Amyotrophy: Definition, Types, Causes, Symptoms, Diagnosis and Treatment

It is a progressive wear of the muscular tissues.

Muscle pain is also a symptom. It can occur in middle-aged men with type 2 diabetes. It also occurs with motor neuron disease .

Proximal diabetic neuropathy

Proximal diabetic neuropathy, more commonly known as diabetic amyotrophy, is a nerve disorder that occurs as a complication of diabetes mellitus. It can affect the thighs, hips, buttocks, or lower legs.

Proximal diabetic neuropathy is a disease of the peripheral nerves (diabetic neuropathy) characterized by muscle wasting or weakness, pain, or changes in sensation / numbness in the leg.

Diabetic neuropathy is a rare complication of diabetes. It is a type of lumbosacral plexopathy, or adverse condition that affects the lumbosacral plexus.

There are several ways that diabetes damages nerves, all of which seem to be related to rising blood sugar levels over a long period of time. Proximal diabetic neuropathy is one of the four types of diabetic neuropathy.

Proximal diabetic neuropathy can occur in patients with type 2 and type 1 diabetes mellitus, however, it is more commonly found in type 2 diabetics. Proximal neuropathy is the second most common type of diabetic neuropathy and can resolve with time and treatment.

Signs and symptoms

The signs and symptoms of proximal diabetic neuropathy depend on the region of the plexus affected. The first symptom is usually pain in the buttocks, hips, thighs, or legs. This pain usually affects one side of the body and can start gradually or appear suddenly.

This is often followed by variable weakness in the proximal muscles of the lower extremities. These symptoms, although they often start on one side, can also spread to both sides.

The weakness in proximal diabetic neuropathy is caused by denervation of the specific muscles innervated by the affected plexus regions and thus these muscles may begin to exhibit fasciculations.

Keep in mind that diabetic amyotrophy is a condition caused by diabetes mellitus, but separate from the more common condition of polyneuropathy.


The nerve damage associated with the disease was first thought to be caused by metabolic changes such as endoneural microvessel disease, which is the degeneration of the pericytes due to hyperglycemia and the reproduction of the basement membranes when the pericytes no longer regulate their cycle mobile.

The decreased size of the lumen plus the absence of the pericyte, which regulates capillary blood flow and phagocytosis of cellular debris, leads to ischemia . Nerve biopsies have shifted the view towards an immune mechanism that causes Micro Vasculitis, which could eventually lead to ischemia.

Experimental treatments using immunosuppressive proteins have provided additional corroborative evidence for the theory of the immune mechanism.

Although this disease occurs in patients without diabetes, the prevalence is much higher in diabetics, indicating that although hyperglycemia does not directly cause nerve damage, it may play a role.


Patients with diabetes and proximal pain and weakness (hip, thigh) are often suspected of having diabetic amyotrophy.

The most definitive diagnosis is commonly made with electrodiagnostic studies that include nerve conduction studies and an electromyogram.

Diabetic amyotrophy is often a diagnosis of exclusion in diabetic patients with a lumbosacral plexopathy for which no other cause of lumbosacral plexopathy can be determined.


Proper management of diabetes mellitus can prevent proximal diabetic neuropathy from occurring.

The incidence of proximal diabetic neuropathy incidence is believed to correlate with blood glucose control in diabetics, and is likely to be reversible with better control.

Medication helps reduce pain involved in proximal diabetic neuropathy. Most patients take oral medications prescribed by a doctor.

Common types of medications used to treat diabetic amyotrophy include anticonvulsants (eg, gabapentin , pregabalin) as well as opioid medications, although the latter category is not optimally indicated for neuropathic pain.

Monomelic amyotrophy

Monomelic amyotrophy (MMA), also known as Hirayama disease and non-progressive juvenile spinal muscular atrophy, is a motor neuron disease that was first described by Keizo Hirayama in 1959; Mandavilli Gourie-Devi (et al) introduced the term “monothelial amyotrophy” in 1984.

The disease (disorder) primarily (but not exclusively) affects young men (15-25 years of age) in Asia, with the majority of cases studied in India and Japan.

As of 2011, about 200 cases had been written, starting with the 38 patients in Hirayama’s 1959 study. Both the names for the disorder and its possible causes have been evolving since they were first reported.

Signs and symptoms

Symptoms include a slow onset of muscle atrophy, which stabilizes to a plateau after two to five years after which it neither improves nor worsens. There is no pain or sensory loss associated with monomelic amyotrophy, and fasciculations (involuntary muscle contractions) are rare.

There is debate as to whether this condition represents a focal form of primary lower motor neuron degeneration (i.e., a focal form of spinal muscular atrophy) or a local consequence of chronic compression from a dural expansion in the cervical spine.

In the early stages of the disease, monomeric amyotrophy can be confused with advanced carpal tunnel syndrome and with the early stages of amyotrophic lateral sclerosis (ALS).

The symptoms differ somewhat. Pain and tingling in the hand are typically present in carpal tunnel syndrome and absent from monomelic amyotrophy; loss of function presents differently; With careful electrophysiological study and neurological examinations, the two are distinguished.

In early amyotrophic lateral sclerosis versus monomelic amyotrophy, the presentation is similar.

In amyotrophic lateral sclerosis, hand symptoms are more common proximal and distal than in monomeric amyotrophy, mainly distal, and with amyotrophic lateral sclerosis fasciculations (spasms) are often present in the upper extremities, but rarely in the monomelic amyotrophy.

Monomelic amyotrophy is usually removed from consideration if the disability is expressed in more than one limb or lower extremities (legs), but the absence of symptoms may not rule out amyotrophic lateral sclerosis for three to five years after initial onset.

Electrophysiological texts and reflex tests tend to produce different results, but the interpretation is sometimes subjective.


The exact cause of monomelic amyotrophy is not well understood. The disease is believed to occur when the material that surrounds the spinal cord (thecal sac or dural sac) changes position. This can be caused by repeated downward movements (bending) of the neck.

Changing the position of the dural sac can cause pressure on the spinal cord. This can affect the ability of the signals that are sent from the brain to the arm muscles. This could cause the signs and symptoms of monomelic amyotrophy.

However, it has not been confirmed that pressure on the spinal cord explains why some people develop monomeric amyotrophy. Other possible causes include immune system dysfunction or an infection.


Monomelic amyotrophy is generally not believed to be hereditary; a family bond has been described only in a smaller percentage of cases.

Monomelic amyotrophy is not believed to be caused by changes in a specific gene. Most people with monomelic amyotrophy are the only people with the disease in the family. In some cases, people with monomeric amyotrophy reported having other relatives with the disease.

In one case, two identical twins were reported to develop the disease. This leads researchers to believe that there may be genetic factors that predispose people to developing monomeric amyotrophy.

However, not everyone who has these genetic factors will necessarily develop monomelic amyotrophy. Instead, it is likely a combination of genetic and environmental factors that cause people to develop monomeric amyotrophy.


Monomelic amyotrophy is suspected when a doctor observes the signs and symptoms of the disease, such as muscle weakness in one arm, only beginning during adolescence or early adulthood. The diagnosis can be confirmed with imaging studies and laboratory tests.

Imaging studies that can help confirm a diagnosis of monomelic amyotrophy include magnetic resonance imaging or CT scans. These imaging studies can show signs of compression of portions of the spinal cord.

Laboratory tests may include an electromyograph that shows a reduced response in the nerves that carry signals to the arm muscles. Other possible causes of muscle weakness such as trauma or injury must be ruled out to confirm the diagnosis of monomelic amyotrophy.

There is no cure for monomelic amyotrophy. Research has found ways to better manage the disease, including the use of a cervical collar, muscle-strengthening exercises, and training in manual coordination.

Because early interventions are apparently more helpful, other outcomes and causes, such as carpal tunnel, amyotrophic lateral sclerosis, tumors, and trauma, should be removed as soon as possible.


Unfortunately, there is no cure for monomelic amyotrophy. However, there are treatment options that can help control the symptoms of the disease and slow the progression of muscle weakness.

If doctors think that monomelic amyotrophy is caused by compression of the spinal cord, they may recommend wearing a brace that can be worn around the neck to prevent downward movement (flexion) of the neck.

Other treatment options include muscle strengthening exercises and therapies to improve hand coordination. Surgery for the treatment of monomeric amyotrophy is debated, as there are benefits and risks associated with surgery.

People who are diagnosed with monomeric amyotrophy will likely be recommended to see a neuromuscular specialist who can monitor the progression of the disease.


The long-term outlook for people with monomelic amyotrophy is generally good. Although symptoms of the disease can progress for a few years after the initial muscle weakness begins, symptoms generally stabilize.

Muscle weakness generally affects one arm and is not associated with pain or other symptoms.

Some people with monomelic amyotrophy have loss of function in one hand. This can cause difficulties in caring for yourself, work, and social situations. Sessions with occupational therapists or social workers can help overcome difficulties associated with muscle weakness.

Amyotrophic lateral sclerosis

Some also use the term motor neuron disease for a group of conditions of which amyotrophic lateral sclerosis is the most common.

Amyotrophic lateral sclerosis is characterized by muscle stiffness, muscle spasms, and gradual worsening of weakness due to shrinkage of the muscles. This results in difficulty speaking, swallowing, and eventually breathing.

The cause is unknown in 90% to 95% of cases. The remaining 5-10% of cases are inherited from a person’s parents. About half of these genetic cases are due to one of two specific genes.

The underlying mechanism involves damage to the upper and lower motor neurons. The diagnosis is based on a person’s signs and symptoms, and tests are done to rule out other possible causes.

A medicine called riluzole can extend life by about two to three months. Non-invasive ventilation can result in better quality and length of life.

The disease can affect people of any age, but it usually begins around the age of 60 and in inherited cases around the age of 50. Average survival from onset to death is two to four years. About 10% survive more than 10 years.

Signs and symptoms

The disorder causes muscle weakness, atrophy, and muscle spasms throughout the body due to degeneration of the upper motor and lower motor neurons.

People affected by the disorder may ultimately lose the ability to initiate and control all voluntary movement, although the function of the bladder, bowel, and muscles responsible for eye movement are generally avoided until the final stages of the disorder.

Cognitive or behavioral dysfunction is present in 30-50% of people with ALS. About half of people with ALS will experience mild changes in cognition and behavior, and 10-15% will show signs of frontotemporal dementia.

Repetition of phrases or gestures, apathy, and loss of inhibition are frequently reported behavioral features of amyotrophic lateral sclerosis.

Language dysfunction, executive dysfunction, and problems with social cognition and verbal memory are the most common cognitive symptoms in amyotrophic lateral sclerosis; a meta-analysis found no relationship between dysfunction and disease severity.

About half of people with ALS experience emotional lability, in which they cry or laugh for no reason.

Sensory nerves and the autonomic nervous system are generally unaffected, which means that most people with ALS maintain hearing, sight, touch, smell, and taste.

Initial symptoms

The onset of ALS can be so subtle that symptoms are overlooked. The first symptoms of ALS are muscle weakness or muscle atrophy.

In limb-onset amyotrophic lateral sclerosis, people first experience discomfort when walking or running or even stumbling, and this is characterized by walking with a “foot drop” that is gently dragging on the ground.

In bulbar-onset amyotrophic lateral sclerosis, the initial symptoms will mainly be difficulty speaking clearly or swallowing.

Speech may become difficult, nasal in nature, or more silent. There may be difficulty swallowing and loss of mobility of the tongue.

A smaller proportion of people experience “respiratory-onset” amyotrophic lateral sclerosis, where the intercostal muscles that support breathing are affected first.

Symptoms of upper motor neuron involvement include tight and stiff muscles (spasticity) and exaggerated reflexes (hyperreflexia) including an overactive gag reflex.

An abnormal reflex commonly called Babinski’s sign also indicates upper motor neuron damage.


Although the order and rate of symptoms vary from person to person, the disease eventually spreads to unaffected regions and the affected regions become more affected.

Most people eventually cannot walk or use their hands and arms, they lose the ability to speak and swallow food and their own saliva, and they begin to lose the ability to cough and breathe on their own.

The rate of progression can be measured using an outcome measure called the ‘Revised Amyotrophic Lateral Sclerosis Functional Rating Scale’.

A 12-item instrument administered as a clinical interview or self-reported questionnaire that yields a score between 48 (normal function) and 0 (severe disability); it is the most commonly used outcome measure in clinical trials and is used by physicians to track disease progression.

Although the degree of variability is high and a small percentage of people have a much slower disorder, on average, people with ALS lose approximately 0.9 functional rating scale points per month.

Late stages

Difficulty chewing and swallowing makes eating very difficult and increases the risk of suffocation or aspiration of food into the lungs.

In later stages of the disorder, you can develop aspiration pneumonia, and maintaining a healthy weight can become a major problem that may require insertion of a feeding tube.

As the diaphragm and intercostal muscles of the rib cage that support breathing weaken, measures of lung function, such as vital capacity and inspiratory pressure, decrease.

In respiratory-onset amyotrophic lateral sclerosis, this may occur before significant limb weakness is evident. Most people with ALS die from respiratory failure or pneumonia.


The defining feature of amyotrophic lateral sclerosis is the death of upper and lower motor neurons in the motor cortex of the brain, brainstem, and spinal cord.

Before their destruction, motor neurons develop protein-rich inclusions in their cell bodies and axons. This may be due in part to defects in protein degradation.

These inclusions often contain ubiquitin, and generally incorporate one of the proteins associated with amyotrophic lateral sclerosis: SOD1, TAR DNA-binding protein (TDP-43 or TARDBP) or FUS. Mutant SOD1 can also contribute to the death of motor neurons by generating free radicals.

Excitotoxicity, or cell death caused by elevated levels of intracellular calcium caused by excessive activity of excitatory neurotransmitters, may be a mechanism of amyotrophic lateral sclerosis.

This concept has been supported by an increase in dysfunctional glutamate and glutamate transporter RNA in the cerebrospinal fluid of people with ALS.

This is further supported by the only effective treatment that is an anti-glutaminergic drug (Riluzole), as well as the poor ability to buffer calcium in motor neurons relative to other neurons.

The accumulation of neurofilaments in the axons has been observed in sporadic cases of amyotrophic lateral sclerosis, as well as in patients with SOD1, possibly interfering with axonal transport, leading to cell death from SOD1 toxicity.


About 5-10% of cases are inherited directly from a person’s parents. In general, first-degree relatives of an individual with ALS have a 1% risk of developing ALS.

A defect on chromosome 21, which codes for superoxide dismutase, is associated with about 20% of familial cases of amyotrophic lateral sclerosis, or about 2% of cases of amyotrophic lateral sclerosis in general.

Head injury

Although moderate to severe traumatic brain injury is a risk for amyotrophic lateral sclerosis, whether mild traumatic brain injury increases the rates is unclear.

Amyotrophic lateral sclerosis can also occur more often among US Army veterans, but the reason is unknown.

Other factors

When there is no family history of the disease, it is about 90% of cases, no cause is known. Possible associations for which the evidence is inconclusive include military service and smoking.

Although studies on the military history and frequency of ALS are inconsistent, there is weak evidence for a positive correlation.

Several proposed factors include exposure to environmental toxins (inferred from geographic deployment studies), as well as alcohol and tobacco use during military service.

Other potential risk factors remain unconfirmed, including chemical exposure, electromagnetic field exposure, occupation, physical trauma, and electrical shock.


Various biomarkers for the condition are being studied, but are not in general medical use so far.

Viral infectious diseases such as human immunodeficiency virus (HIV), human T-lymphotropic virus, Lyme disease, syphilis, and tick-borne encephalitis can in some cases cause symptoms similar to amyotrophic lateral sclerosis.

Neurological disorders such as multiple sclerosis, post-polio syndrome, multifocal motor neuropathy, chronic inflammatory demyelinating polyneuropathy, spinal muscular atrophy, and bulbar muscular atrophy can also mimic certain aspects of the disease and should be considered.

Amyotrophic lateral sclerosis must be differentiated from ‘amyotrophic lateral sclerosis mimic syndromes’, which are unrelated disorders that may have a presentation and clinical features similar to amyotrophic lateral sclerosis or its variants.

Due to the prognosis of this diagnosis and the variety of diseases or disorders that can resemble amyotrophic lateral sclerosis in the early stages of the disease, people with amyotrophic symptoms of lateral sclerosis should always obtain a specialized neurological opinion to rule out alternative diagnoses.

Myasthenic syndrome, also known as Lambert-Eaton syndrome, can mimic amyotrophic lateral sclerosis, and its initial presentation can be similar to that of myasthenia gravis, a treatable autoimmune disease that is sometimes confused with amyotrophic lateral sclerosis.

Benign fasciculation syndrome is another condition that mimics some of the early symptoms of ALS, but is accompanied by normal electromyography readings and is not severely handicapped.

Most cases of amyotrophic lateral sclerosis, however, are correctly diagnosed.


This supportive care is best provided by multidisciplinary teams of healthcare professionals who work with the person and their caregivers to keep them as mobile and comfortable as possible.


Riluzole has been found to modestly prolong survival by approximately 2-3 months. It may have a greater survival benefit for those with a bulbar onset.

It is approved by the United States Food and Drug Administration and recommended by the National Institute for Excellence in Health and Care in England and Wales.

Riluzole does not reverse damage already done to motor neurons, but it does affect neurons by reducing their activity by blocking the entry of Na + into neurons, thus blocking the release of chemicals that cause motor neurons to act.

The reduction in activity prevents the destruction of neuronal muscle and therefore the drug can act as a protective chemical. The function of this medicine depends on the amount taken at any one time.

The higher the concentration, the better the drug will protect neurons from debris. The recommended dose of riluzole is 50 mg twice a day for people with known amyotrophic lateral sclerosis for more than five years.

A number of side effects are caused by the drug, including feeling weak in the muscles, but this is normal due to the role of the drug.

Studies have shown that people taking the drug are unlikely to stop responding to it or to develop symptoms that may cause neuron activity to increase again, making it an effective drug for prolonging survival.

In 2015, edaravone was approved in Japan for the treatment of amyotrophic lateral sclerosis after studying how and if it works in 137 people with amyotrophic lateral sclerosis and has obtained orphan drug status in the European Union and the United States.

Medications are also available to help people with pain, such as non-steroidal and anti-inflammatory and opioid medications, depression , sleep disturbances, dysphagia, and constipation .

Baclofen and diazepam are often prescribed to control spasticity caused by ALS, and trihexyphenidyl, amitriptyline, or more commonly glycopyrrolate may be prescribed when people with ALS begin to have trouble swallowing their saliva.

There is no evidence that the medications are effective in reducing muscle cramps experienced by people with ALS.

Support breathing

Respiratory failure is the most common cause of death in people with ALS and is the most prominent symptom, second to destruction of motor neurons and weakening of the muscle.

When the muscles that help you breathe weaken, various symptoms begin to appear, such as shortness of breath with physical activity or speaking, fatigue, morning headaches, poor concentration, and depression .

Biphasic cuirass ventilation has the additional advantage of being able to help clear secretions by using high-frequency oscillations followed by several positive expiratory breaths.

People may eventually consider forms of mechanical ventilation (respirators) in which a machine inflates and deflates the lungs.

To be effective, this may require a tube that passes from the nose or mouth into the windpipe and for long-term use, an operation such as a tracheostomy, in which a plastic breathing tube is inserted directly into the windpipe of the person in an opening in the neck.

Individuals and their families must consider several factors when deciding whether and when to use one of these options. Ventilation devices differ in their effect on quality of life and cost to the person.

Although ventilatory support can alleviate respiratory problems and prolong survival, it does not affect the progression of ALS.

People need to be fully informed about these considerations and the long-term effects of life without motion before making decisions about ventilation support and having in-depth discussions about quality of life.

Some people undergoing a long-term tracheostomy with intermittent positive pressure ventilation with deflated cuffs or uncuffed tracheostomy tubes (leaky ventilation) can speak, as long as their bulbar muscles are strong enough, although in all cases they will lose speech. speaks as the disease progresses.

This technique preserves speech in some people on long-term mechanical ventilation. Other people may use a speech valve, such as a Passey-Muir speech valve, with the assistance and guidance of a speech-language pathologist.

External ventilation machines that use the bilevel positive airway pressure ventilation mode are often used to treat respiratory failure at night and later in the day.

The use of bilevel positive pressure (more commonly known as noninvasive ventilation) has been shown to prolong survival and slow the progression of forced vital capacity.

But long before positive airway pressure is no longer effective, people must decide whether to have a tracheostomy and long-term mechanical ventilation. At this point, some people choose hospice care for the terminally ill.


Physical therapy plays an important role in the rehabilitation of individuals with ALS.

Specifically, physical, occupational, and speech therapists can set goals and promote benefits for people with ALS by delaying loss of strength, maintaining stamina, limiting pain, improving speech and swallowing, preventing complications, and promoting functional independence.

Occupational therapy and special equipment such as assistive technology can also improve the independence and safety of people throughout ALS.

Gentle, low-impact aerobic exercise such as activities of daily living, walking, swimming, and riding a stationary bike can strengthen unaffected muscles, improve cardiovascular health, and help people combat fatigue and depression .

Range of motion and stretching exercises can help prevent painful spasticity and shortening (contracture) of the muscles.

Physical and occupational therapists may recommend exercises that provide these benefits without overloading the muscles, as muscle exhaustion can worsen symptoms associated with ALS, rather than helping people with ALS.

They may suggest devices such as ramps, braces, walkers, bathroom equipment (shower chairs, toilet lifts, etc.), and wheelchairs that help people stay mobile.

Occupational therapists can provide or recommend equipment and accommodations to allow people with ALS to maintain as much security and independence in activities of daily living as possible.

People with ALS who have difficulty speaking may benefit from working with a speech-language pathologist. These health professionals can teach people coping strategies, such as techniques to help them speak louder and more clearly.

As amyotrophic lateral sclerosis progresses, speech-language pathologists may recommend the use of augmentative communication such as voice amplifiers, voice-generating devices, or low-tech communication techniques such as head-mounted laser pointers or self-signals. and no.


People with ALS and caregivers can learn from dietitians how to plan and prepare numerous small meals throughout the day that provide enough calories, fiber, and fluids, and how to avoid foods that are difficult to swallow.

Providing meals with vitamin E and taking vitamin E supplements has been shown to slow the progression of ALS. People can begin to use suction devices to remove excess fluids or saliva and prevent suffocation.

Occupational therapists can help with adaptive equipment recommendations to facilitate the physical task of self-feeding. Speech and language pathologists make food choice recommendations that are most conducive to your unique abilities and deficiencies.

When people with ALS can no longer eat enough, doctors may advise inserting a feeding tube into the stomach.

End of life care

Home and hospice social workers and nurses help people with ALS, their families, and caregivers cope with medical, emotional, and financial challenges, particularly during the final stages of the disease.

Social workers provide support such as assistance with obtaining financial aid, organizing a durable power of attorney, preparing a living will, and finding support groups for patients and caregivers.

Home nurses are available not only to provide medical care, but also to teach caregivers about tasks such as maintaining respirators, feeding, and moving people to avoid painful skin problems and contractures.

Hospice nurses work in consultation with physicians to ensure appropriate medication, pain control, and other care that affects the quality of life for people with ALS who wish to remain at home.

The home hospice team can also counsel people with ALS and caregivers about end-of-life problems.