Dejerine-Sottas disease

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at November 14, 2016
StartDiseasesDejerine-Sottas disease

Dejerine-Sottas disease is a very rare neurological disorder that causes a variety of issues and can progress very rapidly. Though there is no cure for this condition yet, but it is still possible for people with Dejerine-Sottas disease to lead a full life.

Contents

Definition & Facts

Dejerine-Sottas disease is a condition that affects the nerves of the body. It causes the nerves that are used for mobility to slowly deteriorate. For some undiscovered reason, the protective coating around nerves, called myelin, breaks down.

Nerves become enlarged and inflamed until they cannot work properly. This means that a patient cannot use their muscles properly anymore, so their muscles tend to waste away. Over time, patients with Dejerine-Sottas disease tend to lose some functions. 

Symptoms & Complaints

Dejerine-Sottas disease is hereditary, so patients will actually have it from birth. However, symptoms normally are not even noticeable until patients are around three. At first it progresses slowly, but it tends to accelerate around puberty.

Children with Dejerine-Sottas disease tend to have difficulty using motor skills. Many people are not diagnosed until around the age of 10 or 30 because Dejerine-Sottas disease symptoms are so mild at first. The symptoms start with a feeling of burning, tingling, or prickling in the muscles along the backs of legs. This feeling increases and spreads through the rest of the legs.

Patients slowly lose sensitivity and no longer have reflex actions in their legs. They experience extreme weakness and start to have trouble walking. This results in reduced muscle tone, and patients often end up needing wheelchairs or other walking devices. As Dejerine-Sottas disease progresses, it spreads to the arms, hands, and torso.

The reduced muscle tone can cause problems in skeletal function, so some end up with clubbed feet, clawed hands, and curved spines. In rare cases, Dejerine-Sottas disease can also cause eye problems and hearing problems because it interferes with the tiny nerves and muscles used to operate these sensory organs.

Causes

The cause of Dejerine-Sottas disease is genetic mutations that are inherited from parents. Several different genes can be responsible for making patients lose the myelin coating around their nerves. In some cases, it is a dominant gene that causes a parent to have a 50 percent chance of passing on Dejerine-Sottas disease to their offspring.

In other instances, Dejerine-Sottas disease can be a recessive gene that is transmitted in families for generations without actually resulting in Dejerine-Sottas disease. The gene mutations that cause Dejerine-Sottas disease can occur in either the PMP22, PRX, MPZ, or EGRS genes. These are all genes that affect the formation and function of the proteins that make up nerves and myelin sheaths.

Mutations may make it difficult for the myelin sheaths to properly protect the nerves of patients with Dejerine-Sottas disease. However, researchers still are not sure of the precise mechanisms that cause myelin sheaths to degrade over time. Until more research is done, it is difficult to even begin developing medications that may be able to stop this process. 

Diagnosis & Tests

The first step in being diagnosed with Dejerine-Sottas disease is generally visiting the doctor after a patient notices persistent weakness or a lack of sensation. After ruling out more common causes, doctors will generally begin to suspect that the patient is dealing with some sort of neurological disorder.

Since it is hereditary, a family history of Dejerine-Sottas disease and the symptoms of the disorder are often enough to diagnose it. However, a diagnosis is not always quick if a patient has inherited a recessive gene responsible for Dejerine-Sottas disease. Patients with Dejerine-Sottas disease may be misdiagnosed with muscular dystrophy, Charcot-Marie-Tooth disease, or one of the many other nervous system disorders. More detailed tests are normally needed to confirm that a patient is actually suffering from Dejerine-Sottas disease and not another related condition.

Imaging studies can be used to examine the nerves that are having issues. The nerves in the extremities and the cranial nerves often have a very distinctive "onion bulb" appearance. This occurs when the connective tissue around the nerves becomes enlarged due to the Dejerine-Sottas disease.

Treatment & Therapy

Most treatments for Dejerine-Sottas disease focus on improving the patient's quality of life. It is currently considered to be incurable, so there are no known ways of slowing or stopping the progression of Dejerine-Sottas disease. The condition tends to impair mobility, so a lot of therapies for patients focus on improving their ability to move around and complete daily tasks.

Braces that stabilize malformed joints can be very helpful if a patient has an increased risk of dislocations or bone fractures. At later stages, patients may need wheelchairs or other walking devices. If joints are malformed but the patient is otherwise healthy, surgery may be recommended for people with this condition. Surgeries can correct issues in the spine or feet that are causing pain for patients. Both over-the-counter painkillers and prescription pain medications may be needed to treat the pain that some patients with Dejerine-Sottas disease experience.

If a patient is suffering from hearing loss due to the condition, hearing aids can provide more hearing range for a person. Though eyeglasses provide some benefits for Dejerine-Sottas disease with vision loss, they may need surgery to correct nystagmus or other related vision problems.

Prevention & Prophylaxis

It can be difficult to prevent Dejerine-Sottas disease because it is genetic. The only available option for parents who are concerned about passing on Dejerine-Sottas disease genes is speaking with a genetic counselor. It may be possible for them to lower their risks of giving birth to a child with Dejerine-Sottas disease.

Patients should avoid excessive alcohol use and certain medications like the chemotherapeutic agent, vincristine because these substances can cause deterioration to accelerate.