Types of Peripheral Neuropathies

Types of Peripheral Neuropathies

Types of Peripheral Neuropathies

Last updated 28th February, 2024

Last updated 28th February, 2024

Last updated 28th February, 2024

Peripheral neuropathy is a condition marked by the degeneration of peripheral sensory nerves that result from a complication of a certain disease or injury. Symptoms vary from patient to patient and include: tingling, numbness, hypersensitivity and intense, jarring pain in the extremities. For some, all sensation in the hands and feet are lost, often resulting in ulcers and amputation. The prevalence of peripheral neuropathy is 2% to 4% worldwide and 6% in the US alone.

An estimated 30 million Americans suffer from a type of peripheral neuropathy. There are over 100 different types of neuropathies. We are currently undergoing clinical trials for a lead drug aimed at treating diabetic peripheral neuropathy (DPN), chemo-induced peripheral neuropathy (CIPN) and HIV-PN (HIV-induced peripheral neuropathy). Our lead drug treats peripheral neuropathy, focusing on sensory polyneuropathy.

Types of Neuropathies

  • Motor neuropathy – Motor neuropathy affects the nerves that control the motor functions of our body, such as walking and talking.

  • Sensory neuropathy – Sensory neuropathy affects nerves that control how we feel and our sensations, such as pain, temperature and touch.

  • Autonomic nerve neuropathy – Autonomic nerve neuropathy affects the nerves that control our autonomic functions (functions that are not in our control), such as breathing and blinking.

  • Mononeuropathy – Mononeuropathy affects a single nerve or nerve group.

  • Polyneuropathy – Polyneuropathy affects multiple nerves at once in different parts of the body.

  • Combination neuropathy – Combination neuropathy is a mix of two to three different neuropathies.

Causes of Neuropathy
There are over 100 different types of neuropathies with symptoms that vary from patient to patient. We focus on the three main types: diabetic, chemo-induced and HIV-induced neuropathy.
Diabetes
Peripheral neuropathy is a condition that involves damage to the peripheral nervous system. Our peripheral nerves carry signals to and from our central nervous system. Hence malfunctioning of these nerves causes disruption and affects how the body reacts to reflexes and other stimuli, like pain and temperature.
Diabetic peripheral neuropathy is a progressive disease that involves pain, loss of sensation and weakness. However, a proper clinical examination may identify early signs without the presence of any symptoms. About 60% to 70% of diabetic patients are known to suffer from peripheral neuropathy. If not treated in time or managed well, it can lead to lower limb amputations. Each year, nearly 54,000 diabetics undergo amputations, 75% of which are preventable.
Symptoms
Symptoms develop gradually and can go unnoticed until they cause serious damage. If you notice any slight change in your symptoms or condition, consult your physician.Nerve damage in diabetic neuropathy is caused due to high glucose levels. Diabetics are often recommended to maintain their blood glucose levels within a healthy range to prevent any further health complications. Symptoms can vary person to person but here are a few common ones:Numbness

Nerve damage can lead to loss of sensation in the limbs. Neuropathy patients often complain of lack of sensation. They may not feel any sensation in their legs while walking. Numbness may feel analogous to wearing a glove or sock. Besides numbness, patients also complain of a tingling or burning sensation.
Pain

Patients have described neuropathic pain as jarring, shooting and cramping. Sudden spurts of electrifying pain can cause a decrease in grip strength.Balance Issues
Numbness in the limbs can cause incoordination in muscles which would increase the frequency of balance issues. It can affect placement of legs which in turn leads to an unsteady gait.
Sensitivity
Nerve damage can lead to a reduced and or altered sense of temperature and pain. Surfaces at normal temperatures (room temperatures) can feel hotter or colder than usual. Bruises and wounds tend to also go unnoticed due to lack of sensation of pain.
Chemotherapy
Cancer treatments and chemotherapy can cause nerve damage that leads to chemo-induced neuropathy. These include platinum-based drugs, taxanes, Vinca alkaloids and Bortezomib. These drugs are commonly used to treat myeloma, breast cancer, ovarian cancer, lung, brain and testicular cancers. The frequency of chemotherapies and the potency of drugs increases the risk of neuropathy.
Symptoms
Symptoms present symmetrically and begin at the extremities of the body and continue upwards. Common symptoms include:Tingling sensationPainNumbnessWeaknessAbnormal sensation to stimuli, such as pain, pressure and temperature
HIV
Inflammatory neuropathy can be caused due to infections by viruses, such as human-immunodeficiency virus. As of 2020, approximately 37.7 million people around the world suffer from HIV. HIV is also known as “antiretroviral toxic neuropathy” and is found in 2% of people who suffer from peripheral neuropathy.
Other Causes of Neuropathy
Neuropathy can arise due to underlying conditions and can be managed by treating the given condition.Autoimmune disordersAutoimmune diseases are caused when an individual’s immune system attacks its own tissues. Nerve damage can be caused by such conditions that can lead to acute neuropathy. This can cause temporary or chronic neuropathy such as Guillain-Barre syndrome, an acute form of peripheral neuropathy while chronic inflammatory demyelinating polyneuropathy (CIPD) is a chronic form of neuropathy. Acute neuropathies are caused when the symptoms develop suddenly while chronic neuropathy is caused gradually.
Toxins
Long term exposure to certain toxins can cause peripheral neuropathy. Common toxins include arsenic, lead and mercury. These can be found in insecticides and solvents can be exposed due to an individual’s working conditions.Vitamin Deficiency and Alcohol AbuseVitamin E, B1, B6, B12 are necessary for proper functioning of nerves. Excessive alcohol intake can affect thiamine and other necessary vitamins that can in turn lead to neuropathy.Genetic DisordersThe inheritance of certain genes can also cause peripheral neuropathy. These neuropathies are passed down from the parent to the child. Charcot-Marie-Tooth (type 2A), is a form of peripheral neuropathy associated with axonal damage and sensory loss.Idiopathic CausesWhen the cause of neuropathy is unknown, it is termed as idiopathic neuropathy.
Physical and neurological exams.
These involve a healthcare provider looking for physical signs of peripheral neuropathy, including changes in your ability to feel sensations, muscle weakness, changes in your reflexes or trouble with walking and balance.
Lab, diagnostic and imaging tests.
There are no good tests to diagnose peripheral nerve damage. Skin biopsies can determine the number of nerves in the skin biopsy.What tests diagnose peripheral neuropathy?The most common types of tests for peripheral neuropathy rely on diagnosing the underlying cause, but generally cannot determine the health of the nerve itself:Blood tests. These can detect many problems, ranging from immune system problems to toxins and poisons, especially metals like mercury or leadElectromyogramNerve ultrasoundNerve conduction velocityNerve biopsy

How is peripheral neuropathy diagnosed?

Peripheral neuropathy is underdiagnosed as it is often ignored by most health practitioners who are unaware of the disease, or unable to accurately diagnose due to a lack of good diagnostic tools and treatments. Diagnosing peripheral neuropathy usually involves a combination of methods. These include:

  • Symptoms and medical history. Your healthcare provider will likely ask questions about your medical history and any recent symptoms or changes you’ve noticed. They may also ask about other medical conditions and factors, such as type 2 diabetes, and your nutrition, habits and lifestyle.

  • Physical and neurological exams. These involve a healthcare provider looking for physical signs of peripheral neuropathy, including changes in your ability to feel sensations, muscle weakness, changes in your reflexes or trouble with walking and balance.

  • Lab, diagnostic and imaging tests. There are no good tests to diagnose peripheral nerve damage. Skin biopsies can determine the number of nerves in the skin biopsy.

What tests diagnose peripheral neuropathy?

The most common types of tests for peripheral neuropathy rely on diagnosing the underlying cause, but generally cannot determine the health of the nerve itself:

  • Blood tests. These can detect many problems, ranging from immune system problems to toxins and poisons, especially metals like mercury or lead

  • Electromyogram

  • Nerve ultrasound

  • Nerve conduction velocity

  • Nerve biopsy

  • Genetic testing

  • Magnetic resonance imaging (MRI)

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