Chapter 73 Head and Neck Blocks Flashcards
Absolute contraindications include
patient refusal,
local infection and sepsis, and increased intracranial pressure
(trigeminal ganglion block).
Relative contraindications
coagulopathy, anticoagulant therapy, history of facial trauma,
and pre-existing neurologic deficits. Allergy to medications used can be absolute or relative depending on the severity of the allergy.
The trigeminal ganglion resides in
the middle cranial fossa. It is situated in a fold of dura mater that forms
an invagination around the posterior two-thirds of the ganglion. This region is referred to as Meckel’s cavity and contains cerebrospinal fluid.
trigeminal ganglion bounded by
medially by the cavernous sinus and optic and trochlear
nerves; superiorly by the inferior surface of the temporal lobe of the brain; and posteriorly by the brain stem.
trigeminal ganglion formed by
the fusion of a series of cell bodies
that originate at the mid-pontine level of the brainstem
trigeminal ganglion divisions
ophthalmic (V1),
maxillary (V2), and mandibular (V3).
The ophthalmic
division is located
dorsally, the maxillary branch intermediate,
and the mandibular branch ventrally. The ophthalmic
division leaves the ganglion and passes into the orbit
through the superior orbital fissure.
ophthalmic
division further divides into
the supraorbital, supratrochlear, and nasociliary nerves which innervate the forehead and the nose.
The maxillary division exits the middle cranial fossa via
foramen
rotundum, crosses the pterygopalatine fossa, and enters
the orbit through the inferior orbital fissure.
Branches of maxillary division
infraorbital, superior alveolar, palatine and
zygomatic nerves which carry sensory information from the maxilla and overlying skin, the nasal cavity, palate,
nasopharynx and meninges of the anterior and middle cranial fossa
The mandibular division exits through
foramen ovale and divides into the buccal, lingual, inferior alveolar and auriculotemporal nerves. These nerves carry sensory input from the buccal region, the side of the head and scalp, and the lower jaw including teeth, gums, anterior two-thirds of the tongue, chin, and lower lip.
The motor component of V3 innervates
the several muscles
including the masseter, temporal, and medial and lateral pterygoids.
The ganglion interfaces with the autonomic
nervous system via
the ciliary, sphenopalatine, otic, and
submaxillary ganglia. It also communicates with the oculomotor, facial, and glossopharyngeal nerves
MAXILLARY NERVE BLOCK
most common indication
regional anesthesia for surgery of the upper jaw, but is also effective for acute postoperative pain control. it is indicated for the diagnosis and
treatment of chronic pain in the distribution of the maxillary division of the trigeminal nerve
MAXILLARY NERVE BLOCK
Technique
Place the patient in
the supine position. Palpate the mandibular notch located below the zygoma and anterior to the temporomandibular
joint. Under sterile conditions, anesthetize the skin over the notch. Insert the block needle (usually a
22-gauge, 8–10 cm, short-bevel or a same-size curved, blunt needle) in a horizontal plane through the mandibular notch until bone (lateral pterygoid plate) is touched (typically 4–5 cm). Withdraw the needle and redirect it anteriorly and superiorly
through the pterygomaxillary fissure into the
pterygopalatine fossa. Advance the needle approximately 0.25 to 0.5 cm at which depth a paresthesia is usually
perceived in the upper lip or teeth.
MAXILLARY NERVE BLOCK
Technique (Fluoroscopy)
If performed under
fluoroscopy, the needle is angled toward the superior portion of the pterygopalatine fossa, which appears as a
“V” on the lateral image. On an anteroposterior image, the needle tip should be above the level of the middle turbinate. Inject 3 to 5 ml of local anesthetic. If fluoroscopy
is used, 0.5 to 1.0 ml of contrast can be injected first to rule out intravascular placement of the needle
Neurolytic
blocks can be done with
6% phenol or absolute alcohol. After appropriate placement of the needle, up to 1.0 to 1.5 ml of the neurolytic solution is injected in 0.1-ml aliquots. The needle should then be flushed with 0.5 ml
of saline prior to removal.
Pulsed radiofrequency lesioning
can also be performed after a successful diagnostic block. Sensory stimulation is performed at 50 Hz, 1 V. Paresthesia in the upper teeth should be perceived at less than 0.3 V. Once confirmed, two or three 120-sec pulsed radiofrequency cycles are administered at 45V
MANDIBULAR NERVE BLOCK
Indications
regional anesthesia for surgery of the lower jaw, but is also effective for acute postoperative pain control. it is indicated for the diagnosis and treatment of chronic pain in the distribution of the mandibular division of the trigeminal nerve
MANDIBULAR NERVE BLOCK
area to anesthetize or treat pain is
the lower jaw and tongue.
MANDIBULAR NERVE BLOCK
Technique
once the lateral pterygoid plate has been touched with the block needle, withdraw it and redirect in a slightly caudal and posterior direction until a paresthesia is produced in the lower lip, lower jaw, or ipsilateral tongue or ear. The depth should not be more than 0.1 to
0.25 cm beyond the depth at which the lateral pterygoid plate was contacted. The total distance should not exceed 5.5 cm. After proper positioning, inject 2 to 3 ml of local anesthetic, remove the needle, and apply an ice pack to the side of the
face
MANDIBULAR NERVE BLOCK
using fluoroscopy
Since this technique involves blocking the nerve as it exits the
foramen ovale, a submental, oblique view can be obtained in order to verify the position of the needle tip in relation to foramen ovale. The needle tip should be adjacent to, or overlie, the shadow of the foramen ovale. To
rule out intravascular or intrathecal injection, instill 0.5 to 1.0 ml of contrast. If negative, inject the aforementioned
volume of local anesthetic. Chemical neurolysis can be
achieved using 6% phenol, 50% glycerol, or absolute alcohol. After a successful diagnostic block and after proper
positioning of the needle, up to 1.0 ml of the neurolytic solution is injected in 0.1-ml increments. Flush the needle with 0.5 ml normal saline before removing it.
MANDIBULAR NERVE BLOCK
For pulse
radiofrequency lesioning
perform sensory and motor stimulation at 50 Hz, 1 V, and 2 Hz, 2 V, respectively, to
check needle position. Paresthesia should be obtained at less than 0.3 V, and masseter contraction should be apparent at less than 0.6 V. Two to three 120-sec pulsed cycles
should be carried out at 45 V.
the most common indication for trigeminal
ganglion blockade
Tic douloureux (Trigeminal neuralgia (TN))
Indications for trigeminal
ganglion blockade
Secondary trigeminal neuralgias from injury to the major divisions or the distal branches of the ganglion, in the treatment of chronic, intractable cluster
headaches. Persistent idiopathic facial pain (formerly atypical facial pain)
MANDIBULAR NERVE BLOCK
Technique
Place the patient on the table in the supine position with the head slightly extended. Light sedation with midazolam and fentanyl is usually required. Sterilely prepare and drape the appropriateside, leaving the eye exposed. Utilizing continuous or
pulsed fluoroscopy, locate foramen ovale by rotating the C-arm image intensifier obliquely away from the nose approximately 20 to 30 degrees, and then angle the C-arm image intensifier approximately 30 to 35 degrees in the
caudocephalad direction to bring the foramen ovale into view.
MANDIBULAR NERVE BLOCK
Technique
Raise a skin wheal directly over the shadow of the foramen which will be ~2 to 2.5 cm lateral to the corner of the mouth. Insert a short, 16- or 18-gauge
angiocatheter through the skin wheal and advance to the hub. Insert a gloved finger into the oral cavity to confirm that the buccal mucosa has not been breached. Re-glove
before proceeding. Insert a 20- or 22-gauge, curved, blunt
block needle through the angiocatheter and advance a few
centimeters. Obtain a fluoroscopic image to check the trajectory
of the needle. The goal is to advance the needle in a coaxial fashion toward the foramen ovale. With respect to external
landmarks, the trajectory of the needle will be in a plane
slightly superior to the external auditory meatus and medially
toward the pupil in the midline. Advance the needle in 1- to 2-cm increments until bone is touched. Obtain a lateral image to check the position of the needle. If the foramen
has not been traversed, adjust the needle tip (usually posterior) and advance through the foramen a distance of
0.5 to 1.0 cm.
MANDIBULAR NERVE BLOCK
After a negative aspiration for CSF or blood
inject 0.5 to 1.0 ml of nonionic, water-soluble contrast to confirm position and filling of
Meckel’s cavity. Any vascular runoff requires repositioning of the needle. If cerebrospinal fluid is obtained, the needle tip can be withdrawn until fluid is no longer appreciated
MANDIBULAR NERVE BLOCK
If an abundant cerebrospinal fluid leak is present
the remainder of the procedure should be halted. With a significant
leak, a high spinal block can be caused with even low volumes of local anesthetic. A small leak of cerebrospinal fluid may or may not cause a high spinal and if present, the pain
practitioner should proceed with caution.
MANDIBULAR NERVE BLOCK
Drug and Dosing
Inject local anesthetic
in volumes of 0.25 to 0.5 ml at a time, up to 1 to 2 ml, and observe for effect. Remove the needle and apply
an ice pack to the cheek to decrease swelling.
For conventional radiofrequency lesioning, a 3- to 5-mm active-tip needle is placed. The target depth of the needle tip depends on the division of the trigeminal nerve that needs to be lesioned
The mandibular division is rostral
and lateral; the maxillary division is intermediate; and
the ophthalmic division is mostly cephalad and medial.
Location of the needle tip on the appropriate division/s is determined by
the response to sensory and motor stimulation (50 Hz, 1 V, and 2 Hz, 2 V, respectively) of
the ganglion. Paresthesia should be perceived at less than
0.3 V, with little to no muscle contraction of the masseter
muscle at 0.6 to 1.0 V.
conventional
radiofrequency
If no contraction is seen, then the tip of the needle is on
the ophthalmic or maxillary divisions.
conventional
radiofrequency
Once the patient senses paresthesia in the painful area
inject 0.5 ml of 0.25% bupivacaine or 0.2% ropivacaine with steroid. Wait 30 to 60 sec and begin lesioning at 60° C for 90 sec.
conventional
radiofrequency
For lesioning of
the ophthalmic division, assess the
corneal reflex during
and after each lesion. Lesioning is typically started at temperatures
of 55 to 65° C to preserve this reflex. One or two lesions are recommended. If the corneal reflex diminishes, lesioning should be stopped.
PULSED RADIOFREQUENCY
not a temperature-dependent technique. It is a nondestructive method of providing
long-term pain relief
PULSED RADIOFREQUENCY
Technique
After proper positioning of the
needle tip, perform two or three pulsed radiofrequency cycles for 120 sec each at 45 V. The temperature of the needle tip rarely exceeds 42° C, thus local anesthetic is not
required. If significant masseter contraction is noted during pulsing, inject 1 to 2 ml of local anesthetic to diminish
this, or hold the patient’s mouth closed with your hand while the cycles are completed.
trigeminal
ganglion blockade.
CHEMICAL NEUROLYSIS
Chemical neurolysis has been performed with phenol and
alcohol in the past, but their use is not currently recommended. chemical neurolytic of choice is
Glycerol
trigeminal
ganglion blockade.
CHEMICAL NEUROLYSIS
Once through the foramen ovale, advance the needle until
cerebrospinal fluid is observed returning through the needle. Place the patient in a semi-sitting position with the
neck flexed. Inject water-soluble, nonionic contrast solution in 0.1-ml aliquots (up to 0.5 ml) into the trigeminal cistern. Once the cistern is visualized,
draw back the contrast material by free flow. The
flow of contrast is slower than cerebrospinal fluid. Inject the same amount of glycerol into the cistern. Flush the needle with 0.5 ml of saline prior to removal. Keep the
patient in a semi-sitting position for 2 hr. During the procedure,
patients often report pain, burning, or paresthesia
in the affected division/s
COMPLICATIONS
in relation to procedures
complications considered for all neurolytic techniques,
radiofrequency thermal lesioning had the highest number of complications (29.2%) followed by glycerol
rhizotomy and balloon compression at 24.8% and 16.1%, respectively.
COMPLICATIONS
Retrobulbar hematoma (needle is advanced into the retrobulbar space)
Exophthalmus (secondary to bleeding in the retrobulbar space)
hematoma
Masseter weakness (especially with lesioning of the mandibular division. The incidence is highest with balloon microcompression)
Loss of the corneal reflex, keratitis (likely to occur after radio frequency lesioning and glycerol neurolysis), ulceration, and hypesthesia are
observed in 3% to 15% of patients after a neurolytic procedure. Corneal anesthesia
was highest for radiofrequency rhizotomy at 7%, and was observed with glycerol rhizotomy and balloon compression
at 3.7% and 1.5%, respectively. Anesthesia dolorosa (deafferentation pain) occurs in up to 4% of patients with radiofrequency, followed by glycerol
where it occurs in 2% of cases.
Other complications
include
meningitis, dural arteriovenous fistulae, rhinorrhea, transient cranial nerve deficits, tissue sloughing, and even death
Postprocedure trigeminal nerve sensory loss
an expected occurrence after a properly performed neurolytic procedure. The incidence with radiofrequency
rhizotomy is as high as 98%, followed by balloon compression (72%) and glycerol neurolysis (60%)
SPHENOPALATINE GANGLION
The ganglion resides in the pterygopalatine fossa. The fossa
is bordered anteriorly by the maxillary sinus; posteriorly by
the medial pterygoid plate; medially by the palatine bone;
and superiorly by the sphenoid sinus.
The pterygomaxillary
fissure and pterygopalatine foramen
The pterygomaxillary
fissure allows passage of a needle into the fossa, while the
pterygopalatine foramen is located medial to the ganglion
and is just posterior to the middle turbinate. The fossa is
approximately 1 cm wide and 2 cm high and resembles a V-shaped vase on a lateral fluoroscopic image.A large venous plexus overlies the fossa.
Foramen rotundum and
the pterygoid canal
Foramen rotundum and
the pterygoid canal are located on the superolateral and
inferomedial aspect of the fossa, respectively
The maxillary artery
resides in the pterygopalatine fossa
SPHENOPALATINE GANGLION is “suspended” from the maxillary nerve by the
pterygopalatine nerves and is medial to the maxillary nerve.
Posteriorly the ganglion is connected to the
vidian nerve which is formed by the deep
petrosal (sympathetic from the upper thoracic spinal cord) and greater petrosal (parasympathetic from the superior
salivatory nucleus) nerves.
SPHENOPALATINE GANGLION has efferent
branches and forms the
superior posterior lateral nasal and
pharyngeal nerves.
exit the SPHENOPALATINE GANGLION caudally
the greater and lesser palatine nerves
Sensory fibers arise from the maxillary
nerve, pass through the SPHENOPALATINE GANGLION, and innervate the
upper teeth, nasal membranes, soft palate, and some parts of the pharynx. A small number of motor nerves are believed to
travel with the sensory trunks
Indications for sphenopalatine ganglion block and neurolysis
include
sphenopalatine neuralgia, trigeminal neuralgia, migraine headaches, cluster headaches, atypical facial pain, and cancer of the tongue and floor of the mouth
Other reported therapeutic uses of sphenopalatine ganglion block include
sinus arrest in postherpetic neuralgia, vasomotor rhinitis,
complex regional pain syndrome of the lower extremity, low back pain, and post-traumatic headache.
The intranasal SPG block
allows absorption of local anesthetic from a cotton-tipped applicator
inserted into the nare.
The location of the SPG in relation to the middle turbinate as well as the lateral nasal mucosa
anesthetic of choice in the intranasal SPG block
Four percent cocaine is the local anesthetic of choice secondary to its inherent vasoconstrictor property. If this is not available or there is a contraindication to using cocaine, 1% to 2% lidocaine or 0.25% to 0.5% bupivacaine or ropivacaine can be used instead. If these are
chosen, the practitioner can pretreat the nare/s with neosynephrine
to produce vasoconstriction.
The intranasal SPG block
Technique
Place the patient in the
supine position. Estimate the depth of insertion by externally measuring the distance from the opening of the nare to the mandibular notch. Place a mark corresponding to this depth on the shaft of the cotton-tipped applicator. Soak the applicators
in the local anesthetic for several minutes. Slowly
insert the applicator into the nare and advance in a line parallel to the zygoma with the tip angled laterally. Do not
advance the applicator in a cephalad direction. The endpoint should be the depth marked on the applicator. Place a second applicator into the nare using the same technique, except
advance it ~ 0.5 to 1.0 cm deeper and superior
to the first. If resistance is encountered at any time, slightly withdraw and redirect the applicator. The second applicator is not a necessity and the nares of some patients may not accommodate it. Leave the applicator(s) in for 30 to 45 min
Signs of a successful block of the SPG include
ipsilateral tearing, conjunctival injection, and nasal congestion. If the SPG is a pain generator or transmitter, analgesia should also
be apparent.
In the intranasal SPG block, If after 20 to 30 min there are no signs of a block or the patient has not received any pain relief
additional local anesthetic may be needed and can be trickling down the shaft of the applicator. Remove the cotton-tipped applicators after 45 min even if there are no signs of a block
or analgesia. If there are no signs of a block or analgesia, the SPG may be too deep to be blocked by this technique, or is not involved in the transmission of pain.
The infrazygomatic approach to SPG blockade
Setup
fluoroscopic guidance is highly recommended. Noninvasive monitors should be used to record vital signs. Light sedation with midazolam and fentanyl can be used, but on occasion, deeper sedation may be
necessary for radiofrequency lesioning. For pulsed radiofrequency, heavy sedation is not required.
Place the patient in the supine position. Sterilely prep and drape the appropriate side of the face. Obtain a lateral fluoroscopic image.
The infrazygomatic approach to SPG blockade
Technique
Palpate the mandibular notch and anesthetize
the skin. If the notch is not palpable, identify the
notch on a lateral fluoroscopic view. Identify the pterygopalatine
fossa (appears as a “V”) on the lateral image and
superimpose the right and left fossae. The
block can be performed with a 4.5-inch, 22-gauge, shortbevel
needle with the distal tip bent at a 30-degree angle, or with a curved, blunt, 10-cm, 20- or 22-gauge needle. Anesthetize the skin and insert a 1.25-inch, 16-gauge angiocatheter
through the skin and advance until it is just medial to the ramus of the mandible. This can be checked on an
anteroposterior (AP) image. Pass the block needle through the angiocatheter and advance it medial, anterior, and slightly cephalad. Obtain a lateral image to check the direction of the needle. Your target is the mid portion of the pterygopalatine fossa. Get an AP view and advance the needle toward the middle turbinate, stopping
when the tip is adjacent to the palatine bone. Once in the fossa, inject 0.5 to 1 ml nonionic, water soluble contrast, and observe for intravascular spread and/or intranasal placement of the needle. Once correct placement has been confirmed, inject 2 cc of local anesthetic, with or
without steroids.
SPHENOPALATINE GANGLION
After a successful diagnostic block, two therapeutic choices are available:
conventional radiofrequency lesioning (RFTC)
and pulsed electromagnetic field radiofrequency (P-EMF).
SPHENOPALATINE GANGLION BLOCKADE
RADIOFREQUENCY THERMOCOAGULATION
AND PULSED RADIOFREQUENCY
Technique
An insulated RF needle with a 3- or 5-mm active tip is
placed using the infrazygomatic approach. Once in place, sensory stimulation is performed at 50 Hz up to 1 V. If the tip of the needle is adjacent to the SPG, the patient should
perceive a paresthesia at the root of the nose at less than 0.3 V. If the paresthesia is felt in the hard palate, the needle should be redirected cephalad and medial. A paresthesia in the upper teeth indicates stimulation of the maxillary nerve
and the needle should be more caudal and medial. Motor stimulation is not necessary. After appropriate sensory stimulation, RFTC can be performed at 67 to 80° C for 90 sec
times two cycles. Before lesioning, 2 to 3 ml of local anesthetic should be injected. With P-EMF lesioning, two to four 120-sec lesions are performed at 45 V. Local anesthetic is not required for P-EMF.
SPHENOPALATINE GANGLION BLOCKADE
RADIOFREQUENCY THERMOCOAGULATION
AND PULSED RADIOFREQUENCY
COMPLICATIONS
bruising, bleeding, infection, damage to nerves, proptosis from retrobulbar hematoma,
dysesthesias, paresthesias, and/or numbness from RFTC. Bradycardia (“Konen” reflex) has been noted during RFTC and P-EMF, and can be prevented with pretreatment with
atropine or glycopyrolate
Occipital neuralgia
The term described an irritation of the greater occipital nerve (GON), and/or the lesser occipital nerve (LON). The International Headache Society defines occipital neuralgia as a paroxysmal jabbing pain in the distribution
of the greater or lesser occipital nerves or of the
third occipital nerve, sometimes accompanied by diminished sensation or dysesthesia in the affected area. It is
commonly associated with tenderness over the nerve concerned and the pain is often relieved with a local anesthetic block.
Recognized causes of occipital neuralgia
include
trauma to the greater and lesser occipital
nerves, compression of the greater and/or lesser occipital nerves or C2 and/or C3 nerve roots by degenerative
cervical spine changes, cervical disc disease, myofascial pain, referred pain from ipsilateral trigeminal distribution, and tumors involving the C2 and C3 nerve roots.
Management of occipital neuralgia
Management usually begins with conservative treatment such as physical therapy, massage, non-steroidal
anti-inflammatory drugs (NSAIDs), muscle relaxants, tricyclic antidepressants, and anticonvulsants.
When occipital
neuralgia has a structural basis then treatment is
aimed at the cause and surgery may be warranted such as
decompression or resection. Structural lesions are rare and
most patients that suffer from occipital neuralgia are usually treated with
local anesthetic blocks, botulinum toxin injections, medications, and occipital nerve stimulators.
occipital nerve block is an effective treatment for
cervicogenic headache, cluster headache, and occipital neuralgia
The cutaneous innervation of the posterior head and neck is from
the cervical spine nerves.
greater occipital nerve (GON) arises from the
dorsal ramus of the second cervical nerve and to a lesser
extent the dorsal ramus of third cervical nerve. This nerve passes between the inferior capitis oblique and semispinalis capitis muscles and ascends to pierce the semispinalis capitis and the trapezius superiorly. At this point, it travels with the occipital artery to provide cutaneous innervation to the posterior scalp as far anterior as the vertex of the skull. Medially and over the occiput, this nerve communicates
with the third occipital nerve (TON) and laterally
with the LON( lesser occipital nerve).
lesser occipital nerve LON
composed of branches from the ventral ramus of the second and third cervical nerves and ascends toward the occiput by running parallel to the posterior border of the sternocleidomastoid muscle. Near the scalp it perforates the deep fascia, and is continued
superiorly over the occiput where it supplies the skin over the posterior lateral portion of the scalp and above the ear.
third occipital nerve (TON)
The TON arises deep to the trapezius from the medial branch of the dorsal ramus of the third cervical nerve. This nerve ascends medial to the GON and is connected to it both over the occiput and as the GON rounds the inferior edge of the inferior capitis oblique.
The medial terminal
branch of the TON supplies
the skin over the rostral end of the neck and the occiput near the external occipital protuberance
OCCIPITAL NERVE BLOCK
TECHNIQUE
The patient is placed in a sitting position with the head slightly flexed downward. At the nuchal ridge a 1.5-inch, 22- or 25-gauge, B-bevel needle is inserted in the skin at the nuchal ridge and advanced until bony contact is made. The needle is then slightly withdrawn just of the bone and after negative aspiration a total of 3 to 5 ml of local anesthetic is injected. If a diagnostic block is planned a small volume should (1–1.5 ml) be used, to avoid any confusion in distinguishing greater occipital neuralgia from
myofascial pain. The LON block is performed in a similar fashion at its location
OCCIPITAL NERVE BLOCK
Landmark
The occipital protuberance, superior nuchal ridge, occipital artery, and mastoid process. The location of
the GON is typically medial to the occipital artery one third the distance between the occipital protuberance and the mastoid process on the nuchal ridge. The LON is often found two thirds the distance from the occipital protuberance and the mastoid process on the nuchal ridge. When
the occipital artery is palpated the GON should be located
just medial to the artery.
OCCIPITAL NERVE BLOCK
complication
piercing the occipital artery and bleeding. Compression of the occipital artery is usually effective in avoiding any
significant problems.
Treatment for occipital neuralgia is theorized
on the basis of
neural entrapment within the muscle
and fascia investing the suboccipital compartment and the
posterior occiput.
The traditional approach to blocking
the greater occipital nerve has been to
infiltrate local anesthetic
with or without steroid into the subcutaneous tissue around the course of the nerve after it has penetrated the trapezius muscle. The goal of infiltration at this point along the course of the nerve is the pharmacological
blockade of nociceptive transmission. This treatment is effective when the entrapment is superficial, but fails
when the entrapment occurs deeper within the suboccipital triangle.
treatment of occipital headaches treatment options
conservative medical management, physical therapy, nerve
stimulators, C2 gangliectomy, C2–C3 rhizotomy/root
decompression, radiofrequency lesioning, and sectioning of the inferior oblique muscle. procedures such as surgical decompression of the nerves in the suboccipital compartment have proven effective for longer periods of time
The suboccipital triangle
a region of the posterior cervical
neck that has the potential for neural structures to become
entrapped at multiple locations. The triangle is composed of bony articulations, ligaments, fibro-fatty tissue and bounded by three different muscles: the rectus capitis posterior major, obliquus capitis inferioris (inferior oblique), and obliquus
capitis superioris.
The suboccipital triangle content
The contents of the triangle are the suboccipital nerve, greater occipital nerve, third occipital nerve
and the vertebral artery.
The most common site of entrapment within the suboccipita triangle is
the inferior
oblique muscle and outside the triangle, the trapezius
greater occipital nerve within the suboccipital triangle
GON begins within the suboccipital triangle
and courses downward and lateral in a posterior direction at the lower edge of the inferior oblique muscle where it
bends around the muscle and ascends in a superior and medial direction above the rectus capitis toward the head of the semispinalis muscle. Here the nerves form another bend from its upward orientation in a deep to a superficial direction as it begins to move laterally. As the nerve courses upward and lateral it moves between the dorsal aspect of the semispinalis muscle and deep to the trapezius muscle. Here the nerve may pierce the semispinalis muscle or just continue upward until it pierces the trapezius muscle and travels subcutaneously
upward toward the base of the occiput.
SUBOCCIPITAL COMPARTMENT INJECTION
TECHNIQUE
The patient is placed in a prone position with the neck slightly flexed. The superior nuchal ridge is palpated and the occipital protuberance is identified. Two to three centimeters
lateral to the occipital protuberance at the nuchal ridge the skin is anesthetized with 1% lidocaine. Once
anesthetized a 22-gauge, 1.5- to 3.5- inch, sharp or blunt
Stealth™ (Epimed International) needle is advanced in a
posterior-anterior direction perpendicular to the skin toward the arch of C1. Once the needle is advanced 2 to 3 cm into the tissue a lateral view is obtained. While in the lateral view, the needle is further
advanced under live fluoroscopy toward the arch of C1. As the needle is advanced you should experience two to three distinct pops as each muscle fascial layer is penetrated. Once the needle tip is positioned at posterior arch of C1, contrast material is injected in the lateral radiographic view. The contrast spread should
be limited around the muscle layers within that enclose the
suboccipital compartment and no vascular uptake must
be noted. After successful needle position is confirmed, a total of 5 to 10 ml of local anesthetic (0.2%
Ropivacaine) and steroid (20 mg Depo-Medrol) is injected
SUBOCCIPITAL COMPARTMENT INJECTION
Complications
rare and patients may complain of
slight dizziness immediately after the procedure
The glossopharyngeal nerve course
originates from the cranial part of the medulla oblongata. Its rootlets form one root
and course forward and laterally until it reaches the jugular
foramen. As it exits the jugular foramen it joins with the vagus and spinal accessory nerve and passes between the
internal jugular vein (IJV) and the internal carotid artery (ICA). It continues to descend anterior to the ICA and dips medially behind the styloid process in close proximity to the vagus nerve, accessory nerve, and IJV emerging beneath the tip of the styloid and continuing to its
terminal branches
The glossopharyngeal nerve innervates
a mixed nerve containing sensory, motor, and autonomic
fibers. It provides sensation to the posterior one-third of
the tongue, middle ear, palatine tonsils, and mucous membranes of the mouth and pharynx above the vocal
cords. Additionally, it innervates the carotid sinus and the carotid bodies. The motor fibers innervate the stylopharyngeus
muscle and its autonomic functions are related to the parotid gland via the otic ganglion
The glossopharyngeal nerve lies in close relation to the
vagus and spinal accessory nerve. Specifically, they are in close approximation until they diverge at the midpoint of the styloid process. reported cases of GN
paroxysms with associated bradycardia and asystole
Lesions arising from the GN can send
afferent impulses via
the tractus solitarius to the dorsal motor nucleus of the vagal nerves result in reflex bradycardia or asystole
complications following blockade of the GP nerve.
a potential of pharyngeal and trapezius weakness due to unwanted blockade of the closely
situated nerves.
Blockade of the glossopharyngeal nerve several indications
used for the treatment of glossopharyngeal
neuralgia. The block can be done with local anesthetics as a diagnostic tool to determine if the patient truly has
glossopharyngeal neuralgia or it can be performed with the addition of steroids for therapeutic treatment. The procedure also can be used for surgical anesthesia or as an
adjunct to depress the gag reflex in an awake, endotracheal intubation. If a neurolytic procedure is considered, the
block can be used prior to neurolysis as a prognostic indicator.
GLOSSOPHARYNGEAL NERVE BLOCK
Extraoral Approach
Technique
Two major landmarks must first be identified: the angle of the mandible anteriorly and the mastoid process posteriorly. The patient is placed supine and the head is turned slightly opposite the direction of the affected side. Once in correct position a lateral fluoroscopic view is obtained visualizing the angle of the mandible and the mastoid process. Once identified
and marked a line is drawn between those two points inferior to the ear and the styloid process should lie midway between both points. When the target is identified a small
skin wheal with 1% lidocaine is applied to the skin and a
22-gauge, 1.5-inch needle is advanced perpendicular toward the styloid process. Bony contact is typically obtained at 3 cm. After contact, the needle is slightly withdrawn and walked off the styloid process in an anterior direction, ~ 0.5 cm. Inject 1 ml of contrast agent under continuous fluoroscopy. After injecting the contrast then 2 to 3 ml of local anesthetic (0.2% Ropivacaine) and steroid (4 mg dexamethasone) is
injected.
GLOSSOPHARYNGEAL NERVE BLOCK
Intraoral Approach
Technique
when there is an anatomic distortion externally by previous surgery or tumor. The patient is placed in a supine position with mouth wide open and the tongue is retracted
downward and medially using a tongue depressor or a laryngoscope blade. The nerve will be located at the
inferior portion of the tonsillar pillar and is accessed via
the palatoglossal fold. Once the fold is identified, a topical local anesthetic spray or pledget with 1 ml of
saline with epinephrine is applied for hemostasis. A 22-
or 25-gauge needle with a slight distal bend (25 degrees)
is advanced to a depth no more than 0.5 cm into the mucosa. After negative aspiration, 2 to 3 ml of local
anesthetic (0.2% ropivacaine) and steroid (4 mg of
dexamethasone) are injected.
GLOSSOPHARYNGEAL NERVE BLOCK
COMPLICATIONS
The extraoral approach
lead to complications secondary to the close proximity of relation of the CN IX, CN X, CN XI,
and CN XII at the styloid process. There can be accidental puncture of the vessels leading to vessel trauma and
hematoma formation. Also inadvertent intravascular injection of the ICA or IJV may lead to seizures or even
cardiovascular collapse
GLOSSOPHARYNGEAL NERVE BLOCK
COMPLICATIONS
The intraoral approach
With the intraoral approach there
is a potential of vessel trauma and neurotoxicity but much
less that the extraoral approach. Other complications
can occur with unwanted blockade of CN X, CN XI, and
CN XII.
Blockade of the vagus can lead to
bradycardia, asystole, reflex tachycardia, and syncope, as well as dysphonia secondary to ipsilateral vocal cord paralysis
Blockade of CNXI and CNII can result
in temporary weakness of the trapezius muscle and the tongue
The cervical plexus block is performed for
anesthesia and
analgesia involving the head and neck region
The cervical
plexus is formed by
the anterior divisions of the first four upper cervical nerves (C1–C4) and the lower four nerves (C5–C8) together with the first thoracic ventral ramus
(T1) form the brachial plexus.
The location of the cervical plexus lies
deep to the internal jugular vein upon the
levator scapulae, scalene muscles and underneath the sternocleidomastoid muscle.
cervical plexus is divided two separate rami each dividing into
an ascending (superficial cervical plexus) and descending (deep cervical plexus) branch forming loops at each level with the corresponding nerves except for the first ramus.
The first cervical ramus
suboccipital nerve
primarily a motor
nerve. Even though it lacks cutaneous innervation it does
have some sensory function and communicates sensory
information to deeper muscles in the suboccipital region as
the suboccipital nerve.
The C1 nerve is often not affected
by a cervical plexus block due to
its posterior and deeper
location.
The second, third, and fourth cervical nerves
leave their respective transverse processes
anteriorly and
surface lateral to the vertebral artery. The C2 and C3 nerves continue on and emerge at the midpoint of the posterior
border of the SCM muscle and travel
toward to their destination
The C2 nerve moves upward along
the sternocleidomastoid toward the posterior and lateral part of the scalp.
C2 nerve provides cutaneous innervation
to the
posterior scalp behind the ear, the upper and posterior auricle as well as the mastoid and angle of the mandible as the lesser occipital and great auricular nerve.
The C3 nerve bifurcates into
an anterior and descending portion. The anterior branch runs in an anterior oblique
direction where it gives cutaneous innervation to the lateral neck from the chin to the sternum as the transverse
cervicalis. The descending branch continues along the SCM muscle into the posterior triangle
of the neck beneath the platysma and deep cervical fascia and joins the fourth cervical nerve. Here these
nerves provide cutaneous innervation to the upper trapezius,
shoulder and pectoral region as the supraclavicular
nerves.
The deep branches of the cervical plexus divide into
medial and lateral branches. The medial branches supply the anterior and lateral neck muscles and gives rise to the phrenic nerve via the fourth cervical nerve as the main
contributor. The lateral deep branch forms communicating
branches between C1 and C2 rami to the vagus and hypoglossal nerves.
the deep cervical plexus
gives rise to several muscular branches. These branches
supply the
rectus capitus lateralis (C1), rectus capitus anterior (C1, C2), longus capitus (C1–C3), and longus colli
(C2–C4). The muscular
branches are distributed to the SCM
(C2–C4), trapezius (C2, C3), levator scapulae (C3, C4) and scalene medius (C3, C4)
deep branches of the cervical plexus lateral branches communicate with the
spinal accessory nerve and supply the deep surface of
the trapezius via the communicating branches.
CERVICAL PLEXUS BLOCK
INDICATIONS
a safe alternative to general anesthesia for procedures involving the anterior-lateral portion of the neck, upper shoulder, and posterior scalp. Its potential indications
are many and include superficial neck procedures, neck
dissection, thyroglossal and brachial cyst surgery, thyroidectomy,
lymph node dissection, cervical node biopsy,
carotid endarterectomy, and other head and neck neuralgias.
CERVICAL PLEXUS BLOCK
motor and sensory
blockade
The sensory and motor component of the cervical plexus can each be blocked separately or together. A deep cervical plexus block provides motor and sensory blockade while a superficial plexus block only blocks the sensory component of the plexus.
The blockade of the
superficial cervical plexus provides anesthesia and analgesia for
the posterior and anterior auricular scalp region, lateral and anterior neck, and the upper shoulder region
The superficial cervical plexus block is useful for
postoperative
pain relief; reduce nausea and vomiting with surgeries involving the tympanic-mastoid region, and for
simple superficial procedures such as involved with plastics
or superficial biopsies involving the neck. Additionally, this block is sometimes performed for carotid endarterectomy
and thyroid surgery.
The branches blocked by the
superficial cervical plexus block include
the lesser occipital,
great auricular, transverse cervicalis and the supraclavicular
nerves. For blockade of the deeper structures and the motor components a deep cervical plexus block is
warranted
Blockade of the deep cervical plexus provides anesthesia and analgesia of the
superficial and the deeper muscles
within the anterior and lateral neck up to the upper shoulder region.
Blockade of the deep cervical plexus indications
This technique can be used for surgical
anesthesia, post operative pain relief and diagnosis and
treatment of painful conditions involving the neck, posterior
scalp, and upper shoulder region. This block is performed
for procedures such as thyroidectomy, tracheostomy, and laceration repairs under local anesthesia or any
procedure that require muscle relaxation of the neck. One of the most common indications is for awake carotid
endarterectomy
One of the more uncommon indications is for Blockade of the deep cervical plexus
the treatment of intractable hiccups as the deep branches
innervate the muscle of the diaphragm
Superficial Cervical Plexus Block
TECHNIQUE
The patient is placed
in a supine position with the head turned away from the side that is going to be blocked. Once in correct position, it is important to identify the posterior border of the SCM muscle. This can be done one of two
ways. Two landmarks must be identified; the mastoid process and Chassaignac’s tubercle at C6. A line is drawn
from the mastoid process to Chassaignac’s tubercle over the SCM muscle. The drawn line should overly the path of the superficial cervical plexus over the posterior border of the SCM muscle. The position of
needle entry will be at the midpoint of line drawn from the mastoid process to Chassaignac’s tubercle. This is the site where the branches superficial plexus appear behind the posterior boundary of the SCM muscle. A 22- or 25-gauge, 4- to 5-cm needle is inserted subcutaneously 2 to 3 cm deep at the midpoint of the posterior border of the SCM muscle and
3 to 5 ml of local anesthetic is injected. The needle is then withdrawn and redirected subcutaneously in a superior direction toward the mastoid process while injecting
3 to 5 ml of local anesthetic in a fan-like fashion. The needle is then redirected in an inferior direction subcutaneously
toward Chassaignac’s tubercle injecting 3 to 5 ml of local anesthetic in a fan-like fashion
Deep Cervical Plexus Block:
target
landmarks
the transverse
processes of C2 to C4 will be targeted. The patient
is placed in a supine position with the head turned away
from the side that is going to be blocked. Once in correct
position, two landmarks are identified; the mastoid process
and Chassaignac’s tubercle at C6
Deep Cervical Plexus Block:
IDENTIFICATION OF NERVES
A line is drawn from the mastoid process to chassaignac’s tubercle
overlying the SCM muscle. Once the SCM
is identified then the transverse processes
of C2, C3, C4, and C6 must be identified. This is achieved by first identifying the cricoid cartilage. Once identified, a line is drawn from the inferior aspect of the cricoid to the SCM. The point where these two lines intersect at a right angle is the C6 transverse process. Next the thyroid notch and superior cornu is palpated. Once located, a line is drawn to the SCM, and the
transverse process of C4 is identified at the point where the two lines intersect. Once the C4 transverse process is located, the transverse processes of C2 and C3 can be
easily identified. This is done by taking half the distance between C4 and C6. This measurement will be the distance between the transverse processes at each level. Once the intertransverse process distances are determined it is plotted along the original line drawn from the mastoid to Chassaignac’s tubercle. Beginning at the C4 transverse
process the distance is plotted upward toward the mastoid process and it should identify the C3 transverse process. The same distance is plotted from C3 to the mastoid and
the C2 transverse process will be identified
Deep Cervical Plexus Block:
TECHNIQUE
After drawing out the points of interest the neck is prepped, cleaned, and draped in sterile fashion. The block is performed by using a 22-gauge, 1.5-inch needle, the transverse processes are located by entering
the skin in a perpendicular fashion. The needle is always
directed in a medial caudal direction to avoid any unintentional
vertebral artery, epidural, subdural, or spinal injection.
The needle is advanced slowly until the transverse process is contacted, which is typically 1.5 to 2.5 cm. the needle should
be redirected slightly posteriorly as the spinal nerves are located just in front of the transverse process. When bony contact is made, withdraw the needle 1 cm and
after negative aspiration, 3 to 5 ml of local anesthetic is
injected slowly. The needle is then removed and the entire procedure is repeated at the other two transverse processes
Cervical Plexus Block:
CHOICE OF LOCAL ANESTHETICS
For shorter duration procedures 2% lidocaine and mepivacaine may be desired as this may achieve blockade up to 4 hr. For longer procedures ropivacaine or
bupivacaine can be used and this may prolong the block
up to 8 hr. Higher concentrations of local anesthetic will also prevent required supplemental infiltrations from the
surgeon. Lidocaine will
have faster onset times than mepivacaine, ropivacaine and
bupivacaine
Cervical Plexus Block:
DOSING
A total amount of 0.4 or 0.5 ml/kg (30 ml) is usually considered sufficient to perform either the superficial, deep or a combination of both blocks.
Furthermore, toxicity and systemic absorption can be
decreased with the addition of epinephrine to the local anesthetics. Epinephrine will decrease systemic absorption of bupivacaine and lidocaine by 20% or more.
adjunct used with local anesthetic
Clonidine
complications can occur when performing a cervical plexus block
always a risk of infection, risk of hematoma, Local anesthetic toxicity, Intravascular injection (vertebral or carotid artery), Nerve injury. Temporary diaphragmatic paresis invariably will occur
with the deep cervical plexus block. The blockade of the phrenic nerve cannot be avoided with this block. For that reason this procedure should never be performed in a bilateral fashion. The superficial plexus block will not cause blockade of the phrenic nerve. a high spinal (Avoid inserting the needle to deep as there is a
possibilty of a cervical cord or intrathecal injection.)
Intravascular
injection of local anesthetics can lead to
central nervous
system (CNS) or cardiac side effects. The CNS effects can
vary and will most likely consist of perioral numbness, sedation, tinnitus, or even seizures. Cardiac effects can
occur but usually happen with higher blood levels of local
anesthetics.
if you experience high resistance with injection. This may indicate that the needle has been placed into
the nerve or nerve sheath and injection of
local anesthetics may lead to nerve ischemia and permanent
damage.
The injection of local anesthetics within the dural sleeves
around the nerves can cause
some of the volume to back track into the epidural space and even the subarachnoid
space leading to a high spinal. This will present as hypotension
and loss of consciousness. Treatment will involve
airway control and cardiovascular support until the local
anesthetic is metabolized from the CNS.
