What Is Primary Lateral Sclerosis?
A motor neuron disease known as primary lateral sclerosis (PLS) causes the brain's nerve cells that control movement to fail over time. The voluntary muscles that control the legs, arms, and tongue become weak as a result of PLS. The affected individuals may have problems with trouble maintaining their balance, move slowly, or be clumsy. The patient eventually may develop difficulty speaking, chewing, and swallowing.
Although it can occur at any age, the majority of cases occur between the ages of 40 and 60, and males are more likely to develop than females. A very rare form of PLS which begins in early childhood, called juvenile primary lateral sclerosis is brought on by the transmission of an abnormal gene from one parent to the next. Amyotrophic lateral sclerosis (ALS), a more common motor neuron disease, is frequently confused with PLS. PLS progresses more slowly than ALS and rarely causes death, despite likely being related to ALS.
What Are the Symptoms of Primary Lateral Sclerosis?
Primary lateral sclerosis symptoms typically begin in the legs and take years to develop. PLS occasionally begins in the hands or tongue and moves down the spinal cord to the legs. Nevertheless, the disease's effects vary greatly from person to person. Examples of the signs and symptoms include:
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Leg stiffness, weakness, and muscle spasms (spasticity), rarely beginning in just one leg but eventually spreading to the arms, hands, tongue, and jaw.
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Clumsiness, tripping, and difficulty maintaining balance.
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Slowed movement.
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Clumsiness of the hands.
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Difficulties faced during chewing and swallowing.
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Hoarseness, along with drooling, and slow, slurred speech.
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Occasionally, frequent, rapid, and severe emotional shifts (mood lability).
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Breathing and bladder issues occasionally develop late in the disease.
What Causes Primary Lateral Sclerosis?
Upper motor neurons, the nerve cells in the brain that control movement, slowly fail over time in primary lateral sclerosis. Because of this, the motor neurons in the spinal cord that control voluntary muscles cannot be activated by the nerves. This loss results in difficulties with speech and swallowing, as well as difficulties with balance, slowed movement, weakness, and clumsiness.
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Juvenile Primary Lateral Sclerosis: Mutations in the ALS2 gene result in juvenile PLS. Even though it is not clear how this gene causes the disease, researchers do know that the ALS2 gene tells how to make the protein alsin, which is found in motor neuron cells. In a person with juvenile PLS, when the instructions are changed, the protein alsin becomes unstable and fails to function properly, affecting normal muscle function. Juvenile PLS is an autosomal recessive disease, which means that even though neither parent is afflicted with the condition, they must both be carriers of the gene in order to pass it onto their offspring.
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Adult-onset Primary Lateral Sclerosis: It is unknown what causes PLS, which manifests in adulthood. It is unknown why or how it begins, and the majority of the time, it is not an inherited condition.
What Are the Complications of Primary Lateral Sclerosis?
Primary lateral sclerosis progresses very differently from person to person and can last as long as 20 years on average. While some people are able to continue walking, others will eventually require wheelchairs or other assistive devices. Adult-onset PLS is not thought to shorten life expectancy in most cases, but as more muscles become disabled, it can gradually affect the quality of life.
A person with weaker muscles may fall, which can result in injuries. Poor nutrition as a result from swallowing and chewing difficulties. Performing activities of everyday living, like washing and dressing, may become troublesome.
How Is Primary Lateral Sclerosis Diagnosed?
Primary lateral sclerosis (PLS) cannot be diagnosed with a single test. In fact, doctors are likely to order a number of tests to rule out other diseases because the disease can mimic the signs and symptoms of other neurological disorders like ALS and multiple sclerosis.
The doctor may order the following tests after carefully documenting the patient's medical history and family history and conducting a neurological examination:
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Blood Tests - Infections and other potential causes of muscle weakness are checked for in blood tests.
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MRI - An MRI (magnetic resonance imaging) or other imaging trials of the cerebrum or spine could uncover indications of nerve cell degeneration. An MRI can likewise show different reasons for the other associated symptoms, like structural abnormalities, spinal cord tumors, or multiple sclerosis.
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Electromyogram (EMG) - A needle electrode is inserted by a doctor through the skin into a variety of muscles during an electromyogram (EMG). The test looks at how the muscles' electrical activity changes when they contract and when they rest. This test also measures the involvement of lower motor neurons, which can help distinguish ALS, which affects both upper and lower motor neurons, from PLS, a disease of the upper motor neurons.
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Nerve Conduction Studies - These tests measure the nerves' capacity to send impulses to muscles in various parts of the body by using a low amount of electrical current. If a person has nerve damage, this test can detect that.
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Spinal Tap (Lumbar Puncture) - Small amounts of the fluid that surrounds the brain and spinal cord (cerebrospinal fluid) are extracted from the spinal canal with a thin, hollow needle for laboratory analysis. A spinal tap can be used to rule out infections, multiple sclerosis, and other conditions.
Because early ALS can look like PLS until additional symptoms appear a few years later, doctors may delay diagnosis for three to four years. The patient may be approached to return for repeat electromyography testing for three to four years before the PLS analysis is affirmed.
When juvenile PLS is suspected, genetic testing may be performed. Genetic counseling may also be suggested.
How Is Primary Lateral Sclerosis Treated?
Primary lateral sclerosis cannot be stopped, treated, or reversed. The following options are available for treatment, which focuses on relieving symptoms and preserving function.
Medications:
In order to alleviate symptoms, the doctor may prescribe the following medications:
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Emotional Changes - If the patient's emotions change frequently, quickly, and strongly, the doctor may give them antidepressants.
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Muscle Spasms (Spasticity) - Spasticity, or muscle spasms, can be treated with medications like Baclofen, Tizanidine, or Clonazepam. These medications are typically taken orally. The doctor may recommend surgically implanting an intrathecal baclofen medication pump to deliver Baclofen directly to the spinal fluid if the spasticity is not controlled with oral medication.
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Drooling - Amitriptyline and other medications may help with drooling.
Other Treatment Options:
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Physical and Occupational Therapy - Muscle strength, flexibility, and range of motion can all be preserved and joint immobility can be prevented through stretching and strengthening exercises.
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Speech and Language Therapy - Speech therapy may assist with communication and swallowing if PLS affects the facial muscles.
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Nutrition Support - A nutritionist can provide dietary recommendations, nutritional supplements, or customized feeding strategies to assist a patient in maintaining their weight if the patient has difficulty chewing and swallowing, making it difficult for them to eat.
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Assisted Devices - Physical or occupational therapists may periodically assess a patient as PLS progresses to determine whether they require a brace, cane, walker, or wheelchair. Devices for assistive technology might make communication easier.
Conclusion:
A rare neuromuscular disease known as primary lateral sclerosis (PLS) causes gradual weakness in voluntary muscle movement. Motor neuron diseases are a group of disorders that include PLS. PLS does not kill. There is no treatment, and the symptoms vary in their progression. Some people may be able to walk around without help, but others will eventually need wheelchairs, canes, or other aids.
