Top 10 chronic pains - tips and tricks for general practitioners

As pain specialist physicians, we see it all and treat it all! That’s what we’ve been trained to do.

Early diagnosis, means early treatment. Early treatment means early pain control. Early pain control means early reduction in suffering.

Here are a few tips and tricks in managing 10 of the commonest pain conditions we treat:

1. Chronic post surgical pain

Everyone experiences some type of pain following a surgical operation. It is usually well managed with medications and settles as healing occurs. But not always!

Chronic post surgical pain should be considered when pain persists for > 2 months following surgery, or when pain persists after normal tissue healing is expected to have occurred. The consequences of chronic post surgical pain are significant and include:

• Increased analgesic use
• Reduced activities of daily living or level of function
• Reduced quality of life
• Increased suffering

Other causes of pain such as a new disease process, infection or cancer reoccurrence must be excluded before a diagnosis of chronic post surgical pain can be made.

Common surgeries that can lead to chronic post surgical pain include:

• Amputation
• Thoracotomy
• Mastectomy
• Inguinal hernia repair
• Coronary bypass
• Caesarean section

But remember almost any surgical procedure can cause chronic pain, even the minor ones like dental surgery so have a high index of suspicion.

Patients may be discharged from hospital on significant opioid therapy and then they attend you, their general practitioner, looking for ongoing opioid therapy. This is OK for a short time.

But if pain persists for more than 2 months after surgery or persists after expected tissue healing, consider whether you are dealing with chronic post surgical pain.

Neuropathic pain is likely to be a key component in the pathophysiology of chronic post surgical pain. Neuropathic pain is pain arising as a direct consequence of a lesion or disease affecting the somatosensory system, and generally, in the case of surgery, that means a surgical injury to the nervous system, usually in the form of peripheral nerve damage, which sets up peripheral sensitization, which in turn can set up central sensitization. Both peripheral and central sensitization can be difficult to manage.

So if someone presents to you with persistent post-operative pain that is poorly controlled with opioids, use multimodal therapy e.g. trial NSAIDS and tramadol, if possible.

Then have a low threshold for adding in combination antineuropathic agents early e.g. pregabalin and duloxetine. These will reduce sensitization and will allow you to wean the opioid therapy earlier. And it will reduce pain and reduce suffering.

Monitor these patients closely. If the pain persists or you find it difficult to manage, get them to a pain specialist, who have much more up their sleeves, which might include ketamine infusions, nerve blocks, neurostimulation combined with an allied health team approach.

2. Lower back pain

As you know, back pain is common and debilitating. A few pointers in managing back pain:

• Exclude red flags like fractures, tumours, infections by searching for seeking a history of trauma or spontaneous osteoporotic fractures, weight loss, signs of infection or sepsis. If there are any signs of neurology, this also needs further investigation.
• Advise a short period of rest only. Then mobilse early.
• If there are muscle spasms, use benzodiazepines for a few days only.
• Consider the more common causes of chronic lower back pain:

Discogenic pain. 

Discogenic pain is a dull central back pain that is not usually releved by lying down.  This pain can be hard to treat but there are some newer trend which include intradiscal therapies like pulsed radiofrequency and even PRP injections. 

Facetogenic pain. 

Facetogenic pain is worsened on hyperextension or loading the facet joints, is usually one side or bilateral, is paraspinal pain, with pain on direct palpation of the facet joints. Facet joint blocks only provide short-term pain reduction. Not only are they sort lived but might risk damaging the joint capsule as the joint are so small. Rather get your pain specialists to do medial branch blocks on the facet joints and if positive, perform radiofrequency neurotomy. These can give pain reduction from 4 months to 2 years particularly when combined with appropriate pain physical therapy. 

Sacroiliac joint pain 

Sacroiliac pain is similar to facet joint pain but occurs in the buttock and can radiate down into the leg, because the sciatic nerve is anterior to the sciatic joint, which can become irritated. Diagnostic sacroiliac joint blocks can be done and even followed by radiofrequency neurotomy, as per the scientific approach to facet joint pain.

More reading on lower back pain is here

3. Chronic headaches

A headache is considered chronic if it occurs for three months in a row and for at least 15 days out of each month.

There are many causes of headaches it’s important to confirm there are no red flag causes like high blood pressure, multiple sclerosis and space occupying lesions. i.e. always exclude secondary causes of headaches.

Exclude sources of referred pain, which may include: areas of the head that you may overlook, like the TMJ, teeth, eyes, sinuses, ears and the neck (see cervicogenic headaches below).

Neuralgic headaches

Also look for neuralgic pains that may affect the multiple nerves around the head. These might include:

• greater occipital or lesser occipital neuraligia
• auriculotemporal neuralgia
• supraorbital neuralgia
• infraorbital neuralgia
• supratrochlear neuraligia

Figure 2. Nerves of the head and face that may cause neuropathic pain. If these nerves are tender on palpation they may be the source of localised head and facial pains.

Cervicogenic headaches

Remember headaches can be caused by the neck, so called cervicogenic headaches.Diagnostic criteria for cervicigenic headaches:

- Unilateral (sometimes bilateral pain) precipitated by:

 - Neck movement and/or holding an awkward neck position

 - External pressure over the upper cervical or occipital region

- Restricted neck range of movement

- Diagnosis must be confirmed by diagnostic anaesthetic blocks (medial branch or greater occipital nerve)

- The nature of the pain is usually – one sided, and a vague, non-throbbing pain that can be moderate to severe. Sometimes it can even be associated with migraine type features like nausea, photophobia, phonophobia, dizziness and mile perioclar swelling. 

 

Chronic daily headaches

This is a huge healthcare problem and can be the most difficult group of patients to treat in a medical practice.

Consideration of chronic daily headaches if:

- Headache on at least 15 days/month.

- For at least 3 months.

Chronic daily headaches can either be primary or secondary and can either be short-duration or long duration chronic daily headaches. 

- Short duration chronic daily headaches: if the headache occurs for <4 hours e.g. chronic cluster headaches or paroxysmal hemicrania or short-lasting unilateral neuralgiform headache with conjunctival injection and tearing SUNCT. 

- Long-duration chronic daily headaches. If the headaches occurs for >4 hours this could include:
- Chronic migraine is defined as 3 month history of headaches occurring > 15 days/month and meet migraine criteria on > 8 days/month in the absence of medication overuse
- Chronic tension-type headaches
- Hemicrania continua
- New daily persistent headaches – a primary headache disorder and can resemble CTTH. Over 80% of patients can pinpoint the exact date of the onset of their headache
- Medication overuse headache

Chronic tension type headaches

Chronic tension-type headaches are caused by stress, fatigue or poor posture where the muscles of the neck, shoulders and scalp contract and may even generate small trigger points and tender areas. This can cause pressure on the head, leading to various types of headaches.

 

Chronic migraines

Migraines are common and debilitating. We know the symptoms all too well. 

 

Cluster headaches

Cluster headaches are characterized by frequently recurring, short lasting but extremely severe headache. It has episodic and chronic forms. 
- Episodic CH occurs in bouts (clusters), typically of 6-12 weeks’ duration once a year or two years and at the same time of year. Strictly one-sided intense pain develops around the eye once or more daily, mostly at night, until the pain diminishes after 30-60 minutes. 
- The eye is red and waters, the nose runs or is blocked on the affected side and the eyelid may droop. In the less common chronic CH there are no remissions between clusters. 
- The episodic form can become chronic, and vice versa, but once CH has struck it may recur over 30 years or more.

Criteria for general diagnosis of cluster headache
a. Headache descriptions (all 4) 
— Severe headache
— Unilateral
— Duration of 15 – 180min
— Orbital, periorbital or temporal location
b. Autonomic symptoms (unilateral) (any 2)
— Rhinorrhoea
— Lacrimation
— Facial sweating
— Miosis
— Eyelid oedema
— Conjunctival injection
— Ptosis
c. No evidence of secondary headache disorder. 

Episodic cluster headache occur for <1year and chronic headaches occur for > 1 year.

A first step common sense approach to migraines and cluster headaches might include:

• Make the diagnosis.
• Exclude secondary causes i.e. red flags
• Educate the patient.
• Lifestyle changes e.g. stopping caffeine, increasing exercise, stress management and improving sleep hygiene.
• Recognise triggers and avoid them.
• Determine type and frequency of attacks.
• Detect and treat co-morbidity e.g. depression, anxiety commonly co-exists.
• Use headache calendars and diaries.
• Individualise treatment.
• Use combination therapy where possible and get the patients off all forms of opioid therapy.

Get them to a pain specialist and/or neurologist early.

4. Complex regional pain syndrome

Complex regional pain syndrome like other chronic neuropathic pain disorders involves a combination of negative symptoms (sensory loss) and positive symptoms (intense burning pain, hyperalgesia and allodynia).

 Budapest diagnostic criteria for complex regional pain syndrome
1. Continuing pain, which is disproportionate to any inciting event
2. Must report at least one symptom in three (clinical diagnostic criteria) or four (research diagnostic criteria) of the following categories:
— Sensory: hyperesthesia or allodynia
— Vasomotor: temperature asymmetry, skin colour changes, or skin colour asymmetry
— Sudomotor or oedema: oedema, sweating changes, or sweating asymmetry
— Motor or trophic: decreased range of motion, motor dysfunction (weakness, tremor, or dystonia), or trophic changes (hair, nails, or skin)
3. Must display at least one sign at time of diagnosis in two or more of the following categories:
— Sensory: hyperalgesia (to pinprick) or allodynia (to light touch, deep somaticpressure, or joint movement)
— Vasomotor: temperature asymmetry, skin colour changes or asymmetry
— Sudomotor or oedema: oedema, sweating changes, or sweating asymmetry
— Motor or trophic: decreased range of motion, or motor dysfunction (weakness, tremor, or dystonia), or trophic changes (hair, nails, or skin)
4. No other diagnosis better explains the signs and symptoms

In severe cases of CRPS the changes can be so significant that the limb is distorted and displays severe contractures with the patients even neglecting the limb (sometimes referred to as hemisensory impairment).

The key with CRPS is to make an early diagnosis and get the patients to a pain specialist so they can use aggressive measures to reduce the pain, which will allow early mobilisation. The absolute key with CRPS is to get the body moving again. Spinal cord stimulation is now recommended early in CRPS.

5. Neuropathic pain

This can take the form of many different medical conditions. They key is to treat the cause, if you can find it e.g. diabetes, and treat the pain simultaneously. Here are some classifications of neuropathic pain.

Classification of neuropathic pain by aetiology:
- Trauma - phantom limb pain, spinal cord injury, surgery
- Ischaemia - painful diabetic neuropathy, central pain, surgery
- Infection/inflammation - post-herpetic neuralgia, HIV, surgery
- Cancer - invasion & compression of neural structures
- Drugs - vinca alkaloids, vincristines, taxanes, monoclonal antibodies
- Compression - trigeminal neuralgia
- Unknown - multiple sclerosis

Classification of neuropathic pain by site:
- Peripheral nervous system
     - Mononeuropathies (carpal tunnel, diabetes, post-herpetic neuralgia, ishaemic, cancer)
     - Polyneuropathies (diabetes, alcohol, HIV)

- Central nervous system - multiple sclerosis, spinal cord injury, post-stroke pain
- Mixed central and peripheral e.g. cancer

6. Post herpetic neuralgia

One of the commonest and most intractable pain conditions.

Varicella zoster virus causes chicken pox and herpes zoster (shingles). There is no consensus as to the definition but it is generally considered when pain persists after the rash of Zoster heals. Pain generally lasts more than 1 month.

Early diagnosis and aggressive treatment of zoster is vital in reducing the incidence of post herpetic neuralgia. Those at risk of post herpetic neuralgia are the elderly, the immunocompromised, those under psychological distress or living alone 

Aggressive and early treatment of zoster (shingles) reduces the risk of post herpetic neuralgia. Antivirals reduce the symptom pain of zoster and might include, acyclovir, famacyclovir or valaciclovir. Amitriptyline, reduces the incidence of post herpetic neuralgia so use it if your patients can tolerate it. Trial gabapentin too to reduces the intensity. Also consider topical lidocaine or topical aspirin. Vitamin C may be helpful

Repetitive paravertebral anesthetic block in combination with steroids plus standard treatment with acyclovir and analgesics significantly reduced the incidence of post herpetic neuralgia than the standard treatment alone.

All the following are efficacious for post herpetic neuralgia but cause side effects and no real long term studies i.e. studies usually less than 12 weeks follow-up: amitriptyline, desipramine, gabapentin or valproate or topical lidocaine or topical capsaicin.

Amitriptyline, capsaicin, divalproex sodium, gabapentin, morphine, nortriptyline, pregabalin, tramadol – all reduce pain intensity in post herpetic neuralgia. But the evidence does not guide us on which of these agents are best.

Sympathetic blocks e.g. stellate reduce the pain of zoster. Neurostimulation has been successfully used for refractory cases.

7. Trigeminal neuralgia

Trigeminal neuralgia is defined as a sudden, usually unilateral, severe brief stabbing recurrent pains in the distribution of one or more branches of the 5th cranial nerve. But there may be various types of trigeminal neuralgia including the typical form we all know. Other forms are atypical trigeminal neuralgia and trigeminal neuropathy.

 So if it doesn’t sound like they ‘typical’ form, it may be one of the other forms of trigeminal neuralgia

• Start with antineuropathic therapies like carbamazepine, oxcarbamazepine, lamotrigine, gabapentin. Other therapies might include baclofen and clonazepam.

• Always exclude MS in a young person or a lesion in the cerebellopontine angle.

• Refer to a neurosurgeon for consideration of microvascular decompression.

• Ablative therapies like balloon decompression of the gasserion ganglion, stereotactic radiotherapy, glycerol rhyzolysis may carry risks.

• A pain specialist that may consider: pulsed radiofrequency to the various branches of the trigeminal nerve or the trigeminal ganglion itself. This is a far less destructive therapy and may provide symptomatic control

8. Pelvic and visceral pain

Giamberardino summed it up beautifully by stating that there has recently been an important paradigm shift away from past views that viscera were insensitive to pain towards renewed interest by researchers and clinicians in pain that originates from internal organs. It has been considered that the social burden of visceral pain (pain originating from internal organs) may surpass that of pain from superficial (somatic) sources1, and these painful visceral conditions may include:

• Myocardial pain
• Kidney and uretheral stones
• Irritable bowel syndrome (IBS)
• Dysmenorrhoea

When visceral pain is specific and life-threatening e.g. myocardial infarction and peritonitis, the evaluation and diagnosis is relatively easy but when the pain is vague, changes over time and is associated with concurrent painful problems and psychological issues like anxiety and depression the evaluation and diagnosis can be difficult.

The International Association for the Study of Pain (IASP) definition of hyperalgesia is an increased pain sensitivity to a nociceptive stimulus. Functional bowel disorders like irritable bowel disease (IBS) and other visceral disorders display multiple characteristics that suggest the existence of visceral hyperalgesia.

The discomfort, pain, and altered sensations e.g. to intraluminal contents, that define this visceral hyperalgesia typically arise in the absence of tissue insult or inflammation and therefore visceral hyperalgesia could thus differ from somatic hyperalgesia, which is commonly associated with tissue injury and inflammation.

 The bottom line: body viscera can develop neuropathic pain and sometimes need to be treated as such, using the full gamut available to pain specialists.

9. Cancer pain

In cancer patients, pain is one of the most feared symptoms. However, despite the clear WHO recommendations, cancer pain still is a major problem (and sometimes still one of the most common symptoms)

A recent systematic review finding the following pain prevalences:

• 33% after curative treatment,
• 59% during anticancer treatment,
• 64% advanced metastatic or terminal disease
• 59% at all disease stages.

 Because assessment of cancer pain is not routinely done, this is your first stop! Ask about it and assess for cancer pain and the suffering it causes. It is common.

If you treat the back ground pain, the breakthrough pain may reduce in frequency and severity. Treat the background pain principles are:

• Use the mouth
• Use the clock
• Use the ladder
• Individualise therapy
• Pay attention to detail

Once the background pain is managed, then treat the breakthrough pain esp using short acting opioids which might include various routes like sublingual, buccal, oral transmusocal routes.

Always use antineuropathic agents early because up to 25% of cancer pain may be neuropathic in nature. Bone metastases are also common and should be managed with antineuropathic agents amongst other therapeutic options like radiotherapy, radioisotopes and bisphosphonates.

Interventional therapies can be used in refractory cases of cancer pain.

10. Chronic joint pain

Here is something that may change the way you manage chronic joint pain:

Recent advances have shed additional light on the pathophysiology of osteoarthritic pain, highlighting the contribution of central pain pathways together with the sensitisation of peripheral joint receptors and changes of the nociceptive process induced by local joint inflammation and structural bone tissue changes. Thus, a neuropathic pain component may be predominant in individuals with minor joint changes but with high levels of pain refractory to analgesic treatment, providing an alternative explanation for osteoarthritic pain perception.

This means that in a subset of osteoarthritis patients neuropathic pain will feature. This is supported by a growing amount of evidence suggesting that the pain in osteoarthritis has a neuropathic component in some of our patients.

Therefore the use of centrally acting pain medications may have a benefit on reducing osteoarthritic pain. The ineffective pain management and the increasing rates of disability associated with OA mandate for change in our treatment paradigm.

Here is that reference and link if you are interested: Dimitroulas T, Duarte RV, Behura A, Kitas GD, Raphael JH. Neuropathic pain in osteoarthritis: a review of pathophysiological mechanisms and implications for treatment. Semin Arthritis Rheum. 2014 Oct;44:145-54.

This was a big article but I felt compelled to write it in one sitting. I hope you enjoyed it and learnt something from it. Apologies for typos.