Mechanistic Foundations and Clinical Management of Neuropathic Pain: A Pathophysiological Review for the Aotearoa Healthcare Landscape

Living with nerve pain can often feel like trying to navigate a landscape where the map no longer matches the terrain. For many, this sensation is not just a simple ache; it is a complex series of signals that the body is struggling to interpret. While conventional descriptions of pain often focus on temporary injuries, neuropathic pain is different. It arises when the nervous system itself is affected by a lesion or a disease, leading to signals that can feel unpredictable and, at times, overwhelming.

Understanding the biological “why” behind these sensations can offer a sense of clarity. In Aotearoa New Zealand, where nearly 8 percent of the population lives with some form of neuropathic pain, moving toward a more personalised way of managing it is becoming a priority for both patients and clinicians. Research suggests that by looking at the underlying mechanisms, we can move beyond just treating symptoms and begin to address the root causes of the discomfort.

The biology of persistent signals

When we look at the mechanisms behind nerve pain, two common paths often emerge: metabolic changes, such as those seen in diabetes, and physical nerve injury.

Metabolic changes and the polyol pathway

One way this happens, particularly for those with diabetes, is through a process known as the polyol pathway. When blood sugar levels stay high, the body begins a series of metabolic changes that can affect the health of the nerves. Excess glucose is converted into sorbitol, a substance that cannot easily move out of the cells. This creates a kind of osmotic stress, leading to cellular swelling and oxidative damage within the nerve fibres. Over time, this can lead to a state of chronic ischaemia, where the nerves do not receive the oxygen they need to function correctly, causing the nerve endings to become unstable.

Ectopic discharge and nerve injury

Traumatic nerve injury follows a different pattern. When a nerve is damaged by surgery or an accidental injury, the damaged fibres may begin to fire spontaneously. This is sometimes referred to as ectopic discharge. The nervous system becomes hyper-responsive, and the threshold for feeling pain is lowered. This process, known as central sensitisation, means the spinal cord and brain become so primed to protect the body that even a light touch or a gentle breeze can be perceived as painful.

Recognising your sensory pattern

Many people find that while they may share a diagnosis with others, their experience of pain is entirely unique. Modern research uses a concept called sensory phenotyping to help explain this variety. By identifying specific signs and symptoms, clinicians can better predict how someone might respond to certain treatments. Many people find they fall into one of three general patterns:

• Sensory Loss: This involves a noticeable numbness or loss of temperature sensation, often accompanied by a paradoxical spontaneous pain. Some research suggests these individuals may respond differently to tricyclic antidepressants or opioids than other groups.
• Thermal Hyperalgesia: In this pattern, the nerves remain highly sensitive to heat or cold. This is often thought to reflect an irritable nociceptor, where surviving nerve fibres are in a state of constant hyperactivity due to ion channel changes.
• Mechanical Hyperalgesia: This is defined by a high sensitivity to light touch or pressure, known as allodynia. This pattern is frequently associated with central sensitisation in the spinal cord.

Recognising which pattern feels most familiar can be a helpful step in a consultation, as it allows for a more tailored approach to care.

Grounded steps for daily management

Managing a long-term condition is rarely about a single, quick fix. It is more often a journey of trial, observation, and adjustment. While medication is a common starting point, many find that small, grounded shifts in lifestyle can help restore a sense of control.

Pacing and energy awareness

For those living with fatigue, the “boom and bust” cycle (doing too much on a good day and paying for it later) is a common hurdle. Pacing involves breaking tasks into smaller, manageable pieces and scheduling rest before it becomes a necessity. This approach validates that rest is an active and essential part of care.

Gentle movement and the brain

Physical activity remains a cornerstone of wellbeing, but it does not have to be intense. Recent studies have looked at balance training, which may help by upregulating certain inhibitory circuits in the brain, such as GABA-mediated pathways, to dampen the volume of pain signals. Low-impact movements like yoga or short walks are often more realistic and helpful for long-term consistency.

The role of the endocannabinoid system

In recent years, many clinicians in New Zealand have begun to consider medicinal cannabis for those who have found first-line treatments like gabapentinoids or tricyclic antidepressants unsuitable. The endocannabinoid system is a regulatory network in the body that helps manage how we process pain. Receptors known as CB1 and CB2 are located throughout the nervous system; when activated, they may help inhibit the release of excitatory signals, potentially easing the intensity of the signals reaching the brain.

A 2025 systematic review found that approximately 79 percent of randomised controlled trials observed a statistically significant decrease in neuropathic pain scores following cannabinoid treatment (effect sizes vary). Furthermore, a New Zealand audit of 400 patients observed that CBD was well tolerated and associated with improvements in self-reported quality of life.

Moving forward with clarity

Managing nerve pain requires patience and a collaborative relationship with your healthcare team. Whether you are exploring new clinical options or refining your daily routine, it is important to remember that your pace is the right one. By focusing on the biological drivers of your specific experience, it becomes possible to find strategies that support your independence and wellbeing.

Reference List

1. International Association for the Study of Pain. (2024, November 12). Terminology | International Association for the Study of Pain. International Association for the Study of Pain (IASP). https://www.iasp-pain.org/resources/terminology/
2. Tim. (2022, November 1). Cannabinoids could provide relief from neuropathic pain. Cannasouth. https://www.cannasouth.co.nz/2022/cannasouth-research-shows-cannabinoids-could-provide-relief-for-thousands-of-new-zealanders-from-debilitating-neuropathic-pain/
3. Managing patients with neuropathic pain – BPJ 75 May 2016. (n.d.). https://bpac.org.nz/bpj/2016/may/pain.aspx
4. Scholz, J., & Woolf, C. J. (2007). The neuropathic pain triad: neurons, immune cells and glia. Nature Neuroscience, 10(11), 1361–1368. https://doi.org/10.1038/nn1992
5. Colloca, L., Ludman, T., Bouhassira, D., Baron, R., Dickenson, A. H., Yarnitsky, D., Freeman, R., Truini, A., Attal, N., Finnerup, N. B., Eccleston, C., Kalso, E., Bennett, D. L., Dworkin, R. H., & Raja, S. N. (2017). Neuropathic pain. Nature Reviews Disease Primers, 3(1), 17002. https://doi.org/10.1038/nrdp.2017.2
6. Marchevsky, E., Guaycochea, S., Bendersky, M., & González, S. (2021). Fenotipos y diagnóstico en dolor neuropático. Multidisciplinary Pain Journal. https://doi.org/10.20986/mpj.2021.1008/2021
7. Health Navigator NZ. (2021). Living with neuropathic pain. https://healthify.nz/assets/Legacy/3677/helping-patients-live-with-neuropathic-pain-nps.pdf
8. An overview of medicinal cannabis for health practitioners – bpacnz. (n.d.). https://bpac.org.nz/2022/medicinal-cannabis.aspx
9. Guindon, J., & Hohmann, A. (2009). The endocannabinoid system and pain. CNS & Neurological Disorders – Drug Targets, 8(6), 403–421. https://doi.org/10.2174/187152709789824660
10. Choi, J., Li, G., Stephens, K. L., Timko, M. P., & DeGeorge, B. R. (2024). The use of cannabinoids in the treatment of peripheral neuropathy and neuropathic pain: a systematic review. The Journal of Hand Surgery, 50(8), 954–965. https://doi.org/10.1016/j.jhsa.2024.09.015
11. Gulbransen, G., Xu, W., & Arroll, B. (2020). Cannabidiol prescription in clinical practice: an audit on the first 400 patients in New Zealand. BJGP Open, 4(1), bjgpopen20X101010. https://doi.org/10.3399/bjgpopen20x101010