Download Greater Occipital Nerve Block

Greater Occipital Nerve Block
John B. Ward, M.B., B.Ch.1
ABSTRACT
The occipital nerve block is used to diagnose and treat occipital neuralgia. The
clinical presentation of occipital neuralgia, the anatomy of the greater occipital nerve, and
the technique of the occipital nerve block is described.
KEYWORDS: Occipital neuralgia, occipital nerve block
Objectives: Upon completion of this article, the reader will understand the clinical presentation of occipital neuralgia and the technique of greater occipital nerve block.
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Disclosure: Statements have been obtained regarding the author’s relationships with financial supporters of this activity. There is no
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INDICATIONS
The occipital nerve block has been traditionally used to
diagnose and treat pain in the distribution of the occipital nerves (occipital neuralgia), which includes the
greater and lesser occipital nerves. The International
Headache Society specifically defines occipital neuralgia
as the pain that is relieved by local anesthetic block of the
involved nerve, thereby confirming the diagnosis. Other
pathologies that may cause occipital nerve irritation and
pain in its distribution include arthritis of the C2 cervical
spine, myofascial spasm, and referred pain from the ipsilateral trigeminal distribution through interneuronal
connections within the spinal cord. The trigeminal spinal
nucleus and the C2 root are in close proximity so local
anesthetic blocks to the occipital nerve may also decrease
pain in the ipsilateral trigeminal distribution.1
CLINICAL PRESENTATION
Occipital neuralgia as described by the International
Headache Society is a paroxysmal jabbing pain in the
distribution of the greater or lesser occipital nerves ac-
companied by diminished sensation or dysesthesia in
the affected area. It is associated with tenderness over
the affected nerve. Criteria for diagnosis include: (1)
pain in the distribution of the greater or lesser occipital
nerves; (2) a stabbing quality pain that occurs in paroxysms, which may ache between paroxysms; (3) the affected nerve is tender to palpate; and (4) the condition
is relatively easily treated with local anesthetic. The history and physical examination may elucidate the cause
of the occipital neuralgia in a particular patient. If there
is a strong history of myofascial irritation with trigger
points in the back of the neck and trapezius muscles, it
is likely that chronic muscle tension and spasm are contributing to the irritation of the occipital nerves. This
presentation is commonly bilateral but can be unilateral.
Occipital neuralgia may also present in the context of
migraine headaches with associated signs and symptoms. This presentation usually lasts from 1 to 3 days
and is typically unilateral. The pain may respond dramatically to vasoconstrictor therapy. Occipital neuralgia
may be due to craniocervical junction disease, which
may be degenerative or traumatic in origin. It is impor-
Neurological Office Procedures; Editor in Chief, Karen L. Roos, M.D.; Guest Editor, Karen L. Roos, M.D. Seminars in Neurology, Volume 23,
Number 1, 2003. Address for correspondence and reprint requests: John B. Ward, M.B., B.Ch., Department of Anesthesia, Indiana University
School of Medicine, 1120 South Drive, FH 204, Indianapolis, IN 46202. 1Associate Professor of Clinical Anesthesia, Indiana University School
of Medicine, and Director, Indiana University Chronic Pain Clinic, Indianapolis, Indiana. Copyright © 2003 by Thieme Medical Publishers,
Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 0271-8235,p;2003,23,01,059,062,ftx,en;sin00228x.
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SEMINARS IN NEUROLOGY/VOLUME 23, NUMBER 1 2003
tant to obtain appropriate spinal imaging together with
a careful neurological examination to confirm this diagnosis.
ANATOMY
The greater occipital nerve arises from the dorsal ramus
of the second cranial nerve (Fig. 1).2 It provides cutaneous innervation to the major portion of the posterior
scalp. It originates in the posterior neck, lateral to the
lateral atlantoaxial joint and deep to the oblique inferior
muscle where a communicating branch from the third
cranial nerve may join the greater occipital nerve. The
greater occipital nerve ascends in the posterior neck
over the dorsal surface of the rectus capitis posterior
major muscle, and then turns dorsally to pierce the
fleshy fibers of the semispinalis capitis, after which it
runs a short distance rostrally and laterally, and lies deep
to the trapezius muscle. The greater occipital nerve becomes subcutaneous slightly inferior to the superior
nuchal line by passing above an aponeurotic sling. This
sling is composed of insertions from the trapezius and
sternocleidomastoid muscles. At this point, the greater
occipital nerve is immediately medial to the occipital
artery.
GREATER OCCIPITAL NERVE
BLOCK TECHNIQUE
The patient is usually positioned in the sitting position
with the head either vertical or slightly flexed. The nerve
is relatively easy to locate along the superior nuchal line,
where it lies medial to the occipital artery, bilaterally. The
pulsation of the occipital artery is easy to palpate. Palpation in this area may elicit a paresthesia or uncomfortable
feeling in the distribution of the nerve. It is helpful if an
assistant provides support for the head anteriorly. The
scalp is prepped with alcohol. A mixture of local anesthetic and steroid is used, usually 2% lidocaine with either triamcinolone 10 to 20 mg or betamethasone 2 to 4
mg for a total volume of 3 mL of injectate. The technique is made easier if a control-type syringe is used for
aspiration and injection, as this can be performed with
one hand. Usually a 25 G needle, either 5⁄8 inch or 11⁄2
inch, can be used depending on the size of the patient.
The needle is directed at 90 degrees toward the occiput
until a bony endpoint is obtained. Aspiration is important to prevent intravascular injection, and in the case of
a history of a cranial defect, to prevent injection into the
cerebrospinal fluid. Approximately 1.0 cc is injected
around the nerve and an additional 1.0 cc on either side
of the nerve. When the needle is withdrawn, pressure
should be maintained over the site of injection to both
bathe the nerve trunk with the mixture and to achieve
hemostasis as the scalp has a rich vascular supply. Ample
time should be allowed for the local anesthetic to take effect, and the patient should be reevaluated in approximately 15 minutes. The lesser occipital nerves may be included by injecting more of the local anesthetic/steroid
mixture lateral to the greater occipital injection along the
superior nuchal line. If a small volume is used (approximately 1.0 cc) and is directed in the immediate vicinity of
the greater occipital nerve, it is somewhat more definitive
in distinguishing greater occipital neuralgia from surrounding myofascial-type pain, which will also be relieved by the injection of a larger volume.
COMPLICATIONS
There are relatively few complications because of the
superficial location of the nerve. However, intravascular
injection is a possibility. Careful aspiration is performed
prior to injection to avoid toxicity. Also, in advance, one
should elicit from the patient whether they have a cranial defect3 from prior surgery or trauma. Rarely, a patient may be rendered Cushingoid as a response to serial
injections of corticosteroids.4
REFERENCES
Figure 1 Anatomy of the greater occipital nerve.
1. Ploveran EJ, Kowacs PA, Tatsui CE, Lange MC, Ribas LC,
Wernek LC. Referred pain after painful stimulation of the
greater occipital nerve in humans: evidence of convergence of
GREATER OCCIPITAL NERVE BLOCK/WARD
cervical afferents on trigeminal nuclei. Cephalalgia 2001;21:
107–109
2. Anderson JE. Grant’s Atlas of Anatomy. 7th ed. Baltimore:
Williams & Wilkins Co.; 1978
3. Okuda Y, Matsumoto T, Shinohara M, Kitajima T, Kim P.
Sudden unconsciousness during a lesser occipital nerve block
in a patient with the occipital bone defect. Eur J Anaesthesiol
2001;18:829–832
4. Lavin PJ, Workman R. Cushings syndrome induced by serial
occipital nerve blocks containing corticosteroids. Headache
2001;41:902–904
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