Table 35.3.
Features of the major central nervous system demyelinating diseases
| NMO | Multiple sclerosis | ADEM | |
|---|---|---|---|
| Demographics | |||
| Age of onset (median) in years | 40 | 30 | 6.5 (pediatric); 33 (adults)† |
| Sex F:M | 8:1 (relapsing) | 2:1 (relapsing) | 1:1 |
| Ethnicity | ↑ Incidence in non-white | Usually white | All populations at risk |
| Clinical course | |||
| Monophasic | 20% | NA | > 95% |
| Relapsing | 80% | 85% initially | < 5% |
| Primary progressive | NA | 15% | NA |
| MRI features | |||
| Brain white-matter lesions | Typically absent at onset | Oval, usually perpendicular to ventricles | Large, disseminated; rarely periventricular |
| Spinal cord lesions | Longitudinally extensive | Punctate | Punctate to rarely large longitudinal |
| Optic nerve lesions | Unilateral or bilateral, with poor recovery | Usually unilateral, with good recovery | Unilateral or bilateral with good recovery |
| CSF findings | |||
| WBC count | ↑↑↑ Lymphocytes, neutrophils | ↑ Lymphocytes | ↑↑ Lymphocytes, occasionally neutrophils |
| Total protein | Elevated | Typically normal | Normal to elevated |
| Oligoclonal bands (OCBs) | Typically absent* | > 90% present | Variable (0–29%)‡ |
| Pathology | |||
| Gray matter | Demyelination with necrosis | Demyelination | Demyelination (AHL : hemorrhage) |
| White matter | Demyelination with necrosis | Demyelination | Demyelination (AHL : hemorrhage) |
| Lesion immunopathology | |||
| Macrophages | +++ | +++ | +++ |
| T cells | +/– | +++ | +++ |
| Eosinophils | ++ | None | Rare |
| Neutrophils | +++ | None | Occasional |
| Antibodies | +++ | Variable | Variable |
| Complement | ++ | Variable | Variable |
| Coexisting autoimmune diseases | 30–50% | Infrequent | Not seen |
| Disability progression | Relapse-related | Independent of relapses | Relapse-related in recurrent/multifocal |
NMO, neuromyelitis optica; ADEM, acute disseminated encephalomyelitis; MRI, magnetic resonance imaging; CSF, cerebrospinal fluid; WBC, white blood cell; AHL, acute hemorrhagic leukoencephalopathy.
*
OCBs may be seen during active disease, but disappear during remission. In ADEM, persistence of OCBs during disease remission raises suspicion for later risk of developing multiple sclerosis.