Arch Orthop Trauma Surg (2015) 135:891–893 DOI 10.1007/s00402-015-2216-8
HANDSURGERY
A rare case of a punched nerve syndrome of the deep motor branch of the ulnar nerve Leonhard Gruber1 • Hannes Gruber1 • Thomas Bauer2 • Alexander Loizides1
Received: 24 October 2014 / Published online: 7 April 2015 Ó Springer-Verlag Berlin Heidelberg 2015
Abstract Introduction Peripheral compression neuropathy of the ulnar nerve is a frequent condition, most likely encountered at the ulnar sulcus or the Guyon’s canal. High-resolution ultrasound (HRUS) can often identify the site of injury. Primarily idiopathic, compression neuropathy can stem from a punched nerve syndrome, in which direct contact between an arterial branch and the nerve leads to compression. Materials and methods A 42-year-old male patient was examined by means of HRUS using a 17-5 MHz linear transducer on a Philips iU22Ò (Philips, Bothell, Washington, USA). Results After reporting a punched nerve syndrome of the deep motor branch of the ulnar nerve distal to the Guyon’s canal, the patient underwent surgery and showed electrophysiological and clinical improvement 6 months after decompression. Conclusion HRUS is a viable method to demonstrate a punched nerve syndrome. In conjunction with clinical presentation, even unlikely sites of compression such as the deep motor branch of the ulnar nerve can be identified. Keywords Punched nerve syndrome Ulnar nerve Ulnar tunnel syndrome Ultrasonography
& Leonhard Gruber [email protected] 1
Department of Radiology, Medical University Innsbruck, Anichstraße 35, Innsbruck, Austria
2
Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University Innsbruck, Anichstraße 35, Innsbruck, Austria
Introduction Peripheral compression mononeuropathies of the upper extremity are frequently encountered in everyday routine; while many conditions remain idiopathic, a causative mechanism can often be identified via high-resolution ultrasound (HRUS) [1]. Ulnar nerve neuropathy is the second most common peripheral compression neuropathy. The annual incidence rate regardless of location is 25.2 and 18.9 per 100,000 for men and women, respectively [2]. Its most likely site of entrapment is within the ulnar sulcus or the Guyon’s canal [3, 4]. Nonetheless other sites of compression have to be taken into account when examination of those two regions reveals no pathology. As the ulnar nerve gives off several sensory and motor branches along its course proximal and distal to the Guyon’s canal, symptoms depend on the site of injury and a likely site of injury may be established during clinical examination [5]. The deep branch of the ulnar nerve supplies the hypothenar muscles, the first dorsal and palmar interosseous muscles and the adductor pollicis and the deep head of the flexor pollicis brevis. While compression neuropathy of the ulnar nerve often remains idiopathic, other possible causes of damage include anatomical variations such as a prominent hook of the hamate, trauma, mechanical irritation and compression due to benign or malign tumors [6]. Recently authors could demonstrate an ultrasonographic correlate to the so-called ‘punched-nerve-syndrome’ (PNS), a rare condition under which direct vicinity to a vascular structure leads to chronic neural damage due to repeated pulsatile compression [7]. In this article, we present a patient with a ‘punched nerve syndrome’ affecting the deep motor branch of the ulnar nerve.
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Case presentation A 42-year-old male patient was referred to our department for sonographic assessment of the ulnar nerve due to a persisting distal ulnar paresis, despite a decompression surgery at the Guyon’s canal 11 months earlier. The patient described weakness and clumsiness of the right hand, but no numbness or pain. Inspection revealed a significant atrophy of the interosseous muscles, hypothenar and thenar. Electrophysiological findings suggested a distal ulnar nerve lesion affecting motor branches. Ultrasonography of the ulnar nerve was performed on a Philips iU22Ò (Philips, Bothell, Washington, USA) using a 17-5 MHz broadband linear array transducer and a 10-mm stand-off gel pad (SONAR-AID, Geistlich Pharma, Wolhusen, Switzerland). Ultrasonography revealed no neural damage at the upper arm, elbow, lower arm or wrist. Additionally no significant scarring at the site of decompression at the Guyon’s canal was present.
Fig. 1 Three consecutive preoperative axial ultrasound images of the deep branch of the ulnar nerve (white arrowhead) taken distal to the Guyon’s canal: normal appearance proximal to the site of compression with regular fasciculation (a) and hypoechoic thickening of the
Arch Orthop Trauma Surg (2015) 135:891–893
Further investigation of the palmar branches of the ulnar nerve revealed a short hypoechoic increase in diameter of the deep branch of the ulnar nerve. At that level a prominent radial branch of the superficial palmar arc was depicted using color duplex imaging with interposition of the nerve between the artery and the carpal bones. Cineloop imaging was used to demonstrate repetitive pulsatile intravascular flow in direct contact with the nerve (Fig. 1). Due to these findings the patient underwent surgery under general anesthesia. The above findings could be confirmed intraoperatively (Fig. 2), where a release of the compressed motor branch was performed via ligation of the respective crossing arterial branch. Six months after decompression, the patient described an improvement in clinical symptoms. Accordingly EMG demonstrated a reappearance of motor responses of the second dorsal interosseous muscle after stimulation of the ulnar nerve.
nerve immediately proximal to the site of compression (b), which was caused by a crossing branch (empty white arrow) arising from the ulnar artery (asterisk) (c)
Fig. 2 Intraoperative situs showing the deep branch (white arrowhead) of the ulnar nerve (black arrow) and a crossing branch (empty white arrow) of the ulnar artery (asterisk) before (a) and after release (b)
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Arch Orthop Trauma Surg (2015) 135:891–893
893
Discussion
Conclusion
A rarer form among peripheral compression neuropathies, the so-called ‘punched nerve syndrome’, was only recently reliably demonstrated using HRUS in a series of patients. It is thought to arise from repeated pulsatile neural compression by an adjacent vascular structure [7]. The defining characteristics of a PNS are a well-circumscribed hypoechoic enlargement of the neural diameter at the site of a crossing artery. In our patient, who already had undergone decompression surgery of the ulnar nerve at the Guyon’s canal without symptom relief, a pathological neurovascular contact syndrome of the deep ulnar motor branch was revealed by means of HRUS. The patient had displayed persisting dyspraxia and atrophy of the interosseous, hypothenar and thenar muscles. A lack of sensitive deficits and nerve conduction velocity findings in concordance with distal motor neuron damage suggested a site of injury within or distal to the canal of Guyon. Consequently decompression surgery at this site led to improvement of symptoms 6 months after decompression. Thorough history taking and clinical examination is essential in narrowing down possible sites of neural damage in a suspected ulnar tunnel syndrome [5]. An experienced examiner can use HRUS to identify the location and cause of such neural damage through dynamic interaction with the patient.
In this case HRUS could identify the site of compression of the deep ulnar branch in the palm due to a punched nerve syndrome, a rare but noteworthy cause of peripheral compression neuropathies. Conflict of interest
None.
References 1. Kopf H, Loizides A, Mostbeck G, Gruber H (2011) Diagnostic sonography of peripheral nerves: indications, examination techniques and pathological findings. Ultraschall Med 32(3):242–263 2. Latinovic R, Gulliford M, Hughes R (2006) Incidence of common compressive neuropathies in primary care. J Neurol Neurosurg Psychiatry 77(2):263–265 3. Dawson D (1993) Entrapment neuropathies of the upper extremities. N Engl J Med 329(27):2013–2018 4. Beltran J, Rosenberg Z (1994) Diagnosis of compressive and entrapment neuropathies of the upper extremity: value of MR imaging. AJR Am J Roentgenol 163(3):525–531 5. Chen S, Tsai T (2014) Ulnar tunnel syndrome. J Hand Surg Am 39(3):571–579 6. Murata K, Shih J, Tsai T (2003) Causes of ulnar tunnel syndrome: a retrospective study of 31 subjects. J Hand Surg Am 28(4):647–651 7. Loizides A, Peer S, Plaikner M, Djurdjevic T, Gruber H (2012) Punched nerve syndrome: ultrasonographic appearance of functional vascular nerve impairment. Ultraschall Med 33(4):352–356
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HANDSURGERY
A rare case of a punched nerve syndrome of the deep motor branch of the ulnar nerve Leonhard Gruber1 • Hannes Gruber1 • Thomas Bauer2 • Alexander Loizides1
Received: 24 October 2014 / Published online: 7 April 2015 Ó Springer-Verlag Berlin Heidelberg 2015
Abstract Introduction Peripheral compression neuropathy of the ulnar nerve is a frequent condition, most likely encountered at the ulnar sulcus or the Guyon’s canal. High-resolution ultrasound (HRUS) can often identify the site of injury. Primarily idiopathic, compression neuropathy can stem from a punched nerve syndrome, in which direct contact between an arterial branch and the nerve leads to compression. Materials and methods A 42-year-old male patient was examined by means of HRUS using a 17-5 MHz linear transducer on a Philips iU22Ò (Philips, Bothell, Washington, USA). Results After reporting a punched nerve syndrome of the deep motor branch of the ulnar nerve distal to the Guyon’s canal, the patient underwent surgery and showed electrophysiological and clinical improvement 6 months after decompression. Conclusion HRUS is a viable method to demonstrate a punched nerve syndrome. In conjunction with clinical presentation, even unlikely sites of compression such as the deep motor branch of the ulnar nerve can be identified. Keywords Punched nerve syndrome Ulnar nerve Ulnar tunnel syndrome Ultrasonography
& Leonhard Gruber [email protected] 1
Department of Radiology, Medical University Innsbruck, Anichstraße 35, Innsbruck, Austria
2
Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University Innsbruck, Anichstraße 35, Innsbruck, Austria
Introduction Peripheral compression mononeuropathies of the upper extremity are frequently encountered in everyday routine; while many conditions remain idiopathic, a causative mechanism can often be identified via high-resolution ultrasound (HRUS) [1]. Ulnar nerve neuropathy is the second most common peripheral compression neuropathy. The annual incidence rate regardless of location is 25.2 and 18.9 per 100,000 for men and women, respectively [2]. Its most likely site of entrapment is within the ulnar sulcus or the Guyon’s canal [3, 4]. Nonetheless other sites of compression have to be taken into account when examination of those two regions reveals no pathology. As the ulnar nerve gives off several sensory and motor branches along its course proximal and distal to the Guyon’s canal, symptoms depend on the site of injury and a likely site of injury may be established during clinical examination [5]. The deep branch of the ulnar nerve supplies the hypothenar muscles, the first dorsal and palmar interosseous muscles and the adductor pollicis and the deep head of the flexor pollicis brevis. While compression neuropathy of the ulnar nerve often remains idiopathic, other possible causes of damage include anatomical variations such as a prominent hook of the hamate, trauma, mechanical irritation and compression due to benign or malign tumors [6]. Recently authors could demonstrate an ultrasonographic correlate to the so-called ‘punched-nerve-syndrome’ (PNS), a rare condition under which direct vicinity to a vascular structure leads to chronic neural damage due to repeated pulsatile compression [7]. In this article, we present a patient with a ‘punched nerve syndrome’ affecting the deep motor branch of the ulnar nerve.
123
892
Case presentation A 42-year-old male patient was referred to our department for sonographic assessment of the ulnar nerve due to a persisting distal ulnar paresis, despite a decompression surgery at the Guyon’s canal 11 months earlier. The patient described weakness and clumsiness of the right hand, but no numbness or pain. Inspection revealed a significant atrophy of the interosseous muscles, hypothenar and thenar. Electrophysiological findings suggested a distal ulnar nerve lesion affecting motor branches. Ultrasonography of the ulnar nerve was performed on a Philips iU22Ò (Philips, Bothell, Washington, USA) using a 17-5 MHz broadband linear array transducer and a 10-mm stand-off gel pad (SONAR-AID, Geistlich Pharma, Wolhusen, Switzerland). Ultrasonography revealed no neural damage at the upper arm, elbow, lower arm or wrist. Additionally no significant scarring at the site of decompression at the Guyon’s canal was present.
Fig. 1 Three consecutive preoperative axial ultrasound images of the deep branch of the ulnar nerve (white arrowhead) taken distal to the Guyon’s canal: normal appearance proximal to the site of compression with regular fasciculation (a) and hypoechoic thickening of the
Arch Orthop Trauma Surg (2015) 135:891–893
Further investigation of the palmar branches of the ulnar nerve revealed a short hypoechoic increase in diameter of the deep branch of the ulnar nerve. At that level a prominent radial branch of the superficial palmar arc was depicted using color duplex imaging with interposition of the nerve between the artery and the carpal bones. Cineloop imaging was used to demonstrate repetitive pulsatile intravascular flow in direct contact with the nerve (Fig. 1). Due to these findings the patient underwent surgery under general anesthesia. The above findings could be confirmed intraoperatively (Fig. 2), where a release of the compressed motor branch was performed via ligation of the respective crossing arterial branch. Six months after decompression, the patient described an improvement in clinical symptoms. Accordingly EMG demonstrated a reappearance of motor responses of the second dorsal interosseous muscle after stimulation of the ulnar nerve.
nerve immediately proximal to the site of compression (b), which was caused by a crossing branch (empty white arrow) arising from the ulnar artery (asterisk) (c)
Fig. 2 Intraoperative situs showing the deep branch (white arrowhead) of the ulnar nerve (black arrow) and a crossing branch (empty white arrow) of the ulnar artery (asterisk) before (a) and after release (b)
123
Arch Orthop Trauma Surg (2015) 135:891–893
893
Discussion
Conclusion
A rarer form among peripheral compression neuropathies, the so-called ‘punched nerve syndrome’, was only recently reliably demonstrated using HRUS in a series of patients. It is thought to arise from repeated pulsatile neural compression by an adjacent vascular structure [7]. The defining characteristics of a PNS are a well-circumscribed hypoechoic enlargement of the neural diameter at the site of a crossing artery. In our patient, who already had undergone decompression surgery of the ulnar nerve at the Guyon’s canal without symptom relief, a pathological neurovascular contact syndrome of the deep ulnar motor branch was revealed by means of HRUS. The patient had displayed persisting dyspraxia and atrophy of the interosseous, hypothenar and thenar muscles. A lack of sensitive deficits and nerve conduction velocity findings in concordance with distal motor neuron damage suggested a site of injury within or distal to the canal of Guyon. Consequently decompression surgery at this site led to improvement of symptoms 6 months after decompression. Thorough history taking and clinical examination is essential in narrowing down possible sites of neural damage in a suspected ulnar tunnel syndrome [5]. An experienced examiner can use HRUS to identify the location and cause of such neural damage through dynamic interaction with the patient.
In this case HRUS could identify the site of compression of the deep ulnar branch in the palm due to a punched nerve syndrome, a rare but noteworthy cause of peripheral compression neuropathies. Conflict of interest
None.
References 1. Kopf H, Loizides A, Mostbeck G, Gruber H (2011) Diagnostic sonography of peripheral nerves: indications, examination techniques and pathological findings. Ultraschall Med 32(3):242–263 2. Latinovic R, Gulliford M, Hughes R (2006) Incidence of common compressive neuropathies in primary care. J Neurol Neurosurg Psychiatry 77(2):263–265 3. Dawson D (1993) Entrapment neuropathies of the upper extremities. N Engl J Med 329(27):2013–2018 4. Beltran J, Rosenberg Z (1994) Diagnosis of compressive and entrapment neuropathies of the upper extremity: value of MR imaging. AJR Am J Roentgenol 163(3):525–531 5. Chen S, Tsai T (2014) Ulnar tunnel syndrome. J Hand Surg Am 39(3):571–579 6. Murata K, Shih J, Tsai T (2003) Causes of ulnar tunnel syndrome: a retrospective study of 31 subjects. J Hand Surg Am 28(4):647–651 7. Loizides A, Peer S, Plaikner M, Djurdjevic T, Gruber H (2012) Punched nerve syndrome: ultrasonographic appearance of functional vascular nerve impairment. Ultraschall Med 33(4):352–356
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