Terminology

This is a significant chapter, as degenerative diseases of the spine are a socio-economic issue, either in young or in aged population. The incidence of these diseases is growing. Aged people do not tolerate any longer to be "invalidated" by spinal back pain. Most of these diseases are of orthopedic or physiatric interest. The following is a series of diseases of neurosurgical interest, although "overtreatment" is around the corner.
Clinically, they present with irradiated pain, neurological deficit in the territory of the involved nerve, paraparesis or tetraparesis if the cord is compressed.
Diagnosis is made on CT Scan and MRI. Dynamic plain radiographs should always be done to exclude spine instability.
This condition is due to ligamentous hypertrophy, associated with arthrosis and cervical disc rigidity. The result is narrowing of the space for the spinal cord in the canal, as well as of the space for the nerves in the foramina. Cervical stenosis may be very disabling, as it causes severe pain and neurological deficit of the upper and lower limbs, with spasticity that may become severe.
Posterior laminectomy with or without stabilization is the therapy of choice for symptomatic cervical stenosis. Sometimes, an anterior approach (as in the case of cervical disc disease) may be more indicated.

It is the same disease at the lumbar level and a little more frequent. As in the case of cervical stenosis, it is prevalent in the aged population.
At the lumbar level, there is no more cord. The compression is on the spinal roots that get out from the spine to form the femoral and sciatic nerves. Patients with spinal lumbar stenosis typically have pain while walking. The pain improves while sitting or laying down. The pain may be severe and disabling, as the patient can walk only for few minutes.
In obese patients, the first therapy is diet.
Neurosurgery has the same role as for cervical stenosis. With correct indication, posterior laminectomy with or without internal stabilization gives quite good results in terms of quality of life.
A herniated cervical disc may cause spinal cord and spinal root compression. Thus, the symptoms may be severe: pain to an upper limb, neurological deficit related to the affected root/roots, paraparesis and spasticity if the cord is compressed (Fig. 8.3). Neurosurgery is useful, if conservative therapies have failed, and mandatory in cases with severe and/or progressive neurological deterioration. Manipulations are contraindicated in cases of herniated disc.
Herniated cervical disc surgery is performed from the anterior route in the neck, with the operating microscope. It is an elegant and refined operation. The disc is removed and replaced with an articulated prosthesis (arthroplasty), in younger patients to preserve the mobility of the affected segment, or with a fixed prosthesis (arthrodesis).
This is a very rare condition. The patient with a herniated thoracic disc generally presents with spinal cord compression. In these cases, neurosurgery is necessary. There are several approaches. We feel that the transpleural approach is too much for this disease. We use the extrapleural, partial costotrasversectomy to access a thoracic herniated disc.
Herniated Lumbar Discs are the most frequent. Those at L4-L5 and L5-S1 present with sciatica, i.e. pain irradiating along the posterior part of the thigh and leg. The more cranial ones present with cruralgia, i.e. pain irradiating along the anterior surface of the thigh down to the knee. Severe motor deficit may follow and/or coexist with pain.
Diagnosis is made on the basis of MRI and CT Scan images. Obesity is a bad prognostic factor. If symptoms persist for several weeks, microneurosurgical removal is the therapy of choice. If the indication for neurosurgery is correct, results are quite good.