Upper limb sympathetic blockade following intercostal nerve blocks

Elevated detection thresholds for mechanical stimuli in chronic pain patients: support for a central mechanism

OBJECTIVE

To investigate the relation between pain provoking cervical segments identified by diagnostic dorsal root blockades and elevation of detection thresholds in patients suffering from chronic cervicobrachialgia (CCB).

DESIGN

Quantitative sensory testing (light touch) of the cervical dermatomes using Semmes-Weinstein monofilaments.

SETTING

A university pain clinic.

SUBJECTS

Thirty-nine patients with CCB, with no clinical or diagnostic evidence of radiculopathy or surgically treatable bony lesion and with one main pain-provoking cervical segment identified by diagnostic dorsal root blockades.

OUTCOME MEASURES

Detection thresholds with 95% confidence intervals (95% CI) of pain-provoking segments, compared with surrounding and contralateral segments and with normal values for cervical dermatomes.

RESULTS

Patients' detection thresholds were significantly (p < .001) higher than those for normal subjects: 3.51 (95% CI, 2.71-4.31) and 3.10 (95% CI, 2.34-3.86), respectively. No significant differences existed between the segments. The elevations were systematic. However, thresholds on the painful side were consistently, slightly higher than those on the contralateral side.

CONCLUSION

Supporting earlier studies, results from CCB patients in the present study showed systematic elevation of detection thresholds (low threshold mechanoreceptors), an adaptation in contrast with, but not contradictory to, central sensitization of high threshold neurons in chronic pain.

The management of chronic spinal pain by blockades: a review

This review of the use of blockades in the diagnosis and symptomatic treatment of spinal pain syndromes is based on increasing knowledge of the innervation of the spine as their rationale. Several clinical syndromes related to the spine are considered. Problems in making a correct diagnosis are discussed. Because of the relative aspecificity of signs and symptoms in spinal pain, a substantial part of the diagnosis may rely on test blockades. The place of test and therapeutic blocks is determined as far as possible. Problems of a pain classification system are discussed. Benefit for the patient depends on the following conditions being achieved: correct diagnosis, careful patient selection, the availability of technical equipment (e.g., fluoroscopy), and a well-designed and well-performed technique in experienced hands.

The treatment of chronic thoracic segmental pain by radiofrequency percutaneous partial rhizotomy

Forty-five patients, 12 men and 33 women with an age range of 17 to 88 years (median 52 years), were selected for a posterior thoracic percutaneous partial rhizotomy (PPR) based on the following criteria. Each patient had at least a 6-month history of irradiating pain that followed the segmental pattern of an intercostal nerve and had not responded to conservative treatment. In addition, no causal treatment was available and there was a temporary positive response to an intercostal blockade with lidocaine. In the lower thoracic region (T8-12) PPR was performed with the usual dorsolateral technique; in the upper thoracic region a dorsal approach was used by means of a drill hole made with a Kirschner wire in the vertebral arch. The 45 patients underwent 53 thoracic PPR operations. Patients were evaluated 2 months after treatment. Thirty patients (66.7%) were pain-free: in 11 cases (24.4%) more than 50% improvement was achieved, and in four (8.9%) there was no improvement. Side effects consisting of a transient burning pain or a mild transient sensory loss occurred in eight patients (17.7%). After a follow-up period of 13 to 46 months (median 24 months) results were evaluated in 41 patients; five patients had undergone reintervention. Excellent long-term results were achieved in 20 patients (48.8%), good results in 15 (36.6%), and poor results in six (14.6%). It is concluded, that when conservative treatment fails, thoracic PPR may prove an effective and safe treatment for chronic segmental thoracic pain.