Abnormal sensations are known as paresthesias. It can include a host of sensations such as prickling, tingling or even burning. These sensations would not be considered abnormal if there are some stimuli, like an irritant on the skin surface or even mild tissue damage before pain occurs.
However, when it occurs despite there being any stimulus then it may indicate a nerve problem. At the other end of the paresthesia spectrum is numbness where there is a loss of sensation. Paresthesias can occur anywhere on the body. The limbs (arms and legs) and head are some of the commonly affected sites for tingling or numbness.
Certain bands or segments of skin on the head are supplied by specific nerve. These nerve segments are known as dermatomes. It is therefore important to know which nerves supply specific dermatomes when investigating tingingling and numbness of the face and head.
Sensation on the face and top of the head is mediated by the right and left trigeminal nerve (fifth cranial nerve also denoted as CN V), which originates from the brainstem. The trigeminal nerve on either side divides into three branches each – the opthalmic nerve, maxillary nerve and mandibular nerve.
- The ophthalmic nerve travels through the ceiling of the orbit and enters the face above the eye. It innervates the front half of the top of the head, forehead, eyebrow, upper lid, the skin on the top of the nose, cornea, eye conjunctiva, and frontal sinuses.
- The maxillary nerve travels across the bottom of the orbit and enters the face below the eye. It innervates the skin on cheeks, upper lip, sides of the nose, lower eyelid, a part of mucosa in the nose, paranasal sinuses, upper gum, and upper teeth.
- Mandibular nerve:
a) The mental branch travels along the inner side of the jawbone, enters the skin on the sides of the chin and innervates the skin of the jaw.
b) The auriculotemporal branch innervates the skin in the front of the ear (pinna), and temporal region.
Picture 1. Sensitivity map of the head – head dermatomes
Sensation at the back of the head is mediated by the first three spinal nerves (cervical nerves C1 to C3) .
Sensation of the neck and most of the outer ear is provided by the superficial cervical plexus composed of cervical nerves (C1 to C4).
Causes of Numbness on the Head
Head and face numbness or tingling is caused by problems of the cervical (C1-C4) nerves and trigeminal nerve. Any condition affecting certain segments of the spinal cord, the brainstem or the brain can also result in tingling and numbness since these structures are responsible for transmitting signals from the face and head or deciphering the signals from these areas.
- Spinal disorders like a herniated disc.
- Neurological diseases like multiple sclerosis.
- Vascular disorders like atherosclerosis.
- Infections like meningitis.
- Poisoning, particularly with heavy metals like lead poisoning.
- Traumatic head injuries.
- Metabolic changes like hypokalemia.
There are also other causes, some of which are discussed in greater detail below.
Nerve and Brain
Most of the causes of head and face tingling or numbness are neurological (nerve or brain) conditions
Herpes Zoster (Shingles)
Herpes zoster (shingles) is a reactivation of the chickenpox virus in the nerve roots. It may have remained dormant here for decades. It can then inflame the trigeminal or cervical nerves at any time after the chickenpox infection. It may cause:
- Tingling on the one side of the face, scalp or trunk, followed by a band of red patches and painful blisters. Sometimes there is no rash but only tingling sensation.
- Pain may occur over the affected area.
- Fever, headache, impaired vision, hearing or taste.
Post-herpetic neuralgia is a complication of herpes zoster reactivation (shingles). It is mostly seen in people over 60 years of age. Facial tingling, numbness or pain may last for several months or even for years. There is also sensitivity to touch and itching may also be present. There is no cure but it usually resolves over time.
Lyme disease is a tick-borne infection caused by the bacterium Borrelia burgdorferi. Symptoms include:
- Circular red rash with a pale centre appearing a few days or weeks after a tick bite. The rash may last for a few weeks.
- Fever and fatigue are sometimes present.
- Tingling, paralysis of the facial muscles, visual disturbances, poor memory, migratory joint pains (especially in the knees) and heart problems can appear months to years later.
Trigeminal neuralgia (tic douloureux) is a chronic nerve disorder of unknown origin, mostly affecting adults. It causes:
- Sudden severe shock-like (or mild) facial pain, lasting from few seconds to two minutes. The pain is triggered by tooth brushing, shaving, chewing, speaking, laughing, or even a slight breeze.
- Tingling and numbness as a warning symptom before the pain attack.
Symptoms may be episodic but often progresses in frequency and severity.
Trigeminal Neuropathic Pain
Trigeminal neuropathic pain can appear as a complication of trauma, dental procedures, surgery or diseases like diabetes or stroke. Symptoms ae usually on one side of the face and includes:
- Constant dull or burning pain.
- Numbness and tingling.
Pain in trigeminal deafferentation (interruption of sensory nerve fibers) is a consequence of nerve damage, usually during the treatment of trigeminal neuralgia (injections or surgery). The main symptoms are continuous burning or numbness in the affected area.
Anesthesia dolorosa is usually a complication of treating trigeminal neuralgia. Symptoms may include facial numbness or a constant stabbing pain.
Multiple sclerosis (MS) is an autoimmune disease affecting the brain, brainstem or spinal cord. Symptoms usually appear between 20 to 40 years of age and include:
- Blurred vision or even blindness, usually in one eye at the time.
- Muscle weakness or paralysis, usually on one side of the body.
- Unusual sensations or pain anywhere in the body/
- Impaired speech, hearing loss and balance.
- Difficulty with concentration.
In epilepsy, abnormal electrical activity in the brain cells can cause seizures. There may be tingling, numbness, change in taste or smell followed by convulsions, muscle spasms, and sometimes loss of consciousness.
In a rare Guillain-Barré syndrome, immune system, usually some days or weeks after respiratory or food poisoning, attacks peripheral nerves. Symptoms can develop fully in few hours or few weeks, rarely extend over 2 months and may include:
- Muscular weakness and numbness starting in the feet and progressing to the upper trunk and head. Sometimes the symptoms start in the hands or face and proceed toward the legs. Refer to weak legs.
- Difficulty with bladder and bowel control.
- Severe back pain.
- Slow heart rate.
- Difficulty with eye and facial movements, speaking, chewing or swallowing.
- Difficulty breathing (only in severe cases).
Syphilitic myelopathy (tabes dorsalis) is a rare complication of untreated syphilis. Symptoms:
- Abnormal sensations (“lightning pains”).
- Muscle weakness and loss of reflexes.
- Loss of coordination, difficulty with walking and a wide gait.
- Psychiatric illness.
Anxiety and Panic Attack
Paresthesias are not uncommon during episodes of anxiety and even panic attacks. However, paresthesias should be immediately attributed to anxiety or panic attacks unless other causes have been excluded, particularly in seniors where there is a high risk of conditions like a stroke. Apart fom the tingling or numbness, there may also be feelings of intense fear and apprehension coupled a rapid heat rate, hyperventilation, sweating and trembling.
Various foods and beverages may cause symptoms like tingling or numbness of the face and head for different reasons. It may be related to a food allergy where the immune system triggers an abnormal response to othewise harmless substances. The other possible cause may be poisoning due to the presence of toxic substances in foods, as is the case with ciguatera poisoning, scombroid poisoning and paralytic shellfish poisoning.
Stroke and TIA
Stroke is death of a part of the brain tissue occurring after a blockage in or break of a brain artery. Transient ischemic attack (TIA) or “mini stroke” occurs when a blood supply is only briefly interrupted with no brain tissue death. Symptoms appear suddenly and may disappear within minutes to hours in a TIA but will be prolonged or even permanent in a stroke.
- Numbness or weakness of the face, arm, or leg, usually on one side of the body
- Trouble speaking, difficulty swallowing and visual disturbances.
- Confusion and impaired memory.
- Permanent paralysis.
Symptoms in the stroke may be permanent but some can often improve within weeks/months with proper rehabilitation.
Vertebrobasilar Circulatory Disorders
In vertebrobasilar circulatory disorders, the blood supply to the back of the brain (cerebellum) and brainstem are disrupted due to blocked basilar or vertebral arteries. Characteristic symptoms include:
- Complete or partial vision loss.
- Double vision
- Poor balance and impaired coordination.
- Numbness and tingling of the head.
There may be other symptoms that are simlar to a stroke.
Angina pectoris (Latin angina = tightness, pectus= chest) is a symptom of insufficient oxygen supply to the heart. It is mostly due to narrowed coronary arteries that supply the heart with oxygenated blood. It rarely appears before 30 years of age. Symptoms are similar to a heart attack and includes:
- Sharp or dull pain behind the breastbone, triggered by physical activity, intense emotions, or other stress. The pain may last for a few minutes (up to 30 minutes in severe cases).
- Pain or numbness my radiate to the jaw, left shoulder, arm or hand.
- Dizziness, sweating, nausea and shortness of breath.
Head tingling and numbness can result from an impaired blood supply to the nerves caused by nflammation of small to medium sized arteries. This is a condition known as vasculitis. There are several different types of vasculitis, including temporal arteritis (giant cell arteritis), Wegener’s granulomatosis, necrotizing vasculitis, polyarteritis nodosa, posterior inferior cerebellar artery syndrome and thoracic outlet syndrome, among others.
Head or Spinal Cord Injury
Cuts, punctures, bruises, skull fractures/facial bone and vertebral fractures can affect peripheral nerves or cause spinal cord injury and brain injury which may lead to numbness or tingling. Dislocated jaw may cause pain or numbness in temporal and jaw area – temporomandibular joint (TMJ) pain. Spinal cord injuries of the upper cervical (neck) spine, above the C4 level, may result in tingling and numbness of the head. These injuries can occur with a blow to the head or neck during contact sports, falls, assault or vehicle collisions.
The following disorders affecting the cervical spine (above C4 level) can cause tingling, numbness or pain at the back of the head.
- Spinal arthritis (spondylitis)
- Spinal stenosis
- Degenerative disc disease (DDD)
- Bulging or herniated disc (slipped disc)
A tumor (benign or malignant) or abscess (collection of pus after infection) in the brain, orbit, ear, nose, paranasal sinuses, mouth, parotic glands, muscles, skin, skull, vertebra or spinal cord can directly press on the nerve tissue or infiltrate it in the case of cancers. This can cause unusual sensations or pain in the face or back of the head, along with other symptoms like tingling, numbness, weakness and/or paralysis.
Substances, like neurotransmitters, secreted by various tumors (especially lung cancer and carcinoid) can cause paresthesia in any part of the body.
Metabolic disorders that may result in tingling anywhere in the body:
- Abnormal blood levels of calcium (hypocalcemia, hypercalcemia), potassium (hypokalemia, hyperkalemia), magnesium, sodium, vitamin B1 (thiamine), B6, B12, thyroxin and aldosterone.
- Hypoglycemia (low blood sugar) that more commonly occurs in insulin dependent diabetics, chronic alcoholics, with prolonged starvation, excessive exercise and in dumping syndrome.
- Uremia (in chronic kidney failure).
- Porphyria – inherited or acquired disorder of heme (part of hemoglobin) synthesis.
- Hypothyroidism, hypoparathyroidism and hypoaldosteronism (Conn syndrome).
Drugs and Toxins
- Medication such as anti-convulsant drugs, lomotil, amiodarone, colistimethate, digoxin, dimercaprol, mefloquine, riluzole, tetrodotoxin, thallium, topiramate, antiretrovirals, metronidazole and an overdose of lidocaine or SSRI (antidepressants) withdrawal.
- Excessive vitamin B6 supplementation.
- Radiation therapy and chemotherapy.
- Alcohol causes alcohol neuropathy (chronic paresthesia),but it can be directly toxic to nerves (acute paresthesia). Alcohol withdrawal after long term drinking can cause tingling or prickling sensations.
- Tobacco (usually excessive use).
- Poisoning: heavy metals (arsenic, lead, mercury), nitrous oxide, ciguatera poisoning with tropical fish, snake bites and carbon monoxide.
- Infections: HIV, leprosy, herpes simplex, rabies, canker sores and arbovirus infections.
- Connective tissue and autoimmune diseases: rheumatoid arthritis, systemic lupus erythematosus (SLE), Sjögren’s syndrome.
- Blood disorders: thrombosis, polycythemia, thrombocytosis, leukemia and pernicious anemia.
- Bones and joints disorders: arthritis and osteomalacia.
- Nutrient deficiency: vitamin B1 (beriberi), vitaming B5 and vitamin B12 deficiency.
- Hereditary diseases: Refsum disease, Fabry disease, Charcot-Marie-Tooth disease, porphyria , Denny-Brown’s syndrome and ataxia-teleangiectasia.
- Immune deficiency as may be seen with malnutrition, HIV infection and uncontrolled diabetes.