SF | CPD: NEUROLOGY
May 2021 | Vol. 21 No. 5 www.medicalacademic.co.za
This article was independently sourced by Specialist Forum.
Pain in the brain
The International Association of Pain updated their definition of neuropathic pain (NP) in 2018. According to the new definition, NP is caused by a lesion or disease of the somatosensory nervous system. The old definition described it as ‘pain initiated or caused by a primary lesion, dysfunction or transitory perturbation of the peripheral or central nervous system (CNS)’.1
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imited data are available on the prevalence of NP in South Africa. International studies estimate that the prevalence of NP is between 7%-8% in the general population. However, if conditions such as diabetes (26%), herpes zoster/ shingles (19%), and postsurgical pain (10%) are included in estimates, the incidence is much higher. Furthermore, 35% of patients with HIV experience NP.1,2,3,7
What causes neuropathic pain? Patients often use words such as burning, pins and needles (paresthesia), tingling, numbness, electric shocks/shooting, crawling (formication), itching, and intolerance to temperature, to describe their experiences. 3 In more advanced cases, patients may describe pain arising from stimuli that are not usually painful (eg allodynia) or pain from
normally painful stimuli that is out of proportion to what would be expected (eg hyperalgesia). 3 Numerous causes of NP have been identified and can be broadly categorised into peripheral and central pain. The most common cause of peripheral is traumatic nerve injury (either from an accident or surgery). 3,4 Other causes of peripheral NP include for example diabetic peripheral polyneuropathy, chemotherapy-induced peripheral neuropathy,
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