Your nervous system is the line of communication between your brain and every bone, muscle, and organ in your body. It is responsible for all actions that take place within the body, from the nerve impulses that make your heartbeat, to the reflex that makes you immediately retract your hand from a hot stove, and everything else in between.
When the nervous system functions normally, you can easily take it for granted and not give much thought to the complex inner-workings that are taking place every second. But as with every other body part and system, problems can occur.
The nervous system is vulnerable to a wide variety of disorders, which can affect either the central nervous system (the brain and spinal cord) or the peripheral nervous system (everything else), or both. Nerves can be damaged by many possible causes, including trauma, infection, structural issues, degeneration, or autoimmune disorders. And the result of this damage depends entirely on the part or parts of the nervous system affected, which may lead to a range of potential symptoms. These can include problems with movement, speech, or breathing, as well as memory and mood.
A selection of the most common nervous system disorders
Below are some of the most common nervous system issues (also known as neurological disorders) and how each one affects the body.
Peripheral nerve problems are common and often treated in outpatient clinics.
- Cervical radiculopathy: occurs when one of the nerve roots in the neck is compressed or pinched where it branches away from the spinal cord, which is caused by any condition that injures or irritates these nerves. Symptoms may include a burning pain that starts in the neck and travels down the arm, upper back, and/or shoulders, along with weakness, numbness, and/or tingling in the fingers.
- Lumbar radiculopathy: occurs when a nerve root in the lower back is compressed or pinched when it branches away from the spinal cord, which is due to injury or irritation of these nerves; symptoms include pain, numbness, weakness, and/or tingling that radiates down the leg and sometimes into the foot
- Piriformis syndrome: a rare condition that occurs when a muscle in the buttocks (the piriformis) puts pressure on the sciatic nerve, which may be due to a spasm of this muscle; the most symptoms are tenderness in the buttocks and pain that travels down the back of the thigh, calf, and foot (sciatica).
- Carpal tunnel syndrome: a common condition caused by pressure on the median nerve, which runs the length of the arm and through a passage in the wrist called the carpal tunnel; symptoms usually start with a burning or tingling sensation, but eventually pain, weakness and/or numbness develop in the hand and wrist, and then radiate up the arm
- Other nerve entrapments: a number of other conditions also result when a single nerve is compressed or squeezed, such as cubital tunnel syndrome, Guyon’s canal syndrome, radial nerve compression syndrome, and thoracic outlet syndrome; symptoms vary depending on the diagnosis, but typically include aches and pains, tingling or numbness, weakness, and reduced flexibility
Conditions that Affect the Central Nervous System.
- Stroke: the fifth leading cause of death and one of the leading causes of disability in the U.S.; it occurs due to bleeding or the obstruction of blood flow in the brain; symptoms include trouble walking, speaking, and understanding, and possibly paralysis or numbness in the face, arm, or leg
- Ischemic: accounts for the majority of strokes; caused by blockage of an artery (or rarely a vein) in the brain, which affects blood flow to part of the brain
- Hemorrhagic: only accounts for about 13% of strokes; occurs when a blood vessel in the brain ruptures and bleeds, which deprives brain cells and tissues of oxygen and nutrients
- Parkinson’s disease: a progressive disorder (meaning it gets worse over time) caused by the loss of brain cells that make dopamine, a neurotransmitter that helps the body perform smooth and coordinated muscle movements; symptoms include tremors, trembling, stiffness or rigidness, and/or slowness of movements
- Multiple sclerosis: an autoimmune disorder, which means the body attacks its own healthy cells because it accidentally identifies them as foreign invaders; in multiple sclerosis, a substance called myelin (a fatty tissue that surrounds and protects nerves) is destroyed in many areas of the body, which leads to the formation of scar tissue called sclerosis; symptoms range widely but can include muscle weakness, numbness, stiffness, trouble with coordination, and fatigue
- Guillain-Barre syndrome: a rare autoimmune disorder in which myelin and other parts of the peripheral nervous system are mistakenly attacked, which prevents nerves from being able to properly send messages to and from the brain; the first symptom is usually weakness or a tingling sensation in the legs, which tends to come on rapidly and may spread to the upper body; symptoms may get worse, and may also include fatigue, pain, and loss of reflexes
- Myasthenia gravis: another autoimmune disorder that affects the communication between nerves and muscles throughout the body; symptoms include weakness in the arms, legs, and neck, difficulty swallowing, shortness of breath, blurred or double vision, and drooping of one or both eyelids
- Traumatic brain injury: sudden damage to the brain caused by a blow or jolt to the head, which can range from a mild concussion to severe brain damage; symptoms include headache, dizziness, nausea, lightheadedness, confusion, thinking, or memory issues, and behavior or mood changes
- Spinal cord injury: damage to any part of the spinal cord or nerves at the end of the spinal canal, which can result from car accidents, falls, violence, and sports-related trauma; symptoms include headache, numbness or tingling, an inability to move the arms or legs, difficulty walking, and pain or stiffness in the neck