[ resident s case problem ]

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1 David G. Greathouse, PT, PhD, ECS, FAPTA1 Anand Joshi, MD2 Radiculopathy of the Eighth Cervical Nerve Radiculopathy involving the cervical nerve roots may be caused by spondylosis (degenerative joint disease or degenerative disc disease), with or without osteophytes, herniated nucleus pulposis, a space occupying lesion (tumor or infection), or traumatic avulsion (Erb-Duchenne C5-C6 or Klumpke palsy C8-T1). 4,6 The most frequently involved cervical nerve root is C7 (31%-81%), followed by C6 (19%-25%), C5 (2%-14%), and C8 (4%-12%). 4,6-7 Usually the site of the lesion is proximal to the posterior root ganglion, formerly named dorsal root ganglion, and, thus, sensory nerve conduction studies (NCSs) will be normal. 4,6 A postganglionic lesion of the nerve root may produce abnormalities in the sensory NCSs. 4,6 t STUDY DESIGN: Resident s case problem. t BACKGROUND: The C8 nerve root is the least commonly encountered of cervical radiculopathies. The purpose of this resident s case problem is to provide an unusual presentation of a C8 radiculopathy, without cervical or proximal upper quarter symptoms, diagnosed by a combination of physical examination, electromyography (EMG) and nerve conduction studies (NCSs), and imaging. t DIAGNOSIS: A 49-year-old, right-hand dominant male was referred to the EMG/NCS laboratory for a suspected left ulnar neuropathy at the elbow. A physical examination, NCS, and EMG were performed, and a C8 radiculopathy involving both the anterior and posterior primary rami was identified. Following the EMG and NCS evaluation, the patient had enhanced magnetic resonance imaging studies that confirmed a foraminal C7-T1 herniation and associated small central disc protrusion. The patient was then referred to neurosurgery for further consultation and subsequent surgical intervention. The patient underwent a Following the formation of the spinal nerve containing both motor and sensory components, the spinal nerve immediately branches into the posterior (dorsal) and anterior (ventral) primary C7-T1 laminectomy, mesial facetectomy, and foraminotomy, and excision of a herniated disk using an operating microscope. The neurosurgeon noted that there was a large disk herniation containing some disk material immediately anterior to the C8 motor root, that impinged directly on the motor root. One month postoperatively, the patient had decreased pain and numbness and tingling in his arm and his hand weakness had improved. t DISCUSSION: The report illustrates the utility of a combination of physical examination, EMG and NCSs, and imaging in the diagnosis of a C8 radiculopathy in a patient presenting with forearm and hand symptoms but without cervical or upper quarter symptoms. t LEVEL OF EVIDENCE: Diagnosis, level 4. J Orthop Sports Phys Ther 2010;40(12): doi: /jospt t KEY WORDS: electromyography, magnetic resonance imaging, neck nerve conduction studies, ulnar nerve rami. 8,9 Just prior to reaching the transverse process, the C8 posterior primary rami divides into 2 terminal branches (medial and lateral) and innervates the erector spinae and transversospinalis paravertebral muscles, provides cutaneous innervation of the skin over and lateral to the vertebra, and innervates the zygoapophyseal (facet) joint. 8,9 The anterior primary rami of the C8 nerve root joins with the anterior primary rami of T1 to form the inferior (lower) trunk of the brachial plexus. The lower trunk then bifurcates to contribute to the anterior and posterior divisions of the brachial plexus. The posterior division contributes to the posterior cord of the brachial plexus. The anterior division continues as the medial cord of the brachial plexus. 8,9 The medial cord of the brachial plexus terminates in the ulnar nerve, and nerve branches of the medial cord include the medial pectoral nerve, medial cutaneous nerve of the arm, medial cutaneous nerve of the forearm, and the medial root contribution to the median nerve. 8,9 Patients with a C8 radiculopathy typically present with pain radiating into digits 4 and 5, with paresthesia (numbness/ tingling) in the palmar and dorsal surface of both digits, and may present with lower cervical pain that may radiate into the medial arm and forearm. 4,6 Patients with a suspected C8 radiculopathy may have weakness involving the long finger extensors and flexors, including the flexor 1 Director, Clinical Electrophysiology Services, Texas Physical Therapy Specialists, New Braunfels, TX; Adjunct Professor, US Army-Baylor University Doctoral Program in Physical Therapy, Fort Sam Houston, TX. 2 Spine Specialist, Spine Diagnostic and Treatment Center, Austin, TX. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of the Army or the Department of Defense. The authors have no financial affiliation (including research funding) or involvement with any commercial organization that has a direct financial interest in any matter included in this manuscript. Address correspondence to Dr David G. Greathouse, 3211 Crystal Path, San Antonio, TX, greathoused1@yahoo.com journal of orthopaedic & sports physical therapy volume 40 number 12 december

2 pollicis longus, flexor digitorum profundus, and extensor pollicis longus, thenar/ hypothenar muscles, and, to a lesser extent, the intrinsic hand muscles. 4,6,8 In patients with suspected C8 radiculopathy, NCSs and electromyography (EMG) should be performed to confirm or exclude the diagnosis, as well as other cervical radiculopathies, ulnar nerve TABLE 1 Electromyography and Nerve Conduction Studies Findings for Ulnar Neuropathy at the Wrist or Elbow, Medial Cord Plexopathy, Inferior Trunk Plexopathy, or C8 Radiculopathy Ulnar nerve, wrist (Guyon s canal) Ulnar nerve, elbow (cubital tunnel) Medial cord, brachial plexus Inferior (lower) trunk, brachial plexus C8 radiculopathy (preganglionic) Abnormal Findings Prolonged ulnar nerve digit 5 and palmar distal sensory latencies Prolonged ulnar nerve distal motor latency Decreased amplitude digit 5 and palmar sensory nerve action potentials and distal motor latency compound motor action potential EMG findings: abnormal spontaneous electrical activity and denervation, first dorsal interosseous, abductor digiti minimi Prolonged ulnar nerve motor nerve conduction velocity of above elbow to below elbow Prolonged ulnar nerve sensory nerve conduction velocity above elbow to below elbow EMG findings: as for ulnar neuropathy at the wrist, plus flexor carpi ulnaris and flexor digitorum profundus of digits 4 and 5 EMG findings: as for ulnar neuropathy at the elbow plus abductor pollicis brevis, flexor pollicis longus, flexor digitorum profundus of digits 2 and 3, pectoralis major (sternocostal fibers) Decreased sensory nerve action potential amplitude and/or prolonged latency ulnar nerve distal sensory latencies and distal motor latency, dorsal ulnar cutaneous nerve distal sensory latency, medial cutaneous nerve of the forearm distal sensory latency Slowed ulnar nerve motor nerve conduction velocity supraclavicular to axilla EMG findings: as for medial cord plexopathy plus extensor pollicis longus and extensor indicis Decreased sensory nerve action potential amplitude and/or prolonged latency ulnar nerve distal sensory latencies and distal motor latency, dorsal ulnar cutaneous nerve distal sensory latency, medial cutaneous nerve of the forearm distal sensory latency EMG findings: as for inferior trunk plexopathy plus low cervical (spinal level C6-C7-T1) paravertebral muscles Normal Findings* Normal ulnar nerve motor nerve conduction velocities below elbow to wrist, and above elbow to below elbow Normal dorsal ulnar cutaneous nerve distal sensory latency EMG findings: normal abductor pollicis brevis, flexor pollicis longus, extensor pollicis longus, flexor carpi ulnaris, flexor digitorum profundus of digits 4 and 5 Normal ulnar nerve distal sensory latency and distal motor latency Normal ulnar nerve motor nerve conduction velocities of below elbow to wrist and axilla to above elbow Normal medial cutaneous nerve of the forearm distal sensory latency EMG findings: normal abductor pollicis brevis, flexor pollicis longus, extensor pollicis longus EMG findings: normal extensor pollicis longus, extensor indicis, extensor digitorum, extensor carpi radialis, flexor carpi radialis, biceps brachii, triceps brachii, deltoid, cervical paravertebral muscles Normal ulnar nerve distal motor latency and motor nerve conduction velocities of below elbow to wrist and above elbow to below elbow Normal lateral cutaneous nerve of the forearm distal sensory latency EMG findings: normal extensor digitorum, extensor carpi radialis, flexor carpi radialis, biceps brachii, triceps brachii, deltoid, cervical paravertebral muscles Normal ulnar nerve distal motor latency and motor nerve conduction velocities of below elbow to wrist and above elbow to below elbow Normal lateral cutaneous nerve of the forearm distal sensory latency Normal ulnar nerve distal sensory latency, distal motor latency, and motor nerve conduction velocity of below elbow to wrist and above elbow to below elbow Normal medial cutaneous nerve of the forearm, lateral cutaneous nerve of the forearm, and dorsal ulnar cutaneous nerve distal sensory latencies and sensory nerve action potential amplitudes EMG findings: normal screen for C5-C7 upper extremity musculature Abbreviation: EMG, electromyography (needle). * Including normal sensory and motor nerve conduction and electromyography studies of the median and radial nerves, and electromyography screen of C5-C7 musculature in the upper extremity. Demyelinating (myelinopathy) neuropathic process. Axon loss (axonopathy) neuropathic process. An ulnar nerve axonopathy at the elbow (cubital tunnel) may occur proximal to the innervation of the flexor carpi ulnaris, thus the flexor carpi ulnaris would be normal on EMG. Ulnar nerve lesions proximal to the innervation of the flexor carpi ulnaris may demonstrate abnormal spontaneous electrical activity and denervation in the flexor carpi ulnaris. 4,6 A myelinopathy of the ulnar nerve at the elbow would have normal motor and sensory conduction of the below elbow to wrist forearm segment of the ulnar nerve, as well as normal ulnar nerve distal motor and sensory latencies, sensory nerve action potentials, and compound motor action potentials. However, an axonopathy of the ulnar nerve at the elbow may cause a slowed motor nerve conduction velocity and sensory nerve conduction velocity of the below elbow to wrist forearm segment of the ulnar nerve and prolonged distal motor and sensory latencies of the ulnar nerve at the wrist. These changes distal to the lesion of the ulnar nerve at the elbow may be due to the loss of large-diameter motor and sensory fibers. An axonopathy of the ulnar nerve at the elbow may also cause decreased or absent sensory nerve action potential and compound motor action potential amplitudes of the ulnar nerve at the wrists. 4,6 A myelinopathy of the medial cord or inferior trunk would have normal motor and sensory conduction of the below elbow to wrist forearm segment and the above elbow to below elbow segment of the ulnar nerve, as well as normal ulnar nerve distal motor and sensory latencies, sensory nerve action potentials, and compound motor action potentials. However, an axonopathy of the medial cord or inferior trunk may cause a slowed motor nerve conduction velocity and sensory nerve conduction velocity of the below elbow to wrist forearm and the above elbow to below elbow segments of the ulnar nerve, and prolonged distal motor and sensory latencies of the ulnar nerve at the wrist. These changes distal to the lesion of the medial cord or inferior trunk may be due to the loss of largediameter motor and sensory fibers. An axonopathy of the medial cord or inferior trunk may also cause decreased or absent sensory nerve action potential and compound motor action potential amplitudes of the ulnar nerve at the wrists and elbow, as well as the dorsal ulnar cutaneous nerve and medial cutaneous nerve of the forearm. 4,6 812 december 2010 volume 40 number 12 journal of orthopaedic & sports physical therapy

3 mononeuropathies (wrist or cubital tunnel), medial cord plexopathy, or inferior trunk plexopathy. 4,6 An optimal EMG scan for cervical radiculopathy must include needle examination of the cervical paravertebral muscles. 2-4,6 For identifying cervical radiculopathy, an optimal (96%- to 100%-identified radiculopathy) EMG scan should include 7 muscles sampled (6 upper extremity and paravertebral muscles). 3 Imaging studies, including magnetic resonance imaging (MRI) of the cervical spine and brachial plexus, radiographs, computer tomography (CT) scans, and myelograms, may also be useful to confirm the findings of a physical examination and NCS and EMG testing. 4,6,10 Numbness and tingling of digits 4 and 5 and weakness of the hand may also be seen in other neuropathic conditions. In addition to a physical examination, NCSs and EMG may assist in determining the cause of the patient s hand paresthesia and weakness. The ulnar nerve may be compromised at the wrist (Guyon s canal) or at the elbow (cubital tunnel). 4,6,8 For identifying an ulnar mononeuropathy at the wrist, NCS testing of the palmar and digit 5 distal sensory latencies of the ulnar nerve, distal sensory latency of the dorsal ulnar cutaneous nerve, and EMG testing of the first dorsal interosseous and abductor digiti minimi, as well as other C8-T1 innervated muscles, is performed. 4,6 Ulnar mononeuropathy at the elbow (cubital tunnel) may be localized by motor and sensory NCS testing of the ulnar nerve as it passes through the cubital tunnel. In addition to performing the NCS and EMG testing for a suspected ulnar mononeuropathy at the wrist, additional EMG testing to confirm an ulnar nerve mononeuropathy at the elbow includes examination of the flexor carpi ulnaris and flexor digitorum profundus of digits 4 and 5. 4,6 A medial cord brachial plexopathy expands the clinical presentation and may include possible involvement of muscles innervated other than by the ulnar nerve (eg, abductor pollicis brevis, flexor pollicis longus, flexor digitorum profundus of digits 2 and 3, and pectoralis major [sternocostal fibers]). NCS testing for brachial plexopathies includes examination of the medial cutaneous nerve of the forearm, lateral cutaneous nerve of the forearm, median and ulnar F waves, and motor nerve conduction velocity of the ulnar nerve from the Erb s point (supraclavicular) to the axilla. An inferior trunk (lower trunk) brachial plexopathy also includes examination of other C8 muscles innervated proximal to the medial cord (ie, extensor pollicis longus and extensor indicis). Further EMG testing of the cervical paravertebral muscles is necessary to confirm the presence of denervation in the posterior primary rami innervated muscles and thus place the lesion proximal to the inferior (lower) trunk. 4,6 TABLE 1 presents the normal and abnormal electrodiagnostic findings for ulnar neuropathy at the wrist and elbow, medial cord plexopathy, inferior trunk plexopathy, and C8 radiculopathy. For the C8 radiculopathy, Levin et al 7 identified the first dorsal interosseous, abductor digiti minimi, abductor pollicis brevis, flexor pollicis longus, and extensor indicis as the muscles involved with this level of nerve root compromise. This resident s case problem will include findings of an unusual presentation of a C8 radiculopathy, without cervical or upper quarter pain, that was eventually diagnosed by a combination of physical examination, EMG and NCSs, and imaging. DIAGNOSIS History The patient was a 49-year-old male, who was right hand dominant and a self-employed contractor. The patient was referred by his primary care physician to the EMG/NCS laboratory for a suspected left ulnar neuropathy at the elbow. The information provided by the patient included pain, numbness and tingling in the left medial forearm and left digits 4 and 5, left hand grip weakness, and no neck or upper quarter pain. In addition, MRI performed approximately 5 weeks prior to the EMG and NCS testing was read by a radiologist as mild and moderate cervical spondylosis including focal moderate degenerative changes at C5-C6 and C6-C7, but without confirmation of a foraminal mass at the C7-T1 level. At the time of the EMG and NCS examination, the patient reported a 3-month history of left upper extremity pain and numbness/tingling in the left medial forearm and left digits 4 and 5, including both the dorsal and palmar surfaces of the digits. The patient stated that he experienced weakness with gripping objects with his left hand. He reported no history of injury or trauma to either upper extremity or the neck. Other than the symptoms described above, the patient reported no other pain, numbness and tingling, or weakness in the left upper extremity, right upper extremity, or either lower extremity. He also reported no complaints of headache, visual problems, or difficulty with chewing or swallowing his food, and normal bowel and bladder function. The patient had a surgical resection of the cervical ribs, bilaterally, 10 years prior, secondary to bilateral shoulder pain related to thoracic outlet syndrome. The patient stated that his general medical health was good and that he was not being treated for any other health conditions. He had no history of diabetes, heavy metal exposure, thyroid disease, renal disease, or alcoholism. A review of systems was noncontributory for cardiovascular, pulmonary, gastrointestinal, genitourinary, or endocrine problems. There was no family history of neuromuscular disease. After completion of the patient s history and considering his current symptoms, the physical examination was directed toward performing a differential diagnosis, including left ulnar mononeuropathy at the elbow, medial cord plexopathy, infe- journal of orthopaedic & sports physical therapy volume 40 number 12 december

4 rior (lower) trunk plexopathy, or C8 radiculopathy as possibilities. Physical Examination The patient had normal and pain-free cervical active range of motion in all planes. The Spurling test was negative for neck or radicular symptoms in both upper extremities. A cranial nerve screen was performed, and normal function was determined for cranial nerves III/IV/VI, V, VII, IX/X, XI, and XII. Active mobility of both shoulders, elbows, forearms, wrists and fingers in all planes of motion was found to be normal. Decreased strength (3+/5) was noted for the left abductor pollicis brevis, opponens pollicis, dorsal interossei 1 to 4, palmar interossei 1 to 3, adductor pollicis, and abductor digiti minimi. There was 4/5 strength in the left extensor pollicis longus, extensor indicis, flexor pollicis longus, flexor carpi ulnaris, and flexor digitorum profundus of digits 4 and 5. The remaining musculature for the left upper extremity was considered normal (5/5). This included testing for the shoulder (flexion/extension, abduction/adduction, and internal/external rotation), elbow (flexion/extension), forearm (pronation/supination), wrist (flexion and extension), flexor digitorum superficialis, and extensor digitorum. In comparison, a similar comprehensive assessment for the right upper extremity indicated normal (5/5) strength for all muscle groups and individual muscles tested. No atrophy or clonus was present in either upper extremity. Muscle stretch reflexes were present and equal for the biceps, triceps, and brachioradialis bilaterally. The Hoffman reflex was absent bilaterally. There was decreased sensation of light touch and pain (pinprick) for the palmar and dorsal aspects of the left digits 4 and 5. Otherwise, there was normal light touch and pinprick sensation for all dermatomes (C4-T1) and peripheral nerves bilaterally. The Tinel sign was absent for the median nerve (wrists) and the ulnar nerve (wrists and elbows). The Phalen test was negative for the median nerve bilaterally. No changes in the radial pulse were noted during the scalene, costoclavicular, and TABLE 2 pectoralis minor/clavipectoral fascia maneuvers for thoracic outlet syndrome for either upper extremity. Nerve Conduction Study Measurements Nerve Left Right normal Median Palmar distal sensory latency (ms) Palmar amplitude sensory nerve action potential (µv) digit distal sensory latency (ms) digit amplitude sensory nerve action potential (µv) Motor Distal motor latency (ms) Amplitude compound motor action potential (mv) Motor nerve conduction velocity elbow to wrist (m/s) F wave Latency (ms) Ulnar Palmar distal sensory latency (ms) Palmar amplitude sensory nerve action potential (µv) digit distal sensory latency (ms) digit amplitude sensory nerve action potential (µv) nerve conduction velocity below elbow to wrist (m/s) 71 Not tested 50 nerve conduction velocity above elbow to below elbow (m/s) 76 Not tested 50 Motor Distal motor latency (ms) Amplitude compound motor action potential (mv) Motor nerve conduction velocity below elbow to wrist (m/s) Motor nerve conduction velocity above elbow to below elbow (m/s) F wave Latency (ms) Radial Distal sensory latency (ms) Amplitude sensory nerve action potential (µv) Lateral cutaneous nerve of the forearm Distal sensory latency (ms) 2.4 Not tested 3.2 Amplitude sensory nerve action potential (µv) 8 8 Medial cutaneous nerve of the forearm Distal sensory latency (ms) 2.4 Not tested 3.2 Amplitude sensory nerve action potential (µv) 9 8 Dorsal ulnar cutaneous nerve Distal sensory latency 1.6 Not tested 2.2 Amplitude sensory nerve action potential (µv) december 2010 volume 40 number 12 journal of orthopaedic & sports physical therapy

5 TABLE 3 Electromyography Measurements Motor Unit Potentials (Shape, Fibrillation Positive Amplitude, and interference Muscle (Left Upper Extremity) nerve Root insert Potentials Waves duration) Pattern First dorsal interosseous Ulnar C8-T1 Increased Normal 75% Abductor digiti minimi Ulnar C8-T1 Increased Normal 50% Abductor pollicis brevis Median C8-T1 Increased Polyphasic 50% Pronator teres Median C6-C7 Normal 0 0 Normal 100% Extensor carpi radialis longus Radial C6-C7 Normal 0 0 Normal 100% Flexor carpi ulnaris Ulnar C8-T1 Increased Normal 75% Flexor digitorum profundus of digits 4 and 5 Ulnar C8-T1 Increased Normal 75% Extensor pollicis longus Radial C7-C8 Increased Normal 75% Biceps brachii Musculocutaneous C5-C6 Normal 0 0 Normal 100% Triceps brachii Radial C6-C7-C8 Normal 0 0 Normal 100% Deltoid Axillary C5-C6 Normal 0 0 Normal 100% Supraspinatus Suprascapular C5-C6 Normal 0 0 Normal 100% Pectoralis major clavicular Lateral pectoral nerve C5-C6-C7 Normal 0 0 Normal 100% Pectoralis major sternocostal Medial pectoral nerve C8-T1 Increased Normal 100% Trapezius Cranial nerve XI C1-C2-C3-C4-C5 Normal 0 0 Normal 100% Midcervical paravertebral muscles Posterior primary rami C4-C5 Normal 0 0 Normal Low cervical paravertebral muscles Posterior primary rami C6-C7-C8 Increased Normal At the conclusion of the physical examination, the findings appear to place the site of the lesion at the left C8 nerve root and proximal to the left ulnar nerve, medial cord, and inferior trunk Nerve Conduction Studies NCSs and EMG were performed to further assist in confirming the diagnosis of a left C8 radiculopathy, while also determining the electrophysiologic status of the left ulnar nerve, medial cord, and inferior trunk. The Cadwell Sierra LT electromyograph and stimulator (Cadwell Laboratories, Inc, Kennewick, WA) were used to perform the NCS and EMG examinations. Specific details for performing the NCS and EMG examinations have been presented. 4-6 Nerve conduction data were collected with the skin temperature at the wrist maintained between 32 C to 33 C in both upper extremities. The NCS and EMG examinations performed on this patient followed a protocol established in this laboratory for the evaluation of a patient with a suspected upper extremity mononeuropathy, brachial plexopathy, or cervical radiculopathy. This protocol included performance of NCSs of both upper extremities for comparing NCS values between the symptomatic and nonsymptomatic extremities, as well as comparing the NCS values to a chart of normal values. The nerve conduction studies were normal for the bilateral ulnar nerves, bilateral superficial radial nerves, and left median, medial cutaneous nerve of the forearm, lateral cutaneous nerve of the forearm, and dorsal ulnar cutaneous nerves (TABLE 2). This included normal motor and sensory nerve conduction studies of the left ulnar nerve at the wrist, in the forearm, and across the elbow. However, the palmar distal sensory latency and distal motor latency of the right median nerve were prolonged (TABLE 2). These electrophysiologic findings were suggestive of a right median mononeuropathy at, or distal to, the wrist, which is an early demyelinating neuropathic process involving both the motor and sensory fibers. The patient was asymptomatic for pain, numbness, tingling, or weakness in the right median nerve distribution. Electromyography The results of the needle EMG examination are provided in TABLE 3. There was abnormal spontaneous electrical activity and denervation noted in the left first dorsal interosseous (ulnar C8-T1), abductor digiti minimi (ulnar C8-T1), abductor pollicis brevis (median C8-T1), extensor pollicis longus (posterior interosseous C7-C8), flexor carpi ulnaris (ulnar C8- T1), flexor digitorum profundus of digits 4 and 5 (ulnar C8-T1), pectoralis major sternocostal fibers (medial pectoral nerve C8-T1), and low cervical (C6-C7-T1 spinal level) paravertebral muscles. Otherwise, EMG testing of the other muscles in the left upper extremity was normal (TABLE 3). NCS and EMG Evaluation There is electrophysiologic evidence on this exam of a left C8 radiculopathy in the left upper extremity and left low cervical paravertebral muscles and a mild right median mononeuropathy at journal of orthopaedic & sports physical therapy volume 40 number 12 december

6 or distal to the wrist. There was no electrophysiologic evidence on this exam of a left C5-C7 radiculopathy, a left brachial plexopathy including the medial cord or inferior trunk, or a left ulnar nerve mononeuropathy. Imaging and Radiographic Studies Following the EMG and NCS examination, and after consultation with the patient s primary care provider and a consulting neurosurgeon, the patient was referred for computerized tomography (CT) of the cervical spine with myelogram, radiographs of the cervical spine, and chest radiograph. These studies were performed 2 weeks later and reviewed by a radiologist. The radiologist s report of the cervical spine radiographs indicated that there was mild and moderate cervical spondylosis, including focal moderate degenerative changes at C5-C6 and C6-C7 and perhaps minimal 2-mm anterolisthesis at C7-T1, with minimal retrolisthesis at C6- C7. There was no evidence of instability at C7-T1, based on radiographs taken at end range cervical flexion or extension. Oblique view radiographs showed a mild neural foraminal narrowing at C5-C6 bilaterally, as well as C6-C7 on the left. Chest radiographs were ordered, to rule out any lung pathology, including a Pancoast lesion. 10 The radiologist reported no evidence of acute abnormality, but there was evidence of postoperative changes noted in the shoulder region on the right and a mild elevation of the right hemidiaphragm. The CT with myelogram, without and with contrast of the cervical spine, showed a left foraminal soft tissue mass consistent with a schwannoma, although a foraminal herniation (disc or other soft tissue in the neural foramina) was not excluded. There was also evidence of a small central disc protrusion at C7-T1, a small left foraminal herniation and stenosis at C4-C5, and moderate bilateral foraminal narrowing at C5-C6. The radiologist stated that, after comparing the CT cervical spine with myelogram from a previous MRI study that was performed 2 months earlier, there was no confirmation of a foraminal mass at the left C7-T1 level. The radiologist was confident that the abnormality seen on the CT myelogram was not diagnostic and recommended a follow-up high-resolution contrast MRI. An MRI of the cervical spine, without and with contrast, was then performed a week later and compared with the CT myelogram. The radiologist s impression of the cervical spine MRI included left C7-T1 disc herniation into the left neural foramina and associated small central disc protrusion, but was negative for left C7-T1 foraminal schwannoma. There was also evidence of a small left disc herniation into the left neural foramina at C4-C5, stenosis at C4-C5, and a bilateral foraminal stenosis at C5-C6. Referral to Neurosurgery and Surgical Intervention Following the imaging and radiographic studies, and considering the findings of the physical examination and EMG and NCSs, the patient was referred to neurosurgery for consultation for a left C8 radiculopathy. The patient was evaluated by the neurosurgeon, who agreed with this diagnosis. The neurosurgeon suggested a surgical intervention for the left C8 radiculopathy, but the patient decided not to have surgery at that time and to continue to monitor the weakness in his left hand. No other interventions for this problem, including physical therapy, were provided. Approximately 1 year after the EMG and NCS testing and imaging studies, the patient had increased weakness in the left hand and, after consulting with his neurosurgeon, was scheduled for surgery. The preoperative diagnosis was a left C7-T1 herniated disk with left C8 radiculopathy. The operative diagnosis confirmed the left C7-T1 herniated disk with left C8 radiculopathy. The patient had a C7-T1 laminectomy, mesial facetectomy, and foraminotomy and excision of a herniated disk using an operating microscope. The posterior surgical approach was used with a linear incision made just off the midline of C7-T1. The neurosurgeon noted that there was a large disk herniation containing some disk material immediately anterior to the left C8 motor root that impinged directly on the motor root. After the overlying annulus was opened and the disk fragment removed, the left C8 motor nerve root was noted to be adequately decompressed. The surgical report did not indicate impingement of the left C8 sensory root. Postneurosurgical Intervention Evaluation The patient was evaluated by the neurosurgeon 1 month postoperatively. The patient reported some minimal soreness and tightness in his neck, but that his left arm pain was gone. The patient also stated that the numbness in the left hand and forearm was gradually resolving and that he continued with some weakness in the left hand. On physical examination, the patient was noted to have some decreased sensation in the left digit 5 to light touch, but this was improved from his preoperative status, and the motor strength in his left hand intrinsics had improved to 4/5. DISCUSSION The patient in this case had paresthesia and decreased sensation in the palmar and dorsal aspects of left digits 4 and 5 and the left medial forearm. In addition, the patient had weakness on manual muscle testing of the left dorsal and palmar interossei, abductor pollicis brevis, abductor digiti minimi, extensor pollicis longus, flexor carpi ulnaris, and flexor digitorum profundus of digits 4 and 5. However, the patient denied neck and upper quarter pain, and assessment of his cervical spine was normal. Following the physical examination of this patient, the findings of the examination placed the lesion proximal to the ulnar nerve at the elbow and most likely proximal to the brachial plexus. NCSs and EMG in this patient with a suspected left C8 radiculopathy provided electrophysiologic evidence that the abnormality was in fact at the eighth cer- 816 december 2010 volume 40 number 12 journal of orthopaedic & sports physical therapy

7 vical nerve root and not an ulnar nerve mononeuropathy at the wrist or elbow, medial cord brachial plexopathy, or inferior trunk brachial plexopathy. Imaging studies later confirmed the involvement of the left C8 nerve root. The normal NCS of the left upper extremity and the EMG examination of low cervical (C6-C7 spinal level) paravertebral muscles were key diagnostic findings in localizing the left C8 radiculopathy from the medial cord and inferior trunk brachial plexopathies. 4,6 Vargo and Flood 10 state that the possibility of a Pancoast lesion should be considered not only in the presence of brachial plexopathy, but also when C8 or T1 radiculopathy is found. In a case study report of a 64-year-old male with a 2-month history of left shoulder pain and left arm numbness at the medial aspect of the hand and forearm, the authors determined a severe left C8 radiculopathy as documented by EMG testing. 10 Motor and sensory NCS testing was normal in that patient. Subsequent radiographic evaluation, including cervical myelogram and chest radiographs, demonstrated a left apical lung tumor (Pancoast tumor) eroding through the C7 and T1 pedicles and T1 vertebral body, with cut-off of the left C8 nerve root. A Pancoast tumor has a known tendency to locally invade the nerve roots and spinal canal in its advanced stages. 10 Vargo and Flood 10 determined that the patient s normal sensory studies argued against any significant coexisting lower brachial plexopathy. In this present case report of a patient with a left C8 radiculopathy, a chest radiograph was performed to determine if a coexisting Pancoast tumor or other space-occupying lesion was present. There was no acute abnormality found on this patient s chest radiograph to suggest a Pancoast tumor. Treatment of relevant nerve roots involved in nerve sheath tumors has been studied by Celli. 1 The question involves whether to remove the nerve sheath tumor or preserve the nerve root. Surgery for the treatment of patients with spinal nerve sheath tumors can require complete resection of the nerve roots involved with the tumor. In this case report, a left C8 nerve root schwannoma was suspected following the CT of the cervical spine with myelogram. However, subsequent MRI imaging studies confirmed a left C7-T1 herniated disk without evidence of a schwannoma abnormality. However, the neurosurgeon did find a large disk herniation containing some disk material immediately anterior to the left C8 motor root that impinged directly on the motor root. The purpose of this resident s case problem was to provide an unusual presentation of a patient with a C8 radiculopathy without cervical or proximal upper quarter symptoms. The significance of this report illustrates the utility of a combination of physical examination, EMG and NCSs, and imaging in the diagnosis of a C8 radiculopathy in a patient presenting with forearm and hand symptoms, but without cervical or upper quarter pain. The positive findings on the physical examination and EMG examination, coupled with the normal NCSs of the left upper extremity, led to a diagnosis of a left C8 cervical radiculopathy. The left C8 cervical radiculopathy diagnosis was later supported by imaging studies and further substantiated during surgical exploration of the posterior cervical spine. more REFERENCES 1. Celli P. Treatment of relevant nerve roots involved in nerve sheath tumors: removal or preservation? Neurosurgery. 2002;51: ; discussion Czyrny JJ, Lawrence J. The importance of paraspinal muscle EMG in cervical and lumbosacral radiculopathy: review of 100 cases. Electromyogr Clin Neurophysiol. 1996;36: Dillingham TR, Lauder TD, Andary M, et al. Identification of cervical radiculopathies: optimizing the electromyographic screen. Am J Phys Med Rehabil. 2001;80: Dumitru D, Amato AA, Zwarts M. Electrodiagnostic Medicine. 2nd ed. Philadelphia, PA: Hanley and Belfus; Greathouse DG, Underwood FB, Tuttle P. Roth technique--a new approach for measuring sensory neural conduction in the median and ulnar nerves: suggestion from the field. Phys Ther. 1989;69: Kimura J. Electrodiagnosis in Diseases of Nerve and Muscle: Principles and Practice. 3rd ed. New York, NY: Oxford University Press; Levin KH, Maggiano HJ, Wilbourn AJ. Comparison of surgical and EMG localization of singleroot lesions. Neurology. 1996;46: Moore KL, Dalley AF. Clinically Oriented Anatomy. Baltimore, MD: Lippincott Williams & Wilkins; Netter FH. Atlas of Human Anatomy. 3rd ed. Teterboro, NJ: Icon Learning Systems; Vargo MM, Flood KM. Pancoast tumor presenting as cervical radiculopathy. Arch Phys Med Rehabil. 1990;71: information VIEW Videos on JOSPT s Website Videos posted with select articles on the Journal s website ( show how conditions are diagnosed and interventions performed. For a list of available videos, click on COLLECTIONS in the navigation bar in the left-hand column of the home page, select Media, check Video, and click Browse. A list of articles with videos will be displayed. journal of orthopaedic & sports physical therapy volume 40 number 12 december