P - NEUROPATHIC PAIN Tools & Resources

Diagnosis of neuropathic pain, including its causes, should be informed by:

1. a complete patient history
2. a physical examination
3. the International Spinal Cord Injury Pain (ISCIP) Classification system
4. investigations.

A complete patient history should focus on determining the nature of pain symptoms that could indicate potentially reversible causes, aggravators and/or mimics of neuropathic pain, and the consequences of pain on function and quality of life. Essential elements of a complete patient history are the following:

1. Nature of pain: onset or triggering event, position or location, quality (for example, burning, electric shock-like), radiation, severity, timing (for example, constant or intermittent, spontaneous, or evoked) and aggravating or alleviating factors
2. Changes in neurologic status: changes in strength, sensation, or spasticity
3. Associated symptoms: ask about red flag signs and symptoms such as vasomotor instability (Red flags are serious underlying conditions that may cause, aggravate or mimic NP. Red flag indicators are symptoms and signs that suggest that a particular condition may be present. It is essential to identify red flags, as effective treatment could significantly improve or eliminate NP if managed appropriately and if left untreated may have serious adverse consequences for the patient).
4. Screening for interference: interference with sleep, physical function and mood or emotional function
5. Recent changes in health: new medical diagnoses such as diabetes and other conditions predisposing to polyneuropathy
6. Additional historical components: based on presentation and suspected etiology.

The physical examination should include, at a minimum, neurologic, skin, and musculoskeletal examinations. Additional systems should be examined based on symptoms. Essential elements of the physical examination are the following:

1. Vital signs
2. International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI)
3. Reflexes, tone
4. Range of motion assessment of extremities, joint swelling or redness
5. Visual inspection of the skin for integrity
6. Calf measurement to assess for deep vein thrombosis
7. ISNCSCI autonomic standards.

Additional physical examination components may be included based on presentation, for example:

1. Primary abdominal region pain: abdominal screening examination
2. Respiratory involvement: chest assessment
3. Autonomic symptoms: assessment for etiology of autonomic dysreflexia (noxious stimuli).

Determining a specific etiology can be difficult and may require additional investigations. The selection of these investigations is geared towards the diagnoses of greatest clinical likelihood, and diagnostic tests are based on the presentation. It is essential to image the appropriate area of the spinal cord for all patients with any change in neurologic status, such as changes in neurologic level, tone, and reflexes. If any suspicion of urinary tract infection exists, it is important to perform a urinalysis and culture and sensitivity. Patients with primary abdominal region pain should have an abdominal ultrasound, radiography, or computed tomography as necessary to determine the source of the pain; blood work may include lipase, amylase, liver enzymes and kidney function tests. Signs and symptoms suggesting respiratory involvement could lead to further investigations such as chest assessment or radiography. In patients in whom pulmonary embolism is suspected, a computed tomography angiogram or ventilation/perfusion lung scan should be performed. Other investigations should be performed based on the differential diagnosis, as appropriate.

Assess for serious underlying conditions (red flags) that may cause, aggravate, or mimic neuropathic pain and that require further investigation and prompt medical review. (CANPAIN DIAG 2016, p.S10; Level C)

Red flags are serious underlying conditions that may cause, aggravate, or mimic neuropathic pain. Red flag indicators are symptoms and signs that suggest that a particular condition may be present. It is essential to identify red flags, as effective treatment could significantly improve or eliminate neuropathic pain if managed appropriately and, if left untreated, may have serious adverse consequences for the patient.

Red flag table: https://www.nature.com/articles/sc201689/tables/1

Assess and manage psychosocial factors (yellow flags) that may contribute to pain-related distress and disability. (CANPAIN DIAG 2016, p.S10; Level C)

Addressing psychosocial factors (yellow flag conditions) is essential for treatment success in an individual who has pain after SCI. Yellow flags can complicate and exacerbate the presentation of neuropathic pain and may contribute to pain-related distress and disability. Examples of yellow flag conditions or factors include the following:

1. Depressive symptoms
2. Altered appetite
3. Poor motivation to complete daily activities or work because of pain
4. Decreased participation in valued activities
5. Pre-existing pain problems with evidence of poor adjustment
6. Avoidance of activities associated with pain
7. Extensive periods of rest or bed rest
8. Evidence of catastrophic thinking, preoccupation with pain prognosis, significant anxiety, and panic symptoms
9. Use and dependence on alcohol or illicit substances
10. Increasing opioid dependence or misuse
11. Disruption of sleep quality and/or duration
12. Lack of support from family members towards pain and activity.

Address patient concerns, expectations and needs as part of the neuropathic pain assessment. (CANPAIN DIAG 2016, p.S11; Level C)

It is vital to remember that pain is subjective, and individuals differ in their expectations of treatment and needs with regards to pain. As a result, it is important to develop rehabilitation goals and the treatment plan in partnership with the patient. Goals of treatment, such as improvement in function, reduction in pain severity and improvement in mood, should be reviewed before initiating a particular treatment. Consider using SMART (Specific, Measurable, Agreed upon, Realistic and Time-based) goal methodology when setting treatment goals. Establishing specific treatment targets also allows evaluation of treatment benefits.

Standardized evaluation of treatment response should be carried out by the healthcare team at regular intervals. (CANPAIN DIAG 2016, p.S11; Level C)

Monitoring a patient’s response to treatment, including efficacy, tolerance, dose-escalation, and side effects, is vital to modifying any suboptimal treatments. Such modification should be performed as rapidly as feasible. Adverse events need to be balanced against treatment benefits when determining whether to continue treatment, and discussion with the patient should inform decision-making.

Comparing treatment targets with achieved outcomes helps determine whether continued use of a treatment is worthwhile. It is also important to assess domains of intensity, mood, and function when determining treatment success. In addition to the International Spinal Cord Injury Pain Basic Data Set (ISCIPBDS v2.0), supplementary standardized measures such as the opioid risk tool may be used to evaluate outcomes not contained in the data set. As some medications to treat neuropathic pain, such as opioids, are subject to misuse, it is important to monitor for aberrant behaviour, as this may indicate either misuse or inadequate pain control. The National Opioid Use Guideline Group provides additional recommendations for opioid use.

The evaluation of treatment response should include assessment of changes in pain intensity, mood and function using the International Spinal Cord Injury Pain Basic Data Set (ISCIPBDS) v2.0. Evaluation also includes an assessment of adverse events, aberrant behaviour, and compliance. (CANPAIN DIAG 2016, p.S11; Level C)

Monitoring a patient’s response to treatment, including efficacy, tolerance, dose-escalation, and side effects, is vital to modifying any suboptimal treatments. Such modification should be performed as rapidly as feasible. Adverse events need to be balanced against treatment benefits when determining whether to continue treatment, and discussion with the patient should inform decision-making.

Comparing treatment targets with achieved outcomes helps determine whether continued use of a treatment is worthwhile. It is also important to assess domains of intensity, mood and function when determining treatment success. In addition to the ISCIPBDS v2.0, supplementary standardized measures, such as the opioid risk tool, may be used to evaluate outcomes not contained in the data set. As some medications to treat neuropathic pain are subject to misuse, such as opioids, it is important to monitor for aberrant behaviour, as this may indicate either misuse or inadequate pain control. The National Opioid Use Guideline Group provides additional recommendations for opioid use.

International Spinal Cord Injury Pain Basic Data Set (ISCIPBDS) v2.0: https://www.iscos.org.uk/uploads/sitefiles/Data%20Sets/Papers%20from%20Spinal%20Cord%20-Data%20Sets/ISCIBDS_Pain_2.pdf

All patients with new-onset or worsening pain need to be reassessed. (CANPAIN DIAG 2016, p.S11; Level C)

It is critical to pay particular attention to late-onset pain or sudden worsening of chronic pain. New-onset or worsening chronic neuropathic pain may require exclusion of treatable causes of the pain, assessment for new-onset red flag or yellow flag conditions and a full neuropathic pain assessment.