Consider for a moment the diagram and its accompanying explanation below:

This is a diagrammatic representation of part of a myofascial trigger point showing two motor endplates (MEPs) and juxtapositional contraction knots (CKs). A neurovascular bundle (NB) containing motor nerves (MNs), nociceptive and sensory afferents (SAs) and blood vessels (BVs) with closely associated sympathetic fibres. Note that in a normal muscle fibre (NMF) the sarcomeres are of equal length, but in a muscle fibre containing a contraction knot there is compensatory lengthening of sarcomeres on either side.

Given the close proximity of TPs and consequent dry needling intervention to the autonomic nervous system, it should come as no surprise that patients regularly experience ‘odd’ sensations during and immediately after dry needling. This is especially the case when intense, clinically relevant TPs are needled for the first time. These sensations can include dizziness/nausea, feelings of alternating heat and cold and extreme tiredness. Unfortunately, it is difficult to predict with a high degree of confidence how patients will react.

My patients often enthusiastically recall their particular experiences on follow-up consultations. However, in instances when I have not prepared them adequately for these, their displeasure is palpable. We simply must remember to inform patients, both before and also after dry needling that these occurrences may occur and to stress that they are not to be feared.

Reference:

Mike  Cummings , Peter  Baldry. Regional myofascial pain: diagnosis and management. Best Practice & Research Clinical Rheumatology Volume 21, Issue 2 2007 367 – 387. http://dx.doi.org/10.1016/j.berh.2006.12.006.