When range of motion is not enough: Towards an evidence-based approach to medico-legal reporting in whiplash injury

Video-nystagmographic evidence in more than 700 consecutive cases of road traffic whiplash injury

PURPOSE

Whiplash injury is a frequent traumatic lesion occurring mainly in road accidents, which may also cause dizziness severe enough to impact everyday life. Vestibular examination is routinely performed on these patients, although the role of the neuro-otologist is still not clearly defined. The main endpoint of this study was to describe the videonystagmography (VNG) evidence in a large cohort of patients who underwent road traffic whiplash injury.

METHODS

717 consecutive patients who reported whiplash-associated disorders due to a road traffic accident underwent clinical examination and VNG.

RESULTS

Patients with saccadic test latency anomalies more frequently complained of vertigo, nausea and cochlear symptoms after trauma (p = 0.031, 0.028 and 0.006), while patients with bilateral vestibular weakness at caloric stimulation more often displayed neck pain after trauma (p = 0.005). Patients complaining of positional or cochlear symptoms or with accuracy anomalies at the saccadic test were significantly older than those with no positional, no cochlear symptoms and without accuracy anomalies (p = 0.022, p = 0.034 and p = 0.001). Patients with bilateral vestibular hypofunction were significantly younger (p < 0.001).

CONCLUSIONS

VNG evidence, particularly vestibular function and saccadic tests, may be related to damage in the cervical region due to whiplash trauma. These findings suggest that neuro-otologic examination may play a role in properly identifying those who suffer damage caused by whiplash trauma, and in characterizing the severity and prognosis of whiplash-associated disorders.

Road traffic whiplash injury in the elderly: Clinical and video-nystagmographic features

PURPOSE

Whiplash is a type of trauma typically caused by a rear end collision in a road accident. About one in two patients who experience whiplash report dizziness and balance problems, which can severely affect their activities in daily life. In industrialized countries, the number of elderly people with a driving license has increased in recent years. The aims of the present study were to describe the video-nystagmographic features in a consecutive series of elderly patients experiencing whiplash injury in a road accident, comparing them with similar injuries in a group of young adults.

METHODS

Twenty-seven patients aged 65 years or more and a control group of 32 young adults between 18 and 21 years old were retrospectively selected. All patients underwent oto-vestibular assessment and video-nystagmography.

RESULTS

After whiplash trauma, vertigo was more common in elderly patients with decreased peak velocity during the saccadic ocular motricity test (p = 0.017) and with evidence of bilateral vestibular hypofunction after caloric stimulation (p = 0.033). Comparing the two age groups, neck pain after the trauma was reported significantly more by young adults (p = 0.003), who also showed more frequently bilateral vestibular hypofunction (p = 0.025).

CONCLUSION

Clinical and instrumental findings seem to support the hypothesis of a functional lesion to the brainstem regions after a whiplash injury. There is an undeniable need, however, for tools capable of objectively assessing the functional or anatomical damage resulting from whiplash-associated disorders, for both clinical and medico-legal reasons.

Does a tow-bar increase the risk of neck injury in rear-end collisions?

INTRODUCTION

Does a tow-bar increase the risk of neck injury in the struck car in a rear-end collision? The rear part of a modern car has collision zones that are rendered nonoperational when the car is equipped with a tow-bar. Past crash tests have shown that a car's acceleration was higher in a car equipped with a tow-bar and also that a dummy placed in a car with a tow-bar had higher peak acceleration in the lower neck area.

METHOD

This study aimed to investigate the association between the risk of neck injury in drivers and passengers, and the presence of a registered tow-bar on the struck car in a rear-end collision. We performed a merger of police reports, the National Hospital Discharge Registry, and the National Registry of Motor Vehicles in Denmark. We identified 9,370 drivers and passengers of whom 1,519 were diagnosed with neck injury within the first year after the collision. We found a statistically insignificant 5% decrease in the risk of neck injury in the occupants of the struck car when a tow-bar was fitted compared to when it was not fitted (hazard ratio=0.95; 95% confidence level=0.85-1.05; p=0.32). The result was controlled for gender, age, and the seat of the occupant. Several other collision and car characteristics and demographic information on the drivers and passengers were evaluated as confounders but were not statistically significant.

CONCLUSIONS

The present study may serve as valuable input for a meta-analysis on the effect of a tow-bar because negative results are necessary in order to avoid publication bias.

Chronic neck pain patients with traumatic or non-traumatic onset: Differences in characteristics. A cross-sectional study

BACKGROUND AND AIMS

Patients with chronic neck pain can present with disability, low quality of life, psychological factors and clinical symptoms. It is unclear whether patients with a traumatic onset differ from those with a non-traumatic onset, by having more complex and severe symptoms. The purpose of this study was to investigate the clinical presentation of chronic neck pain patients with and without traumatic onset by examining cervical mobility, sensorimotor function, cervical muscle performance and pressure pain threshold in addition to the following self-reported characteristics: quality of life, neck pain and function, kinesiophobia, depression, and pain bothersomeness.

METHODS

This cross-sectional study included 200 participants with chronic neck pain: 120 with traumatic onset and 80 with non-traumatic onset. Participants were recruited from physiotherapy clinics in primary and secondary health care. For participants to be included, they were required to be at least 18 years of age, have had neck pain for at least 6 months, and experienced neck-related activity limitation as determined by a score of at least 10 on the Neck Disability Index. We conducted the following clinical tests of cervical range of motion, gaze stability, eye movement, cranio-cervical flexion, cervical extensors, and pressure pain threshold. The participants completed the following questionnaires: physical and mental component summary of the Short Form Health Survey, EuroQol-5D, Neck Disability Index, Patient-Specific Functional Scale, Pain Bothersomeness, Beck Depression Inventory-II, and TAMPA scale of kinesiophobia. The level of significance for all analyses was defined as p<0.01. Differences between groups for the continuous data were determined using either a Student's t-test or Mann Whitney U test.

RESULTS

In both groups, the majority of the participants were female (approximately 75%). Age, educational level, working situation and sleeping patterns were similar in both groups. The traumatic group had symptoms for a shorter duration (88 vs. 138 months p=0.001). Participants in the traumatic group showed worse results on all measures compared with those in the non-traumatic group, significantly on neck muscle function (cervical extension mobility p=0.005, cranio-cervical flexion test p=0.007, cervical extensor test p=0.006) and cervical pressure pain threshold bilateral (p=0.002/0.004), as well on self-reported function (Neck Disability Index p=0.001 and Patient-Specific Functional Scale p=0.007), mental quality of life (mental component summary of the Short Form Health Survey p=0.004 and EuroQol-5D p=0.001) and depression (Beck Depression Inventory-II p=0.001).

CONCLUSIONS

This study showed significant differences between chronic neck pain patients when differentiated into groups based on their onset of pain. However, no specific clinical test or self-reported characteristic could differentiate between the groups at an individual patient level.

IMPLICATIONS

Pressure pain threshold tests, cervical muscle performance tests and patient-reported characteristics about self-perceived function and psychological factors may assist in profiling chronic neck pain patients. The need for more intensive management of those with a traumatic onset compared with those with a non-traumatic onset should be examined further.

Predicting nonrecovery among whiplash patients in the emergency room and in an insurance company setting

PURPOSE

To construct and validate a prediction instrument for early identification of patients with a high risk of delayed recovery after whiplash injuries (PPS-WAD) in an insurance company setting.

METHODS

Prospective cohort study. On the basis of a historic cohort (n = 130) of patients with a whiplash injury identified in an emergency room (ER, model-building set), we used logistic regression to construct an instrument consisting of two demographic variables (i.e. questions of educational level and work status) and the patient-rated physical and mental status during the acute phase to predict self-reported nonrecovery after 6 months. We evaluated the instrument's ability to predict nonrecovery in a new cohort (n = 204) of patients originating from an insurance company setting (IC, validation set).

RESULTS

The prediction instrument had low reproducibility when the setting was changed from the ER cohort to the IC cohort. The overall percentage of correct predictions of nonrecovery in the ER cohort was 78 % compared with 62 % in the IC cohort. The sensitivity and specificity in relation to nonrecovery were both 78 % in the ER cohort. The sensitivity and specificity in the insurance company setting was lower, 67 and 50 %.

CONCLUSION

Clinical decision rules need validation before they are used in a new setting. An instrument consisting of four questions with an excellent possibility of identifying patients with a high risk of nonrecovery after a whiplash injury in the emergency room was not as useful in an insurance company setting. The importance and type of the risk factors for not recovering probably differ between the settings, as well as the individuals.

Impact characteristics of a vehicle population in low speed front to rear collisions

Rear impact collisions are mostly low severity, but carry a very high societal cost due to reported symptoms of whiplash and related soft tissue injuries. Given the difficulty in physiological measurement of damage in whiplash patients, there is a significant need to assess rear impact severity on the basis of vehicle damage. This paper presents fundamental impact equations on the basis of an equivalent single vehicle to rigid barrier collision in order to predict relationships between impact speed, maximum dynamic crush, mean and peak acceleration, time to common velocity and vehicle stiffness. These are then applied in regression analysis of published staged low speed rear impact tests. The equivalent mean and peak accelerations are linear functions of the collision closing speed, while the time to common velocity is independent of the collision closing speed. Furthermore, the time to common velocity can be used as a surrogate measure of the normalized vehicle stiffness, which provides opportunity for future accident reconstruction.