Surgical anatomic evaluation of the cervical pedicle and adjacent neural structures

OBJECTIVE

Although several clinical applications of transpedicular screw fixation in the cervical spine have been documented recently, few anatomic studies concerning the cervical pedicle are available. This study was designed to evaluate the anatomy and adjacent neural relationships of the middle and lower cervical pedicle (C3-C7). The main objective is to provide accurate information for transpedicular screw fixation in the cervical region and to minimize complications by providing a three-dimensional orientation.

METHODS

Twenty cadavers were used to observe the cervical pedicle and its relationships. After removal of the posterior bony elements, including spinous processes, laminae, lateral masses, and inferior and superior facets, the isthmus of the pedicle was exposed. Pedicle width, pedicle height, interpedicular distance, pedicle-inferior nerve root distance, pedicle-superior nerve root distance, pedicle-dural sac distance, medial pedicle-dural sac distance, mean angle of the pedicle, root exit angle, and nerve root diameter were measured.

RESULTS

The results indicate that there was no distance between the pedicle and the superior nerve root and between the pedicle and the dural sac in 16 specimens, whereas there was a slight distance in the lower cervical region in the 4 other specimens. The mean distance between the pedicle and the inferior nerve root for all specimens ranged from 1.0 to 2.5 mm. The mean distance between the medial pedicle and the dural sac increased consistently from 2.4 to 3.1 mm. At C3-C7, the mean pedicle height ranged from 5.2 to 8.5 mm, and the mean pedicle width ranged from 3.7 to 6.5 mm. Interpedicular distance ranged from 21.2 to 23.2 mm. The mean root exit angle ranged from 69 to 104 degrees, with the largest angle at C3 and the smallest at C6. The mean angle of the pedicle ranged from 38 to 48 degrees. The nerve root diameter increased consistently from 2.7 mm at C3 to 3.8 mm at C6 and then decreased to 3.7 mm at the C7 level. Differences in measurements were considered statistically significant at levels ranging from P < 0.05 to P < 0.01.

CONCLUSION

This study indicates that improper placement of the pedicle screw medially and superiorly in the middle and lower cervical spine should be avoided and that the anatomic variations between individuals should be established by measurement.

Facet nerve blockade and radiofrequency neurotomy

Facet nerve blockade and RF neurotomy procedures are valuable techniques for diagnosis and management of spinal pain relating to facets. These procedures are rapidly evolving, and substantial improvements in patient selection and technique are certain to occur in the future. These are ideal neuroradiologic procedures, as they require the use of imaging equipment and can be performed safely and easily by procedurally oriented individuals.

Manual cervical traction reduces alpha-motoneuron excitability in normal subjects

The excitability of the Flexor Carpi Radialis alpha-motoneuron pool following manual cervical traction was assessed in twenty asymptomatic subjects, and compared to a hands only intervention. The excitability of the alpha-motoneuron pool was measured indirectly using the Hoffmann (H) reflex. H-reflex recruitment curves were taken to assess the number of alpha-motoneurons (alpha-motoneurons) firing in response to a given incremental increase in stimulation intensity. The rate of rise of the slope of the H-reflex recruitment curve (Hslp) was assessed using linear regression. Following manual cervical traction Hslp was significantly lower than pre-intervention trials. Manual cervical traction, therefore, reduced the excitability of the Flexor Carpi Radialis alpha-motoneuron pool. This effect was mediated by the central nervous system. There was no significant decrease in alpha-motoneuron excitability following the hands only intervention. Hslp was shown to be a more sensitive measure of changes in the H-reflex than the more traditional parameter of Hmax/Mmax ratio and should be used in future studies of this nature.

Vulnerability of the sympathetic trunk during the anterior approach to the lower cervical spine

STUDY DESIGN

Anatomic dissection and measurements of the cervical sympathetic trunk relative to the medial border of the longus colli muscle and lateral angulation of the sympathetic trunk relative to the midline on both sides were performed.

OBJECTIVE

To determine the course and location of the sympathetic trunk quantitatively and relate this to the vulnerability of the sympathetic trunk during the anterior approach to the lower cervical spine.

SUMMARY OF BACKGROUND DATA

The sympathetic trunk is sometimes damaged during the anterior approach to lower cervical spine, resulting in Horner's syndrome with its associated ptosis, meiosis, and anhydrosis. No quantitative regional anatomy describing the course and location of the sympathetic trunk and its relation to the longus colli muscle is available in the literature.

METHODS

In this study, 28 adult cadavers were used for dissection and measurements of the sympathetic trunk. The distance between the sympathetic trunk and the medial borders of the longus colli muscle at C6 and the angle of the sympathetic trunk with respect to the midline were determined bilaterally. The distance between the medial borders of the longus colli muscle from C3 to C6 and the angle between the medial borders of the longus colli muscle also were measured.

RESULTS

The sympathetic trunk runs in a superior and lateral direction, with an average angle of 10.4 +/- 3.8 degrees relative to the midline. The average distance between the sympathetic trunk and the medial border of the longus colli muscle is 10.6 +/- 2.6 mm. The average diameter of the sympathetic trunk at C6 is 2.7 +/- 0.6 mm. The length and width of the middle cervical ganglion were 9.7 +/- 2.1 mm and 5.2 +/- 1.3 mm, respectively. The distance between the medial borders of the longus colli muscle was 7.9 +/- 2.2 mm at C3, 10.1 +/- 3.1 mm at C4, 12.3 +/- 3.1 mm at C5, and 13.8 +/- 2.2 mm at C6, and the angle between the medial borders of the longus colli muscle was 12.5 +/- 4. 7 degrees.

CONCLUSIONS

The sympathetic trunk may be more vulnerable to damage during anterior lower cervical spine procedures because it is situated closer to the medial border of the the longus colli muscle at C6 than at C3. The longus colli muscles diverge laterally, whereas the sympathetic trunks converge medially at C6. As the transverse foramen or uncovertebral joint is exposed with dissection or transverse severance of the longus colli muscle at the lower cervical levels, the sympathetic trunk should be identified and protected.

[Vestibulospinal reactions in cervicogenic disequilibrium. Cervicogenic imbalance]

A functional cervical spine disorder is often the cause for persistent vertigo, which can last months or several years. The existence of cervical vertigo is not generally recognized, mainly because an objectivation of the cervical nystagmus is not easily understood by many examiners. In this study we examine additional parameters, which underline the diagnosis of cervical imbalance. The anamnestic statement of staggering refers to a disturbance of the vestibulospinal reactions. In 67 patients in which cervical imbalance was suspected the vestibulospinal reactions were monitored directly before and after manual therapy of the cervical spine. The cranio-corpo-graphie (CCG) and the posturography were used to monitor the results. A highly significant improvement of pathological vestibulospinal reactions was seen after chiropractic manipulation of the spine. These results show that a functional disorder of the cervical vertebrae influences the vestibulospinal reactions. The pathological deficit of the vestibulospinal reactions is not solely a phenomenon of peripheric labyrinth malfunction, failure in the brainstem or in the area of the cerebellum ("brain stem staggering"), but can also be viewed nearly regularly by cervical disturbance of the equilibrium. The results of the treatment can be observed within a few hours.

The optimal transarticular c1-2 screw length and the location of the hypoglossal nerve

BACKGROUND

Injury to the hypoglossal nerve is a complication associated with transarticular C1-2 screw placement. This complication can be caused by a misdirected or too long screw. Little is known about the optimal screw length and its relationship to the hypoglossal nerve.

METHODS

Twenty cervical spine specimens were used to study the optimal length of the transarticular C1-2 screw. Using the Magerl technique, a 3.0 mm drill bit was inserted into the C2 lateral mass, passing through the C1-2 facet joint and penetrating the upper portion of the ventral cortex of the lateral mass of the atlas. After drilling, the hole length was measured between the dorsal cortex of the C2 inferior articular process and the ventral cortex of the C1 lateral mass. In addition, six sagittal-sectioned cadavers were carefully dissected to observe the location of the hypoglossal nerve in the anterior aspect of the atlantoaxial region.

RESULTS

The results of the measurements showed that the mean optimal screw path length for all specimens was 38.1 +/- 2.2 mm with a range of 34-43 mm. There was no significant difference between sexes in the screw path length (p 0.05). The hypoglossal nerve lies vertically in front of the lateral portion of the C1 lateral mass and the C1-2 facet joint. The area where the hypoglossal nerve lies is approximately 2-3 mm lateral to the middle of the anterior aspect of the C1 lateral mass.

CONCLUSIONS

This study suggests that the mean optimal transarticular C1-2 screw length may be 38 mm; however, the determination of the accurate optimal C1-2 screw length should be made on an individual basis. Risk to the hypoglossal nerve can be eliminated if Magerl's technique is performed exactly.

Cervicogenic headache: techniques of diagnostic nerve blocks

Ther term cervicogenic headache (CEH) was introduced by Sjaastad and co-workers in 1983. In 1990 Sjaastad et al. published diagnostic criteria for CEH. In 1998 refinements of these criteria were published, emphasising the use of diagnostic nerve blocks in patients with CEH as important confirmatory evidence. However, the standardisation of diagnostic nerve blocks in the diagnosis of CEH remains to be defined. Herein we present an overview of diagnostic nerve blocks in the cervical area. Suggestions as to their role in the diagnosis of CEH are given.

Cervical flexion: a study of dynamic surface electromyography and range of motion

BACKGROUND

In the comprehensive assessment of painful conditions, dynamic surface electromyography (sEMG) and range of motion (ROM) recordings can provide information regarding muscle spasm, antalgic postures, fear of pain (protective guarding), muscle injury, and disordered movement caused by pain. This study examines ROM and sEMG patterns observed during cervical flexion.

OBJECTIVE

To demonstrate 2 distinctive sEMG recruitment and dynamic ROM patterns observed during cervical flexion and return to mid-line.

DESIGN

Single-subject design with independent measurement of dynamic ROM and sEMG.

SETTING

Applied clinical setting.

PARTICIPANTS

Two subjects with normal ROM and cervical muscles were studied.

MAIN OUTCOME MEASURE

One subject was studied with sEMG. looking at the cervical paraspinals and sternocleidomastoid muscles; the other subject was studied with an active ROM device. Three cervical movements were studied: lower cervical flexion, atlantoaxial (upper) cervical flexion, and a combination upper/lower cervical flexion.

RESULTS

The active ROM device indicates larger movements (higher degrees of flexion) for the lower cervical flexion compared with upper flexion. The combined movement indicates a differential movement from 2 spinal segments. The sEMG recordings indicated differential recruitment patterns. The sternocleidomastoid recruits briskly during the flexion phase of the upper cervical flexion movement, whereas the cervical paraspinals recruit briskly during return to mid-line when the lower cervical flexion is used. The combined upper then lower cervical flexion movement recruits both sets of muscles.

CONCLUSIONS

The results of the study indicate 2 distinct movement patterns associated with upper versus lower cervical flexion and 2 distinct sEMG recruitment patterns. The study suggests that these 2 distinct movements involve 2 distinct cervical segments and are associated with recruitment of different muscle groups. Applied clinical research on the cervical spine should use sEMG recordings to assess both the upper and lower flexion movements as the standard for the study of cervical flexion.

Somatic (craniocervical) tinnitus and the dorsal cochlear nucleus hypothesis

PURPOSE

Of all nonauditory sensory systems, only the somatosensory system seems to be related to tinnitus (eg, temporomandibular joint syndrome and whiplash). The purpose of this study is to describe the distinguishing characteristics of tinnitus associated with somatic events and to use these characteristics to develop a neurological model of somatic tinnitus.

MATERIALS AND METHODS

Case series.

RESULTS

Some patients with tinnitus, but no other hearing complaints, share several clinical features including (1) an associated somatic disorder of the head or upper neck, (2) localization of the tinnitus to the ear ipsilateral to the somatic disorder, (3) no vestibular complaints, and (4) no abnormalities on neurological examination. Pure tone and speech audiometry of the 2 ears is always symmetric and usually within normal limits. Based on these clinical features, it is proposed that somatic (craniocervical) tinnitus, like otic tinnitus, is caused by disinhibition of the ipsilateral dorsal cochlear nucleus. Nerve fibers whose cell bodies lie in the ipsilateral medullary somatosensory nuclei mediate this effect. These neurons receive inputs from nearby spinal trigeminal tract, fasciculus cuneatus, and facial, vagal, and glossopharyngeal nerve fibers innervating the middle and external ear.

CONCLUSIONS

Somatic (craniocervical) modulation of the dorsal cochlear nucleus may account for many previously poorly understood aspects of tinnitus and suggests novel tinnitus treatments.

Laminoplasty--a possible treatment for cervicogenic headache? Some ideas on the trigger mechanism of CeH

Cervicogenic headache (CeH) has been treated successfully by ventral decompressive surgery and segmental fusioning. Usually ventral fusioning is performed during one operation on one or two neighbouring segments only. We performed dorsal decompressive laminotomy and laminoplasty on eight patients with more than two segmental degenerative diseases narrowing the cervical spinal canal. The bilateral sawn laminae were moved dorsally and fixed with miniplates and screws. Six patients were relieved from headache and two improved postoperatively. Ventral decompressive surgery and fusioning frees from irritating mechanisms all nociceptively innervated tissues such as disc, dorsal ligament, facet joint capsule, nerve root and dura. On the other hand, after dorsal laminoplasty only the dura is freed from irritation or compression. Relief of headache after this surgical treatment shows that the dura, with its nociceptive nerve fibres, could be an important trigger mechanism of CeH.

The spinal accessory nerve distal to the posterior triangle

Thirty cadaver necks were dissected to determine the course of the accessory nerve distal to the posterior triangle. The nerve was found to have a constant course on the deep surface of the trapezius muscle. This has clinical implications for surgery in the region.

[Whiplash injuries of the cervical spine. Neurologic contribution to diagnosis. Therapy and expert evaluation]

The cervical spine is an extremely complex functional unit and has always been the subject of impassioned discussions among surgeons, orthopedic specialists and neurologists. In the presence of injuries affecting this section of the spine, which sometimes have grave consequences--including implications for legal insurance aspects, neurologists are usually at the end of the line when it comes to diagnosis and treatment. In fact, in view of the clinical and technical neurophysiological options available to neurologists, it would be desirable for them to be involved as early as possible. In this paper the relative value of neurology, compared with orthopedics and surgery, in the diagnosis and treatment of whiplash injury to the cervical spine is discussed. The newer options available--particularly in neurophysiology--are highlighted, as are the differential diagnosis and problems concerned with official expert assessments, which also involve other specialties.

Direct innervation of sensory fibers from the dorsal root ganglion of the cervical dura mater of rats

STUDY DESIGN

Sensory innervation in the cervical dura mater of rats was investigated immunohistochemically in whole tissues and transverse sections of the decalcified vertebral column.

OBJECTIVE

To investigate the origin and distribution of sensory innervation in the cervical dura mater.

SUMMARY OF BACKGROUND DATA

It has been generally accepted that irritation of the cervical structures is one of the major causes of pain in the neck and the upper extremities. Sensory fibers in the cervical dura mater are possible mediators of pain. However, there is little information about sensory innervation in the cervical dura mater, including the epiradicular sheath.

METHODS

Ten Wistar rats were used for wholemount immunohistochemical observations of the cervical dura mater. The vertebral columns of five rats were processed for immunohistochemistry after decalcification. In all specimens, sensory fibers were demonstrated by the peptide immunohistochemistry, and sensory innervation was examined.

RESULTS

The cervical dura mater was arbitrarily divided into three areas: ventral, dorsal, dorsal root ganglion. A large number of fibers were in the dorsal root ganglion area and were distributed in the corresponding segments. Some calcitonin gene-related peptide immunoreactive fibers in the dorsal root ganglion were directly innervated from dorsal root ganglion area neurons and did not form nerve bundles, similar to the sinuvertebral nerve. Several immunoreactive fibers were seen in the ventral area; fibers were rarely observed in the dorsal area.

CONCLUSIONS

A large number of sensory fibers are segmentally distributed in the cervical dura mater, and some of them are directly traced from dorsal root ganglion neurons.

The location of the spinal nerve root on plain radiographs of the cervical spine

Twelve cervical spines from C2 to T1 were harvested from embalmed cadavers to study the location of the nerve root on plain radiographs. After removal of the soft tissue, the spinal nerves just lateral to the transverse processes were exposed and injected with lead oxide. Plain radiographs including anteroposterior (AP) and left and right oblique views were taken. Angular and linear measurements were performed directly on the radiographs. Results showed that the average frontal angle of the nerve root for all levels was 155 degrees on the AP view, 108 degrees on the foraminal side of the oblique view, and 153 degrees on the opposite side of the oblique view. The nerve root height for all levels averaged 4.7 +/- 0.5 mm. The interpedicular space height increased consistently from 7.8 +/- 0.7 mm at C3-C4 to 9.0 +/- 1.3 mm at C6-C7 except at C2-C3. The nerve root height with respect to the interpedicular space height was 56.2% at C2-C3, 57.8% at C4-C5, and 53.7% at C6-C7. A knowledge of the location of the cervical nerve root related to plain radiographs may enhance the value of plain radiographs in the diagnosis and treatment of cervical spinal disorders.

Percutaneous radio-frequency neurotomy for chronic cervical zygapophyseal-joint pain

BACKGROUND

Chronic pain in the cervical zygapohyseal joints is a common problem after whiplash injury, but treatment is difficult. Percutaneous radiofrequency neurotomy can relieve the pain by denaturing the nerves innervating the painful joint, but the efficacy of this treatment has not been established.

METHODS

In a randomized, double-blind trial, we compared percutaneous radio-frequency neurotomy in which multiple lesions were made and the temperature of the electrode making the lesions was raised to 80 degrees C with a control treatment using an identical procedure except that the radio-frequency current was not turned on. We studied 24 patients (9 men and 15 women; mean age, 43 years) who had pain in one or more cervical zygapophyseal joints after an automobile accident (median duration of pain, 34 months). The source of their pain had been identified with the use of double-blind, placebo-controlled local anesthesia. Twelve patients received each treatment. The patients were followed by telephone interviews and clinic visits until they reported that their pain had returned to 50 percent of the preoperative level.

RESULTS

The median time that elapsed before the pain returned to at least 50 percent of the preoperative level was 263 days in the active-treatment group and 8 days in the control group (P=0.04). At 27 weeks, seven patients in the active-treatment group and one patient in the control group were free of pain. Five patients in the active-treatment group had numbness in the territory of the treated nerves, but none considered it troubling.

CONCLUSIONS

In patients with chronic cervical zygapophyseal-joint pain confirmed with double-blind, placebo-controlled local anesthesia, percutaneous radio-frequency neurotomy with multiple lesions of target nerves can provide lasting relief.

Localization, regulation and functions of neurotransmitters and neuromodulators in cervical sympathetic ganglia

Cervical sympathetic ganglia represent a suitable model for studying the establishment and plasticity of neurochemical organization in the nervous system since sympathetic postganglionic neurons: (1) express several neuromediators, i.e., short acting transmitters, neuropeptide modulators and radicals, in different combinations; (2) receive synaptic input from a limited number of morphologically and neurochemically well-defined neuron populations in the central and peripheral nervous systems (anterograde influence on phenotype); (3) can be classified morphologically and neurochemically by the target they innervate (retrograde influence on phenotype); (4) regenerate readily, making it possible to study changes in neuromediator content after axonal lesion and their possible influence on peripheral nerve regeneration; (5) can be maintained in vitro in order to investigate effects of soluble factors as well as of membrane bound molecules on neuromediator expression; and (6) are easily accessible. Acetylcholine and noradrenaline, as well as neuropeptides and the recently discovered radical, nitric oxide, are discussed with respect to their localization and possible functions in the mammalian superior cervical and cervicothoracic (stellate) paravertebral ganglia. Furthermore, mechanisms regulating transmitter synthesis in sympathetic neurons in vivo and in vitro, such as soluble factors, cell contact or electrical activity, are summarized, since modulation of transmitter synthesis, release and metabolism plays a key role in the neuronal response to environmental influences.

The quantitative anatomy of the cervical nerve root groove and the intervertebral foramen

STUDY DESIGN

The present study evaluated the cervical nerve groove and intervertebral foramen using dried vertebrae and cadaveric cervical spine.

OBJECTIVES

To measure the cervical nerve groove in eight linear and one angular dimensions and the intervertebral foramen in two linear diameters.

SUMMARY OF BACKGROUND DATA

Several anatomic studies of the cervical spine exist, but very little quantitative data have been reported on the cervical nerve groove.

METHODS

Dried cervical vertebrae, C3-C7, from 41 complete vertebral sets (205 vertebrae) and 14 cadaveric cervical spine were obtained for the present study. Anatomic evaluation focused on the cervical nerve groove for dry specimens and intervertebral foramen for cadaveric specimens. Ten linear and one angular measurements were made bilaterally. The mean, range, and standard deviation were calculated for all of the specimens and for male and female specimens separately.

RESULTS

Differences in dimensions of male and female specimens were not found to be statistically significant. The average lengths of the medial zone and distances from the midline of the vertebral body to the anterior border of the medial zone for male and female specimens consistently increased from C3 to C7. The width of the medial zone was larger in C3 than that of C4, C5, and C6 in male and female specimens. The minimum width for all levels ranged 1-2 mm. The medial zone depths gradually increased from C3 (3.2 mm for male and 2.3 mm for female specimens) to C7 (4.9 mm for male and 4.4 mm for female specimens). The smallest anteroposterior distances from the posterior midpoint of the lateral mass to the posterior border of the nerve groove were found in C7 (6.7 mm for male and 6.1 mm for female specimens). The general trend of the foraminal height and width increased from the cephalad to caudal except at C2-C3.

CONCLUSIONS

These data may enhance understanding of the important bony elements associated with the cervical spinal nerves and roots as they pass through the cervical nerve groove and the intervertebral foramen.

Cervical vertigo--reality or fiction?

Neck afferents not only assist the coordination of eye, head, and body, but they also affect spatial orientation and control of posture. This implies that stimulation of, or lesions in, these structures can produce cervical vertigo. In fact, unilateral local anesthesia of the upper dorsal cervical roots induces ataxia and nystagmus in animals, and ataxia without nystagmus in humans. If cervical vertigo exists outside these experimental conditions, it is obviously characterized by ataxia and unsteadiness of gait, and not by a clear rotational or linear vertigo. Neurological, vestibular, and psychosomatic disorders must first be excluded before the dizziness and unsteadiness in cervical pain syndromes can be attributed to a cervical origin. To date, however, the syndrome remains only a theoretical possibility awaiting a reliable clinical test to demonstrate its independent existence.

Connections from upper cervical inspiratory neurons to phrenic and intercostal motoneurons studied with cross-correlation in the decerebrate rat

We examined the synaptic connections from upper cervical inspiratory neurons to phrenic and intercostal motoneurons in decerebrate rats using cross-correlation. Upper cervical inspiratory neurons (n = 79) were recorded from the C1 and C2 segments of the spinal cord in 38 vagotomized, paralyzed, ventilated, and decerebrate rats. The neurons were identified by their inspiratory firing pattern and antidromic activation from the ipsilateral spinal cord at C7. Whole-nerve recordings were made using bipolar electrodes from the central cut ends of the C5 phrenic nerve and the external and internal intercostal nerves at various thoracic levels. Cross-correlation histograms were computed between these recordings to detect short time-scale synchronizations indicative of synaptic connections. The 55 cross-correlation histograms computed between the upper cervical inspiratory neurons and the ipsilateral phrenic nerve showed seven (13%) narrow peaks (mean half-amplitude width +/- SD, 1.09 +/- 0.15 ms) at short latencies (mean latency +/- SD, 1.29 +/- 0.26 ms) suggestive of monosynaptic excitation, and four (7%) broader peaks (mean half-amplitude width +/- SD, 1.50 +/- 0.17 ms) at short latencies (mean latency +/- SD, 1.40 +/- 0.24 ms) suggestive of oligosynaptic excitation. Another 14 (25%) cross-correlation histograms displayed a central broad peak (mean half-amplitude width +/- SD, 1.59 +/- 0.23 ms) suggestive of common activation. The eight cross-correlation histograms computed between the upper cervical inspiratory neurons and the contralateral phrenic nerve were featureless. The 77 cross-correlation histograms computed between the upper cervical inspiratory neurons and the internal and external intercostal nerves at various thoracic levels (T2-8) showed no peaks suggestive of synaptic connections. We conclude that some upper cervical inspiratory neurons make monosynaptic and paucisynaptic connections to phrenic motoneurons but not to intercostal motoneurons.

Positions of dorsal root ganglia in the cervical spine. An anatomic and clinical study

STUDY DESIGN

The authors investigated the positions of dorsal root ganglia and the relation of the location to symptoms and to the effects of nerve root infiltration in the cervical spine anatomically and clinically.

OBJECTIVES

To clarify normal variation of positions of dorsal root ganglia and the relation of the location of dorsal root ganglia to symptoms and to the effects of nerve root infiltration.

SUMMARY OF BACKGROUND DATA

The dorsal root ganglia of the spinal nerve has attracted much attention as an important structure in the mechanisms of radicular symptoms in the lumbar spine. Although the position of the dorsal root ganglia in the lumbar spine has been classified recently, there are few reports regarding the dorsal root ganglia in the cervical spine.

METHODS

The positions of dorsal root ganglia were divided into two types: proximally situated and distally situated. The positions of dorsal root ganglia in the anatomic and clinical cases were compared. The relation of the positions of dorsal root ganglia to symptoms and to the clinical effects of nerve root infiltration were analyzed.

RESULTS

There was no statistically significant difference in positions of dorsal root ganglia in C6 nerve roots between anatomic and clinical cases. In addition, there was no relation between symptoms and the positions of dorsal root ganglia in clinical cases. However, there was a significant difference in positions of dorsal root ganglia in C7 nerve roots between anatomic and clinical cases. Nerve root infiltration was significantly more effective in the distally situated type of dorsal root ganglia.

CONCLUSIONS

This study defined the normal variation of the positions of dorsal root ganglia. The results strongly suggest that some attention should be paid to the position of dorsal root ganglia in the diagnosis and treatment of cervical radiculopathy.

Cervical spondylotic myelopathy. Clinicopathologic study on the progression pattern and thin myelinated fibers of the lesions of seven patients examined during complete autopsy

STUDY DESIGN

This study was designed to reveal the progression pattern and essential histological findings of the lesions in the spinal cord affected by cervical spondylotic myelopathy.

OBJECTIVES

The purpose of this study was to gain new information about symptom progression and recovery in cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

The characteristics of the distribution and the progression pattern of the lesions and whether demyelination and remyelination processes actually occur in cervical spondylotic myelopathy remain unclear.

METHODS

Tissues from seven patients with cervical spondylotic myelopathy were taken during autopsy and examined macroscopically and microscopically. An ultrastructural examination of spinal cord from two patients was also performed.

RESULTS

The anterior horn and intermediate zone of the gray matter in the compressed segments showed atrophy in all the cases and in one, atrophy was limited to these areas. Atrophy and myelin pallor in the lateral and posterior funiculi were observed in six patients, and the lateral funiculi of two were severely affected. Many thin myelinated fibers and denuded axons were demonstrated ultrastructurally in the damaged white matter of two patients.

CONCLUSIONS

There appears to be a common pattern of lesion progression in cervical spondylotic myelopathy: atrophy and neuronal loss in the anterior horn and intermediate zone develop first, followed by degeneration of the lateral and posterior funiculi. Eventually, marked atrophy develops throughout the entire gray matter and severe degeneration occurs in the lateral funiculus. Furthermore, the existence of thin myelinated fibers in the white matter suggests focal demyelinating and remyelinating processes occur in cervical spondylotic myelopathy.

Prevalence of cervical spondylotic radiculopathy: a door-to-door survey in a Sicilian municipality

INTRODUCTION

Because of the limited information on cervical spondylotic radiculopathy, we conducted a door-to-door two-phase survey in a Sicilian municipality.

MATERIAL AND METHODS

We first screened for cervical spondylotic radiculopathy among the inhabitants of the municipality: (N = 7653, as of the prevalence day, November 1, 1987). Study neurologists then investigated those subjects suspected to have had a cervical spondylotic radiculopathy. Diagnoses were bases on specified criteria.

RESULTS

We found 27 subjects affected by CSR (17 definite, 10 possible). Prevalence (cases per 1000 population) was 3.5 in the total population; it increased to a peak at age 50-59 years, and decreased thereafter. The age-specific prevalence was consistently higher in women.

CONCLUSIONS

Comparison with other prevalence studies shows similar age-specific patterns, but different magnitudes, which may partly reflect methodologic differences across studies.