Al-Azhar Med. J. Vol. 46(2), April, 2017, 383-390 DOI: 10.12816/0038261 PRIMARY EXPERIENCE WITH CT GUIDED MANDIBULAR BLOCK IN PATIENTS WITH TRIGEMINAL NEURALGIA

By

Samy M Abdelraouf *, Ashraf M Enite and Ola I Saleh

Departments of Neurosurgery* and Radiodiagnosis, Al-Azhar Faculty of Medicine (Girls)

ABSTRACT Background: Trigeminal neuralgia (TN) is a well-known facial pain syndrome characterized by excruciating paroxysmal shock pain attacks located in somato-sensensory distribution of trigeminal nerve. Mandibular affection is a common presentation of TN. Objectives: Studying the effect of injection of mandibular nerve with neurolytic solutions in trigeminal neuralgia that was unresponsive to pharmacotherapy. Patients and Method: This prospective study included 21 patients treated for mandibular neuralgia by percutaneous injection of absolute alcohol under guidance of CT image. Their ages ranged from 35-60 years and male to female was 3:4. All patients suffered from moderate to severe TN, and did not respond to medical treatment. Entry and trajectory of needle was planned by CT and after local anesthesia. Alcohol was injected at the exit of mandibular nerve from foramen ovale. Results: 85.7% of patients improved (71.4% became pain free and severity of pain decreased in 19%), while 9.6% of patients has no response after injection. The pain free patients became 61.9% after two years of follow up. Conclusion: CT guided mandibular by neurolytic agent as absolute alcohol and showed its effectiveness as minimal invasive treatment option for intractable trigeminal neuralgia. CT guidance provided a clear view to secure the safety, accuracy and selectivity of nerve block. Key words: Trigeminal neuralgia, computed tomography guided, nerve block. Abbreviations: BNI-PS= Barrow neurological institute pain scale, CT= computed tomography, HIV= human immunodeficiency virus, MRI= magnetic resonant image, MVD= microvascular decompression, RF= radiofrequency, TN= trigeminal neuralgia, TNB= trigeminal nerve block, VAS= visual analogue scale.

INTRODUCTION Nerve blocks are an optional method Trigeminal neuralgia is a paroxysmal for relief of severe pain. Although lancinating pain lasting a few seconds, analgesic may reduce the pain, nerve often triggered by sensory stimuli block can completely stop pain. In confined to the distribution of one or more general, two types of nerve blocks are branches of trigeminal nerve on one side used, i.e. local anesthetic injection and of the face with no neurological deficit neuro-destructive methods. Because of (Greenberg, 2016). short duration of action of local anesthetic agents, it can be used to protect against

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acute incidental pain and for diagnostic where 0 = no pain and 10 = the worst pain tests. Neuro-destructive blocks use imaginable. Our patients ranged from neurolytic agents as alcohol, phenol, moderate to severe pain. All of them did glycerol or radiofrequency thermo not respond to medical treatment. Pain coagulation for intractable pain (Curatolo chronicity and frequency varied from 3 and Bogduk, 2010). per day to 10 per hours. Pain triggers and TNB should be guided by radiological zone which was present in one half of the imaging as X-ray fluoroscopy or CT. X- patients, and often lied near the nose or ray fluoroscopy is the most commonly mouth. Chewing, talking, smiling and used form of image guidance in drinking cold or fluid may initiate the pain interventional pain therapy. It gives wide of TN. Assessment of muscles of field of view around target region and mastication was important (which continuous real time view when needed. supplied by mandibular nerve). In addition, the apparatus is not Examination was done for reflexes excessively expensive. The limitation to supplied by trigeminal nerve (absent fluoroscopy, however, is that it shows corneal reflex was the earliest sign of TN only bones. Therefore, it is suitable only when ophthalmic branch was affected). for target nerve with a dependable All patients underwent to MRI brain to relationship to bony landmark. Also, it exclude organic cause of TN. Laboratory gives only two dimensions picture, and its investigations as complete blood count, quality is not accurate as it with CT. CT bleeding time, coagulation profile, provides clear view vessels that should be hepatitis markers and HIV antibodies avoided by needle in addition to avoiding were done for all patients. inadvertent puncture of vital structure. It Inclusion criteria: allows accurate placement needle tip before injection of neurolytic agent with 1. Age 18-60 years old. clear view of muscle and soft tissues 2. Males and non-pregnant or lactating (Koizuka et al., 2014). females. PATIENTS AND METHODS 3. Subjects have mean attacks frequency of at least 3 episodes per day and VAS This study was completed at Al-Zahraʼa ≥ 5. University Hospital between August 2013 and September 2014 after the approval of 4. Diagnosis of classical TN using inter- the hospital local health committee and national classification of headache written informed consents were obtained. disorders (ICHD-II). Twenty one patients of different ages 5. Subjects on stable dose of concomitant ranging from 35-60 years were included in preventive medication for treatment of this work. They suffered from TN along TN for at least four weeks prior to mandibular branch distribution. All intervention. patients were evaluated regarding history, pain localization which was confirmed to 6. Subjects who required "rescue" analgesic mandibular nerve, severity of pain medication during study were allowed to use their current (pre-study) opioid evaluated by visual analogue scale (VAS),

385 PRIMARY EXPERIENCE WITH CT GUIDED MANDIBULAR NERVE BLOCK...

and/or non-opioid analgesic as the target position by clear CT image, and clinically indicated, e.g. NSAIDs and confirmed by injection of 0.5 ml of 10% topical analgesics. diluted iodine contrast material. We used 7. Subjects were prohibited, willing and Iopamidol (Io-pamiro 300, 300 mg of able to abstain from initiating and iodine/ml; Bracoo Diagnostic Princeion, alternative therapy, e.g. acupuncture, Newjersy, USA). Also, mandibular massage or physical therapy, for pain paresthesia can be elicited by injection of relief during the study. 0.2-0.3 ml of lidocaine 1%. A series of CT scan slides were done immediately to Exclusion criteria: confirm the needle tip position. The 1. Symptomatic TN. needle tip was then walked carefully into the foramen ovale. A negative test for 2. Serious hepatic, respiratory, hemato- CSF and blood aspiration was proved, a logic, cardiovascular or renal condi- 0.1 to 0.2 ml increment of dehydrated tions. absolute ethanol were injected every 30 3. Neurologic pain other than TN except seconds up to 1 ml. for occasional migraine or tension Patient reported outcome scales (PRO): headache (<4 headaches per month). The visual analogue scale (VAS) and 4. Psychiatric or medical condition that Barrow Neurological Institute pain scale might compromise participation in (BNI-ps) were the 2 PRO measures used study as determined by investigator. in this study. VAS provided an estimate of 5. Administration of any interventional pain intensity on a continuous scale, with drug within month prior to screening. a score 0 representing no pain and a score 10 representing worst pain. The BNI-ps 6. Substance abuse or alcoholism. rates pain on a scale of 1 to 5, Technique: All patients were monitored incorporating degree of dependence on with continous electrocardiogram (ECG), medication, as a score 1 representing no pulse monitoring and intermittent pain and no medication, while a score 5 noninvasive blood pressure. An representing sever pain or no pain relief intravenous line was inserted. 1 to 5 mg (John, 2016). I.V. midazolam, 25-50 mg fentanyl were After the procedure, patient was given to produce slight sedation and observed in recovery room, or short stay analgesia during the procedure. The block unit for 1-2 hours depending on the was performed with the patient in supine patient condition. All patients were position on CT table, and skin disinfection clinically evaluated before and after was done by betadine (bovidone iodine) injection at 1 to 3 days, 2 weeks and 6 solution. Under local anesthesia, 2-3 ml of months by using VAS and BNI -ps. 1% lidocaine, using the standard anatomical landmark and under CT Trigeminal sensory function was guidance, 22 gauge, 3.5 inches, 0.7 × 90 evaluated on the pain side and mm pd spinal needle was inserted to reach contralaterally by testing for light touch the foramen ovale at the base of skull. We and pin prick. The response was ranked should be sure that the needle tip was at according to four grade scale (normal,

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slightly decreased, severely decreased and Values of P < 0.05 were considered totally impaired). significant. In pain free patients, a further follow RESULTS up was conducted by telephone and in Twenty one patients who fulfilled pain persistent patients. Repeated inclusion criteria were studied, male to injection was done or referral to other female was 3:4, and their ages ranged option of management in more resistant from 35 to 60 years. They presented by cases. A pain free condition was defined moderate to severe pain along the as, the patient being completely free from distribution of mandibular nerve (Table trigeminal pain without medication. 1). Statistical analysis: Kaplan-Meier Adequate pain relief was obtained in analysis was used to construct pain free eighteen of them, and they stopped or survival curves for censored survival data, decreased (fourteen stopped and four and the log rank test was used to compare decreased) their pain medications. the survival curves. The relationships between independent preoperative Three patients did not improve and still variables and treatment outcomes were complaining of pain as pre-procedure. analyzed with Wilcoxon singed ranks test. Repeated injection was done, two of them Other side effects were with Fisher exact had a good response but the third did not test. Chi2 was used for comparison. respond to block.

Table (1): Descriptive statistics for the studied patient's demography and neurolysis.

Count Parameters No. % Mean ± SD 45.8 ± 9.51 Age (years) Range 35 - 60 Females 12 57.1% Sex Males 9 42.9% No pain 0 0.0% Mild 0 0.0% Pain before Moderate 7 33.3% Severe 14 66.7% No pain 15 71.4% Mild 3 14.3% Pain after Moderate 2 9.5% Severe 1 4.8%

All of them underwent to block by absolute alcohol at the level of percutaneous CT guided mandibular nerve foramen ovale (Figure 1).

387 PRIMARY EXPERIENCE WITH CT GUIDED MANDIBULAR NERVE BLOCK...

Figure (1): CT guided percutaneous mandibular nerve injection at its exit from foramen ovale.

According to outcome results, many decrease in the level of pain after than patients had significant improvement. before injection (p value was 0.00001 - There was a highly statistically significant Table 2).

Table (2): Comparison between the level of pain before and after injection. Parameters P ain before Pain after Chi - square test

Pain level No. % No. % X2 P - value No pain 0 0.0% 15 71.4% Mild 0 0.0% 3 14.3% 32.04 0.00001 Moderate 7 33.3% 2 9.5% Severe 14 66.4% 1 4.8%

Regarding adverse effects, peripheral of trigeminal nerve. According to the nerve blocks were invariably associated ICHD-II criteria (international classifica- with swelling and discomfort lasting tion of headache disorders II), classic TN several days. Anesthesia dolorosa is the most common idiopathic disorder developed in one case after repeated characterized by brief electric shock like blocks. pain, abrupt in onset and termination, limited to distribution of one or more DISCUSSION division of trigeminal nerve (Bokhari, TN is a debilitating syndrome consist- 2012). Advances in imaging and improved ing mainly of unilateral short bursts of understanding of the physiology and lancinating pain in one or more branches anatomy of pain have led to significant

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development in neurosurgical manage- other previous studies showed that ment (Chenur and Colin, 2017). repeated TNB with alcohol did not lose Neuro-destructive procedures is effectiveness, even after 14 blocks had indicated with regards to medically been administered in one individual over refractory cases of trigeminal neuralgia many years. (Malgorzata et al., 2015). TNB with In this study, significant pain relief, alcohol is an accepted treatment for TN, occurred by decreased VAS (decreased but is not widely used as other severity of pain), and decreased BNI-ps percutaneous procedures or microvascular (decreased analgesic consumption) 2 decompression because it provides limited weeks after injection and continued pain relief and the repeated blocks have a throughout follow up period. lower success rate and higher morbidity Pain relieve after 1 and 2 years in including neuritis (Han and Kim, 2010). studied patients were 71.4% and 61.9% Therefore, we evaluated the efficacy of compared with the study of Han and Kim alcohol block on the mandibular division (2010) who stated that 70% and 62% of trigeminal nerve as a treatment of TN. occurred after the same durations Neurolytic agents like alcohol act respectively. immediately after coming into contact Few studies have been conducted on with the nerve fiber, and there is a rise in TNB with alcohol or its related the endoneural fluid pressure, secondary complications. Macleod and Patton to the mast cell degeneration and release (2007) reported that 4% of their patients of vasoactive substances. The elevated experienced local symptoms such as pain, pressure cause stretching of the perineu- burning, swelling, local infection, and rium and compression of perineural avascular necrosis of the skin. Kyung et vessels which lead to ischemia of nerve al. (2017) reported that 8.6% of their fiber and interruption of nerve impulses. It cases experienced complications. The also extracts cholesterol, phospholipids, most common complication was sensory and cerebrosides from the nervous tissue discomfort including itching, bothersome and causes perecipitation of lipoproteins dysesthesia, and deep hyposthesia in 5.7% and mucoprotiens (Dwarkadas et al., of patients. The majority resolved within 6 2016). months. The other complications were Han and Kim (2010) proved that pain also subsided or well tolerated by patients relief duration observed in their study of in several months. mandibular nerve block with alcohol in Generally, all neuro-ablative procedures comparable with that reported for for TN treatment involved trigeminal alternative techniques such as radio- nerve disturbances, both sensory and frequency, thermo-coagulation. The rates motor, and troublesome dysesthetic of complete pain relief after 1, 2 and 5 disturbances affect approximately 4 to years if procedures were 70%-90%, 62%- 10% of patients treated with any ablative 65% and 51%-56% respectively. technique for TN. Anesthesia dolorosa TNB with alcohol became less and corneal sensory disturbance can occur effective in terms of pain relief duration after denervation procedure for TN, and increased morbidity when treatment especially in patients that undergo RF in was repeated. Although Shah et al. (2011) whom it occurs at a rate of 0.3-22%. reported that pain free interval of repeated Percutaneous surgical techniques are less block was shorter than first block, the likely to be associated with mortality or

389 PRIMARY EXPERIENCE WITH CT GUIDED MANDIBULAR NERVE BLOCK... hearing loss, which is their greatest Ballontyne JC, Rathmell JP, editors. Bonica's th benefit as compared with MVD (Kyung management of pain, 4 ed, Pbl.: Lippincott, et al., 2017). pp: 1401-1423. 4. Dwarkadas KB, Sajay B, Sanjeeva G and Anesthesia dolorosa occurred in 4.8% Raghbir SP (2016): Pharmacotherapy of of patients compared with Han and Kim drugs used in interventional pain treatmen (2010) who stated that 11.3% of patients procedures, interventional pain management: a nd underwent alcoholic nerve block. They practical approach 2 ed. Pbl. Jaypee Brothers Publisheres Ltd, London, UK, chapter 5: 48- complained of parasthesia, dysesthesia, or 52. deep sensory loss, 4.3% of masseter muscle weakness, 1.8% of heavy 5. Greenberg MS (2016): Trigeminal neuralgia; Handbook of Neurosurgery, 8th ed, Pbl. salivation, 1.8% of tinnitus, and 0.6% Thieme Publishers New York, USA, 28: 480- hematoma in the upper cheek, although all 493. study patients had varying degrees of 6. Han KR and Kim CH (2010) : The long-term sensory deficit on the mandibular area. outcome of mandibular nerve block with However, all sensory discomforts alcohol for the treatment of trigeminal gradually decrease, patients adapted neuralgia, Anesthesia and Analgesia, 3 (2): without medication, and the majority of 550-553. complications resolved within 6 months. 7. John YK (2016): Measurement of trigeminal No significant difference in the incidence neuralgia pain – Penn facial pain scale, of complications was found between Neurosurg Clin N Am., 27: 327- 336. patients with and without previous alcohol 8. Koizuka S, Nikujina K and Mieda RI (2014): blocks. CT guided nerve block; a review of the features of CT fluoroscopic guidance for nerve CONCLUSION block. Anesthesia, 28: 94-101. Neurolytic mandibular nerve block 9. Kyung RH, Yun JC, Jung DL and Chan K (2017): Trigeminal nerve block with alcohol offered a simple office-based neuro- for medically intractable classic trigeminal surgical option for treating intractable and neuralgia: long-term clinical effectiveness on pharmacologically unresponsive TN. The pain. Int. J. Med Sci., 14(1):29-36. advantage of CT over plain X-ray 10. Malgorzata MM, Bartosz H, Dariusz K, fluoroscopy was the proper visualization Agnieszka S and Hanna K (2015): The of the foramen ovale facilitating the effectiveness of neurolytic block of injection of neurolytic substance properly, sphenopalatine ganglion using zygomatic reducing the incidence of side effects. approach for the management of trigeminal neuropathy. Neurologia I Neurochirurgia, REFERENCES Polska, 49: 389 – 394. 11. McLeod NM and Patton DW 1. Bokhari K (2012): Trigeminal neuralgia (2007): Peripheral alcohol injections in the involving all three branches of trigeminal management of trigeminal neuralgia. Oral nerve treated by peripheral , An Surg., Oral Med., Oral Pathol., Oral Radiol. interesting case report; The Internet Journal of and Endod., 104: 12-17. Dental Science, 10 (2): 1-5. 12. Shah SA, Khan MN, Shah SF, Ghafoor A 2. Chenur O and Colin SH (2017): Surgical management of chronic pain. Surgery, 35 (2): and Khattak A (2011): Is peripheral alcohol 110-112. injection of value in the treatment of trigeminal neuralgia? An analysis of 100 cases. Int. J. 3. Curatolo M and Bogduk N (2010): Diagnostic Oral Maxillofac. Surg., 40: 388-392. and therapeutic nerve block In: Fishman SM,

390 SAMY M ABDELRAOUF et al ﺧﺑرة أوﻟﯾﺔ ﻓﻲ اﻹﺳﺗدﻻل ﺑﺟﮭﺎز اﻷﺷﻌﺔ اﻟﻣﻘطﻌﯾﺔ ﻹﺣﺻﺎر اﻟﻌﺻب اﻟﻔﻛﻲ ﻓﻲ ﻣرﺿﻰ إﻋﺗﻼل اﻟﻌﺻب اﻟﻣﺧﻲ اﻟﺧﺎﻣس

ﺳﺎﻣﻲ ﻣﻮﺳﻰ ﻋﺒﺪاﻟﺮؤوف* - أﺷﺮف ﻣﺤﻤﺪ ﻋﻨﺎﯾﺖ - ﻋﻼ إﺳﻤﺎﻋﯿﻞ ﺻﺎﻟﺢ

ﻗﺴﻤﻲ ﺟﺮاﺣﺔ اﻟﻤﺦ واﻷﻋﺼﺎب*و اﻷﺷﻌﺔ اﻟﺘﺸﺨﯿﺼﯿﺔ - ﻛﻠﯿﺔ طﺐ اﻷزھﺮ (ﺑﻨﺎت)

ﺧﻠﻔﯿﺔ اﻟﺒﺤﺚ: إﻋﺘﻼل اﻟﻌﺼﺐ اﻟﺨﺎﻣﺲ ھﻮ ﻣﺘﻼزﻣﺔ اﻷﻟﻢ اﻟﻮﺟﮭﻲ اﻟﻤﻌﺮوﻓﺔ ﺟﯿﺪا واﻟﺘﻲ ﺗﺘﻤﯿﺰ ﺑﻨﻮﺑﺎت ﻣﻦ ﺻﺪﻣﺔ اﻷﻟﻢ اﻟﺸﺪﯾﺪ ﻓﻲ اﻟﻮﺟﮫ ﯾﺘﻮزع ﻋﻠﻰ ﻣﺴﺎر اﻟﻌﺼﺐ اﻟﺨﺎﻣﺲ أو أﺣﺪ ﻓﺮوﻋﮫ، وﯾﻌﺪ ﺗﺄﺛﺮ اﻟﻌﺼﺐ اﻟﻔﻜﻲ ﺷﺎﺋﻌﺎ ﻓﻲ ھﺬه اﻟﺤﺎﻻت.

اﻟﮭﺪف ﻣﻦ اﻟﺒﺤﺚ: دراﺳﺔ ﺗﺄﺛﯿﺮ ﺣﻘﻦ ﻣﻮاد ﻣﺨﺮﺑﺔ ﻟﻠﻌﺼﺐ ﺣﻮل اﻟﻌﺼﺐ اﻟﻔﻜﻲ ﻓﻲ ﺣﺎﻻت إﻋﺘﻼل اﻟﻌﺼﺐ اﻟﺨﺎﻣﺲ (اﻟﻔﺮع اﻟﻔﻜﻲ) ﻏﯿﺮ اﻟﻤﺴﺘﺠﯿﺒﺔ ﻟﻠﻌﻼج اﻟﺪواﺋﻲ.

اﻟﻤﺮﺿﻲ وطﺮق اﻟﺒﺤﺚ: ﺗﻀﻤﻨﺖ ھﺬه اﻟﺪراﺳﺔ واﺣﺪ وﻋﺸﺮﯾﻦ ﻣﺮﯾﻀﺎ ﻣﻦ اﻟﺬﯾﻦ ﯾﻌﺎﻧﻮن آﻻم اﻟﻌﺼﺐ اﻟﺨﺎﻣﺲ ﻋﻠﻰ ﻣﺴﺘﻮى اﻟﻔﺮع اﻟﻔﻜﻲ ، واﻧﻄﺒﻘﺖ ﻋﻠﯿﮭﻢ ﺷﺮوط اﻟﺪراﺳﺔ ﺑﺎﻹﺳﺘﺪﻻل ﺑﺠﮭﺎز اﻷﺷﻌﺔ اﻟﻤﻘﻄﻌﯿﺔ ﻟﺤﻘﻦ اﻟﻌﺼﺐ ﺑﺎﻟﻜﺤﻮل اﻟﻤﺮﻛﺰ ﻋﻨﺪ ﺧﺮوﺟﮫ ﻣﻦ ﻗﺎع اﻟﺠﻤﺠﻤﺔ، وﺗﺮاوﺣﺖ أﻋﻤﺎرھﻢ ﺑﯿﻦ ١٨ و٦٠ ﻋﺎﻣﺎ، وﻛﺎﻧﺖ ﻧﺴﺒﺔ اﻟﺬﻛﻮر إﻟﻰ اﻹﻧﺎث ٣:٤، وﺟﻤﯿﻌﮭﻢ ﻛﺎﻧﻮا ﯾﻌﺎﻧﻮن ﻣﺎ ﺑﯿﻦ إﻋﺘﻼل ﺷﺪﯾﺪ إﻟﻰ ﻣﺘﻮﺳﻂ وﻟﻢ ﯾﺴﺘﺠﯿﺒﻮا ﻟﻠﻌﻼج اﻟﺪواﺋﻲ، وﻗﺪ ﺗﻢ ﺗﺤﺪﯾﺪ ﻧﻘﻄﺔ دﺧﻮل اﻹﺑﺮة وإﺗﺠﺎھﮭﺎ ﺑﺎﻹﺳﺘﺪﻻل ﺑﺠﮭﺎز اﻷﺷﻌﺔ اﻟﻤﻘﻄﻌﯿﺔ ، وﺗﻢ ﺣﻘﻦ اﻟﻜﺤﻮل ﺣﻮل اﻟﻌﺼﺐ اﻟﻔﻜﻲ ﻋﻨﺪ ﺧﺮوﺟﮫ ﻣﻦ اﻟﺜﻘﺐ اﻟﺒﯿﻀﺎوي ﺑﻘﺎع اﻟﺠﻤﺠﻤﺔ.

اﻟﻨﺘﺎﺋﺞ: ﺗﺤﺴﻨﺖ اﻟﺤﺎﻻت ﺑﻨﺴﺒﺔ ٨٥٫٧٪، و اﺧﺘﻔﻰ اﻷﻟﻢ ﺗﻤﺎﻣﺎ ﻓﻲ ٧١٫٤ ٪، ﻣﻨﮭﻢ وﻗﻠﺖ ﺣﺪﺗﮫ ﻓﻲ ١٩٪، ﺑﯿﻨﻤﺎ ﻟﻢ ﯾﺘﺤﺴﻦ ٩٫٦ ٪ ﻣﻦ اﻟﻤﺮﺿﻰ وﻗﺪ ﺗﻢ ﻣﺘﺎﺑﻌﺔ اﻟﻤﺮﺿﻰ وإﻋﺎدة اﻟﺤﻘﻦ ﻟﻠﺤﺎﻻت اﻟﺘﻲ ﻗﻞ ﻓﯿﮭﺎ اﻷﻟﻢ واﻟﺤﺎﻻت اﻟﺘﻲ ﻟﻢ ﺗﺘﺤﺴﻦ. وﺑﻌﺪ ﻋﺎﻣﯿﻦ ﻣﻦ ﻣﺘﺎﺑﻌﺔ اﻟﻤﺮﺿﻰ، ﻛﺎﻧﺖ ﻧﺴﺒﺔ اﻟﻤﺮﺿﻰ اﻟﺬﯾﻦ ﻻ ﯾﻌﺎﻧﻮن ﻣﻦ اﻷﻟﻢ ھﻲ ٦١٫٩ ٪.

اﻹﺳﺘﻨﺘﺎج: ﯾﻌﺪ اﻹﺳﺘﺪﻻل ﺑﺎﻷﺷﻌﺔ اﻟﻤﻘﻄﻌﯿﺔ ﻹﺣﺼﺎر اﻟﻌﺼﺐ اﻟﻔﻜﻲ ﻋﻦ طﺮﯾﻖ ﺣﻘﻨﮫ ﺑﻌﻮاﻣﻞ ﻣﺨﺮﺑﺔ ﻟﻠﻌﺼﺐ ﻛﺎﻟﻜﺤﻮل اﻟﻤﺮﻛﺰ ﻣﻦ اﻟﺨﯿﺎرات اﻟﮭﺎﻣﺔ واﻟﻔﻌﺎﻟﺔ ﻛﺈﺣﺪى طﺮق اﻟﻌﻼج ذو اﻟﺘﺪﺧﻞ اﻟﻤﺤﺪود ﻓﻲ ﺣﺎﻻت إﻋﺘﻼل اﻟﻌﺼﺐ اﻟﺨﺎﻣﺲ اﻟﺘﻲ ﻟﻢ ﺗﺴﺘﺠﺐ ﻟﻠﻌﻼج اﻟﺪواﺋﻲ ﺣﯿﺚ أﻧﮫ ﯾﻌﻄﻰ ﻧﺘﺎﺋﺞ أﻛﺜﺮ دﻗﺔ وأﻣﺎﻧﺎ و ﺑﺄﻗﻞ ﻣﻀﺎﻋﻔﺎت ﻣﻤﻜﻨﺔ .