Nerve weakness, also medically known as neuropathy, is a widely used term to denote temporary or permanent nerve damage that may occur due to dysfunction of the brain and spinal cord or the nerves of the peripheral nervous system. It is more commonly known to affect people more than 65 years of age, however it can involve people of any age group. A large number of elderly people are affected every year, of which nerve weakness due to diabetes mellitus is the most common in India.

Although it is generally called nerve weakness, the nerves are not always the reason for the weakness. Sometimes the connection between the nerve and the muscle may be lost, or the nerve may function normally but the muscle that it is associated with may not function properly or the receptors from where the sensations are carried to the brain may be affected.

Types

Neuropathy can be classified based on multiple factors such as nature, locations, causes

Acute or chronic: in acute neuropathy symptoms occur suddenly while chronic neuropathy the symptoms occur over a significant period of time.

Central neuropathy: nerve weakness that occurs due to damage of the nerves that arise from the brain or the spinal cord. Eg. cranial nerves

Peripheral neuropathy: they arise due to involvement of the nerves outside the brain and spinal cord and tend to affect the nerves of the peripheral nervous system.

Autonomic neuropathy: it occurs due to damage to the nerves that control the day-to-day body functions like temperature control, blood pressure, bladder control etc.

Focal neuropathy: it is when a single nerve or one group of nerves are affected called mononeuropathy and are most frequently seen in diabetes mellitus.

Sensory or motor neuropathy: depending on the nature or type of nerves affected they can result in sensory loss with altered sensation or loss of function due to muscle weakness. Rarely combined neuropathy can also be seen where both sensation and motor functions are affected.

Proximal or distal neuropathy: proximal neuropathy affects nerves that innervate the muscles closer to the torso and may lead to weakness of the shoulders, thigh, or upper arm. Whereas distal neuropathy affects nerves of the muscle farther away from the torso resulting in weakness or hands or foot.

Causes & Risk factors

There are numerous causes or risk factors associated with nerve weakness and can differ based on the presentation of the nerve weakness in the elderly. They are

Diabetes mellitus is one of the leading causes of nerve weakness in people and is most commonly seen in people with long-term uncontrolled diabetes mellitus. It may affect any nerve in the body and may also be associated with the involvement of arteries and veins.

Vitamin deficiencies like vitamin B12, vitamin B6, vitamin E and thiamine.

Chronic alcoholism can also cause neuropathy due to malnutrition and thiamine deficiency

Congenital defects that affect nerve development or function

Infections like herpes, chickenpox, leprosy, syphilis, Lyme's disease, HIV, etc

Autoimmune conditions can affect the nerves directly like in SLE, sjogrens syndrome etc or may result in demyelinating polyneuropathy like Guillain barre syndrome.

Traumatic events can result in fracture, mechanical nerve damage, or compression of the nerve leading to nerve weakness

Exposure to toxins or medications like lead toxicity, mercury, chemotherapy, medications for epilepsy and antibiotics can cause nerve weakness

Vascular disorders where nerve weakness occurs due to poor arterial supply like in blood clots or inflammation of the vessels.

Other chronic systemic conditions like kidney failure, liver dysfunction, and cancers are known to cause neuropathies.

Signs and Symptoms

A person with nerve weakness may have symptoms depending on the type, location, or duration of nerve damage. The most common symptoms seen are numbness, pins and needle sensation, reduced or altered feeling to touch, smell, vibrations, etc, pain or burning sensation, muscle weakness, loss of the bulk of the muscle called wasting, difficulty walking, or increase in falls and complete loss of function of a body part called paralysis. The other symptoms noticed may be difficulty urination, constipation, diarrhea, sexual dysfunction, low blood pressure, dizziness or light-headedness.

Diagnosis

Like most medical conditions the diagnosis begins with a thorough history taking and physical or neurological examination by your doctor, followed by which few basic tests are advised. Blood tests are done to evaluate the patient for vitamin deficiency, toxins, sugar levels, thyroid levels, and electrolyte abnormalities. Imaging like an MRI scan is done to watch for nerve compression or structural defects. More specific tests to assess the nerve function are nerve conduction study, nerve electromyography or very rarely nerve biopsy.

Treatment

The main aim in the treatment of neuropathy especially in the elderly is symptomatic management. The symptoms of nerve weakness can sometimes be very painful and troublesome affecting the quality of life. Medications to manage the symptoms, particularly increased sensitivity to pain, and treatment of vitamin deficiencies, thyroid dysfunction, electrolyte abnormalities, and uncontrolled blood sugar levels are very vital for the overall improvement. Surgery may also be helpful in certain conditions like nerve compression or spinal cord involvement.

Recommendations from Be Well

Nerve weakness in the elderly may be distressing and requires proper medical intervention at the earliest. Being aware of the small changes in one's body function and seeking proper medical guidance helps reduce the complications and the overall time for recovery. Although the resolution of all nerve weakness may not be possible, prevention of progression or worsening of symptoms are most definitely attainable. Many people with neuropathy generally tend to discontinue treatment within a few days as there is no significant improvement but it should be understood that improvement in nerve functions generally takes about weeks to months and hence it is advised to continue treatment patiently.