Adem

Acute Disseminated Encephalomyelitis
Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Fever, headache, nausea, vomiting, seizures, ataxia, vision problems, weakness
Complications	Neurological deficits, relapse
Onset	Rapid
Duration	Weeks to months
Types	N/A
Causes	Often follows viral infection or vaccination
Risks	Recent infection, immunization
Diagnosis	MRI, lumbar puncture
Differential diagnosis	N/A
Prevention	N/A
Treatment	Corticosteroids, plasmapheresis, intravenous immunoglobulin
Medication	N/A
Prognosis	Generally good with treatment
Frequency	Rare
Deaths	N/A

Acute Disseminated Encephalomyelitis (ADEM) is a rare, inflammatory, demyelinating disease of the central nervous system (CNS) that predominantly affects the brain and spinal cord. It is characterized by a brief but widespread attack of inflammation in the brain and spinal cord, damaging the myelin, the protective covering of nerve fibers.

Pathophysiology

ADEM is considered an autoimmune disease, where the body's immune system mistakenly attacks its own tissues. The exact mechanism is not fully understood, but it is believed to involve an immune response triggered by an infection or vaccination. This response leads to inflammation and demyelination in the CNS.

The myelin sheath, which insulates nerve fibers, is damaged, leading to disrupted nerve signal transmission. This results in the neurological symptoms associated with ADEM.

Causes

ADEM often follows a viral infection or, less commonly, a bacterial infection. It can also occur after vaccination, although this is rare. Common infections that precede ADEM include measles, mumps, rubella, influenza, and Epstein-Barr virus.

Symptoms

Symptoms of ADEM typically appear rapidly and can include:

• Fever
• Headache
• Nausea and vomiting
• Seizures
• Ataxia (lack of voluntary coordination of muscle movements)
• Vision problems
• Weakness or paralysis
• Altered mental status

Diagnosis

Diagnosis of ADEM is based on clinical presentation and imaging studies. Magnetic Resonance Imaging (MRI) is the most useful tool, showing characteristic lesions in the white matter of the brain and spinal cord. A lumbar puncture may be performed to analyze cerebrospinal fluid (CSF) for signs of inflammation.

Treatment

The primary treatment for ADEM is high-dose corticosteroids, such as methylprednisolone, to reduce inflammation. If patients do not respond to steroids, other treatments such as plasmapheresis or intravenous immunoglobulin (IVIG) may be used.

Prognosis

The prognosis for ADEM is generally good, with most patients recovering fully or with minor residual deficits. However, some patients may experience relapses or develop multiple sclerosis.

Epidemiology

ADEM is a rare condition, with an estimated incidence of 0.4 to 0.8 per 100,000 people per year. It is more common in children than adults and has a slight male predominance.

See also

• Multiple sclerosis
• Neuromyelitis optica
• Guillain-Barré syndrome