Kyle J. MacGillis, MD; Alfonso Mejia, MD; Maria Z. Siemionow, MD, Hand compression neuropathy: PhD, DSc Department of Orthopaedic Surgery, An assessment guide University of Illinois at Chicago When a patient presents with pain or paresthesias of the [email protected] hand and fingers, knowing what to ask, what to look for, The authors reported no potential conflict of interest and which tests to consider is essential. relevant to this article. europathic hand complaints—for which patients typ- PRACTICE ically seek medical attention when the pain or pares- RECOMMENDATIONS thesia starts to interfere with their daily routine—are ❯ Use provocative testing to N common and diverse. The ability to assess and accurately diag- confirm a suspected diagnosis nose upper extremity compression neuropathies is critical for in a patient who presents with peripheral entrapment physicians in primary care. mononeuropathy. B Assessment starts, of course, with a thorough history of the present illness and past medical history, which helps de- ❯ Consider electrodiagnostic fine a broad differential diagnosis and identify comorbidities. testing for help in diagnosing a challenging presentation, Physical examination, including judicious use of provocative ruling out a competing testing, allows you to objectively identify the pathologic deficit, diagnosis, or clarifying an evaluate function and coordination of multiple organ systems, atypical clinical picture or and detect nerve dysfunction. The results determine whether vague subjective history. A additional tools, such as electrodiagnostic testing, are needed. ❯ Evaluate any patient We’ve created this guide, detailed in the text, tables, and who presents with non- figures that follow, to help you hone your ability to accurately anatomic nerve distribution diagnose patients who present with compression neuropa- of symptoms—eg, burning, thies of the hand. numbness, and tingling of the entire hand—for a metabolic, rather than an The medical history: entrapment, neuropathy. B Knowing what to ask To clearly define a patient’s symptoms and disability, start with Strength of recommendation (SOR) a thorough history of the presenting complaint. A Good-quality patient-oriented evidence ❚ Inquire about symptom onset and chronicity. Did the B Inconsistent or limited-quality pain or paresthesia begin after an injury? Are the symptoms patient-oriented evidence associated with repetitive use of the extremity? Do they occur C Consensus, usual practice, opinion, disease-oriented at night? evidence, case series ❚ Pinpoint the location or distribution of pain or par- esthesia. It is paramount to identify the affected nerve.1,2 Ask patients to complete a hand or upper extremity profile documenting location and/or type of numbness, tingling, or decreased sensation. A diagram of the peripheral nerves re- sponsible for sensory innervation of the hand (FIGURE 1) is an effective way to screen individuals at high risk of carpal tunnel 462 THE JOURNAL OF FAMILY PRACTICE | JULY 2016 | VOL 65, NO 7 syndrome (CTS) or ulnar tunnel syndrome FIGURE 1 (UTS).1,2 Peripheral nerves responsible A patient report such as, “My whole hand is numb,” calls for a follow-up question for sensory innervation of the hand to determine whether the little finger is af- fected,3 which would indicate that the ulnar nerve, rather than just the median nerve, is involved. And if a patient reports feeling as if he or she is wearing gloves or mittens, it is es- sential to consider the possibility of a system- ic neuropathy rather than a single peripheral neuropathy.3 ❚ Gather basic patient information. In- quire about hand dominance, occupation, and baseline function, any or all of which may be critical in the assessment and initia- median tion of treatment.4,5 radial ulnar IMAGE COURTESY OF: KYLE J. MACGILLIS, MD IMAGE COURTESY This diagram of the nerves of the hand can help you pinpoint the source Review systemic conditions of the patient’s pain or paresthesias. and medications A broad range of comorbidities, such as cervical radiculopathy, diabetes, hy- TABLE 1 pothyroidism, and vitamin deficiencies Peripheral neuropathy? 6,7 (TABLE 1), may be responsible for neuro- 6,7 pathic hand complaints, and a thorough re- Some systemic causes view of systemic complaints and past medical Alcohol abuse history is critical. Include a medication his- Amyloidosis tory and a review of prior procedures, such as Cervical radiculopathy post-traumatic surgeries of the hand or upper extremity or nerve decompression surgeries, Diabetes mellitus which may provide additional insight into Environmental toxins disease etiology. Guillain-Barré syndrome HIV Symptoms guide physical exam, Hypothyroidism provocative testing Lyme disease A physical examination, including provoca- Multiple sclerosis tive testing, follows based on reported symp- Scleroderma toms, medical history, and suspected source Vitamin deficiency of nerve compression. HIV, human immunodeficiency virus. Carpal tunnel syndrome CTS is the most common peripheral neurop- athy.8 Patients often report nocturnal pain or can be ascertained during the history of pres- paresthesia in the distal median nerve distri- ent illness. The other 4, detailed below, will be bution, comprising the palmar surface of the found during the physical exam.9 thumb, index, middle, and radial half of the ❚ Thenar weakness or atrophy.9 Be- ring finger. gin your evaluation by inspecting the thenar Researchers have identified 6 standard- musculature for atrophic changes. Motor ized clinical criteria for the diagnosis of CTS. exam of intrinsic musculature innervated Two criteria—numbness mostly in median by the recurrent motor branch of the me- nerve territory and nocturnal numbness— dian nerve includes assessment of thumb JFPONLINE.COM VOL 65, NO 7 | JULY 2016 | THE JOURNAL OF FAMILY PRACTICE 463 TABLE 2 Static 2-point discrimination for hand and wrist14,15 Distance in mm Location Normal Diminished Absent Distal to DIPJ 3-5 6-10 10+ Between DIPJ and PIPJ 3-6 7-10 10+ Central palm 6-9 10-20 20+ Base of palm and wrist 7-10 11-20 20+ DIPJ, distal interphalangeal joint; PIPJ, proximal interphalangeal joint. abduction strength (assessed by applying clip.13 The smallest distance at which the resistance to the metacarpophalangeal joint patient can detect 2 distinct stimuli is then [MCPJ] base towards the palm in the posi- recorded. tion of maximal abduction) and opposition Researchers have reported an average of strength (assessed by applying force to the 3 to 5 mm for 2-point discrimination at the Consider the MCPJ from the ulnar aspect).10 fingertip and a normal 2-point discrimination possibility ❚ Positive Phalen’s test.9 Provocative of 6 to 9 mm in the volar surface of the hand of a systemic testing for CTS includes Phalen’s test (sensi- (TABLE 2).14,15 neuropathy tivity 43%-86%, specificity 48%-67%),11 which The scratch collapse test (sensitivity 64%, in patients who is an attempt to reproduce the numbness or specificity 99%) is a supplemental exam that report that they tingling in the median nerve territory within uses a different outcome measure to diagnose feel as though 60 seconds of full wrist flexion. Ask the pa- CTS.16 It involves lightly scratching the skin they are wearing tient to hold his or her forearms vertically over the compressed carpal tunnel while the gloves. with elbows resting on the table (allowing patient performs sustained resisted bilateral gravity to flex the wrists),12 and to tell you if shoulder external rotation in an adducted po- numbness or tingling occurs. sition. A momentary loss of muscle resistance ❚ Positive Tinel’s sign.9 Tinel’s sign (sen- to external rotation indicates a positive test. sitivity 45%-75%, specificity 48%-67%)11 is performed by lightly tapping the median Pronator syndrome nerve from the proximal to distal end over Pronator syndrome (PS) is a proximal median the carpal tunnel. The test is positive if par- neuropathy that may present in isolation or in esthesia results. Provocative testing may also combination with CTS as a double crush syn- include Durkan’s test, also known as the car- drome. Clinical symptoms include features of pal compression test. Durkan’s test (sensitiv- CTS and sensory paresthesias in the palm and ity 49%-89%, specificity 54%-96%)11 involves distal forearm in the distribution of the palmar placing your thumb directly over the carpal cutaneous branch of the median nerve. PS is tunnel and holding light compression for commonly associated with volar proximal 60 seconds, or until paresthesia is reported. forearm pain exacerbated by repetitive activi- ❚ Positive 2-point discrimination test.9 ties involving pronation and supination. To assess CTS disease severity, use 2-point PS is not easy to assess. Palpatory exami- discrimination to evaluate the patient’s sen- nation of a large supracondylar process at the sation qualitatively and quantitatively. Two- distal humerus proximal to the medial epicon- point discrimination can only be tested, dyle on its anteromedial aspect can be difficult, however, if light touch sensation is intact. especially if the patient is overweight. And mo- It is typically performed by lightly applying tor weakness is not a prominent feature. What’s 2 caliper points at fixed distances sufficient more, power assessment of the pronator teres, to blanch the skin, but some clinicians have flexor carpi radialis, and flexor digitorum su- used other tools, such as a modified paper- perficialis may exacerbate symptoms. CONTINUED 464 THE JOURNAL OF FAMILY