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Chapter 1
Intermittent neurogenic claudication (INC) is a complex of symptoms caused by degenerative lumbar spinal stenosis (LSS). 1 The disease was first described by Van Gelderen in 1948 and Verbiest in 1950.1-4 The characteristic symptoms are leg pain (frequently both legs), which can be exacerbated with prolonged walking and standing and/or lumbar extension, and associated back pain.1-4 As in other acquired diseases, INC is usually seen in the elderly.1, 5 Severe stenosis is common in elderly spine: 30.4% in the population have a severe stenosis (average age 67.3).5 However, only 17.5% of them have typical INC symptoms.
Diagnosis and imaging techniques:
The explanation of the symptoms is often disputed: Verbiest et al stated that the narrowing of the canal (due to degenerative tissue) leads to compression of the nerves and therefore causes symptoms of nerve impairment.4 Measuring the diameter of the lumbar spinal canal was the main tool to diagnose LSS and subsequently INC. Verbiest started in the 1950s with in vivo measuring techniques.4 In the 1960s Evans described a complete cerebral spinal fluid stop, on myelography, at the lower lumbar levels in patients with intermittent neurogenic claudication.1 Imaging techniques were used, after that discovery, preoperatively to select patients for surgical treatment. First myelography was used to prove a complete spinal fluid stop and later Computer Tomography images were used. Nowadays Magnetic Resonance (MR) imaging techniques are used to select patients with INC for treatment.6 Many different grading scales (such as the Schizas scale) exist to differentiate between mild and severe lumbar spinal stenosis on MR images. Nevertheless, good prospective studies have not been performed to assess the effectiveness and quality of MR imaging techniques and stenosis grading scales.6
Surgical treatment:
Surgical treatment is considered to be the gold standard for patients with INC caused by LSS.1-4 However, the first prospective comparative study proving that surgical therapy was superior in comparison to conservative treatment was published in 2007.7, 8 The first technique that was described to widen the lumbar spinal canal was wide bony decompression (laminectomy).9 Until today this technique is widely used. However since, INC is often accompanied by back pain, and thus to postoperative back-pain, it is hypothesized that a wide decompression is a ground for potential instability. Therefore, less invasive techniques, such as laminotomy (partial removal of the lamina), were developed and implemented.10-12
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