Diabetic Peripheral Neuropathy

What is Diabetic Peripheral Neuropathy?

Peripheral neuropathy is a term that covers a wide variety of conditions that affect the way your peripheral nervous system functions. People with peripheral neuropathy often report feeling different levels of numbness, tingling, aching, weakness, and pain, which can often get worse at night. These feelings could be surface level, deep within, or severely painful. While metabolism issues are most commonly associated with limb pain in these cases, many other conditions also warrant consideration.

There are many causes of peripheral neuropathy, but the most common type is diabetic peripheral neuropathy (DPN). This can have serious outcomes, ranging from unusual sensory experiences to losing a limb or even life. Detecting DPN symptoms early helps prevent nerve-related foot sores to fight against potential harm and fatalities due to slow wound healing. This slow healing can lead to limb injuries, infections spreading from local to systemic, blood poisoning, and even death. Diagnosis of DPN primarily relies on a patient’s history and testing for changes in sensation like temperature or pinpricking changes, vibration sensation, and risk of ulcers with pressure tests. If a patient’s symptoms aren’t typical, they may need a neurologist’s consultation and special tests including nerve activity studies and nerve density tests.

The exact reason behind DPN isn’t clear, but there are many theories. Some believe metabolic, neurovascular, and autoimmune pathways could be the cause. Factors such as physical pressure (like from carpal tunnel syndrome), genetics, and habits like chronic alcohol use and smoking have all been linked. Persistent high blood glucose levels can lead to cells resisting insulin, causing stress, inflammation, and cell damage. This typically starts with damaging the nerve fibers responsible for sensation and involuntarily body functions, gradually leading to a loss of sensation in the skin and foot joints. Managing DPN includes a mix of preventative actions (like patient education, foot care, suitable footwear, and yearly foot checks), glucose control, diet changes, weight loss, and pain management. Half of all diabetic peripheral neuropathies may not have symmetrical symptoms. If not detected early and the right foot care is not taken, patients risk greater injury due to less sensation in their feet.

What Causes Diabetic Peripheral Neuropathy?

Metabolic disorders are often the main reason for pain in the limbs, typically caused by conditions referred to as peripheral neuropathy. A variety of factors can cause peripheral neuropathy, but diabetes is the most common one. Some other causes might include:

* Excessive alcohol use
* Lack of certain nutrients (for instance, low amounts of B12, high amounts of B6)
* Guillain-Barre syndrome, a rare neurological disorder
* Harmful substances like toxins from chemotherapy or an overdose

Certain hereditary or genetic conditions can also be responsible, such as Charcot-Marie-Tooth disease, amyloidosis, and porphyria. Infections (like HIV), inflammatory conditions (like lupus and rheumatoid arthritis), an underactive thyroid, cancer, and physical injuries can also be contributors.

When it comes to Diabetic Peripheral Neuropathy, specifically, several risk factors increase the likelihood of developing the condition:

* Old age
* High blood pressure
* Peripheral vascular disease, a circulation disorder that affects blood vessels outside of the heart and brain
* Smoking
* Dyslipidemia, an abnormal amount of lipids in the blood
* Difficulty controlling blood sugar levels
* Having had diabetes for a long time
* Obesity
* Heavy alcohol drinking
* Having a certain type of HLA genotype referred to as HLA-DR3/4

Risk Factors and Frequency for Diabetic Peripheral Neuropathy

When someone is diagnosed with diabetes, it’s estimated that 10% to 20% of those people are also found to have Diabetic Peripheral Neuropathy (DPN) at the same time. Moreover, for those with a long history of diabetes, DPN is even more common. After having diabetes for 5 years, 26% of people will have DPN, and at the 10-year mark, this increases to 41%. In fact, up to two-thirds of people with diabetes are expected to develop DPN during their lifetime.

• DPN can happen in both Type 1 and Type 2 diabetes, however, it’s more common in those with Type 2 diabetes due to the longer duration and higher rates of other health problems.
• Diabetes is also the main cause of a condition called Charcot neuroarthropathy, occurring in up to 29% of people with peripheral neuropathy.
• About half of the people with DPN experience uneven changes in how they sense things.
• Factors such as obesity and genetics can increase one’s risks of getting diabetes.
• Peripheral and autonomic neuropathies are among the top causes of disability in diabetics.
• If a diabetic person gets a foot ulcer, their chance of death in 5 years is 2.5 times higher than a diabetic without a foot ulcer.
• The rate of emergency room visits for foot ulcers and related infections in diabetics is higher than that for heart failure, kidney disease, depression, and most types of cancer.

Signs and Symptoms of Diabetic Peripheral Neuropathy

Peripheral neuropathy, a condition that affects the nerves, is frequent in people with diabetes. According to the American Diabetes Association, it should be tested for in people diagnosed with type 2 diabetes and five years after a type 1 diabetes diagnosis. It’s usually diagnosed through an examination that tests for changes in small fiber sensation (felt by changes in temperature or pricks), large fiber sensation (felt by vibrations), and an individual’s risk of developing ulcers, tested by pressure on the skin using a specific medical tool known as a 10 g monofilament.

Doctors should assess the complete medical history of the patient, information about any conditions like diabetes, obesity, high cholesterol, and high blood pressure. They should also check medication use and other neuropathy risk factors such as age and diabetes control. Peripheral neuropathy commonly shows as a feeling of burning, numbness, or tingling in the feet that gets worse at night. Patients may also feel a generalized disturbance in their feet that can affect their ability to walk and take part in daily life. This condition is usually seen in around 80% of peripheral neuropathy patients and can take several years to fully manifest.

Medical professionals should conduct a physical examination of the lower part of the body. This involves testing muscle strength, reflexes, and awareness of sensations like touch, vibration, and spatial perception. They may also look for dermatological signs like dry or cracked skin and check for foot abnormalities such as hammertoes.

Doctors assess small fiber sensation by measuring temperature changes or pinprick testing. They evaluate a patient’s risk for ulcers by testing their ability to feel pressure. Similarly, evaluation of large fibers is done through vibratory sensation. Timing the length of time a patient feels a vibrating tuning fork on a specific joint of the foot can help track sensory deficits. Other symptoms like decreased light touch feeling or loss of ankle reflexes occur sooner in the disease progression, while loss of protective sensation tends to occur later. There are other tests, such as needle electromyography (EMG), nerve conduction velocity testing, and epidermal nerve fiber density testing. Still, these are often both painful and expensive.

Patients with the condition may also experience symptoms of autonomic neuropathy, which affects internal organs and can have various effects on the body, including:

• GI: Abdominal discomfort, difficulty swallowing, nausea, and changes in bowel habits
• Cardiac: Low blood pressure, high heart rate, variable heart rate, fainting
• Bladder: Weak urine stream, difficult urination, incomplete bladder emptying
• Skin: Heat intolerance, sweating while eating, excessive sweat
• Nervous: Nerve-related conditions such as carpal tunnel syndrome, nerve root disease, and nerve issues in the lower back, neck, and several cranial nerves

Testing for Diabetic Peripheral Neuropathy

In situations where a patient experiences unusual symptoms like sudden onset, severe motor impairment, or unbalanced abnormal sensations, they might need to see a neurologist for special tests. These can include tests to check how well nerves are conducting electrical signals and checks on nerve fiber density.

In some cases, patients may need to have a procedure known as electromyography along with nerve conduction studies, especially if symptoms are severe, getting worse quickly, or if there’s muscle weakness.

If doctors think a condition called small fiber neuropathy might be the problem, they often use a test that looks at nerve fiber density in the skin. This test measures nerve fibers in the skin and is particularly useful for unexplained cases. Doctors can assess the number and shape of axons, or long, slender projections of a nerve cell, and compare the density of nerve fibers in a patient’s skin to what’s normal for their age group.

Some mild symptoms might not need any laboratory tests. But if you have ongoing symptoms that haven’t been explained, your doctor might want to run lab tests. These could include checks on blood sugar, hemoglobin (a protein that carries oxygen in the blood), blood cells, how quickly red blood cells sink in a tube of blood (which can help determine inflammation), protein levels, and vitamins B1, B6, and B12.

Treatment Options for Diabetic Peripheral Neuropathy

Diabetic Peripheral Neuropathy (DPN) management involves various strategies. These include preventive measures like patient education, proper foot care, suitable footwear and an annual foot exam. Balanced blood sugar levels, dietary changes, weight loss and pain control also help.

Many patients with this condition experience a mild to moderate loss of feeling, but they can still sense important safety sensations in their feet. In such cases, providing clear information about the cause of the numbness can allay their concerns. Regular check-ups are crucial, and it’s essential to rule out peripheral arterial disease and radiculopathy. Proper control of blood sugar can help to lessen disturbances of sense perception within a year.

The 2022 edition of the Current Pain and Headache Reports suggested a treatment plan for painful diabetic neuropathy, which is divided into conservative, pharmaceutical, and interventional therapies.

With conservative therapy, physical therapy (like weight-bearing exercises and Tai chi massage therapy), health management (such as optimizing blood sugar levels, managing co-existing conditions, losing weight and maintaining a balanced diet) and minimally invasive treatments like acupuncture and transcutaneous electrical nerve stimulation (TENS), are utilized.

For pharmaceutical therapy, medications are listed in order of preferred usage. First line drugs include gabapentinoids (like pregabalin and gabapentin) and Duloxetine. Second in line are serotonin and norepinephrine reuptake inhibitors, Tricyclic antidepressants and some other medications. If these don’t work, Tramadol, opioid and intravenous agents are tried.

Interventional therapies include different types of spinal cord and nerve stimulations. If these interventions fail, intrathecal drug delivery systems are utilized.

DPN can also affect the digestive, endocrine, and vascular systems. So, these must also be monitored and certain specific treatments may be necessary. For example, diabetic gastroparesis can be managed with certain drugs while erectile dysfunction might be treated with inhibitors or a penile prosthesis. Increased salt and fluid intake along with compression stockings can potentially improve orthostatic hypotension.

Some patients may benefit from supplements like Omega-3 fatty acids, Vitamin D and alpha lipoic acid, but this is subject to the patient’s response to these treatments, and more research is needed. Furthermore, certain medical foods and vitamin supplements may be beneficial, although again, their effects are still being studied.

Lastly, a capsaicin 8% patch treatment may provide modest improvements in pain and sleep quality for patients with painful diabetic peripheral neuropathy.

What else can Diabetic Peripheral Neuropathy be?

If a patient shows symptoms of DPN (Diabetic Peripheral Neuropathy), doctors would typically consider other potential causes for the symptoms which may include:

• Neuropathy due to excessive alcohol intake
• Neuropathy related to poor nutrition
• Uremic neuropathy (a nerve condition associated with kidney disease)
• Vasculitic neuropathy (nerve damage due to blood vessel inflammation)
• Neuropathy due to a lack of Vitamin B12
• Neuropathy caused by exposure to toxic metals

These alternatives are considered in order to ensure an accurate diagnosis and appropriate treatment for the patient. Remember, it’s important for healthcare professionals to look at the big picture and not jump to conclusions based on a few symptoms.

What to expect with Diabetic Peripheral Neuropathy

People with poorly controlled diabetes suffer more from diabetic peripheral neuropathy (DPN) than those who keep their diabetes under good control. DPN can cause several issues, like skin breakdown, infection, and ulcers, which if left untreated, can lead to amputation. Unfortunately, DPN treatments aren’t always effective, and heart problems are common among these patients. Fewer than one-third find their pain substantially reduced. As a result, most people with DPN often have a poor quality of life.

Possible Complications When Diagnosed with Diabetic Peripheral Neuropathy

Some common problems that can occur due to Diabetic Peripheral Neuropathy (DPN) include:

• Amputations of the toes, foot, or leg
• Infections in the foot
• Falling due to feeling dizzy
• Diarrhea, failure to gain weight and grow as expected, and dehydration
• Pain
• Heart disease related to nerve damage, which can be fatal

Preventing Diabetic Peripheral Neuropathy

Preventative measures are key to controlling diabetic peripheral neuropathy, or DPN. As per the guidelines set by the American Diabetes Association, diabetic individuals should go in for a thorough foot check-up once a year and a visual exam every 3 to 4 months when they visit their doctor. It’s also important for patients to consistently monitor their blood sugar levels and examine their feet every day for things like sores, wounds, or cracked skin.

In addition, patients should stick to the diet given by their doctor and take prescribed medicines on time. Doctors, on their part, should explain to patients how habits like drinking and smoking can lead to peripheral neuropathy, and help them form a quitting plan, if required. Last but not least, to prevent damage to their feet, patients should avoid wearing shoes that don’t fit them properly.