Paresthesia

Whenever you keep your legs crossed for a long time or get your arm pinned under yourself while sleeping, you experience a tingling, “pins and needles” feeling in the limbs. This skin-crawling, itching, numb, tingling, burning, or prickling sensation is known as paresthesia. A loss of sensation in the skin is called numbness, and an unusual sensation in the skin is called tingling. Tingling is often described as tickling, pricking, skin-crawling, ant-crawling, pins-and-needles, and so on. Symptoms such as tingling, burning, itchiness, or numbness may occur simultaneously in restless leg syndrome. The most common occurrence of paresthesia is when a limb falls asleep and you feel a crawling sensation underneath the skin. People find this sensation odd and may become worried about it, but it is usually harmless. However, in certain cases, it can be a symptom of a more serious medical condition, which may require medical attention. When sustained pressure is placed on a nerve, paresthesia may occur. However, when the pressure is relieved, the sensation quickly fades away. Many times, chronic paresthesia is a symptom of an underlying medical condition, such as a neurological disease or traumatic nerve damage. Disorders that affect a person’s central nervous system, such as transient ischemic attacks, strokes, encephalitis, transverse myelitis, or multiple sclerosis, may cause paresthesia. Other possible causes include vascular lesions or tumors. Nerve entrapment syndromes can damage the peripheral nerves and cause pain along with paresthesia.

Facts about Paresthesia

Withdrawal from benzodiazepine may cause paresthesia, as the drug cessation may make the GABA receptors malformed.

Common sources of paresthesia are rheumatoid arthritis, psoriatic arthritis, and carpal tunnel syndrome.

If the central nervous system is damaged due to stroke or traumatic brain injury, such people may experience paresthesia.

Chronic paresthesia indicates a problem with the proper working and functioning of neurons, or it may indicate poor circulation.

Vitamin deficiencies, malnutrition, metabolic disorders like diabetes, hypoparathyroidism, and hypothyroidism, or mercury poisoning may cause paresthesia.

Nerves can be attacked by herpes zoster disease, which can cause numbness instead of pain.

Paresthesia and Dermatomes

The brain interprets the sensations we feel. The spinal nerves that arise from the spinal cord mediate the sensibility of the trunk, limbs, and back of the head. The sensitivity of the face is mediated by the trigeminal nerve, which arises from the brain stem. The single nerve root of the spinal or trigeminal nerve innervates the area of the skin called a dermatome. A doctor can determine the nerves affected from the distribution of abnormal skin sensations among dermatomes. 

This “pins and needles” feeling can affect any part of the human body, however, the most frequently affected limbs are the feet, legs, arms, and hands.

Paresthesia in itself is considered a symptom of certain medical conditions. It can be chronic or temporary, and the symptoms common to both include numbness, a cold feeling, burning, tingling, weakness, itching, foot drop, crawling sensation, limbs falling asleep, restless leg syndrome, ocular dysmetria, and muscular atrophy. Other symptoms of paresthesia may be related to an underlying condition.

However, in the case of chronic paresthesia, one may experience a throbbing pain, which can further cause clumsiness in the affected limb. Whenever paresthesia occurs in the feet or legs, it can be difficult or sometimes impossible for the person to walk even a few steps.

If a particular condition causes paresthesia, additional symptoms may be experienced. Paresthesia is usually painless and occurs without warning. The sensitivity of the affected area may be increased, but, eventually, it decreases again. Sometimes, tingling is incorrectly described as itchiness; the difference is itchiness provokes a person to scratch whereas tingling does not. Similarly, burning is a form of pain rather than tingling. When the arm or leg becomes temporarily numb or paralyzed, it is said that the arm or leg has fallen asleep.

If you experience any of these symptoms which are affecting your quality of life or pose persistent problems, you should see a doctor, as it might be a symptom of an underlying medical issue that requires treatment.

The most common cause of paresthesia is pressure on a nerve. When pressure is taken off the specific area, for example, when the legs are uncrossed, the tingling, itchy feeling goes away. However, in some cases, it does not go away easily or might come back on a regular basis. This is known as chronic paresthesia, and it is a sign of a serious medical condition like nerve damage. Usually, skin sensations are carried via peripheral sensory nerves from the skin through the spinal cord or to the brain via the trigeminal nerve and brain stem. If, at any level, there is a disorder of this neural pathway, it can cause paresthesia. Nerve damage can occur due to:

• A major accident: The resultant physical injury could cause damage to the nerves.

• A minor or major stroke: This cuts off the normal blood flow to the brain, causing brain nerve damage.
• Multiple sclerosis: This is a serious central nervous system disease that brings about a change in the way the body parts feel.
• Blood sugar: A diabetic disorder that is capable of damaging the nerve or nervous system over a prolonged period of time.
• A pinched nerve: A nerve in body parts such as the arms, shoulders, or neck that becomes pinched might be a result of overuse or injury.
• Sciatica: This is a serious medical condition related to the sciatic nerve, which goes from the pelvis to the buttocks and legs. In this condition, numbness and extreme pain occurs in the lower back or legs due to excessive pressure on the sciatic nerve, and usually happens during pregnancy.
• Carpel tunnel syndrome: This is a condition where the tunnel from the wrist to the lower palm becomes excessively narrow and causes numbness and pain in the fingers, hand, wrist, and forearm.
• Vitamin deficiencies: A vitamin B12 deficiency, especially, will cause nerve weakness, as it is an important vitamin to maintain nerve health.
• Certain medications: Chemotherapy especially results in nerve damage and irritation. Some antibiotics or anti-seizure and HIV medications can also cause paresthesia.

Other causes of paresthesia include migraines, alcohol abuse, neuropathy, malnutrition, menopause, dehydration, herpes, hypoglycemia, nerve irritation, heavy metal poisoning, auto-immune disorders, Lyme disease, neurological disease, anticonvulsant drugs, metabolic disorders, immune deficiency, hyperventilation, and brain tumor.

Transient paresthesia is temporary and may be caused by:

• Obdormition due to prolonged pressure on the nerve from crossing the legs, which results in numbness; as the pressure is relieved, it tends to disappear.
• Whiplash
• Hyperventilation syndrome
• Panic attack
• Dehydration
• Transient ischemic attack (also referred to as a “mini stroke”)
• Beta-alanine ingestion
• Seizures
• Raynaud phenomenon
• Insufficient blood supply to the legs 

Chronic paresthesia can be long-lasting or recurring. Its causes include:

• Brain, spinal cord, or peripheral nerve disorders: These include stroke, intra-cerebral hemorrhage, trauma, meningitis, encephalitis, herniated disc, pressure on the nerve, cervical spondylosis, repetitive motion, or prolonged neuralgia vibration.
• Circulatory disorders: These include atherosclerosis, angina pectoris, vasculitis, Raynaud disease, arterial occlusion, and vertebrobasilar circulatory disorders.
• Infections and post-infection syndromes: Such as infection from the herpes simplex virus, herpes zoster virus, arbovirus, canker sores, Guillain-Barre syndrome, rabies, and syphilis
• Metabolic and hormonal disorders: These include diabetes, menopause, abnormal calcium, potassium, or sodium levels in the blood, uremia, porphyria, and hypoaldosterone.
• Blood disorders: Such as thrombosis, polycythemia, leukemia, and thrombocytosis
• Connective tissue and autoimmune diseases: Such as systemic lupus erythematosus, Sjogren’s syndrome, pernicious anemia, and diabetes

If you experience persistent paresthesia without any obvious cause, go see your doctor and talk about your condition to receive appropriate treatment.

You should be ready to answer the following questions before going to the doctor:

• On which body parts do you feel tingling or numbness? Is it limited to one side? Describe the feeling: numbness, pricking, burning, itching, pins and needles, creeping,  etc.
• When did the unusual sensation appear? Is it permanent or transient? Is there a change in the sensation throughout the day?
• What triggers the sensation: exercise, sitting, stress, food, medication, or warmth?
• Are there any other symptoms in the affected area, such as pain, paleness, swelling, warmth, cramps, coldness, redness, or loss of muscle power?
• Have you had any other symptoms, such as a fever or headache?
• Do you suffer from any chronic diseases, such as diabetes or rheumatoid arthritis? Were you ever hospitalized for an injury? Thus far, what diagnoses have you had?
• Does your work require you to perform repetitive motions? Are you affected by constant vibrations? Are you exposed to certain chemicals, such as carbon monoxide or nitrogen dioxide?
• Are you anxious, or is there any kind of stress in your life?
• Do you drink alcohol or smoke? Are you on any kind of medication or drugs?

Be sure to provide your doctor with your complete medical history, and talk about any physical activity you regularly participate in that involves any sort of repetitive movements. You should also clearly mention any prescription or over-the-counter medications you are taking. All these will help the doctor understand your health condition and prepare a well-informed diagnosis.

Through diagnosis, the doctor aims to uncover any underlying medical condition causing the paresthesia sensations. Paresthesia can be either transient or chronic. Symptoms of hyperventilation or a panic attack may result in transient paresthesia and nerve irritation, while neuropathy, poor circulation, and many other conditions may cause chronic paresthesia. Paresthesia does not cause any long-term physical effects, but the underlying condition may cause long-term effects.

For a correct diagnosis, the doctor will need to execute a full physical exam, which will probably include a proper neurological examination as well. In order to rule out possible diseases, blood tests (CBC, sedimentation rate, electrolysis, vitamins, sugar sedimentation rate of thyroid hormones, heavy metal drugs, antibodies to certain microbes, and proteins) and other laboratory tests, such as a spinal tap, are also undertaken. The doctor may also ask for urine tests (glucose, proteins, etc.), as well as perform electromyography, nerve conduction tests, lumbar puncture (done only when central nervous system disorders such as meningitis or multiple sclerosis are suspected), vascular ultrasound, and a self-stimulation test (to check for Raynauds phenomenon). A nerve biopsy is rarely done. If the doctor suspects an issue with the spine or neck, certain imaging tests, such as MRI scans, CT scans of the head and/or spine, and X-rays of the chest, abdomen, bones, or joints may also be recommended.

According to the results of the tests, the doctor will then refer the patient to a specialist for the specific condition, such as an endocrinologist, orthopedist, or neurologist.

Misdiagnosis

Since paresthesia may not be severe, or one may not seek medical care, its diagnosis may be delayed or missed. There may also be a delay in diagnosing the underlying or associated disease. Noticeable symptoms such as paresthesia in diabetes may not occur for months or years. Paresthesia may occur as a symptom of other underlying medical conditions, hence, a thorough medical evaluation is necessary to ensure an accurate diagnosis.

The following conditions are considered possible alternative diagnoses for paresthesia:

• Diabetes mellitus
• Hypocalcemia
• Alcoholism
• Entrapment mellitus
• Multiple sclerosis
• Nerve root compression
• Herpes zoster
• Partial seizure
• Thoracic outlet syndrome
• Brachial plexus neuropathy
• Reflex sympathetic dystrophy
• Migraine
• Transient ischemic attack
• Spinal cord lesion

Paresthesia normally goes away on its own within a few minutes, in the case of temporary paresthesia. However, if a certain part of the body continually experiences the “pins and needles” feeling or repeatedly goes numb, consult a doctor. With temporary paresthesia, where people experience the tingling feeling due to limbs falling asleep, circulation can be restored through stretching, exercising, and massaging the affected limb. This will instantly remove the numbness and tingling.

In the case of chronic paresthesia due to circumstances such as chemotherapy treatments or diabetes, doctors will suggest treatments that bring relief by targeting specific symptoms. If the symptoms are mild, patients can intake anti-inflammatory medicines, such as aspirin or ibuprofen.

Doctors usually recommend antidepressant medications for people who experience more persistent paresthesia. However, they are usually at a much lower dosage compared to the amounts used to treat clinical depression. Such antidepressant medications can be of some assistance, because they have the ability to alter a person's perception of pain.

Opium derivatives like codeine are also prescribed by doctors for more severe cases of paresthesia. Doctors are also finding new ways to help nerves grow and assist in regenerating damaged nerves, thus doing away with the symptoms of chronic paresthesia.

A large number of alternative treatments have been researched and made available to the general public to help relieve the symptoms of chronic paresthesia. Among these homeopathic remedies is nutritional therapy, which includes the supplementation of a vitamin B complex, particularly vitamin B12. Nevertheless, supplementation of vitamins should be practiced with the utmost caution, as an overdose of some vitamins can worsen the condition and degenerate your entire well-being. For example, an overdose of vitamin B6 is proven to be one of the causes of paresthesia. It is also recommended that people who experience chronic paresthesia completely avoid the consumption of alcohol.

Self-massaging using aromatic oils can be helpful. Capsaicin is a topical ointment that makes peppers hot. Application of this might provide relief from this condition. Wearing loose-fitting clothes and shoes might also help. 

You cannot always prevent paresthesia; after all, you can’t be alert enough all night not to fall asleep on your arm. However, you can still take steps to lower the severity or occurrence of paresthesia.

For instance, to help treat the symptoms of paresthesia caused by pressure put on a nerve during sleep, you can use wrist splints at night to ease the compression of the nerves in your hand.

Among the natural methods proven to cure paresthesia and provide symptom relief are massages and acupuncture. These two methods are truly miraculous, as self-massage through the use of aromatic oils proves extremely helpful in curing the persistent “pins and needles” feeling. Doctors also suggest applying ointments containing capsaicin, which is the substance that makes peppers hot. Wearing loose-fitting shoes and clothes is also helpful.

Other ways proven to prevent chronic paresthesia include:

• Staying away from any sort of repetitive movement when possible
• Getting proper rest in case one needs to undergo repetitive movements that could cause nerve damage
• Staying energetic and moving/walking around as often as possible, especially when the routine includes sitting continuously for long periods
• Carefully managing and monitoring chronic diseases like diabetes

Normally, temporary paresthesia is resolved within a few minutes without any major hassle. However, if the sensations do not go away or keep coming back, this is a sign of chronic paresthesia, which can severely complicate daily life. Hence, you should visit your doctor to find the underlying cause of the condition. Also, it is advised to seek a second opinion from a specialist, if deemed necessary.

How long your paresthesia will last depends on the cause. To cope with both types of paresthesia, you should have an energetic lifestyle that includes healthy eating and regular physical exercise. This will not only keep the symptoms away, but will also keep your health in check and prevent other diseases known to cause paresthesia.

In order to fully benefit from chronic paresthesia treatment, you need to take your medications regularly and convey your progress to your doctor.

There are no severe risks or complications associated with paresthesia unless the symptoms and causes are hiding an underlying condition. In most cases, paresthesia is caused by damaged nerves as a result of injury, accident, or a neurological disorder. The risks attached to these are much more severe and should be handled with care and proper treatment. Still, a majority of paresthesia cases are temporary and can be treated with just a little stretching and exercising, but if this doesn’t work, you need to make a medical visit soon.

Prognosis

Prognosis depends on the underlying medical cause. There has been no known long-term physical effect from paresthesia alone. However, if there is an underlying condition that leads to paresthesia, it may cause permanent nerve damage. Hence, it is necessary to check with the doctor when the cause is uncertain.