Cervical disc prolapse and radiculopathy
Disc prolapse is one of the commonest problems that produce neck pain , excruciating electrical shock like or deep boring pain that spreads from the shoulder region, inter scapular region and descends down the arm to the fingers sometime associated with numbness and sensory disturbances along the affected nerve root distribution (dermatome)[ Fig 1a,1b,1c ].The neck movement can aggravate the pain and hence patients develop stiff neck with a tilt. The pain is intolerable in many since it was first appreciated in a normal person or with an existing neck pain for a long time. Weakness of the muscles (motor weakness) is seen in chronic patients who have history of repeated episode of radicular pain for a long period. [ Fig 2 ].
Cervical radiculopathy can be experienced on both sides. Usually the presentation is on one side. MRI (Magnetic Resonance Imaging ) is the investigation of choice along with X-Rays for assessing additional details. The disc prolapse can be seen compressing the nerve roots at their exit from spinal canal[ Fig 3 ]. Large disc materials can also be seen compressing the spinal cord in some cases with severe canal stenosis[ Fig 4 ]. Cervical disc prolapse can occur at multiple levels as well [ Fig 5 ]. Some of them can be significantly large and can cause spinal cord compression leading to Myelopathy, where there will be different gradients of neurological deterioration in the form of weakness in upper and lower limbs and some times associated with urinary bladder and bowel dysfunction. This condition need to addressed seriously. Delayed intervention may lead to non recovery of the lost neurological functions. Surgical intervention as an emergency should be considered the choice of treatment in these situations.
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Treatment:
Though majority of the patients can be treated by medical management and physiotherapy, significant number of patients suffer some degree of pain and discomfort that affects normal life style which is not honestly accepted by the individuals. More over though pain disappears to a large extent, numbness and progressive weakness of group of muscles does exists in many due to the persistent compression of the nerves by the disc materials. Surgery in the medically refractory patients and in those where the neurological deficit increase during the medical management is mandatory. Surgical management provides early relief of pain and prevent potential neurological deficits .This helps in early return to the normal life style that includes return to work. Microsurgical techniques provide safe surgery.
Anterior cervical discectomy:
There are seven cervical vertebras .Disc prolapse occur commonly at C4/5,C5/6 and C6/7 levels. These level discs are known to get degenerated more and prolapse very commonly.
The cervical disc is approached through an anterolateral approach in the neck. Small horizontal cosmetic incision is used to reach the disc space of choice .The prolapsed disc material compressing the nerve root is removed with microsurgical technique using sophisticated instruments .Good decompression of the nerve is confirmed .The adjusant vertebrae are grafted with iliac crest bone grafts alone , titanium cages( Fig 6a1 & a2) and PEEK (Fig 6b1 & b2)are used in select patients . This interbody fusion gives a good fusion at degenerated segments. Range of movements are well preserved in these patients.( Fig 6c)
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Artificial Disc Replacement:
Recently Artificial Disc Replacements are getting popular. They are believed to take over the functions of the disc removed during surgery and reduce post operative recovery time . Since the disc functions are substituted the patients can return to the normal life style quickly. Young patients with single level soft disc prolapse are ideal candidates for disc replacement. ( Fig 7)
* Cervical Myelopathy
Spinal cord at the cervical region can be compressed slowly over a period of time due to degenerative changes that occur in an ageing spine. Degenerated hard discs, osteophytes ,hypertrophied facets and thickened ligaments can lead to cervical canal narrowing thus allowing less space for the spinal cord to move freely in the canal( fig 8) .This leads to cord compression and reduced blood supply which can lead to dysfunction of the neural cells.
Slow motor weakness of upper and lower limbs along with wasting of hand muscles, with various degree of sensory impairment will lead to difficulty in walking with severe stiffness (spasticity). These symptoms and signs slowly cripple the patient to bed. This disorder called as Cervical spondylotic myelopathy is commonly seen in elderly and in fast aging spine individuals. Involvement of all limbs with stiffness is called Spastic quadreparesis. Severely compressed spinal cord can be easily injured in trivial accidents viz: .minor slip, whiplash injuries ,dash board injuries in car etc. Complete paralysis of the limbs (Quadreplegia) is the worst result one can expect in these patients and hence the need for the importance of early diagnosis (recognition) and treatment of this potentially dangerous disorder which just grows along with the ageing spine.
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Treatment
Majority of the patients do not improve with medical management in long terms. Early decompression of the compressed spinal cord prevents progression of the neurological deterioration and improves the patients mobility in general. Surgical decompression can be done from anterior as well as posterior approach. The final aim is to give the spinal cord enough space in the spinal canal to survive. The approach and technique is usually selected by the surgeon on individual assessment of patients.
Anterior cervical cord decompression – Corpectomy
Through an anterolateral approach in the neck the vertebral bodies,osteophytes and discs are removed with microsurgical technique. The dura matter covering the spinalcord is well decompressed and the adjusant vertebral bodies are stabilized with bonegrafts, cages (Fig 9) and anterior cervical plates. This procedure directly address the compressive elements .
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Posterior cervical cord decompression – Laminoplasty
The spinal cord can be effectively decompressed through a posterior approach. The traditional technique of laminectomy is now replaced with Laminoplasty where the posterior elements spine ,lamina and the ligaments are preserved while achieving spinal cord decompression. (Fig 10)
* Spine ( fractures) and spinal cord injuries (SCI)
Spine as a whole controls our body in all the movements. Since the spinal cord is with in the spinal canal and protected by the bone (spine) , injuries that affect the spine often affect the cord as well(Fig 11a). Neurological deficits like paralysis of the limbs are devastating and require intensive management. Recovery of neurological deficit is slow and prolonged and hence require sustained medical attention and aggressive physiotherapy and rehabilitation programmes.
Spinal cord injury (SCI) that occur at the time of injury (primary) may not be reversed in majority of patients especially when the cord is injured severely. Subsequent to this primary injury there is a cascade of chemical changes occur in and around the injured spinal cord, which will further damage the cord. This is called the Secondary SCI. For example a partially paralyzed patient may worsen in the neurological status and deteriorates. This injury can be prevented by pharmacological agents and surgery. Clinical research and human trials have shown good encouragement on methylprednisolone in acute condition.
Surgical management in the form of spinal cord decompression and stabilization with instrumentation has shown good results.(Fig 11 b1,b2) The compressed spinal cord is decompressed in the canal and hence has a chance to recover in a normal environment. Spinal stabilization facilitates spinal cord decompression and early mobilization of the patient which is the key factor in the prevention of complication due to prolonged immobilsation.(Fig 11c1,c2,c3).
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fig 11 c1 |
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Stem cells are at research level at present and many clinical trials are on in many countries. Stem cell therapy may be included along with surgery and medicines in near future.
* Developmental disorders of cervical ( neck ) region
Cranio vertebral anomalies
Atlanto axial dislocation : The first cervical bone ( vertebra) C1 and the second C2 may be in misalignment and can cause neck pain and neurological symptoms in the limbs (12a). The ideal form of treatment is surgical correction and bone grafting. This procedure secure the bones in alignment and hence prevent the spinal cord from compression.
Occasionally the two vertebrae may not be reduced with cervical traction . In these situation decompression of the spinal cord and stabilization are done with special procedures. Trans oral decompression is one such procedure.( 12b,c)
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Arnold chiari malformation : In this condition a small portion of cerebellum – vermis descends down from the cranial cavity (due crowding of structures in the posterior fossa ) into the cervical spinal canal thus altering the fluid pathway. This in turn cause dilation of the central canal in the spinal cord ( syringomylia) and produce neurological symptoms.(13a)
Surgical decompression of the posterior fossa and the upper cervical bones (laminae) improves the functions and arrest the disease process. The dilatation of the canal reduces spontaneously following surgery.(13b)
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Developmental disorders of Lumbar region ( Back)
Spinal dysraphism: Menigoceles, Myelomenigocoele and Tethered cord are some of the commenest disorders seen in paediatric population. Surgical management is essential in select cases to prevent infection and progressive neurological deficit. Cosmetic reconstruction is essential. In patients with severe neurological deficit and multi system abnormalities the long term results are very much challenging and the cost of multiple surgeries until adult age is very high.
Spinal canal tumours: Intra dural extra medullary Neurofibroma and Meningiomas are commenest tumours that produce varied neurological deficits with symptoms. These tumours are usually benign and need to be excised particularly when symptomatic. Majority of them are excised totally with microsurgical technique. These tumours present various levels of the spinal canal.
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Disc is a cushion like
structure that lie between the end surface of bones
that from the spine. The disc allows movement of the
spine & acts like a shock absorber. The nerves run
close to the disc in the spinal canal. When a disc is
damaged, the soft center may slip out (prolapse) and
press on a nerve(Fig .1.)
In
majority of the cases conservative (physiotherapy
and bed rest) and medical line of treatment will
reduce the pain. However some of the patients may
not recover completely. Hence may require surgery.
Surgery is carried out to relieve persisting pain
and to arrest further neurological deficit. Advanced
spinal surgical procedure like micro lumbar discectomy
and micro endoscopic discectomy are offered to the
patient. Both these techniques are keyhole procedures
performed through a small incision on the back
