Compression of the cervical spinal cord by a centrally herniated cervical disc: a case report

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Compression of the cervical spinal cord by a centrally herniated cervical disc: a case report

ABSTRACT. A case of spinal cord compression by means of a centrally herniated cervical disc is described. Central disc herniations often result in gait disturbances, disequilibrium, paresthesias, vibratory sense deficits, long tract signs, and occasionally decreased appreciation of pain and temperature. In most cases, however, little to no cervical spine pain is exhibited. Currently, the incidence of the finding of full and painless cervical range of motion and its relationship with central cervical disc herniations is not well described in the literature. Clinical differentiation between central herniations and degenerative spinal cord diseases is often difficult. The importance of a routine neurological examination to determine a patient's initial neurological status is emphasized.

KEY WORDS: (MeSH) Cervical vertebrae and intervertebral disk displacement -- Chiropractic -- Spinal cord; (Non-MeSH) Cervical disc herniation -- Spinal cord compression -- Chiropractic -- Cervical intervertebral disc

COMPRESSION OF THE CERVICAL SPINAL CORD and/or compression of the nerve roots are recognized as possible complications of cervical disc herniations [ 1-7]. The diagnosis of a cervical disc herniation is suspected on the basis of history, as well as the clinical findings observed in the orthopedic and neurologic examination. The diagnosis is usually then confirmed by special imaging studies such as magnetic resonance imaging (MRI), computerized tomography (CT), and sometimes myelography.

The majority of patients presenting with cervical disc herniations respond well to conservative care. However, patients that demonstrate long track signs or progressive motor weakness (hard neurological signs) tend to respond less favorably to conservative care. Therefore, most patients with cervical disc herniations that present without hard neurological signs deserve a trial of conservative care before a neurosurgical consultation is considered [ 1].

The chiropractor is well suited to diagnose and manage such cases. However, prior to the administration of any treatment, a patient's initial neurological status must be clearly established. Establishing neurologic status will enable the clinician to monitor the patient throughout the course of treatment and will also provide the clinician with a baseline for determining if a patient is responding to care, or if their condition is progressive in nature. Patients that do exhibit progressive neurological deficits should be immediately referred for a neurological consultation.

A report of a patient with a central cervical disc herniation is described. The presentation of this particular patient was complicated by the presence of hard neurological signs. It was determined that conservative management was inappropriate; therefore, a neurosurgical consultation was sought, and decompressive surgery was performed.

CASE REPORT

A 39-year-old male hardware supervisor presented complaining of intermittent numbness and tingling in the fingertips of his second through fifth digits bilaterally. Although currently employed in a supervisory capacity, he revealed a long history that involved a great deal of heavy lifting. He reported that his symptoms first appeared approximately 2 months prior to presentation after diving into a river while on vacation. The patient denied ever hitting his head on the bottom of the river.

The numbness and tingling was not constant, although it could be provoked by actively hyperextending the cervical spine. It was revealed that active hyperextension would also occasionally reproduce similar symptoms in the lateral aspects of both upper extremities. He also reported that recently he had been experiencing symptoms in both lower extremities as well. These symptoms were described as a "heavy feeling" and he revealed that this caused him to "bump into things" quite frequently. Upon further questioning, it was revealed that he had also experienced disturbances in his vision that were "difficult to describe." The patient related no disturbance in sphincter tone as it related to his bowel or bladder function. Also, he had consulted no other health care practitioner regarding these complaints prior to seeking chiropractic care.

Examination revealed a healthy, well-nourished adult male who was in no acute distress. His gait appeared staggered and slightly sluggish. Palpation revealed only slight tenderness and increased muscular tonus within the lower cervical paraspinal muscles. Both cervical and dorsolumbar active ranges of motion were accomplished fully and without pain. However, active cervical extension with passive over pressure reproduced the tingling in the patient's fingertips bilaterally, as did the performance of the cervical compression test. The remainder of the orthopedic examination, including Valsalva's maneuver, was essentially unremarkable.

Neurologically, the patient exhibited marked unsteadiness during the performance of tandem gait and Rhomberg's test. Brisk lower extremity deep tendon reflexes, graded +4/+5 using the Wexler Scale, were elicited bilaterally (Table 1). Bilateral Babinski and Hoffmann signs were markedly evident as well. Sensory appreciation to light touch was found to be increased over the C5, C6, and C7 dermatomal distributions bilaterally. Upper and lower extremity motor strengths appeared to be well maintained bilaterally.

In view of the patient's presenting neurological status, plain film radiographs were not obtained. Instead, the patient was immediately referred for a neurological consultation. Although the patient exhibited some outward signs that were consistent with a mechanical condition, initially it was thought that this patient was suffering from an organic disorder. The differential diagnosis included multiple sclerosis, amyotrophic lateral sclerosis, a compressive spinal cord space occupying lesion (neoplasm), or post-traumatic cervical spinal cord injury.

The consulting neurologist concurred with the examination findings and the initial impressions. Immediately following the neurological consultation, the patient was referred for special imaging. Subsequently, a MRI of the cervical spine was obtained. Interpretation of the MRI scan revealed two large central disc herniations. The first was a soft disc herniation at the C5-C6 level (Figs. 1 and 2). This herniation was central and left pericentral, and was encroaching on both nerve roots as well as compressing the spinal cord to 50% of its normal diameter. The second herniation was at the C6-C7 level, where disc space narrowing and osteophyte formation was present (Figs. 1 and 3). This was a hard or bony disc herniation, and its location was central and right pericentral. The hard herniation compressed both nerve roots and the spinal cord at the C6-C7 level. However, the extent of compression was less than that observed at the C5-C6 level.

The MRI findings confirmed the diagnosis, and emergency decompressive surgery was performed that same evening. The surgeon opted to perform a procedure which was approached from the posterior. The operative procedure consisted of bilateral decompressive laminectomies and foraminotomies at the C5, C6, and C7 levels. Additionally, a total discectomy of the C5-C6 disc was performed to decompress the cord at that level.

DISCUSSION

A case of cervical spinal cord compression by means of a centrally herniated cervical disc is presented. According to previous studies, the signs and symptoms illustrated in this case are not uncommon [ 2-7]. Central herniations frequently compress the corticospinal tracts, posterior columns, and occasionally the spinothalamic tracts, which gives rise to such symptoms as gait disturbances (often the principal complaint), disequilibrium, paresthesias, vibratory sense deficits, decreased appreciation of pain and temperature, and long tract signs (spasticity, hyperreflexia, and elicitation of Babinski and Hoffmann signs) (fig. 4). Lower extremity symptoms are generally more predominant than upper extremity symptoms [ 2-4]. Other less frequently observed symptoms include low back pain, a complete or incomplete Brown-Sequard Syndrome, and sphincter disturbances, resulting in bowel or bladder dysfunction [ 2-4]. Actively hyperextending the cervical spine will aggravate the radicular symptoms in most cases [ 1, 5-10]. This is due to the change in spinal anatomy that takes place when the spine is in an extended position (fig. 5) [ 8-10]. Surprisingly, cervical spine pain is one symptom that is not frequently observed in these cases [ 3]. Also, the incidence of the finding of full and painless cervical range of motion and its association with central disc herniations is not well described in the literature.

Lateral disc herniations demonstrate a completely different clinical picture. Symptoms of nerve root compression predominate, and the more frequently observed clinical manifestations include localized suboccipital or cervical pain, shoulder or arm pain, which is radicular in nature, diminished cervical range of motion with accompanying pain, upper extremity hyporeflexia, upper extremity motor weakness, paresthesias that follow a dermatomal distribution, elicitation of pain during performance of cervical compression and/or Valsalva's maneuver, and finally, diminution of pain upon abduction of the effected extremity [ 1, 7, 11-14]. Chronic lateral herniations can progress to involve the spinal cord, but this occurs in only a small percentage of cases [ 1, 11, 14]. Differentiation between central and lateral disc herniations can be easily accomplished on the basis of the clinical and special imaging findings.

It has been suggested that differentiation between central cervical disc herniations and degenerative spinal cord diseases such as multiple sclerosis, primary lateral sclerosis, or amyotrophic lateral sclerosis is often very difficult [ 2-6]. Cranial nerve involvement is often the only symptom differentiating these two conditions [ 3, 4]. However, not all patients with degenerative spinal cord diseases exhibit cranial nerve abnormalities. This complicates the diagnostic process and exemplifies the need for special imaging to confirm a suspected diagnosis.

Special imaging procedures contribute the majority of diagnostic information needed to confirm a diagnosis. MRI, CT, and myelography studies are all useful in confirming a suspected diagnosis of cervical disc herniation. MRI is considered to be the study of choice when minimal osteoarthritic change is present [ 1]; while CT is considered to be the study of choice when more extensive bony changes exist [ 5].

In the majority of instances, plain film radiography yields little diagnostic information to cases of cervical soft disc herniations [ 2-4, 7]. In some cases, however, osteoarthritic changes such as osteophyte formation and disc space narrowing are evident at the level of the herniation. However, poor correlation exists between the presence of these radiographic findings and the patient's clinical symptomatology [ 7]. Only when advanced degenerative change is present can a correlation be made between patient symptoms and these radiographic findings [ 5, 6, 8]. In these instances, the herniations are usually hard or bony rather than soft.

Although it seems trauma should be an important causative factor in the etiology of herniated cervical discs, this is not always the case. In cases of central disc berniations especially, the onset of symptoms is sometimes insidious, and the etiology cannot always be attributed to a specific traumatic event [ 3, 4, 7]. Fortunately, most cervical disc herniations have a traumatic onset that can be related by the patient at the time of the history, making the diagnostic process a much easier one [ 3, 4, 7, 11, 12, 15-17]. Epidemiologically, there is evidence that suggests which cervical disc herniations are more prevalent in males [ 3, 4, 11, 12]. These studies observed that approximately 65% of the cervical disc patients were males and approximately 35% were females [ 3, 4, 11, 12]. The rationale for this finding is due to the fact that males typically perform more physically demanding job tasks, which place them at a higher risk for developing cervical disc herniations. These findings were contrasted by other studies, which suggest the exact opposite conclusions [ 1, 2]. In these studies, approximately 75% of the patients suffering from cervical disc herniations were female and 25% were male [ 1, 2]. These studies suggested no rationale for their findings. The age range of those found to have herniated cervical discs were consistently between the ages of 30 and 60 years [ 1-4, 11, 12]. By far the most frequently herniated level was C5-C6 (55%), followed by C6-C7 (25%) and then C4-C5 (10%) [ 1-4, 7, 11, 12, 15].

CONCLUSION

In review, central cervical disc herniations frequently present with subjective complaints involving gait, equilibrium, and/or paresthesias. Cervical spine pain is rarely among these complaints [ 3]. This condition is frequently confused with degenerative spinal cord diseases. The presence of cranial nerve abnormalities is the key to distinguishing the two conditions.

Neurologically, this case presented classically for a central cervical disc herniation. The subjective visual disturbance related in the history was the only exception in this case. Therefore, special imaging and eventually decompressive surgery was necessary to confirm the suspected diagnosis.

Current literature does not correlate the finding of full and painless cervical range of motion with central cervical disc herniations. Because range of motion is frequently used as a major criteria for distinguishing mechanical conditions from nonmechanical conditions, it is essential that the clinician be aware central herniations may demonstrate no abnormalities during the range of motion examination. Further investigation is needed to determine if this is an isolated case or whether this finding is more prevalent than the literature suggests.

Finally, this case exemplifies the importance of performing thorough initial examinations. While this patient presented with vague subjective complaints and demonstrated no signs of acute distress, his neurological status was found to be severely disturbed. The only method for detecting such disturbances is by means of thorough examinations. Such examinations should always be performed prior to administering any manipulative procedures.

Acknowledgment

I wish to acknowledge two individuals. First, Dr. Eugene F. Siekerka, without his support this manuscript would not be possible. Also, Dr. Nell C. Stern for his helpful suggestions upon editing the preliminary manuscript, as well as his photographic expertise.
References

[1.] Eliyahu DJB. Disc herniations of the cervical spine. Am J Chiro Med 1989;2:93-100

[2.] Vassilouthis J, Kalovithouris A, Papandreou A, Tegos S. The symptomatic incompetent cervical intervertebral disc. Neurosurgery 1989;25:232-9

[3.] Bucy PC, Heimburger RF, Oberhill HR. Compression of the cervical spinal cord by herniated intervertebral discs. J Neurosurg 1948;5:471-92

[4.] Yuhl ET, Hanna D, Rasmussen T, Richter RB: Diagnosis and surgical therapy of chronic midline cervical disc protrusions. Neurology 1955;5:494-509

[5.] Burns SH, Mior SA, O'Connor SM. Cervical spondylotic myelopathy: part I: anatomical and pathomechanical considerations, part II: clinical and imaging considerations. J Can Chiro Assoc 1991;35:75-88

[6.] Clark CR. Cervical spondylotic myelopathy: History and physical findings. Spine 1988;13:847-9

[7.] Rothman RH, Marvel JP. The acute cervical disc. Clin Orthop 1975;109:59-68

[8.] Parke WW. Correlative anatomy of cervical spondylotic myelopathy. Spine 1988;13:831-7

[9.] Breig A. Biomechanics of the central nervous system. Stockholm: Almqvist & Wiksell, 1960: 22-80

[10.] Finneson B. Low back pain. 2nd ed. Philadelphia: J.B. Lippincott Co., 1980: 432

[11.] Yoss RE, Corbin KB, MacCarty CS, Love JG. Significance of symptoms and signs in localization of involved root in cervical disc protrusion. Neurology 1957;7:673-83

[12.] Beatty RM, Fowler FD, Hanson EJ. The abducted arm as a sign of ruptured cervical disc. Neurosurgery 1987;21:731-2

[13.] Critides SD. Abducted arm showing cervical disc herniation. Neurosurgery 1988;22:1115

[14.] Cailliet R: Neck and arm pain. Philadelphia: FA Davis Company, 1964: 45-9

[15.] Roda JM, Gonzalez C, Blazquez MG, Alvarez MP, Arguello C. Intradural herniated cervical disc. J Neurosurg 1982;57:278-80

[16.] Lee S, Cheng S, Lui T. Intradural rupture of cervical intervertebral disc. Spine 1989;14:1412-4

[17.] Parnell AP. Cervical intradural disc protrusion. J Neurol Neurosurg Psychiatry, 1988;51:1007

The National College of Chiropractic.

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By Jack R. Siekerka

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