NUMBNESS AND TINGLING IN THE ARM
Numbness means decreased, and tingling unusual skin sensation. In this article, numbness and tingling in the arm, shoulder, hand or fingers are described. Read about numbness in both arms (hands) AND legs (feet).
Picture 1. Arm dermatomes
(A dermatome is a skin area, innervated by a single spinal nerve)
EVERYDAY CAUSES OF ARM NUMBNESS
Pressure Upon the Arm
Pressure upon the arm nerves or vessels causing numbness, tingling or temporary paralysis of the arm may result from:
- Sleeping with the hand under the head
- Sitting with the arm hanging over the back of a chair
- Wearing straps or carrying a bag or rucksack
- Inflated cuff during measuring blood pressure
Raising the Arms Above the Level of the Heart
Keeping the hand(s) above the level of the heart during work or sleep can prevent appropriate blood perfusion of the hands, and cause numbness, tingling or partial paralysis of the hand(s) within few minutes.
In cold weather, narrowing of the arteries in the hands and fingers can prevent appropriate blood supply and thus numbness, tingling, pain or temporary paralysis of the hands and fingers.
DISORDERS OF THE NECK (CERVICAL) SPINE
Cervical Disk Syndrome
Degenerative disc disease (DDD) or injury, like hyper-extension injury in car accidents (head moves rapidly toward the back), can result in bulging or herniated disc(s) pressing upon the cervical (neck) spinal nerves, thus causing symptoms of cervical disc syndrome:
- Position/movement dependent pain, tingling or numbness in the neck, shoulders, upper back, arm, hand or fingers (when the roots of cervical spinal nerves are compressed)
- Stumbling gait, difficulty with fine hand moves, tingling in the body or legs (when the cervical spinal cord is compressed)
Symptoms can appear immediately after the injury, or develop slowly over the weeks or months. Diagnosis is made by a CT or MRI of the neck spine. Therapy includes immobilization, cold therapy followed by heat therapy, cervical traction, analgesics, muscle relaxants, physical therapy or surgical decompression of the nerve roots or spinal cord.
Cervical spondylosis is an age-related deformation of the cervical spine; deformed vertebra or discs can press upon the spinal cord or nerve roots in the neck and cause chronic symptoms, like in the cervical disc syndrome (see above).
Disorders of the Brachial Plexus
The brachial plexus is formed by the cervical nerves C5-C8 and thoracic nerve Th1. The plexus extends from the lower part of the neck to the armpit. From brachial plexus all main nerves to the arm (axillary, musculocutaneus, ulnar, radial, and median nerve) arise.
Brachial Plexus Injuries
Most of brachial plexus injuries usually occur in car, motorcycle and sport accidents, during birth, or in bullet or knife injuries. Symptoms and prognosis depend on the nerves involved and extent of an injury: nerve stretching, scar tissue (neuroma), partial or complete nerve rupture or tearing of the nerve from the spinal cord. A limp or paralyzed arm, severe pain and numbness, especially in the neck and shoulders, and weak arterial pulses in the arm are main symptoms.
Some brachial plexus injuries may heal without treatment. Many children who are injured during birth improve or recover by 3 to 4 months of age. Treatment of brachial plexus injuries includes physical therapy and, if necessary, surgery.
Thoracic Outlet Syndrome
Thoracic outlet is the space between the collar bone (clavicle), first rib and corresponding ligaments through which nerves and vessels travel from the base of the neck toward the armpit. Thoracic outlet syndrome (TOS) results from a compression or extension of the subclavian artery or vein, or brachial plexus (nerves), commonly occurring in motorbike accidents, athletes, swimmers, weight lifters, etc. Symptoms include:
- Muscle wasting at the base of the thumb, numbness, feeling of pins and needles, or pain in the shoulder, armpit, arm or hand (when nerves are compressed)
- Pale, cool arm with weakened arterial pulse in the arm, numbness and pain (when vessels are compressed)
Radiation-Induced Brachial Plexopathy
Radiation-induced damage of the brachial plexus can follow radiotherapy of the chest, axillary region, thoracic outlet or neck. Symptoms may appear months to years after radiation therapy and include numbness, swelling, weakness or pain in the arm.
Broken Shoulder Blade
Shoulder blade (scapula) is the bone in the upper back that connects the collar bone (clavicle) and arm bone (humerus). Broken shoulder blade, usually from a car or motorbike accident, can result in pain, swelling, bruising or deformation of the shoulder blade area, and weakness, numbness or tingling in the shoulder or arm.
Broken Arm, Wrist, Hand or Finger
Symptoms of broken arm (the arm bone - humerus, elbow, and bones of the forearm – radius and ulna) include:
- Severe pain increasing with arm movement
- Obvious deformity, swelling, tenderness and bruising over the site of bone fracture
- Stiffness or inability to move your arm, hand or finger
- Weakness, numbness or tingling in the arm, hand or fingers
Cubital Tunnel Syndrome or Ulnar Neuropathy
The ulnar nerve arises from the brachial plexus in the neck and travels under the collar bone, downside along the inner side of the upper arm, behind the inner part of the elbow (Latin cubitus), where it can be felt as a “funny bone” and then down to the wrist, hand and little and ring finger. Ulnar nerve entrapment usually results from an elbow injury or constant pressure upon the elbow, like in cyclists or typists. Symptoms, known as cubital tunnel syndrome, include:
- Pain on the inner side of the elbow or electric shock sensation after touching the elbow
- The hand, ring and little finger are numb and falling asleep, especially after bending the elbow
- Limited movements of the ring and little finger (“handlebar palsy” in cyclists)
- Hand (on the little finger side) sensitivity to cold
Prevention of ulnar nerve entrapment is by avoiding excessive elbow use. Treatment includes special arm exercises, anti-inflammatory drugs, like ibuprofen, and wearing an elbow splint.
DISORDERS OF THE SPINAL CORD AND BRAIN
Multiple sclerosis is a disease of an uncertain cause affecting the nerve tissue of the spinal cord, brainstem or brain. Symptoms can appear suddenly or gradually, “travel” among various body parts and include: numbness or tingling in one or both arms (or any other body part), blurred or double vision or blindness, weak or paralysed limbs, problems with urinating or defecating, difficulty maintaining balance, tiredness, etc. Symptoms can last from few weeks to several months, disappear completely and appear again, and, in general, worsen with time.
Diagnosis is with MRI of the brain and spinal cord, and examination of cerebrospinal fluid obtained by lumbar punction. Apart from treating symptoms, there is no treatment for multiple sclerosis at the time.
ACUTE BRACHIAL NEURITIS
Acute brachial neuritis is a rare, supposedly autoimmune inflammation of brachial plexus, occurring at any age, but primarily in young men. Symptoms include severe pain in the upper arms and shoulders, followed by numbness and weak reflexes; the disorder resolves in few months on its own.
Carpal Tunnel Syndrome (CTS)
Carpal tunnel syndrome (Latin carpus = wrist) is a painful condition of the wrist, hand and fingers, caused by repetitive use of the wrist, or swelling of the tissues in the wrist, resulting in a pressure upon the median nerve. CTS is a common problem in assembly line workers, computer workers, musicians, mechanics, tennis players, etc. Bone spurs in rheumatoid arthritis, or fluid in hypothyroidism, kidney disease or menopause may also press on the median nerve. Symptoms usually start gradually and include:
- Tingling or numbness in the thumb, index, middle and ring finger and related part of the hand
- Pain in the wrist, palm or forearm
- Difficulty grasping small objects or gripping
- Hand pain at night
Ganglion cyst (Greek ganglion = tumor, cyst = fluid filled sac) is a soft lump, usually appearing on the back of the hand in some people between 20-40 years of age. It is a noncancerous fluid filled sack arising from the tendon sheets or capsule of the joint from an unknown reason. Ganglion cysts may not be always seen from the outside. Gymnasts often have them. Symptoms include:
- A soft lump or lumps of various size (may exceed an inch), on the back of the hand, inner side of the wrist, base of the finger, or on the last finger joint.
- Pain or numbness in the wrist, hand or finger(s)
DISORDERS OF FINGER ARTERIES
Raynaud’s disease is a painful finger condition due to spasms in the finger arteries. Disease may also affect toes or, rarely, nose, ears, lips and nipples. The cause is not known. Symptoms are triggered by cold (even short term cold like taking something from a freezer) or strong emotions, and appear in the following sequence:
- Fingers (one, more or all in one or both hands) become pale, numb or cold due to lack of blood flow, then bluish due to a lack of oxygen, then red, with throbbing pain and tingling as blood returns to the affected area.
- Attacks can occur daily, weekly or occasionally and can last from less than a minute to several hours, usually about 15 minutes. Different areas can be affected at different times. Severe, although rare, attacks can result in finger sores or tissue death (gangrene).
Raynaud’s phenomenon is a term used for the same finger symptoms as in Raynaud’s disease, when the cause is known. Causes include: connective tissue diseases, like scleroderma, systemic lupus erythematosus (SLE), Sjögren’s syndrome, dermatomyositis, and polymyositis, carpal tunnel syndrome, obstructive arterial disease, anti-hypertensive drugs, ergotamine (used for treating migraine), chemotherapeutic medications, etc.
In workers exposed to vinyl chloride, using vibrating tools, typists and pianists, Raynaud’s phenomenon also commonly occurs.
DIAGNOSIS OF ARM NUMBNESS OR TINGLING
History of arm numbness. Knowing an exact time course of tingling or numbness, and eventual arm weakness, head or legs involvement, history of arm or neck injuries, repetitive elbow or wrist use, reactions to cold, hypothyroidism, diabetes, menopause may give a strong evidence about the cause.
Neurological examination. Testing of sensitivity of a particular arm dermatome can reveal which nerves are involved.
Imaging. X-ray may reveal arthritis in the neck spine, or a broken arm bone. Myelography can reveal herniated disc or narrowed spinal canal. MRI and CT show soft tissues like tumors.
Electromiography (EMG) and nerve conduction studies can show the nature of the nerve damage. Together with imaging they are important to evaluate the extent of brachial plexus injury.
Blood tests can reveal diabetes, abnormalities in serum levels of sugar (diabetes), calcium, potassium, sodium, magnesium, vitamins B6 or B12, thyroxine (hypothyroidism), sex hormones (menopause).
Cold simulation test can reveal Raynaud’s disease or phenomenon.
TREATMENT OF ARM NUMBNESS OR TINGLING
Firstly, the cause of numbness should be treated if possible.
Non-steroid anti-rheumatic drugs like ibuprofen, or antidepressants, may relieve pain and numbness.
Rest and immobilization of the neck, shoulder, elbow, wrist, or the whole arm is sometimes necessary after an injury, or when joint movements contribute to nerve irritation, like in ulnar nerve entrapment or carpal tunnel syndrome.
Physical therapy may help when bones, articles and muscle tendons are involved. Physiotherapist may show you special exercises for each type of nerve disorder.
Effect of acupuncture, acupressure, TENS (Trans Cutaneous Nerve Stimulation) may be debatable. Certain ointments like capsaicin may temporarily relieve tingling, burning sensations.
PREVENTION OF ARM NUMBNESS OR TINGLING
The following may help to prevent arm and hand numbness:
- Avoid putting the arm over the chair back to prevent permanent injury of brachial plexus
- Avoid sleeping with the hand under the head, or with arms on the pillow
- Avoid using mechanical screwdrivers
- Do not rest your elbows on the desk for long periods of time, while working with a computer
- Wear warm gloves at low temperatures
- Brachial plexus (bartleby.com)
- Anatomy of the arm (frca.co.uk)