Towards an Objective Approach of traumatic and non-traumatic chronic neck pain

Determination of the severity of complaints of patients with chronic traumatic
and non-traumatic neck pain is difficult because of its multifarious nature.
Clinical assessment is either based on functional impairments (e.g. diminished
range of motion, loss of strength) or on subjective symptoms like pain, fatigue
and diminished concentration. Especially subjective symptoms like disturbances
in postural stability, eye movement control and diminished concentration are
difficult to quantify objectively. However, neurophysiologic developments may
provide a method to quantify these *sensorimotor symptoms*. In previous studies
it was hypothesized that sensorimotor dysfunction may be caused by altered
proprioception in the cervical spine. Although straightforward measurement of
proprioception is still not possible, neurophysiologic research revealed that
the cervico-ocular reflex (COR) receives sensory input from neck
proprioception. Changes in COR are likely to reflect changes in neck
proprioception.
Our hypothesis is that reflexive eye movement measurements can assist to make
the connection between functional impairments and symptoms for chronic neck
pain patients. Recording of eye reflexes might help to objectively assess the
severity of complaints of neck pain patients.

The main objective is to develop an objective symptom profile of chronic neck
pain patients which addresses more facets of the health problem, including
sensorimotor dysfunction. The first stage is the establishment of an objective
quantification of sensorimotor dysfunction.

Questions:
1. Is there a significant difference between the gain (ratio between eye and
stimulus movement) of the cervico-ocular reflex (COR), the vestibulo-ocular
reflex (VOR) and the optokineticreflex (OKR) in subjects (aged 18-60) with and
without chronic neck pain?
2. Is there a correlation between the synergy of the gain of the eye reflexes
(COR, VOR and OKR) and cervical functionality (range of motion and joint
reposition error)?
3. What is the relationship between degree of synergy of the gain of the eye
reflexes (COR, VOR and OKR) and improved impairments (VAS, SF36, Neck
Disability Index, EQ-5D, Trail making test a;b and Stroop test)?
4. Can the degree of synergy of the gain of the eye reflexes (COR, VOR and OKR)
be influenced by a therapeutic intervention (multidisciplinary rehabilitation
program)?
5. Does a change in the synergy of the gain of the eye reflexes (COR, VOR and
OKR) by a therapeutic intervention influence the improved impairments (VAS,
SF36, Neck Disability Index, EQ-5D, Trail making test a&b and Stroop test) with
a clinical important change?
6. Is the degree of synergy of the gain of the eye reflexes (COR, VOR and OKR)
in subjects with a traumatic neck pain different to the degree of synergy of
the gain of subjects with non-traumatic neck pain?

The objective described above will be investigated in a longitudinal
intervention study of 60 patients with neck impairments of traumatic and
non-traumatic origin between the age of 18 and 60 years. All patients included
will first receive usual care (e.g. physiotherapy) (non-intervention group) and
later multidisciplinary therapy (intervention group) .The multidisciplinary
therapy will be performed by therapists and psychologists of the Spine & Joint
Centre.
All patients are included by a diagnostic screening performed by medical
doctors of the Spine & Joint Centre. Our measurements will not interfere with
the multidisciplinary therapy, nor influence any other medical care.
All patients will be measured four times:
The non-intervention group will be measured twice with an interval of eight
weeks while they are waiting for the start of the therapy.
As baseline measurement of the intervention group the second measurement at the
end of the waiting period is used. The second measurement will be after eight
weeks of multidisciplinary therapy. The last measurement will be three months
after the finishing of the therapy period. At the Spine & Joint Centre, the
patients will be asked to fill in questionnaires.

In the present therapy protocol of the Spine & Joint Centre, cognitive
behavioural principles are applied to stimulate patients to adopt adequate
behaviour aimed at physical recovery. The program, which is no isolated study
design, but part of regular care, consists of 16 sessions of 3 hours each, over
an 8-week period (total of 48 hours). Patients are divided into groups of 6
patients accompanied by three therapists and a psychologist. Each session
includes training time (1 hour), a group lesson (1 hour) and individual
coaching of the patient (1 hour). The program is based on the most recent
state of the art en is partly adopted from *Whiplash, Headache and Neck
Pain* (Jull et al., 2007). Beside this treatment no other therapy is given.

There are no risks related to this study. There are no related physical of
psychological side effects to the measurements.
The burden of participating is just the invested time. The subjects with neck
pain undergo four times measurements which last approximately an hour each. By
combining the moment of measuring with other appointments at the Spine & Joint
Centre, the extra time of travelling will be minimized.