In this era of telemedicine , the perception and recognition of diagnostic clinical signs has become a coveted skill ; one is reminded of the great clinicians of the past , many of whom made an “ instant diagnosis ” just by observing the patient for a few minutes . The great author , Arthur Conan Doyle created the immortal character of the master detective , Sherlock Holmes , fashioned after one of his medical teachers , Dr . Joseph Bell , who used his astute observation skills to make quick deductions .
FEATURE
“ HAND OF BLESSING ” GOES FROM BOON TO BANE FOR
THE PHYSICIAN-TRAINEE
Next to facial expression and speech , observation of hands provides several important clues to many neurological conditions . These may be findings at rest ( postures , muscle atrophy , abnormal movements ) or during specific actions that the patient may be requested to do ( making a fist , rapid alternating movements , finger to nose test , showing the “ UofL sign ” and many more ) during a telemedicine visit . There are several “ hand signs ” that often provide insight into an underlying neurological disorder , especially those affecting peripheral nerves ; recognition of these signs is particularly important for neurologists , neurosurgeons as well as hand and orthopedic surgeons . Many of these signs have eponyms , reminding us of the master physicians who excelled in the art of medical semiology .
A question on the well-known clinical sign , “ Hand of Benediction ” ( Blessing hand , Preacher ’ s hand ) occasionally appears in the United States Medical Licensing Examination and American Board of Medical Specialties examinations . In my student days , from among the multiple answer choices , I could easily pick proximal median neuropathy , and feel 100 % confident that I chose the right response . The reason for the specific hand posture is the inability to flex the radial three digits due to weakness of digital flexor muscles , innervated by the median nerve in the forearm ; the intact long flexors of digits four and five , innervated by the ulnar nerve enable flexed position of the small and ring fingers giving rise to the posture of the “ Hand of Benediction .” There has been some controversy in that a few anatomy sources considered this to be a sign of ulnar rather than median neuropathy with the explanation that the underlying problem is loss of ulnar nerve-innervated lumbricals that extend the interphalangeal joints of digits four and five . The controversy received much more attention with the publication of an insightful paper by Bennett Futterman titled Analysis of the Papal Benedict sign : The Ulnar Neuropathy of St . Peter in 2015 . 1 By “ in depth analysis of functional anatomy of the hand , and the cultural and religious practices of the early centuries of the Common Era and
AUTHOR Vasudeva Iyer , MD
church art ,” he concluded that the hand posture resulted from ulnar neuropathy . He reasoned that when the Pope gave a blessing , it is likely that his intention was to keep the hand open with extended fingers ( and unlikely that he would keep a closed fist to bless ). On the basis of this premise , Futterman reasoned that Pope Peter may have had ulnar neuropathy causing inability to extend digits four and five , leading to the unusual hand posture of benediction , which may have been imitated and carried down centuries as a mark of respect to Pope Peter .
Considering the controversy , it would be great if question setters for the USMLE and ABMS modify the wording of the question : If the “ Hand of Benediction ” occurs while flexing of the fingers to make a fist , the cause is proximal median neuropathy . On the other hand , if the “ Hand of Benediction ” occurs while extending the fingers , the cause is ulnar neuropathy ( Figures 1 & 2 ). Apart from board questions , current practitioners using telemedicine can also make use of these clues by asking the patient to flex and later extend all the fingers . One would expect that simple commands like flexing and extending fingers should be easy to use during the telehealth visit ; however , in this era , when intimidation and bullying have become fashionable , I wonder whether it makes more sense to use lay commands such as show a “ punching ” hand ( flexion of fingers ) and a “ slapping ” hand ( extension of fingers ).
Reference :
HAND OF BENEDICTION
A : MAKE A FIST
Median Neuropathy
1
Futterman B . Analysis of the Papal Benedict Sign : The Ulnar Neuropathy of St . Peter . Clin . Anat . 28:696-701 , 2015
B : STRAIGHTEN ALL FINGERS
Ulnar Neuropathy
Dr . Iyer practices at the Neurodiagnostic Center of Louisville and is a retired professor of neurology at the University of Louisville School of Medicine .
DECEMBER 2020 23