Tandem spinal stenosis
Tandem spinal stenosis is estimated to be present in 5-25% of patients with stenosis, and occurs when multiple spinal compressions exist at the same time.
Due to the severity of one compression, additional compressions may not be noted initially. This case study illustrates an example of a post-decompression Cervical Myelopathy, in which a lower level of Cauda Equina Syndrome was also discovered.
Cervical Myelopathy is a stenotic compression of the spinal cord at the cervical level, and often results in coordination and gait disturbances, as well as upper extremity impairments. Upper motor neuron signs are present with spinal cord compressions and tests such as Babinski, Hoffman’s, and L’hermitte’s Sign are positive.
Cauda Equine Syndrome is the compression of the distal ends of the spinal cord, due to lumbar spinal stenosis. It presents clinically as severe lower extremity motor and sensory changes including bowel and bladder dysfunctions. Both cervical myelopathy and cauda equine syndrome can become emergent, if compression becomes severe enough.
This article discusses tandem spinal stenosis - when more than one level of the spinal cord is compressed at a time. In this specific case, the patient was a 71-year-old male who had recently undergone a Cervical Myelopathy decompression by spinal fusion.
The patient was receiving physiotherapy post-operatively, and was still presenting with some neurological impairments, which can be typical following decompression. Early treatment consisted of cervical active range of motion exercises to address impaired mobility, stabilization training as well as endurance training of the cervical spine due to deficits related to continued pain and disability following cervical fusion surgery.
However, 8 weeks post-operatively the patient was noting bilateral pain in the lower extremities. This presentation progressed over the following couple of weeks to bowel and bladder incontinence and difficulty with climbing stairs.
The patient was then sent to the emergency department, underwent another MRI and this revealed multi-level compressions in the lumbar spine, with critical stenosis at L4-L5. The patient underwent lumbar decompressive laminectomy and foraminotomy bilaterally at T12-L1, L1-2, and L4-5 approximately 2 weeks later.
This case study highlights the need for clinicians to be hypervigilant of testing and neurological examinations - even after a patient has undergone a spinal decompression.
Tandem Spinal Stenosis also raises further safety concerns for treatment as noted by the author: “This recognition of tandem stenosis is of particular importance to the manipulative practitioner, and should be considered in older individuals with symptoms of lumbar stenosis or gait deviations prior to the application of manipulative forces.”
For functional testing, this article also notes using a variety of movements such as cycling vs. walking vs. stairs-climbing to note if functional deficits are present at different degrees of lumbar flexion, and to note the differences between vascular claudication and spinal stenosis findings.
Even when the diagnosis post-operatively appears very straightforward, detailed attention to functional changes is critical so that emergency situations are not missed.
> From: Swanson, J Man Manip Ther 20 (2017) 50-56. All rights reserved to W.S. Maney & Son Ltd. Click here for the online summary.