Neuropathic Pain

What is Neuropathic Pain?

Neuropathic pain is a complex and often chronic pain condition caused by damage or dysfunction within the nervous system. The human nervous system is an intricate network that includes the central and peripheral systems which both play a crucial role in the sensation and perception of pain. The central nervous system includes the brain and spinal cord, and the peripheral nervous system encompasses the nerves extending to various body parts like the limbs, trunk, and face. Neuropathic pain arises when there is an injury or disorder impacting either the peripheral or central nervous system. This disruption can lead to the misfiring of pain signals to the brain which results in sensations that are often severe and persistent.

Characteristically, neuropathic pain presents in diverse forms that can range in severity and occurrence. Neuropathic pain can be identified as episodic to continuous. Episodic neuropathic pain is frequently likened to electric shock sensations, whereas continuous neuropathic pain is described as enduring aching, burning, hypersensitivity, or coldness. In the context of neuropathic orofacial pain, the discomfort predominantly affects the mouth and face which can significantly impact a patient’s quality of life. Pain caused by different types of orofacial neuralgias can be challenging to manage and often requires a comprehensive approach for diagnosis and treatment. Understanding its complex nature is critical for effective management and relief which is why it is important to be seen and treated by qualified orofacial pain experts. The Headache TMJ Los Angeles Pain Clinic provides specialized care by expert TMJ and orofacial pain doctors who deliver effective cutting-edge treatments.

Different Types of Orofacial Neuralgias

Orofacial neuropathic pain disorders are characterized by pain resulting from nerve dysfunction or damage. Symptoms can manifest in specific or generalized areas of the face, head, mouth, or neck. These disorders encompass a range of symptoms that are broadly characterized by sensations of pain, aching, burning, numbness, or tingling that affects areas in the head and shoulders. The intensity and nature of the pain vary among different conditions and can range from a constant dull pain to episodic, shock-like burning sensations:

• Trigeminal Neuralgia: This condition is the most common form of orofacial neuropathic pain. It involves the trigeminal or 5th cranial nerve and it causes sudden, intense facial pain. The sudden, severe stabbing pain can affect any of the three branches of the trigeminal nerve that are responsible for facial sensations. The upper branch receives signals from the scalp, forehead, brain, and upper skull. The middle branch receives signals from the cheeks, top lip, upper jaw and TMJ, upper teeth and gums, and nose. The lower branch receives signals from the lower jaw and TMJ, lower teeth and gums, and bottom lip. Trigeminal neuralgia pain can impact multiple branches of the nerve at the same time and present as pain on both sides or one side of the face. Occurrence of pain can vary but episodic outbursts can last from a few seconds to two minutes. These pain episodes can occur frequently throughout the day and are often triggered by contact with the affected area like when an individual touches their cheek, teeth, or scalp. Patients may experience periods of pain followed by intervals of relief. However, as the condition progresses, these painful periods occur more frequently.
  • Episodic vs chronic: Episodic pain can occur in short bursts which can be triggered by contact with the injured area. Episodes can last between days to months before going dormant for months. However, conditions tend to worsen over time with episodes becoming for frequent. Chronic pain occurs when there is no relief from the pain.
  • Type 1 vs Type 2: Type 1 pain is characterized by a sudden, shocking pain that feels sharp and stabbing or burning. Type 2 pain is characterized by constant aching pain that can be described as burning or coldness, numbness, and “pins and needles.”
• Glossopharyngeal Neuralgia: This affects the glossopharyngeal nerve which results in pain in the throat, ear, and tongue.
• Occipital Neuralgia: In this condition, the occipital nerves are involved which lead to pain in the back of the head, neck, and behind the ears.
• Vagal Neuralgia: This neuralgia impacts the vagus nerve which causes pain sensations in the ear, throat, and voice box.
• Superior Laryngeal Neuralgia: This affects the superior laryngeal nerve which results in pain in the throat and upper neck area.

• Atypical Odontalgia: This condition is also known as phantom tooth pain. It is most commonly felt after dental procedures and is characterized as a toothache-like pain without an identifiable dental cause. Patients typically feel persistent aching pain in a tooth or multiple teeth.

• Oral Nerve Injury: This involves neuropathy of the inferior alveolar or lingual nerve and manifesting as pain, numbness, or tingling in the tongue, mouth, or lower lip.
• Complex Regional Pain Syndrome (CRPS): Though primarily affecting limbs, CRPS is a rare chronic condition that can also affect the craniofacial region. It is categorized into CRPS I (related to tissue injury) and CRPS II (related to nerve injury) and is characterized by continuous burning pain, sensitivity to touch, and changes in skin temperature, color, and texture. The syndrome progresses through three stages, each marked by intensifying symptoms and physical changes. In the final stage, changes to the skin and bone become irreversible, leading to significant muscle loss, limited mobility, and involuntary muscle contractions.

Each of these neuralgias has distinctive characteristics and requires specialized care for effective management which can be provided by the Headache TMJ Los Angeles Pain Clinic.

Neuropathic Pain Treatment

Neuropathic pain treatment can be complex because it needs to treat the underlying cause of nerve pain, provide pain relief, maintain function, and improve quality of life. To achieve these goals, it isn’t uncommon to require several treatment modalities to ensure that the benefits from each treatment option are unlocked.

Neuropathic Pain Medications

Doctors can prescribe different medications to try and alleviate neuropathic pain symptoms. It is important to speak to an experienced doctor to ensure that the medication that is prescribed is the best option for you. Determining an effective regiment of medications usually takes some trial and error and will be prescribed in small trial doses to get the medication levels correct. This is because several of the medication options have side effects that need to be weighed against the benefits. Medications generally do not treat the cause of pain, but instead mask symptoms or block pain signals.

• Anticonvulsant medications: Gabapentin, Pregabalin, Topiramate, Carbamazepine, Lamotrigine
  • Effects: Blocks the pain of trigeminal neuralgia which causes intense, short-term pain.
  • Side effects: Chest pain, constipation, confusion, drowsiness, nausea, heart problems, & allergic reactions
• Antidepressant medications: Amitriptyline, Nortriptyline, Venlafaxine, Duloxetine
  • Effects: Reduces pain by fixing imbalances in the nervous system’s neurotransmitters.
  • Side effects: Heart problems, constipation, drowsiness, light headedness, weight gain, dry mouth, nausea, & suicidal thoughts
• Opioid analgesics: Tramadol, Oxycodone, Oxycontin, Roxicodone
  • Effects: Provides significant pain reduction and relief.
  • Side effects: High chance of abuse, overdose, dependence, adverse long-term effects, drowsiness, constipation, vomiting, breathing problems, & nausea
• Topical treatments: Lidocaine, Capsaicin creams
  • Effects: Provides local relief by numbing pain where medication is applied.
  • Side effects: Swelling, burning, skin irritation, cough, tightness in chest, trouble breathing
• NSAIDs (Non-Steroidal Anti-Inflammatory Drugs): Aleve, Motrin
• Localized treatments: Steroid injections, local anesthetic

There is also the possibility that the nerve pain is being caused by some other ailment that may require its own set of medications to help reduce neuropathic pain symptoms.

Neuropathic Pain Therapies

When medication has failed to produce results, there are therapies that can also help alleviate nerve pain symptoms.

Physical Therapy: Muscle weakness can come as a result of nerve pain so exercising and regular movement will help strengthen surrounding muscles. This will improve mobility and could help improve nerve pain caused by pinched or compressed nerves.

Relaxation Therapy: On going stress leads to higher levels of cortisol being released in your system. This can result in muscle tension and a chronic state of inflammation which can exacerbate neuropathic pain symptoms. Finding time for self-care can help improve your body’s ability to handle stress and can potentially reduce nerve pain through activities like yoga and meditation which reduce stress and help with circulation.

Acupuncture: This therapy uses sterilized needles to activate pressure points around your body. This is said to reduce neuropathy symptoms and inflammation.

Neuropathic Pain Surgeries

Some of these therapies are slightly more invasive and require a minor procedure.

Plasma Exchange: This procedure is designed to suppress the immune system to help reduce inflammation. It involves removing blood and isolating certain proteins and antibodies before returning the blood back to your body.

Spinal Cord / Peripheral Nerve / Brain Stimulation: These treatments require an implant that delivers electrical stimulation to different parts of your nervous system to interrupt pain signals that are sent to the brain.

Additional surgeries can help address other ailments that are contributing to nerve pain. This could include the removal of tumors that are adding pressure to nerves.

Neuropathic Pain Lifestyle Changes

Sometimes the underlying cause of neuropathic pain is a disease like diabetes. When this is the case, adjusting your lifestyle to reduce diabetes symptoms will also help minimize the neuropathic pain symptoms as well. This can include:

• eat healthy
• cut back on sugars
• watch your weight
• exercise regularly
• quit smoking
• avoid alcohol and drugs
• maintain glucose levels
• take care of feet

Neuropathic Pain Relief

Sometimes the cause of neuropathic pain isn’t easy to identify so the cause can’t be treated. This makes treating neuropathic pain focus more on pain relief and methods of improving quality of life and daily function. Without being able to treat the underlying problems, a multimodal treatment plan will help reduce pain symptoms. It is important that early treatment is implemented to help prevent other problems that come with nerve pain. By treating nerve pain early, there is a chance that outcomes like depression, sleeplessness, and restricted function can be avoided.

Different Orofacial Neuralgia Treatments

There are various treatments available for orofacial neuralgia that are each tailored to the specific type and symptoms of the condition. A combination of therapies is typically effective in managing orofacial neuropathic pain symptoms and treatment plans should always be developed in consultation with an experienced orofacial pain expert.

• Trigeminal Neuralgia:
  • Anti-seizure Medications: These are commonly the first line of treatment. Drugs like carbamazepine, oxcarbazepine, clonazepam, and topiramate help decrease nerve overactivity. The dosage is carefully adjusted to balance efficacy and side effects.
  • Tricyclic Antidepressants: Useful especially when the pain is constant, burning, or aching.
  • Rhizotomy Procedures: These involve destroying specific nerve fibers to block pain, which may result in facial numbness. Techniques include balloon compression (damaging the nerve with an inflated balloon), radiofrequency lesioning (destroying nerve fibers with a heated electrode), and stereotactic radiosurgery (using focused radiation to create a lesion on the nerve).
  • Microvascular Decompression: A surgical approach that involves placing a cushion between the trigeminal nerve and the compressing blood vessel.
• Atypical Odontalgia:
  • Treatments include local anesthetics and steroid injections if pain is localized near teeth or gums. Topical medicinal creams, antiseizure medications, and tricyclic antidepressants may be used for broader pain relief.
• Oral Nerve Injury:
  • Surgical repair is an option if pain persists beyond 6 to 8 weeks post-injury. Success rates for nerve repair are higher when surgery is performed closer to the time of the initial injury, with many patients experiencing significant symptom improvement.
• Complex Regional Pain Syndrome (CRPS):
  • Treatment typically involves a combination of medications like antidepressants, pain medications, blood pressure medications, nerve block injections, and physical therapy. In severe cases, sympathectomy, which is a surgical, chemical, or radiofrequency disruption of the sympathetic nervous system, may be considered.

It’s important to note that treatment effectiveness varies among individuals, and ongoing management with an orofacial pain specialist like Dr. Omrani at the Headache TMJ Los Angeles Pain Clinic, is crucial for optimal outcomes. The goal is not only to alleviate pain but also to improve the overall quality of life for those suffering from orofacial neuralgias.

Different Types of Neuropathic Pain

Neuropathic pain can encompass several types of peripheral neuropathy. This can include:

• Mononeuropathy: Affects one primary nerve
• Mononeuritis Multiplex: Affects several nerves
• Polyneuropathy: Affects all the nerves in the nervous system

Polyneuropathy is the most common type that most people deal with. It affects people differently, but pain is generally felt in the longest nerves first. This means that most people will feel the impacts of polyneuropathy in their feet and legs first before it eventually starts to affect their arms and hands. This is commonly caused by diabetes which results in diabetic polyneuropathy.

It is also important to identify which nerves can be impacted by neuropathy. Nerve pain and dysfunction can impact:

• Sensory nerves: These are nerves that perceive sensation like temperature, pain, touch, and vibration.
• Motor nerves: These nerves control muscle movement
• Automatic nerves: These nerves control normal bodily functions like blood pressure, heart rate, digestion, and bladder use

Neuropathic Pain Causes

Discovering the cause of neuropathic pain can be difficult given the wide variety of ailments that can lead to nerve damage. Some of those diseases / disorders that can lead to or contribute to nerve pain are:

• Cancer / Tumors (Myeloma, Lymphoma, Amyloidosis)
• Stroke
• Diabetes
• Malnutrition (Vitamin B1, B6, B12, E deficiencies)
• Infection (Chicken Pox, Shingles, Syphilis, HIV, AIDS, Lyme Disease, Hepatitis B & C, Leprosy, Diphtheria)
• Autoimmune system disorders (Lupus, Rheumatoid Arthritis, Guillain Barre Syndrome, Sjogren’s syndrome)
• Hormone / Thyroid disorders
• Excessive alcoholism
• Chemotherapy & radiation therapy
• Amputation (Phantom Limb Syndrome)
• Nerve compression & inflammation (Carpal Tunnel Syndrome, herniated disc, trapped median nerve)
• Central nervous system disorders (Parkinson’s, Multiple Sclerosis)
• Nerve trauma / damage / injuries (vehicle accidents, traumatic injuries, falls, sports injuries)
• Surgery
• Genetics (Charcot Marie Tooth Disease)
• Organ disease / dysfunction (kidney disease, liver disease, connective tissue disorders)

This list is not all encompassing of the potential causes for nerve pain. There are also cases where the case of nerve pain is classified as idiopathic which means that there is no discernable cause. These cases usually result in pain relief to reduce nerve pain symptoms.

Causes of Orofacial Neuralgias

Orofacial neuralgias, a group of conditions characterized by neuropathic pain in the facial and oral regions, can be attributed to various causes. The following are some of the primary causes:

• Nerve Compression: Nerve compression is a prevalent cause of trigeminal neuralgia that occurs when a blood vessel presses against a nerve and erodes its protective myelin sheath. This erosion leads to the transmission of abnormal signals to the brain.
• Tumors: Tumors at the base of the brain can also press against nerves which can affect the trigeminal nerve. This pressure may lead to the deterioration of the myelin sheath which can result in neuropathic pain in the head, neck, and face areas.
• Multiple Sclerosis: Multiple Sclerosis is an auto immune disease that affects the central nervous system and leads to inflammation and permanent damage to the brain and spinal cord nerves. This damage results in neuropathic pain in the face, neck, head in addition to other parts of the body.
• Physical Injury: Injuries from accidents or infections in the oral cavity can cause nerve damage. Such damage may lead to the continuous transmission of pain signals to the brain and even cause persistent pain after the injury has healed.
• Dental or Surgical Procedures: Orofacial neuralgia may stem from nerve deafferentation, particularly after dental procedures like root canals or extractions. Additionally, oral nerve injury can occur from local anesthetic injections or improper implant placement. This leads to pain, tingling, or numbness in the tongue, mouth, and lower lip due to damage to the inferior alveolar or lingual nerves.

Neuropathic Pain Symptoms

Symptoms of neuropathic pain may present themselves in different ways. These symptoms often affect different nerves like sensory nerves, motor nerves, and automatic nerves:

• Spontaneous pain: This pain is classified as pain that is shooting, burning, stabbing, or shocking. It also results in tingling, numbness, or what is generally referred to as “pins and needles.”
• Evoked pain: This is pain that is caused by what is normally non-painful stimuli. This can be the result of change in temperature or pressure.
• Dysesthesia: This is classified as an unpleasant and irregular sensation.
• Hypoalgesia: This is classified as pain that is less than what would be expected from a normal pain inducing stimulus.
• Trouble sleeping: This reaction is usually the result of pain like symptoms that prevent sleep.
• Loss of balance / coordination: Nerve pain can result in numbness which can cause loss of balance and coordination as other muscles try and compensate for muscle inactivity.
• Muscle weakness / paralysis: Nerve dysfunction can impact motor nerves which control muscle movement.
• Digestive problems: Automatic nerve damage can result in difficulty digesting food and controlling bladder and bowel function.
• Difficulty regulating blood pressure: Automatic nerve damage can also make regulating blood pressure difficult.

When to See a Neuropathic Pain Doctor

Early diagnosis is important to treating nerve pain and dysfunction so that long term impacts can be mitigated. If nerve pain goes undiagnosed it can develop even further which can cause more significant impacts down the line. Be sure to see an experienced neuropathic pain doctor as soon as you experience any early symptoms of peripheral neuropathy. This is even more important if a patient is dealing with other ailments that prove to exacerbate neuropathy or nerve pain, like diabetes, injury, or stroke.

Preparing to See Your Doctor

Once nerve pain has been identified as the problem, you will most likely be sent to a specialist who is trained to deal with nervous system disorders. In preparation of your doctor visit, it is helpful to be able to provide the following information:

• List of symptoms: Include all potential symptoms and when they started
• Personal information: Include all relevant personal information pertaining to family history, recent changes, injuries, diseases, and alcohol usage
• Current medications: Include any prescribed and OTC medications including supplements and vitamins

In addition to the above, be prepared to answer a series of qualifying questions that may include:

• Do you have any preexisting medical conditions such as diabetes or kidney / liver dysfunction?
• When did you first notice symptoms?
• Is pain or discomfort sporadic or constant?
• What type of pain is it and how intense is it?
• Does anything help reduce the pain?
• Does anything irritate or aggravate the pain?
• Is there a family history of neuropathy?

Questions to Ask Your Doctor

• What is prompting the neuropathic pain?
• Is there more that one problem that is contributing to the nerve pain?
• What tests will help diagnose the problem?
• What is the long-term outlook with neuropathic pain?
• Which treatments are available and recommended?
• What side effects should be expected during and after treatment?
• How do I manage any other health conditions with nerve pain treatment?
• What actions / activities need to be reduced or stopped?
• Where can I find additional information about neuropathic pain?

Neuropathic Pain Diagnosis

An experienced neuropathic pain doctor will need to conduct a neurological exam and review a patient’s medical history to gain further insight into potential neuropathic pain. This will help identify pain symptoms and inspect for injury in the search for the underlying cause of neuropathy. Physical examinations will normally test for sensation, strength, and reflexes. In addition to the physical exam, there are more tests that can be used to diagnose peripheral neuropathy. Blood tests can check for vitamin deficiencies, diabetes, and Charcot-Marie-Tooth disease. Specialized testing can also include:

• Nerve conduction test: This involves using electrodes to release electrical shocks to stimulate nerves.
• Electromyography: This involves injecting a small needle into muscle to evaluate electric activity.
• Lumbar puncture: This requires taking a sample of spinal fluid to check for inflammation.
• Nerve biopsy: This requires a sample of some peripheral nerve which is checked for abnormality under a microscope.
• X-Ray / CT scan / MRI scan: Imaging test can reveal herniated disks, pinched nerves, tumors, and several other abnormalities that could be applying pressure to nerves.

Diagnosing Orofacial Neuropathic Pain

Diagnosing orofacial neuropathic pain involves a multifaceted approach due to the diversity of its potential causes and manifestations. The diagnostic process generally begins with a comprehensive medical history review and a detailed description of symptoms, followed by a physical examination. Depending on the specific symptoms and suspected condition, various tests and scans may be employed to reach a conclusive diagnosis.

• Trigeminal Neuralgia: A physical examination of the affected area in addition to assessing symptoms and health history is crucial when diagnosing this condition. To rule out serious medical problems like tumors or multiple sclerosis, a Magnetic Resonance Imaging (MRI) scan is often recommended. In some cases, Magnetic Resonance Angiography (MRA) might be used to detect nerve compression by a blood vessel which is a common cause in trigeminal neuralgia cases. Interestingly, a positive response to Tegretol (an anticonvulsant medication) can also indicate trigeminal neuralgia. It is important to note that no single test definitively identifies all cases which makes the accurate interpretation of symptoms vital for diagnosis.
• Atypical Odontalgia: Diagnosing this condition is challenging, as it largely involves ruling out other potential causes. Along with assessing the characteristic symptoms of atypical odontalgia, doctors may suggest dental X-rays, MRI, or CT scans to exclude other conditions. Because it is difficult to diagnose, symptoms are normally attributed to atypical odontalgia after nerve blocks fail to alleviate pain and when no other positive diagnoses are made from test results.
• Oral Nerve Injury: This type of nerve damage is typically diagnosed using tests such as electromyograms (EMGs), which record electrical activity in muscles. When electrical activity is low, it could indicate nerve injury. Additionally, MRI or MRA scans can provide detailed 3D images to pinpoint nerve damage.
• Complex Regional Pain Syndrome (CRPS): CRPS requires a series of tests to help identify the disorder and eliminate other potential causes.
  • MRI Scans: Provides imagery that shows changes to tissue.
  • Sympathetic Nervous System Tests: tests that measure skin temperature, blood flow, sweat, and fluctuations in other autonomic body functions.
  • Triple Phase Bone Scan: Identifies changes in bone and blood circulations
  • X-Ray: Can show areas that have a mineral deficiency in late stages of the condition.

Neuropathic Pain Outlook

Neuropathic pain is complex so it can be difficult to treat. That being said, the multi modal treatment strategies have become increasingly effective at significantly reducing neuropathic pain symptoms. In addition to treatment, preventative and on-going rehabilitation will be critical to maximizing quality of life. Neuropathic pain is not typically life threatening but can have an overall negative impact by causing depression, sleeping problems, anxiety, and more. Finding the correct treatment strategy is critical to ensuring that pain symptoms are minimized while still being able to live a fulfilling life.