White matter disease, or leukoaraiosis, involves the degeneration of white matter in the brain. White matter is tissue that includes nerve fibers (axons), which connect nerve cells.
A fatty tissue called myelin covers the axons. These axons connect the neurons of the brain and spinal cord and signal nerve cells to communicate with one another.
Degeneration of the white matter — specifically, the myelin sheaths — can affect a person’s mood, focus, muscle strength, vision, and balance.
White matter disease may develop with conditions associated with aging, such as stroke, but it can also affect young people due to conditions such as cerebral adrenoleukodystrophy and multiple sclerosis (MS).
Read on to learn more about white matter disease and its symptoms, causes, and prognosis.
White matter disease includes many different conditions. It can be progressive, and people who develop this form of white matter disease will notice their symptoms become more pronounced as time goes on.
The life expectancy of a person with white matter disease depends on many factors, including the specific type, the rate at which it progresses, and the complications it causes.
White matter plays an essential role in communication within the brain and between the brain and spinal cord. As a result, damage to this tissue can lead to issues with:
- memory and focus
In the beginning stages of progressive white matter disease, the symptoms may be mild. As time passes, however, the symptoms may get worse.
- chronic hypertension
- high cholesterol
- history of stroke
- inflammation of the blood vessels
- Parkinson’s disease
One 2014 study suggests that unexplained white matter disease may be the result of damage due to small silent strokes.
A silent stroke is so small that it occurs without any symptoms. This means that the person does not usually know that they have had a stroke.
This study suggests that repeated silent strokes could lead to white matter disease.
There are several conditions that healthcare professionals consider to be white matter diseases. The common factors are impairment of normal myelination or damage to already myelinated nerves. Myelin is a layer of insulation that protects nerves in the brain and spinal cord, and myelination is the formation of this insulation layer.
Conditions affecting myelin can result from either destruction of existing myelin (demyelinating diseases) or from abnormalities in the formation of myelin (dysmyelinating diseases).
Processes that cause these types of damage include genetic conditions, autoimmune conditions, and infections.
Some examples of conditions that affect white matter include:
- Lyme disease
- Balo concentric sclerosis
- tumefactive demyelinating lesions
- Marburg and Schilder variants
- neuromyelitis optica, or Devic’s disease
- acute disseminated encephalomyelitis
- acute hemorrhagic leukoencephalopathy, or Hurst disease
- progressive multifocal leukoencephalopathy
- cerebral adrenoleukodystrophy
Different types of white matter disease may have different stages. For example, there are a few types of MS, and each differs in how it progresses.
At present, there is no universal staging system for the various forms of white matter disease.
That said, some researchers have proposed a staging procedure for white matter lesions, which they suggest would help healthcare professionals classify people into stages of white matter disease.
Doctors try to treat the underlying cause of the myelin condition in order to slow down or stop disease progression.
For many people with white matter disease due to small strokes, treatment options can include improving their cardiovascular health by eating a healthful diet, avoiding tobacco use, and taking medications for hypertension or high cholesterol.
Specific forms of white matter disease, such as MS or progressive multifocal leukoencephalopathy, may require other treatments.
Those who have issues with balance and walking as a result of white matter disease may need physical therapy.
A physical therapist can provide exercises and other techniques to improve balance and gait. They may also recommend using walking aids and other tools to prevent falls.
Some forms of white matter disease, such as dysmyelinating diseases, can begin during childhood.
Dysmyelinating diseases, wherein myelin does not form correctly, can result from problems such as an inherited enzyme deficiency.
Some examples in children include:
Late infantile metachromatic leukodystrophy
This condition occurs between 12 and 18 months of age and causes deterioration in thinking skills, speech, and coordination.
Within 2 years, children can develop gait and posture problems, as well as blindness and paralysis. It is not possible to stop disease progression, and it is typically fatal within 6 months to 4 years of symptom onset.
People with the juvenile form of metachromatic leukodystrophy, which develops between the age of 4 and adolescence, may live for many years after diagnosis.
Also known as globoid cell leukodystrophy, Krabbe disease can develop at any age. However, the most common form is infantile Krabbe disease, which begins before the age of 1.
In infants, it causes extreme irritability, increased muscle tone, fever, and developmental regression. The condition progresses rapidly and is fatal, usually by the age of 2.
This syndrome is characterized by liver dysfunction, jaundice, intellectual difficulties, and low muscle tone.
The severity of this condition varies. It can lead to early childhood death.
Infants and children with Leigh disease typically have low muscle tone and noticeably slow speech, physical reactions, and emotional reactions.
It also causes ataxia, or a loss of coordination of muscle movements, and problems swallowing.
Vanishing white matter disease
This is a rare inherited condition that can develop during childhood. It is characterized by early childhood onset of chronic neurological deterioration.
There are several forms of white matter disease. Each involves problems related to myelin, a fat that covers nerve fibers in the brain.
The most common forms of white matter disease relate to aging. It may result from small silent strokes, often with the presence of cardiovascular disease.
Less commonly, other forms of white matter disease affect children and younger adults.