Nociplastic Pain in Multiple Sclerosis Spasticity: Dermatomal Evaluation, Treatment with Intradermal Saline Injection and Outcomes Assessed by 3D Gait Analysis: Review and a Case Report

Abstract

Nociplastic pain has been introduced by the IASP as a third category of pain, distinct from nociceptive and neuropathic pain. Pathogenetically, it is considered to be a continuum of these two types of pain after becoming chronic. Repetitive peripheral painful stimulation causes a central sensitization with hypersensitivity of the corresponding spinal metamer or brain region. Therefore, signs of altered nociception, such as allodynia, may be found on the tissues of the related dermatome, myotome and sclerotome, and characterize nociplastic pain. This kind of pain was found in over 20% of people with multiple sclerosis (pwMS), a demyelinating autoimmune disease that affects the central nervous system. Nociplastic pain may be an amplifier of spasticity, the main pyramidal symptom that affects about 80% of pwMS. This article details the case of a 36-year-old woman with multiple sclerosis who was affected by spasticity and non-specific pain of the lower limbs, disabling on walking. Previous analgesic and muscle relaxant treatment had no benefits. The diagnosis of nociplastic pain on the cutaneous tissue of the anterolateral region of the left thigh and its treatment with intradermal normal saline injection on the painful skin area showed immediate and lasting effects on pain and spasticity, improving significantly the patient’s balance and walking, as assessed by a 3D motion analysis and rating scales.

The Psychosocial Characteristics and Somatosensory Function of Children and Adolescents Who Meet the Criteria for Chronic Nociplastic Pain

“…With the recent introduction of the terminology of nociplastic pain, there is still limited data characterizing this pain mechanism and its prevalence. A study on adults with multiple sclerosis and chronic pain identified that 50% had nociplastic pain with or without neuropathic pain, 34 while a study on adults with symptomatic hip OA observed that 23% of their cohort displayed neuropathic, nociplastic, or mixed pain. 35 Nevertheless, 40% of our sample were classified as possible nociplastic pain.…”

What Do We Know about Nociplastic Pain?

“…It is important to exclude, if possible, the presence of metastatic disease [ 94 ]. Numerous other health conditions are mentioned in the literature as potentially associated with NcplP, including rheumatoid arthritis [ 13 , 95 ], osteoarthritis [ 96 , 97 ], gluteal syndrome [ 98 ], electrical injury [ 99 ], multiple sclerosis [ 43 , 100 ], cerebral palsy and spina bifida [ 101 ], Parkinson’s disease, [ 26 ] and post-COVID pain [ 102 , 103 ]. Some articles also mention endometriosis as a cause of NcplP [ 104 , 105 ].…”

“…Unfortunately, it is limited to CRPS and fibromyalgia, so its use requires further research [ 76 , 115 ]. Some researchers report potential benefits of procedural types of treatment such as steroid injections for temporomandibular disorders [ 27 ], normal saline injections [ 100 ], transcranial direct current stimulation, and repetitive transcranial magnetic stimulation [ 87 ]. Although they were reported to be less effective in NcplP in comparison to other types of pain [ 27 ]; they can be administered if other interventions have been ineffective [ 55 ].…”

Microbiological and Physiological Effects of Pain

“…Specifically, central sensitization, a likely underpinning of the nociplastic pain mechanism, is a key factor in fibromyalgia [ 59 ]. It has also been demonstrated that a subset, over 20%, of patients suffering from multiple sclerosis (MS) suffer from nociceptive pain as part of their disease [ 60 ]. Moreover, this is especially significant as the most common pain type in MS was nociceptive pain which was suffered by about 41% of patients, and other common pain types were mixed and included nociplastic pain, demonstrating its significant prevalence in the disease [ 61 ].…”