20
Journal of
CLINICAL NEUROMUSCULAR DISEASE
Case Review
Volume 16, Number 1 September 2014
Rare Case of a Localized Radial Nerve Amyloid Neuropathy Martin Kanta, MD, PhD,* Edvard Ehler, MD, PhD,† Aleš Kohout, MD, PhD,‡ Jir ina Habalová, MD, PhD,* Roman Hanácek, MD,* Oldr ich Vyšata, MD, PhD,§ Jindra Brtková, MD, PhD,¶ ehák, MD, PhD,* and Martin Vališ, MD, PhD§ Stanislav R
Abstract We report the case of a 55-year-old woman with a 6-month history of progressive paresis of the right radial nerve. Perioperative imaging detected a spindle-shaped expansion of the radial nerve caused by an isolated local deposit of amyloid (amyloidoma). The deposit was resected in 2 phases and the resulting defect was bridged by a sural nerve autograft. Overall internal and hematological examination did not reveal systemic amyloidosis or lymphoproliferative disorder. The reason for our report is that localized forms of amyloid neuropathy are very rare. From the *Department of Neurosurgery, Faculty of Medicine, University Hospital Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic; †Department of Neurology, Pardubice Regional Hospital, Pardubice, Czech Republic; ‡The Fingerland Department of Pathology, Faculty of Medicine, University Hospital Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic; and Departments of §Neurology, and ¶Radiology, Faculty of Medicine, University Hospital Hradec Králové, Charles University in Prague, Hradec Kralove, Czech Republic. Supported by MH CZ-DRO (UHHK, 00179906). The authors report no conflicts of interest. Reprints: Martin Vališ, MD, PhD, Department of Neurology, Faculty of Medicine and University Hospital Hradec Králové Charles University in Prague, Sokolska 581, Hradec Kralove 500 05, Czech Republic (e-mail: [email protected]). Copyright © 2014 by Lippincott Williams & Wilkins
Key Words: peripheral nerve, amyloidosis, neuropathy
( J Clin Neuromusc Dis 2014;16:20–23)
INTRODUCTION In amyloidosis, pathogenic amyloid protein is accumulated in extracellular space of tissues and organs. Amyloid is not a chemically distinct entity while accounting for a heterogeneous group of different proteins with a common feature of beta-sheet conformation. Peripheral nerves can be damaged due to primary systemic amyloidosis associated with lymphoproliferative disorders (AL amyloidosis, where the amyloid deposits comprise immunoglobulin light-chain proteins), hereditary familial amyloid polyneuropathy caused by mutations in the genes coding for transthyretin, or infrequently, gelsolin or apolipoprotein A1.1 Secondary amyloidosis (AA amyloidosis occurring as a complication in the course of chronic inflammatory disease) does not result in the damage of peripheral nerves.2 Peripheral
nerve amyloidoma (macroscopically visible isolated local amyloid accumulation) is a very uncommon condition, and it is mostly formed by polymerized immunoglobulin light-chain proteins in the course of localized or systemic clonal proliferation of plasma cells.3
CASE REPORT A 55-year-old woman complained of impaired right hand motility lasting for 5 months (since December 2009). Neurological examination revealed severe paresis with the swan-neck deformity while the ability of the patient to extend her hand at the carpal and metacarpal joints was only hardly noticeable. Electromyography (EMG) examination detected marked impairment of the radial nerve in the arm. Nerve conduction of the superficial radial nerve could not be stimulated. Needle EMG was with subacute moderate-tosevere lesions in the examined muscles. Magnetic resonance (MR) imaging exposed a 6-cm long spindle-shaped expansion in the middle zone of the arm (distal pole of the process was 7 cm from the elbow joint space, 13 cm proximal from the elbow), which was T1 hypointense and only moderately T2 hyperintense as compared with the surrounding muscle tissue. The radial nerve, axially projecting from this structure, was mildly incrassated. The expansion was longitudinally homogenous and on section finely grained (Fig. 1). On May 26, 2010, inspection and preparation of the pathologically altered nerve segment was performed under total anesthesia.
Localized Radial Nerve Amyloid Neuropathy
Individual fascicles were indistinguishable from the pathologic tissue diffusely infiltrating the nerve. Therefore, to preserve some of the fascicles, only partial resection of the nidus was implemented. Based on the MR imaging and macroscopic morphology of the lesion, neurofibroma was suspected. Histological analysis of the resected tissue, however, revealed that the nerve incrassation resulted from a massive accumulation of amyloid in
endoneurium, perineurium, and around blood vessels, which caused pronounced disorganization of the nerve fascicles. After the surgery, the radial nerve paresis further deteriorated and presented as plegia. Because of operational finding of virtually indistinguishable fascicles from pathological tissues, histological diagnosis, and postoperative deterioration in full plegia after the first operation, we decided not to wait for the eventual spontaneous reinnervation, and we came to a quick solution, that is, a complete resection with graft replacement. Since the preserved fascicles did not enable spontaneous regeneration and reinnervation, a broad nerve resection including areas flanking macroscopically visible borders of the amyloid and a bypass of the resulting defect (8 cm long) using 3 grafts from sural nerve was performed on June 7, 2010. The histological analysis of the excised tissue confirmed the presence of amyloid deposits in the nerve. Moreover, while collecting the grafts from sural nerve, amyloid surrounding this nerve was detected. A detailed internal and hematological follow-up examination (which included biopsies of buccal mucosa, rectum, liver, and bone marrow) did indicate no systemic amyloidosis or lymphoproliferative disorder. Further imaging (ultrasonography and MR) did not reveal additional damaged sites in the patient. After discharge from the hospital, the patient underwent long-term rehabilitation (18 months) with amelioration of the radial nerve paresis (able to extend the wrist and noticeable extension at the metacarpophalangeal joints). A series of EMG examinations within 3 years showed gradual reinnervation of the radial nerve. Recently, the patient is self-sufficient and returned to her previous occupation (accountant in a family-owned business).
DISCUSSION FIGURE 1. MRI: T2-weighted coronal: somewhat irregular spindle-shaped mass longitudinally infiltrating the radial nerve in the lateral intermuscular septum of the right arm.
Amyloid can be deposited in any part of the peripheral nervous system (peripheral nerves, plexi, sensory, and autonomic ganglia). www.jcnmd.com
Journal of
CLINICAL NEUROMUSCULAR DISEASE Volume 16, Number 1 September 2014
21
22
Journal of
CLINICAL NEUROMUSCULAR DISEASE
Volume 16, Number 1 September 2014
Kanta et al
It forms extracellular deposits of amorphous eosinophilic material with specific staining patterns caused by the molecular structure of beta-sheet (positive for Congo red, Saturn red, and Gentian violet staining). In the peripheral nerve, amyloid accumulates mainly in the endoneurium and in the walls of blood vessels. Nerve fibers gradually degenerate while initially, mainly small myelinated and nonmyelinated fibers are affected, and in later stages, diffuse damage of all fiber types occurs.4 The exact mechanism of the nerve fibers impairment is not completely known.5 There is a possibility of ischemic damage resulting from the stenosis of blood vessels infiltrated by amyloid. However, mainly small nerve fibers that are relatively resistant to ischemic damage are affected. Another possibility is a direct compression of the nerve fibers by amyloid deposits in the endoneurium, whereas large nerve fibers are protected by myelin sheaths. Moreover, the toxic effect of amyloid on nerve fibers had been suggested. Isolated impairment of peripheral nerves by amyloid forming a tumor-like nerve expansion (so-called amyloidoma) is extremely rare. In most of the cases, it is associated with one of the forms of plasma cell dyscrasia (plasmacytoma, monoclonal gammopathy) and the amyloid is formed by polymerized immunoglobulin light-chain proteins. It can be also infrequently caused by other amyloid types such as apolipoprotein A1.3 In our case, the amyloid type has not been identified by immunohistochemical analysis (antibodies against AA amyloid, kappa and lambda light chains, and transthyretin were used). Isolated peripheral nerve amyloidosis is a rare condition leading to nerve degeneration and dysfunction. It is important to distinguish it from the relatively common impairment of peripheral nerves in the course of systemic amyloidosis (Table 1).6 Accumulation of amyloid deposits in nerves can lead to focal, multifocal, or diffuse forms of neuropathy. Both primary and familial forms of amyloidosis result in polyneuropathy, and as for its focal forms, only the carpal tunnel syndrome with local amyloid accumulation usually develops. Lesions of brachial and lumbosacral plexus or © 2014 Lippincott Williams & Wilkins
large nerves in limbs are rare.3 However, case reports on amyloid neuropathy with focal mononeuropathy-like impairment of individual nerves—recurrent laryngeal nerve, have been published.7 Typical symptoms of amyloid neuropathy are caused by the damage of sensory and autonomic fibers and include painful paresthesia, lack of sensation, and posture disturbance (caused by damage of sensory fibers). Impairment of autonomic fibers usually leads to nausea, vomiting, diarrhea, incontinence, swallowing difficulties, and sexual dysfunction.8 The low incidence of amyloid polyneuropathy was documented by Rajani et al,9 who found that of 1098 sural nerve biopsies (within 15 years), amyloid deposits occurred only in 13 patients (1.2%). In primary amyloidosis, however, polyneuropathy occurs in up to 30% of patients. Polyneuropathy in lower limbs is length dependent with the deterioration of the longest fascicles and occurs in 25% of patients. In 20% of patients, trunk impairment with asymmetric mononeuritis multiplex-like distribution is also present. Carpal tunnel syndrome develops in 25% of patients; focal impairment of upper limbs or cranial nerves (particularly the facial nerve) is rare.6 In our large cohort of patients operated for different lesions of peripheral nerves, the case reported here is the first of its kind. Imaging methods (ultrasonography and MR) simply recognized the spindleshaped expansion of the nerve, whose nature was revealed only by histological and histochemical analysis. When amyloid neuropathy is detected, it is necessary to always explore whether a systemic disorder is present.9 We recommend performing liver, kidney, rectal, gastric, abdominal fat, salivary glands, and muscle or skin biopsy.6 Our patient reported no symptoms of typical autonomic difficulties, which would indicate systemic involvement (fainting, postural hypertension, constipation or diarrhea, and sweating abnormalities), and a detailed internal examination confirmed the absence of systemic amyloidosis. Nevertheless, we consider her long-term monitoring for this purpose profitable. Despite the presence of amyloid deposits around the sural
Localized Radial Nerve Amyloid Neuropathy
Journal of
CLINICAL NEUROMUSCULAR DISEASE Volume 16, Number 1 September 2014
TABLE 1. Amyloid Neuropathies Acquired Familial amyloid polyneuropathy (FAP)
Primary (AL) amyloidosis Secondary (AA) amyloidosis Transthyretin amyloidosis (FAP types I and II) Apolipoproteinu A1 amyloidosis (FAP type III or Van Allen type) Gelsolin amyloidosis (FAP type IV, Finnish type)
nerve, the patient had no further clinical signs of amyloid neuropathy in addition to the above-mentioned paresis of radial nerve. Recently, her condition keeps ameliorating rather significantly—the motility of the right hand periphery improves, the patient returned to her previous occupation (accountant) and is self-sufficient. After injury, the radial nerve is able to regenerate very well with superior reinnervation often achieved even with long grafts for nerve bridging. In our case, despite the presence of the amyloid around the sural nerve used to obtain the grafts, the motility of the hand is gradually improving. However, total recovery is slower when compared with other cases with simple injury of the radial nerve. This can result from the length of the defect and possible spreading of the impairment peripherally or centrally from the resected area. The remaining questions are how will the regeneration continue, whether the nerve will be fully functional and whether the disease will reappear locally or in other large nerves in the limbs and whether symptoms of a systemic disease occur. There are no answers to these questions available in the literature. In some patients with radial nerve injury, tendon transfers are recommended when the reinnervation is not successful.10 This treatment option was however rejected by the patient.
CONCLUSIONS The authors present here a rare case of a clinically manifested mononeuropathy of the radial nerve in the arm area caused by amyloid. REFERENCES 1. Bilbao JM, Schmidt R, Hawkins C. Diseases of peripheral nerve. In: Love S, Louis DN, Ellison DW, eds. Greenfield’s Neuropathology. 8th ed. London, United Kingdom: Hodder Arnold; 2008:1675–1681. 2. Falk RH, Comenzo RL, Skinner M. The systemic amyloidosis. N Engl J Med. 1997;337:898–909. 3. Loavenbruck AJ, Chaudry V, Zeldenrust SR, et al. Mass spectrum analysis reveals non-mutated apolipoprotein A1 lumbosacral radioplexus amyloidoma. Muscle Nerve. 2012;46:817–822. 4. Dyck PJ, Lambert EH. Dissociated sensation in amyloidosis: compound action potentials; quantitative histologic and teased fibers and electron microscopic studies of sural nerve biopsies. Trans Am Neurol Assoc. 1968;93:112–115. 5. Adams D. Hereditary and acquired amyloid neuropathies. J Neurol. 2001;248:647–657. 6. Amato AA, Russel JA. Neuromuscular Disorders. New York, NY: McGraw Hill Medical; 2008. 7. Conaghan P, Chung D, Vaughan R. Case report. Recurrent laryngeal nerve palsy associated with mediastinal amyloidosis Thorax. 2000;55:436–437. 8. Subramanian K, Sivaprakash, Harris M, et al. A rare presentation of primary (AL) amyloidosis. Ann Indian Acad Neurol. 2006;9:169–171. 9. Rajani B, Rajani V, Prayson RA. Peripheral nerve amyloidosis in sural nerve biopsies. Arch Pathol Lab Med. 2000;124:114–118. 10. Čižmár I, Ehler E, Pilný J, et al. Radial nerve lesions and the possibilities of functional reconstruction using late tendon transfer. Cesk Slov Neurol N. 2010;73:701–705.
www.jcnmd.com
23
Journal of
CLINICAL NEUROMUSCULAR DISEASE
Case Review
Volume 16, Number 1 September 2014
Rare Case of a Localized Radial Nerve Amyloid Neuropathy Martin Kanta, MD, PhD,* Edvard Ehler, MD, PhD,† Aleš Kohout, MD, PhD,‡ Jir ina Habalová, MD, PhD,* Roman Hanácek, MD,* Oldr ich Vyšata, MD, PhD,§ Jindra Brtková, MD, PhD,¶ ehák, MD, PhD,* and Martin Vališ, MD, PhD§ Stanislav R
Abstract We report the case of a 55-year-old woman with a 6-month history of progressive paresis of the right radial nerve. Perioperative imaging detected a spindle-shaped expansion of the radial nerve caused by an isolated local deposit of amyloid (amyloidoma). The deposit was resected in 2 phases and the resulting defect was bridged by a sural nerve autograft. Overall internal and hematological examination did not reveal systemic amyloidosis or lymphoproliferative disorder. The reason for our report is that localized forms of amyloid neuropathy are very rare. From the *Department of Neurosurgery, Faculty of Medicine, University Hospital Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic; †Department of Neurology, Pardubice Regional Hospital, Pardubice, Czech Republic; ‡The Fingerland Department of Pathology, Faculty of Medicine, University Hospital Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic; and Departments of §Neurology, and ¶Radiology, Faculty of Medicine, University Hospital Hradec Králové, Charles University in Prague, Hradec Kralove, Czech Republic. Supported by MH CZ-DRO (UHHK, 00179906). The authors report no conflicts of interest. Reprints: Martin Vališ, MD, PhD, Department of Neurology, Faculty of Medicine and University Hospital Hradec Králové Charles University in Prague, Sokolska 581, Hradec Kralove 500 05, Czech Republic (e-mail: [email protected]). Copyright © 2014 by Lippincott Williams & Wilkins
Key Words: peripheral nerve, amyloidosis, neuropathy
( J Clin Neuromusc Dis 2014;16:20–23)
INTRODUCTION In amyloidosis, pathogenic amyloid protein is accumulated in extracellular space of tissues and organs. Amyloid is not a chemically distinct entity while accounting for a heterogeneous group of different proteins with a common feature of beta-sheet conformation. Peripheral nerves can be damaged due to primary systemic amyloidosis associated with lymphoproliferative disorders (AL amyloidosis, where the amyloid deposits comprise immunoglobulin light-chain proteins), hereditary familial amyloid polyneuropathy caused by mutations in the genes coding for transthyretin, or infrequently, gelsolin or apolipoprotein A1.1 Secondary amyloidosis (AA amyloidosis occurring as a complication in the course of chronic inflammatory disease) does not result in the damage of peripheral nerves.2 Peripheral
nerve amyloidoma (macroscopically visible isolated local amyloid accumulation) is a very uncommon condition, and it is mostly formed by polymerized immunoglobulin light-chain proteins in the course of localized or systemic clonal proliferation of plasma cells.3
CASE REPORT A 55-year-old woman complained of impaired right hand motility lasting for 5 months (since December 2009). Neurological examination revealed severe paresis with the swan-neck deformity while the ability of the patient to extend her hand at the carpal and metacarpal joints was only hardly noticeable. Electromyography (EMG) examination detected marked impairment of the radial nerve in the arm. Nerve conduction of the superficial radial nerve could not be stimulated. Needle EMG was with subacute moderate-tosevere lesions in the examined muscles. Magnetic resonance (MR) imaging exposed a 6-cm long spindle-shaped expansion in the middle zone of the arm (distal pole of the process was 7 cm from the elbow joint space, 13 cm proximal from the elbow), which was T1 hypointense and only moderately T2 hyperintense as compared with the surrounding muscle tissue. The radial nerve, axially projecting from this structure, was mildly incrassated. The expansion was longitudinally homogenous and on section finely grained (Fig. 1). On May 26, 2010, inspection and preparation of the pathologically altered nerve segment was performed under total anesthesia.
Localized Radial Nerve Amyloid Neuropathy
Individual fascicles were indistinguishable from the pathologic tissue diffusely infiltrating the nerve. Therefore, to preserve some of the fascicles, only partial resection of the nidus was implemented. Based on the MR imaging and macroscopic morphology of the lesion, neurofibroma was suspected. Histological analysis of the resected tissue, however, revealed that the nerve incrassation resulted from a massive accumulation of amyloid in
endoneurium, perineurium, and around blood vessels, which caused pronounced disorganization of the nerve fascicles. After the surgery, the radial nerve paresis further deteriorated and presented as plegia. Because of operational finding of virtually indistinguishable fascicles from pathological tissues, histological diagnosis, and postoperative deterioration in full plegia after the first operation, we decided not to wait for the eventual spontaneous reinnervation, and we came to a quick solution, that is, a complete resection with graft replacement. Since the preserved fascicles did not enable spontaneous regeneration and reinnervation, a broad nerve resection including areas flanking macroscopically visible borders of the amyloid and a bypass of the resulting defect (8 cm long) using 3 grafts from sural nerve was performed on June 7, 2010. The histological analysis of the excised tissue confirmed the presence of amyloid deposits in the nerve. Moreover, while collecting the grafts from sural nerve, amyloid surrounding this nerve was detected. A detailed internal and hematological follow-up examination (which included biopsies of buccal mucosa, rectum, liver, and bone marrow) did indicate no systemic amyloidosis or lymphoproliferative disorder. Further imaging (ultrasonography and MR) did not reveal additional damaged sites in the patient. After discharge from the hospital, the patient underwent long-term rehabilitation (18 months) with amelioration of the radial nerve paresis (able to extend the wrist and noticeable extension at the metacarpophalangeal joints). A series of EMG examinations within 3 years showed gradual reinnervation of the radial nerve. Recently, the patient is self-sufficient and returned to her previous occupation (accountant in a family-owned business).
DISCUSSION FIGURE 1. MRI: T2-weighted coronal: somewhat irregular spindle-shaped mass longitudinally infiltrating the radial nerve in the lateral intermuscular septum of the right arm.
Amyloid can be deposited in any part of the peripheral nervous system (peripheral nerves, plexi, sensory, and autonomic ganglia). www.jcnmd.com
Journal of
CLINICAL NEUROMUSCULAR DISEASE Volume 16, Number 1 September 2014
21
22
Journal of
CLINICAL NEUROMUSCULAR DISEASE
Volume 16, Number 1 September 2014
Kanta et al
It forms extracellular deposits of amorphous eosinophilic material with specific staining patterns caused by the molecular structure of beta-sheet (positive for Congo red, Saturn red, and Gentian violet staining). In the peripheral nerve, amyloid accumulates mainly in the endoneurium and in the walls of blood vessels. Nerve fibers gradually degenerate while initially, mainly small myelinated and nonmyelinated fibers are affected, and in later stages, diffuse damage of all fiber types occurs.4 The exact mechanism of the nerve fibers impairment is not completely known.5 There is a possibility of ischemic damage resulting from the stenosis of blood vessels infiltrated by amyloid. However, mainly small nerve fibers that are relatively resistant to ischemic damage are affected. Another possibility is a direct compression of the nerve fibers by amyloid deposits in the endoneurium, whereas large nerve fibers are protected by myelin sheaths. Moreover, the toxic effect of amyloid on nerve fibers had been suggested. Isolated impairment of peripheral nerves by amyloid forming a tumor-like nerve expansion (so-called amyloidoma) is extremely rare. In most of the cases, it is associated with one of the forms of plasma cell dyscrasia (plasmacytoma, monoclonal gammopathy) and the amyloid is formed by polymerized immunoglobulin light-chain proteins. It can be also infrequently caused by other amyloid types such as apolipoprotein A1.3 In our case, the amyloid type has not been identified by immunohistochemical analysis (antibodies against AA amyloid, kappa and lambda light chains, and transthyretin were used). Isolated peripheral nerve amyloidosis is a rare condition leading to nerve degeneration and dysfunction. It is important to distinguish it from the relatively common impairment of peripheral nerves in the course of systemic amyloidosis (Table 1).6 Accumulation of amyloid deposits in nerves can lead to focal, multifocal, or diffuse forms of neuropathy. Both primary and familial forms of amyloidosis result in polyneuropathy, and as for its focal forms, only the carpal tunnel syndrome with local amyloid accumulation usually develops. Lesions of brachial and lumbosacral plexus or © 2014 Lippincott Williams & Wilkins
large nerves in limbs are rare.3 However, case reports on amyloid neuropathy with focal mononeuropathy-like impairment of individual nerves—recurrent laryngeal nerve, have been published.7 Typical symptoms of amyloid neuropathy are caused by the damage of sensory and autonomic fibers and include painful paresthesia, lack of sensation, and posture disturbance (caused by damage of sensory fibers). Impairment of autonomic fibers usually leads to nausea, vomiting, diarrhea, incontinence, swallowing difficulties, and sexual dysfunction.8 The low incidence of amyloid polyneuropathy was documented by Rajani et al,9 who found that of 1098 sural nerve biopsies (within 15 years), amyloid deposits occurred only in 13 patients (1.2%). In primary amyloidosis, however, polyneuropathy occurs in up to 30% of patients. Polyneuropathy in lower limbs is length dependent with the deterioration of the longest fascicles and occurs in 25% of patients. In 20% of patients, trunk impairment with asymmetric mononeuritis multiplex-like distribution is also present. Carpal tunnel syndrome develops in 25% of patients; focal impairment of upper limbs or cranial nerves (particularly the facial nerve) is rare.6 In our large cohort of patients operated for different lesions of peripheral nerves, the case reported here is the first of its kind. Imaging methods (ultrasonography and MR) simply recognized the spindleshaped expansion of the nerve, whose nature was revealed only by histological and histochemical analysis. When amyloid neuropathy is detected, it is necessary to always explore whether a systemic disorder is present.9 We recommend performing liver, kidney, rectal, gastric, abdominal fat, salivary glands, and muscle or skin biopsy.6 Our patient reported no symptoms of typical autonomic difficulties, which would indicate systemic involvement (fainting, postural hypertension, constipation or diarrhea, and sweating abnormalities), and a detailed internal examination confirmed the absence of systemic amyloidosis. Nevertheless, we consider her long-term monitoring for this purpose profitable. Despite the presence of amyloid deposits around the sural
Localized Radial Nerve Amyloid Neuropathy
Journal of
CLINICAL NEUROMUSCULAR DISEASE Volume 16, Number 1 September 2014
TABLE 1. Amyloid Neuropathies Acquired Familial amyloid polyneuropathy (FAP)
Primary (AL) amyloidosis Secondary (AA) amyloidosis Transthyretin amyloidosis (FAP types I and II) Apolipoproteinu A1 amyloidosis (FAP type III or Van Allen type) Gelsolin amyloidosis (FAP type IV, Finnish type)
nerve, the patient had no further clinical signs of amyloid neuropathy in addition to the above-mentioned paresis of radial nerve. Recently, her condition keeps ameliorating rather significantly—the motility of the right hand periphery improves, the patient returned to her previous occupation (accountant) and is self-sufficient. After injury, the radial nerve is able to regenerate very well with superior reinnervation often achieved even with long grafts for nerve bridging. In our case, despite the presence of the amyloid around the sural nerve used to obtain the grafts, the motility of the hand is gradually improving. However, total recovery is slower when compared with other cases with simple injury of the radial nerve. This can result from the length of the defect and possible spreading of the impairment peripherally or centrally from the resected area. The remaining questions are how will the regeneration continue, whether the nerve will be fully functional and whether the disease will reappear locally or in other large nerves in the limbs and whether symptoms of a systemic disease occur. There are no answers to these questions available in the literature. In some patients with radial nerve injury, tendon transfers are recommended when the reinnervation is not successful.10 This treatment option was however rejected by the patient.
CONCLUSIONS The authors present here a rare case of a clinically manifested mononeuropathy of the radial nerve in the arm area caused by amyloid. REFERENCES 1. Bilbao JM, Schmidt R, Hawkins C. Diseases of peripheral nerve. In: Love S, Louis DN, Ellison DW, eds. Greenfield’s Neuropathology. 8th ed. London, United Kingdom: Hodder Arnold; 2008:1675–1681. 2. Falk RH, Comenzo RL, Skinner M. The systemic amyloidosis. N Engl J Med. 1997;337:898–909. 3. Loavenbruck AJ, Chaudry V, Zeldenrust SR, et al. Mass spectrum analysis reveals non-mutated apolipoprotein A1 lumbosacral radioplexus amyloidoma. Muscle Nerve. 2012;46:817–822. 4. Dyck PJ, Lambert EH. Dissociated sensation in amyloidosis: compound action potentials; quantitative histologic and teased fibers and electron microscopic studies of sural nerve biopsies. Trans Am Neurol Assoc. 1968;93:112–115. 5. Adams D. Hereditary and acquired amyloid neuropathies. J Neurol. 2001;248:647–657. 6. Amato AA, Russel JA. Neuromuscular Disorders. New York, NY: McGraw Hill Medical; 2008. 7. Conaghan P, Chung D, Vaughan R. Case report. Recurrent laryngeal nerve palsy associated with mediastinal amyloidosis Thorax. 2000;55:436–437. 8. Subramanian K, Sivaprakash, Harris M, et al. A rare presentation of primary (AL) amyloidosis. Ann Indian Acad Neurol. 2006;9:169–171. 9. Rajani B, Rajani V, Prayson RA. Peripheral nerve amyloidosis in sural nerve biopsies. Arch Pathol Lab Med. 2000;124:114–118. 10. Čižmár I, Ehler E, Pilný J, et al. Radial nerve lesions and the possibilities of functional reconstruction using late tendon transfer. Cesk Slov Neurol N. 2010;73:701–705.
www.jcnmd.com
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