anterior and posterior. Extensor hallucis longus showed novoluntary motor activity. Biceps femoris (both heads) andgluteus maximus were normal; gluteus medius normal ex-cept for unsustained increased insertional activity. Right kneeMRI revealed changes consistent with acute and chronicdenervation in semimembranosus, tibialis anterior, lateralgastrocnemius (acute only), extensor digitorum longus andperoneus longus, but normal biceps femoris, with normal-appearing sciatic and deep peroneal nerves.Discussion: Discretely non-uniform sciatic nerve injuryaffecting the peroneal and tibial nerves distal to the fibularhead appears to be the main cause of the clinical presenta-tion. Also present is some proximal sciatic denervation onMRI, mild lumbosacral polyradiculopathy and sensory poly-neuropathy.Conclusions: This patient’s foot drop has a proximalcause, yet undetermined. Pelvic imaging may elucidate thediagnosis.Keywords: Electrodiagnosis, Gait, Drop foot, Sciatic neu-ropathy.

Poster 86

NCS/EMG Consistent with MonomelicAmyotrophy in a Patient Previously Diagnosedwith Left Ulnar Neuropathy: A Case Report.Alexis A. Tracy, DO (University of Wisconsin, Madi-sion, WI).

Disclosures: A. A. Tracy, None.Patients or Programs: A 29-year-old male bodybuildercomplaining of left grip weakness and hand numbness.Program Description: The patient presented with leftgrip weakness, noted while lifting weights, intermittentnumbness in 4th and 5th digits and dorsum of the left hand,and tremor in the left upper limb for 6 months. He deniedany symptoms in the right upper limb or lower limbs. Phys-ical examination revealed a very muscular appearing malewith weakness in the ulnar-innervated intrinsic muscles ofthe left hand. There is notable atrophy in these muscles whencompared to the right. He also had decreased sensation to pinprick and light touch in the ulnar distribution of the lefthand. The rest of his examination is unremarkable. MRI ofcervical spine was noncontributory. The patient underwent 2previous EMGs, the first interpreted as consistent with CTSand the second as consistent with a C8, T1 radiculopathy.The patient appeared to have a left ulnar neuropathy from aclinical standpoint and was set up for a repeat EMG in hopesof isolating the neuropathy for possible surgical referral.Setting: University outpatient EMG clinic.Results: The patient’s NCS/EMG revealed findings consis-tent with anterior horn cell disease and cervical polyradicu-lopathy at the C7, C8, and T1 levels, which was chronic,active, and severe. There was no electrodiagnostic evidencefor a focal neuropathy in the left upper limb. These findingsare consistent with monomelic amyotrophy.Discussion: Monomelic amyotrophy is a very rare neuro-muscular disease affecting anterior horn cells. It is character-

ized by weakness and atrophy in a single limb. It occurs inmales over females (10:1), usually between the ages of 15-25years. Typical NCS/EMG findings include chronic denerva-tion in 100% of cases and acute denervation in 45% of casesin the affected limb, C7, C8, and T1 being the most com-monly affected. CMAPs may be small in the affected limb,usually in the ulnar nerve. Sensory studies are normal. Dis-ability is generally slight. Rarely, the disease may progress toALS.Conclusions: NCS/EMG is helpful in differentiating aseemingly clear focal ulnar neuropathy from a rare anteriorhorn cell disease.Keywords: Rehabilitation, Electrodiagnostic medicine,Monomelic amyotrophy, Anterior horn cell disease.

Poster 87

Normative Sensory Nerve Conduction Valuesof the Deep Fibular Nerve: TechnicalDescription of a New Orthodromic Technique.Eric Watson, DO (Central Coast Musculoskeletaland Neurological Rehabilitation, Santa Maria,CA); Jeffrey A. Strommen, MD.

Disclosures: E. Watson, None.Objective: To collect demographic and sensory nerve ac-tion potential (SNAP) data of the deep fibular nerve (DFN)using an orthodromic technique in normal subjects across arange of age groups, and to determine reproducibility andreliability.Design: Record DFN compound muscle action potentials(CMAP) and superficial fibular nerve (SFN) SNAPs as con-trols. Record DFN SNAPs from technique found in pilotstudy with electrode location confirmed by ultrasonography.We established user-friendly landmarks as a recording site(the stimulation site of EDB CMAP) and a stimulation site (1cm lateral to EHL tendon), as well as employing an ortho-dromic approach.Setting: Tertiary medical center.Participants: 60 male/female participants ages 18-60 yearswith exclusion criteria of subjective numbness in the feet,history of lumbar surgery, neurologic conditions affectingperipheral nerves, ankle surgery/trauma, and DM.Interventions: Not applicable.Main Outcome Measures: Descriptive statistics in-clude the mean, standard deviation (SD), median, and rangefor peak amplitude (amp), distal latency (DL), and conduc-tion velocity (CV) overall.Results: The data included bilateral assessment of 56 nor-mal participants (37 female, 19 male), with mean age 40.1years (range 18-59), and a SD of 11.5 years. Inter- andintra-rater reliability calculations were acceptable with lim-ited exceptions. The mean amps of the right/left DFN SNAPswere 8.29/8.51 (ranges 2-25/1-21) �V, and SD of 5.48/4.91.The mean DLs of the right/left DFN SNAPs were 2.34/2.35(ranges 2-2.7/2-2.8) ms, and SD of 0.19/0.16. The mean CVsof the right/left DFN SNAPs were 46.44/46.81 (ranges 38-57/35-57) m/s, and SD of 4.48/4.78. The absent response rate

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found in our study, 3.6%, is less than that in an anatomicstudy which found an absent medial terminal branch of theDFN in 8.3%.Conclusions: Sensory nerve conduction studies of theDFN typically result in wide variation, low amplitudes, andfrequently encountered absent responses. These results arenot thought to be clinically useful. In our study, we present anew technique to assess the SNAP of the DFN at the anklewhich consistently produces waveforms with higher ampli-tudes. Clinical application to be discussed.Keywords: Rehabilitation, Electrodiagnosis, Fibular nerve,Nerve conduction.

Poster 88

Persistent Brachial Plexus Injury afterCoronary Artery Bypass Surgery: A CaseReport.Meghan A. Magill, DO (Loyola University HealthCenter, Maywood, IL); Sung Ahn, DO.

Disclosures: M. A. Magill, None.Patients or Programs: A 60-year-old man, status post 3vessel coronary artery bypass graft (CABG).Program Description: The patient is status post CABG inJuly 2007, during which the internal mammary artery andsaphenous vein were harvested. Postoperatively, he com-plained of persistent right upper extremity weakness andnumbness. Examination by the physiatrist revealed atrophyof the first web space and decreased sensation of the rightmedial forearm and all fingers. Manual muscle testing of theupper extremity showed asymmetric weakness in the rightthumb adduction and opposition, finger flexion, wrist exten-sion and flexion, and elbow extension. Reflexes were absentbilaterally. He was referred for electrodiagnostic testing.Setting: Outpatient clinic, VA hospital.Results: Nerve conduction studies of the bilateral upperextremities showed absent right medial antebrachial sensoryresponse, while the left side showed 15.7 �V amplitude atpeak of 2.4 ms. There was significantly lower right medianmotor amplitude compared to the left. Needle examinationshowed abnormalities predominantly in the right lowertrunk innervated muscles. The results are consistent with achronic right lower trunk brachial plexopathy, superim-posed on generalized peripheral neuropathy.Discussion: Brachial plexus injury associated with CABGis not uncommon; however, it is generally transient. Harvest-ing of the internal mammary artery increases the risk forbrachial plexus injury. Other mechanisms of injury includepoor positioning, clavicular and first rib fracture, jugular veincannulation and asymmetric retraction of the sternal halves.The root levels C7-T1 are most commonly involved, present-ing as a lower trunk plexopathy.Conclusions: Physicians should be aware of the potentialfor peripheral nerve injury after CABG and inform patients ofthe risk. Patients with complaints of weakness and paresthe-sia after surgery may benefit from electrodiagnostic testing.

Keywords: Electrodiagnosis, Brachial plexus, Coronary ar-tery bypass.

Poster 89

Progressive Paresthesias Secondary toPosterior Femoral Cutaneous Neuropathy: ACase Report.Bruce H. Hsu, Doctor of Medicine (Thomas Jeffer-son University Hospital, Philadelphia, PA); CarolynForsman, MD; Channarayapatna R. Sridhara, MD;Michael Weinik, DO.

Disclosures: B. H. Hsu, None.Patients or Programs: A 46-year-old man with progres-sive paresthesias of the buttock and posterior thigh on leftmore than right side.Program Description: Patient referred to electrodiag-nostic center with a history of 3 years of worsening posteriorthigh and buttock numbness, starting at the left ischial tuber-osity with radiation distally on left posterior thigh, whicheventually interfered with functional sitting at work. MRIrevealed a small annular tear in the central posterior disk atL4-L5 and a small central tear on right with posterolateraldisk protrusion at L5-S1 without nerve root impingement.Clinical sensory examination was consistent with patchynumbness in the left posterior femoral cutaneous nerve dis-tribution. Electrodiagnostic examination revealed a pro-longed distal sensory latency in the left posterior femoralcutaneous nerve compared to the right femoral cutaneousnerve with symmetrical amplitude of the sensory nerve ac-tion potential.Setting: Tertiary rehabilitation center outpatient electrodi-agnostic laboratory.Results: Detection of posterior femoral cutaneous neurop-athy can be achieved through the use of sensory nerve con-duction studies, using a technique developed by Dumitruand Nelson.Discussion: A literature review revealed that posterior fem-oral cutaneous neuropathy is a rare entity which may becaused by compression of the nerve either as a function ofsitting or venous plexus dysfunction surrounding the nerveat the region of the gluteal folds. Through the use of preciseclinical examination and electrodiagnostic sensory nerveconduction studies, this entity can be diagnosed and treatedappropriately.Conclusions: Posterior femoral cutaneous neuropathy is arare entity which may result in paresthesias that interferewith functional sitting and may mimic an S2 radiculopathy.Early identification with appropriate electrodiagnostic studyand referral for further evaluation using ultrasound imagingto identify potential venous plexus dysfunction as an under-lying etiology may help direct appropriate treatment.Keywords: Rehabilitation, Neuropathy, Electrodiagnosticmedicine.

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