Podcast
Questions and Answers
What is a common environmental trigger for ADEM?
What is a common environmental trigger for ADEM?
- Sun exposure
- Fungal infections
- Viral infections (correct)
- Allergies
ADEM is exclusively seen in older adults.
ADEM is exclusively seen in older adults.
False (B)
What type of response is triggered when T cells mistakenly target myelin in ADEM?
What type of response is triggered when T cells mistakenly target myelin in ADEM?
Immune response
ADEM can be considered an __________ disease.
ADEM can be considered an __________ disease.
Match the following symptoms with their correct descriptions in ADEM:
Match the following symptoms with their correct descriptions in ADEM:
Which cytokine is NOT involved in the inflammatory response of ADEM?
Which cytokine is NOT involved in the inflammatory response of ADEM?
ADEM can lead to injury in both white and gray matter.
ADEM can lead to injury in both white and gray matter.
List two common symptoms of ADEM.
List two common symptoms of ADEM.
The process by which T cells are activated and target myelin is known as __________ mimicry.
The process by which T cells are activated and target myelin is known as __________ mimicry.
Which of the following best describes the role of cytokines in ADEM?
Which of the following best describes the role of cytokines in ADEM?
Which of the following symptoms are indicative of encephalopathy?
Which of the following symptoms are indicative of encephalopathy?
Ataxia is a symptom of ADEM due to demyelination in the cerebellum.
Ataxia is a symptom of ADEM due to demyelination in the cerebellum.
What is the first-line diagnostic test for ADEM?
What is the first-line diagnostic test for ADEM?
Injury to the anterior gray horn can result in _____ motor neuron lesions.
Injury to the anterior gray horn can result in _____ motor neuron lesions.
Match the neurological symptoms with their corresponding impairments:
Match the neurological symptoms with their corresponding impairments:
What indicates demyelination in T1 and T2 MRI sequences?
What indicates demyelination in T1 and T2 MRI sequences?
Corticosteroids are the only treatment option for ADEM.
Corticosteroids are the only treatment option for ADEM.
What type of infections should be empirically treated when ADEM is suspected?
What type of infections should be empirically treated when ADEM is suspected?
Increased IgG antibodies in the cerebrospinal fluid are indicative of _____ banding.
Increased IgG antibodies in the cerebrospinal fluid are indicative of _____ banding.
Which tract damage leads to decreased sensation of crude touch and pressure?
Which tract damage leads to decreased sensation of crude touch and pressure?
Which of the following is a common presentation of ADEM in younger patients?
Which of the following is a common presentation of ADEM in younger patients?
ADEM is primarily seen in older individuals.
ADEM is primarily seen in older individuals.
Name one genetic factor that may contribute to the susceptibility of ADEM.
Name one genetic factor that may contribute to the susceptibility of ADEM.
ADEM may arise following infections with __________ or the MMR vaccine.
ADEM may arise following infections with __________ or the MMR vaccine.
Match the symptoms of ADEM with their respective descriptions:
Match the symptoms of ADEM with their respective descriptions:
Which cytokine is NOT involved in the inflammatory response of ADEM?
Which cytokine is NOT involved in the inflammatory response of ADEM?
Corticosteroids are the sole treatment option for ADEM.
Corticosteroids are the sole treatment option for ADEM.
The autoimmune response in ADEM may be triggered by __________ mimicry.
The autoimmune response in ADEM may be triggered by __________ mimicry.
Describe the role of the blood-brain barrier in the pathophysiology of ADEM.
Describe the role of the blood-brain barrier in the pathophysiology of ADEM.
What is a common environmental trigger of ADEM?
What is a common environmental trigger of ADEM?
Which of the following is a hallmark symptom of ADEM?
Which of the following is a hallmark symptom of ADEM?
Demyelination in ADEM only affects white matter.
Demyelination in ADEM only affects white matter.
What diagnostic imaging technique is primarily used to identify demyelination in ADEM?
What diagnostic imaging technique is primarily used to identify demyelination in ADEM?
An injury to the anterior horn can lead to _____ motor neuron lesions.
An injury to the anterior horn can lead to _____ motor neuron lesions.
Match the types of sensory deficits with their corresponding tracts:
Match the types of sensory deficits with their corresponding tracts:
What is the initial treatment protocol for ADEM?
What is the initial treatment protocol for ADEM?
MRI T1 sequences typically show hyper-intense lesions indicating demyelination.
MRI T1 sequences typically show hyper-intense lesions indicating demyelination.
Name one common virus that may trigger ADEM.
Name one common virus that may trigger ADEM.
In ADEM, patients may experience _____ and altered sensations.
In ADEM, patients may experience _____ and altered sensations.
Which of the following findings would indicate oligoclonal banding in CSF analysis?
Which of the following findings would indicate oligoclonal banding in CSF analysis?
What is the typical demographic for individuals affected by ADEM?
What is the typical demographic for individuals affected by ADEM?
ADEM is considered a purely genetic disease.
ADEM is considered a purely genetic disease.
Name one viral infection that is a known environmental trigger for ADEM.
Name one viral infection that is a known environmental trigger for ADEM.
In ADEM, cytokines promote increased __________ permeability, allowing immune cells to flood the affected area.
In ADEM, cytokines promote increased __________ permeability, allowing immune cells to flood the affected area.
Match the following symptoms of ADEM with their descriptions:
Match the following symptoms of ADEM with their descriptions:
Which of the following cytokines is involved in the inflammatory response of ADEM?
Which of the following cytokines is involved in the inflammatory response of ADEM?
Pseudobulbar palsy is characterized by difficulties in facial expressions and speech.
Pseudobulbar palsy is characterized by difficulties in facial expressions and speech.
What role do T cells play in the pathophysiology of ADEM?
What role do T cells play in the pathophysiology of ADEM?
The mechanism by which pathogens resemble myelin is known as __________ mimicry.
The mechanism by which pathogens resemble myelin is known as __________ mimicry.
Which of the following is a primary feature of ADEM?
Which of the following is a primary feature of ADEM?
What is a common MRI finding in ADEM?
What is a common MRI finding in ADEM?
ADEM primarily affects white matter and spares gray matter.
ADEM primarily affects white matter and spares gray matter.
What treatment is considered the first-line for ADEM?
What treatment is considered the first-line for ADEM?
___ is indicated by decreased reflexes and flaccid weakness in ADEM.
___ is indicated by decreased reflexes and flaccid weakness in ADEM.
Match the following neurological tracts with their corresponding deficits:
Match the following neurological tracts with their corresponding deficits:
Which of the following symptoms can follow a viral or bacterial infection leading to ADEM?
Which of the following symptoms can follow a viral or bacterial infection leading to ADEM?
A lumbar puncture is performed to analyze cerebrospinal fluid (CSF) for signs of infection in ADEM.
A lumbar puncture is performed to analyze cerebrospinal fluid (CSF) for signs of infection in ADEM.
List one complication that must be monitored for in ADEM patients.
List one complication that must be monitored for in ADEM patients.
MRI T1 sequences typically show _____ lesions indicating demyelination.
MRI T1 sequences typically show _____ lesions indicating demyelination.
What indicates an ineffective response to corticosteroid treatment in ADEM?
What indicates an ineffective response to corticosteroid treatment in ADEM?
What are the primary neurological symptoms associated with ADEM?
What are the primary neurological symptoms associated with ADEM?
MRI T1 sequences typically show bright areas indicating demyelination.
MRI T1 sequences typically show bright areas indicating demyelination.
What is the first-line treatment for ADEM?
What is the first-line treatment for ADEM?
Demyelination in ADEM can affect both __________ and gray matter.
Demyelination in ADEM can affect both __________ and gray matter.
Match the following sensory deficits with their corresponding tracts:
Match the following sensory deficits with their corresponding tracts:
Which of the following findings in cerebrospinal fluid analysis might indicate a diagnosis of ADEM?
Which of the following findings in cerebrospinal fluid analysis might indicate a diagnosis of ADEM?
Hyporeflexia is a sign of upper motor neuron lesions.
Hyporeflexia is a sign of upper motor neuron lesions.
What is a common infectious trigger that may lead to ADEM?
What is a common infectious trigger that may lead to ADEM?
In ADEM, symptoms can occur following a __________ infection.
In ADEM, symptoms can occur following a __________ infection.
When diagnosing ADEM, what type of MRI findings are most commonly observed?
When diagnosing ADEM, what type of MRI findings are most commonly observed?
What type of infections are particularly noted as environmental triggers for ADEM?
What type of infections are particularly noted as environmental triggers for ADEM?
Acute disseminating encephalomyelitis (ADEM) primarily affects older adults.
Acute disseminating encephalomyelitis (ADEM) primarily affects older adults.
Name one cytokine that plays a role in the inflammatory response in ADEM.
Name one cytokine that plays a role in the inflammatory response in ADEM.
In ADEM, the process of mistakenly targeting myelin by T cells is known as __________ mimicry.
In ADEM, the process of mistakenly targeting myelin by T cells is known as __________ mimicry.
Match the following symptoms of ADEM with their descriptions:
Match the following symptoms of ADEM with their descriptions:
What is a common clinical feature of ADEM?
What is a common clinical feature of ADEM?
The damage caused by ADEM primarily leads to the formation of plaques in gray matter.
The damage caused by ADEM primarily leads to the formation of plaques in gray matter.
How do T cells become activated in ADEM?
How do T cells become activated in ADEM?
Cytokines increase _________ molecule expression on endothelial cells, enhancing inflammation.
Cytokines increase _________ molecule expression on endothelial cells, enhancing inflammation.
Which of the following is considered a potential genetic factor in ADEM?
Which of the following is considered a potential genetic factor in ADEM?
What mechanism allows T cells to mistakenly target myelin in ADEM?
What mechanism allows T cells to mistakenly target myelin in ADEM?
ADEM is more commonly seen in older adults than younger individuals.
ADEM is more commonly seen in older adults than younger individuals.
Name one environmental trigger that can lead to ADEM.
Name one environmental trigger that can lead to ADEM.
Cytokines increase cell adhesion molecule expression on _______ cells.
Cytokines increase cell adhesion molecule expression on _______ cells.
Match the clinical features of ADEM with their descriptions:
Match the clinical features of ADEM with their descriptions:
Which immune cells are primarily involved in the phagocytosis of oligodendrocytes during demyelination in ADEM?
Which immune cells are primarily involved in the phagocytosis of oligodendrocytes during demyelination in ADEM?
In ADEM, injury primarily occurs in white matter, but gray matter can also be affected.
In ADEM, injury primarily occurs in white matter, but gray matter can also be affected.
What role do cytokines play in the inflammatory response of ADEM?
What role do cytokines play in the inflammatory response of ADEM?
The inflammatory response in ADEM is primarily mediated by the release of _______ from activated T cells.
The inflammatory response in ADEM is primarily mediated by the release of _______ from activated T cells.
Which of the following cytokines is NOT typically involved in the inflammatory response of ADEM?
Which of the following cytokines is NOT typically involved in the inflammatory response of ADEM?
Which of the following symptoms is NOT typically associated with Acute Disseminated Encephalomyelitis (ADEM)?
Which of the following symptoms is NOT typically associated with Acute Disseminated Encephalomyelitis (ADEM)?
MRI T1 sequences show dark areas indicative of demyelination.
MRI T1 sequences show dark areas indicative of demyelination.
What is the first-line treatment used to manage inflammation in ADEM?
What is the first-line treatment used to manage inflammation in ADEM?
In ADEM, there is potential injury to the _____ gray horn.
In ADEM, there is potential injury to the _____ gray horn.
Match the neurological deficits with their corresponding affected tracts:
Match the neurological deficits with their corresponding affected tracts:
Which type of sensory deficit is typically linked to damage in the anterolateral tract?
Which type of sensory deficit is typically linked to damage in the anterolateral tract?
Plasmapheresis is used when corticosteroids are contraindicated or ineffective in ADEM treatment.
Plasmapheresis is used when corticosteroids are contraindicated or ineffective in ADEM treatment.
What diagnostic test can be performed to analyze cerebrospinal fluid for evidence of ADEM?
What diagnostic test can be performed to analyze cerebrospinal fluid for evidence of ADEM?
In ADEM, the presence of _____ antibodies in cerebrospinal fluid is indicative of oligoclonal banding.
In ADEM, the presence of _____ antibodies in cerebrospinal fluid is indicative of oligoclonal banding.
What is a common trigger that may precede the symptoms of ADEM?
What is a common trigger that may precede the symptoms of ADEM?
Study Notes
Etiology and Pathophysiology of ADEM
- Acute disseminating encephalomyelitis (ADEM) is considered an autoimmune disease, similar to multiple sclerosis but typically presents as an acute flare-up.
- Environmental triggers include viral infections, especially measles, mumps, rubella, or the MMR vaccine, and bacterial infections such as Mycoplasma pneumoniae and Streptococcus beta-hemolyticus.
- A genetic component may exist, with potential but undocumented susceptibility genes involved.
- ADEM is more common in younger individuals, often following viral infections or vaccinations.
Mechanism of Action
- Exposure to pathogens introduces antigens that are processed and presented to T cells by antigen-presenting cells, activating an immune response.
- T cells may mistakenly target myelin due to molecular mimicry, where protein components in pathogens resemble myelin basic proteins.
- Activated T cells cross the blood-brain barrier and trigger an inflammatory response through the release of cytokines (e.g., IL-1, IL-6, TNF-alpha, and interferon-gamma).
Inflammatory Response
- Cytokines increase cell adhesion molecule expression on endothelial cells, enhance vasodilation, and increase capillary permeability, allowing more immune cells to enter the affected area.
- White blood cells like macrophages are recruited, which exacerbate demyelination through phagocytosis of oligodendrocytes.
- Immune-mediated damage results in the formation of plaques in white matter and potential injury to gray matter.
Clinical Features of ADEM
- ADEM commonly presents as a single event in younger patients, with symptoms including:
- Fever and mild symptoms (headaches, nausea).
- Optic neuritis, causing decreased visual acuity and color vision abnormalities.
- Pseudobulbar palsy, affecting cranial nerves and causing:
- Altered facial expressions, dysarthria, dysphagia, and dysphonia.
- Patients may exhibit encephalopathy with an altered mental status, confusion, irritability, and in severe cases, coma.
- Ataxia can result from demyelination in the cerebellum and potential seizures from cortical neuron involvement.
Neurological Impact
- Damage to the spinal cord tracks can lead to specific deficits:
- Dorsal columns: Impaired proprioception, fine touch, and vibration sense.
- Corticospinal tracts: Signs of upper motor neuron lesions such as increased tone and hyperreflexia.
- Anterolateral tract: Decreased sensation of crude touch and pressure.
- Neuro deficits reflect extensive damage to both myelin and neuronal structures, distinguishing ADEM from conditions like multiple sclerosis.### Acute Disseminated Encephalomyelitis (ADEM) Overview
- ADEM can cause altered sensations, including decreased pressure sensation and decreased pain and temperature sensations.
- Demyelination can affect both axons and gray matter, potentially injuring the anterior gray horn.
- Injury to the anterior horn can result in lower motor neuron lesions, presenting with flaccid weakness and hypotonia.
Clinical Features
- Weakness is flaccid with decreased tone; patients exhibit hyporeflexia (decreased reflexes).
- Fasciculations may be present, indicated by small muscle twitches.
- Symptoms can follow a trigger such as a viral or bacterial infection, leading to acute weakness and altered mental status.
Diagnostic Approach
- First-line diagnostic test: MRI of the brain and spinal cord with and without contrast.
- MRI findings include multifocal and asymmetric demyelination, particularly in the supratentorial region (cerebral cortex, cerebellum, brainstem, spinal cord).
- MRI sequences:
- T1 typically shows hypo-intense lesions (dark areas indicate demyelination).
- T2 demonstrates hyper-intense lesions (bright areas indicate demyelination).
Additional Diagnostic Tests
- Lumbar puncture to analyze cerebrospinal fluid (CSF) for:
- Increased IgG antibodies indicative of oligoclonal banding.
- Pleocytosis, characterized by elevated white blood cells including B cells, T cells, and macrophages.
- Cultures may be performed to rule out infections like streptococcus beta-hemolyticus, mycoplasma, and viruses such as measles, mumps, and rubella.
Treatment Protocol
- High-dose intravenous corticosteroids are the first-line treatment; they reduce inflammation by inhibiting cytokine activity.
- If corticosteroids are ineffective or contraindicated, consider plasmapheresis to remove harmful antibodies and proteins.
- Intravenous immunoglobulin (IVIG) can also be used to bind to IgG antibodies, preventing their action on oligodendrocytes and myelin.
Infection Considerations
- High alert for possible meningitis or encephalitis due to overlapping symptoms.
- Empirically start antibiotics for bacterial infections and antivirals for possible viral infections until cultures confirm the absence of pathogens.
- Treatment should continue until results are available, at which point therapies can be adjusted.
Summary
- ADEM is a demyelinating condition that requires prompt diagnosis and treatment to mitigate inflammatory damage and address potential infectious complications.
ADEM Overview
- Acute disseminating encephalomyelitis (ADEM) is an autoimmune demyelinating disease, often an acute response.
- Associated with viral infections (measles, mumps, rubella) and bacterial infections (Mycoplasma pneumoniae, Streptococcus beta-hemolyticus).
- More prevalent in younger individuals, often following infections or vaccinations.
Mechanism of Action
- Pathogen exposure leads to antigen presentation to T cells, triggering an immune response.
- Molecular mimicry may cause T cells to target myelin, mistaking it for pathogen proteins.
- Activated T cells cross the blood-brain barrier, releasing cytokines that induce inflammation.
Inflammatory Response
- Cytokines enhance cell adhesion, vasodilation, and capillary permeability, allowing immune cells to infiltrate affected areas.
- Macrophages exacerbate demyelination by phagocytizing oligodendrocytes.
- Resultant damage creates plaques in white matter and can harm gray matter.
Clinical Features
- Presents as a single episode in younger patients, with symptoms like:
- Fever, headaches, nausea.
- Optic neuritis, affecting visual acuity and color vision.
- Pseudobulbar palsy, affecting facial expression and speech.
- Patients may present with altered mental status, ranging from confusion to coma.
- Ataxia and seizures are possible consequences of cerebellar demyelination.
Neurological Impact
- Damage to specific spinal cord tracks results in characteristic deficits:
- Impaired proprioception and fine touch due to dorsal column involvement.
- Upper motor neuron signs from corticospinal tract damage.
- Decreased sensation from anterolateral tract injury.
- Demyelination affects both myelin and neuronal structures, differing ADEM from multiple sclerosis.
Sensory Changes
- Patients may experience altered sensations including decreased pressure and temperature sensitivity.
- Anterior horn injury leads to lower motor neuron lesions, resulting in flaccid weakness and hypotonia.
Clinical Symptoms
- Flaccid weakness with reduced tone and hyporeflexia.
- Possible muscle fasciculations indicating active lower motor neuron involvement.
- Symptoms often arise following viral or bacterial triggers, resulting in acute weakness and confusion.
Diagnostic Approach
- MRI is the first-line diagnostic tool, revealing multifocal and asymmetric demyelination.
- MRI findings include:
- T1 sequences showing hypo-intense lesions.
- T2 sequences displaying hyper-intense lesions.
Additional Diagnostic Tests
- Lumbar puncture for cerebrospinal fluid (CSF) analysis indicates:
- Increased IgG antibodies suggesting oligoclonal bands.
- Pleocytosis with elevated white blood cells, including B cells, T cells, and macrophages.
- Cultures may rule out pathogens linked to symptoms.
Treatment Protocol
- High-dose intravenous corticosteroids are the primary treatment to reduce inflammation.
- If ineffective, plasmapheresis can remove antibodies and proteins.
- Intravenous immunoglobulin (IVIG) may block IgG antibody activity on oligodendrocytes.
Infection Considerations
- Monitor closely for signs of meningitis or encephalitis due to symptom overlap.
- Start empirical antibiotics for bacterial infections and antivirals for viral infections until testing is completed.
- Treatment adjustments occur after determining the presence or absence of pathogens.
Summary
- ADEM requires prompt diagnosis and treatment to limit inflammatory damage and address potential infections.
ADEM Overview
- Acute disseminating encephalomyelitis (ADEM) is an autoimmune demyelinating disease, often an acute response.
- Associated with viral infections (measles, mumps, rubella) and bacterial infections (Mycoplasma pneumoniae, Streptococcus beta-hemolyticus).
- More prevalent in younger individuals, often following infections or vaccinations.
Mechanism of Action
- Pathogen exposure leads to antigen presentation to T cells, triggering an immune response.
- Molecular mimicry may cause T cells to target myelin, mistaking it for pathogen proteins.
- Activated T cells cross the blood-brain barrier, releasing cytokines that induce inflammation.
Inflammatory Response
- Cytokines enhance cell adhesion, vasodilation, and capillary permeability, allowing immune cells to infiltrate affected areas.
- Macrophages exacerbate demyelination by phagocytizing oligodendrocytes.
- Resultant damage creates plaques in white matter and can harm gray matter.
Clinical Features
- Presents as a single episode in younger patients, with symptoms like:
- Fever, headaches, nausea.
- Optic neuritis, affecting visual acuity and color vision.
- Pseudobulbar palsy, affecting facial expression and speech.
- Patients may present with altered mental status, ranging from confusion to coma.
- Ataxia and seizures are possible consequences of cerebellar demyelination.
Neurological Impact
- Damage to specific spinal cord tracks results in characteristic deficits:
- Impaired proprioception and fine touch due to dorsal column involvement.
- Upper motor neuron signs from corticospinal tract damage.
- Decreased sensation from anterolateral tract injury.
- Demyelination affects both myelin and neuronal structures, differing ADEM from multiple sclerosis.
Sensory Changes
- Patients may experience altered sensations including decreased pressure and temperature sensitivity.
- Anterior horn injury leads to lower motor neuron lesions, resulting in flaccid weakness and hypotonia.
Clinical Symptoms
- Flaccid weakness with reduced tone and hyporeflexia.
- Possible muscle fasciculations indicating active lower motor neuron involvement.
- Symptoms often arise following viral or bacterial triggers, resulting in acute weakness and confusion.
Diagnostic Approach
- MRI is the first-line diagnostic tool, revealing multifocal and asymmetric demyelination.
- MRI findings include:
- T1 sequences showing hypo-intense lesions.
- T2 sequences displaying hyper-intense lesions.
Additional Diagnostic Tests
- Lumbar puncture for cerebrospinal fluid (CSF) analysis indicates:
- Increased IgG antibodies suggesting oligoclonal bands.
- Pleocytosis with elevated white blood cells, including B cells, T cells, and macrophages.
- Cultures may rule out pathogens linked to symptoms.
Treatment Protocol
- High-dose intravenous corticosteroids are the primary treatment to reduce inflammation.
- If ineffective, plasmapheresis can remove antibodies and proteins.
- Intravenous immunoglobulin (IVIG) may block IgG antibody activity on oligodendrocytes.
Infection Considerations
- Monitor closely for signs of meningitis or encephalitis due to symptom overlap.
- Start empirical antibiotics for bacterial infections and antivirals for viral infections until testing is completed.
- Treatment adjustments occur after determining the presence or absence of pathogens.
Summary
- ADEM requires prompt diagnosis and treatment to limit inflammatory damage and address potential infections.
ADEM Overview
- Acute disseminating encephalomyelitis (ADEM) is an autoimmune demyelinating disease, often an acute response.
- Associated with viral infections (measles, mumps, rubella) and bacterial infections (Mycoplasma pneumoniae, Streptococcus beta-hemolyticus).
- More prevalent in younger individuals, often following infections or vaccinations.
Mechanism of Action
- Pathogen exposure leads to antigen presentation to T cells, triggering an immune response.
- Molecular mimicry may cause T cells to target myelin, mistaking it for pathogen proteins.
- Activated T cells cross the blood-brain barrier, releasing cytokines that induce inflammation.
Inflammatory Response
- Cytokines enhance cell adhesion, vasodilation, and capillary permeability, allowing immune cells to infiltrate affected areas.
- Macrophages exacerbate demyelination by phagocytizing oligodendrocytes.
- Resultant damage creates plaques in white matter and can harm gray matter.
Clinical Features
- Presents as a single episode in younger patients, with symptoms like:
- Fever, headaches, nausea.
- Optic neuritis, affecting visual acuity and color vision.
- Pseudobulbar palsy, affecting facial expression and speech.
- Patients may present with altered mental status, ranging from confusion to coma.
- Ataxia and seizures are possible consequences of cerebellar demyelination.
Neurological Impact
- Damage to specific spinal cord tracks results in characteristic deficits:
- Impaired proprioception and fine touch due to dorsal column involvement.
- Upper motor neuron signs from corticospinal tract damage.
- Decreased sensation from anterolateral tract injury.
- Demyelination affects both myelin and neuronal structures, differing ADEM from multiple sclerosis.
Sensory Changes
- Patients may experience altered sensations including decreased pressure and temperature sensitivity.
- Anterior horn injury leads to lower motor neuron lesions, resulting in flaccid weakness and hypotonia.
Clinical Symptoms
- Flaccid weakness with reduced tone and hyporeflexia.
- Possible muscle fasciculations indicating active lower motor neuron involvement.
- Symptoms often arise following viral or bacterial triggers, resulting in acute weakness and confusion.
Diagnostic Approach
- MRI is the first-line diagnostic tool, revealing multifocal and asymmetric demyelination.
- MRI findings include:
- T1 sequences showing hypo-intense lesions.
- T2 sequences displaying hyper-intense lesions.
Additional Diagnostic Tests
- Lumbar puncture for cerebrospinal fluid (CSF) analysis indicates:
- Increased IgG antibodies suggesting oligoclonal bands.
- Pleocytosis with elevated white blood cells, including B cells, T cells, and macrophages.
- Cultures may rule out pathogens linked to symptoms.
Treatment Protocol
- High-dose intravenous corticosteroids are the primary treatment to reduce inflammation.
- If ineffective, plasmapheresis can remove antibodies and proteins.
- Intravenous immunoglobulin (IVIG) may block IgG antibody activity on oligodendrocytes.
Infection Considerations
- Monitor closely for signs of meningitis or encephalitis due to symptom overlap.
- Start empirical antibiotics for bacterial infections and antivirals for viral infections until testing is completed.
- Treatment adjustments occur after determining the presence or absence of pathogens.
Summary
- ADEM requires prompt diagnosis and treatment to limit inflammatory damage and address potential infections.
ADEM Overview
- Acute disseminating encephalomyelitis (ADEM) is an autoimmune demyelinating disease, often an acute response.
- Associated with viral infections (measles, mumps, rubella) and bacterial infections (Mycoplasma pneumoniae, Streptococcus beta-hemolyticus).
- More prevalent in younger individuals, often following infections or vaccinations.
Mechanism of Action
- Pathogen exposure leads to antigen presentation to T cells, triggering an immune response.
- Molecular mimicry may cause T cells to target myelin, mistaking it for pathogen proteins.
- Activated T cells cross the blood-brain barrier, releasing cytokines that induce inflammation.
Inflammatory Response
- Cytokines enhance cell adhesion, vasodilation, and capillary permeability, allowing immune cells to infiltrate affected areas.
- Macrophages exacerbate demyelination by phagocytizing oligodendrocytes.
- Resultant damage creates plaques in white matter and can harm gray matter.
Clinical Features
- Presents as a single episode in younger patients, with symptoms like:
- Fever, headaches, nausea.
- Optic neuritis, affecting visual acuity and color vision.
- Pseudobulbar palsy, affecting facial expression and speech.
- Patients may present with altered mental status, ranging from confusion to coma.
- Ataxia and seizures are possible consequences of cerebellar demyelination.
Neurological Impact
- Damage to specific spinal cord tracks results in characteristic deficits:
- Impaired proprioception and fine touch due to dorsal column involvement.
- Upper motor neuron signs from corticospinal tract damage.
- Decreased sensation from anterolateral tract injury.
- Demyelination affects both myelin and neuronal structures, differing ADEM from multiple sclerosis.
Sensory Changes
- Patients may experience altered sensations including decreased pressure and temperature sensitivity.
- Anterior horn injury leads to lower motor neuron lesions, resulting in flaccid weakness and hypotonia.
Clinical Symptoms
- Flaccid weakness with reduced tone and hyporeflexia.
- Possible muscle fasciculations indicating active lower motor neuron involvement.
- Symptoms often arise following viral or bacterial triggers, resulting in acute weakness and confusion.
Diagnostic Approach
- MRI is the first-line diagnostic tool, revealing multifocal and asymmetric demyelination.
- MRI findings include:
- T1 sequences showing hypo-intense lesions.
- T2 sequences displaying hyper-intense lesions.
Additional Diagnostic Tests
- Lumbar puncture for cerebrospinal fluid (CSF) analysis indicates:
- Increased IgG antibodies suggesting oligoclonal bands.
- Pleocytosis with elevated white blood cells, including B cells, T cells, and macrophages.
- Cultures may rule out pathogens linked to symptoms.
Treatment Protocol
- High-dose intravenous corticosteroids are the primary treatment to reduce inflammation.
- If ineffective, plasmapheresis can remove antibodies and proteins.
- Intravenous immunoglobulin (IVIG) may block IgG antibody activity on oligodendrocytes.
Infection Considerations
- Monitor closely for signs of meningitis or encephalitis due to symptom overlap.
- Start empirical antibiotics for bacterial infections and antivirals for viral infections until testing is completed.
- Treatment adjustments occur after determining the presence or absence of pathogens.
Summary
- ADEM requires prompt diagnosis and treatment to limit inflammatory damage and address potential infections.
ADEM Overview
- Acute disseminating encephalomyelitis (ADEM) is an autoimmune demyelinating disease, often an acute response.
- Associated with viral infections (measles, mumps, rubella) and bacterial infections (Mycoplasma pneumoniae, Streptococcus beta-hemolyticus).
- More prevalent in younger individuals, often following infections or vaccinations.
Mechanism of Action
- Pathogen exposure leads to antigen presentation to T cells, triggering an immune response.
- Molecular mimicry may cause T cells to target myelin, mistaking it for pathogen proteins.
- Activated T cells cross the blood-brain barrier, releasing cytokines that induce inflammation.
Inflammatory Response
- Cytokines enhance cell adhesion, vasodilation, and capillary permeability, allowing immune cells to infiltrate affected areas.
- Macrophages exacerbate demyelination by phagocytizing oligodendrocytes.
- Resultant damage creates plaques in white matter and can harm gray matter.
Clinical Features
- Presents as a single episode in younger patients, with symptoms like:
- Fever, headaches, nausea.
- Optic neuritis, affecting visual acuity and color vision.
- Pseudobulbar palsy, affecting facial expression and speech.
- Patients may present with altered mental status, ranging from confusion to coma.
- Ataxia and seizures are possible consequences of cerebellar demyelination.
Neurological Impact
- Damage to specific spinal cord tracks results in characteristic deficits:
- Impaired proprioception and fine touch due to dorsal column involvement.
- Upper motor neuron signs from corticospinal tract damage.
- Decreased sensation from anterolateral tract injury.
- Demyelination affects both myelin and neuronal structures, differing ADEM from multiple sclerosis.
Sensory Changes
- Patients may experience altered sensations including decreased pressure and temperature sensitivity.
- Anterior horn injury leads to lower motor neuron lesions, resulting in flaccid weakness and hypotonia.
Clinical Symptoms
- Flaccid weakness with reduced tone and hyporeflexia.
- Possible muscle fasciculations indicating active lower motor neuron involvement.
- Symptoms often arise following viral or bacterial triggers, resulting in acute weakness and confusion.
Diagnostic Approach
- MRI is the first-line diagnostic tool, revealing multifocal and asymmetric demyelination.
- MRI findings include:
- T1 sequences showing hypo-intense lesions.
- T2 sequences displaying hyper-intense lesions.
Additional Diagnostic Tests
- Lumbar puncture for cerebrospinal fluid (CSF) analysis indicates:
- Increased IgG antibodies suggesting oligoclonal bands.
- Pleocytosis with elevated white blood cells, including B cells, T cells, and macrophages.
- Cultures may rule out pathogens linked to symptoms.
Treatment Protocol
- High-dose intravenous corticosteroids are the primary treatment to reduce inflammation.
- If ineffective, plasmapheresis can remove antibodies and proteins.
- Intravenous immunoglobulin (IVIG) may block IgG antibody activity on oligodendrocytes.
Infection Considerations
- Monitor closely for signs of meningitis or encephalitis due to symptom overlap.
- Start empirical antibiotics for bacterial infections and antivirals for viral infections until testing is completed.
- Treatment adjustments occur after determining the presence or absence of pathogens.
Summary
- ADEM requires prompt diagnosis and treatment to limit inflammatory damage and address potential infections.
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Description
This quiz explores the etiology and pathophysiology of Acute Disseminating Encephalomyelitis (ADEM). It covers the autoimmune aspects, environmental triggers, and the immune response mechanisms involved in ADEM. Understanding these factors is crucial for grasping the complexity of this condition.
