Introduction
Neuropathy refers to a condition that affects the peripheral nervous system (PNS), which consists of the nerves outside of the brain and spinal cord. It is characterized by damage or dysfunction of these nerves, leading to a variety of symptoms. The peripheral nerves are responsible for transmitting signals between the central nervous system (brain and spinal cord) and other body parts, including the muscles, skin, and internal organs.
Nerve damage can happen due to infections from various viruses, bacteria, and parasites. It can also be caused due to other reasons, such as
-
Chronic systemic diseases (hypertension and type II diabetes mellitus).
-
Autoimmune diseases (disorders in which the immune response of the body attacks its healthy cells).
-
Tumors.
-
Genetic conditions.
-
Vitamin and nutrient deficiencies (copper and vitamin B12 deficiency).
-
Medications and toxins.
How Do Bacteria Affect the Nervous System of the Body?
When bacteria enter the human body, they reside in the organs such as the intestines, respiratory tract, and genitourinary tract. There they release various toxins into the bloodstream, which are further carried to the brain and cause brain damage. These bacterial toxins can affect the transmission of signals between neurons resulting in problems with sensory and motor function leading to cognitive decline.
Which Bacteria Affect the Nervous System?
The various types of bacteria that show clinical symptoms by acting on the peripheral nervous system are as follows -
1. Campylobacter Jejuni - This bacteria causes food poisoning. It spreads through contaminated food and water and clinically presents as abdominal pain, diarrhea, and fever. Campylobacter jejuni has a strong association with the development of Guillain-Barre syndrome. Guillain-Barre syndrome is an autoimmune disorder characterized by flaccid paralysis (sudden weakening of the muscles) or paralysis (inability to move) along with reduced muscle tone. It is caused by due to demyelination of nerves (damage to the protective covering surrounding the nerves).
In peripheral neuropathy, the immune system of the body attacks the nerves. This leads to nerve damage and failure to transmit impulses to the brain, causing impaired motor function (weakness of muscles, numbness, or paralysis).
2. Corynebacterium Diphtheriae - This bacteria causes diphtheria, a severe bacterial infection that usually affects the nose and throat mucous membranes. The toxin produced by this bacteria can damage the nerves in the throat. The damaged nerves cannot transmit impulses to the brain, which causes a loss of function in the throat muscles. The nerves of the arms and legs also get inflamed, leading to weakness in the limbs.
The symptoms may present as follows -
-
Difficulty in breathing and swallowing.
-
The throat muscles may get paralyzed, and oxygen support might become necessary.
3. Brucella Bacteria - This bacteria causes a disease known as brucellosis, commonly affecting animals such as cows, pigs, sheep, goats, cattle, and dogs. It can also cause a flu-like illness in humans. Neurobrucellosis is the neurologic involvement of brucellosis in humans. The common neurological findings associated with this disease are -
-
Alterations in behavior.
-
Disorientation.
-
Muscle weakness.
-
Neck rigidity.
-
Sensorineural loss of hearing.
-
Severe cases may present as limb paralysis.
4. Clostridium Botulinum - The bacteria Clostridium botulinum causes botulism. This bacteria usually grows and produces the toxin botulin in areas without oxygen. Therefore, it most commonly harbors canned, processed foods and preserved foods.
The bacteria Clostridium botulinum produces a toxin called the botulinum toxin (neurotoxin) that interferes with the release of acetylcholine from the nerve endings. Acetylcholine is a neurotransmitter that transmits impulses from one neuron to another. These impulses are essential for motor functions or voluntary movements. The inhibition of acetylcholine release from nerve endings will cause muscle paralysis (inability to move).
5. Mycobacterium Tuberculosis - Mycobacterium tuberculosis is the causative agent for tuberculosis. This bacteria attacks the lungs and even other parts of the body, including the brain and spinal cord. Tuberculosis is a highly infectious disease. The following symptoms characterize it-
-
Cough lasting for more than three weeks.
-
Coughing blood.
-
Fever, chills, and night sweats.
-
Fatigue.
-
Chest pain.
Tuberculosis has many systemic and neurological complications. The bacteria spread toxins in the other organs and cause symptoms. The standard neurological complications of tuberculosis are -
1. Tuberculous Meningitis - Meningitis is the inflammation of the meninges (the outer covering of the brain and spinal cord). It is commonly seen in immunocompromised (patients with low immunity) individuals. Tuberculous meningitis may lead to various brain complications such as -
-
Cerebral ischemia causes a stroke (restricted or reduced flow of blood and oxygen supply to the brain).
-
A buildup of fluid between the skull and brain (subdural effusion).
-
Hydrocephalus (accumulation of fluid inside the skull potentially leading to brain swelling).
-
Seizures (uncontrolled involuntary movements of the body accompanied by loss of consciousness.
-
Hearing loss.
2. Intracranial Tuberculoma - An intracranial tuberculoma is a type of brain lesion or mass caused by tuberculosis (TB) infection. When tuberculosis bacteria reach the brain, the body's immune system tries to contain the infection by forming a mass or granuloma, which is called a tuberculoma. Tuberculomas can occur in various parts of the brain and can vary in size.
3. Spinal Tuberculosis or Pott’s Disease - It is a rare spinal infection that occurs as a tuberculosis complication. The source of this infection is out of the spine. The bacterial toxin spreads from the lungs through the blood and it is characterized by osteomyelitis (an infection in the bone) and infective arthritis (a painful joint infection).
4. Mycobacterium Leprae - It is also known as Hansen’s disease. The bacteria mycobacterium leprae is the causative agent of the illness - leprosy. This bacteria affects the nerves, skin, eyes, and nose lining and the nerve damage can even cause paralysis of the hands and feet. The following symptoms characterize this disease -
-
Discolored patches of skin are seen on the body and face.
-
Numbness of the affected areas of the skin.
-
Weakness and paralysis of the hands and feet.
-
Painless swelling or lobes on the face.
-
Painless ulcers on the soles of the feet.
How to Diagnose Bacteria-Induced Peripheral Neuropathy?
The diagnosis is mainly dependent on the symptoms experienced by the patient. The physician will record a detailed medical history of the patient and consider all the signs and symptoms to carry out further investigations which include-
-
A detailed neurological examination like sensory evaluation, motor evaluation, and reflexes.
-
Brain imaging scans such as MRI (magnetic resonance imaging) help detect brain injury.
-
Blood tests are done to detect the bacteria in the blood. An increase in the lymphocyte count is seen in bacterial infections.
How to Treat Bacterial Peripheral Neuropathy?
The treatment aims at managing the condition causing neurological symptoms. The following treatment modalities are adopted in treating various neuropathies -
-
Pain-relieving medications help in reducing inflammation and pain in the body.
-
Anti-epileptic medications for controlling seizures.
-
Topical creams for pain relief.
-
Physical therapy is indicated to improve motor function.
-
Surgery may be required in severe cases.
-
Lifestyle changes such as a healthy diet, exercise, and stress-free life are also necessary.
Conclusion
Bacterial infections affecting the nervous system can be treated effectively with medications and supportive care. It is essential to identify the symptoms early to avoid further cognitive decline. Prompt treatment by the doctor is critical in preventing other complications.
