What is Diabetic Neuropathy?

Jul 29

Diabetic neuropathy is a form of nerve damage that can occur for people living with diabetes. When blood sugar is elevated for a long period of time, it can damage peripheral nerves throughout your body. Diabetic neuropathy most commonly affects nerves in the legs and feet.

Diabetic neuropathy symptoms can range from pain and numbness in your legs and feet to more systemic problems with vision, digestion, urination, circulation and cardiac function. These symptoms can range from mild to disabling.

How Common is Diabetic Neuropathy?

The prevalence of neuropathy in diabetic patients has been estimated at 28.5%, with a greater frequency in type 2 than type 1 diabetics. The prevalence of increases with age, with 44.2% of diabetics over age 70 experiencing neuropathy symptoms (2). Other studies have estimated that as high as 60-70% of diabetics experience neuropathies. The large number of prediabetics and people living with undiagnosed type 2 diabetes makes exact prevalence numbers hard to calculate, however we can expect that these numbers will continue to increase as our obesity rates inexorably rise.

What Causes Diabetic Neuropathy?

Diabetes is the most common cause of peripheral neuropathy in the world. Both type 1 (insulin-dependent) and type 2 diabetes are commonly complicated by peripheral nerve disorders (1). Diabetic neuropathies are caused by a demyelination of peripheral nerve fibers, leaving the nerves unprotected, uninsulated, and prone to degeneration and/or cell death.

What are the Symptoms of Diabetic Neuropathy?

Numbness and tingling, loss of skin sensation and increased pain sensations are the most common symptoms of diabetic neuropathy. Other symptoms may include difficulty with balance, sensations of bloating or fullness, coordination difficulties, and muscle weakness.

What are the Risk Factors for Diabetic Neuropathy?

The duration of diabetes and hemoglobin A1c (HbA1c) levels are major predictors of diabetic neuropathy. Insulin resistance and hypertension are also common risk factors, as is obesity.

Elevated levels of serum triglycerides, hypertension, and low high-density lipoprotein (HDL) levels are consistently associated with diabetic neuropathy in patients with type 2 diabetes. Other risk factors include smoking, alcohol abuse, increased height and older age (9).

There appear to be a number of genetic risk factors for developing diabetic neuropathy. Polymorphisms in ACE (encoding angiotensin-converting enzyme) and MTHFR (encoding methylenetetrahydrofolate reductase) have been shown to increase the risk of developing diabetic neuropathy (10).

What are the Complications of Diabetic Neuropathy?

Diabetic neuropathy can produce serious complications, including digestive problems such as gastroparesis, bladder retention and urinary incontinence, sexual dysfunction, difficulty with blood pressure regulation, poor control of body temperature, and infections that can lead to the loss of a toe. Severe cases may even require the amputation of a leg.

How Does Diabetic Neuropathy Affect the Brain?

The brain requires constant feedback from the body to understand where it is in space. It needs to understand the stresses on muscles and joints at all times in order to coordinate proper motor activity. This input comes through the peripheral nerve fibers that can be damaged in diabetic neuropathy. As a result, balance and coordination can be impaired. This can lead to increased risks for falls and injuries.

The loss of stimulation to the brain from diabetic neuropathy can lead to breakdown and degeneration of areas of the brain associated with processing sensations from the body. Imaging studies demonstrate changes in functional connectivity associated with body perception and pain processing in people suffering with chronic diabetic neuropathies (6). Diabetic neuropathy has even been shown to be associated with cognitive impairment due to similar mechanisms (7).

Diabetic neuropathy develops as a consequence of diabetes, which itself has substantial negative impacts on brain function. Performance on cognitive tasks assessing learning, reasoning, and complex psychomotor performance has been shown to degrade in relation to poor glycemic control with type 2 diabetes.

Elevated hemoglobin A1C has been linked to reduced performance on neurocognitive tests assessing memory, learning, and executive functions in subjects with type 2 diabetes. Reductions in measures of motor speed and psychomotor efficiency can be seen in diabetic patients in midlife, and neurocognitive changes have been associated with a reduction in white matter volume or an alteration in white matter microstructure.

Reduction in gray matter density in brain regions responsible for language processing and memory and generalized atrophy have also been identified in young adults with long-standing type 1 diabetes. Patients with chronic hyperglycemia, early onset of diabetes, or recurrent severe hypoglycemia appear to be at particular risk for the development of changes in brain structure and function over time (11).

Uncontrolled blood sugar can lead to a number of negative and harmful neurological consequences. Hyperglycemia has been shown to promote cognitive dysfunction, depression, and dementia, as well as to exacerbate the effects of stroke. Hypoglycemia can similarly lead to cognitive dysfunction, along with seizures and acute loss of consciousness (12).

Uncontrolled glucose levels have also been shown to negatively impact the vestibular system. The brain’s inner ear vestibular pathways are critical for understanding where the body exists in space and promoting stabilization reflexes. They work in tandem with proprioceptive feedback from the feet and legs to help the brain resist falls. The vestibular system can be compromised in diabetes, and when coupled with a loss of sensory feedback from the feet, can markedly increase the risks of fall and injury (13).

How is Diabetic Neuropathy Diagnosed?

Diabetic neuropathy is usually diagnosed through a proper history and physical examination. Diabetic neuropathy primarily affects peripheral nerve fibers known as large diameter afferents. These conduct sensations of touch, pressure, vibration, and joint position into the central nervous system. They also conduct motor output from the spinal cord and brain to control muscles. When these fibers are damaged, sensory perception is decreased in the distribution of the affected nerves, tendon reflexes are decreased, and muscle tone and strength is affected.

Additional tests may be employed to confirm the diagnosis, including nerve conduction velocity and electromyography studies, or autonomic function tests of blood pressure and sweating.

How is Diabetic Neuropathy Usually Treated?

The best way to prevent diabetic neuropathy is, unsurprisingly, to avoid developing diabetes. While that may seem simple, the standard American diet is so high in carbohydrates, saturated fats, and proinflammatory foods that it almost seems like it was specifically designed to induce diabetes. The average American is significantly overweight, and rates of childhood obesity are higher than ever. Type 1 diabetes is a genetic autoimmune disorder that for some cannot be avoided, but type 2 diabetes is a disease of lifestyle. We can all change our lifestyles to reduce diabetes risk. Regular exercise, adequate sleep, reducing stress, and limiting exposure to environmental toxins can all help prevent the development of diabetes.

Diet is the most important factor in preventing and managing diabetes. Diets low in carbohydrates, saturated fats, and processed foods have shown to be the most beneficial in preventing and reversing diabetes. Multiple studies have shown the benefit of the Mediterranean diet to prevent diabetes (4). This diet involves restricting sugar-sweetened beverages and avoiding added sugars. It also involves avoiding processed meat, refined grains, refined oils and other highly processed foods. This diet is also low in red meat. It encourages intake of fresh fruits and vegetables, with high intake of nuts, seeds, legumes, potatoes, whole grains, herbs, spices, fish, seafood and extra virgin olive oil. This diet allows limited intake of poultry and dairy.

Once diabetic neuropathy has taken hold, proper foot care becomes essential. The loss of sensory feedback from the feet can make it difficult to notice small injuries such as cuts, blisters, and ingrown toenails. The poor circulation in diabetes makes it easier for these to become infected, which can lead to poor wound healing, ulcers, and in severe cases, the need for limb amputation.

How is the NeuroRescue Program Different?

Beyond dietary recommendations, there are treatments available to directly promote the viability of remaining peripheral nerve fibers and increase nerve functionality. Maximizing the health of remaining fibers is one of the best ways to prevent further degeneration and reduce neuropathy symptoms.

Peripheral nerve electrical stimulation can be very helpful in treating diabetic neuropathy. Multiple studies have demonstrated significant reduction in neuropathic pain from electrical stimulation to the legs, using a wide variety of electrical modalities (5).

In your NeuroRescue Program we will often employ one or more electrical stimulation modalities in the treatment of your diabetic neuropathy. One such modality involves somatosensory evoked potential stimulation, which uses repetitive polarizing electrical stimulus to activate peripheral nerves. Another device we use is called the Rebuilder, which uses several simultaneous currents to stimulate the entire affected sensory field of a specific nerve. Electrical stimulation is safe, painless, and effective. There are different indications for various types of electrical therapy, with the modalities employed tailored to the specifics of your case.

We may employ additional therapies, such as laser photobiomodulation. Both low-level and high-intensity laser therapy has been shown to be effective in controlling pain from diabetic neuropathies (14, 15).

We may also employ other advanced therapies, such as transcranial magnetic stimulation to reduce neuropathic pain (16), or hyperbaric oxygen therapy to improve nerve and tissue healing (17).

We may employ supplementation strategies to improve peripheral nerve regeneration. Substantial evidence exists for the use of antioxidants like alpha-lipoic acid, and flavinoids like luteolin and quercitin in the treatment of diabetic neuropathy (19).

As the central changes in visual and vestibular systems that develop with diabetes can conspire with your loss of sensation from your diabetic neuropathy, we put all of our patients through some form of vestibular rehabilitation and gait retraining to reduce their fall risk and prevent injury (18).

Every nervous system is different, and so is every NeuroRescue Program. We do not take a cookie-cutter approach to complicated neurological conditions. Your protocol will be determined by the specifics of your neurodiagnostic findings and the unique factors of your case.

How Does the NeuroRescue Program Work?

We design your unique NeuroRescue Program to be among the most comprehensive diagnostic and therapeutic protocols available today. We create individual NeuroRescue Programs based on a comprehensive analysis of every relevant neurological system and pathway, using gold-standard, cutting edge neurodiagnostic technologies and examination procedures and state-of-the-art therapies.

We begin with your Discovery Day, wherein we perform a comprehensive history of not only your condition, but your life on a timeline. This allows us to dive deeply into your case and see all of the factors that led to where you are now. It helps us uncover hidden problems and associated conditions that may be making it difficult for you to move your recovery forward.

Our examination allows us to identify the areas and pathways of your brain and peripheral nerves that are involved in your diabetic neuropathy. In all of our cases of assumed peripheral neuropathy, we begin by making certain that there are no central nervous system factors contributing to your symptoms. We do this by precisely quantifying the function of your visual, vestibular, and proprioceptive systems through computerized analysis of your eye movements, your inner ear reflexes, and your balance in a host of different sensory conditions.

We employ technologies including Videooculography and Saccadometry to measure several classes of eye movements. We use Video Head Impulse Testing to measure the function of your inner ear, and Computerized Dynamic Posturography to assess your balance in different sensory conditions.

We use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and perception of vertical in a virtual reality environment.

We combine all of this with a comprehensive physical and neurological examination of your sensory, motor, autonomic, and cognitive systems. We review any relevant laboratory testing, radiological imaging, and prior neurodiagnostic testing, and integrate that information with our findings.

We use this information to identify which parts of your nervous system are working properly, which systems are struggling, and the precise point at which your systems fatigue.

We can then design a NeuroRescue Program that is unique and specific to your brain, and yours alone. Your NeuroRescue Program works to rejuvenate and reintegrate the damaged neurons and pathways in your central and peripheral nervous systems. It works to improve energy, endurance, and functional capacity within your involved fragile systems.

We use our technologies and procedures to not only see what we need to address, but also when it is time to stop and let you rest. We address your impaired neurological function from multiple angles of therapy, and provide metabolic support to improve neurological recovery.

While we cannot bring back neurons that have been lost, your NeuroRescue Program allows us to take the pathways that remain and maximize their efficiency and endurance. And by focusing on the integration of systems, we can do more than just get pathways working better, we can get them working together again. This gives us our best opportunity to return you to living a healthy, vibrant, and fulfilling life.

Your Next Best Step:

Living with diabetic neuropathy can be challenging, but there is hope for symptom management and recovery of function. To see if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.

And remember, it’s never too late to start getting better.