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Show Horner Syndrome Following a Selective Cervical Nerve Root Block Kevin Kaplowitz, MD, Andrew G. Lee, MD Abstract: A 31-year-old man with cervical degenerative disc disease was seen at an outside institution for a right selective nerve root block at C7. Following the procedure, he had right ptosis and miosis. Pharmacologic testing confirmed a right Horner syndrome. MRI and MRA showed no arterial dissection. This report documents the unusual occurrence of permanent Horner syndrome following a selective cervical nerve root block. Journal of Neuro-Ophthalmology 2011;31:54-55 doi: 10.1097/WNO.0b013e3181ea9cb1 2011 by North American Neuro-Ophthalmology Society A31-year-old man with a history of pain from cervical degenerative disc disease was seen at an outside in-stitution for a right selective cervical nerve root block at C7. He reported intermittent stabbing pain in the back and right side of his neck, and 4 years earlier he had undergone the same procedure without complication. During the current cervical procedure, he received a 6-mL injection consisting of 40 mg Kenalog in 0.25% Marcaine. On awakening from anesthesia his radicular pain had resolved, but he noted a droopy right upper eyelid. Two months later, he was seen in The Methodist Hospital neuro-ophthalmology clinic. Vision was 20/20 in each eye, and the remainder of the examination was normal except for pupil size and eyelid position. In darkness, pupils measured 3 mm on the right eye and 4 mm on the left eye (Fig. 1), and the right pupil showed dilation lag. There was 1 mm of right ptosis. Topical apraclonidine drops confirmed the diagnosis of a right Horner syndrome (Fig. 2). Contrast-enhanced MRI of the head and neck was normal, andMRA of the neck showed no evidence of carotid or vertebral dissection. Selective nerve root block (SNRB) is an increasingly utilized procedure for both confirmation of diagnosis and treatment of radicular pain (1). It is being used to empir-ically help define the etiology of pain in patients and to deliver local therapeutics. The procedure typically involves injecting 1-2 mL of a combination of a local anesthetic and steroid. Fluoroscopic guidance is used first to achieve ap-propriate positioning, and then contrast is injected to an-ticipate where the medication will be delivered. In a review of 4,612 patients undergoing a cervical SNRB, the only neurological complication involved one patient who had a seizure (2). In a prospective review of 799 SNRBs, 5 patients had transient sympathetic blockade leading to ptosis and miosis, but these all resolved (3). There are 3 reported cases of vertebral artery dissection following fluoroscopically guided cervical SNRB, but Horner syn-drome was not noted in any of these cases (4,5). Other reported complications of SNRB include direct damage to the nerve or the nearby radicular artery; transient extremity paresis; cerebral, cerebellar, or spinal cord in-farction; cardiac arrhythmia; meningitis; syncope; dural puncture; and death (4). Some may be due to the physical trauma of the injection, others from particulate emboli of the injected steroid preparation, and yet others from the inadvertent injection of the anesthetic agent into the ra-dicular artery, which usually results in motor weakness (6). In our patient, the cause of Horner syndrome was most likely damage to the second-order neuron of the oculo-sympathetic pathway. The operative record noted that a 22-gauge needle was inserted near the right seventh cervical nerve root under fluoroscopic guidance. While transient sympathetic blockade is possible from local absorption of FIG. 1. Patient examination reveals right ptosis and miosis, 2 months after a selective cervical nerve root block. Department of Ophthalmology, The Methodist Hospital, Houston, Texas. The authors report conflicts of interest. Address correspondence to Kevin Kaplowitz, MD, 700 University Boulevard, Galveston, TX 77555; E-mail: kbkaplow@utmb.edu 54 Kaplowitz and Lee: J Neuro-Ophthalmol 2011; 31: 54-55 Clinical Observation Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. the injected anesthetic, our patient's symptoms were present 2 months following SNRB, arguing against a medication-related neuropathy. The needle could have perforated the vertebral artery. The MRI and MRA revealed no such pathology; however, a dissection could potentially have already healed. The most likely possibility is direct damage from the needle to the second-order sympathetic neurons as they ascend to the superior cervical ganglion. Although Horner syndrome is well recognized following stellate ganglion block, we found no other reports of a permanent Horner syndrome following a selective cervical nerve root block. Physicians involved with selective nerve blocks should be aware of this potential complication and consider including this during discussion of informed consent with the patient. REFERENCES 1. Gajraj NM. Selective nerve root blocks for low back pain and radiculopathy. Reg Anesth Pain Med. 2004;29:616-617. 2. Schellhas KP, Pollei SR, Johnson BA, Golden MJ, Eklund JA, Pobiel RS. Selective cervical nerve root blockade: experience with a safe and reliable technique using an anterolateral approach for needle placement. Am J Neuroradiol. 2007;28:1909- 1911. 3. Pobiel RS, Schellhas KP, Eklund JA, Golden MJ, Johnson BA, Chopra S, Broadbent P, Myers ME, Shrack K. Selective cervical nerve root blockade: prospective study of immediate and longer term complications. AJNR Am J Neuroradiol. 2009;30:507-511. 4. Wallace MA, Fukui MB, Williams RL, Ku A, Baghai P. Complications of cervical selective nerve root blocks performed with fluoroscopic guidance. AJR Am J Roentgenol. 2007;188:1218-1221. 5. Rozin L, Rozin R, Koehler SA, Shakir A, Ladham S, Barmada M, Dominick J, Wecht CH. Death during transforaminal epidural steroid nerve root block (C7) due to perforation of the left vertebral artery. Am J Forensic Med Pathol. 2003;24:351-355. 6. Karasek M, Bogduk N. Temporary neurologic deficit after cervical transforaminal injection of local anesthetic. Pain Med. 2004;5:202-205. FIG. 2. One hour following administration of apraclonidine drops to both eyes, anisocoria has reversed and the right-sided ptosis is slightly improved confirming right Horner syndrome. Clinical Observation Kaplowitz and Lee: J Neuro-Ophthalmol 2011; 31: 54-55 55 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
