Cervico-ocular Reflex Is Increased in People With Nonspecific Neck Pain

Classification of short and long term mild traumatic brain injury using computerized eye tracking

Accurate, and objective diagnosis of brain injury remains challenging. This study evaluated useability and reliability of computerized eye-tracker assessments (CEAs) designed to assess oculomotor function, visual attention/processing, and selective attention in recent mild traumatic brain injury (mTBI), persistent post-concussion syndrome (PPCS), and controls. Tests included egocentric localisation, fixation-stability, smooth-pursuit, saccades, Stroop, and the vestibulo-ocular reflex (VOR). Thirty-five healthy adults performed the CEA battery twice to assess useability and test-retest reliability. In separate experiments, CEA data from 55 healthy, 20 mTBI, and 40 PPCS adults were used to train a machine learning model to categorize participants into control, mTBI, or PPCS classes. Intraclass correlation coefficients demonstrated moderate (ICC > .50) to excellent (ICC > .98) reliability (p < .05) and satisfactory CEA compliance. Machine learning modelling categorizing participants into groups of control, mTBI, and PPCS performed reasonably (balanced accuracy control: 0.83, mTBI: 0.66, and PPCS: 0.76, AUC-ROC: 0.82). Key outcomes were the VOR (gaze stability), fixation (vertical error), and pursuit (total error, vertical gain, and number of saccades). The CEA battery was reliable and able to differentiate healthy, mTBI, and PPCS patients reasonably well. While promising, the diagnostic model accuracy should be improved with a larger training dataset before use in clinical environments.

Academic performance and musculoskeletal pain in adolescents with uncorrected vision problems

BACKGROUND

Undetected vision problems are common in school children, and a prevalence of up to 40% has previously been reported. Uncorrected vision and lack of optimal eye wear can have a significant impact on almost all aspects of everyday life, such as development and learning, academic performance, pain and discomfort, and quality of life. This study aimed to analyze the relationship between uncorrected vision problems, educational outcomes, and musculoskeletal pain symptoms.

METHODS

A total of 152 school children (15.1 ± 0.8 years, mean ± SD; 40% males) were included in the study. All participants were recruited from a free-of-charge school vision testing program in Kathmandu, Nepal. Academic grades were collected from the school records of the participants' nationwide final grade examinations. A questionnaire was used to record the use of digital devices, screen time, and associated symptoms, including musculoskeletal pain (Wong-Baker FACES Pain Rating Scales).

RESULTS

A total of 61 children (40%) had uncorrected vision, with a cycloplegic refraction of SER - 0.53 ± 0.52 (mean ± SD). Children with uncorrected vision had significantly more third division grades (26 vs. 9%, p = 0.004) and shoulder pain in general/during screen use (66 vs. 43/40%, p = 0.008/0.003; 2.1/1.9 vs. 1.1/1.0 mean pain score, p = 0.002/0.001) compared with children with normal vision. Sex based subanalyses showed that only girls with uncorrected vision had more third division grades (25 vs. 4%, p = 0.006), and only boys with uncorrected vision had more shoulder pain in general/during screen use (76 vs. 28/31%, p < 0.001; 2.2/2.4 vs. 0.7 mean pain score, p < 0.001), compared with children with normal vision.

CONCLUSIONS

The results of this study showed that even small refractive errors may impact educational outcomes and musculoskeletal pain in adolescents. Most of the participating children had low myopia, easily corrected with glasses. This suggests that regular eye examinations are important in school children, and there is a need for raised awareness among parents, and school- and healthcare personnel.

Cervico-Ocular and Vestibulo-Ocular Reflexes in Subclinical Neck Pain and Healthy Individuals: A Cross-Sectional Study

Alterations in neck sensory input from recurrent neck pain (known as subclinical neck pain (SCNP)) result in disordered sensorimotor integration (SMI). The cervico-ocular (COR) and vestibulo-ocular (VOR) reflexes involve various neural substrates but are coordinated by the cerebellum and reliant upon proprioceptive feedback. Given that proprioception and cerebellar processing are impaired in SCNP, we sought to determine if COR or VOR gain is also altered. COR and VOR were assessed using an eye-tracking device in 20 SCNP (9 M and 11 F; 21.8 (SD = 2.35) years) and 17 control (7 M and 10 F; 22.40 (SD = 3.66) years) participants. COR gain (10 trials): A motorized chair rotated the trunk at a frequency of 0.04 Hz and an amplitude of 5° while participants gazed at a circular target that disappeared after three seconds. VOR gain (30 trials): Rapid bilateral head movements away from a disappearing circular target while eyes fixated on the last observed target. Independent t-tests on COR and VOR gain were performed. SCNP had a significantly larger COR gain (p = 0.006) and smaller VOR gain (p = 0.487) compared to healthy controls. The COR group differences suggest an association between proprioceptive feedback and SMI, indicating COR may be a sensitive marker of altered cerebellar processing.

Video-oculographic measures of eye movement control in the smooth pursuit neck torsion test can classify idiopathic neck pain patients from healthy individuals: A datamining based diagnostic accuracy study

BACKGROUND

Idiopathic neck pain patients frequently experience oculomotor disfunctions with deficits in eye movement control between neutral and neck torsion position (SPNT test) being commonly investigated in clinical and research settings.

OBJECTIVES

The aim of the study was to determine accuracy of SPNT test in classifying idiopathic neck pain patients.

DESIGN

a datamining based diagnostic accuracy study.

METHODS

The study was conducted on a referred sample of 38 chronic neck pain patients from orthopaedic outpatient clinic and 40 healthy controls. Video-oculography was used to study gain and SPNT_diff during SPNT test under three target movement velocities and amplitudes and two different angles of neck torsion. A Naïve Bayesian predictive model was used to classify neck pain patients based on gain or SPNT_diff.

RESULTS

Gain during two target movement profiles at velocities of 30°s^-1 and amplitudes of 30° and 40° under 45° of neck torsion presented with highest area under the curve (0.837), specificity (92%), sensitivity (94%), highest true positive and lowest false negative predicted value. Highest area under the curve (0.760), specificity (50%), sensitivity (71%), highest true positive and lowest false negative values were observed for SPNT_diff at velocities of 30°s^-1 and amplitude of 30° applying 45° of neck torsion.

CONCLUSION

SPNT test provides useful diagnostic tool for classifying neck pain patients when using single or combination of two target movement profiles. Neck torsion of 45° as opposed to 30° should be used during SPNT test when investigating patients with neck pain disorders.

Laboured reading and musculoskeletal pain in school children - the role of lifestyle behaviour and eye wear: a cross-sectional study

Background

Lifestyle behaviour in children and adolescents has become increasingly sedentary and occupied with digital work. Concurrently, there has been an increase in the prevalence of headache, neck- and low back pain, which are leading causes of disability globally. Extensive near work and use of digital devices are demanding for both the visual system and the upper body head-stabilizing musculature. Uncorrected vision problems are present in up to 40% of Nordic school children, and a lack of corrective eye wear may cause eyestrain, musculoskeletal pain and headache. The aim of this study was to investigate associations between laboured reading, musculoskeletal pain, uncorrected vision, and lifestyle behaviours in children and adolescents.

Methods

This was a cross-sectional study with a total of 192 Norwegian school children aged 10–11 and 15–16 years. As a part of a school vision testing program, the children completed an online questionnaire about general and ocular health, socioeconomic status, academic ambition, near work and related symptoms, upper body musculoskeletal pain, and physical and outdoor activities.

Results

The 15–16-year-olds had a more indoor, sedentary, digital-based lifestyle with higher academic demands, compared with the 10–11-year-olds. Concurrently, reading became more laboured and upper body musculoskeletal pain increased with age. Girls reported more symptoms, higher academic ambitions, and more time spent on schoolwork and reading, compared with boys. Non-compliance in wearing prescribed eye wear (glasses or contact lenses), increased use of near digital devices, and experiencing visual stress (glare) were positively associated with laboured reading and upper body musculoskeletal pain.

Conclusions

A screen-based lifestyle with high academic demands challenges the ability to sustain long hours of static, intensive near work. Extensive near work tires the visual system and upper body musculature and provokes laboured reading and musculoskeletal pain symptoms. This study emphasizes the importance of regular eye examinations in school children, and the need to raise awareness among children, parents, and school- and health personnel about the importance of optimal vision and visual environment for academic performance and health.

Effectiveness of deep cervical fascial manipulation and yoga postures on pain, function, and oculomotor control in patients with mechanical neck pain: study protocol of a pragmatic, parallel-group, randomized, controlled trial

INTRODUCTION

Mechanical neck pain (MNP) is a commonly occurring musculoskeletal condition that is usually managed using electrical modalities, joint mobilization techniques, and therapeutic exercises, but has limited evidence of their efficacy. Pathology (densification) of the deep cervical fascia that occurs due to the increased viscosity of hyaluronic acid (HA) may induce neck pain and associated painful symptoms of the upper quarter region. Fascial manipulation (FM) and yoga poses are considered to reduce the thixotropy of the ground substances of the deep fascia and improve muscle function. The purpose of this study is to investigate the effect of FM and sequential yoga poses (SYP) when compared to the usual care on pain, function, and oculomotor control in MNP.

METHODS

This FaCe-Man trial will recruit 160 patients with subacute and chronic mechanical neck pain diagnosed using predefined criteria. Participants will be randomized to either the intervention group or the usual care group, using a random allocation ratio of 1:1. Patients in the intervention group will receive FM (4 sessions in 4 weeks) and SYP (12 weeks) whereas the standard care group will receive cervical mobilization/ thoracic manipulation (4 sessions in 4 weeks) and therapeutic exercises (12 weeks). The primary outcome is the change in the numeric pain rating scale (NPRS). The secondary outcomes include changes in the patient-specific functional scale and oculomotor control, myofascial stiffness, fear-avoidance behavior questionnaire, and elbow extension range of motion during neurodynamics test 1.

DISCUSSION

If found effective, FM along with SYP investigated in this trial can be considered as a treatment strategy in the management of mechanical neck pain. Considering the magnitude of the problem, and the pragmatic and patient-centered approach to be followed, it is worth investigating this trial.

TRIAL REGISTRATION

ClinicalTrials.gov CTRI/2020/01/022934 . Registered on January 24, 2020 with ctri.nic.in. Clinical Trials Registry - India.

Headache and musculoskeletal pain in school children are associated with uncorrected vision problems and need for glasses: a case-control study

Musculoskeletal pain and headache are leading causes of years lived with disability, and an escalating problem in school children. Children spend increasingly more time reading and using digital screens, and increased near tasks intensify the workload on the precise coordination of the visual and head-stabilizing systems. Even minor vision problems can provoke headache and neck- and shoulder (pericranial) pain. This study investigated the association between headaches, pericranial tenderness, vision problems, and the need for glasses in children. An eye and physical examination was performed in twenty 10–15 year old children presenting to the school health nurse with headache and pericranial pain (pain group), and twenty age-and-gender matched classmates (control group). The results showed that twice as many children in the pain group had uncorrected vision and needed glasses. Most children were hyperopic, and glasses were recommended mainly for near work. Headache and pericranial tenderness were significantly correlated to reduced binocular vision, reduced distance vision, and the need for new glasses. That uncorrected vision problems are related to upper body musculoskeletal symptoms and headache, indicate that all children with these symptoms should have a full eye examination to promote health and academic performance.

Slower reaction and response times and impaired hand-eye coordination in individuals with neck pain

BACKGROUND

Neck pain is associated with sensorimotor dysfunction. Research is sparse of the effect of neck pain on reaction and response times and hand-eye coordination.

OBJECTIVES

To investigate hand and foot reaction and response times and hand-eye coordination in individuals with neck pain and to determine any relationships with clinical features of neck pain.

METHODS

Sixty individuals with neck pain and 60 controls of similar age and gender were recruited. Tests of simple reaction and response time were measured on the dominant hand and foot. Hand-eye coordination was measured by tracing a variety of coordination patterns with different levels of difficulty. Clinical features measured were intensity and duration of pain, and neck disability.

RESULTS

Hand and foot reaction and response times were significantly slower in the neck pain group compared to controls (all p < 0.001). The neck pain group took longer to trace the hand-eye coordination task at the hardest level (p = 0.03). Neck disability scores correlated with hand reaction time (r = 0.4, p = 0.005) and time taken in hand-eye coordination tasks (r = 0.2 for all levels, p < 0.05). Reaction and response times were correlated with time taken in the hand-eye coordination test (r = 0.2-0.4, p < 0.01).

CONCLUSIONS

Individuals with neck pain had slower hand and foot reaction and response times and impaired hand-eye coordination, suggesting deficits in sensorimotor function. Training speed, as a function of acuity, and hand-eye coordination might be considered in clinical assessment. Further research is needed to identify potential underlying mechanisms of the slower and less well coordinated movement.

Misperception of Visual Vertical in Peripheral Vestibular Disorders. A Systematic Review With Meta-Analysis

OBJECTIVE

The main aim was to assess the misperception of visual verticality (VV) in patients with peripheral vestibular disorders (PVD) in comparison with healthy controls. As secondary objectives, we checked if vestibular, visual, and somatosensory postural pathways can be affected in patients with PVD as well as the characteristics of PVD that could influence on the VV perception.

METHODS

A systematic review with meta-analysis was carried out. The bibliographic search was performed in January, 2020 in PubMed, Scopus, Web of Science (WOS), CINAHL, SciELO. Two reviewers selected the studies that met the inclusion criteria, extracted data, and assessed the methodological quality using the Newcastle-Ottawa Scale (NOS). The VV perception was assessed in two meta-analysis according the used test: The Subjective Visual Vertical test (SVV) or the Rod and Frame Test (RFT) in comparison with healthy subjects. The Standardized Mean Difference (SMD) and its 95% Confidence Interval (95% CI) was used to estimate the pooled effect. Publication bias was assessed using the Egger's test and Trim and Fill Method.

RESULTS

Thirty-four studies were included reporting 3,524 participants. PVD patients showed a misperception of the VV with SVV (SMD = 1.510; 95%CI: 1.190-1.830) and the RFT (SMD = 0.816; 95% CI: 0.234-1.398) respect healthy controls. A subgroup of patients in the acute phase (SMD = 2.5; 95%CI: 2.022-2.978) and who underwent a vestibular surgery (SMD = 2.241; 95%CI: 1.471-3.011) had the greater misperception of VV.

CONCLUSION

Patients with PVD show an alteration in the perception of VV, being greater in the acute phase and after a vestibular surgery. Laryngoscope, 131:1110-1121, 2021.

Neck pain associated with clinical symptoms in dizzy patients-A cross-sectional study

OBJECTIVE

Many patients suffer from concurrent neck pain and dizziness. The aim of this study was to describe the clinical symptoms and physical findings in patients with concurrent neck pain and dizziness and to examine whether they differ from patients with dizziness alone.

METHODS

Consecutive patients with dizziness and neck pain were recruited from an ear-nose-throat department and a spine clinic. They were divided into three groups: patients with dizziness only (n = 100), patients with dizziness as their primary complaint and additional neck pain (n = 138) and finally, patients with neck pain as their primary complaint accompanied by additional dizziness (n = 55). The patients filled in questionnaires regarding their symptom quality, time-course, triggers of dizziness and the Vertigo Symptom Scale Short Form. The physical examination included Cervical Range of Motion, American College of Rheumatology (ACR) Tender Points, Cervical Pressure Pain Thresholds and Global Physiotherapy Examination 52-Flexibility.

RESULTS

Both neck pain groups were more likely to have a gradual onset of dizziness symptoms, more light-headedness, visual disturbances, autonomic/anxiety symptoms, decreased cervical range of motion, decreased neck and shoulder flexibility and increased number of ACR tender points compared with patients with dizziness alone. The group having dizziness as their primary complaint and also reporting neck pain had the highest symptom severity and tended to report rocking vertigo and increased neck tenderness. The group with neck pain as their primary complaint was more likely to report headache.

CONCLUSION

Neck pain is associated with certain dizziness characteristics, increased severity of dizziness and increased physical impairment when compared with dizzy patients without neck pain.

Frequency-dependent deficits in head steadiness in patients with nonspecific neck pain

Motor control impairments are reported in patients with nonspecific neck pain but the particular deficits in underlying regulatory systems are not known. Head steadiness is controlled both by voluntary and reflex systems that are predominantly effective within different frequency intervals. The aim of the present study was to investigate within which frequency range(s) potential motor control deficits may reside. The ability to keep the head stationary in space in response to unpredictable perturbations was tested in 71 patients with nonspecific neck pain and 17 healthy controls. Participants were exposed to pseudorandom horizontal rotations across 10 superimposed frequencies (0.185-4.115 Hz) by means of an actuated chair in three conditions; with a visual reference, and without vision with, and without a cognitive task. Below 1 Hz, patients kept the head less stable in space compared to healthy controls. Between 1 and 2 Hz, the head was stabilized on the trunk in both groups. Patients kept the head more stable relative to the trunk than relative to space compared to healthy controls. This was interpreted as higher general neck muscle co-activation in patients, which may be explained by altered voluntary control, or/and upregulated gamma motor neuron activity which increases the contribution of reflex-mediated muscle activation. Alternatively, increased muscle activity is secondary to vestibular deficits.

Traditional physical therapy exercises combined with sensorimotor training: The effects on clinical outcomes for chronic neck pain in a double-blind, randomized controlled trial

OBJECTIVE

This study examined the effects of combining traditional physical therapy exercises with sensorimotor training on joint position sense, pain, muscle endurance, balance and disability in patients with chronic, non-specific neck pain.

DESIGN

Double-blind, randomized controlled trial.

SUBJECTS

A total of 53 patients with chronic non-specific neck pain were randomized to either traditional or combined exercise groups.

INTERVENTIONS

All patients received 12 sessions of supervised intervention 3 times per week. The traditional group performed traditional exercises, and the combined exercise group performed sensorimotor training in addition to traditional exercises.

OUTCOME MEASURES

Joint position sense, pain, neck flexor muscle endurance test, 10 Meter Walk Test, step test, and the Neck Disability Index.

RESULTS

The combined exercise group showed significantly greater improvement compared to the traditional group in joint position sense during extension, flexion, right rotation, the 10 m walk test with head turn, and the step test. Pain intensity, muscle endurance, and disability improved in both groups. Additionally, there was a higher degree of effect on muscle endurance in the combined exercise group compared to a moderate effect in the traditional group.

CONCLUSIONS

A combination of sensorimotor training with traditional physical therapy exercises could be more effective than traditional exercises alone in improving joint position sense, endurance, dynamic balance and walking speed.

Altered trunk head co-ordination in those with persistent neck pain

BACKGROUND

Decreased neck motion and sensorimotor deficits have been identified in those with neck pain. It is thought that these might be related to altered reflex mechanisms between the neck, eyes and the vestibular system. Trunk, head co-ordination might also be altered in neck pain.

OBJECTIVES

This study investigated trunk head co-ordination ability in subjects with neck pain compared to asymptomatic controls.

METHOD

Twenty-four subjects with persistent neck pain and twenty-six age and gender matched healthy controls performed 3 trials of 3 trunk movements whilst trying to keep the head still - (1) alternate trunk movement to the left and right (2) trunk movement to the left (3) trunk movement to the right. Wireless motion sensors positioned over the sternum and the forehead measured trunk and head range and velocity of motion.

ANALYSIS

ANOVA was used to compare trunk and head range and velocity of motion during the 3 tasks.

RESULTS

Neck pain subjects had significantly less trunk movement (p < 0.05) and velocity (p=<0.02) as well as significantly increased head movement (p=<0.03) during most tasks compared to control subjects.

DISCUSSION

The results of the study suggest that neck pain subjects have difficulty moving their trunk independently of their head. They are less able to keep the head still while moving the trunk and perform the tasks more slowly. These findings might be related to altered reflex activity of the cervico-collic reflex and sensorimotor control. Further research is required.

Influence of neck torsion on near point convergence in subjects with idiopathic neck pain

BACKGROUND

People with neck pain (NP) experience sensorimotor and oculomotor deficits thought to be due to abnormal cervical afferent input. Convergence insufficiency (CI) measured by near point convergence (NPC) may be a feature in NP and neck torsion might help to differentiate a cervical cause.

OBJECTIVES

This study aimed to investigate repeatability and reliability of NPC in neutral and torsion and compare between idiopathic NP and controls along with correlation to the Convergence Insufficiency Symptom Survey (CISS).

DESIGN

Comparative cross sectional observational study.

METHOD

A Royal Airforce (RAF) Rule measured NPC with the neck in neutral and in 45° torsion to the left and right in 42 subjects. A revised 15 item CISS was also completed. The average of 3 trials in each position and torsion difference were calculated. Within one week, NPC inter-rater and test-retest reliability was evaluated in 10 subjects.

RESULTS

A significant NPC torsion difference was demonstrated in participants with NP compared to controls (P = 0.01). No significant differences were seen for NPC values in neutral (P = 0.73). High inter-rater reliability (ICC = 0.95) and repeatability (ICC = 0.84) was obtained. No correlations were present between the CISS and NPC measures (r ≤ 0.18).

CONCLUSIONS

NPC is impaired in neck torsion compared to neutral in NP supporting a cervical afferent cause. NPC, measured using the RAF Rule, is a reliable and repeatable measure and can be used to assess NPC and CI in those with NP. Objective rather than self-reported measures should be used to examine CI in NP.

The influence of cervical movement on eye stabilization reflexes: a randomized trial

To investigate the influence of the amount of cervical movement on the cervico-ocular reflex (COR) and vestibulo-ocular reflex (VOR) in healthy individuals. Eye stabilization reflexes, especially the COR, are changed in neck pain patients. In healthy humans, the strength of the VOR and the COR are inversely related. In a cross-over trial the amplitude of the COR and VOR (measured with a rotational chair with eye tracking device) and the active cervical range of motion (CROM) was measured in 20 healthy participants (mean age 24.7). The parameters were tested before and after two different interventions (hyperkinesia: 20 min of extensive active neck movement; and hypokinesia: 60 min of wearing a stiff neck collar). In an additional replication experiment the effect of prolonged (120 min) hypokinesia on the eye reflexes were tested in 11 individuals. The COR did not change after 60 min of hypokinesia, but did increase after prolonged hypokinesia (median change 0.220; IQR 0.168, p = 0.017). The VOR increased after 60 min of hypokinesia (median change 0.155, IQR 0.26, p = 0.003), but this increase was gone after 120 min of hypokinesia. Both reflexes were unaffected by cervical hyperkinesia. Diminished neck movements influences both the COR and VOR, although on a different time scale. However, increased neck movements do not affect the reflexes. These findings suggest that diminished neck movements could cause the increased COR in patients with neck complaints.

Dizziness, Unsteadiness, Visual Disturbances, and Sensorimotor Control in Traumatic Neck Pain

Synopsis There is considerable evidence to support the importance of cervical afferent dysfunction in the development of dizziness, unsteadiness, visual disturbances, altered balance, and altered eye and head movement control following neck trauma, especially in those with persistent symptoms. However, there are other possible causes for these symptoms, and secondary adaptive changes should also be considered in differential diagnosis. Understanding the nature of these symptoms and differential diagnosis of their potential origin is important for rehabilitation. In addition to symptoms, the evaluation of potential impairments (altered cervical joint position and movement sense, static and dynamic balance, and ocular mobility and coordination) should become an essential part of the routine assessment of those with traumatic neck pain, including those with concomitant injuries such as concussion and vestibular or visual pathology or deficits. Once adequately assessed, appropriate tailored management should be implemented. Research to further assist differential diagnosis and to understand the most important contributing factors associated with abnormal cervical afferent input and subsequent disturbances to the sensorimotor control system, as well as the most efficacious management of such symptoms and impairments, is important for the future. J Orthop Sports Phys Ther 2017;47(7):492-502. Epub 16 Jun 2017. doi:10.2519/jospt.2017.7052.