Definition and Overview
Hand numbness is a symptom of paresthesia such as numbness, numbness, tingling, or burning in the hands or fingers. Since it is not a single disease but a symptom caused by various causes, accurate identification of the cause is the key to treatment.
Numbness in the hands is one of the most common complaints encountered in neurology outpatient clinics. The prevalence of carpal tunnel syndrome, the most representative cause, was reported to be approximately 3.8% of the general population. Numbness in the hands due to cervical radiculopathy occurs in approximately 83 people per 100,000 people.
Most hand numbness is caused by peripheral nerve compression and improves with appropriate treatment. However, if sudden unilateral hand numbness is accompanied by speech impediment or facial paralysis, it may be a precursor to a stroke, so immediate emergency response is required.
cause
The causes of hand numbness are divided into peripheral nerves, cervical spine, systemic diseases, autonomic nerves, and cerebrovascular diseases depending on the lesion area.
peripheral nerve compression
It is the most common cause. Physical pressure occurs in the narrow passageway through which the nerve passes.
- Carpal tunnel syndrome: The median nerve is compressed within the carpal tunnel of the wrist, causing numbness in the radial half of the thumb, index, middle, and ring fingers. It occurs in approximately 3-6% of the adult population and is three times more common in women than in men.
- Cubital tunnel syndrome: The ulnar nerve is compressed inside the elbow, causing numbness in the ulnar half of the ring finger and little finger. It is the second most common upper extremity compressive neuropathy after carpal tunnel syndrome.
- Guyon canal syndrome: Compression of the ulnar nerve in the ulnar nerve canal at the wrist.
cervical spine disease
When a nerve root is compressed in the cervical spine, numbness appears in the area controlled by that nerve.
- Cervical disc herniation: When disc herniation of the 6th or 7th cervical vertebrae, numbness occurs in the middle and ring fingers. When cervical vertebrae 5-6 are herniated, the thumb and index finger are numb.
- Cervical spinal stenosis: Due to degenerative changes, the spinal canal narrows and nerve roots are compressed. The frequency increases in people over 50 years of age.
- Posterior longitudinal ligament ossification: The cervical posterior longitudinal ligament becomes hard like bone and puts pressure on the spinal cord.
systemic disease
If numbness appears symmetrically in both hands, a systemic disease is suspected.
- Diabetic peripheral neuropathy: Peripheral neuropathy occurs in approximately 50% of diabetic patients. It usually shows a glove-sock type distribution starting from the fingertips and toes and gradually progressing upward.
- Hypothyroidism: Myxedema causes the tissue around the nerves to swell, putting pressure on the nerves.
- Vitamin B12 deficiency: Peripheral neuropathy occurs when there is a lack of vitamin B12, which is essential for the production of nerve myelin sheath.
- Rheumatoid Arthritis: Joint inflammation and swelling can put pressure on surrounding nerves.
autonomic nervous system abnormalities
If there is an abnormality in blood flow control in the hand due to dysfunction of the autonomic nervous system, the hand may become cold or change color along with numbness.
- Raynaud's phenomenon: Due to cold or stress, the blood vessels in the fingers contract excessively, causing the fingers to turn white and cause numbness.
- Small fiber neuropathy: Damage to fine sensory and autonomic nerve fibers causes burning, numbness, and abnormal sweating.
cerebrovascular disease
When blood flow is disrupted in the sensory areas of the brain, sudden numbness in the hands appears.
- Stroke: Characterized by sudden tingling or numbness in one hand or arm. It may be accompanied by speech impairment, facial paralysis, and walking difficulties.
- Transient ischemic attack: Stroke-like symptoms appear and disappear within 24 hours. This is a warning sign of a stroke.
symptoms
The pattern and area of hand numbness appear differently depending on the causative disease.
Classification by part
- Numbness in the thumb, index finger, and middle finger: in the median nerve area, carpal tunnel syndrome is suspected first.
- Numbness in the ring finger and little finger: In the ulnar nerve area, consider cubital tunnel syndrome or Guyon's canal syndrome.
- Numbness in the fingertips (glove type): If it occurs symmetrically on both sides, diabetic peripheral neuropathy or vitamin deficiency is suspected.
- Numbness in the entire finger + arm: There is a high possibility of cervical nerve root compression.
- Sudden numbness in one hand and arm: Cerebrovascular disease must be diagnosed.
Classification according to accompanying symptoms
- Numbness that gets worse at night: This is a typical symptom of carpal tunnel syndrome.
- Numbness that changes with neck movement: This suggests cervical disease.
- Accompanied by color changes in the hands (pale, blue): Suspect vascular or autonomic causes.
- Accompanied by muscle weakness: Nerve damage has progressed and early treatment is required.
Signs of Dangerous Hand Numbness
In the following situations, you should visit the emergency room immediately:
- Suddenly, one hand and arm becomes numb and loses strength.
- One side of the face droops or becomes numb.
- Speech becomes slurred or speech is not understood.
- Accompanied by a sudden severe headache.
- Walking becomes unstable.
These symptoms are typical signs of stroke. For stroke, thrombolytic medication can be administered within 4.5 hours after symptom onset, and the sooner treatment is started, the better the prognosis. Be sure to record the time the symptom occurred and call 119 immediately.
If numbness in both hands rapidly spreads upward over several days and is accompanied by weakness, prompt specialist evaluation is needed to assess for Guillain–Barré syndrome and other causes.
diagnosis
Diagnosis of hand numbness is carried out step by step through history taking, physical examination, electrophysiological testing, and imaging tests.
history taking
Systemically check the point of occurrence, area, pattern, aggravating factors, and accompanying symptoms of numbness. Occupation, repetitive movements, presence of underlying diseases such as diabetes, and medications taken are also identified.
Physical examination and provocation tests
- Phalen test: If numbness occurs when holding both wrists bent for 60 seconds, this suggests carpal tunnel syndrome.
- Tinel sign: Tap the carpal tunnel area of your wrist to see if it causes numbness.
- Spurling test: If arm numbness occurs when the neck is extended or rotated, it suggests cervical radiculopathy.
- Sensory testing: Infers damaged nerves by mapping areas of decreased sensation to light touch, pain, and vibration.
Electrophysiological testing
- Nerve conduction study: Measures the conduction velocity and amplitude of the median and ulnar nerves. It is a standard test for diagnosing carpal tunnel syndrome, and its sensitivity is reported to be approximately 85-90%.
- Electromyography: A needle electrode is inserted into the muscle to evaluate the extent and progress of nerve damage.
imaging test
- Cervical spine MRI: It is essential for identifying cervical spine lesions such as disc herniation and spinal stenosis.
- Ultrasound: In carpal tunnel syndrome, the degree of swelling of the median nerve can be checked in real time.
- Brain MRI/MRA: Performed when cerebrovascular disease is suspected.
blood test
Systemic diseases are diagnosed by testing glycated hemoglobin, fasting blood sugar, thyroid function, vitamin B12, folic acid, rheumatoid factor, and erythrocyte sedimentation rate.
treatment
Treatment for hand numbness varies depending on the cause of the disease.
Carpal Tunnel Syndrome Treatment
In mild to moderate cases, conservative treatment is given priority.
- Wrist braces: They are especially effective when worn at night, and studies have shown improvement in symptoms in approximately 70% of patients.
- Steroid injection: Temporary symptom relief can be expected with steroid injection into the carpal tunnel.
- Carpal tunnel decompression: Surgery is considered if the patient does not respond to conservative treatment or is accompanied by muscle atrophy. The success rate of surgery is reported to be approximately 75-90%.
Cervical spine disease treatment
- Drug treatment: Use anti-inflammatory painkillers and neuropathic pain drugs (gabapentin, pregabalin).
- Physical therapy: Perform cervical traction, manual therapy, and exercise therapy.
- Epidural steroid injection: Relieves symptoms by reducing inflammation around nerve roots.
- Surgical treatment: If neurological symptoms progress due to severe disc herniation or spinal stenosis, surgery is considered.
treatment of systemic diseases
- Diabetic neuropathy: Strict blood sugar control is key. There is a study that shows that keeping glycated hemoglobin below 7% reduces the risk of developing neuropathy by about 60%.
- Hypothyroidism: Treated with thyroid hormone replacement therapy.
- Vitamin B12 deficiency: Supplement with vitamin B12 orally or by injection.
Autonomic nerve-related treatment
- Drug treatment: Calcium channel blockers can be used for vasoconstriction disorders.
- Stellate ganglion block: Improves blood flow abnormalities caused by sympathetic nerve hyperactivation.
- Heart rate variability (HRV)-based autonomic nerve control: Assess autonomic imbalance and provide personalized treatment.
Cerebrovascular disease treatment
If stroke is confirmed, acute thrombolysis and thrombectomy are performed, and then antiplatelet or anticoagulant drugs are administered to prevent recurrence.
life guide
Daily management along with treatment of the cause helps control symptoms and prevent recurrence.
wrist care
- When working on a computer, keep your wrists in a neutral position and use a wrist rest.
- Stretch and rest your wrist for 5 minutes every hour.
- Wear dustproof gloves when using vibrating tools.
posture management
- Avoid lowering your head for long periods of time.
- Set the monitor at eye level and avoid bending your neck excessively.
- Adjust the pillow height appropriately to reduce the burden on the cervical spine.
full body health care
- Diabetic patients manage their blood sugar within the target range.
- Regular aerobic exercise helps improve peripheral blood circulation.
- quit smoking Smoking constricts peripheral blood vessels and worsens numbness.
- Excessive alcohol consumption can cause peripheral nerve damage, so refrain from drinking alcohol.
Symptom observation
- Record the area, frequency, and duration of numbness and provide it at the time of treatment.
- If new muscle weakness or muscle atrophy appears, visit a specialist early.
- If you experience sudden unilateral numbness and paralysis, go to the emergency room immediately.