Introduction
Adrenoleukodystrophy is a genetic neurodegenerative condition caused by mutations (changes) in the ABCD1 gene. Males and females are the majorly affected asymptomatic carriers. Restless leg syndrome is a condition in which there is a sudden intense urge to move limbs. It has genetic causes along with other causes.
What Is Adrenoleukodystrophy?
Adrenoleukodystrophy is a genetic disorder affecting the adrenal glands on the top of the kidneys and the nervous system. A fatty covering called myelin that insulates the brain nerves, and spinal cord tends to degenerate in this disorder called demyelination. This loss of myelin lowers the ability of the nerves to relay information to the brain. Also, the damage to the adrenal cortex (the outer layer of the adrenal glands) causes a shortage of certain hormones resulting in adrenocortical insufficiency. This adrenocortical insufficiency can cause weight loss, weakness, changes in the skin, vomiting, and coma.
The most common type of adrenoleukodystrophy is X-linked adrenoleukodystrophy which is caused due to a genetic defect on the X chromosome. It affects males more severely than females. The types of X-linked adrenoleukodystrophy include:
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Childhood Cerebral Form - The childhood cerebral type of adrenoleukodystrophy generally occurs in boys and rarely affects girls. If left untreated, boys between the ages of four to ten begin to experience learning and behavioral problems. With time, the symptoms worsen, and children may experience difficulty in writing, reading, comprehending written material, and understanding speech. Other symptoms include vision problems, difficulty swallowing, aggressive behavior, impaired adrenal gland function, and poor coordination.
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Adrenomyeloneuropathy - The symptoms of the adrenomyeloneuropathy type begin to appear between early childhood and middle age. Affected individuals experience progressive weakness and stiffness in the legs, urinary and genital tract disorders, and also changes in intellectual and behavioral function. Individuals with this adrenoleukodystrophy have adrenal insufficiency also.
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Adrenal Insufficiency Only Form - Individuals affected by X-linked adrenoleukodystrophy whose only sign is adrenal insufficiency is said to have adrenal insufficiency only form. In such individuals, it can begin between the first year of life and adulthood. The life expectancy of people with this type depends on the severity of the signs and symptoms. However, this type is the mildest of all types.
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Asymptomatic - Some children do not show any symptoms of adrenoleukodystrophy, but diagnostic tests show brain or biochemical abnormalities. Some people with asymptomatic adrenoleukodystrophy develop other types of X-linked adrenoleukodystrophy in later stages of life.
In adrenoleukodystrophy, the body cannot break down the long-chain fatty acids (VLFCAs), resulting in the build of saturated VLFCAs in the brain, nervous system, and adrenal glands. This disorder can be diagnosed through blood tests, vision screening (measuring visual responses to monitor disease progression), MRI (magnetic resonance imaging) scans and skin biopsy, and fibroblast cell culture (to check increased levels of VLCFAs).
This disorder has no cure, but the disease progression can be managed by various treatment options such as stem cell transplant, treating adrenal insufficiency with steroids, medications to relieve seizures and stiffness, and physical therapy to reduce muscle spasms and rigidity.
What Is Restless Leg Syndrome?
Restless leg syndrome, also known as Willis-Ekbom disease, is a sleep disorder that causes an irresistible intense urge to move the legs. It often occurs with other bodily sensations creeping, pulling, throbbing, itching, aching, crawling, or burning. Restless leg syndrome is found to be a genetic syndrome in some cases. Other causes include iron deficiency, hypothyroidism (the thyroid gland does not produce enough thyroid hormone), depression, kidney disease, uremia, Parkinson’s disease, fibromyalgia, and diabetes.
Medications such as antidepressants, anti-nausea medicines, and allergy drugs should be avoided as they lead to the development of restless leg syndrome. Other substances like nicotine, alcohol, and caffeine could worsen symptoms.
The symptoms of restless leg syndrome include:
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Leg discomfort due to uncomfortable limb sensations.
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Intense urge to move legs.
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Sleep disruptions.
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Behavioral (moodiness, irritability, hyperactivity, and difficulty concentrating) and work performance problems.
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Daytime sleepiness.
There are no specific diagnostic tests to diagnose restless leg syndrome. The diagnosis is based on the symptoms experienced by a person. Also, the treatment is based on the intensity of the symptoms. Treatment is generally considered if the quality of life is affected by lack of sleep (insomnia) and excessive daytime drowsiness.
First, non-drug treatments such as regular exercise, good sleeping habits, abiding caffeine and medications, applying a cold compress or heating pads to legs, reducing stress through yoga or medication, and soaking legs in a warm water tub are tried if the symptoms are mild. If iron deficiency is the cause of the syndrome, then iron supplements are recommended. If the symptoms are severe or frequent, medications such as Dopamine agonists, benzodiazepines, anti-seizure medications, and opioids are prescribed by the doctor.
Can People With Adrenoleukodystrophy Have Restless Legs Syndrome?
A study was conducted recently to investigate the prevalence of restless leg syndrome in people with X-linked adrenoleukodystrophy. The researchers observed that women are more often affected by movement disorders independent of demyelinating disease seen in men. This pilot study found that 40 percent of adults with adrenoleukodystrophy had restless leg syndrome, with females more commonly affected than men. This was higher than the general population, with a five to ten percent prevalence.
People with restless leg syndrome had more signs and symptoms of myelopathy (injury causing spinal cord compression), suggesting that the pathologic effects of adrenoleukodystrophy on spinal pathways can cause the development of restless leg syndrome. But they did not have signs of brain demyelination seen in adrenoleukodystrophy. The study suggested a high prevalence of restless leg syndrome in adults with adrenoleukodystrophy which can contribute to poor quality of life and sleep problems. Sleep disturbances associated with the restless syndrome may have functional consequences and worsen the manifestations of myelopathy in adrenoleukodystrophy.
Conclusion
The pilot study concluded a high prevalence of restless leg syndrome in people with adrenoleukodystrophy. Awareness of restless leg syndrome in people with adrenoleukodystrophy would allow for effective treatment, which can improve the functional impairments along with the quality of life, mood, and anxiety issues in people with adrenoleukodystrophy.
