Table 1 Description of three studies included in a systematic review on the effect of spinal manipulation on ‘brain function’, comparing spinal manipulation to a sham intervention
1st author Yr Ref | Design | Type of study subjects | Number of study subjects (males/females) | -Age (range) -Mean | -Type of spinal manipulation -Type of control -Sham | How was cerebral activity measured? | When was cerebral activity measured? | Clinical outcomes assessed (measurement tool and time of assessment) |
|---|---|---|---|---|---|---|---|---|
Spars 2017 [9] | Randomized controlled trial | Symptomaic: volunteers (unknown origin) with mechanical neck pain < 6 weeks of duration | 24 (4 / 8) manipulation group / (4 / 8) sham group | -? /? -36 manipulation group / 40 sham group | -HVLA midthoracic (X1) -‘No’ control -Sham: similar positioning of the subject and investigator’s hands which were placed across the skin with minimal pressure (to mimic the HVLA procedure) | Blood oxygenation level-dependent signal (in response to noxious stimuli) | Before After: immediately | Pain intensity (11-point numerical pain rating scale) (before spinal manipulation or sham procedures and after the final fMRI) |
Lelic 2016 [14] | Crossover controlled trial (order of interventions randomized) | “Subclinical neck/spinal pain”: volunteers (origin unknown) with recurrent spinal ache, pain or stiffness and evidence of spinal dysfunction but who did not yet sought treatment for this and pain free at the time of the study. | 19 (9 / 10) | -? -26 | -HVLA (where needed, in any spine level or sacroiliac joints, nb unknown _ may be at several levels) -‘No’ control -Sham: passive and active movements of the head, spine, and body, similar to what was done for HVLA intervention, without loading and thrust | SEP amplitudes: N30 peaks Strength of brain sources: contralateral somatosensory cortex, prefrontal cortex, cingulate cortex, and bilateral secondary somatosensory cortex | Before After: exact time unknown | None |
Baarbé 2018 [15] | Randomized controlled trial | “Subclinical neck/spinal pain”: volunteers (unknown origin) with recurrent mild neck pain and muscle tension, but minimal acute pain on the day of testing and who never sought treatment for this neck complains. | 27 (6 / 8) intervention group / (5 / 8) sham group | -18–27 intervention group / 19–24 sham group -21 (for both groups) | -HVLA cervical (X2 to 4 per subject) -‘No’ control -Sham: neck gently moved into lateral flexion and rotation in a similar manner to the actual neck manipulation, without applying the HVLA thrust | Cerebellar inhibition | Before After: exact time unclear (said to be immediately after motor acquisition task, i.e. cerebellar inhibition was re-measured about 20 min after spinal manipulation) | None |