Introduction
Neuropathy occurs when these nerves are damaged or destroyed and do not function properly. They may send out pain signals for no reason or may not send out signals when damaged. The job of the nerves is to send signals to the brain about bodily sensations. It also ensures that the body's internal functions, such as blood circulation and food digestion, function normally.
The peripheral nervous system sends information from the spinal cord and brain (central nervous system) to the rest of the body. Peripheral nerves send sensory information to the central nervous system. Peripheral neuropathy can be caused by trauma, metabolic problems, infection, genetic causes, and exposure to toxins. One of the most common causes is diabetes.
People with peripheral neuropathy usually describe the pain as burning, stabbing, or tingling. Symptoms often improve, especially if the cause is a treatable condition. Medication can reduce the pain of peripheral neuropathy.
What Is Congenital Hypomyelinating Neuropathy?
Hypomyelination means that the body cannot produce normal myelin (the protective layer on the surface of nerves, brain, and spinal cord). This inhibits the body from myelination of the brain and possibly even nerves outside the brain. This condition also reduces the size and function of the basal ganglia and cerebellum. Congenital dysmyelination neuropathy (CHN) is a rare congenital neuropathy characterized by nonprogressive muscle weakness, areflexia (absence of deep tendon reflex), hypotonia (decreased muscle tone), decreased nerve conduction velocity, and possibly hypomyelination (the body is unable to produce myelin at normal rate) in patients, that is usually present in infancy, and they may die within the first few years of life, usually after infectious complications. In infancy, it develops later, and patients live for several years.
What Is the Cause of Congenital Hypomyelinating Neuropathy?
Congenital hypomyelinating neuropathy is a genetically inherited condition. Mutations in contactin-associated protein 1 (CNTNAP1) were recently reported as a cause of congenital dysmyelination neuropathy. Severe hypotonia (loss of muscle tone), multiple distal joint contractures, and high mortality in the first few months of life characterize CNTNAP1-associated congenital dysmyelination neuropathy.
Who Is at Risk of Congenital Hypomyelinating Neuropathy?
The risk factors for congenital hypomyelinating neuropathy are listed below:
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Vitamin deficiencies, particularly B vitamins, in parents.
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Autoimmune diseases in parents.
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Kidney, liver, or thyroid disorders in parents.
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Exposure to toxins while still in the womb.
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Family history of congenital conditions.
What Are the Symptoms of Congenital Hypomyelinating Neuropathy?
The main symptoms of congenital hypomyelinating neuropathy are listed below:
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Dyspnea (difficulty breathing).
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Muscle weakness.
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Incoordination.
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Hypotonia (loss of muscle tone).
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Lack of reflexes (areflexia).
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Difficulty walking (ataxia).
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Loss of sensation in part of the body.
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Impaired ability to move.
What Are the Possible Complications of Congenital Hypomyelinating Neuropathy?
Complications of congenital hypomyelinating neuropathy can include:
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Burns and Skin Injuries - A person might not feel temperature changes or pain in parts of their body that are numb.
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Infection - The feet and other areas lacking sensation can become injured without knowing.
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Falls - The loss of sensation and weakness may be associated with frequent falling and a lack of balance.
How Is Congenital Hypomyelinating Neuropathy Diagnosed?
Congenital hypomyelinating neuropathy has a genetic cause. Besides a physical exam, diagnosis may require various other tests. Diagnosis usually requires the following:
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Medical History - A doctor will review the patient’s medical history, including symptoms, lifestyle, exposure to toxins, alcohol consumption, and family history of any neurologic disorders.
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Neurological Examination - The doctor might check the tendon reflexes, muscle tone, strength, the ability to feel certain sensations, and posture and coordination.
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Imaging Tests - Radiological tests can look for tumors, pinched (compressed) nerves, or other defects affecting the blood vessels and bones.
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Nerve Function Tests - Electromyography (EMG) records the electrical activity in the muscles to detect any nerve damage. A thin needle, also called an electrode, is inserted into the muscle to measure electrical activity during the contraction of the muscle. Other nerve function tests include an autonomic reflex screen recording the way autonomic nerve fibers work, a sweat test that checks the body's ability to sweat, and sensory tests recording how one feels touch, vibration, heat, and cold.
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Nerve Biopsy - This involves removing a minute portion of a nerve, usually a sensory nerve, to check for abnormalities.
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Skin Biopsy - The doctor removes a small portion of the skin to look for a reduction in nerve endings.
How Is Congenital Hypomyelinating Neuropathy Treated?
The treatment methods for congenital hypomyelinating neuropathy are listed below:
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Transcutaneous Electrical Nerve Stimulation (TENS) - Electrodes placed on the skin deliver gentle electrical currents at various frequencies. TENS should be used for 30 minutes a day for about a month.
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Physical Therapy - If muscles are weak, physical therapy can help improve movement. They may also need hand and foot support, a cane, a walker, or a wheelchair.
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Pain Reliever - Some Over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs, can relieve mild symptoms. For more severe symptoms, the doctor may prescribe pain relievers.
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Ventilator Support - Due to loss of tone of muscle, it may be difficult for the person to breathe. Hence they can be put on ventilator support for the same.
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Plasmapheresis and Intravenous Immunoglobulin - These procedures, which help keep the immune system in check, may benefit people with certain inflammatory conditions. Plasmapheresis is a process that includes taking blood, removing antibodies and various other proteins from the blood, and returning the remaining blood components to the body. In immunoglobulin therapy, high levels of proteins that act as antibodies (immunoglobulins) are added to the body.
Conclusion
Congenital hypomyelinating neuropathy is an inherited condition that is caused by non-myelination of nerves outside the brain and spinal cord (peripheral nerves) that often cause muscle weakness, numbness, pain, and loss of tone. It may also affect other areas and bodily functions such as digestion, circulation, and urination. It is caused by the mutation in the gene contactin-associated protein 1 (CNTNAP1). This occurs before birth; hence it is a hereditary condition. People with neuropathy generally describe the pain as stabbing, burning, or tingling. The death rate is very high in this condition. Treatment can drastically reduce the pain of peripheral neuropathy. Although this condition is inherited and cannot be prevented by an individual, it can be successfully managed throughout a person’s life by treating the symptoms. A better quality of life can be expected with proper care.
