White matter disease

Disease modifying treatment available:
Time critical diagnosis and management:
Lateralising:

Definition

The term white matter disease is used collectively to refer to disorders which cause disruption to the white matter of the brain.

Disorders of the white matter are often identified on MRI of the brain.

Taxotomy

Subclassifications	Epidemiology	Clinical features
Leukodystrophy	None

Aetiology

Primary progressive MS is more common than the leukodystrophies but can be missed.

Disorder	Clinical features	Associated features	Investigations	Disease modifying treatment available	Time critical
Multiple sclerosis	Myelitis Longitudinally extensive myelitis Sensorineural hearing loss	Psoriasis Hashimoto's thyroiditis Insomnia
Cerebral small vessel disease

Clinical features

None

Investigations

First line investigations should include blood tests for HIV, syphilis, hepatitis B, hepatitis C, vasculitis screen and autoimmune screen. First line imaging includes MRI of the brain and spine with contrast. Lumbar puncture should include routine constituents, oligoclonal bands (paired with serum), cytology and JC virus serology. Second line investigations are focused on eliciting a metabolic cause. Blood tests include very long chain fatty acids, white cell enzymes (galactocerebrosidase and arylsulfatase A), plasma amino acid profile, total homocysteine, plasma sterols and pituitary function tests. Urine should be sent for bile alcohols. Third line investigations include genetic testing, imaging sensitive for calcium (such as CT) and iron (susceptibility weighted MRI), ophthalmology review with slit lamp examination, neurophysiology and biopsy of nerve, muscle or brain.