[Expression of Wnt5a in dorsal root ganglia in rat model of chronic compression of dorsal root ganglia].

OBJECTIVE: To investigate the role of Wnt5a in the mechanism of radiculopathy and the relation between Wnt5a and tumor necrosis factor α (TNF-α) by observing the change of the expression of Wnt5a in the rat model of chronic compression of dorsal root ganglia (CCD). METHODS: A total of 192 adult male Sprague Dawley rats were allocated into 4 groups: shame group (group A, n = 48), CCD group (group B, n = 48), CCD + saline group (group C, n = 48), and CCD + etanercept group (group D, n = 48). An L-shaped needle (about 3.5 mm in length, 0.6 mm in diameter) was inserted into the L5 intervertebral foramen, and the dorsal root ganglia (DRG) was compressed by the needle to prepare the CCD model in groups B, C, and D, and then normal saline (5.5 mg/kg) or etanercept was injected intraperitoneally in groups C and D. The intervertebral foramen was exposed in group A. The mechanical pain threshold of the posterior paw was tested by the von Frey filaments at 1, 3, 5, and 7 days after operation; the expressions of Wnt5a protein and mRNA were detected at 3 and 7 days after operation by immunohistochemical staining and RT-PCR, respectively. RESULTS: The mechanical pain threshold of groups B and C was significantly lower than that of groups A and D, and in group D than in group A (P < 0.05), but no significant difference was found between groups B and C (P > 0.05). The Wnt5a positive cells and the mRNA expression of Wnt5a at 7 days were significantly more than those at 3 days in groups B, C, and D (P < 0.05). The Wnt5a positive cells and the mRNA expression of Wnt5a in groups B and C were significantly more than in groups A and D, and in group D than in group A (P < 0.05), but no significant difference was shown between groups B and C (P > 0.05). CONCLUSION: The expression of Wnt5a in the DRG is increased after CCD. The expression of Wnt5a in the DRG is decreased after the administration of the inhibitor of TNF-α.

[Effect of neurolysis on intractable greater occipital nerve neuralgia].

OBJECTIVE: To investigate the effect of neurolysis on intractable greater occipital nerve neuralgia. METHODS: From March 1998 to August 2005, twenty-six patients suffering from intractable greater occipital nerve neuralgia were treated. There were 12 males and 14 females with an average age of 52 years (ranged 38-63 years). The disease course was 3-7 years. Sixteen cases had a long duration of work with bowing head, 5 cases symptoms appeared after trauma, and others had no identified causes. The visual analogue scales (VAS) scoring was 6.0 to 9.5, averaged 8. 6. Seven cases were treated by apocope of obliquus capitis inferior under general anaesthesia and 19 cases were treated by neurolysis of greater occipital nerve under local anaesthesia. The compression mass were examined. RESULTS: Symptoms ameliorated or disappeared in 26 cases immediately after operation. The wounds healed by first intention. The pathological results of the removal mass included lymph node (3 cases), neurilemmoma (2 cases) and scar (5 cases). The VAS scoring of 26 cases was 0 to 5 (average, 2) 3 days after operation. Twenty-three cases were followed up for 1 to 3 years. The VAS scoring of 23 cases was 0 to 4.5 ( average, 1.9) 1 months after operation. Only two cases recurred and the symptoms were ameliorated. Pain aggavated after tiredness and reliveed after oral anti-inflammatory analgesics in 6 cases. No relapse occurred in the others. CONCLUSION: The complete neurolysis of greater occipital nerve (including apocope of obliquus capitis inferior, release between the cucullaris and semispinalis) which make the greater occipital nerve goes without any compression is the key point to treat intractable greater occipital nerve neuralgia.