Chronic inflammatory demyelinating polyneuropathy (CIDP) is a disorder that affects an individual's nerves, causing the patient to feel progressive weakness and loss of sensory function in the arms and legs. The cause of CIDP is currently not clear, but it is thought to be associated with an inappropriate attack on the nerves by the affected individual's immune system. More males are affected by chronic inflammatory demyelinating polyneuropathy than females, and the condition can occur at any age. Symptoms are known to last for at least eight weeks, even with ongoing treatment. Making a diagnosis of CIDP is typically challenging due to the characteristics of the disorder. Nerve conduction testing, lumbar puncture, MRI scans, and electromyography are all diagnostic tests that may be utilized in individuals suspected to be affected by CIDP. Treatment includes the use of corticosteroids, immunoglobulin, and plasma exchange.
Fatigue is not the same as when an individual feels drowsy or sleepy. It is characterized by an individual who has no energy and no motivation. Several contributing mechanisms can cause an individual with chronic inflammatory demyelinating polyneuropathy to experience fatigue. Fatigue may occur as a result of their immune system attacking the protective myelin sheath around the nerves that run their autonomic nervous system. The autonomic nervous system is responsible for managing heart rate, blood pressure, respiratory rate, digestion, urination, and pupillary response. Numerous things can go wrong with these nerves when they become vulnerable to damage, such as blood pressure that is too low, decreased heart rate, reduced respiration rate, and a slower metabolism. These dysfunctions can cause an affected individual to have less energy than usual and feel fatigued. Additionally, the energy the immune system cells consume while they carry out attacks on the individual's healthy myelin sheath can cause them to have lower energy.
Numbness And Tingling
The immune system in chronic inflammatory demyelinating polyneuropathy patients may attack the large-diameter sensory nerve fibers since they tend to be the most heavily myelinated. The sensory nerves are responsible for communicating information about pain and temperature to an individual's brain. When the myelin sheath around the sensory nerves is eaten away by the inappropriate autoimmunity of the immune system, the nerves become more susceptible to damage and dysfunction. Nerve impulses do not conduct from one nerve to the next very well without their insulating and protective myelin sheathing. Nerves damaged past their sheathing layer may only transmit partial impulses or may not transmit impulses at all. When no impulses are sent to the brain upon painful stimuli, it is described as numbness. Nerves that send partial or disrupted impulses to the brain upon pain and or temperature stimuli tend to produce a sensation that can be described as tingling.
Progressive Limb Weakness
Generally, motor system dysfunction due to the weakness of the muscles is more prevalent in individuals affected by chronic inflammatory demyelinating polyneuropathy than sensory nerve malfunction. The most common pattern of progressive weakness of the limbs occurs in a patient's legs and arms in a symmetric fashion. In the earlier stages of CIDP, the patient may not exhibit muscle wasting or atrophy. However, muscle tone may appear to be decreased in individuals in the later stages of the illness. Muscle weakness occurs in individuals who have CIDP because the immune system destroys the myelin sheathing that covers the nerves responsible for transmitting impulses that tell the muscles to contract. Muscle weakness describes the inability to move a muscle when the greatest effort is made to do so. This malfunction occurs when damage has been done to the nerve sheathing, and the impulses that trigger the contraction of the muscle cannot reach the muscle tissue itself. Limb weakness in affected individuals often presents as abnormalities in their gait.
Loss Of Reflexes
Reflex describes the sudden, involuntary movement of a body part in response to certain stimuli. Human reflexes are automatic responses the body makes without the individual having to think about it consciously. Reflexes work through what is called reflex arcs, where the reaction occurs before the actual impulse even reaches the brain. Monosynaptic reflexes are made of a motor neuron and a sensory neuron, and polysynaptic reflexes contain multiple interneurons. The reflexes most affected by chronic inflammatory demyelinating polyneuropathy are their deep tendon reflexes. Deep tendon reflexes are considered monosynaptic reflexes and occur when a rapid muscle stretch provides stimulation to the individual's muscle spindles. The sensory root relays this impulse to the motor neuron that supplies the particular muscle, which results in a rapid muscle contraction. Reflexes are lost in CIDP patients because the immune system destroys the myelin sheath around the lower motor neurons, interrupting the process of impulse communication.
Other Abnormal Sensations
An individual may feel other abnormal sensations or experience paresthesia when affected by chronic inflammatory demyelinating polyneuropathy. Affected individuals sometimes describe these abnormal sensations like the feeling of pins and needles in the affected part of the body. This sensation is the same type of feeling that occurs when a healthy individual sits on top of their foot for an extended period. Other sensations reported in CIDP patients include achiness or burning pain. Some individuals explain this sensation to be a form of itchiness or prickling. These abnormal sensations may occur in individuals with CIDP on a constant or intermittent basis depending on the severity of their illness. These abnormal sensations may radiate from one spot out to other regions. The presence and extent of abnormal sensations in an individual affected by CIDP is dependent on how much damage the myelin sheathing around their nerves has sustained. The poor conduction of impulses or the partial conduction of impulses due to the absence of the myelin sheath causes a patient to feel abnormal sensations.
Diplopia is a term used to describe when an individual sees a double image of a single object. It is also called double vision. The two different images an affected individual sees can be one on top of the other, side by side, or both. Chronic inflammatory demyelinating polyneuropathy can cause damage to the nerves in the brain responsible for the transmission of visual information or the nerves responsible for operating the muscles that control the movements of the eyes. In a healthy individual, the nerves in the peripheral and central nervous systems are protected by a fatty substance referred to as myelin. This myelin sheath helps the nerves conduct impulses better. The myelin sheath around the nerves in a chronic inflammatory demyelinating polyneuropathy patient becomes damaged and breaks down. When this malfunction affects the muscles responsible for eye movement, the affected individual may experience double vision.
Dysphagia is a term used to describe when an individual is not able to move food from their mouth to their esophagus (swallow) properly. Swallowing requires the collaboration and cooperation of numerous brain tissues, nerves, and muscles to carry out properly. Individuals affected by chronic inflammatory demyelinating polyneuropathy may experience difficulty swallowing regularly. This problem can manifest in several ways, such as an inability to get liquid and food to go down the esophagus on the first try, the regurgitation of food or liquid after swallowing, unintentional weight loss from lack of proper nutrition, gagging when swallowing, choking when swallowing, and coughing when swallowing. The nerves that move the muscles responsible for contracting and forcing food and liquid down the throat can become damaged by CIDP, causing patients to have difficulty swallowing.
Clumsiness is a symptom where an individual has poor movement ability, poor coordination, or poor muscle actions. The damage nerves incur in a CIDP patient due to the absence of myelin causes the muscles to be unable to work properly in the affected part of the body. Individuals affected by clumsiness as a result of chronic inflammatory demyelinating polyneuropathy tend to experience weakness in the legs that makes it difficult for them to walk and stand, tripping on any ground that is not perfectly flat, problems with stepping onto a curb due to a clumsy gait, an inability to climb up or downstairs, and an inability to stand from a sitting position. Individuals who experience clumsiness in their arms or hands due to chronic inflammatory demyelinating polyneuropathy may experience problems with turning a key in a lock, issues with fastening buttons on clothing, difficulty when brushing their hair and teeth, and problems picking up small objects like coins or a pen.
Pain is an uncommon symptom only seen in a portion of chronic inflammatory demyelinating polyneuropathy patients. An affected individual's immune system attacks the protective myelin sheaths around the nerves outside of their spinal cord and brain, leaving them exposed to oxidative stress and other damaging processes. These processes cause the exposed and unprotected nerves to become inflamed and irritated. When the nerve fibers in an individual's body experience damage, the immune system rushes to the site and induces inflammatory processes. The irritation of the nerve fibers causes nerve impulses to be sent to the individual's brain that are interpreted as pain. Inflammation in the nerve tissues involves the dilation of the blood vessels, which produces swelling. The mechanism of swelling alone can cause the nerve fibers to become irritated from mechanical compression and transmit pain signals to the brain.