Carpal Tunnel Syndrome: Diagnosis and Treatment

00:01 So, let's talk a little bit about mononeuropathies.

00:03 And I want you to remember three common mononeuropathies.

00:07 These are conditions that affect a single nerve.

00:10 Often at a compression site.

00:12 We think about median mononeuropathy, which is carpal tunnel syndrome.

00:16 Ulnar mononeuropathy which can occur at the elbow and is a sensitive compression site at the elbow, and fibular mononeuropathy in the leg.

00:25 Let's talk a little bit about carpal tunnel syndrome and use that to understand other focal compressive mononeuropathies.

00:32 In terms of signs and symptoms, patients typically present with pain, paraesthesia, weakness, and if not improved, or intervened upon ultimately atrophy.

00:41 as a result of compression of the single nerve.

00:44 The median nerve is susceptible to compression in the carpal tunnel, and you can see a cross section of the hand and wrist here.

00:52 The median nerve is sensitive to compression as a result of a number of things.

00:56 The first is all of the muscles that are beneath the median nerve and you can see that here.

01:00 And a tough fascial layer that extends over the wrist.

01:04 With repetitive injury or repetitive use, there's swelling of the muscles, there can result in swelling of the nerve.

01:11 And that window, that area that the nerve travels through is at risk for compression.

01:17 This results in focal dysfunction and problem in that nerve motor symptoms, sensory symptoms and ultimately atrophy.

01:25 There are a number of diagnostic tests that we can use to evaluate patients who present with numbness and weakness in the hands and evaluate for carpal tunnel syndrome.

01:34 And what we're doing is putting that median nerve in a potentially compressed situation to see whether that will reproduce the patient's symptoms of numbness and tingling extending down the median nerve distribution.

01:47 Here you can see Phalen sign, a demonstrated there and a positive Phalen sign will be reproduction of numbness and tingling, and paresthesias in a median nerve distribution.

01:57 And then Tinel's sign which is tapping over the median nerve as it travels through the carpal tunnel.

02:03 And again, a positive sign is reproducing the patient's symptoms numbness and tingling in a median nerve distribution.

02:11 To evaluate these patients, we can consider imaging although neuromuscular ultrasound would be probably favorable imaging as opposed to MRI or CT.

02:18 And nerve conduction study is the workhorse and gold standard of confirmatory testing when there are unclear clinical features.

02:27 Ultimately, the diagnosis of carpal tunnel can be made by clinical diagnosis.

02:34 Let's talk a little bit about median and ulnar neuropathies.

02:37 Those are the two nerves that travel out into the distal arm and are susceptible to compression.

02:43 Ulnar neuropathy may present with an ulnar claw.

02:46 The nerve involved is the ulnar nerve and it can be at the wrist.

02:50 We can also see ulnar nerve compression more commonly at the elbow.

02:53 The typical presentation is this appears in long standing cases of nerve damage.

03:00 The digits that are affected are the fourth and fifth digits.

03:03 We see muscles that can be paralyzed, and that's isolated to the medial to lumbricals.

03:08 And it tends to be that movements that are involved is unopposed extension of the MCP joints, and an unopposed flexion of the interphalangeal joints.

03:18 This is different than what we see with median nerve pathology, which is the hand of benediction.

03:23 Here lesions of the median nerve can occur at the elbow or wrist.

03:27 This appears when the patient attempts to make a fist.

03:30 The patient attempts to make a fist, and the fourth and fifth digit work but we don't see flexion and function of the first three digits.

03:38 This affects the lateral half of the flexor digitorum profundus and the lateral to lumbricals.

03:44 And there's inability to perform flexion at the MCP and IP joints of the three fingers.

03:50 And here's two schematics of the claw hand and hand of an addiction.

03:54 Seeing the claw hand should point towards the concern of ulnar nerve pathology, the inability to flex the fourth and fifth digit.

04:02 Whereas hand had been addiction should point towards problems with the median nerve.

04:05 And again, that's inability to flex the first three digits.

04:11 Let's talk a little bit more about how we treat patients with carpal tunnel syndrome.

04:14 Well, there are a number of steps we can go through to evaluate and manage these patients.

04:18 One of the first questions we have is, is the patient pregnant? Carpal Tunnel Syndrome is common more common in pregnancy.

04:24 It's one of the most common focal compressive neuropathies during pregnancy as a result of fluid shifts.

04:30 If the patient is pregnant, we wouldn't consider surgery and conservative measures would be pursued.

04:35 If the patient is not pregnant, we want to understand the severity of symptoms and we'll use our clinical exam and potentially electrodiagnostic testing.

04:42 If symptoms are mild, nonsurgical measures such as splinting, or corticosteroid injection can be considered.

04:48 For patients with moderate to severe symptoms, many of these patients would be referred for nerve conduction study and EMG (electrodiagnostic testing).

04:58 When electrodiagnostic testing is done, if there's evidence of axonal loss that indicates that already that nerve is de-innervated and there may be limited benefit with surgical decompression, and non-surgical measures, splinting corticosteroid injections are pursued.

05:13 But for patients without those end organ damage, axonal loss and denervation, surgical decompression to release the median nerve may be considered.