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Biomedical subjects

N Bogduk

Publications and source records attributed to N Bogduk.

At least 109 records · Page 6Linked to original sources
PubMed1987

Technical limitations to the efficacy of radiofrequency neurotomy for spinal pain.

Prompted by clinical failures of percutaneous radiofrequency neurotomy in the treatment of back pain and neck pain, we performed a study to determine the shape and size of lesions made by radiofrequency electrodes. Experimental lesions were made in egg white and fresh meat at temperatures recommended in clinical practice. The cardinal finding was that lesions do not extend distal to the tip of the electrode. They only extend radially around the electrode tip in the shape of an oblate spheroid, with a maximal effective radius of only 2 mm. Consequently, if electrodes are directed perpendicularly onto a nerve, the nerve may not be encompassed by the lesion generated. Some of the clinical failures of percutaneous medial branch neurotomy ("facet rhizotomy") may be due to this phenomenon. We suggest modified techniques for medial branch neurotomy in which the electrodes are introduced parallel to the target nerve whereupon it is more readily encompassed by the radial spread of the lesion.

Back Pain↗
PubMed1986

On the concept of third occipital headache.

One of the putative causes of headache is osteoarthritis of the C2-3 zygapophysial joint. A technique for blocking the third occipital nerve which innervates this joint was devised and used as a screening procedure for headache mediated by this nerve. Seven out of ten consecutive patients presenting with suspected cervical headache were found to suffer pain mediated by the third occipital nerve and stemming from a C2-3 zygapophysial joint. Because third occipital headache may be indistinguishable clinically from tension or other forms of headache, third occipital nerve blocks are advocated as means of establishing this largely unrecognised diagnosis.

Adult↗
PubMed1985

Cervical headache.

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Atlanto-Axial Joint↗
PubMed1985

Low back pain.

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Back Pain↗
PubMed1984

Low pharmacological responsiveness of the vertebro-basilar circulation in Macaca nemestrina monkeys.

We have examined the responsiveness of the vertebro-basilar circulation of the anesthetized Macaca nemestrina monkey to vasoactive agents infused directly into the artery. Infusion of noradrenaline caused a slight increase in vertebral arterial resistance. This constriction was less than that seen in previous experiments with either the internal or vertebral arterial resistance. This constriction was less than that seen in previous experiments with either the internal or external carotid arteries. In the presence of vasodilatation caused by inhalation of a CO2-rich gas mixture, this constriction became a dilatation. Serotonin was without significant effect on the vertebral arterial bed. Bradykinin, histamine and prostaglandin E1 all produced slight dilatation, with bradykinin being the most potent. In all cases the concentration required to produce an effect on the vasculature was much greater in the vertebral circulation than it is in the internal carotid and extracerebral circulations. We conclude that the intact vertebro-basilar circulation is much less sensitive to vasoactive agents than experiments with isolated segments of these arteries would indicate and that therefore these agents are unlikely to play a significant part in the pathogenesis of vertebro-basilar migraine.

Alprostadil↗
PubMed1984

The applied anatomy of the thoracolumbar fascia.

The thoracolumbar fascia was studied by dissection in ten adult human cadavers. The posterior layer of this fascia was found to consist of two laminae. The superficial lamina is formed by the aponeurosis of latissimus dorsi. The deep lamina consists of bands of fibers passing caudolaterally from the midline. Both laminae form a retinaculum over the back muscles, and the deep lamina constitutes a series of accessory posterior ligaments that anchor the L2 to L5 spinous processes to the ilium and resist flexion of the lumbar spine. The function of these ligaments is enhanced by the contraction of the back muscles and the action of certain, restricted portions of the abdominal muscles.

Adult↗
PubMed1984

Lateral subluxation of the atlas in rheumatoid arthritis: a case report and post-mortem study.

The atlantoaxial joints of a patient with lateral subluxation of the atlas were studied post mortem by dissection. There was severe erosion of the left lateral atlantoaxial joint and an asymmetrical erosion of the cartilages of the median atlantoaxial joint which prevented reduction of the lateral subluxation. The atlantoaxial ligaments were remarkably intact. It is emphasised that osseous factors rather than ligaments confer lateral stability to the atlantoaxial joints and that destruction of these leads to lateral subluxation.

Arthritis, Rheumatoid↗
PubMed1984

Decreased carotid arterial resistance in cats in response to trigeminal stimulation.

Stimulation of the trigeminal nerve or ganglion in the cat caused a frequency-dependent reduction in carotid vascular resistance. Systemic arterial blood pressure (SABP) decreased at low frequencies (0.2 to 5 sec-1) and increased at higher frequencies, thus increasing carotid blood flow at the higher frequencies. The effect on resistance was predominantly ipsilateral and was unaltered by cervical sympathectomy, but was abolished or substantially reduced by section of the trigeminal root proximal to the ganglion. Diminution of carotid vascular resistance was replicated by stimulation of the greater superficial petrosal (GSP) nerve without any change in SABP. Section of the seventh cranial nerve reduced or abolished the response to stimulation of the trigeminal nerve but not that from the GSP nerve. The trigeminal response was prevented by ganglion-blocking drugs in seven out of eight cats. The resistance response was unaffected by noradrenergic, cholinergic, serotonergic, and histamine-2 blocking agents. No neural connection could be demonstrated between the GSP and the trigeminal ganglion, and the vascular response to GSP stimulation persisted after trigeminal section. It is concluded that activation of the trigeminal system increases carotid blood flow by a pathway involving the seventh cranial nerve, the GSP and Vidian nerves, and a parasympathetic synapse employing an unconventional transmitter. A varying proportion of the response (greatest in the third division) may be mediated by antidromic activation of trigeminal nerves. These findings may have clinical implications for the vascular changes of migraine and other facial pain.

Animals↗
PubMed1984

Neck pain.

Any structure innervated by the cervical spinal nerves can be a primary source of neck pain and referred pain to the head, upper limb or chest wall. The most likely sources of chronic pain are the cervical intervertebral discs and the cervical zygapophyseal joints. Disc pain can be diagnosed by provocative disc stimulation; zygapophyseal joint pain can be diagnosed by local anaesthetic blocks of the cervical dorsal rami. Disc pain can be treated by anterior cervical fusion and zygapophyseal pain by percutaneous radiofrequency neurotomy.

Arm↗
PubMed1983

The innervation of the lumbar spine.

The lumbar intervertebral discs are innervated posteriorly by the sinuvertebral nerves, but laterally by branches of the ventral rami and grey rami communicantes. The posterior longitudinal ligament is innervated by the sinuvertebral nerves and the anterior longitudinal ligament by branches of the grey rami. Lateral and intermediate branches of the lumbar dorsal rami supply the iliocostalis lumborum and longissimus thoracis, respectively. Medial branches supply the multifidus, intertransversarii mediales, interspinales, interspinous ligament, and the lumbar zygapophysial joints. The distribution of the intrinsic nerves of the lumbar vertebral column systematically identifies those structures that are potential sources of primary low-back pain.

Animals↗
PubMed1982

The human lumbar dorsal rami.

The L 1-4 dorsal rami tend to form three branches, medial, lateral, and intermediate, which are distributed, respectively, to multifidus, iliocostalis, and longissimus. The intertransversarii mediales are innervated by a branch of the dorsal ramus near the origin of the medial branch. The L 4 dorsal ramus regularly forms three branches while the L 1-3 levels the lateral and intermediate branches may, alternatively, arise from a short common stem. The L 5 dorsal ramus is much longer than the others and forms only a medial and an intermediate branch. Each lumbar medial branch innervates two adjacent zygapophysial joints and ramifies in multifidus, supplying only those fascicles which arise from the spinous process with the same segmental number as the nerve. The comparative anatomy of the lumbar dorsal rami is discussed and the applied anatomy with respect to 'rhizolysis', 'facet denervation' and diagnostic paraspinal electromyography is described.

Adult↗
PubMed1982

The menisci of the lumbar zygapophysial joints.

In a study of 82 lumbar zygapophysial joints three types of intra-articular structures were identified. They were adipose tissue pads and fibro-adipose meniscoids, both located at the superior and inferior poles of the joint, and connective tissue rims, located along the dorsal and ventral margins. Every lumbar zygapophysial joint contained at least one of these structures and 47 contained more than one type. Connective tissue rims are short, central projections of the joint capsule and do not enter between the articular surfaces. Adipose tissue pads are covered by synovium and fill the subcapsular space at the superoventral and inferodorsal poles of the joint. Fibro-adipose meniscoids, also covered by synovium, project from the joint capsule at the superior and inferior poles and enter between the articular surfaces. Adipose tissue pads and fibro-adipose meniscoids are probably derived from a common primitive mesenchymal meniscus which primarily differentiates into a fatty structure. The fibrous component of fibro-adipose meniscoids then secondarily develops as a result of compression of the tip of the fatty structure between the articular surfaces. The function of these intra-articular structures is not evident but may be related to protection of the articular processes as they subluxate during flexion and extension. Meniscus entrapment in the lumbar zygapophysial joints has been proposed as a cause of acute locked back, but the present morphological data are inconsistent with this view.

Adipose Tissue↗
PubMed1981

Lumbar lateral branch neuralgia: a complication of rhizolysis.

Rhizolysis has been regarded as a controversial, but safe, procedure for the treatment of back pain. A case of a neuralgia-like pain syndrome resulting from transection of the lateral branches of the lumbar dorsal rami during rhizolysis is reported. The anatomy of the lumbar lateral branches is described, and their vulnerability is discussed. Attention is drawn to the likelihood of this complication with the use of rhizolysis in the vicinity of cutaneous branches of the dorsal rami

Adult↗
PubMed1981

The anatomy and physiology of the vertebral nerve in relation to cervical migraine.

The anatomy of the vertebral nerve was investigated in humans and in monkeys. The effect of stimulation of the vertebral nerve and the cervical sympathetic trunk in the monkey was studied. The vertebral nerves in man and monkey represent a series of deep grey rami communicantes which form intersegmental neural arcades around the vertebral artery between C7 and C3. Above C3 the vertebral artery is accompanied by direct branches from the C1-3 ventral rami. Electrical stimulation of either the vertebral nerve or the cervical sympathetic trunk had a minimal effect on vertebral blood flow. In contrast, sympathetic stimulation had pronounced effects on carotid flow and resistance. Anatomically and physiologically there are no grounds to support the hypothesis that irritation of the "vertebral nerve" is the pathogenetic mechanism of cervical migraine.

Animals↗
PubMed1981

Local anesthetic blocks of the second cervical ganglion: a technique with application in occipital headache.

Dissections of five human adult cadavers revealed that the C2 spinal ganglion bears a constant relationship to the dorsal aspect of the lateral atlanto-axial joint. Radiologically, the ganglion lies extradurally opposite the midpoint of the silhouette of the lateral atlanto-axial joint space. Needles can be introduced onto this target point using fluoroscopic control and used to perform selective local anesthetic blocks of the C2 spinal nerve. This technique is applicable in cases where it is difficult to decide on clinical grounds whether occipital headaches are due to an upper cervical abnormality or are a symptom of tension headache or common migraine. In particular the technique anesthetizes the otherwise inaccessible articular branches of the median and lateral atlanto-axial joints which may be an occult source of headache.

Adult↗
PubMed1981

An anatomical basis for the neck-tongue syndrome.

The C2 nerve roots and rami were dissected in five cadavers to explore the pathogenesis of Neck-Tongue Syndrome. The most likely cause of the simultaneous occurrence of suboccipital pain and ipsilateral numbness of the tongue is an abnormal subluxation of one lateral atlanto-axial joint with impaction of the C2 ventral ramus against the subluxated articular processes.

Adult↗