The diagnosis of degenerative cervical myelopathy (DCM) can be tricky to diagnose but gait assessment offers opportunity to pick it up early. But which gait assessment tool is best?
DCM is a common neurological disorder with an estimated prevalence of 1.6 in every 100,000 people over the age of 65. Because of the way the condition affects the spinal cord in the neck symptoms can be very varied.
This means it is a tricky disorder to diagnose in the early stages as a careful history and examination are required with suspicions corroborated with radiological findings. It’s often down to clinician experience as to who is caught early and referred for cervical decompression soon enough to prevent severe permanent damage taking place.
Reduced walking ability is one of the early signs of the condition and offers clinicians an early opportunity to consider the condition in their differentials. Gait assessment also enables clinicians to track rate of progression of symptoms and just urgency of onward referral. The challenge is it is unclear which gait assessment tool is most reliable and valid for assessing DCM.
A new systematic review published in The Journal of Spinal Surgery set out with the aim of reviewing the literature of identify the measurement properties of all existing gait assessment tools for DCM to tell us which is most reliable and valid and therefore which we should be using in practice.
This systematic review was prospectively registered in PROSPERO and adhered to the PRISMA guidance throughout. Studies were included within the review if they met the following criteria:
- Were RCTs and observational studies published in English
- Included participants who were 40 years or older with a diagnosis of DCM
- Used outcome measures that assessed at least on property of walking
For the purposes of this review DCM was defined as compression of the spinal cord at the level of the cervical spine caused by degenerative changes.
The search strategy was developed using previous systematic reviews on the topic and used a simple keyword search approach tailored to the database being used. The strategy isn’t available in full which limited the ability to evaluate the methodology.
Any disagreements about inclusion were resolved by consensus with a third reviewer being available if consensus was not reached. Methodological quality of included studies was assessed using the COSMIN risk of bias checklist.
After duplicate removal and screening a total of 20 studies were included within the review with 12 difference gait assessments being used. The most commonly used were the JOA (n=4) with a total of 253 participants and the mJOA (n=4) with a total of 547 participants.
The other most commonly used tools were the 30-metre walk test (n=3) with 743 participants, the 10-second step test (n=2) with 1, 468 participants and the Nurick scale (n=2) with 2, 380 participants).
According to the COSMIN risk of bias tool five studies were rated as very good, seven as adequate, three as doubtful and five as inadequate. The studies which were rated as very good used the 30-metre walk test, 10-second step test, mJOA and the JOACMEQ.
Construct validity examines the question – does the measure behave like the theory says a measure of that construct should behave? In essence does the outcome measure assess what it should measure.
The findings of this systematic review suggest that the Nurick grade, 30-metre walk test and mJOA all have high levels of construct validity compared to the other measures used within the systematic review.
In terms of reliability the JOA and mJOA were both found have sufficient levels of inter-rater reliability as well as test-retest reliability. The 10-second step test, 30-metre walk test and foot tap test all also have acceptable levels of inter-rater reliability.
When looked at in terms of both validity and reliability this study recommends a combination of mJOA and 30MWT are used in clinical practice.