A 56-years old female presents with nocturnal pain in the right thumb, index and middle fingers for the past 3 months. All of the provocative tests can be performed except –
**Question:** A 56-years old female presents with nocturnal pain in the right thumb, index and middle fingers for the past 3 months. All of the provocative tests can be performed except -
A. Tinel's sign
B. Phalen's test
C. Finkelstein's test
D. Dinner plate test
**Correct Answer:** **D. Dinner Plate Test**
**Core Concept:** Provocative tests are diagnostic maneuvers used to provoke symptoms in patients with suspected peripheral nerve disorders. These tests help in localizing the nerve involvement and differentiate it from other causes of pain.
**Why the Correct Answer is Right:**
Dinner Plate test, also known as the 'Finkelstein's Test' or 'Finkelstein's Sign', is a test for the ulnar nerve. It involves flexing the thumb at the base of the thumb and applying pressure to the ulnar styloid process, which is located on the ulnar side of the wrist near the base of the little finger. The test is performed to assess the integrity of the ulnar nerve, particularly in cases of ulnar nerve entrapment or compression syndromes like ulnar nerve entrapment at the elbow, carpal tunnel syndrome, or cubital tunnel syndrome.
**Why Each Wrong Option is Incorrect:**
A. Tinel's sign: This test is performed by tapping or lightly striking the median nerve distribution over the carpal tunnel. It is useful in diagnosing carpal tunnel syndrome and is not specific for ulnar nerve disorders.
B. Phalen's test: This test is performed by flexing the wrist joint and assessing the presence of pain or tingling in the distribution of the median nerve. Phalen's test is not specific for ulnar nerve disorders and is mainly used for diagnosing carpal tunnel syndrome.
C. Finkelstein's test (Option D): This test is performed as mentioned above and is specific for assessing the ulnar nerve, particularly in cases of ulnar nerve entrapment or compression syndromes.
**Clinical Pearl:**
The dinner plate test is a valuable clinical tool in diagnosing ulnar nerve entrapment or compression syndromes, such as cubital tunnel syndrome, Guyon's canal syndrome, or ulnar nerve compression at the wrist. It is specific for the ulnar nerve, whereas the other tests mentioned are specific to median nerve disorders. Hence, performing the dinner plate test is crucial in distinguishing between ulnar nerve and median nerve disorders.