SIMR is committed to leveraging its years of expertise in pain research, to develop precise solutions for patients under various conditions.
Pain is an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage (IASP, 2020). Globally, pain is a major public health problem.
Neuropathic pain (NP) is caused by a lesion or disease of the somatosensory system. It is one of the most incapacitating pains and remains a significant unmet medical need (Colloca et al., 2017) . Approximately 7- 8% of the general population are affected, with prevalence rising with age and certain medical conditions (D. Bouhassira, 2019).
Based on the anatomical location of the injury or disease, NP is classified into peripheral neuropathic pain (pNP) and central neuropathic pain. Common types of pNP include postherpetic neuralgia (PHN), painful diabetic peripheral neuropathy (PDPN), and painful radiculopathy. Central neuropathic pain may develop following a stroke or spinal cord injury, as well as in conditions such as multiple sclerosis and other neurological or metabolic disorders.
pNP is a common condition in clinical practice, and its incidence continues to rise, particularly in aging populations.
Ø Postherpetic neuralgia ( PHN )
PHN is the most common and important complication associated with herpes zoster infections, causing prolonged suffering and poor quality of life in affected populations. The primary symptom of PHN is intermittent or continuous nerve pain in an area of the skin previously affected by shingles. The pain may come and go or be continuous.
The global incidence of PHN ranges from 3.9 to 42/100,000 person-years. In China, its prevalence is reported at 2.3% , with 29.8% of herpes zoster patients developing PHN (van Hecke et al., 2014; Yang et al., 2019). In some individuals, PHN can last for weeks or months. However, in about one in five people, the pain lasts for more than one year after the shingles rash has healed (Lu et al., 2018; Cleveland Clinic).
Ø Painful diabetic peripheral neuropathy ( PDPN )
PDPN is the most common chronic complication of diabetes. It is typically characterized by spontaneous burning pain in the feet, which is often difficult to treat effectively and has a significantly impact on patients’ lifestyle and quality of life.
According to the Chinese Expert Consensus on the Diagnosis and Treatment of Peripheral Neuropathic Pain (2020), 16% of diabetic patients are affected by PDPN. Alarmingly, many patients remain undiagnosed (12.5%) and untreated (39%). The International Diabetes Federation (IDF) reports that in 2021, the diabetes prevalence in China for individuals aged 20-79 was 10.6%, affecting 141 million people, with over 22 million individuals potentially affected by PDPN.
Ø Trigeminal neuralgia ( TGN )
TGN is a disorder characterized by recurrent unilateral brief electric shock-like pains, abrupt in onset and termination, limited to the distribution of one or more divisions of the trigeminal nerve and triggered by innocuous stimuli (ICHD-3, 2018) . It is a highly debilitating disease that affects patients' basic functions such as speaking, eating, drinking, or even light touch to the face, resulting in a severe decrease in quality of life (Lambru et al., 2021).
Studies suggest that the prevalence of TGN in the general population is estimated between 0.01% and 0.3%. While TGN can develop at any age, more than 90% of cases occur after the age of 40, with the peak onset typically between 50 and 60 years (IASP, 2013).
Ø Painful radiculopathy
Painful radiculopathy is persistent or recurrent pain caused by a lesion or disease involving the cervical, thoracic, lumbar, or sacral nerve roots (IASP, 2019). It is typically characterized by spontaneous pain, hyperalgesia, and sensory abnormalities in the affected nerve root distribution area. The pain can be persistent or paroxysmal and decribed as stabbing, burning, tearing, electric shock-like, or pricking sensations. It often leads to functional impairment.
Painful lumbosacral radiculopathy (PLSR) is a subtype of painful radiculopathy. In the general population, the annual prevalence of lumbosacral radicular pain ranges between 9.9% and 25% (Konstantinou et al., 2013). PLSR significantly affects patients' quality of life, resulting in reduced workforce productivity and excessive strain on healthcare resources.
