallihan R, Doern C, Brock E, Salamon D et al.| title=Use of blood polymerase chain reaction testing for diagnosis of herpes simplex virus infection. | journal=J Pediatr | year= 2012 | volume= 161 | issue= 2 | pages= 357-61 | pmid=22608699 | doi=10.1016/j.jpeds.2012.04.009 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22608699 }} </ref> | |||
===Specific tests=== | |||
Specific diagnostic tests include [[lumbar puncture]] with CSF examination. CSF examination findings in viral meningitis are as follows: | |||
{| style="border: 0px; font-size: 90%; margin: 3px;" align=center | |||
|+ | |||
! style="background: #4479BA; width: 150px;" | {{fontcolor|#FFF|Cerebrospinal fluid level}} | |||
! style="background: #4479BA; width: 350px;" | {{fontcolor|#FFF|Normal level}} | |||
! style="background: #4479BA; width: 350px;" | {{fontcolor|#FFF|Viral meningitis}}<ref name="pmid10654948">{{cite journal| author=Negrini B, Kelleher KJ, Wald ER| title=Cerebrospinal fluid findings in aseptic versus bacterial meningitis. | journal=Pediatrics | year= 2000 | volume= 105 | issue= 2 | pages= 316-9 | pmid=10654948 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10654948 }} </ref> | |||
|- | |||
| style="padding: 5px 5px; background: #DCDCDC;" | '''Cells/ul''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''< 5''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''>100''' | |||
|- | |||
| style="padding: 5px 5px; background: #DCDCDC;" |'''Cells''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''Lymphos:Monos 7:3''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''Lymphocytes>granulocytes''' | |||
|- | |||
| style="padding: 5px 5px; background: #DCDCDC;" |'''Total protein (mg/dl''') | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''45-60''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''Normal or slightly elevated''' | |||
|- | |||
| style="padding: 5px 5px; background: #DCDCDC;" |'''Glucose ratio (CSF/plasma)<ref name="pmid24326618">{{cite journal| author=Chow E, Troy SB| title=The differential diagnosis of hypoglycorrhachia in adult patients. | journal=Am J Med Sci | year= 2014 | volume= 348 | issue= 3 | pages= 186-90 | pmid=24326618 | doi=10.1097/MAJ.0000000000000217 | pmc=4065645 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24326618 }} </ref>''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''> 0.5''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''>0.6 | |||
|- | |||
| style="padding: 5px 5px; background: #DCDCDC;" |'''Lactate (mmols/l)<ref name="pmid22880096">{{cite journal| author=Leen WG, Willemsen MA, Wevers RA, Verbeek MM| title=Cerebrospinal fluid glucose and lactate: age-specific reference values and implications for clinical practice. | journal=PLoS One | year= 2012 | volume= 7 | issue= 8 | pages= e42745 | pmid=22880096 | doi=10.1371/journal.pone.0042745 | pmc=3412827 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22880096 }} </ref>''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''< 2.1''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''< 2.1''' | |||
|- | |||
| style="padding: 5px 5px; background: #DCDCDC;" |'''Others''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''ICP:6-12 (cm H2O)''' | |||
| style="padding: 5px 5px; background: #F5F5F5;" |'''Throat swap''' | |||
|- | |||
|} | |||
Video explaining the lumbar puncture procedure: | |||
{{#ev:youtube|weoY_9tOcJQ}} | |||
=== Imaging Findings === | === Imaging Findings === |
Revision as of 19:05, 14 November 2018
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Syed Hassan A. Kazmi BSc, MD [2]
Synonyms and keywords:; Acute flaccid paralysis, acute flaccid paralysis with anterior myelitis, paralysis with anterior myelitis, AFM, Enterovirus D68-Associated Anterior Myelitis
Overview
Historical Perspective
- In 2014, physicians in California and Colorado (USA) noted an increase in the number of patients presenting with the acute onset of flaccid paralysis and MRI findings consistent with lesions in the gray matter of the spinal cord.
- In 2014, a total of 120 cases were identified in the US and 22 were identified in 2015
- In 2016, 145 cases of AFM were diagnosed across the USA.
Causes
Acute flaccid myelitis (AFM) may be caused by viral infections or environmental toxins. The following viruses are known to be associated with AFM:
- West Nile Virus
- Coxsackievirus
- Adenovirus
- Poliovirus
- Enterovirus 71 (EV 71) and Entervirus D68 (EV 68)
Differentiating Acute Flaccid Myelitis From Other Diseases
The following table differentiates acute flaccid myelitis from other diseases that cause muscle weakness, hypotonia, and flaccid paralysis:
Diseases | History and Physical | Diagnostic tests | Other Findings | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Motor Deficit | Sensory deficit | Cranial nerve Involvement | Autonomic dysfunction | Proximal/Distal/Generalized | Ascending/Descending/Systemic | Unilateral (UL)
or Bilateral (BL) or No Lateralization (NL) |
Onset | Lab or Imaging Findings | Specific test | ||
Adult Botulism | + | - | + | + | Generalized | Descending | BL | Sudden | Toxin test | Blood, Wound, or Stool culture | Diplopia, Hyporeflexia, Hypotonia, possible respiratory paralysis |
Infant Botulism | + | - | + | + | Generalized | Descending | BL | Sudden | Toxin test | Blood, Wound, or Stool culture | Flaccid paralysis (Floppy baby syndrome), possible respiratory paralysis |
Guillian-Barre syndrome | + | - | - | - | Generalized | Ascending | BL | Insidious | CSF: ↑Protein
↓Cells |
Clinical & Lumbar Puncture | Progressive ascending paralysis following infection, possible respiratory paralysis |
Eaton Lambert syndrome | + | - | + | + | Generalized | Systemic | BL | Intermittent | EMG, repetitive nerve stimulation test (RNS) | Voltage gated calcium channel (VGCC) antibody | Diplopia, ptosis, improves with movement (as the day progresses) |
Myasthenia gravis | + | - | + | + | Generalized | Systemic | BL | Intermittent | EMG, Edrophonium test | Ach receptor antibody | Diplopia, ptosis, worsening with movement (as the day progresses) |
Electrolyte disturbance | + | + | - | - | Generalized | Systemic | BL | Insidious | Electrolyte panel | ↓Ca++, ↓Mg++, ↓K+ | Possible arrhythmia |
Organophosphate toxicity | + | + | - | + | Generalized | Ascending | BL | Sudden | Clinical diagnosis: physical exam & history | Clinical suspicion confirmed with RBC AchE activity | History of exposure to insecticide or living in farming environment. with : Diarrhea, Urination, Miosis, Bradycardia, Lacrimation, Emesis, Salivation, Sweating |
Tick paralysis (Dermacentor tick) | + | - | - | - | Generalized | Ascending | BL | Insidious | Clinical diagnosis: physical exam & history | - | History of outdoor activity in Northeastern United States. The tick is often still latched to the patient at presentation (often in head and neck area) |
Tetrodotoxin poisoning | + | - | + | + | Generalized | Systemic | BL | Sudden | Clinical diagnosis: physical exam & dietary history | - | History of consumption of puffer fish species. |
Stroke | +/- | +/- | +/- | +/- | Generalized | Systemic | UL | Sudden | MRI +ve for ischemia or hemorrhage | MRI | Sudden unilateral motor and sensory deficit in a patient with a history of atherosclerotic risk factors (diabetes, hypertension, smoking) or atrial fibrillation. |
Poliomyelitis | + | + | + | +/- | Proximal > Distal | Systemic | BL or UL | Sudden | PCR of CSF | Asymmetric paralysis following a flu-like syndrome. | |
Transverse myelitis | + | + | + | + | Proximal > Distal | Systemic | BL or UL | Sudden | MRI & Lumbar puncture | MRI | History of chronic viral or autoimmune disease (e.g. HIV) |
Neurosyphilis | + | + | - | +/- | Generalized | Systemic | BL | Insidious | MRI & Lumbar puncture | CSF VDRL-specifc
CSF FTA-Ab -sensitive |
History of unprotected sex or multiple sexual partners.
History of genital ulcer (chancre), diffuse maculopapular rash. |
Muscular dystrophy | + | - | - | - | Proximal > Distal | Systemic | BL | Insidious | Genetic testing | Muscle biopsy | Progressive proximal lower limb weakness with calf pseudohypertrophy in early childhood. Gower sign positive. |
Multiple sclerosis exacerbation | + | + | + | + | Generalized | Systemic | NL | Sudden | ↑CSF IgG levels
(monoclonal) |
Clinical assessment and MRI | Blurry vision, urinary incontinence, fatigue |
Amyotrophic lateral sclerosis | + | - | - | - | Generalized | Systemic | BL | Insidious | Normal LP (to rule out DDx) | MRI & LP | Patient initially presents with upper motor neuron deficit (spasticity) followed by lower motor neuron deficit (flaccidity). |
Inflammatory myopathy | + | - | - | - | Proximal > Distal | Systemic | UL or BL | Insidious | Elevated CK & Aldolase | Muscle biopsy | Progressive proximal muscle weakness in 3rd to 5th decade of life. With or without skin manifestations. |
Epidemiology and Demographics
Incidence and Prevalence
USA
- From June 1, 2012 to July 31, 2015, 59 reported cases met the California Department of Public Health (CDPH) case definition of acute flaccid myelitis (AFM), which defines AFM as acute onset of flaccid limb paralysis along with a lesion in the gray matter of the spinal cord.
- Between August and December of 2014, 120 children from 34 US states met the criteria of AFM as outlined by the CDC.
- From August 2014 through October 2018, CDC has received information on a total of 404 confirmed cases of acute flaccid myelitis (AFM) across the US; most of the cases have occurred in children
- In 2015, 22 people were confirmed to have AFM. (Note: The cases occurred in 17 states across the U.S.)
- In 2016, 149 people were confirmed to have AFM. (Note: The cases occurred in 39 states across the U.S. and DC)
- In 2017, CDC received information for 33 confirmed cases of AFM. (Note: The cases occurred in 16 states across the U.S.)
- In October 2018, the New York State Department of Health (NYSDOH) confirmed 39 cases of the enterovirus EV-D68 in children across the state which was associated with an increase in number of cases of AFM.
![](/images/e/e7/AFM.jpg)
Age
- AFM affects older children. Median age at presentation is 7 years.
Gender
- Male children are affected more frequently than females.
Risk Factors
The following risk factors increase the risk of development of AFM:
- Pulmonary comorbities (Asthma, COPD)
- Immunocompromised states (Immunosuppressants, organ transplantation, diabetes, systemic autoimmune diseases, hematologic malignancies)
Natural History, Complications and Prognosis
Natural History
- The clinical course of AFM typically consists of three phases:
- Prodormal phase
- Progressive neurological injury phase
- Convalescent phase
Prodormal phase
- A prodromal, often febrile, illness often precedes the onset of neurological deficits in most patients by a median of 5 days.
- The prodormal period consists of respiratory symptoms such as rhinorrhea, cough, or pharyngitis and/or gastrotestinal symptoms such as nausea, vomiting or diarrhea.
- Some patients report clinical improvement in their preceding illness before return of fever accompanied by headaches, stiff neck, or pain in the neck, back, or affected limb around the time of neurological deficit onset
Progressive neurological injury
- The pattern of limb weakness in AFM corresponds to a lower motor neuron lesion and upper extremities are more commonly affected.
- Involvement of cranial nerves points towards lesions in the cranial nerve motor nuclei of the brainstem
- On CSF examination, mild pleocytosis with mildly elevated protein may be seen
- On MRI, confluent, longitudinally extensive gray matter lesions may be seen in spinal cord. This may progress to nerve root enhancement on MRI in 2-3 weeks.
- On electromyography (EMG), reduced recruitment of motor unit potentials (MUPs) and low amplitude of compound muscle action potentials may be seen.
Convalescent phase
- Months after the initial acute neurological illness, patients suffering from AFM may smild improvements with rehabilitation therapies.
- On CSF examination, pleocytosis may resolve and protein remains elevated
- On EMG, fibrillations may be seen
Complications
AFM may lead to the development of following complications:
- Respiratory failure
- Urinary tract infections
- Skin ulcers and traumatic injury (specially in the affected extremity)
- Progressive muscular atrophy
Prognosis
- Physical and occupational therapy are especially important during recovery from AFM
- The extent of recovery varies. Although some people may make a full recovery, most have continued muscle weakness even after a year.
- Long term outcomes for patients suffering from AFM are not known.
Diagnosis
Diagnostic Criteria
Diagnosis | Criteria |
---|---|
Confirmed |
AND
|
Probable |
AND
|
Symptoms
The following are the symptoms of acute flaccid myelitis:
- Acute onset of flaccid limb paralysis (asymmetric)
- Fever
- Pain in the paralytic limb
- Eyelid drooping
- Difficulty with swallowing or slurred speech
- Cranial nerve abnormalities
- Headache
- Neck pain
- Bowel/bladder changes
Physical Examination
Temperature
- A fever is often present
Extremities
- Weakness of the extremities, predominantly of the proximal muscles, is characteristic of this form of the disease. Lower extremities are more often involved.
- Asymmetrical flaccid paralysis, predominantly of the proximal muscles, is characteristic of this form of the disease. Lower extremities are more often involved.
Neurologic
- Meningeal signs may be present on physical exam, such as:[1]
- Initially hyperactive deep tendon reflexes, that later become absent.
- Common combinations of limb involvement include:
- One lower limb, followed by one upper limb
- Both lower limbs, followed by both upper limbs
- Quadriplegia is a rare finding in infants.
Laboratory Findings
Non specific tests
Blood tests
It is performed routinely to any suspected meningitis patients. It includes the following:
Virus detection
Virus may be detected through two ways:
- Samples can be taken by different ways from the suspected meningitis patients to detect the virus causing the disease.They may be collected for testing by:[2]
- Polymerase Chain Reaction (PCR) can be used to detect the viruses in the blood. It can detect the DNA of the viruses like the enteroviruses and herpes simplex viruses.[3]
Specific tests
Specific diagnostic tests include lumbar puncture with CSF examination. CSF examination findings in viral meningitis are as follows:
Cerebrospinal fluid level | Normal level | Viral meningitis[4] |
---|---|---|
Cells/ul | < 5 | >100 |
Cells | Lymphos:Monos 7:3 | Lymphocytes>granulocytes |
Total protein (mg/dl) | 45-60 | Normal or slightly elevated |
Glucose ratio (CSF/plasma)[5] | > 0.5 | >0.6 |
Lactate (mmols/l)[6] | < 2.1 | < 2.1 |
Others | ICP:6-12 (cm H2O) | Throat swap |
Video explaining the lumbar puncture procedure: {{#ev:youtube|weoY_9tOcJQ}}
Imaging Findings
Treatment
Medical Therapy
- There is no specific treatment for AFM.
- Treatments that have been tried include:
- Immunoglobulin (IVIG)
- Plasma exchange
- Physiotherapy
- Occupational therapy
- There is no clear evidence that any of these treatments affect recovery. The extent of recovery varies. Although some people may make a full recovery, most have continued muscle weakness even after a year.
Surgical Therapy
Prevention
- ↑ Mandell, Gerald (2010). Mandell, Douglas, and Bennett's principles and practice of infectious diseases. Philadelphia, PA: Churchill Livingstone/Elsevier. ISBN 0443068399.
- ↑ CDC https://www.cdc.gov/meningitis/viral.html Accessed on April 20, 2017
- ↑ Cantey JB, Mejías A, Wallihan R, Doern C, Brock E, Salamon D; et al. (2012). "Use of blood polymerase chain reaction testing for diagnosis of herpes simplex virus infection". J Pediatr. 161 (2): 357–61. doi:10.1016/j.jpeds.2012.04.009. PMID 22608699.
- ↑ Negrini B, Kelleher KJ, Wald ER (2000). "Cerebrospinal fluid findings in aseptic versus bacterial meningitis". Pediatrics. 105 (2): 316–9. PMID 10654948.
- ↑ Chow E, Troy SB (2014). "The differential diagnosis of hypoglycorrhachia in adult patients". Am J Med Sci. 348 (3): 186–90. doi:10.1097/MAJ.0000000000000217. PMC 4065645. PMID 24326618.
- ↑ Leen WG, Willemsen MA, Wevers RA, Verbeek MM (2012). "Cerebrospinal fluid glucose and lactate: age-specific reference values and implications for clinical practice". PLoS One. 7 (8): e42745. doi:10.1371/journal.pone.0042745. PMC 3412827. PMID 22880096.