On the Origin of Pain - the 'Pain Channel' Hypothesis.

Theories of pain have traditionally attributed the sensory experience of pain to the brain. We present here a new hypothesis on the origin of pain which is based on a novel approach to the management of persistent pain. We call it the 'pain channel' hypothesis of the origin of pain.

The "axillary tunnel": an anatomic reappraisal of the limits and dynamics of spread during brachial plexus blockade.

Background: Various anatomic factors have been described as affecting the distribution of a solution injected around the brachial plexus. Using computerized axial tomography dye studies, we introduce a new concept.

Methods: Ten patients with brachial plexus catheters sited using the bent needle supraclavicular technique were studied.

The sheath of the brachial plexus: fact or fiction?

Background: The concept of the axillary "sheath" has been a central tenet of brachial plexus regional anesthesia for many years. Recent investigations have cast doubt on its nature and existence. This study further examines the issue.

A magnetic resonance imaging analysis of the infraclavicular region: can brachial plexus depth be estimated before needle insertion?

In this study we examined the anatomy of the infraclavicular region to assess the possibility of estimating brachial plexus depth before performing an infraclavicular block, by using readily identifiable landmarks such as the coracoid process (CP) and the clavicle (CL). Four parasagittal planes across the infraclavicular region were analyzed in 21 individual series of magnetic resonance imaging studies. Measurements included distance to the plexus from the skin of the anterior chest wall, position of the plexus relative to the CL, and clavicular width.