PE Class
CTS
EMG
Anatomy
M&M
100
A 35-year-old office worker presents with 1 week of right neck and upper limb pain that radiates down her arm and forearm to her long finger. She does not remember any inciting trauma or exertion associated with the onset of her symptoms. Her biceps reflex is preserved and the triceps reflex is diminished in the affected arm. Which nerve root is most likely affected? a) C5 b) C6 c) C7 d) C8
Answer: C The C7 root is the most likely affected nerve root in this case, since the biceps reflex is preserved and the triceps reflex is diminished, and the patient’s pain radiates into the long finger. A history of trauma or physical exertion preceding the onset of symptoms occurs in less than 15% of patients
100
A patient presents to your clinic with a 1-month history of mild hand numbness and clumsiness without weakness. Electrodiagnosis confirms a primarily sensory median neuropathy at the wrist without axon loss. Symptoms are not interfering with work. What is the most appropriate treatment recommendation to provide short-term relief for this patient? (a) Immediate referral to surgery for carpal tunnel release (b) Neutral wrist splints to be worn at night (c) Thumb spica splint (d) Injection of platelet rich plasma into carpal tunnel
Answer (b) Wrist splints are shown to effectively decrease symptoms of carpal tunnel syndrome in the short-term. Splints should be worn at night and during the day if possible. Brace should place wrist in neutral (up to 5o of extension): note that many off-the-shelf carpal tunnel braces place the wrist in excessive extensions. A thumb spica splint is not effective in treating carpal tunnel syndrome. Conservative treatment is essential in mild to moderate cases of carpal tunnel syndrome. Surgical referral should be considered for patients with weakness or worsening symptoms not improved with conservative treatment. Platelet rich plasma injections are not an effective treatment for carpal tunnel syndrome.
100
Which of the following would be expected in a C5 radiculopathy? A. Reduced ulnar compound muscle action potential to the abductor little finger. B. Positive waves in the pronator quadratus. C. Reduced median sensory nerve action potential amplitude to the thumb. D. Positive waves in the brachioradialis. E. Positive waves in the latissimus dorsi.
Answer: D The brachioradialisis innervated by the C5 and C6 nerve roots through the posterior cord of the brachial plexus and radial nerve. The C5 nerve root does not contribute fibers to the ulnar nerve. Neither pronator quadratus (C7-8, T1) nor latissimus dorsi (C6-8) get any supply from C5. C6 provides the sensory innervation to the thumb via the median nerve, but sensory nerve conduction studies are expected to be normal in a radiculopathy due to the preganglionic anatomic location of the lesion.
100
Which one of the following muscles would be abnormal in a C8 radiculopathy? A. Infraspinatus. B. Pronator teres. C. Flexor carpi ulnaris. D. Serratus anterior. E. Brachioradialis.
Answer: C The flexor carpi ulnaris is the only muscle listed with C8 innervation. The infraspinatus and brachioradialis have C5-6 innervation, the serratus anterior has C5-7 innervation, and the pronator teres has C6-7 innervation.
100
Overuse syndromes resulting in tendinopathies are ideally treated differently in the progressive phases of recovery. Treatments for tendinopathies may appropriately be initiated in the following order: a) relative rest, stretching, muscle activation, strengthening. b) massage, relative rest, strengthening, muscle activation. c) aggressive stretching, relative rest, muscle activation, strengthening. d)ice, strengthening, muscle activation, stretching.
Answer: A The first goal is to reduce inflammation and irritation. Rest, nonsteroidal anti-inflammatory agents, and ice each help accomplish that first goal. Aggressive stretching of sore muscles does not accomplish the first goal of reducing inflammation and irritation. Strengthening should not begin until pain is controlled and stretching is tolerated without pain. Muscle activation refers to techniques designed to elicit specific muscles within a functional muscular complex that may not be efficiently contracting in response to neural excitation.
200
A patient presents to your clinic with right distal upper extremity weakness. Electrodiagnostic studies are suggestive of a posterior interosseous neuropathy. This diagnosis is most consistent with which of the following clinical examination findings? A. Weakness with forearm pronation. B. Weakness with index finger extension. C. Decreased sensation over dorsum of the hand. D. Weakness with elbow extension. E. Weakness with wrist flexion.
Answer: B A posterior interosseous neuropathy typically is a pure motor neuropathy involving the radial nerve. It usually occurs as an entrapment neuropathy under the tendinous arcade of Frohse. Elbow extension and the superficial radial nerve would be spared.
200
Which statement about carpal tunnel syndrome is TRUE? (a) A prolonged median motor distal latency is mandatory for diagnosis. (b) Symptoms improve after splinting the wrist in flexion for 2 weeks. (c) X-ray and magnetic resonance imaging studies have been standardized for diagnosis. (d) The syndrome is a complex of numbness and pain in a median nerve distribution.
Answer: D Carpal tunnel syndrome is a symptom complex that includes numbness, tingling, and pain in a median nerve distribution. Although objective testing such as nerve conduction studies can help confirm the diagnosis, evaluation must include the patients’ symptoms. Magnetic resonance imaging and ultrasound measurements will likely add objective evidence to help confirm the diagnosis, although standards are not in place at this time. Symptom reduction may occur after splinting in neutral, but is not diagnostic.
200
Which statement about the median nerve is true? A. Routine median motor NCSs are abnormal in upper trunk brachial plexopathies. B. Median sensory NCSs to the index finger are typically normal in lower trunk brachial plexopathies. C. The anterior interosseous nerve branches proximal to the pronator teres muscle. D. The nerve can be compressed at the Arcade of Frohse. E. The nerve is commonly affected in posterior cord brachial plexopathies.
Answer: B In lower trunk brachial plexopathies the median sensory fibers are spared because they travel through the upper trunk, thus the median sensory nerve conduction studies would be normal. The median motor fibers to the abductor pollicis brevis travel through the lower trunk, thus the motor nerve conduction studies are normal in upper trunk lesions. Nerve fibers contributing to the median nerve do not traverse the posterior cord. The anterior interosseous nerve branches distal to the pronator teres. The radial nerve can be compressed at the Arcade of Frohse.
200
The anterior interosseous nerve innervates which muscle? a) Brachioradialis b) Extensor indicis proprius c) Extensor hallucis longus d) Pronator quadratus
Answer: D The pronator quadratus, flexor pollicis longus, and the lateral half of flexor digitorum profundus are innervated by the anterior interosseous nerve. The brachioradialis is innervated by the radial nerve, the extensor indicis proprius by the posterior interosseous nerve, and the extensor hallucis longus by the deep peroneal nerve.
200
A 45 year-old concert violinist presents to your clinic for evaluation of left elbow pain. She has been diagnosed with “lateral epicondylitis” and has had pain and impaired function for 8 months. She has been treating her symptoms with relative rest, occupational therapy and alternative therapies, such as acupuncture and massage, without improvement in her symptoms. What other diagnoses should you consider in this patient? (a) Intersection syndrome (b) Musculocutaneous neuropathy (c) Posterior interosseous neuropathy (d) Rotator cuff tendinopathy
Answer: C Patients whose symptoms are consistent with lateral epicondylitis or “tennis elbow” but who do not respond to conservative treatments should be considered to have a posterior interosseous neuropathy. Mild neural compression of the posterior interosseous nerve may present with proximal and dorsal forearm pain without obvious muscle weakness, wasting, or sensory deficits.
300
A 40-year-old man sustained an injury to his left arm, 3 weeks ago, when he lost his balance and crashed into a bookshelf. His complaints include left arm pain, weakness with extension of his wrist and fingers, and decreased hand grip. He denies any numbness but has odd sensations over the dorsum of the left hand. Prior to any testing, which problem would you consider as the most likely? (a) Posterior interosseous neuropathy (b) C7 radiculopathy (c) Posterior cord brachial plexopathy (d) Radial neuropathy
Answer: D The clinical presentation, radial nerve injury is the most likely cause of the patient’s symptoms. Considering the location of the trauma the other possibilities seem less likely. In a posterior interosseous nerve injury one would not expect any sensory problems.
300
Which non-surgical treatment for carpal tunnel syndrome is shown to provide significant short-term benefit? (a)Magnet therapy (b)Laser therapy (c)Therapeutic exercise (d)Therapeutic ultrasound
Answer: (d) Patients suffering from carpal tunnel syndrome are often offered nonsurgical treatments. Current evidence shows significant benefit from therapeutic ultrasound treatments, splinting, yoga, and carpal bone mobilization. However, trials involving the use of magnet therapy, laser therapy, therapeutic exercise, and chiropractics have not produced significant benefits compared to placebo or control treatments.
300
A 36-year-old female changed job positions at her place of employment and is now performing more keyboard work. She has developed left forearm cramping and weakness, especially complaining of difficulty lifting her wrist. Her left arm nerve conduction studies (NCSs) revealed normal median, ulnar, and radial sensory conduction studies. The left median and ulnar motor NCSs were normal. On needle electromyography (EMG), she has normal findings in the left deltoid, triceps, biceps, first dorsal interosseous, and abductor pollicis brevis. Which of the following is correct? A. No further NCS/needle EMG assessments are needed. B. Repetitive stimulation studies are needed. C. Needle EMG assessment of the left extensor digitorum communis is needed. D. Needle EMG assessment of the left brachialis will be abnormal. E. Needle EMG assessment of the right arm is needed.
Answer: C The patient needs to be assessed for posterior interosseous syndrome. The posterior interosseous nerve supplies the extensor digitorum communis, but not the brachialis. The radial nerve sensory conduction study will be normal as will assessment on the triceps on needle electromyography
300
When performing electromyography, which of the following muscles is helpful in differentiating an uppertrunk brachial plexus injury from a cervical radiculopathy? a) biceps brachii b) deltoid c) rhomboid d) supraspinatus
Answer: C The rhomboid muscles are innervated by the dorsal scapular nerve and arise from the C4-C5 roots. Thedorsal scapular nerve arises proximal to the upper trunk of the brachial plexus. The muscles areinfrequently sampled when performing the needle examination, however, findings in the rhomboids mayhelp differentiate a cervical radiculopathy (C4-C5) from a more distal upper trunk brachial plexopathy.The biceps brachii is innervated by the C5-6 roots and the musculocutaneous nerve (MCN). The MCN isa terminal branch from the lateral cord of the brachial plexus. The triceps muscles are innervated by theC6-C7-C8 roots and radial nerve(RN). The radial nerve is a terminal branch from the posterior cord of thebrachial plexus. The supraspinatus muscle is innervated by the C5-6 roots and the suprascapular nerve(SN). The SN is a branch off of the upper trunk of the brachial plexus.
300
Following a crush injury with axonotmesis, the approximate growth regeneration rate at the wrist is 1 centimeter per (a) day. (b) week. (c) month. (d) year.
Answer: B Regenerating axons grow approximately 1 millimeter a day, 1 centimeter a week, 1 inch a month, or 1 foot a year. The rate of axon regeneration depends chiefly on type of injury (crush or laceration) and whether thelesion is proximal or distal. Growth rate following a crush injury with axonotmesis in the upper arm is about 8 millimeters a day; in the upper forearm it is about 6 millimeters a day, at the wrist about 1-2 millimeters a day, and in the hand about 1.0-1.5 millimeters a day. Easier figures to remember, however, are 1mm/day, 1cm/week, or 1 inch/month.
400
A gymnast is experiencing ulnar-sided wrist pain that is exacerbated by forearm rotation. Physical exam of the painful wrist suggests greater distal radius palmar-dorsal movement relative to the ulna compared to the other wrist, suggesting distal radioulnar joint laxity. You suspect she has a) a scaphoid fracture. b) De Quervain syndrome. c) a pulley injury. d) a triangular fibrocartilage complex tear
Answer: D The triangular fibrocartilage complex (TFCC) is a stabilizer of the distal radioulnar joint (DRUJ). Athletes who participate in repetitive loading of the wrist may be susceptible to degenerative changes, or a fall on an outstretched arm can cause acute injuries. Scaphoid fractures typically present with dull and aching pain in the anatomic snuffbox at the radial wrist. De Quervain syndrome refers to tenosynovitis of the abductor pollicis longus and extensor pollicis brevis, and it presents with pain over the radial styloid. It often occurs in racquet sport athletes. Pulley injuries most often occur in climbers, and presents with pain over the volar aspect of the phalanx.
400
A 45-year-old secretary comes in complaining of right hand numbness that began 6 weeks ago, and her symptoms are beginning to bother her at night. After performing a physical exam you diagnose her with carpal tunnel syndrome. Which treatment is shown to improve the symptoms of carpal tunnel syndrome for up to 1 year? (a) Oral corticosteroids (b) Therapeutic ultrasound (c) Wrist/hand splint (d) Tendon glide maneuvers
Answer: C Using a wrist/hand splint can improve the symptoms of carpal tunnel syndrome for up to 1 year. Therapeutic ultrasound and oral corticosteroids have been shown to provide only short-term relief. Tendon glide maneuvers have not been shown to affect the outcome of carpal tunnel syndrome.
400
The findings of decreased abductor pollicis brevis and abductor digiti minimi compound muscle action potential amplitude, abnormal ulnar sensory nerve action potential (SNAP) amplitude, and normal median SNAP amplitude are most consistent with which of the following? A. Neurogenic thoracic outlet syndrome. B. Ulnar nerve elbow segment neuropathy. C. Ulnar compression at the elbow and median compression at the ligament of Struthers. D. Median SNAP amplitude recording from the middle finger. E. C8 cervical radiculopathy.
Answer: A Neurogenic thoracic outlet syndrome is caused by compression of the lower trunk of the brachial plexus. Nerve conduction abnormalities found in these patients consist of reduced or absent ulnar sensory nerve action potentials (SNAPs) and decreased compound muscle action potentials of the abductor pollicis brevis and ulnar intrinsic hand muscles when compared with the normal side. In middle trunk plexopathy, median SNAPs are usually abnormal as well.
400
Following repair of a right distal biceps tendon rupture, a 31-year-old construction worker presents with problems extending his fingers. He had noticed swelling in the arm and forearm before his cast was removed about 4 weeks ago. He does not have any sensory complaints and the right superficial radial sensory nerve action potential is normal. Needle exam shows these data: R Triceps 0 Normal R Biceps 0 Normal R Brachioradialis 0 Normal R Extensor digitorum communis 2+ Reduced R Extensor indicis proprius 2+ Reduced R Flexor carpi ulnaris 0 Normal R 1st dorsal interosseous 0 Normal R Extensor carpi radialis 0 Normal R Supraspinatus 0 Normal R Cervical paraspinals 0 -- This patient most likely has a right (a) radial mononeuropathy at the elbow. (b) posterior interosseous neuropathy. (c) posterior cord plexopathy. (d) C7 and/or C8 radiculopathy.
Answer: B The electrophysiologic findings are consistent with involvement of the right posterior interosseous nerve (PIN). Typically in PIN injuries the triceps, brachioradialis, and extensor carpi radialis longus/brevis muscles are spared.
400
A 25 year old patient presents for electrodiagnostic testing after sustaining a right shoulder injury following a motorcycle crash 4 weeks ago. He has no active elbow, wrist or finger extension. The needle examination of the radial innervated muscles shows normal insertional activity, no abnormal spontaneous activity and absent motor recruitment. In the Sunderland classification system, this nerve injury is best described as? a) myelin injury with no Wallerian degeneration b) Wallerian degeneration with preservation of endoneurium c) disruption of axon with intact perineurium d) complete discontinuity of the nerve
Answer: A The injury described is limited to the myelin with preservation of the axon. This type of injury is classified as neurapraxia by the Seddon classification and as type 1 by the Sunderland classification. In axonal injury, one would typically observe positive sharp waves and fibrillation potential within 3 weeks after the injury. Sunderland type 2 and 3 are both forms of axonal injury and differ in their extent of injury to the supporting neural structures. Sunderland type 2 and 3 are classified as axonotmesis by the Seddon classification. Complete discontinuity of the nerve is classified as type 5 Sunderland and as neurotmesis by Seddon
500
A 48-year-old railroad conductor has difficulty using his ticket puncher with his right hand. He has no sensory signs or symptoms. Examination demonstrates weakness of the adductor pollicis, first dorsal interosseous, but not abductor digiti quinti muscles. Other muscles examined in the right hand and arm are normal. What is the most likely diagnosis? A. Anterior interosseous nerve lesion. B. Posterior interosseous nerve lesion. C. Ulnar nerve lesion at the elbow. D. Ulnar nerve lesion at the wrist. E. Medial cord brachial plexus lesion.
Answer: D The ulnar nerve enters the hand through Guyon’s canal at the wrist, which can be a site of ulnar nerve compression and neuropathy. Sensory impairment, if present, spares the dorsum of the hand innervated by the dorsal cutaneous branch, which arises proximal to the wrist. The lesion at the wrist affects the ulnar-innervated hand muscles. The deep and superficial branch of the ulnar nerve may be affected. In this example, the deep branch is selectively affected because of the repetitive recurrent pressure from the ticket puncher. Involvement of the superficial branch results in weakness of the palmaris brevis muscle and loss of sensation in the little fingerand ulnar half of the ring finger. Ulnar lesions at the elbow affect the dorsal ulnar cutaneous nerve and may involve the flexor carpi ulnaris and ulnar half of flexor digitorum profundus muscle. Anterior interosseous nerve lesions affect the flexor pollicis longus, radial half of the flexor digitorum profundus, and pronator quadrates muscles. Posterior interosseous nerve lesions affect radial-innervated muscles distal to the supinator. Medial plexus lesions affect the lower trunk and would also affect the median-innervated hand muscle
500
Which of the following muscles is most commonly innervated by the cross-over in Martin–Gruber anastomosis? A. The first dorsal interosseous. B. The flexor carpi ulnaris. C. The adductor digiti minimi. D. The adductor pollicis. E. The opponens pollicis.
Answer: A This common anatomical variant is cited in multiple studies and summarized in the reference. When present it refers to a branch from the median nerve (usually traveling with the anterior interosseous branch of the median nerve) to the ulnar nerve in the forearm carrying motor nerve fibers to muscles in the hand that are normally innervated by the ulnar nerve. When a Martin-Gruber anastomosis (MGA) is present, these fibers pass through the arm and proximal forearm in the median nerve until they cross to the ulnar nerve in the MGA in the forearm. Fibers in a MGA do not innervate the flexor carpi ulnaris muscle. The opponens pollicis and abductor pollicis brevis muscles are sometimes discussed with MGA because compound muscle action potentials of these muscles appear to be larger with elbow than wrist stimulation because of summation from adductor pollicis with elbow, but not wrist, stimulation when a MGA is present. Type 1 involves the hypothenar muscles and is suspected following routine conductions because ofa drop in the proximal amplitude not caused by submaximal stimulation at the elbow. Type II is the most common and involves the first dorsal interosseous.
500
A 45-year-old male is referred for EDX examination after a 2-month complaint of arm pain and weakness, which began when he woke up one morning and had a severe pain over his left shoulder region. This pain persisted for 3-4 days and then resolved. Subsequently, he noted weakness while using his left arm and hand. Overall, he believes his symptomatology has not changed within the past 2-3 weeks. On neuromuscular examination, there appears to be mild weakness of the left deltoid, as well as mild winging of the left scapula when the arm is abducted forward. Deep tendon reflexes appear mildly reduced in the left upper extremity compared to the right. There is reduced sensation over the left thumb. On nerve conduction studies for this patient, the median sensory nerve action potential (SNAP) on the left side has a markedly reduced amplitude with a normal conduction velocity and distal latency. The median compound muscle action potential (CMAP), ulnar CMAP, and SNAP are all entirely normal. Which is the most likely explanation? A. Incidental carpal tunnel syndrome. B. Lower trunk brachial plexopathy. C. C8 radiculopathy. D. Lateral cord plexopathy. E. Medial cord plexopathy.
Answer: D A lateral cord plexopathy, D, the correct choice, would result in a decreased median sensory nerve action potential (SNAP) amplitude since the median sensory fibers run through the lateral cord. Lower trunk or medial cord brachial plexopathy, choices Band E, would result in decreased ulnar SNAP amplitude and decreased median and ulnar compound muscle action potential amplitude over the hand muscles. In carpal tunnel syndrome, choice A, the expected abnormality is increased median distal latency. A C8 radiculopathy, choice C, is a preganglionic lesion (proximal to the dorsal root ganglion) and would not explain the abnormal median sensory response
500
An electrodiagnostic study shows significantly reduced ulnar sensory amplitude along with some reduction of the ulnar compound muscle action potential amplitude. The medial antebrachial sensory and median motor responses were normal. On needle examination, neurogenic changes were seen in the first dorsal interosseous, flexor carpi ulnaris, flexor digitorum profundus, extensor indicis proprius, extensor carpi ulnaris and flexor pollicis longus. These findings are most consistent with the diagnosis of: A. Ulnar neuropathy at the axilla. B. Neuralgic amyotrophy. C. C8 radiculopathy. D. Post-median sternotomy lesion. E. Thoracic outlet syndrome.
Answer: D Post-median sternotomy lesions characteristically affect the C8 ventral rami proximally. The findings are most consistent with the sternal retraction producing an occult fracture of the proximal portion of the first rib. This disorder affects bothmen and women and usually is unilateral. It has higher incidence on the side from where the internal mammary artery is used for grafting.
500
An 11-year-old baseball player presents to your clinic complaining of elbow pain. X-rays of the affected side reveal an 8-mm separation of the medial epicondyle. What should be the next step in management? (a) Relative rest for at least 6 weeks (b) Long arm cast for at least 4 weeks (c) Refer to pediatric orthopedic surgeon (d) Physical therapy for strengthening
Answer: C "Little league elbow," seen in throwing athletes with immature skeletons, is a conglomeration of different diagnostic entities caused by valgus and extension-overload. Medial epicondylar avulsion can frequently occur. Separation from 3--5mm can be managed nonsurgically. However, separations greater 5mm usually require surgery.
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