XV. 탈수초성 질환(Demyelinating disease)

목차

I. 총론

II. 다발성 경화증(Multiple sclerosis)

III. 시 신경염(Optic neuritis)

IV. 급성 횡단성 척수염(Acute transverse myelitis)

V.급성 파종성 뇌척수염(Acute disseminated encephalomyelitis)

I. 총론

1. Myelin

Proteolipid membrane that ensheathes and surrounds nerve axons to conduct nerve action potential

Myelin producing cell: oligodenrocyte

Loss of myelin(demyelination) make it impossible to conduct action potential

2. Disease of CNS myelin

1) Idiopathic(autoimmune?)

Multiple sclerosis: recurrent or progressive

Monophasic demyelination

Optic neuritis

Transverse myelitis

Acute disseminated encephalomyelitis

2) Inherited metabolic

Restricted to central myelin

Adrenaloleukodystrophy

Alexander's disease

Pelizaeus-Merzbacher disease

Central and peripheral myelin

Metachromic leukodystrophy

Krabbe's globoid cell leukodystrophy

3) Infectious

Progressive multifocal leukoencephalopathy

Subacute sclerosing panencephalitis

HIV, HTLV-1 associated myelopathy

II. 다발성 경화증(Multiple sclerosis)

1. 정의

Chronic disease with multiple areas of CNS white matter inflammation, demyelination, and glial scarring(sclerosis)

Most patients begin with relapsing and remitting symptoms

Table 1. Initial sx of MS Table 2. Sx not suggesting MS

-> Lesions are multiple in time and space

2. 원인

Unknown

Genetic susceptibility + environmental factor with autoimmune mechanism

3. 임상 양상

1) epidemiology

Age: peak at 20-30 years(usually 10-60 years)

Incidence: female>male(1.4-3.1:1)

High prevalence area: northern Europe, northern US, Canada(30/100,000)

Low prevalence area: Japan, China, South America(5/100,000)

Associated with latitude(high latitude-incidence↑)

2) 증상과 징후- table 1.2참조

Symptom

Onset before age 10years or after age 55years

Prominent early dementia

Aphasia

Impaired consciousness

Seizures

Nonscotomatous visual field defect

Uveitis

Extrapyramidal findings

Fasiculation

3) 임상 경과

A: relapsing-remitting

B: relapsing-remitting

C: secondary-progressive

D: secondary-progressive

E: primary-progressive

F: primary-progressive

G: progressive-relapsing

Figure 1. example of MRI in MS

4. 검사

No pathogonomic test for MS

1) MRI

Most helpful(multiple white matter lesions in 90% of patient), but not specific

2) 뇌척수액 검사

Mild lymphocytic pleocytosis(5-20 cells/mm³), slightly increased protein in 50%

Increased IgG synthesis in 70%

Oligoclonal band (+) in 90%

Myelin basic protein

3) 유발 전위 검사(Evoked potential)

Great value in demonstrating clinically unsuspected lesions

: Visual evoked potential, Brainstem auditory evoked potential, Somatosensory evoked potential

Figure 2. example of VEP

5. MS in Korean people

Optico-spinal form(Devic's syndrome) MS ↑

6. 치료

Solumedrol pulse: acute stage of disease attack

Interferon beta: lesion burden, attak rate and severity↓

III. 시 신경염(Optic neuritis)

1. 임상 양상

Abrupt(usually over 2-3 days) loss of vision d/t optic nerve demyelination

Eyeball pain, papillitis, loss of color vision(achromatopsia)

2. 감별 진단: numerous condition may resemble optic neuritis

Ischemic optic neuropathy: sudden onset, old age, painless

Compressive lesion: slow progressive

Leber's hereditary optic atrophy: abrupt, progressive, bilateral visual loss in young age

Drug induced(e.g. methyl alcohol), nutritional

3. Relationship with MS

Initial sx of MS in approximately 17% of patient

Risk of developing MS: 30-60%

Risk factor of developing MS: abnormal cranial MRI, female, age<40, oligoclonal band

IV. 급성 횡단성 척수염(Acute transverse myelitis)

1. 원인

Idiopathic, postvaccinial, postinfectious, HIV, SLE, syphilis, etc

2. 임상 양상

Acute-subacute onset motor/sensory/sphincter dysfunction

Should exclude compressive lesion of spinal cord

3. Relationship between idiopathic transverse myelitis and MS

Initial sx of MS in less than 5% of patient( in Korea ↑?)

Risk of developing MS: less than 10%

V. 급성 파종성 뇌척수염(Acute disseminated encephalomyelitis)

1. 원인

Post-infectious(after 4-6days): measles, rubella, mumps, varicella, influenza, etc

Post-vaccinial(after 10-14days): measles, mumps, rubella, influenza, rabies

2. 병태 생리

Virus may trigger immune-mediated reaction against CNS myelin

Similar to experimental allergic encephalomyelitis

3. 임상 양상

Any portion of CNS may be affected-> variable clinical syndrome

Meningeal involvement: headache, neck stiffness

Encephalitic form: coma, convulsion, hemiplegia, aphasia

Cranial nerve palsy: esp, optic neuritis

Acute cerebellar ataxia

Acute transverse myelopathy