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Childhood lumbosacral plexus neuropathy
Childhood Lumbosacral Plexus Neuropathy
Case Reports
Primary lumbosacral plexus neuropathy (LSPN) is now recognized as a distinct clinical entity similar to idiopathic brachial plexus neuropathy [1-3]. LSPN is a syndrome of unknown pathogenesis characterized by acute pain and weakness localized to 1 limb following a distribution of the lumbosacral plexus. No underlying cause is known; it is unrelated to direct trauma or compression of the nerve trunks. Diagnosis is based on the history, clinical features, characteristic electromyographic (EMG) findings, and exclusion of underlying disease [1]. LSPN generally affects adults and rarely occurs in children. Although 2 previous studies reported its occurrence in younger patients [2,3], LSPN has not been reported in the pediatric literature. We present the clinical and EMG findings in 2 children with LSPN evaluated at our institution and review the literature.
Patient 1. This 21/2-year-old girl developed acute right leg weakness~ Eight days prior to admission, she had a fever of 102°E On the following day, she was examined and treated with amoxicillin (250 mg every 8 hours) for suspected streptococcal pharyngitis. Fever persisted. On the fifth day, she complained of right leg pain and weakness. Pregnancy, labor, delivery, and psychomotor development were normal. There were no prenatal or perinatal complications; there had been no antecedent immunization, trauma, injections, exposure to toxins, or similar familial illness. The general physical examination was unremarkable, including percussion of the spine. Neurologic examination was normal except for the right leg which was flaccid, externally rotated, areflexic, and markedly weak (Medical Research Council Scale-I [MRC]) in the iliopsoas, quadriceps, thigh adductors, dorsiflexors, and plantar flexor muscle groups. Sensation and coordination were normal for age. EMG revealed acute denervation (i.e., fibrillation potentials, reduced number of motor units) in the right quadriceps, iliopsoas, gastrocnemius, adductor magnus, and tibialis anterior mu~les. The lumbosacral paraspinal muscles were spared. Peroneal and tibial motor and sural sensory nerve conduction studies were normal. By the third hospital day, the pain had resolved. Six weeks later, following physical therapy, only mild weakness (MRC-4) was present in the iliopsoas, quadriceps, and tibialis anterior muscles. Deep tendon reflexes were present (2/4). She was able to walk without assistance or braces. A mild genu recurvatum remained. Patient 2. This 14-year-old girl developed acute pain in the right anterior thigh 3 days after a fever of 101°E The pain resolved in 3 days, but she then developed weakness in the right leg. Pregnancy, labor, delivery, and psychomotor development were normal. There were no pre- or perinatal complications. The general physical examination was normal, including spinal percussion and straight leg raising. Neurologic findings were confined to the right leg. There was weakness (MRC-3) of the right itiopsoas and quadriceps muscles with a diminished right patellar reflex (1/4). Sensation was diminished on the anterior lateral aspect of the right thigh in the distribution of the lateral femoral cutaneous nerve. EMG revealed acute denervation (i.e., fibrillation potentials, reduced number of motor units) in the right iliopsoas and quadriceps muscles. EMGs of the paraspinal, left quadriceps, right adductor, tibialis anterior, and gastrocnemius muscle groups were normal. Tibial and peroneal motor and sural sensory nerve conductions were normal. Three days later, sensation was normal. The patient received physical therapy and within 1 month no weakness was present and the patella reflex was normal. In both patients, the following blood tests were normal: complete blood count, erythrocyte sedimentation rate, glucose, blood urea nitrogen, creatinine, electrolytes, liver function tests, creatinine kinase, antinuclear antibodies, rheumatoid factor, complement level, serum protein electrophoresis, vitamin E, lipoprotein electrophoresis, T3, T4, TSH, heavy metal screen, and lead level. Viral titers, including poliomyelitis, Coxsackie, and ECHO, demonstrated no signs of acute infection in either patient. The following tests were also normal in both patients: chest roentgenogram, electrocardiogram, urinalysis, stool cultures for enteric pathogens, lumbosacral spine roentgenograms, MRI of the lumbosacral spine and lumbosacral plexus, and abdominal ultrasound. Cerebrospinal fluid was normal, including opening pressure, cell count, glucose, protein, IgG, and cultures for bacteria, fungus, and tuberculosis.
From the Department of Neurology; Children's Hospital of Michigan; Detroit, Michigan. Presented in part at the 18th annual meeting of the Child Neurology Society; October 12-14, 1989; Sun Antonio, Texas.
Communications should be addressed to: Dr. Awerbuch; 200 South Wenona Street; Suite 298: Bay City, MI 48706. Received June 27, 1989; accepted July 27, 1989.
Gavin I. Awerbuch, MD, Michael A. Nigro, DO, Edward Dabrowski, MD, and Jeffrey R. Levin, MD Primary iumbosacral plexus neuropathy without underlying disease is a well-defined syndrome characterized by pain, weakness, and atrophy in the distribution of the lumbosacral plexus. It generally affects adults and rarely occurs in children. We report 2 children with primary lumbosacral plexus neuropathy evaluated at our institution and review the literature. This syndrome, despite initially severe symptoms, appears to be benign with a favorable prognosis in children.
Awerbuch GI, Nigro MA, Dabrowski E, Levin JR. Childhood lumbosacral plexus neuropathy. Pediatr Neurol 1989;5:314-6.
Introduction
314
PEDIATRIC NEUROLOGY
Vol. 5 No. 5
Table 1. Summary of the clinical features in 5 patients with childhood lumbosacral plexus neuropathy
Patient Number
Age (yrs)/ Sex
Neurologic
Presentation
Time Between Fever and Symptom Onset
Time to Maximal
Degree of Recovery
Recovery
1
21A/F
Painful upper and lower LSPN
8 days
11,4 months
Mild residual weakness
2
14/F
Painful upper LSPN; parasthesias
3 days
1 month
Complete
3
21/2/M
Painful upper LSPN
5 days
2 months
Mild residual weakness
4
3/F
Painful upper LSPN
6 days
1 month
Complete
5
15/F
Painful upper LSPN; paresthesias
None
3 months
75% recovery
Abbreviations: F = Female LSPN = Lumbosacral plexus neuropathy M = Male
Discussion LSPN is a disease entity of unknown origin and must be differentiated from lumbosacral plexus lesions due to neoplastic, traumatic, compressive, infectious, inflammatory, or toxic causes [3]. The disease may involve either the upper, lower, or entire plexus. Several criteria have been established to support the diagnosis of LSPN. These criteria include acute onset in hours to days, occurrence in all age groups, pain in the extremity (often severe without back pain exacerbated by Valsalva maneuver), weakness and atrophy located in the distribution of individual nerves or the plexus, sensory symptoms usually consisting of paresthesias, and early recovery in mild cases or prolonged recovery in severe ones (both with generally good outcomes) [1]. EMG findings of denervation are confined to the distribution of the lumbosacral plexus; however, the paraspinal muscles are spared. No other etiologic factor or cause of neuropathy occurs with this disease. The clinical features in our patients were similar to those reported previously [1-3]. Extensive testing was performed to evaluate lesions in the spinal cord, nerve roots, or lumbosacral plexus. Radiologic investigations failed to identify a structural abnormality of the spinal cord, nerve roots, or plexus. Rapid clinical improvement permitted the exclusion of a progressive disorder (i.e., plexus infiltration or compression). The absence of clinical and laboratory features excluded lumbosacral plexopathy due to trauma, diabetes, vascular lesion, vasculitis, infection, injection, amyloid, sarcoid, or heavy metal intoxication. EMG findings were consistent with LSPN; denervation was present in muscles innervated by peripheral nerves from several lumbosacral segmental levels. The paraspinal muscles were spared.
It has been suggested that LSPN is an equivalent of brachial plexus neuropathy (BPN) due to the clinical similarities and absence of an identifiable cause [2,3]. As in LSPN, BPN may occur at any age, but is uncommon in children. In a series of 99 BPN patients reported by Tsairis et al., only 7 were younger than 20 years of age [4]. Magee and DeJong, reported 8- and 9-year-old boys among their 23 patients with BPN [5]. In 2 previously reported series of patients with LSPN, Sander and Sharp described children 21/2-3 years of age [2], while Evans et al. reported a 15-year-old girl with LSPN [3]. Table 1 summarizes the significant clinical features of these patients as well as Patients 1 and 2. Patients were 2V2-15 years of age and the sex ratio was 4 females:l male. Interval from symptom onset to diagnosis was 3-14 days. In adults, LSPN more commonly involves the upper trunks of the lumbosacral plexus. Similarly, 4 of 5 children (80%) presented with an upper plexus disorder, while 1 patient presented with complete plexus involvement [1,2]. In 4 of the 5 children (80%), onset of LSPN occurred 3-8 days after a febrile illness. Although the pathophysiology of LSPN is unknown, these antecedent events suggest that an undefined viral agent or immune-mediated mechanism may underlie this syndrome; however, this mechanism would not explain the focal damage to the lumbosacral plexus without evidence of a more generalized neuropathy. Despite initially severe pain and weakness, all children had at least a 75% recovery of strength with normal functional recovery. In all patients, pain cessation preceded improvement of strength. LSPN should be considered in children with acute pain and weakness of 1 lower limb when EMG demonstrates evidence of denervation in the distribution of the lum-
Awerbuch et al: Childhood LSPN
315
bosacral plexus without paraspinal muscle involvement. The diagnosis is one of exclusion; however, we believe that invasive diagnostic procedures may be deferred in typical cases when the clinical course parallels the nearly complete, but expected, delayed recovery of function [3]. LSPN in children appears to be a benign syndrome with favorable prognosis despite initially severe symptoms. Accurate diagnosis, reassurance, and the judicious use of analgesics and physical therapy are important in the management of these patients.
316
PEDIATRIC NEUROLOGY
Vol. 5 No. 5
References
[!1 Stevens JC. LumbosacraI plexus lesi,.ms. In: l)\.cl, I'.l Ihoma~, PK, Lambert EH, Bunge R. eds. Peripheral net~ropathy, vol 2. Philadelphia: WB Saunders, 1984:1925-34. [2] Sander JE. Sharp FR. Lumbosacral plexus neuriti,,. Neun~h~gy 1981:31:470-3. [3] Evans BA, Stevens JC, Dyck PJ. LtlmN~sacral pJcxus ~leuropathy. Neurology 1981:31:1327-30. [4] T~iris P. Dyck PJ, Mulder DW. Natural history of hrachial plexus neuropathy. Arch Neurol 1972;27:100-14. [5] Magee KR, DeJong RN. Paralytic brachial neuritis. JAMA 1960; 174:1258-64.
Case Reports
Primary lumbosacral plexus neuropathy (LSPN) is now recognized as a distinct clinical entity similar to idiopathic brachial plexus neuropathy [1-3]. LSPN is a syndrome of unknown pathogenesis characterized by acute pain and weakness localized to 1 limb following a distribution of the lumbosacral plexus. No underlying cause is known; it is unrelated to direct trauma or compression of the nerve trunks. Diagnosis is based on the history, clinical features, characteristic electromyographic (EMG) findings, and exclusion of underlying disease [1]. LSPN generally affects adults and rarely occurs in children. Although 2 previous studies reported its occurrence in younger patients [2,3], LSPN has not been reported in the pediatric literature. We present the clinical and EMG findings in 2 children with LSPN evaluated at our institution and review the literature.
Patient 1. This 21/2-year-old girl developed acute right leg weakness~ Eight days prior to admission, she had a fever of 102°E On the following day, she was examined and treated with amoxicillin (250 mg every 8 hours) for suspected streptococcal pharyngitis. Fever persisted. On the fifth day, she complained of right leg pain and weakness. Pregnancy, labor, delivery, and psychomotor development were normal. There were no prenatal or perinatal complications; there had been no antecedent immunization, trauma, injections, exposure to toxins, or similar familial illness. The general physical examination was unremarkable, including percussion of the spine. Neurologic examination was normal except for the right leg which was flaccid, externally rotated, areflexic, and markedly weak (Medical Research Council Scale-I [MRC]) in the iliopsoas, quadriceps, thigh adductors, dorsiflexors, and plantar flexor muscle groups. Sensation and coordination were normal for age. EMG revealed acute denervation (i.e., fibrillation potentials, reduced number of motor units) in the right quadriceps, iliopsoas, gastrocnemius, adductor magnus, and tibialis anterior mu~les. The lumbosacral paraspinal muscles were spared. Peroneal and tibial motor and sural sensory nerve conduction studies were normal. By the third hospital day, the pain had resolved. Six weeks later, following physical therapy, only mild weakness (MRC-4) was present in the iliopsoas, quadriceps, and tibialis anterior muscles. Deep tendon reflexes were present (2/4). She was able to walk without assistance or braces. A mild genu recurvatum remained. Patient 2. This 14-year-old girl developed acute pain in the right anterior thigh 3 days after a fever of 101°E The pain resolved in 3 days, but she then developed weakness in the right leg. Pregnancy, labor, delivery, and psychomotor development were normal. There were no pre- or perinatal complications. The general physical examination was normal, including spinal percussion and straight leg raising. Neurologic findings were confined to the right leg. There was weakness (MRC-3) of the right itiopsoas and quadriceps muscles with a diminished right patellar reflex (1/4). Sensation was diminished on the anterior lateral aspect of the right thigh in the distribution of the lateral femoral cutaneous nerve. EMG revealed acute denervation (i.e., fibrillation potentials, reduced number of motor units) in the right iliopsoas and quadriceps muscles. EMGs of the paraspinal, left quadriceps, right adductor, tibialis anterior, and gastrocnemius muscle groups were normal. Tibial and peroneal motor and sural sensory nerve conductions were normal. Three days later, sensation was normal. The patient received physical therapy and within 1 month no weakness was present and the patella reflex was normal. In both patients, the following blood tests were normal: complete blood count, erythrocyte sedimentation rate, glucose, blood urea nitrogen, creatinine, electrolytes, liver function tests, creatinine kinase, antinuclear antibodies, rheumatoid factor, complement level, serum protein electrophoresis, vitamin E, lipoprotein electrophoresis, T3, T4, TSH, heavy metal screen, and lead level. Viral titers, including poliomyelitis, Coxsackie, and ECHO, demonstrated no signs of acute infection in either patient. The following tests were also normal in both patients: chest roentgenogram, electrocardiogram, urinalysis, stool cultures for enteric pathogens, lumbosacral spine roentgenograms, MRI of the lumbosacral spine and lumbosacral plexus, and abdominal ultrasound. Cerebrospinal fluid was normal, including opening pressure, cell count, glucose, protein, IgG, and cultures for bacteria, fungus, and tuberculosis.
From the Department of Neurology; Children's Hospital of Michigan; Detroit, Michigan. Presented in part at the 18th annual meeting of the Child Neurology Society; October 12-14, 1989; Sun Antonio, Texas.
Communications should be addressed to: Dr. Awerbuch; 200 South Wenona Street; Suite 298: Bay City, MI 48706. Received June 27, 1989; accepted July 27, 1989.
Gavin I. Awerbuch, MD, Michael A. Nigro, DO, Edward Dabrowski, MD, and Jeffrey R. Levin, MD Primary iumbosacral plexus neuropathy without underlying disease is a well-defined syndrome characterized by pain, weakness, and atrophy in the distribution of the lumbosacral plexus. It generally affects adults and rarely occurs in children. We report 2 children with primary lumbosacral plexus neuropathy evaluated at our institution and review the literature. This syndrome, despite initially severe symptoms, appears to be benign with a favorable prognosis in children.
Awerbuch GI, Nigro MA, Dabrowski E, Levin JR. Childhood lumbosacral plexus neuropathy. Pediatr Neurol 1989;5:314-6.
Introduction
314
PEDIATRIC NEUROLOGY
Vol. 5 No. 5
Table 1. Summary of the clinical features in 5 patients with childhood lumbosacral plexus neuropathy
Patient Number
Age (yrs)/ Sex
Neurologic
Presentation
Time Between Fever and Symptom Onset
Time to Maximal
Degree of Recovery
Recovery
1
21A/F
Painful upper and lower LSPN
8 days
11,4 months
Mild residual weakness
2
14/F
Painful upper LSPN; parasthesias
3 days
1 month
Complete
3
21/2/M
Painful upper LSPN
5 days
2 months
Mild residual weakness
4
3/F
Painful upper LSPN
6 days
1 month
Complete
5
15/F
Painful upper LSPN; paresthesias
None
3 months
75% recovery
Abbreviations: F = Female LSPN = Lumbosacral plexus neuropathy M = Male
Discussion LSPN is a disease entity of unknown origin and must be differentiated from lumbosacral plexus lesions due to neoplastic, traumatic, compressive, infectious, inflammatory, or toxic causes [3]. The disease may involve either the upper, lower, or entire plexus. Several criteria have been established to support the diagnosis of LSPN. These criteria include acute onset in hours to days, occurrence in all age groups, pain in the extremity (often severe without back pain exacerbated by Valsalva maneuver), weakness and atrophy located in the distribution of individual nerves or the plexus, sensory symptoms usually consisting of paresthesias, and early recovery in mild cases or prolonged recovery in severe ones (both with generally good outcomes) [1]. EMG findings of denervation are confined to the distribution of the lumbosacral plexus; however, the paraspinal muscles are spared. No other etiologic factor or cause of neuropathy occurs with this disease. The clinical features in our patients were similar to those reported previously [1-3]. Extensive testing was performed to evaluate lesions in the spinal cord, nerve roots, or lumbosacral plexus. Radiologic investigations failed to identify a structural abnormality of the spinal cord, nerve roots, or plexus. Rapid clinical improvement permitted the exclusion of a progressive disorder (i.e., plexus infiltration or compression). The absence of clinical and laboratory features excluded lumbosacral plexopathy due to trauma, diabetes, vascular lesion, vasculitis, infection, injection, amyloid, sarcoid, or heavy metal intoxication. EMG findings were consistent with LSPN; denervation was present in muscles innervated by peripheral nerves from several lumbosacral segmental levels. The paraspinal muscles were spared.
It has been suggested that LSPN is an equivalent of brachial plexus neuropathy (BPN) due to the clinical similarities and absence of an identifiable cause [2,3]. As in LSPN, BPN may occur at any age, but is uncommon in children. In a series of 99 BPN patients reported by Tsairis et al., only 7 were younger than 20 years of age [4]. Magee and DeJong, reported 8- and 9-year-old boys among their 23 patients with BPN [5]. In 2 previously reported series of patients with LSPN, Sander and Sharp described children 21/2-3 years of age [2], while Evans et al. reported a 15-year-old girl with LSPN [3]. Table 1 summarizes the significant clinical features of these patients as well as Patients 1 and 2. Patients were 2V2-15 years of age and the sex ratio was 4 females:l male. Interval from symptom onset to diagnosis was 3-14 days. In adults, LSPN more commonly involves the upper trunks of the lumbosacral plexus. Similarly, 4 of 5 children (80%) presented with an upper plexus disorder, while 1 patient presented with complete plexus involvement [1,2]. In 4 of the 5 children (80%), onset of LSPN occurred 3-8 days after a febrile illness. Although the pathophysiology of LSPN is unknown, these antecedent events suggest that an undefined viral agent or immune-mediated mechanism may underlie this syndrome; however, this mechanism would not explain the focal damage to the lumbosacral plexus without evidence of a more generalized neuropathy. Despite initially severe pain and weakness, all children had at least a 75% recovery of strength with normal functional recovery. In all patients, pain cessation preceded improvement of strength. LSPN should be considered in children with acute pain and weakness of 1 lower limb when EMG demonstrates evidence of denervation in the distribution of the lum-
Awerbuch et al: Childhood LSPN
315
bosacral plexus without paraspinal muscle involvement. The diagnosis is one of exclusion; however, we believe that invasive diagnostic procedures may be deferred in typical cases when the clinical course parallels the nearly complete, but expected, delayed recovery of function [3]. LSPN in children appears to be a benign syndrome with favorable prognosis despite initially severe symptoms. Accurate diagnosis, reassurance, and the judicious use of analgesics and physical therapy are important in the management of these patients.
316
PEDIATRIC NEUROLOGY
Vol. 5 No. 5
References
[!1 Stevens JC. LumbosacraI plexus lesi,.ms. In: l)\.cl, I'.l Ihoma~, PK, Lambert EH, Bunge R. eds. Peripheral net~ropathy, vol 2. Philadelphia: WB Saunders, 1984:1925-34. [2] Sander JE. Sharp FR. Lumbosacral plexus neuriti,,. Neun~h~gy 1981:31:470-3. [3] Evans BA, Stevens JC, Dyck PJ. LtlmN~sacral pJcxus ~leuropathy. Neurology 1981:31:1327-30. [4] T~iris P. Dyck PJ, Mulder DW. Natural history of hrachial plexus neuropathy. Arch Neurol 1972;27:100-14. [5] Magee KR, DeJong RN. Paralytic brachial neuritis. JAMA 1960; 174:1258-64.