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Poster 73: Inching Technique of Forearm Mixed Nerve Conduction Study in Traumatic Median Nerve Injury: A Case Report
ACADEMY ANNUAL ASSEMBLY ABSTRACTS
on his weight-lifting regimen and never again performing reverse curls. Assessment/Results: A magnetic resonance imaging of the right elbow showed edema in the brachioradialis and brachialis. Electrodiagnostic studies were notable for 3⫹ fibrillation potentials in the brachioradialis and brachialis muscles bilaterally. All other muscles tested (including other C5/6 muscles and others innervated by the radial and musculocutaneous nerves) showed no electrophysiologic abnormality. Nerve conduction findings, including musculocutaneous CMAP at the biceps and radial CMAP at the EIP, were normal. Conclusions: Cases of acute focal neuropathy have been reported in male weight lifters before. This case differs in that the patient had significant pain and only subtle weakness; other cases described significant and sudden weakness without associated pain. More importantly, the evidence of denervation in this case does not follow the distribution of a peripheral nerve or nerve root; rather, it is confined only to the 2 muscles specifically targeted by the performance of a novel exercise. This pattern of abnormality is indicative of significant local tissue damage, and it vividly illustrates the dangers of an overly aggressive weight-training regimen in the early adolescent age group. Key Words: Rehabilitation; Sports injuries; Weight lifting. Poster 71 Dermatonal Somatosensory Evoked Potentials Are Not Affected After Total C7 Nerve Surgical Transection in Humans. Annie Mar, MD (SUNY Upstate Medical University, Syracuse, NY); Robert Weber, MD. Disclosure: A. Mar, none; R. Weber, none. Objective: To study the correlation between somatosensory evoked potential (SEP) and sensory nerve conduction studies (SNAP) in human subjects with C7 nerve transection surgery. Design: SEPs are conduction studies of the pathway between the peripheral sensory nerve and the somatosensory cortex. At the peripheral sensory nerve level, SNAP are useful in assessing the amount of sensory fibers in relations to the SNAP amplitude. Based on reported studies, it is thought that the loss of 50% or less of axons of the peripheral sensory nerve do not affect SEP latency or waveform. 5 subjects with total C7 nerve transection surgery were studied. These subjects were patients with complete root avulsion lesions of the brachial plexus. The uninjuried C7 nerve from the contralateral plexus was transected and donated to the affected side. Compound SNAP was recorded before and after surgery on the donor side. Recordings were taken from digit 1 to 4 with median stimulation and from digit 4 and 5 with ulnar stimulation at the wrist. Cortical SEPs were recorded from stimulating these digits before and after surgery. Setting: Huashan Hospital, China. Participants: 4 men, 1 woman between the ages of 16 and 42. Results: In digit 1, SNAP amplitudes were reduced from 27% to 70% (mean, 50%). No notable changes were recorded at N20, the first cortical response. In digit 2 and 3, SNAP amplitudes were reduced from 62% to 85% (mean, 70%). No notable changes were recorded at N20. In digit 4, SNAP amplitudes were reduced from 36% to 60% (mean, 50%) with median nerve stimulation. SNAP amplitudes with ulnar stimulation were reduced in subjects 1 to 4 by 68%, 56%, 18%, and 20%, respectively. Subject 5 was not tested. No notable changes were recorded at N20. In digit 5, SNAP amplitudes were reduced by 53% in subject 1. No notable change was noted at N20. In subjects 2 to 4, there were no changes in SNAP or SEPs. Conclusions: A decrement of 70% or less in amplitude of SNAP, which roughly reflects the amount of axon loss, did not change the latency or waveform of the first cortical (N20) respons; and the present study does not support that dermatonal SEP to be useful in diagnosing C7 radiculopathy. Key Words: Rehabilitation.
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Poster 72 Guillain-Barre´ Syndrome With Severe Axonal Type Following Coccyx Revision Surgery: A Case Report. Cynthia L. Racine, MD (Rusk Institue of Rehabilitation, New York University Hospital, New York, NY). Disclosure: C.L. Racine, none. Setting: Tertiary care center. Patient: 23-year-old patient with left foot drop. Case Description: The patient has a history of multiple spine surgeries. The patient presented 1 week after coccyx revision surgery with gradual onset of weakness in all 4 extremities, blurry vision, and hoarse voice. Physical exam revealed areflexia, aphasia, facial muscle weakness, dysarthria, dysphasia, weak lateral gaze, mild shortness of breath, allodynia, and preserved sensation in the extremities. Manual muscle testing revealed 0/5 wrist and elbow flexors and extensors bilaterally, 2/5 hand grip, 1/5 wrist flexors, 0/5 knee extensors, EHL, and plantarflexors, 3/5 dorsiflexion, and 3/5 hip flexion bilaterally. Nerve conduction studies (NCS) showed absent response from the following sensory nerves on the left: sural, median, radial, and superficial peroneal. F waves of the median and ulnar motor nerves were absent. NCS of median and posterior tibial motor nerves showed greater than 50% drop in amplitude with low conduction velocities and increased onset latency. Ulnar and peroneal NCS on the left showed less than 50% drop in amplitude. Needle EMG revealed decreased recruitment in all muscles examined with fibrillation potentials in the left tibialis anterior and lumbar paraspinals. Assessment/ Results: 4 weeks after the onset of symptoms the patient had some functional gains and was able to eat and groom independently. She remained at Max Assist level for transfers and was unable to ambulate or transfer. Conclusions: This is an unusual case of Guillain-Barre´ syndrome (GBS) presenting with significant bulbar involvement. Rehabilitation professionals should be aware of the various presentations of GBS, including severe axonal forms with bulbar involvement, that may significantly impact prognosis. Key Words: Rehabilitation. Poster 73 Inching Technique of Forearm Mixed Nerve Conduction Study in Traumatic Median Nerve Injury: A Case Report. Peng Zhao, MD (Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY); Dennis D. Kim, MD; Se Won Lee, MD; Moo-Yeon Oh-Park, MD. Disclosure: D.D. Kim, none; S. Lee, none; M. Oh-Park, none; P. Zhao, none. Setting: Electrodiagnostic laboratory at a university hospital. Patient: 54-year-old man presented with severe sensation loss of the right hand after falling on his palm. Case Description: 54-year-old man fell on his right palm and immediately felt an electrical sensation radiate from the palm to middle finger. 3 months after the fall, no sensory nerve action potentials of right median nerve were seen on electrodiagnostics (antidromic recordings from all digits stimulated both at the wrist and midpalm). Compound muscle action potential of median nerve recorded on the right abductor pollicis brevis (APB) muscle was unobtainable with stimulation at the midpalm, wrist, and elbow. Mixed nerve conduction studies of the median nerve were performed by recording from the antecubital fossa and with serial stimulation at 1 cm intervals, starting 2cm proximal, and extending 3 cm distal to the wrist crease. Normal mixed nerve potentials were obtained with stimulation up to 1cm distal to wrist crease, however, no potential was obtained with stimulation more distally. Needle electromyography of the right APB muscle showed profuse denervation potentials without voluntary motor unit action potentials. Assessment/ Results: Findings from the inching technique of the forearm mixed nerve study suggests that the location of injury was between 1 to 2cm distal to wrist crease. Patient improved clinically after operative interArch Phys Med Rehabil Vol 89, November 2008
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ACADEMY ANNUAL ASSEMBLY ABSTRACTS
vention. Discussion: Normalized mixed nerve conduction studies of the forearm demonstrate an intact median nerve proximal to the wrist when routine sensory nerve and compound muscle action potentials are unobtainable from the hand. Application of the inching technique with serial stimulation at the wrist may further define the location of median nerve lesions. Conclusions: The inching technique in forearm mixed nerve conduction studies has a role in localizing severe traumatic median nerve lesions distal to the wrist. Key Words: Electrodiagnosis; Median nerve; Rehabilitation. Poster 74 Left Axillary and Suprascapular Nerve Damage Secondary to Herpes Zoster Infection: A Case Report. Adaku U. Nwachuku, DO (Nassau University Medical Center, East Meadow, NY); Ernesto Capulong, MD; Lyn Weiss, MD. Disclosure: E. Capulong, none; A.U. Nwachuku, none; L. Weiss, none. Setting: Outpatient rehabilitation clinic. Patient: 65-year-old man. Case Description: 65-year-old man presented with limited motion and weakness of the left shoulder. A month prior, he noted vesicular eruptions from the base of the neck to the lateral aspect of the left arm. He was diagnosed and treated for herpes zoster with Acyclovir. One week after treatment, he experienced pain and difficulty abducting his left upper extremity. Magnetic resonance imaging of the cervical spine and shoulder were negative. He was referred by his primary care physician for evaluation of his symptoms. Results: Physical exam showed an erythematous macular rash from the left upper thoracic paraspinals to the posterior and middle deltoid musculature, left middle and posterior deltoid atrophy, decreased sensation to light touch in the C5-T1 dermatome; limited active range of motion of left shoulder was as follows: abduction (25°) and forward flexion (20°). Manual muscle testing of deltoid and supraspinatus was 3/5. Deep tendon reflexes were intact. Electrodiagnositic studies were utilized to evaluate this patient’s weakness. Sensory nerve conduction studies were healthy. Motor nerve conduction studies showed abnormal conduction of the left axillary nerve and an unobtainable left suprascapular nerve response. Electromyography demonstrated acute denervation in the deltoid and supraspinatus muscles. There was increased irritability noted in the left biceps, triceps, and rhomboids. Cervical paraspinal muscles were normal. A diagnosis of left brachial plexopathy involving the left axillary and suprascapular nerves was made. The patient was managed with physical therapy and Medrol dose pack. He continues to follow up in outpatient clinic. Conclusions: Herpes zoster is a rare cause of axillary and suprascapular nerve palsy. In patients with zoster infection and shoulder weakness, zoster paresis should be considered. Key Words: Electrodiagnosis; Herpes zoster; Rehabilitation. Poster 75 Motor Cortex Hypoexcitability to Intraoperative Transcranial Electrical Stimulation in an Ambulatory Child With Prader-Willi Syndrome: A Case Report. Robert Rinaldi, MD (Children’s Mercy Hospitals and Clinics, Kansas City, MO). Disclosure: R. Rinaldi, none. Setting: Tertiary care pediatric hospital. Patient: 14-year-old female with Prader-Willi syndrome (PWS) and scoliosis. Case Description: The patient presented for surgical posterior spinal instrumentation and fusion of progressive scoliosis. Her preoperative functional status included ambulation for community distances, normal bowel and bladder function, and normative motor strength and sensation. She had a history of short stature and precocious puberty. Medications included human growth hormone and leuprolide. Her operative procedure included pedicle screw placement from T8 to L4, bilateral spine Arch Phys Med Rehabil Vol 89, November 2008
rod placement, and bone grafting. Anesthesia included induction with sevoflurane and maintenance with propofol and sufentanil. Intraoperative neurophysiologic monitoring included bilateral upper and lower extremity somatosensory evoked potentials (SSEP), bilateral upper and lower extremity transcranial electrical stimulation motor evoked potentials (TcMEP), and multilevel pedicle screw stimulation. Assessment/Results: TcMEP baselines were obtained but were unstable in the upper extremities, and were not obtained in the lower extemities. Upper and lower extremity SSEPs were obtained and remained stable throughout the surgical procedure with no significant changes in baseline latencies or amplitudes. Appropriate pedicle screw placement was verified by pedicle screw stimulation and imaging. Mean arterial pressures remained between 70 and 90mmHg. The patient’s physiologic parameters, core temperature, and blood volume loss remained stable during the procedure. Neurophysiologic monitoring equipment failure was ruled out as the cause of TcMEP absence. Conclusions: This is the first reported case, to our knowledge, of inability to acquire stable TcMEPs in an ambulatory patient with PWS despite stable SSEPs and intraoperative physiologic status. This correlates to recent studies demonstrating motor cortex hypoexcitability following transcranial magnetic stimulation in individuals with PWS. Intraoperative TcMEPs may be difficult to acquire in patients with PWS due to cortical hypoexcitability, and could dictate operative monitoring strategies and expectations. Key Words: Motor evoked potentials; PraderWilli syndrome; Rehabilitation. Poster 76 Myopathy With Rhabdomyolysis Induced by Concomitant Use of Cyclosporine and Simvastatin: A Case Report. Anupam Sinha, DO (Nassau University Medical Center, East Meadow, NY); Madhuri Dholakia, MD. Disclosure: M. Dholakia, none; A. Sinha, none. Setting: Inpatient medicine floor. Patient: 63-year-old man. Case Description: A patient with medical history of coronary artery disease, gout, hypercholesterolemia (on simvastatin therapy for 1 year), nephrotic syndrome (on cyclosporine therapy for 4 months), and lumbar herniated disks, was admitted to the hospital with the complaint of a 2-day history of new onset proximal muscle weakness, myalgia, and the inability to ambulate. Physical examination revealed decreased strength in the neck flexors and proximal upper and lower extremities, normative sensory examination, and normative reflexes. Laboratory studies showed normal complete blood count, creatine kinase (CK) of 8000, and erythrocyte sedimentation rate of 60. Nerve conduction study was unremarkable. Electromyography revealed no evidence of denervation potentials, however, myotonic discharges were seen in the proximal muscles of both upper and lower extremities. The patient was diagnosed with myopathy with rhabdomyolysis due to concomitant cyclosporine and simvastatin use. Assessment/ Results: Myalgia and a transient increase in the serum CK level is not unusual after treatment with statins. Fewer than 5% of treated patients have clinically overt myopathic symptoms. Studies have shown that coadministration of cyclosporine and lovastatin to patients with kidney transplants and hyperlipidemia increased the incidence of myopathy with rhabdomyolysis. We present a similar case with the use of cyclosporine and simvastatin, along with evidence of myopathic changes on electromyography. Conclusions: Physiatrists should be aware of the increased risk of statin-induced myopathy with concomitant cyclosporine therapy. Patients on statin and cyclosporine therapy who present with severe weakness should undergo electrodiagnostic studies to evaluate for myopathy, and have serum CK levels measured to evaluate for rhabdomyolysis. Key Words: Cyclosporine; Myopathy; Rehabilitation.
on his weight-lifting regimen and never again performing reverse curls. Assessment/Results: A magnetic resonance imaging of the right elbow showed edema in the brachioradialis and brachialis. Electrodiagnostic studies were notable for 3⫹ fibrillation potentials in the brachioradialis and brachialis muscles bilaterally. All other muscles tested (including other C5/6 muscles and others innervated by the radial and musculocutaneous nerves) showed no electrophysiologic abnormality. Nerve conduction findings, including musculocutaneous CMAP at the biceps and radial CMAP at the EIP, were normal. Conclusions: Cases of acute focal neuropathy have been reported in male weight lifters before. This case differs in that the patient had significant pain and only subtle weakness; other cases described significant and sudden weakness without associated pain. More importantly, the evidence of denervation in this case does not follow the distribution of a peripheral nerve or nerve root; rather, it is confined only to the 2 muscles specifically targeted by the performance of a novel exercise. This pattern of abnormality is indicative of significant local tissue damage, and it vividly illustrates the dangers of an overly aggressive weight-training regimen in the early adolescent age group. Key Words: Rehabilitation; Sports injuries; Weight lifting. Poster 71 Dermatonal Somatosensory Evoked Potentials Are Not Affected After Total C7 Nerve Surgical Transection in Humans. Annie Mar, MD (SUNY Upstate Medical University, Syracuse, NY); Robert Weber, MD. Disclosure: A. Mar, none; R. Weber, none. Objective: To study the correlation between somatosensory evoked potential (SEP) and sensory nerve conduction studies (SNAP) in human subjects with C7 nerve transection surgery. Design: SEPs are conduction studies of the pathway between the peripheral sensory nerve and the somatosensory cortex. At the peripheral sensory nerve level, SNAP are useful in assessing the amount of sensory fibers in relations to the SNAP amplitude. Based on reported studies, it is thought that the loss of 50% or less of axons of the peripheral sensory nerve do not affect SEP latency or waveform. 5 subjects with total C7 nerve transection surgery were studied. These subjects were patients with complete root avulsion lesions of the brachial plexus. The uninjuried C7 nerve from the contralateral plexus was transected and donated to the affected side. Compound SNAP was recorded before and after surgery on the donor side. Recordings were taken from digit 1 to 4 with median stimulation and from digit 4 and 5 with ulnar stimulation at the wrist. Cortical SEPs were recorded from stimulating these digits before and after surgery. Setting: Huashan Hospital, China. Participants: 4 men, 1 woman between the ages of 16 and 42. Results: In digit 1, SNAP amplitudes were reduced from 27% to 70% (mean, 50%). No notable changes were recorded at N20, the first cortical response. In digit 2 and 3, SNAP amplitudes were reduced from 62% to 85% (mean, 70%). No notable changes were recorded at N20. In digit 4, SNAP amplitudes were reduced from 36% to 60% (mean, 50%) with median nerve stimulation. SNAP amplitudes with ulnar stimulation were reduced in subjects 1 to 4 by 68%, 56%, 18%, and 20%, respectively. Subject 5 was not tested. No notable changes were recorded at N20. In digit 5, SNAP amplitudes were reduced by 53% in subject 1. No notable change was noted at N20. In subjects 2 to 4, there were no changes in SNAP or SEPs. Conclusions: A decrement of 70% or less in amplitude of SNAP, which roughly reflects the amount of axon loss, did not change the latency or waveform of the first cortical (N20) respons; and the present study does not support that dermatonal SEP to be useful in diagnosing C7 radiculopathy. Key Words: Rehabilitation.
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Poster 72 Guillain-Barre´ Syndrome With Severe Axonal Type Following Coccyx Revision Surgery: A Case Report. Cynthia L. Racine, MD (Rusk Institue of Rehabilitation, New York University Hospital, New York, NY). Disclosure: C.L. Racine, none. Setting: Tertiary care center. Patient: 23-year-old patient with left foot drop. Case Description: The patient has a history of multiple spine surgeries. The patient presented 1 week after coccyx revision surgery with gradual onset of weakness in all 4 extremities, blurry vision, and hoarse voice. Physical exam revealed areflexia, aphasia, facial muscle weakness, dysarthria, dysphasia, weak lateral gaze, mild shortness of breath, allodynia, and preserved sensation in the extremities. Manual muscle testing revealed 0/5 wrist and elbow flexors and extensors bilaterally, 2/5 hand grip, 1/5 wrist flexors, 0/5 knee extensors, EHL, and plantarflexors, 3/5 dorsiflexion, and 3/5 hip flexion bilaterally. Nerve conduction studies (NCS) showed absent response from the following sensory nerves on the left: sural, median, radial, and superficial peroneal. F waves of the median and ulnar motor nerves were absent. NCS of median and posterior tibial motor nerves showed greater than 50% drop in amplitude with low conduction velocities and increased onset latency. Ulnar and peroneal NCS on the left showed less than 50% drop in amplitude. Needle EMG revealed decreased recruitment in all muscles examined with fibrillation potentials in the left tibialis anterior and lumbar paraspinals. Assessment/ Results: 4 weeks after the onset of symptoms the patient had some functional gains and was able to eat and groom independently. She remained at Max Assist level for transfers and was unable to ambulate or transfer. Conclusions: This is an unusual case of Guillain-Barre´ syndrome (GBS) presenting with significant bulbar involvement. Rehabilitation professionals should be aware of the various presentations of GBS, including severe axonal forms with bulbar involvement, that may significantly impact prognosis. Key Words: Rehabilitation. Poster 73 Inching Technique of Forearm Mixed Nerve Conduction Study in Traumatic Median Nerve Injury: A Case Report. Peng Zhao, MD (Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY); Dennis D. Kim, MD; Se Won Lee, MD; Moo-Yeon Oh-Park, MD. Disclosure: D.D. Kim, none; S. Lee, none; M. Oh-Park, none; P. Zhao, none. Setting: Electrodiagnostic laboratory at a university hospital. Patient: 54-year-old man presented with severe sensation loss of the right hand after falling on his palm. Case Description: 54-year-old man fell on his right palm and immediately felt an electrical sensation radiate from the palm to middle finger. 3 months after the fall, no sensory nerve action potentials of right median nerve were seen on electrodiagnostics (antidromic recordings from all digits stimulated both at the wrist and midpalm). Compound muscle action potential of median nerve recorded on the right abductor pollicis brevis (APB) muscle was unobtainable with stimulation at the midpalm, wrist, and elbow. Mixed nerve conduction studies of the median nerve were performed by recording from the antecubital fossa and with serial stimulation at 1 cm intervals, starting 2cm proximal, and extending 3 cm distal to the wrist crease. Normal mixed nerve potentials were obtained with stimulation up to 1cm distal to wrist crease, however, no potential was obtained with stimulation more distally. Needle electromyography of the right APB muscle showed profuse denervation potentials without voluntary motor unit action potentials. Assessment/ Results: Findings from the inching technique of the forearm mixed nerve study suggests that the location of injury was between 1 to 2cm distal to wrist crease. Patient improved clinically after operative interArch Phys Med Rehabil Vol 89, November 2008
E44
ACADEMY ANNUAL ASSEMBLY ABSTRACTS
vention. Discussion: Normalized mixed nerve conduction studies of the forearm demonstrate an intact median nerve proximal to the wrist when routine sensory nerve and compound muscle action potentials are unobtainable from the hand. Application of the inching technique with serial stimulation at the wrist may further define the location of median nerve lesions. Conclusions: The inching technique in forearm mixed nerve conduction studies has a role in localizing severe traumatic median nerve lesions distal to the wrist. Key Words: Electrodiagnosis; Median nerve; Rehabilitation. Poster 74 Left Axillary and Suprascapular Nerve Damage Secondary to Herpes Zoster Infection: A Case Report. Adaku U. Nwachuku, DO (Nassau University Medical Center, East Meadow, NY); Ernesto Capulong, MD; Lyn Weiss, MD. Disclosure: E. Capulong, none; A.U. Nwachuku, none; L. Weiss, none. Setting: Outpatient rehabilitation clinic. Patient: 65-year-old man. Case Description: 65-year-old man presented with limited motion and weakness of the left shoulder. A month prior, he noted vesicular eruptions from the base of the neck to the lateral aspect of the left arm. He was diagnosed and treated for herpes zoster with Acyclovir. One week after treatment, he experienced pain and difficulty abducting his left upper extremity. Magnetic resonance imaging of the cervical spine and shoulder were negative. He was referred by his primary care physician for evaluation of his symptoms. Results: Physical exam showed an erythematous macular rash from the left upper thoracic paraspinals to the posterior and middle deltoid musculature, left middle and posterior deltoid atrophy, decreased sensation to light touch in the C5-T1 dermatome; limited active range of motion of left shoulder was as follows: abduction (25°) and forward flexion (20°). Manual muscle testing of deltoid and supraspinatus was 3/5. Deep tendon reflexes were intact. Electrodiagnositic studies were utilized to evaluate this patient’s weakness. Sensory nerve conduction studies were healthy. Motor nerve conduction studies showed abnormal conduction of the left axillary nerve and an unobtainable left suprascapular nerve response. Electromyography demonstrated acute denervation in the deltoid and supraspinatus muscles. There was increased irritability noted in the left biceps, triceps, and rhomboids. Cervical paraspinal muscles were normal. A diagnosis of left brachial plexopathy involving the left axillary and suprascapular nerves was made. The patient was managed with physical therapy and Medrol dose pack. He continues to follow up in outpatient clinic. Conclusions: Herpes zoster is a rare cause of axillary and suprascapular nerve palsy. In patients with zoster infection and shoulder weakness, zoster paresis should be considered. Key Words: Electrodiagnosis; Herpes zoster; Rehabilitation. Poster 75 Motor Cortex Hypoexcitability to Intraoperative Transcranial Electrical Stimulation in an Ambulatory Child With Prader-Willi Syndrome: A Case Report. Robert Rinaldi, MD (Children’s Mercy Hospitals and Clinics, Kansas City, MO). Disclosure: R. Rinaldi, none. Setting: Tertiary care pediatric hospital. Patient: 14-year-old female with Prader-Willi syndrome (PWS) and scoliosis. Case Description: The patient presented for surgical posterior spinal instrumentation and fusion of progressive scoliosis. Her preoperative functional status included ambulation for community distances, normal bowel and bladder function, and normative motor strength and sensation. She had a history of short stature and precocious puberty. Medications included human growth hormone and leuprolide. Her operative procedure included pedicle screw placement from T8 to L4, bilateral spine Arch Phys Med Rehabil Vol 89, November 2008
rod placement, and bone grafting. Anesthesia included induction with sevoflurane and maintenance with propofol and sufentanil. Intraoperative neurophysiologic monitoring included bilateral upper and lower extremity somatosensory evoked potentials (SSEP), bilateral upper and lower extremity transcranial electrical stimulation motor evoked potentials (TcMEP), and multilevel pedicle screw stimulation. Assessment/Results: TcMEP baselines were obtained but were unstable in the upper extremities, and were not obtained in the lower extemities. Upper and lower extremity SSEPs were obtained and remained stable throughout the surgical procedure with no significant changes in baseline latencies or amplitudes. Appropriate pedicle screw placement was verified by pedicle screw stimulation and imaging. Mean arterial pressures remained between 70 and 90mmHg. The patient’s physiologic parameters, core temperature, and blood volume loss remained stable during the procedure. Neurophysiologic monitoring equipment failure was ruled out as the cause of TcMEP absence. Conclusions: This is the first reported case, to our knowledge, of inability to acquire stable TcMEPs in an ambulatory patient with PWS despite stable SSEPs and intraoperative physiologic status. This correlates to recent studies demonstrating motor cortex hypoexcitability following transcranial magnetic stimulation in individuals with PWS. Intraoperative TcMEPs may be difficult to acquire in patients with PWS due to cortical hypoexcitability, and could dictate operative monitoring strategies and expectations. Key Words: Motor evoked potentials; PraderWilli syndrome; Rehabilitation. Poster 76 Myopathy With Rhabdomyolysis Induced by Concomitant Use of Cyclosporine and Simvastatin: A Case Report. Anupam Sinha, DO (Nassau University Medical Center, East Meadow, NY); Madhuri Dholakia, MD. Disclosure: M. Dholakia, none; A. Sinha, none. Setting: Inpatient medicine floor. Patient: 63-year-old man. Case Description: A patient with medical history of coronary artery disease, gout, hypercholesterolemia (on simvastatin therapy for 1 year), nephrotic syndrome (on cyclosporine therapy for 4 months), and lumbar herniated disks, was admitted to the hospital with the complaint of a 2-day history of new onset proximal muscle weakness, myalgia, and the inability to ambulate. Physical examination revealed decreased strength in the neck flexors and proximal upper and lower extremities, normative sensory examination, and normative reflexes. Laboratory studies showed normal complete blood count, creatine kinase (CK) of 8000, and erythrocyte sedimentation rate of 60. Nerve conduction study was unremarkable. Electromyography revealed no evidence of denervation potentials, however, myotonic discharges were seen in the proximal muscles of both upper and lower extremities. The patient was diagnosed with myopathy with rhabdomyolysis due to concomitant cyclosporine and simvastatin use. Assessment/ Results: Myalgia and a transient increase in the serum CK level is not unusual after treatment with statins. Fewer than 5% of treated patients have clinically overt myopathic symptoms. Studies have shown that coadministration of cyclosporine and lovastatin to patients with kidney transplants and hyperlipidemia increased the incidence of myopathy with rhabdomyolysis. We present a similar case with the use of cyclosporine and simvastatin, along with evidence of myopathic changes on electromyography. Conclusions: Physiatrists should be aware of the increased risk of statin-induced myopathy with concomitant cyclosporine therapy. Patients on statin and cyclosporine therapy who present with severe weakness should undergo electrodiagnostic studies to evaluate for myopathy, and have serum CK levels measured to evaluate for rhabdomyolysis. Key Words: Cyclosporine; Myopathy; Rehabilitation.