Cervical Injection Techniques and Sphenopalatine Ganglion Block (SPG)Chris Zarembinski, M.DCedars-Sinai HospitalLos Angeles, CA

Why Perform Diagnostic Injections?Once the precise pain generator is known, diagnosis specific care can be provided to optimize outcome.

Cervicogenic Headache

Prevalence of cervicogenic headache among the headache population has been reported at 13.8 to 35.4%.54% of whiplash patients had neck pain from a cervical zygapophysial joint.Lord J Neurol Nurosurg Psychiatry 1994; 57:1187-1190.

Cervicogenic HeadachePain located over low occipital and temporal region and can radiate periorbitally.Can be induced with neck movements.Predominantly female.Older than migrainous headache (49.5 years v 34.7 years.Only structures innervated by the first three cervical nerve roots (C1-C3) are capable of causing headache.

Upper three cervical nerves and the trigeminal nerve ramify in gray matter formed by the pars caudalis of the spinal nucleus of the trigeminal nerve. The region of gray matter is considered a combined nucleus “trigeminocervical nucleus.”Bogduk Neural Blockade J.B. Lippincott, 1988.

Cervicogenic HeadacheNo disc below C4-5 ever referred pain to the head (Slipman Pain Physician 2001; 4:167-174.)Medial br of dorsal ramus of C2 becomes the greater occipital n, while the lesser occipital nerves arises from ventral rami of C2 and C3.

Whiplash InjuriesRear end collisions are responsible for 85% of all whiplash injuries. 82% of whiplash injuries in auto not towed, v 66% when auto towed.73% patients wearing seatbelt develop neck pain, as compared to 53% not wearing seatbelts.

Areas of InjuryThe rapid motion of the neck during a crash can result in a variety of injuries - many of which are not seen on x-rays or MRI. The most common lesions affecting the cervical spine following whiplash are:Disc LesionsEndplate avulsionsTears of the anterior longitudinal ligamentUncinate process fractureArticular subchondral fractures Articular pillar contusionArticular process avulsionLigament TearEsophageal perforation

Motion During a Collision0 millisecondsAt the moment of impact, the car seat just begins to move and the occupant has not yet been accelerated forward.

Motion During a Collision50 millisecondsAs the car seatback pushes the torso forward, the spine moves forward, resulting in a straightening of the thoracic and cervical spine.Head remains stationarySeatback pushes torso forward

Motion During a CollisionThis difference in motion between the neck and torso results in a pathological S-shaped curve. This rapid, abnormal bending can result in damage to the posterior spinal joints (facet joints).75 millisecondsAt this point in the collision, the car seat is rapidly pushing the occupant's torso forward, while the head remains stationary due to inertia.Head remains stationarySeatback pushes torso forward

Motion During a Collision150 millisecondsThe torso has pulled so far forward on the lower neck that the head is forced backwards. Depending on the severity of the collision, the front portion of the spine (intervertebral discs) can be injured during this phase of the collision.Head rotates backSeatback pushes torso forward

Motion During a Collision200 millisecondsFinally, the head and torso are thrown forward by the force of the car seat.Head thrown forwardForce from car seat

AO and AA joints

AO and AA joints are in series with the small uncovertebral joints on the sides of the bodies of the cervical vertebrae, not with the z-joints. They are positioned anterolateral to the spinal canal and cord.McCormick J Interventional Radiol 2:9-13, 1987.

AO JointInnervation from ventral rami of C1.Bean-like appearance.Large joint as compared to lower cervical z-joints.Allows for 20 degrees of extension.Posteriorly, the vertebral art is farthest from the joint at the most superior and lateral margin of the joint.Pain may spread to frontal area slightly anterior to vertex.C-arm obliqued 25 to 30 degrees ipsilateral.Joint volume is 1 – 1.5 ml.

densC1-2Ipsilateralobliqueright

densC1-2occiputContralateraloblique

C1densocciputLateralimaging

AA JointLong axis is oriented obliquely.Joint innervation is from the ventral rami of C2.Articular surface of the axis is convex.Allows 40 degrees of rotation to either side of midline.Pain is localized to sub-occipital, postauricular level.

densC1-2right

DensC1-2joint

Facet Joint (z-joint)

What is the diagnostic importance of z-joint injection?Radiographs, history, and physical exam are not specific for cervical, thoracic, or lumbar z-joint mediated pain.

Cervical Z-joint PainKnown pain source; referral maps existInnervation is from the medial branch (MB) division of the dorsal rami corresponding to the joint level (e.g. C5-6 from C5 and C6 MB nerves); C2-3 innervated by the third occipital nerve (TON) and a contributing inferior branch from C2

In whiplash-injured patients in whom headache was the main complaint, the headache was related to the C2-3 joint in 53% of cases.Lord Clin J Pain 11:208-213, 1995.

Referred Pain Patterns"... the prevalence of cervical zygapophysial joint pain was 60%."The most common facets to be injured were at C2/C3 and C5/C6.Wallis BJ, Lord SM, Bogduk N. Resolution of psychological distress of whiplash patients following treatment by radiofrequency neurotomy: a randomised, double-blind, placebo-controlled trial. Pain 1997;73:15-22.C2-3C4-5C6-7C3-4C5-6C6-7

Patient Selection-Facet JointEvaluation of sites of maximal segmental or direct articular tenderness.Evaluation of articular restriction co-existing with localized soft tissue findings such as increased muscle tone.Recognition that the most commonly involved joints are C2-3, C5-6, C6-7.Evaluation of recognized z-joint referral zones.Fukui, Pain 68:79-83, 1996.

C3-4

Pillar view imaging

Ultrasound-guided facet joint injections in the middle to lower cervical spineNeedles were advanced strictly in parallel to long axis of the ultrasound transducer to keep them in the echo plane.Handling of the transducer was critical to achieve good visualization of the entire needle, realizing that ultrasound beam is only millimeters thick.Galiano, K. Clin J Pain. 22(6) 538-543. July/August 2006.

Posterior Column GuidelinesIn general, no more than 2 z-jt injections/year and only if sustained relief occursNo place for a series of z-jt injectionsAfter z-jt injections one usually follows with conservative care options (e.g. PT).

Posterior Column GuidelinesDual blocks needed for a more secure diagnosis (decrease false positive rate)80% plus relief confirms the z-jt as the pain generator and best selects those for MB RF neurotomyEvaluate the AO/AA joints separately from the z-joints

Cervical Selective Nerve Root Block

Risks and Complications

DRGSAP

DRGcordSAPDISCSPACE

Risks and ComplicationsThere have been case reports of cerebellar infarct, spinal cord infarct, epidural hematomas, transient quadriplegia, and death.30% incidence of vascular penetration was noted during cervical block procedures performed blind (Davies Reg Anesth 1997; 22:442-446).

Risks and ComplicationsFurman showed during the performance of 504 procedures that the visualization of blood was insensitive of intravascular tip placement (45.9%).Spine 2003; 28:21-25.

44 y.o. woman after right C7 SNRB under fluoro guidance, immediately became unresponsive and required CPR. Procedure was completed with 25 g 3.5 inch needle from oblique lateral approach. Type of steroid used was not reported. Wallace M. Am J Roentgenology; 188:1218-1221 2007.

On admission, pupils were nonreacitve and had no corneal or gag reflex. Pronounced dead after within 24 hr from procedure. Autopsy revealed massive cerebral edema with dissection of the vertebral artery extending into basilar artery with thrombus within vertebral artery.Wallace M. Am J Roentgenology; 188:1218-1221 2007.

CT scan shows edema of brainstem, pons, midbrain.

41 y.o. male became acutely confused and showed left sided upper extremity weakness while undergoing a left C5 SNRB under fluoro guidance. Type of steroid used was not reported. Wallace M. Am J Roentgenology; 188:1218-1221 2007.

CT showed contrast material within wall of left vertebral art extending from C3 to C6.

Left vertebral arteriogram showed irregularity of left vertebral art consistent with dissection.

Patient was heparinized. CT of the head was normal. Presenting symptoms of confusion, visual deficits, upper extremity paresis and facial weakness resolved with 24 hr.Author concluded that use of contrast material during fluoro to determine vascular placement, would not prevent arterial dissection.Author also noted no studies provided yet to compare the complication rates of fluoro versus CT guided cervical SNRB.

Cerebellar infarct after particulate corticosteroid injection of C5-6 SNRB.Patient was post MVA and was 5ft 2 inches and weighed 300 lb.Corticosteroid was mixed with local anesthetic.Presumed vertebral artery injection.Tiso, et. al. Spine Journal 4 (2004) 468-474.

Recommendations from Tiso’s Study:Use test dose of local anesthetic prior to corticosteroid injection.Use microbore extension tubing (i.e. “pig tail”) to minimize needle manipulation.Minimize sedation to allow earlier detection of CNS dysfunction.Needle tip should be in posterior aspect of foramen.

Size Aggregation and Particulate Density of Corticosteroid Preparation in relation to size of Red Blood CellsRed blood cell diameter: 7.5-7.8 um.Methylprednisolone - uniform in size, most smaller than RBC, propensity to pack densely.Betamethasone – rod shaped, variable size, densely packed particles, extensive aggregations > 100um, 12x greater than size of RBC.Triamcinolone – variable size 0.5 um to larger than 100 um, densely packed, extensive aggregation.Dexamethasone - 0.5 um size, smaller than RBC, no apparent aggregation.

Methylprednisolone (Depo-Medrol)

Betamethasone (Celestone)

Triamcinolone (Kenalog)

Dexamethasone (Decadron)

Spinal Cord/Brain InfarctionMethylprednisolone (Depomedrol) 3 cases.Betamethasone (Celestone) 2 cases.Triamcinolone (Kenalog) 3 cases.Dexamethasone (Decadron) 0 cases.

12.5 mg Decadron v. 60 mg Triamcinolone, in single injection, randomized study.Dreyfuss, P. International Spine Intervention Society, 14th Annual Scientific Meeting, July, 2006.Comparative effectiveness of cervical transforaminal injections with particulate and non-particulate corticosteroid preparations for cervical radicular pain

ResultsNo significant difference in pain relief between Decadron and Triamcinolone.65% improvement in VAS at four week follow-up noted with both groups.Study limited by small sample size and follow-up time.

Anatomic Considerations

Beware of Anomalous AnatomyDegenerative arthritic changes and disc space narrowing in the cervical spine affect the course of the vertebral artery. The vertebral artery has even migrated into the vertebral body. Curylo, L. Spine 2000; 25:2860-4.

Anatomy of the cervical intervertebral foramina: vulnerable arteries with potential for ischemic neurologic injuries after transforaminal epidural injections.Huntoon, M. Pain 117 (2005) 104-111.

Ascending Cervical ArteryTypically derived from the inferior thyroid or thyrocervical trunk. Occasionally came directly from the subclavian artery.Ascended on the anterior tubercles of the transverse processes and ascended parallel to the more lateral phrenic nerve.Supplied a spinal branch at the C3-4 or C4-5 neural foramen at the posterior/inferior aspect of the external foraminal opening.

Deep Cervical ArteryLarger in diameter than the ascending cervical arteries.Arose from the costocervical trunk or occasionally directly from the subclavian artery.Spinal branches always entered at either C5-6, C6-7, or C7-T1 level.Classic location is between the semispinalis capitis and cervicis muscles.

Semispinalis cervicisSemispinalis capitisDeep cervical artery

Author’s ConclusionsConventional fluoro and CT cannot consistently demonstrate radicular or segmental vessels.Consider digital subtraction radiography.Deep cervical and ascending cervical arteries were more vulnerable to cannulation if needle not sufficiently advanced into foramen.

International Spine Intervention Society (ISIS) Technique for Cervical SNRB

Outcome Studies

Haueisen:Clin Orthop Rel Res;198:179, 1985Haueisen retrospectively assessed emg, and myelography in 55 patients against a positive nerve root block (concordant symptoms production, full relief, loss of neural tension signs).

Haueisen:Clin Orthop Rel Res;198:179,1985Myelography accurately revealed the surgical lesion in 24%.Electromyography accurately revealed the surgical lesion in 38%.Selective nerve root block correlated with the surgical lesion in 93%.

Anderberg Eur Spine J. 2006 Jun:15(6): 794-801The degree of MRI pathology, neurological assessment, and pain distribution in the arm were not reliable parameters enough when deciding the affected nerve root in patients with cervical radiculopathy and two-level degenerative disease.Cervical SNRB was found helpful when evaluating two or more levels of degeneration presenting with radicular pain.

Derby, Spine 1992;17(6S):S176-S183.Injection of steroids during selective nerve root block had good negative predictive value. Patients with more that 1 year of radicular pain who did not have a long-term response to a snrb had a poor surgical outcome.

Conclusions-SNRBUse with patients with radicular pain or radiculopathy. Help evaluate patients when mulitlevel imaging abnormalities present to more accurately define the levels for surgery.Use in postop patients with complex recurring pain.Use to evaluate patients with equivocal neurologic exam.

Cervical Discography

DiscographyHistory and physical exam are unreliable in diagnosing discogenic pain.Patient with elevated scores on hypochondriasis, hysteria, and depression scales of the Minnesota Multiphasic Personality Inventory tend to over report pain. Discordant pain response in such cases should be cautiously interpreted even with concordant imaging.(Block, Spine 21:334-338, 1996).

Cervical DiscographyProvocative test to determine if the disc is a pain source; not just an imaging test.Largely a pre-surgical tool for ACFsOnly test available to assess the pain status of the disc’s interior.Contraindicated in central stenosis, myelopathy, neoplasm, infections.

Mercer, Bogduk. Spine 24:619-628, 1999 59 discs in 12 specimens dissectedfcanteriorposterior

Cervical DiscographyDisc volume is small (0.1-0.3 cc)A right anterolateral appoach with the carotid artery displaced laterally and esophagus displaced medially can be used.Oblique approach with foraminal view can also be used, needle placed just anterior to the UV joint; needle pass is anterior to the vertebral artery and lateral to the CCA and esophagus.

Grubb, Kelly.Spine 25:1382-1389, 2000173 discograms404 positivediscs>50% with >3 positive discsC2-3C3-4C4-5C5-6C6-7

Discography-patient selectionDiscogenic pain suspected (loading intolerance, nonnradicular pain, no nerve root distribution weakness, no reflex abnormality).Facetogenic, neoplastic, inflammatory, and traumatic pain have been excluded.No signs of pain caused by compression of neural elements present (e.g. herniation, osteophytes, synovial cyst).

Patient Selection-DiscographyTo assess for possible spinal fusion and evaluate adjacent levels.To assess for symptomatic levels in patients with minimal findings on MRI/CT.Test of exclusion when other minimally invasive therapies have failed.

RightLeft

NormalCervicalDiscogram

CervicalDiscographyOblique Approach

2 weeks post discogram with gadolinium

Cervical DiscographyGreatest risk is infection (0.1-0.2% from anterior approach).The best discogram is a negative one; a control (asymtomatic) level should be obtained (if possible).Recommend at least 3 levels routinely be performed due to the high incidence of multiple positive levels.

Sphenopalatine Ganglion

Sphenopalatine Ganglion Block for Traumatic Trigeminal NeuralgiaChris Zarembinski, M.D.Steven Graff-Radford, D.D.S.The Pain CenterCedars-Sinai HospitalLos Angeles, CA

Continuous Neuralgias of the FaceSignificant number follow dental or surgical therapies.A lesion must be present in the trigeminal distribution to cause a continuous neuralgia.Often described as a burning numbness.Most cases in females in their 4th decade.These findings define Trigeminal Dyesesthesia (TD).

Mechanisms of InjuryPeripheral sensitization.Ectopic activity due to sodium channel expression.Central sensitization.Beta fiber reorganization.Alteration in central inhibition systems.Pathological adrenergic coupling between sympathetic postganglionic fibers and afferent neurons forms the basis of sympathetic block in continuous neuralgias.

Sphenopalatine Ganglion-Anatomy

Sphenopalatine Ganglion-Parasympathetic FibersParasympathetic fibers emerge from brainstem as part of nervus intermedius of the facial nerve and forms greater petrosal nerve. Postganglionic fibers distribute to lacrimal gland, nasal cavity, pharynx, major cerebral arteries and stimulation may increase cerebral blood flow.Parasympathetic vasodilator fibers innervate palate and participate in reflex vasodilator response to painful tooth-pulp stimulation.

Sphenopalatine Ganglion-Sympathetic FibersSympathetic fibers in SPG are post-ganglionic fibers which have already synapsed in the superior cervical ganglion. Reach SPG via the internal carotid plexus and deep petrosal n and pass through without synapsing with branches of the maxillary nerve.Sympathetic fibers of SPG are a subset of those blocked by stellate block. Horner’s syndrome would not be expected because sympathetic innervation to the pupil and eyelid would not be affected.

Sphenopalatine Ganglion-Sensory FibersMaxillary division of trigeminal nerve enters SPG fossa through foramen rotundum and is entirely sensory serving the mid-face.Branches serve the palate, nasal cavity, and upper pharynx.

J. Neurosurg. 106:157-163, 2007

Sphenopalatine Ganglion Block v Stellate Ganglion Block for Continuous Neuralgia of the FaceObjectives—Neuropathic trigeminal pain has responded to sympathetic block. Long term response to stellate block is inconsistent. Sphenopalatine block (SPG) may offer a better outcome in continuous neuralgias because of the specificity to the face and targeting of parasympathetic and sensory fibers.

Conclusions-Sphenopalatine Ganglion (SPG)Sphenopalatine ganglion (SPG) block provides as much relief, if not better, for traumatic trigeminal neuralgia as compared to stellate ganglion block.The SPG block is more specific to the head and face, as compared to stellate block.The SPG block affects parasympathetic, sympathetic, and sensory fibers, having potentially a much broader effect on facial pain complaints than stellate block.Patient satisfaction of SPG was 30-40% better than stellate with avoidance of Horner’s syndrome.SPG facilitates radiosurgery applications for more permanent solutions.

Rationale for Radiosurgery of the Sphenopalatine Ganglion for Facial PainUnpredictable response to percutaneous radiofrequency denervation of the sphenopalatine ganglion and stellate ganglion with benefit short-lived under four months.

Axial Image

Coronal SaggitalTwo superimposed 8 mm ports

Radiosurgical Ablation of Sphenopalatine GanglionMethods: 90 Gy delivered through two 8 mm superimposed ports with Gamma knife.6 Month Results:11 patients treated.9 out of 11 had more than 60% reduction in pain.1 patient had recurrence of pain after 3 months.Conclusions: Patients who respond to two SPG blocks have a favorable outcome to radiosurgery ablation.