Parkinsonism and Related Disorders 21 (2015) 343e344
Contents lists available at ScienceDirect
Parkinsonism and Related Disorders journal homepage: www.elsevier.com/locate/parkreldis
Letter to the Editor
Involuntary shoulder jerks after iatrogenic Thoraco-dorsal nerve injury Keywords: Peripheral induced movement disorders Latissimus dorsi Botulinum toxin Shoulder dyskinesia
Peripherally induced movement disorders (PIMDs) represent a rare and so far poorly understood entity. PIMDs encompass a broad spectrum of clinical phenotypes, which includes dystonia, myoclonus, tremor and other hyperkinetic disorders, sometimes combined in a complex mixture of movement features difficult to characterize [1,2]. Here we describe a patient who developed involuntary jerks involving the shoulder girdle 24 years after an iatrogenic nerve traumatism. A 65 year-old lady suffered from right breast carcinoma at the age of 41, for which she underwent radical mastectomy followed by an unsuccessful surgical procedure of breast reconstruction with a pedicled myocutaneous right Latissimus Dorsi (LD) flap. Neither chemotherapy nor radiotherapy were performed. The patient has been regularly followed up without evidence of disease relapse so far. Twenty-four years later she subtly developed an irregular, low amplitude, involuntary twitching of her transposed right LD muscle. No triggers could induce or relieve the movements, which also persisted during sleep. Five months later her condition worsened. The abnormal movements spread to part of the shoulder girdle muscles of the same side, causing a significant impairment of arm utilization in daily-life activities. At the time of presentation to our department, the neurological examination showed continuous, irregular, high amplitude movements of retropulsion, abduction, elevation of the right shoulder girdle and arm flexion, sometimes with a circular component (Video 1, Segment 1). Proximal active movements of the arm could momentarily reduce the amplitude of the muscular jerks, while distal upper extremity tasks had no effect on the movements. During sleep, twitching confined exclusively to the LD. Neurological examination was otherwise unremarkable. Supplementary video related to this article can be found at http://dx.doi.org/10.1016/j.parkreldis.2015.01.003. Blood tests, head computed tomography scan and cervical magnetic resonance imaging were negative. In particular, there was no evidence of disk herniation, nor neuroforaminal stenosis at C5-8 levels on the right side. Needle electromyography (EMG) showed the presence of irregular polymorphic bursts at rest on right LD, Pectoralis Major, Deltoid and Trapezius muscles. Bursts lasted 100e800 ms, with a frequency comprised between 0.5 and 5 Hz. Needle EMG analysis of voluntary activity showed a mild to moderate degree of reduction in the recruitment of motor units in the LD http://dx.doi.org/10.1016/j.parkreldis.2015.01.003 1353-8020/© 2015 Elsevier Ltd. All rights reserved.
muscle, with an increase in amplitude and duration of potentials. On the other hand, a full interference pattern was recorded from all other muscles. Standard electroencephalography (EEG) was normal. EEG-EMG polygraphy revealed that LD was always the first firing muscle. In most circumstances the activation pattern proceeded then to Deltoid and to Trapezius. The delay between LD and Deltoid firing was comprised between 120 and 130 ms, while the delay between Deltoid and Trapezius activation ranged from 20 to 30 ms. Initially hypothesizing a spinal-originating diskyinesia, the patient was started on Clonazepam up to 6 mg/day. This drug produced a significant reduction on the amplitude and frequency of the jerks (Video 1, Segment 2). However, LD movements were not substantially affected. Owing to the suspicion of a peripheral trigger for the involuntary movements, we decided to inject that muscle with 300 units of botulinum toxin type A. Jerks did not improve. Three months later, we again administrated a total of 400 units to the muscle, with almost complete resolution of the jerks in two weeks' time (Video 1, Segment 3). This effect vanished about three months later, but was readily resumed after a further botulinum toxin injection. In this patient a hyperkinetic movement disorder developed 24 years after a surgical intervention of mastectomy and LD flap, during which it is likely that the right Thoracodorsal nerve sustained a partial injury, since we had EMG evidence of isolated chronic reinnervation on LD muscle. Absence of cervical MRI lesions and the pattern of jerks spreading on EMG poligraphy represent additional proofs in favor of a peripheral generator for the abnormal movements. The interval between peripheral injury and PIMDs onset is usually less than one year, but longer latencies have been sporadically reported [1]. The pathogenic mechanisms underlying the generation of movement disorders after peripheral nerve lesions are debated. Injury of the peripheral nerve may lead to spontaneous electrical activities of intramuscular nerve fibers and entryereentry circuits [3]. Successively spinal and maybe supraspinal remodeling ensues. A good example for this is probably represented by the so-called “jumpy stump” [4]. Indeed, in the case of partly amputated limbs, the injured peripheral nerve produces abnormal sensory inputs, which are responsible for a reorganization in the spinal circuitry. The final result of the process is an increase in motor neuron excitability. In our case we hypothesize the state of abnormal excitability was not confined to intramuscular nerve fibers, but involved motor neurons of the Thoracodorsal nerve in the ventral horn of the spinal cord as well. The sustained aberrant firing pattern might have induced over time a loss of inhibition in the cervical cord network, which is physiologically provided by the intercalated neurons of the dorsal horns, eventually provoking the spinal spreading of the movement disorder.
344
Letter to the Editor / Parkinsonism and Related Disorders 21 (2015) 343e344
Botulinum toxin A abolished almost completely the jerks. Its efficacy on peripheral movement disorders is well documented while the exact mechanism of its action on spinal abnormal movements is not completely understood as yet. This may partially be explained by the fact that botulinum toxin A can raise the firing threshold of the motor neurons through a retrograde transport and transneuronal effect, as demonstrated in animal models [5].
Conflicts of interest Nothing to report. All authors approved the final version of the manuscript.
References [1] Van Rooijen DE, Geraedts EJ, Marinus J, Jankovic J, Van Hilten JJ. Peripheral trauma and movement disorders: a systematic review of reported cases. J Neurol Neurosurg Psychiatry 2011;82:892e8. [2] Caviness JN, Gabellini A, Kneebone CS, Thompson PD, Lees AJ, Marsden CD. Unusual focal dyskinesias: the ears, the shoulders, the back, the abdomen. Mov Disord 1994;9(5):531e8. [3] Chung SJ, Lee E, Lee MC. Myoclonus of the latissimus dorsi muscle after thoracotomy. Mov Disord 2008;23(13):1949e50. [4] Flor H. Phantom-limb pain: characteristics, causes, and treatment. Lancet Neurol 2002;1:182e9. [5] Moreno-Lopez B, Pastor AM, de la Cruz RR, Delgado-Garcia JM. Dose-dependent, central effects of botulinum neurotoxin type A: a pilot study in the alert behaving cat. Neurology 1997;48:456e64.
Marco Belluzzo*, Giulia Mazzon, Mauro Catalan University of Trieste, Neurologic Clinic, Azienda OspedalieroUniversitaria Ospedali Riuniti, Trieste, Italy
Financial disclosures Nothing to report. All authors approved the final version of the manuscript.
Authors roles MB and GM collected the data and drew the first draft of the manuscript; MC critically reviewed and decided the final format of the manuscript.
*
Corresponding author. Neurological Clinic, Department of Medical, Surgical and Health Sciences, Azienda OspedalieroUniversitaria Ospedali Riuniti, Strada di Fiume, 447, Trieste 34100, Italy. Tel.: þ39 0403994568; fax: þ39 0403994284. E-mail address: [email protected] (M. Belluzzo). 4 November 2014
Contents lists available at ScienceDirect
Parkinsonism and Related Disorders journal homepage: www.elsevier.com/locate/parkreldis
Letter to the Editor
Involuntary shoulder jerks after iatrogenic Thoraco-dorsal nerve injury Keywords: Peripheral induced movement disorders Latissimus dorsi Botulinum toxin Shoulder dyskinesia
Peripherally induced movement disorders (PIMDs) represent a rare and so far poorly understood entity. PIMDs encompass a broad spectrum of clinical phenotypes, which includes dystonia, myoclonus, tremor and other hyperkinetic disorders, sometimes combined in a complex mixture of movement features difficult to characterize [1,2]. Here we describe a patient who developed involuntary jerks involving the shoulder girdle 24 years after an iatrogenic nerve traumatism. A 65 year-old lady suffered from right breast carcinoma at the age of 41, for which she underwent radical mastectomy followed by an unsuccessful surgical procedure of breast reconstruction with a pedicled myocutaneous right Latissimus Dorsi (LD) flap. Neither chemotherapy nor radiotherapy were performed. The patient has been regularly followed up without evidence of disease relapse so far. Twenty-four years later she subtly developed an irregular, low amplitude, involuntary twitching of her transposed right LD muscle. No triggers could induce or relieve the movements, which also persisted during sleep. Five months later her condition worsened. The abnormal movements spread to part of the shoulder girdle muscles of the same side, causing a significant impairment of arm utilization in daily-life activities. At the time of presentation to our department, the neurological examination showed continuous, irregular, high amplitude movements of retropulsion, abduction, elevation of the right shoulder girdle and arm flexion, sometimes with a circular component (Video 1, Segment 1). Proximal active movements of the arm could momentarily reduce the amplitude of the muscular jerks, while distal upper extremity tasks had no effect on the movements. During sleep, twitching confined exclusively to the LD. Neurological examination was otherwise unremarkable. Supplementary video related to this article can be found at http://dx.doi.org/10.1016/j.parkreldis.2015.01.003. Blood tests, head computed tomography scan and cervical magnetic resonance imaging were negative. In particular, there was no evidence of disk herniation, nor neuroforaminal stenosis at C5-8 levels on the right side. Needle electromyography (EMG) showed the presence of irregular polymorphic bursts at rest on right LD, Pectoralis Major, Deltoid and Trapezius muscles. Bursts lasted 100e800 ms, with a frequency comprised between 0.5 and 5 Hz. Needle EMG analysis of voluntary activity showed a mild to moderate degree of reduction in the recruitment of motor units in the LD http://dx.doi.org/10.1016/j.parkreldis.2015.01.003 1353-8020/© 2015 Elsevier Ltd. All rights reserved.
muscle, with an increase in amplitude and duration of potentials. On the other hand, a full interference pattern was recorded from all other muscles. Standard electroencephalography (EEG) was normal. EEG-EMG polygraphy revealed that LD was always the first firing muscle. In most circumstances the activation pattern proceeded then to Deltoid and to Trapezius. The delay between LD and Deltoid firing was comprised between 120 and 130 ms, while the delay between Deltoid and Trapezius activation ranged from 20 to 30 ms. Initially hypothesizing a spinal-originating diskyinesia, the patient was started on Clonazepam up to 6 mg/day. This drug produced a significant reduction on the amplitude and frequency of the jerks (Video 1, Segment 2). However, LD movements were not substantially affected. Owing to the suspicion of a peripheral trigger for the involuntary movements, we decided to inject that muscle with 300 units of botulinum toxin type A. Jerks did not improve. Three months later, we again administrated a total of 400 units to the muscle, with almost complete resolution of the jerks in two weeks' time (Video 1, Segment 3). This effect vanished about three months later, but was readily resumed after a further botulinum toxin injection. In this patient a hyperkinetic movement disorder developed 24 years after a surgical intervention of mastectomy and LD flap, during which it is likely that the right Thoracodorsal nerve sustained a partial injury, since we had EMG evidence of isolated chronic reinnervation on LD muscle. Absence of cervical MRI lesions and the pattern of jerks spreading on EMG poligraphy represent additional proofs in favor of a peripheral generator for the abnormal movements. The interval between peripheral injury and PIMDs onset is usually less than one year, but longer latencies have been sporadically reported [1]. The pathogenic mechanisms underlying the generation of movement disorders after peripheral nerve lesions are debated. Injury of the peripheral nerve may lead to spontaneous electrical activities of intramuscular nerve fibers and entryereentry circuits [3]. Successively spinal and maybe supraspinal remodeling ensues. A good example for this is probably represented by the so-called “jumpy stump” [4]. Indeed, in the case of partly amputated limbs, the injured peripheral nerve produces abnormal sensory inputs, which are responsible for a reorganization in the spinal circuitry. The final result of the process is an increase in motor neuron excitability. In our case we hypothesize the state of abnormal excitability was not confined to intramuscular nerve fibers, but involved motor neurons of the Thoracodorsal nerve in the ventral horn of the spinal cord as well. The sustained aberrant firing pattern might have induced over time a loss of inhibition in the cervical cord network, which is physiologically provided by the intercalated neurons of the dorsal horns, eventually provoking the spinal spreading of the movement disorder.
344
Letter to the Editor / Parkinsonism and Related Disorders 21 (2015) 343e344
Botulinum toxin A abolished almost completely the jerks. Its efficacy on peripheral movement disorders is well documented while the exact mechanism of its action on spinal abnormal movements is not completely understood as yet. This may partially be explained by the fact that botulinum toxin A can raise the firing threshold of the motor neurons through a retrograde transport and transneuronal effect, as demonstrated in animal models [5].
Conflicts of interest Nothing to report. All authors approved the final version of the manuscript.
References [1] Van Rooijen DE, Geraedts EJ, Marinus J, Jankovic J, Van Hilten JJ. Peripheral trauma and movement disorders: a systematic review of reported cases. J Neurol Neurosurg Psychiatry 2011;82:892e8. [2] Caviness JN, Gabellini A, Kneebone CS, Thompson PD, Lees AJ, Marsden CD. Unusual focal dyskinesias: the ears, the shoulders, the back, the abdomen. Mov Disord 1994;9(5):531e8. [3] Chung SJ, Lee E, Lee MC. Myoclonus of the latissimus dorsi muscle after thoracotomy. Mov Disord 2008;23(13):1949e50. [4] Flor H. Phantom-limb pain: characteristics, causes, and treatment. Lancet Neurol 2002;1:182e9. [5] Moreno-Lopez B, Pastor AM, de la Cruz RR, Delgado-Garcia JM. Dose-dependent, central effects of botulinum neurotoxin type A: a pilot study in the alert behaving cat. Neurology 1997;48:456e64.
Marco Belluzzo*, Giulia Mazzon, Mauro Catalan University of Trieste, Neurologic Clinic, Azienda OspedalieroUniversitaria Ospedali Riuniti, Trieste, Italy
Financial disclosures Nothing to report. All authors approved the final version of the manuscript.
Authors roles MB and GM collected the data and drew the first draft of the manuscript; MC critically reviewed and decided the final format of the manuscript.
*
Corresponding author. Neurological Clinic, Department of Medical, Surgical and Health Sciences, Azienda OspedalieroUniversitaria Ospedali Riuniti, Strada di Fiume, 447, Trieste 34100, Italy. Tel.: þ39 0403994568; fax: þ39 0403994284. E-mail address: [email protected] (M. Belluzzo). 4 November 2014
