Spinal cord hemisection syndrome refers to a clinical syndrome in which the spinal cord is damaged due to external compression and internal lesions of the spinal cord, resulting in upper motor neuron paresis of the ipsilateral limb below the plane of the lesion, loss of deep sensation, fine tactile impairment, vasodilator dysfunction, loss of pain and temperature sensation in the contralateral limb, and preservation of bilateral tactile sensation, mainly in the cervical spine. The resulting motor impairment can affect the patient’s walking, while sensory impairment makes the patient prone to injury, especially skin sensory impairment can lead to skin burns and other injuries, which can seriously affect daily life and cause the patient’s disability.
Causes
The spinal cord contains the superior conduction tracts that govern sensation in the lower extremities and trunk, and the inferior conduction tracts that govern motor function. The inferior conduction tracts in the cervical spine include the thin wedge tract, located in the posterior cord, which conducts proprioception and fine tactile sensations from the ipsilateral trunk. The lateral tracts of the spinal thalamus are located in the lateral cords, and because they cross in the spinal cord, they conduct pain and temperature sensations from the contralateral side of the body; the anterior tracts of the spinal thalamus are located in the anterior cords and partially cross up to the contralateral side, conducting coarse tactile sensations from the trunk and extremities bilaterally. The superior conduction tracts mainly include the corticospinal tracts, which travel ipsilaterally downward and innervate the motor functions of the ipsilateral trunk. Therefore, in the case of spinal cord hemisection injury, the main manifestations are impaired motor, deep sensory, and fine tactile sensation on the ipsilateral side and pain and temperature sensation on the contralateral side, while coarse tactile sensation is preserved due to partial crossover of the anterior spinal thalamic tract.
In addition, because the fibers emanating from the posterior horn cells ascend ipsilaterally for 2-3 segments before crossing over to the contralateral side through the anterior white matter to form the lateral tract of the spinal thalamus, the level of contralateral nociceptive and thermo-sensory deficits is lower than that of the damaged segments of the spinal cord.
In summary, spinal cord hemisection syndrome is a syndrome rather than a specific primary cause, and can be caused by all injuries that can cause transverse spinal cord lesions. Common causes include external compression and internal spinal cord pathology.
External compression includes herniated discs caused by spinal degeneration on one side, spinal cord injury caused by compression on one side due to spinal fracture, compression on one side of the spinal cord due to hematoma, compression on one side of the spinal cord due to intradural tumor, and stab wounds on one side of the spinal cord.
Spinal cord lesions include myelitis, spinal cord vascular dysfunction, multiple sclerosis, and early radiation myelopathy; in addition, subacute spinal cord necrosis caused by paraneoplastic syndrome can also manifest as spinal cord hemisection syndrome.
Clinical manifestations
Disease symptoms
1.Spinal cord symptoms
Loss of motor and deep sensation in the ipsilateral limb below the plane of injury, and loss of pain and warmth in the contralateral limb are its clinical characteristics.
2.Symptoms of the primary disease
If the injury is caused by a stab wound, there is a stab injury to the skin and muscles; if the injury is caused by a spinal fracture and dislocation, the symptoms appear suddenly with a history of trauma, accompanied by neck pain and restricted movement; patients with intravertebral tumors have a long course of disease, a process of clinical symptoms and gradual progression of symptoms; patients with hematoma compression have a history of hematoma formation, such as a history of recent surgery and a history of spontaneous bleeding. Patients with myelitis have a faster onset of symptoms and a history of fever, patients with spinal cord vascular dysfunction have a shorter course and a more rapid onset, patients with multiple sclerosis have a longer course, and patients with radiation myelopathy have a history of specific radiation exposure, etc.
Hazards of the disease
It can cause neurological disorders such as somatosensory-motor disorders, which can affect patients’ walking, and sensory disorders, which can easily cause injuries, especially skin sensory disorders that can lead to skin burns and other injuries, which can seriously affect daily life and cause disability of patients.
Complications
The common complications are similar to those of spinal cord injury, including deep vein thrombosis, decubitus ulcers, and urinary tract infections in the early stage; long-term bed-ridden complications, including urinary stones, lung infections, and thermoregulation, may also occur; patients with spinal cord hemisection syndrome may also suffer from psychological depression and disorders.
Diagnosis and Differentiation
Ancillary tests
A combination of available tests should be used to find the cause of spinal cord hemisection symptoms. For example, in patients with spinal injury, cervical spine X-ray, CT, MRI and, if necessary, nerve evoked potential examination of the extremities should be performed to determine the presence of spinal cord compression and edema and bleeding; these examinations can also be used to observe the condition of the spinal cord and spinal canal to differentiate from intraspinal and spinal cord tumors. If myelitis is suspected, routine and biochemical examination of cerebrospinal fluid is feasible. If vascular factors are suspected, DSA or MRA of the spinal cord vessels may be performed.
Disease diagnosis
The diagnosis of spinal cord hemisection syndrome is not difficult, but the key is the etiological diagnosis. The diagnosis of spinal cord hemisection syndrome can be made clinically from the patient’s symptoms and neurological signs. For the etiological diagnosis, it should be clarified based on other concomitant symptoms of the patient and the results of auxiliary examinations.
Differential diagnosis
Because the clinical manifestations are very typical, the focus of differential diagnosis is on the analysis of the etiology. Of course, there exist some diseases with similar symptoms in the clinic, which can be easily confused, but with careful examination and comparison of sensory and motor functions on both sides, the diagnosis of spinal hemisection syndrome can be made by history and examination.
It should be differentiated from the common specific types of cervical spinal cord injury
1.Central type cervical spinal cord injury
The lesion occurs almost exclusively in the cervical segment, and there is still sacral sensation and movement, and sensory and upper extremity muscle weakness is more important than lower extremity is its clinical characteristics.
2, anterior spinal cord syndrome
In anterior spinal cord syndrome, the front of the cervical spinal cord is severely compressed, sometimes causing occlusion of the anterior central spinal artery, resulting in quadriplegia, lower limb paralysis more than upper limb paralysis, but the lower limbs and perineum still maintain position and deep sensation, and sometimes even retain superficial sensation.
3. Posterior spinal cord syndrome
Most of the syndromes are characterized by bilateral impairment of deep sensation and fine touch in the trunk, with less impaired motor function.
4.Transverse spinal cord damage
It shows bilateral limb paralysis below the level of spinal cord lesion, sensory loss and bladder, rectal and vegetative nerve dysfunction.
Disease treatment
Treatment mainly includes both conservative and surgical treatment.
Conservative treatment
Conservative treatment is given for inflammation of the spinal cord itself, multiple sclerosis, and other intrinsic lesions, and in the absence of external compression and internal spinal cord tumors. Conservative treatment includes local stabilization with external fixation such as cervical braces and traction, and pharmacological treatment, which includes neurotrophic drugs, neuroprotective drugs, and neurodegenerative drugs. Treatment methods such as hyperbaric oxygen can also be used.
Surgical treatment
If there is external compression of the spinal cord, such as fracture dislocation, tumor in the spinal canal, disc herniation, or hematoma compression, surgery is often required to remove the compression, otherwise the spinal cord remains in a state of compression and cannot be recovered, however, the specific surgery should be performed depending on the cause of the disease. Some fracture dislocations may not be found to be compressed after examination, but there is spinal instability that causes compression of the spinal cord at the moment of injury, and this situation also requires surgery. Surgery is mainly performed to remove the compression and to perform stabilization surgery such as internal fixation of the spine.
Prognosis of the disease
The prognosis of the disease is closely related to the cause and extent of the lesion. The prognosis is poor if caused by a tumor in the spinal cord. If caused by chronic external compression, the prognosis is better if the compression is removed at an early stage; for spinal cord injury caused by fracture dislocation, it should be judged according to the extent of the injury; if caused by spinal cord inflammation, the prognosis is better after early diagnosis and treatment. If it is caused by stabbing injury, it is more difficult to recover. In short, spinal cord hemisection injury is a kind of incomplete spinal cord injury, and the prognosis is better than complete spinal cord injury.
Disease prevention
1, for people engaged in high-risk occupations (high altitude, drivers) should pay attention to avoid trauma to the neck.
2. For patients with previous cervical spine disease, regular review should be conducted to detect potential spinal cord compression early, and attention should be paid to avoid cervical trauma.
3, usually should pay attention to keep warm, reduce the chance of colds and upper respiratory tract infections, and reduce the possibility of spinal cord inflammation.
Prevention of spinal cord hemisection syndrome is difficult, and the most important thing is to achieve early diagnosis and early treatment when there are symptoms.
Patients tend to seek medical attention as soon as possible because of the presence of somatic neurological dysfunction. Two departments should be preferred for consultation, orthopedics and neurology. Orthopedic consultation is generally preferred in cases of combined trauma, stab wounds, or when there is a preexisting spinal disorder. If there is no specific medical history, neurology may be preferred. Various imaging examinations of the spine should be performed as soon as possible after admission, especially MRI of the cervical spine and even spinal angiography, to quickly clarify the cause.
If it is caused by neurological diseases, medical treatment can be given; if it is caused by fracture dislocation, stabbing injury, disc herniation, or tumor in the spinal canal, then it belongs to the orthopedic treatment, and surgery is needed if necessary. In the case of spinal cord tumors, it is the domain of neurosurgery, and surgery should be performed by neurosurgery to remove the intramedullary tumor. Since there is a close correlation between the timing of surgery and the recovery of symptoms, once detected, the compression should be removed in time to give the damaged spinal cord a recovery environment, but the recovery of nerve function does not happen overnight and requires a long process.