While cervical spondylosis is common, here is a relatively specific and easily misdiagnosed type.
Cervical Spondylotic Amyotrophy, CSA
I. Concept: It refers to a special type of cervical spondylosis with no sensory impairment but only muscle weakness or myasthenia gravis
1, Keegan first described in 1965, Dissociated motor loss, thought to be a bone spur coincidentally compressing the anterior cervical nerve root (motor root, posterior root for sensory root)
2, known as Keegan cervical spondylosis
Second, the typing.
1, according to the muscle atrophy site typing
Proximal: muscles close to the neck (scapular girdle, deltoid, biceps, triceps)
Distal: distal from the neck to the elbow joint, forearm muscle groups, intrinsic hand muscles.
2. Keegan’s typing according to the anatomical site of compression.
Type I: only cervical nerve root compression with muscle atrophy.
Type II: both muscle atrophy and spinal cord compression (upper motor neuron symptoms, pyramidal fasciculus sign).
III. Clinical features.
1, more men than women, middle-aged and elderly, slow, few acute attacks.
2, scapular girdle muscle (posterior shoulder) atrophy is common, a few involving the intrinsic hand muscles unilateral muscle atrophy, a few bilateral no sensory impairment.
3.Most of them do not have pathological reflexes (compression of spinal cord, cone bundle sign Hoffman sign, Babinski sign).
Fourth, the clinical information of muscle atrophy manifestations.
1, scapular band muscle atrophy performance
2, intrinsic hand muscle atrophy performance (interosseous muscle)
V. Auxiliary examinations
1.MRI
Figure A: Mild limited compression of the anterior horn of the spinal cord, with high signal shadow in the spinal cord
Figure B: Mild limited compression of nerve roots
2.Electromyography suggests the presence of neurogenic damage to the muscle.
VI. Important differential diagnosis
Differentiation from lateral sclerosis of the spinal cord is the disease of the famous astronomer, Professor Stephen Hawking, who wrote “A Brief History of Time”.
1, the characteristics of spinal cord lateral sclerosis.
(1) Invasion of the brainstem and spinal cord motor neurons.
(2) Progressive, no sensory impairment.
(3) Early damage to the lower motor neurons of the spinal cord: muscle atrophy and weakness, fibrillation of the muscle bundles.
(4) Late upper motor neuron damage in the spinal cord: muscle tone advanced vertebral fasciculus sign.
(5) Usually accompanied by cranial nerve dysfunction: dysarthria, tongue muscle atrophy, swallowing disorder (key differentiation point).
2. Key distinguishing points
VII. Treatment.
1.Conservative treatment.
(1) Indications.
Medical history within 3 months.
Mild muscle atrophy.
The muscle action potential is more than 30% higher than the healthy side of the compound muscle action potential CMAP wave amplitude.
(2) Methods.
The neck brace prohibited posterior extension of the neck.
Traction of the cervical spine in mild forward flexion position for 3-4h/day.
Upper limb movement exercise.
Physiotherapy.
Neurotrophic drugs.
2.Surgical treatment
Indications.
Long history of disease, conservative ineffective.
CMAP wave amplitude is less than 20% lower than the healthy side.
Especially out of the deltoid muscle, biceps also have similar phenomenon or obvious spinal symptoms.
Note the conditions that require cautious surgery: significant progression of myasthenia gravis and MR spinal cord high signal.
3.Surgical methods
(1) Preferred anterior surgery.
MR shows that the spinal cord compression comes from the front, and anterior surgery can directly remove the compression, which is more reasonable.
(2) Posterior surgery.
For multi-stage involvement, some scholars take the posterior approach to open the spinal canal molding, the rationality of which is doubtful.
VIII. Rehabilitation
Postoperative recovery tends to be slow.
Muscle strength recovery is dominant, and gradually muscle atrophy improves.
The final degree of recovery determines the degree of muscle strength recovery.
Therefore, the degree of postoperative recovery depends on the time and degree of preoperative compression, the degree of muscle atrophy, early detection, early surgical treatment is most reasonable.