Peripheral neuropathy is a term used to describe conditions where the peripheral nervous system, which includes all the nerves outside the brain and spinal cord, becomes damaged. This affects about 2% of people overall, but it increases to around 8% in those over 55.
Diabetes is the leading cause of peripheral neuropathy, usually starting with symptoms in the feet in a symmetric pattern. Treatments generally focus on tackling the root cause and relieving pain with medications.
Peripheral neuropathies come in various forms. Motor nerves help you move by sending signals from your brain to your muscles, while sensory nerves send sensation information back to the brain. Typically, both sensory and motor nerves are impacted, but sensory problems often take center stage. However, there are rarer types that may affect only one set of nerves.
Some neuropathies affect autonomic nerves, which control information flow between your internal organs. They can also be categorized by the size of affected nerve fibers: large fibers handle motor and sensory info, while small fibers deal with pain and temperature sensations.
In “length-dependent” neuropathy, the farthest parts of the nerves from the brain get affected first. This means symptoms often start in the toes and feet before gradually spreading up the legs symmetrically. Other types, like chronic inflammatory demyelinating polyneuropathy (CIDP), are “non-length dependent” and have different patterns, causing progressive weakness and numbness in limbs.
Mononeuropathies affect a single nerve, like ulnar neuropathy affecting the ulnar nerve at the wrist, resulting in localized pain and weakness. Conversely, polyneuropathies impact multiple nerves.
Neuropathies can be acute or chronic. Chronic types develop and worsen slowly, but acute ones, like Guillain-Barré syndrome, can come on quickly and are often inflammatory. Treating inflammatory neuropathies often requires a different approach.
Typically, peripheral neuropathy follows a chronic, length-dependent, non-inflammatory pattern, affecting motor and sensory nerves with sensory issues like tingling or numbness being prominent. Muscle weakness usually impacts the extremities—hands and feet—making fine motor movements difficult.
In diabetic neuropathy, symptoms often start in the feet and progress upward, possibly involving hands as symptoms reach the knees. Tingling and numbness are common, but weakness is less of an issue. People with diabetic neuropathy might not feel pain but can suffer serious injuries due to reduced sensation, sometimes even leading to amputation if neglected.
On the other hand, Charcot-Marie-Tooth disease—a common genetic neuropathy—primarily affects movement, causing weakness or paralysis in feet, lower leg muscles, and hands with minimal sensory issues.
Peripheral neuropathy stems from damage to the peripheral nervous system. Besides diabetes, which affects nearly half of diabetic individuals, other causes exist. Unfortunately, in about 25% of cases, the cause remains unknown.
Diagnosing peripheral neuropathy often involves a detailed medical history and a physical exam to uncover symptoms’ nature and progression. When symptoms align with known patterns, like in diabetic neuropathy, identifying the cause is straightforward. Further tests like blood work and nerve tests might be required for atypical cases.
Electromyography (EMG) and nerve conduction studies help gauge the electrical activity in muscles and nerves, providing deeper insights for diagnosis.
Treatment focuses on identifying and addressing the neuropathy’s cause. Sometimes symptoms resolve once the cause is managed, but some issues may persist. Pain management is crucial, with topical medications occasionally providing relief. Different subtypes might need specialized treatments, like immune-suppressing medications for inflammatory neuropathies.
While not all neuropathy cases are preventable, diabetes management is key—maintaining regular blood sugar levels can stave off neuropathy onset. Collaborating with an endocrinologist can help manage diabetes better and reduce related risks, like retinopathy and nephropathy, which accompany diabetic neuropathy because of poor diabetes control.
For most, peripheral neuropathy, though sometimes uncomfortable, is manageable. By controlling blood glucose, especially in minority groups facing higher complication rates, symptoms can be prevented from worsening. Proper foot care, including regular monitoring and immediate treatment of any injuries, is essential for those with reduced foot sensation.
