Spinal Segmental Sensitization (SSS) is a hyperactive state of the spinal cord caused by irritative foci sending nociceptive impulses from a sensitized damaged tissue to dorsal horn neurons. The clinical manifestation of dorsal horn sensitization includes hyperalgesia of the dermatome, pressure pain sensitivity of the sclerotome and myofascial trigger points within the myotomes, which are supplied by the sensitized spinal segment. Shah et al. (2005) found that active myofascial trigger points present lower pressure pain threshold when compared to people with no pain or the presence of only latent trigger points. They also demonstrated the distinct in-vivo biochemical milieu of muscle with significant elevated levels of substance P, calcitonin gene-related peptide (CGRP), bradykinin, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), serotonin, and norepinephrine in the vicinity of the active myofascial trigger point at the upper trapezius muscle. Overall, pH was significant lower in the active trigger point. Treatment rationale and techniques may evolve from this information, and should be taken into account when dealing with chronic patients with amplified pain responses. Irritative foci in the form of myofascial trigger points (MTrPs) located within the associated myotomes and tender spots in the supra/interspinous ligaments (SSL/ISL) of the segment frequently lead to SSS. The mechanism consists of the nociceptive stimuli generated in the sensitized areas bombarding the dorsal horn of the spinal cord. This causes central nervous system sensitization with resultant hyperalgesia of the dermatome and sclerotome and spreads from the sensory component of the spinal segment to the anterior horn cells, which control the myotome within the territory of the SSS. The importance of SSS is emphasized by the fact that it is consistently associated with musculoskeletal pain. For example, thoracic SSS facilitates and perpetuates abdominal pain and somatovisceral symptoms commonly mimicking GI disorders. The development or amplified activity of MTrPs is one of the clinical manifestations of SSS.
Failure to recognize and diagnose SSS often leads to only temporary deactivation of MTrPs, since physical therapy and trigger point injection procedures are aimed at treating the peripheral MTrPs without addressing the segmental dysfunction. This may lead to transient benefit rather than long term relief because MTrPs and their associated symptoms frequently recur.
Eradication of the sensitized spinal segment by the technique of paraspinous block (PSB) with 1% Lidocaine effectively desensitizes (reverses to normal sensitivity) the SSS by blocking the nociceptive impulses from the SSL/ISL and prevents afferent bombardment of the dorsal horn. Subsequent needling and infiltration of the SSL/ISL with 1% Lidocaine as well as needling and infiltration of MTrPs in the myotome of the territory of the sensitized spinal segment leads to long term relief of neuromusculoskeletal pain and dysfunction.
Because Spinal Segmental Sensitization (SSS) is a hyperactive state of the spinal cord caused by irritative foci sending nociceptive impulses from a sensitized damaged tissue to dorsal horn neurons is important to take away the prymary irritaitve foci.
If is not possible to deliver needling and injections other therapies can be used to desensitize the segment and to treat it.
That can be possible i.e. if the patient has some specific allergies, if needling and injection are not covered by insurance or by the national health system, or if the patient doesnt like or doesent want to be injected.
These therapies must be used following the prof Fischer’s concept of the sensitized segment.
After the sensitized segment is diagnosed and it is detected the immediate cause of pain, we can treat both the vertebral segment and the irritative foci with these other therapies. Therapies already been prooven to be effective in non specific pain are, spinal manipulation, acupuncture, massage, and antiinflammatory drugs. Other than this we can t forget that one of the most important desensitization is due to antinflammatory agents.