## 2 Case Presentation
### Treatment  
The first treatment (visit two) consisted of dry needling to muscles of the neck identified to have active TrPs on examination (Table 2). Since the patient was on anti-coagulants, precaution was taken in determining needling depth and degree of manipulation. Although asymptomatic bruising is a potential risk, significant bleeding is uncommon when using appropriate technique with needling (regardless of needle gauge) in the treatment of patients on optimal regimens of anticoagulant therapy [54]. Needles were inserted and intermittently rotated within TrPs to stimulate endogenous pain modulation without seeking to elicit local twitch responses [55; 56]. After TrPDN, manual cervical traction and soft tissue mobilization to needed muscles was applied to assist with pain modulation. However, the patient reported continued pain when pressure was applied over the muscles near the right C2 and C3 facet joint and articular pillar region. She had a very slender neck, and it was easy to compress the muscles, feel bone, and apply pressure to the CAP at C2 and C3, which elicited her pain. At this stage, posteroanterior (PA) joint mobilization was considered. However, spinal non-thrust mobilization is known for eliciting non-segmental analgesic effects [57], and the patient's symptoms were more localized to the right C2-C3 segmental levels. In addition, PA mobilization to the upper cervical spine produces extension movement in the upper neck, and cervical extension increased the patients' pain on examination [58]. Therefore, to provide a direct sensory stimulus to the bones (sclerotomes), PDN was applied to the CAP at the C2 and C3 levels using shallow insertion of needles followed by several taps into each bone within a 3-4 mm area (Figure 3), as previously described by [PERSON] [1]. Compression of the overlying muscles during the procedure  
Figure 2: Differential diagnosis, according to American Physical Therapy Association’s revised clinical practice guidelines for neck pain [53]. Abbreviations: ROM, range of motion. allowed the use of shorter needles, as longer needles may lead to unwanted tissue trauma, can bend more easily, and can reduce the feel of needle palpation to the bone [59]. No adverse reaction occurred, and the patient exhibited very good tolerance to the treatment. The patient received an informative handout about dry needing and then scheduled a follow up session for three days later. At the third visit, her resting pain intensity on the NPRS was 0 and cervical AROM was improved with pain only at end range movement (Table 3). No bruising was noted following the previous treatment. The cervical lateral glide test again reproduced pain on the right with radiation to the occupit. Palpation over the C3 articular pillar did reproduce the same pain. Treatment at session three consisted of PDN to the CAP at C2 and C3, followed by the manual therapy that was applied in the previous session. The patient was instructed on a home exercise program (HEP) directed at improving cervical AROM and strengthening of postural and deep neck flexor muscles. Additionally, she was educated on modified use (folding) of her current feather pillows to promote neutral cervical spine alignment in the side-lying position to reduce neck pain (Table 2). A recent systematic review reported that the effects of different pillow types on sleep quality is inconclusive, but maintaining neutral neck positions at rest with proper pillow use is beneficial [60]. During a follow-up visit one week later (visit 4), she was pain-free at rest and with movement; no further dry needling or manual treatment was given. Cervical AROM was greatly improved in all previously limited directions (Table 3). Figure 3: Description of PDN technique and potential mechanisms. (A) The patient was positioned in side-lying to expose the lateral neck in a neutral position. (B) Palpation began at the mastoid process of the temporal bone and progressed to the prominent transverse process of C1.