Role of Electrodiagnosis in Ulnar Nerve Entrapments: Difference between revisions
Nehal Shah (talk | contribs) (Added clinical presentation of nerve entrapment) |
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===== Clinical Presentation of Ulnar Nerve Entrapments ===== | ===== Clinical Presentation of Ulnar Nerve Entrapments ===== | ||
Patients usually present with paresthesia and sensory affection in the ring and little finger, hypothenar eminence, dorsal aspect of ulnar sensory supply of hand and ill-defined pain in the region of medial aspect of elbow. With advancing compression, intrinsic muscle weakness causing weak grip, decreased pinch strength, fatigue, clumsiness of the hand, and difficulty with fine motor tasks such as opening bottles or buttoning will be seen. More chronic conditions may lead to marked wasting of the small muscles of the hand and forearm muscles supplied by Ulnar nerve<ref name=":1" /> | Patients usually present with paresthesia and sensory affection in the ring and little finger, hypothenar eminence, dorsal aspect of ulnar sensory supply of hand and ill-defined pain in the region of medial aspect of elbow. With advancing compression, intrinsic muscle weakness causing weak grip, decreased pinch strength, fatigue, clumsiness of the hand, and difficulty with fine motor tasks such as opening bottles or buttoning will be seen. More chronic conditions may lead to marked wasting of the small muscles of the hand and forearm muscles supplied by Ulnar nerve<ref name=":1" />Depending upon the site of compression, clinical presentation may vary. At elbow lesions, patient may present with sensory affection over dorsal hand and hypothenar region whereas this will be spared if the lesion is at wrist. Elbow lesions may present with weakness of FCU and FDP which will be spared in wrist lesions. | ||
Looking at the fascicular arrangement of nerve fiber's, it is seen that FCU and FDP are relatively spared as their nerve fibres occupy deeper intraneural location where as the first dorsal interossei show preferential involvement. Due to the deeper location of intraneural fibres, there is relative sparing of Dorsal Ulnar Cutaneous nerve as well<ref>Kern RZ. The electrodiagnosis of ulnar nerve entrapment at the elbow. Canadian journal of neurological sciences. 2003 Nov;30(4):314-9.</ref> | |||
Revision as of 11:02, 26 November 2023
Original Editor - Nehal Shah
Top Contributor
Introduction[edit | edit source]
Anatomy of Ulnar Nerve[edit | edit source]
Ulnar nerve is the continuation of Medial Cord of Brachial Plexus (C8-T1). It passes in the arm medial to brachial artery . It then enters cubital tunnel and enters the forearm. It supplies Flexor Carpi Ulnaris (FCU) and Flexor Digitorum Profundus (FDP) for ring and little finger. It enters the wrist from Guyon's canal where it divides into Deep Motor branch which supplies Abductor Digiti Minimi, third and fourth Lumbrical, Interossei, Deep head of Flexor Pollicis Brevis and Adductor Pollicis and a Superficial Sensory branch which gives sensory innervation to ulnar border of the ring finger and little finger [1]. Two sensory nerves arise from the Ulnar nerve in the forearm - Dorsal Ulnar Cutaneous Nerve which provides sensory innervation to the dorsal aspect the medial one and a half fingers and the associated dorsal hand area and a Palmar cutaneous nerve that provides innervation to the medial half of the hand.
Entrapment of Ulnar Nerve[edit | edit source]
Ulnar nerve entrapments are the second most common entrapment in Upper extremity after Median Nerve entrapment at Carpal Tunnel. Common causes include pregnancy, diabetes, occupations including repetitive elbow and wrist movements, acute trauma, iatrogenic injuries, cycling, and other recreational sports [2].Ulnar Nerve entrapments mostly occurs at two sites
- Ulnar Nerve Entrapment in Cubital Tunnel - This is an entrapment of the nerve in the cubital tunnel and occurs mainly due to compression by Osborne's ligament[1], larger coronoid process in men with lesser subcutaneous fats around it compared to women makes them more vulnerable to entrapment compared to women[3],and trauma.
- Ulnar Nerve Entrapment in Guyon's Canal - Compression of Ulnar nerve at wrist occurs in Guyon's Canal mainly due to occupations involving repetitive wrist movements and cycling activities apart from trauma. Guyon's canal is divided into three zones. Zone 1 lies proximal to the bifurcation of the nerve into Deep Palmar branch and Superficial Sensory branch. Zone 2 lies distal to zone 1 and surrounds motor branch. Zone 3 is distal to zone 2 and it surrounds only the sensory branch[1]
Clinical Presentation of Ulnar Nerve Entrapments[edit | edit source]
Patients usually present with paresthesia and sensory affection in the ring and little finger, hypothenar eminence, dorsal aspect of ulnar sensory supply of hand and ill-defined pain in the region of medial aspect of elbow. With advancing compression, intrinsic muscle weakness causing weak grip, decreased pinch strength, fatigue, clumsiness of the hand, and difficulty with fine motor tasks such as opening bottles or buttoning will be seen. More chronic conditions may lead to marked wasting of the small muscles of the hand and forearm muscles supplied by Ulnar nerve[2]Depending upon the site of compression, clinical presentation may vary. At elbow lesions, patient may present with sensory affection over dorsal hand and hypothenar region whereas this will be spared if the lesion is at wrist. Elbow lesions may present with weakness of FCU and FDP which will be spared in wrist lesions.
Looking at the fascicular arrangement of nerve fiber's, it is seen that FCU and FDP are relatively spared as their nerve fibres occupy deeper intraneural location where as the first dorsal interossei show preferential involvement. Due to the deeper location of intraneural fibres, there is relative sparing of Dorsal Ulnar Cutaneous nerve as well[4]
Sub Heading 2[edit | edit source]
Sub Heading 3[edit | edit source]
Resources[edit | edit source]
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References[edit | edit source]
- ↑ 1.0 1.1 1.2 Davis DD, Kane SM. Ulnar Nerve Entrapment.
- ↑ 2.0 2.1 Vij N, Traube B, Bisht R, Singleton I, Cornett EM, Kaye AD, Imani F, Erdi AM, Varrassi G, Viswanath O, Urits I. An update on treatment modalities for ulnar nerve entrapment: a literature review. Anesthesiology and Pain Medicine. 2020 Dec;10(6).
- ↑ Contreras MG, Warner MA, Charboneau WJ, Cahill DR. Anatomy of the ulnar nerve at the elbow: potential relationship of acute ulnar neuropathy to gender differences. Clinical Anatomy: The Official Journal of the American Association of Clinical Anatomists and the British Association of Clinical Anatomists. 1998;11(6):372-8.
- ↑ Kern RZ. The electrodiagnosis of ulnar nerve entrapment at the elbow. Canadian journal of neurological sciences. 2003 Nov;30(4):314-9.
