CASE 29 Occupational Disorder - Virginia Tech



Objectives:

i. Describe the symptoms, signs, and management of DeQuervain’s tenosynovitis

ii. Describe the symptoms, signs, and management of Carpal Tunnel Syndrome

iii. Describe the symptoms, signs, and management of Diabetic Peripheral Neuropathy

iv. Describe the risk Factors for Carpal Tunnel Syndrome

v. Describe preventive measures that might be taken for Dequervain’s tenosynovitis, Carpal Tunnel Syndrome, and Diabetic Peripherral Neuropathy

USC Case # 9: Occupational Disorder

A 45 year old female Administrative Assistant at Virginia Tech presents to your office with progressively worsening wrist and hand pain and “numbness” over the past 4-6 weeks. She works at a computer about 8 hours a day. Up until 6 weeks ago, she was on the computer only 4-5 hours per day. The wrist pain worsened as the day went on, but she could continue her work at first. Now the pain does not allow her to type more than 10-20 minutes at a time without resting and “stretching “ her wrists. The pain progressed to “numbness and tingling” in her hands about 3 weeks ago and now this symptom wakes her from her sleep. She has taken Aleve with some pain relief.

Past Medical History

She had a similar problem, but not as severe, when she was pregnant the last time. She is gravida 3 para 3. She is hypertensive and “borderline Diabetic”. She has a very sedentary lifestyle.

Examination:

Temp. 98.8 P84 R 16 Height: 5’ 4” Weight: 245lb

Her forearms appear normal size and the skin appears to be the same color, temperature and texture as the rest of her upper extremities. There is diffuse mild palpable tenderness in the forearms which is bilaterally equal. Active wrist ROM causes increased pain, especially full palmar flexion. The tingling she describes is from the midwrist to the tips of the thumb, the index, middle, and radial aspect of the ring fingers. She has a positive Tinel’s sign and Phalen’s sign bilaterally. Her grip strength seems weak bilaterally as well.

Questions?

1. What caused this problem to develop?

Repetitive wrist movements causing swelling and entrapment of median nerve as it passes through the Carpal tunnel in the wrist

2. Did this patient have any predisposing factors?

a. Obesity, work involving repetitive wrist motion, borderline diabetes

3. Could this have been prevented? How?

a. Weight loss, Wrist splints, appropriate support of wrists while working on computer

4. What medications might help?

a. NSAID’s, Corticosteroid injection

5. What treatments will help relieve the pain and tingling?

a. Wrist splints

b. Carpal Tunnel Nerve Glide exercises

c. NSAID’s

d. Corticosteroid injection

e. Surgical release

6. When is surgery indicated for this condition?

a. Symptoms are not relieved or return after trying above therapies

Answer these questions prior to advancing to the next page.

Differential:

1. deQuervain’s Tenosynovitis of the wrists

2. Carpal Tunnel Syndrome

3. Diabetic Peripheral Neuropathy

1. de Quervain’s tenosynovitis is swelling or stenosis of the sheath that surrounds the adductor pollicis longus and extensor pollicis brevis tendons on the thumb side at the wrist. The inflammation thickens the tendon sheath (tenosynovium) and constricts the tendon as it glides in the sheath. This can cause pain, swelling, and a triggering phenomenon, with the tendon seeming to lock or stick as the patient moves the thumb. It is more common in middle-aged women and is often precipitated by repetitive use of the thumb.

Clinical Symptoms: Patients report pain and swelling over the radial styloid that is aggravated by attempts to move the thumb or make a fist. They also may notice creaking as the tendon moves.

Physical Examination: Exam reveals swelling and tenderness over the tendons in the region of the distal radius. Crepitus may be palpable as the patient flexes and extends the thumb. Full flexion of the thumb into the palm, followed by ulnar deviation of the wrist (Finkelstein test), will produce pain and is diagnostic for this condition.

Diagnostic tests: Even though this is largely a clinical diagnosis, posteroanterior and lateral radiographs of the wrist should be considered to rule out any bony abnormality, such as a deformed radial styloid process that might be a precipitating cause if there is a history of trauma. Calcification associated with tendinitis occasionally can be seen on radiographs.

Adverse Outcomes of the Disease: Chronic pain, loss of strength and loss of thumb motion can occur; tendon rupture is possible, but rare.

Treatment: Initial treatment should consist of a thumb spica splint that immobilizes both the wrist and the thumb. A 2-week course of NSAIDS is helpful for pain relief and anti-inflammatory activity. If this fails, the tendon sheath can be injected with a corticosteroid. There should be no more than 3 injections. Surgery should be considered if the injections fail.

Adverse Outcomes of Treatment: NSAIDS can cause gastric, renal, or hepatic complications. The patient can experience some discomfort from wearing the splint and might stop using it. Corticosteroids can sometimes cause subcutaneous atrophy and unsightly loss of skin pigmentation. Infection after injection also is a risk, but can largely be avoided by careful use of aseptic technique. Injury to the radial sensory nerve or incomplete release is possible with operative treatment.

2. Carpal tunnel syndrome is the most common compression neuropathy in the upper extremity. It most commonly affects middle-aged or pregnant women. Any condition that reduces the size or space of the carpal tunnel can cause compression of the median nerve, resulting in paresthesias, pain, and sometimes paralysis. Common precipitating conditions include tenosynovitis of the adjacent flexor tendons (repetitive overuse trauma or rheumatoid arthritis), tumors, and medical conditions such as pregnancy or thyroid dysfunction that increase edema, or associated neuritis from diabetes.

Clinical Symptoms: Patients typically report a vague aching that radiates into the thenar area. Aching may also be perceived in the proximal forearm, and occasionally the pain can extend to the shoulder. The pain is typically accompanied by paresthesias and numbness in the median distribution (thumb, index, middle, and radial half of the ring fingers, or some combination thereof).

Patients report that they frequently drop objects, or that they cannot open jars or twist off lids. Pain or numbness sometimes is made worse by activities that require repetitive motion of the hand, repetitive activities, or stationary tasks done with the wrist held flexed or extended for long periods, such as when driving or reading. Patients often awaken at night with pain or numbness and typically report the need to rub or shake the hand to” get the circulation back”. When the compression is severe and long-standing, persistent numbness and thenar atrophy can occur.

Physical Examination: Inspect the hand for thenar atrophy. Check sensation of the median and ulnar nerves. Testing thumb opposition against resistance may reveal weakness of the thenar muscles.

The Phalen test is the most useful clinical test and is performed by placing the wrists in flexion. Aching and/or numbness in the distribution of the median nerve within 60 seconds (often within 15 seconds or less) is a positive test for carpal tunnel syndrome. Tapping over the median nerve at the wrist may produce tingling in some or all of the digits in the median nerve distribution ( a positive Tinel’s sign). Thumb pressure over the median nerve at the wrist for up to 30 seconds may elicit pain or paresthesias in the median nerve distribution.

Patients with CTS may be unable to distinguish the two point of a caliper as separate points when they are closer than 5mm together.

Diagnostic Tests: Xrays of the wrist should be obtained if the patient has limited wrist motion or history of trauma. The most helpful diagnostic test is a median nerve conduction velocity study, however, 5-10% of patients with CTS have normal results. If positive, the patient is usually a candidate for surgery.

Adverse Outcomes of the Disease: Permanent loss of sensation is possible, as are thenar atrophy and weakness of opposition.

Treatment: For mild cases, splinting the wrist and a short-term course of NSAIDS or oral corticosteroids can be tried. The splint should be worn at night (at a minimum) and can be worn during the day if doing so does not interfere with the patient’s work or daily activities. OMT is often very useful. If these measures fail, consider injecting a corticosteroid into the carpal canal. Care must be taken to avoid direct injection into the median nerve.

Work-related CTS may be improved with ergonomic modifications, such as keyboard or forearm supports, adjusting the height of computer keyboards, and avoiding holding the wrist in a flexed position. Patients with acute CTS may have wrist pain rather than the more typical signs of numbness or thenar weakness. These patients usually respond well to steroid injections.

CTS of pregnancy usually resolves with the end of the pregnancy: therefore, treatment should consist of splinting and, in severe cases, steroid injection.

Surgery is necessary for patients who have atrophy or weakness of the thenar muscles or decreased sensation, and for those who have intolerable symptoms despite conservative treatment.

ESSENTIALS OF MUSCULOSKELETAL CARE, Walter B. Greene, MD, 2nd Edition, 2001.

3. Diabetic peripheral neuropathies may be classified as either mononeuropathies or symmetric polyneuropathies, but neuropathy is frequent and mixed syndromes can occur.

Pathogenesis: The clinical features of symmetric polyneuropathy (the most common type) which often selectively involve particular fiber types, favor a metabolic basis. Elevated levels of neurotoxic ketones have been sought but not found.

Confounding a metabolic explanation is the inconsistent relationship of severity of neuropathy to control of blood glucose. There are many instances of “well controlled” patients who develop severe sensorimotor neuropathy and others with “poor control” who have no evidence of neuropathy. The balance of recent evidence favors the notion that hyperglycemia is an important determinant of diabetic neuropathy and improved glycemic control is beneficial for nerve function.

Clinical Features and Treatment: Distal primary sensory neuropathy is the commonest type of diabetic peripheral neuropathy, estimated to be present in about 40% of individuals with diabetes of 25 years’ duration. It is present in less than 10% of patients at the time of diagnosis and is uncommon in children.

Neuropathy may be asymptomatic, with abnormal signs first detectable on routine exam or there may be a variety of symptoms. The “large fiber” pattern with paresthesias in legs, absent ankle jerks, and impaired senses of light touch, vibration, and position of the lower limbs can be associated with slight distal weakness and the hands may become involved. It is extremely rare for hands alone to exhibit neuropathy without involvement of the feet.

There is no specific treatment. Simple analgesics rarely help and a trial of phenytoin, carbamazepine, phenothiazine, or tricyclic antidepressants is advocated. Neurontin is currently prescribed most often.

The most likely cause of this patient’s symptoms is Carpal Tunnel Syndrome.

How can this be treated conservatively?

If left untreated, what serious outcomes can occur?

What are the indications for surgery?

The answers can be found in the above material.

Readings: Rakel’s Textbook of Family Medicine pp 659 - 661

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