Presence of NGF and its receptor TrkA in degenerative lumbar facet joint specimens.

In a preliminary study, the recurrent presence of nervous terminations was demonstrated with optical microscopy in several slides of degenerative lumbar facet joints and surrounding soft tissues. The purpose of this study was to prove the presence of NGF (nerve growth factor) and its receptor TrkA (tyrosine kinase receptor) with immunofluorescence. The peri/articular tissues were harvested from the lumbar facet joints of ten patients surgically treated for degenerative diseases. There were seven females (one bilateral) and two males whose mean age at surgery was 72 years (range, 67-80 years). The affected levels were L3-L4 in two cases and L4-L5 in seven cases (one bilateral). All specimens were fixed in formalin, dehydrated and enclosed in paraffin. From each specimen, four slides were obtained. Two slides were employed for the search of NGF: one was treated with specific antibodies and marked with FITC (fluorescein isothiocyanate conjugated), and the second slide was for control purposes. It was exposed to FITC, but without prior exposure to the specific antibody. The same procedure was repeated to obtain on two more slides, to repeat the search for Trka with specific antibodies. All the slides were finally studied on a fluoromicroscope. The analysis of these specimens revealed the presence of the neurotrophin (NGF) and its own receptor (TrkA) in all cases: the immunohistochemical reaction between the specimens and the specific antibodies marked with FITC was seen under fluoromicroscopy, but in none of the control cases treated with FITC only. NGF is released by mastocytes, fibroblasts and other cell types involved in the inflammatory processes. The level of peripheral NGF is increased in inflammatory processes, while the administration of exogenous NGF has a hyperalgesic effect on rats and produces muscular pain in humans. Furthermore, NGF produces hypersensitization to heat stimulation in humans and mammals in general. There is considerable evidence showing that the system constituted by the NGF and its high-affinity receptor TrkA plays a fundamental role in the molecular processes underlying the main forms of "persistent" pain. This indicates a possible therapeutic area for the antibodies that could block the NGF/TrkA system, in order to modulate the frequency and the duration of the action potential of nociceptive neurons during chronic inflammation. This study demonstrated the presence of NGF and TrkA in specimens collected from degenerative facet joints, suggesting that specific molecules could be used in order to modulate chronic pain in patients with degenerative lumbar spine.

Spondylolysis of L2 in identical twins.

OBJECTIVE: To discuss the presence of spondylolysis at L2 in identical twins. CLINICAL FEATURES: Twin 61-year-old brothers reported insidious low back pain (LBP) of relatively recent onset. Both engaged in running as their main form of exercise. One had spondylolisthesis and history of significant traumatic incident; the other had no spondylolisthesis but a much more strenuous running regimen. INTERVENTION AND OUTCOME: Both patients underwent a course of chiropractic treatment for mechanical LBP and reported a 50% overall improvement in symptoms. CONCLUSIONS: Spondylolysis at L2 is uncommon, and although a familial component regarding weakness of the pars interarticularis has been demonstrated in the literature, spondylolysis at L2 in twins is extremely rare. Questions remain regarding the cause of spondylolisthesis in patients.

Diagnostic value of cervical somatosensory evoked potentials recorded from the intervertebral discs after median and ulnar nerve stimulation in cervical spondylotic myelopathy.

We have studied the cervical somatosensory evoked potentials (CSEPs) recorded referentially from serial intervertebral discs after stimulation of the median nerve or the ulnar nerve at the wrist in cervical spondylosis. In seven unilateral radiculopathies, the CSEPs evoked by stimulation on the asymptomatic side normally consisted of the P1-N1 and the P2-N2 components, which represented the potentials arising from the white matter and the gray matter, respectively. Of 21 myelopathies, the CSEPs revealed the white matter involvement with conduction block identified by abrupt P1-N1 amplitude reduction in 7, the gray matter involvement identified by P2-N2 amplitude reduction in 3, or a combination of both in 11. The CSEPs were useful not only for determining the level responsible for myelopathy but also for localizing the lesion in the transverse plane of the spinal cord.

Intersegmental sagittal motion in the lower cervical spine and discogenic spondylosis: a preliminary study.

OBJECTIVE: The object of this investigation was to identify any correlation between discogenic spondylosis and the type of motion (normal, hypomobility, hypermobility, paradoxical motion) found in the sagittal plane of the intervertebral motion units of the lower cervical spine. DESIGN AND SETTING: A case control study was performed from the files of 100 patients (ages 15-73) with cervical spine-related symptomatology at the Anglo-European College of Chiropractic Clinic. PATIENTS: The cases were randomly selected from a cohort of patients with normal radiographic anatomy who attended the clinic from 1987-1990 and were known to have cervical spine neutral, flexion and extension lateral radiographs taken. MAIN OUTCOME MEASURES: Extended chi 2 was used to test the observed data. RESULTS: The findings from both the flexion and extension films suggested that intervertebral motion units with and without varying severities of discogenic spondylosis did differ with respect to the type of motion exhibited there (flexion: chi 2 = 39.399, p < .001; extension: chi 2 = 45.7424, p < .001). Intervertebral motion units which had discogenic spondylosis had a greater likelihood of exhibiting motion abnormalities (flexion: chi 2 = 5.665, p < .01; extension: chi 2 = 6.178, p < .01), and all types of motion seemed to be dependent on its severity (flexion: chi 2 = 16.464, p < .01; extension: chi 2 = 15.954, p < .02). In general, normal motion occurred approximately 60% of the time when there was absent or mild discogenic spondylosis and decreased precipitously as moderate and severe amounts of discogenic spondylosis appeared. In global cervical flexion, when there was either little or no discogenic spondylosis and abnormal motion was present, intersegmental hypermobility was predominant. Hypomobility became predominant overall as moderate and severe discogenic spondylosis was found. In global cervical extension, for all severities of discogenic spondylosis when there was abnormal motion, intersegmental hypomobility was predominant. Also of note was the presence of paradoxical motion, which occurred in 11% of the intervertebral motion units without discogenic spondylosis [usually at the C7-T1 intervertebral motion unit (86%)]. CONCLUSIONS: From the data it can be concluded that there are trends which occur with differing amounts of discogenic spondylosis when considering intersegmental cervical sagittal motion. However, additional detailed study is required to corroborate the findings and determine what their clinical significance is.