Nerve Root Compression

We prospectively evaluated the association between the diagnosis of LSS and clinical information, including the history and physical examination of patients with leg symptoms. This study was performed in six university hospitals, ten medical centers, and sixty eight hospitals and clinics affiliated with university hospitals or medical centers during July and September in 2004. We enrolled consecutive patients older than 20 years of age with primary symptoms of pain or numbness in the legs. We excluded patients who have been treated by some medical practices within one year before examination. Patients with cervical myelopathy, previous surgery, degenerative scoliosis (defined as lateral tilting of more than 10 degrees) and inflammatory disorders were also excluded. This study included 250 patients who complained of leg symptoms, including cases of LSS (n = 165), lumbar disc herniation (n = 61), diabetic neuropathy (n = 13), and peripheral vascular disease (n = 11) (Table 3). The study was approved by the institutional review board of each study institution as necessary. Written informed consent was obtained from the all patients. The patients gave informed consent and then answered the SSHQ. The following steps were taken to reach a final diagnosis for each of the enrolled patients (Figure 1). In the first step, at each institution the orthopedic physician who saw a patient made the clinical diagnosis based on the history, physical examination, and radiographic findings. In addition, to verify the diagnosis made by each physician, six board-certified spine surgeons approved by the Japanese Board of Spine Surgery also made a diagnosis for each patient based on the clinical information and findings of the MRI. The opinions of six board-certified spine surgeons approved by the Japanese Board of Spine Surgery were used as the gold standard for diagnosis of LSS. The radicular type was characterized by symptoms of pain, burning, numbness, and paresthesias following a specific dermatome with radiological evidence of the responsible nerve root compression, which was confirmed if intermittent claudication was abolished following single nerve root infiltration. Patients of the cauda equina type presented some bilateral symptoms related to cauda equina compression syndrome with less dermatomal-specific neurogenic claudication and radiological evidence of cauda equina compression.
The sensitivity, specificity, likelihood ratio, and area under the receiver operating characteristic (ROC) curve were estimated. 217 patients classified by investigators as suffering from lower back pain without a significant change in symptoms were given the SSHQ two weeks later during an outpatient visit, and the test-retest reliability over two weeks was investigated in these patients.

The outcome of interest in this study was a diagnosis of sciatica. Two reference standards were chosen for the diagnostic model:
Model (i): High confidence (≥ 80%) sciatica clinical diagnosis
Diagnosis of sciatica for model (i) reference standard was when the clinician documented the presence of leg pain was due to sciatica and they were ≥ 80% confident in their diagnosis. A cut off point of ≥ 80% diagnostic confidence was used because at this criterion, reliability among clinicians diagnosing LBLP improves considerably [4 (link)].
Model (ii): High confidence (≥ 80%) sciatica clinical diagnosis with confirmatory MRI findings
The second reference standard combined the clinician’s diagnosis with MRI findings (possible/definite) of nerve root compression. Using clinical diagnosis alone as a reference standard may leave diagnosis open to incorporation bias as the reference standard is not blind to knowledge of the predictors under consideration [25 ].

Two-hundred and two participants were consecutively recruited at four neurosurgery/neuro-orthopaedic clinics in Sweden between 2009 and 2012^{12 (link),13 (link)}, of which 201 underwent surgery (mean age 50; SD 8.4 years, 52% men, neck pain median duration 14 months; arm pain median duration 12 months; IQR 16). The inclusion criteria were: age 18–70 years, persistent radiculopathy symptoms for at least two months, clinical findings of nerve root compression based on examination by a neurosurgeon/neuro-orthopaedic surgeon and compatible with verified cervical disc disease determined by magnetic resonance imaging, and undergoing surgery for CR by either anterior approach (ACDF) or posterior approach with foraminotomy/laminectomy at one to three segmental levels. The exclusion criteria were: myelopathy, previous fracture or luxation of the cervical column, malignancy or spinal tumour, spinal infection, previous surgery in the cervical column, systematic disease or trauma that contraindicated either the rehabilitation programme or the measurements, diagnosis of a severe psychiatric disorder (such as schizophrenia or psychosis), known drug abuse and lack of familiarity with the Swedish language (unable to understand and answer the questionnaires). Of the 201 participants who underwent surgery, 163 were operated on with ACDF using standard cages (i.e. filled with bone substitute or autologous bone collected during decompression; no iliac crest graft was taken) at the clinic where the participant was included. In most cases of multilevel surgery, an anterior plate was added to achieve primary stability. Thirty-eight patients underwent posterior foraminotomy, with or without laminectomy (without fusion). Eight participants did not fulfil the clinical neurological examination at baseline and were excluded from this secondary analysis of outcomes. Thus, the present cohort consisted of 193 participants (Table 1). A total of 153 (79% response rate) and 135 (70% response rate) participants completed the clinical examination at one- and two-year follow-up (Fig. 1). Of the participants attending one-year follow-up, 83 (46%) were men and mean age was 50 (SD 8.2). At the two-year follow-up, 72 (53%) were men and mean age was 50 (SD 8.3). There was no difference in background variables or preoperative neurological outcomes between the patients who attended the neurological clinical examination at follow-up and those who were lost to follow-up (p > 0.194). Patients attending clinical examination at follow-up scored NDI mean value 21 (SD 16.7) at one-year follow-up, and 23 (SD 18.3) at two-year follow-up. There was also no difference in background variables or neurological outcomes at baseline between participants randomized to SPT or SA (p > 0.08) (Table 1).Table 1

Background variables for participants with cervical radiculopathy who underwent surgery and postoperative rehabilitation and were included in the secondary analysis of postoperative neurological outcomes.

	N	Total	SPT (N = 97)	SA (N = 96)
Age, mean (SD)	193	50 (8.4)	50 (8.3)	50 (8.6)
Sex male, n (%)	193	100 (52)	48 (50)	52 (54)
Anterior surgery, n (%)	193	155 (80)	73 (75)	82 (85)
NDI %, mean (SD)	184	43 (14.9)	42 (14.5)	44 (15.4)
Neck pain mm VAS, mean (SD)	188	56 (24.3)	55 (24.9)	57 (23.8)
Arm pain mm VAS, mean (SD)	185	50 (28.0)	52 (26.5)	48 (29.5)
Neurological impairment prick touch, n (%)	193	154 (80)	78 (80)	76 (80)
Neurological impairment light touch, n (%)	193	138 (72)	70 (72)	68 (71)
Neurological impairment motor function, n (%)	191	150 (79)	80 (83)	70 (74)
Neurological impairment arm reflex, n (%)	186	109 (59)	50 (53)	59 (64)
Positive Spurling test, n (%)	142	91 (64)	49 (67)	42 (61)

Results are presented with mean value and standard deviation (SD) or number (n) and percentage (%).

Figure 1

Flow chart of participants included in the analyses of secondary neurological outcomes.

Mice were anesthetized with isoflurane inhalation. Surgery was performed under an Omano surgical microscope (OM2300S-V7, 7-40X). A 1–1.5 cm midline neck incision was used. The superficial tissues were bluntly dissected and lateralized with a mini retractor. The neck muscles were gently dissected to locate the mouse’s right auditory bulla and the auditory capsule on the right side of the head, which are the landmarks to locate the foramen lacerum. A prepared piece of Surgifoam (Ethicon) at approximately 1–1.5 mg was gently delivered into the foramen lacerum using curved forceps. The Surgifoam was positioned between the trigeminal nerve root and the cochlea bulla. After removing the retractor and replacing the tissues, the skin was closed with 6-0 nylon monofilament (Ethicon) sutures. Mice in the sham group underwent the same surgical procedure including neck shaving, skin incision, muscle dissection, and foramen lacerum exposure without nerve root compression. The duration of the surgery ranged from 8 to 12 minutes per mouse. Tamoxifen was intraperitoneally administrated to Fos-iCre-ERT2 (Fos^2A-iCreER-knockin) mice immediately after the FLIT procedure.

A total of 54 participants were included in the study. The subjects should be between 18 and 60 years and agree to the design of the study, voluntarily participating in it and signing the informed consent. The sample was divided into two groups: case group (n = 23 subjects with NS-LBP) and control group (n = 31 subjects without NS-LBP). For inclusion in the case group, the characteristics of the NS-LBP must be: (1) low back pain located in the region between T12-L1 to L5, (2) unilateral or bilateral distribution within this region, (3) not irradiated to other regions, (4) not necessarily being continuous, and (5) an evolution of more than three months. For the control group, healthy subjects without NS-LBP at least during the previous three months or at present were included.
Exclusion criteria for both groups comprised the presence of congenital musculoskeletal disorders, spinal deformities, compression of nerve roots, oncological processes, or any other process that may be the cause of NS-LBP. The presence of NS-LBP that does not meet the characteristics described for inclusion were also considered as exclusion criteria. In addition, participants with body mass index (BMI) higher than 31 Kg/m² and diagnoses of respiratory or neurological conditions were excluded.