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Neurologically acquired laryngomalacia in a pediatric patient with Moyamoya: A case report and literature review
International Journal of Pediatric Otorhinolaryngology 116 (2019) 34–37
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Case Report
Neurologically acquired laryngomalacia in a pediatric patient with Moyamoya: A case report and literature review
T
Hayley Borna,b, Andre Winelandc, Michael J. Ruttera,b,∗ a
Cincinnati Children's Hospital Medical Center, Dept. of Pediatric Otolaryngology, United States University of Cincinnati, Dept. of Otolaryngology, United States c University of Arkansas School for Medical Sciences, Department of Otolaryngology – Head & Neck Surgery, Division of Pediatric Otolaryngology, Arkansas Children's Hospital, Little Rock, AR, USA b
A R T I C LE I N FO
A B S T R A C T
Keywords: Laryngomalacia Pediatric otolaryngology Supraglottoplasty Stroke Moyamoya Acquired laryngomalacia Stridor
Acquired laryngomalacia in the pediatric population is rare, especially from a neurogenic cause. This case report describes a pediatric patient who developed laryngomalacia following a neurologic insult. A proposed physiologic pathway is reviewed. A thorough literature review was performed to identify cases of acquired laryngomalacia ascribed to a neurologic cause and are compared to this case.
1. Patient history This report reviews the case of a pediatric patient who was diagnosed with acute onset laryngomalacia following a neurologic insult related to Moyamoya disease. She was born at 38 weeks gestation and was found to have growth delay, glossoptosis, micrognathia, broad nasal root, telecanthus, cleft lip and palate, ventricular septal defect (VSD), left finger syndactyly, and bilateral fibular hypoplasia. There were no documented prenatal risk factors. Her genetics work-up revealed two genetic abnormalities: HOXD13 and AMER1 which are catalogued in the National Center for Biotechnology Information (NCBI) gene database. The paternally inherited HOXD13 mutation has been associated with syndactyly. The AMER1 gene mutation was de novo and is associated with many of her congenital abnormalities in a syndrome called osteopathia striata with cranial sclerosis (OSCS). The mutation has also been known to be associated with tracheomalacia and laryngeal webbing, neither of which had been noted in this patient prior to arrival. Unrelated to the subject at hand, her VSD closed spontaneously and her syndactyly was repaired at one year of age. She had her cleft lip and palate repaired as an infant. A tracheostomy and PEG tube placement was required at two weeks of age for respiratory failure. She was unable to be decannulated due to suprastomal collapse. She was referred to our institution at two years of age for airway management. She underwent a single stage
laryngotracheoplasty (LTP) with anterior costal cartilage graft in November of 2016. Laryngomalacia was not seen on either awake flexible laryngoscopy or rigid bronchoscopy pre-operatively. Fig. 1. The patient's post-operative recovery was uneventful and she was discharged on post-operative day (POD) 9 after undergoing a follow-up microlaryngoscopy and bronchoscopy (MLB) that did not reveal any findings of laryngomalacia. Specifically, she did not have stridor or retractions during her post-operative course. She was seen again a week later for a repeat MLB that again revealed no signs or symptoms of laryngomalacia. She then returned to her home state. Six days later she developed left extremity weakness. A head CT revealed right posterior parietal hypodensity consistent with a cerebrovascular accident (CVA). Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the brain showed an acute right posterior and parietal stroke along with bilateral carotid artery stenosis, with a 100% occlusion on the left, and a 90% stenosis on the right. Concurrent with her new neurologic symptoms, the patient developed severe stridor and retractions, prompting a MLB. This revealed severe laryngomalacia and possible anterior graft prolapse necessitating transfer back to our institute for further management. Upon arrival, she was stable on room air and her extremity weakness had resolved. Further airway intervention was deferred due to her neurologic and vascular issues. The patient was discharged locally for outpatient pre-operative work-up. She was diagnosed with Moyamoya disease.
∗ Corresponding author. Division of Pediatric Otolaryngology–Head and Neck Surgery, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 2018, Cincinnati, OH 45229-3039, United States. E-mail address: [email protected] (M.J. Rutter).
https://doi.org/10.1016/j.ijporl.2018.10.001 Received 9 July 2018; Received in revised form 7 September 2018; Accepted 1 October 2018 Available online 04 October 2018 0165-5876/ © 2018 Elsevier B.V. All rights reserved.
International Journal of Pediatric Otorhinolaryngology 116 (2019) 34–37
H. Born et al.
Fig. 1. Patient's pre-LTP, pre-insult microlaryngoscopy on expiration (1a) and inspiration (1b).
Fig. 2. Patient's post-LTP post-insult microlaryngoscopy on expiration (2a) and inspiration (2b).
used a pulse oximeter at home without significant desaturations. Given her improved clinical status, the patient was observed until her next airway evaluation a few months later. As her stridor during sleep had become slightly worse with time, and as her laryngomalacia was still evident (Fig. 4), a revision supraglottoplasty was performed 18 months after the initial LTP. This eliminated the nocturnal stridor, and 5 months later symptoms had not returned.
During her work-up, however, she developed recurrent respiratory issues. An MLB revealed severe laryngomalacia with a stable anterior graft and no evidence of glottic, subglottic or tracheal stenosis. Fig. 2 Angiography displayed new infarcts and severe segmental stenosis of intracranial right internal carotid with reconstitution by retrograde flow of the left ophthalmic artery from the left external carotid artery. Multifocal infarcts in watershed areas of brain were thought to be likely due to decreased cerebral flow due to her underlying bilateral internal carotid artery stenosis. Aspirin was continued and neurosurgery began planning for reperfusion procedure. The patient also underwent oxygen titration study (on 5L simple mask) due to observed desaturations that demonstrated a desaturation index of 1.0 (lowest recorded oxygen saturation was 74%, 0.1% of the entire 8 hour study with oxygen saturations < 88%, mean SpO2 was 99.9, no bradycardia.) Given these results, the patient was placed on 5L of simple mask oxygen until more definitive surgical correction could be done. She underwent staged carotid artery repair via right craniotomy for cerebral bypass with pial synangiosis with parietal superficial temporal artery anastomosis and second vessel revascularization via dural inversion using the middle meningeal artery. A month later she underwent left craniotomy with pial synagiosis with parietal superficial artery anastomosis and revascularization using the middle meningeal artery. After recovering from her re-vascularization procedures, she underwent a routine but conservative supraglottoplasty 4 months following the LTP, and was discharged on POD 1 with a marked reduction in symptoms. She returned for airway evaluation 4 months afterward, at which time she was no longer requiring oxygen. She had persistent inspiratory stridor with sleep and intermittent, self-resolving desaturations while sleeping. She was taking all nutrition orally. Her airway evaluation revealed a widely patent airway, but with some enlarged arytenoids, shortened aryepiglottic folds, and mild laryngomalacia thought to be exacerbated by the anesthesia. Fig. 3 No sleep study or oxygen saturation studies were performed, however her parents had
2. Discussion 2.1. Moyamoya Moyamoya refers to the progressive stenosis of the intracranial internal carotid arteries and their proximal branches, a bilateral finding [1]. It is not caused by atherosclerosis or inflammation but rather vessel hyperplasia and thrombosis. This condition predisposes patient to strokes and transient ischemic events. It has been shown to have a likely genetic basis though specific pathways have not been identified therefore it is unknown whether our patient's genetic abnormalities predisposed her to the condition. Her only family history was a paternal grandmother who had a stroke in her 40s. When identified in patients with well-recognized associated conditions such as prior head and neck radiotherapy, sickle cell anemia, trisomy 21, or neurofibromatosis type 1, a patient is said to have Moyamoya Syndrome. When a clear disease association is not present, as in our patient, the patient has Moyamoya Disease. The carotid stenosis in Moyamoya is bilateral by definition but may be asymmetric. Our patient had a complete occlusion on the left and a 90% occlusion of the right carotid. Ischemic events resulting from this stenosis can be spontaneous or associated with exertion (including crying or hyperventilation) or anesthesia induction.
35
International Journal of Pediatric Otorhinolaryngology 116 (2019) 34–37
H. Born et al.
Fig. 3. Patient's post-LTP, post-insult, 3-months-post-supraglottoplasty microlaryngoscopy on expiration (3a) and inspiration (3b).
age as defined by the American Academy of pediatrics [4]. Congenital pediatric neurogenic laryngomalacia has been described in patients with cerebral palsy (CP) [5]. These children, initially diagnosed with laryngomalacia, have been found to have CP associated laryngeal dystonia causing stridor. Additionally patients with Chiari malformation or brainstem compression from intracranial edema can have stridor, usually the result of vocal cord paresis. Petersson et al. described such cases of laryngomalacia causing stridor in pediatric Chiari patients. The malacic symptoms resolved with relief of their brainstem compression [6]. Most other references to acquired neurologic laryngomalacia are in case series for treatment algorithms. In 1988, Peron proposed a disruption of normal neuromuscular tone and subsequent redundant arytenoid tissue as being of central nervous system origin in seven patients, ages 1.5–20 years, with acquired laryngomalacia after neurologic insult [7]. He focused on treatment algorithms similar to laryngomalacia presenting with redundant arytenoid tissue. Archer et al. describe a case of an 11-year-old boy who had complete supraglottic collapse and obstruction following a midpontine infarction [8]. This patient was successfully treated with epiglottoplasty. Woo presented eight cases of acquired epiglottic prolapse in patients aged 19–68 (two were 21 or younger), 6 of which followed head injury or coma [9]. Many patients had persistent laryngomalacia despite resolution of their neurologic symptoms. Epiglottectomy was performed successfully in all cases. Finally, a 1995 paper by Wiggs et al. describes five patients who displayed acquired laryngomalacia [10]. Though the age of patients in this paper ranged from age 20–75 years of age, one was under 21 years old. Three of the reported patient's presentations followed traumatic brain injury, one had a diagnosis of Parkinson's disease and one had amyotrophic lateral sclerosis. Those patients who had resolution of their neurologic symptoms were also found to have resolution of their laryngomalacia.
2.2. Neurologic pathway for laryngomalacia In 1984, Belmont and Grundfast demonstrated, through cadaveric dissections, that muscular actions of the hyoglossus, digastric, palatopharyngeus, palatoglossus, and some intrinsic laryngeal muscles provide support and dilate the supraglottic larynx [2]. It follows, then, that any neurologic insult that disrupts innervation of these muscles may result in laryngomalacia. While examining possible etiologies for congenital laryngomalacia, Thompson discusses integration of complex neurologic pathways as a possible cause for decreased laryngeal tone [3]. The same principals may explain loss of tone in acquired neurologic insults disrupting these pathways. Complex integration of afferent and efferent signals including peripheral sensory afferent reflexes, brainstem functions, and motor efferent responses are involved in tone and function of the larynx and disruption of this pathway likely contributes to both congenital and acquired malacia. The laryngeal adductor reflex is the primary pathway for such signals. Mechanoreceoptors and chemoreceptors of the superior laryngeal nerve are stimulated in the aryepiglottic fold. Afferent signals are transferred to brainstem nuclei and subsequent integration between the nucleus tractus solitaries and nucleus ambiguous occurs. Finally efferent responses travel via the vagus nerve resulting in an involuntary adduction of vocal folds and triggers swallow. This pathway, along with tonic innervation of the laryngeal muscles and other less understood pathways likely combine to counter laryngomalacia. It is likely that ischemic injury to one or more of these pathways within the brain resulted in our patient's laryngomalacia. 2.3. Examples in the literature While neurological variant laryngomalacia is well recognized, this is usually congenital in nature, and acquired cases are extremely rare. A thorough search of the literature returned several publications dealing with neurogenic laryngomalacia in pediatric patients, up to 21 years of
Fig. 4. Patient's post-LTP, post-insult, 6 months-post-supraglottoplasty microlaryngoscopy on expiration (4a) and inspiration (4b). 36
International Journal of Pediatric Otorhinolaryngology 116 (2019) 34–37
H. Born et al.
young child. Both symptomatically and based on laryngoscopy pre-CVA and post-CVA, this is perhaps the best example of acquired neurological laryngomalacia yet documented, and lends weight to the theory that the etiology of laryngomalacia has a neurological basis.
2.4. The unique aspects of this case While the etiology of laryngomalacia is still debated, a neurological basis of disease is still a leading contender. This case is unique in that this child had several laryngoscopies, both awake and anesthetized, that showed no evidence of laryngomalacia and had no symptoms consistent with laryngomalacia prior to a CVA. Following the CVA, she was immediately severely stridulous with retractions and a nocturnal oxygen need, and with severe laryngomalacia being noted on laryngoscopy. Her symptoms greatly improved following a conservative supraglottoplasty, and completely resolved following revision supraglottoplasty. While it could be debated that her laryngomalacia was masked by the pre-operative presence of a tracheotomy tube [11], there was a 3 week period post decannulation, and prior to the CVA, that she was both asymptomatic, and without evidence of laryngomalacia on laryngoscopy. Her airway reconstructive surgery, moreover, was to address suprastomal collapse, not any laryngeal cause of obstruction. The anterior graft was placed into an anterior cricoid split, but did not involve the thyroid cartilage There is, therefore, no plausible reason for the LTP to have influenced the supraglottic larynx.
Conflicts of interest There are no conflicts of interest for any of the above authors as defined by the International Journal of Pediatric Otorhinolaryngology. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
3. Conclusion [11]
This report details a unique presentation of acquired laryngomalacia following a neurologic insult in the setting of Moyamoya disease in a
37
R.M. Scott, E.R. Smith, N. Engl. J. Med. 360 (2009) 1226–1237 2009. J.R. Belmont, K. Grundfast, Ann. Otol. Rhinol. Laryngol. 93 (1984) 430–437 1984. D.M. Thompson, Laryngoscope 117 (2007) 1–33 2007. I.F. Litt, Pediatrics 102 (1998) 249–250 1998. G. Worley, D.L. Witsell, G.F. Hulka, Laryngoscope 113 (2003) 2192–2195 2003. R.S. Petersson, N.M. Wetjen, D.M. Thompson, Ann. Otol. Rhinol. Laryngol. 120 (2011) 99–103 2011. D.L. Peron, D.B. Graffino, D.O. Zenker, Laryngoscope 98 (1988) 659–663 1988. S.M. Archer, Arch. Otolaryngol. Head Neck Surg. 118 (1992) 654–657 1992. P. Woo, Ann. Otol. Rhinol. Laryngol. 101 (1992) 314–320 1992. W.J. Wiggs Jr., L.J. DiNardo, Otolaryngology–head and neck surgery, official journal of American Academy of Otolaryngology-Head and Neck Surgery 112 (1995) 773–776 1995. M.J. Rutter, D.T. Link, J.H. Liu, et al., Laryngotracheal reconstruction and the hidden airway lesion, Laryngoscope 110 (2000) 1871–1874.
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Case Report
Neurologically acquired laryngomalacia in a pediatric patient with Moyamoya: A case report and literature review
T
Hayley Borna,b, Andre Winelandc, Michael J. Ruttera,b,∗ a
Cincinnati Children's Hospital Medical Center, Dept. of Pediatric Otolaryngology, United States University of Cincinnati, Dept. of Otolaryngology, United States c University of Arkansas School for Medical Sciences, Department of Otolaryngology – Head & Neck Surgery, Division of Pediatric Otolaryngology, Arkansas Children's Hospital, Little Rock, AR, USA b
A R T I C LE I N FO
A B S T R A C T
Keywords: Laryngomalacia Pediatric otolaryngology Supraglottoplasty Stroke Moyamoya Acquired laryngomalacia Stridor
Acquired laryngomalacia in the pediatric population is rare, especially from a neurogenic cause. This case report describes a pediatric patient who developed laryngomalacia following a neurologic insult. A proposed physiologic pathway is reviewed. A thorough literature review was performed to identify cases of acquired laryngomalacia ascribed to a neurologic cause and are compared to this case.
1. Patient history This report reviews the case of a pediatric patient who was diagnosed with acute onset laryngomalacia following a neurologic insult related to Moyamoya disease. She was born at 38 weeks gestation and was found to have growth delay, glossoptosis, micrognathia, broad nasal root, telecanthus, cleft lip and palate, ventricular septal defect (VSD), left finger syndactyly, and bilateral fibular hypoplasia. There were no documented prenatal risk factors. Her genetics work-up revealed two genetic abnormalities: HOXD13 and AMER1 which are catalogued in the National Center for Biotechnology Information (NCBI) gene database. The paternally inherited HOXD13 mutation has been associated with syndactyly. The AMER1 gene mutation was de novo and is associated with many of her congenital abnormalities in a syndrome called osteopathia striata with cranial sclerosis (OSCS). The mutation has also been known to be associated with tracheomalacia and laryngeal webbing, neither of which had been noted in this patient prior to arrival. Unrelated to the subject at hand, her VSD closed spontaneously and her syndactyly was repaired at one year of age. She had her cleft lip and palate repaired as an infant. A tracheostomy and PEG tube placement was required at two weeks of age for respiratory failure. She was unable to be decannulated due to suprastomal collapse. She was referred to our institution at two years of age for airway management. She underwent a single stage
laryngotracheoplasty (LTP) with anterior costal cartilage graft in November of 2016. Laryngomalacia was not seen on either awake flexible laryngoscopy or rigid bronchoscopy pre-operatively. Fig. 1. The patient's post-operative recovery was uneventful and she was discharged on post-operative day (POD) 9 after undergoing a follow-up microlaryngoscopy and bronchoscopy (MLB) that did not reveal any findings of laryngomalacia. Specifically, she did not have stridor or retractions during her post-operative course. She was seen again a week later for a repeat MLB that again revealed no signs or symptoms of laryngomalacia. She then returned to her home state. Six days later she developed left extremity weakness. A head CT revealed right posterior parietal hypodensity consistent with a cerebrovascular accident (CVA). Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the brain showed an acute right posterior and parietal stroke along with bilateral carotid artery stenosis, with a 100% occlusion on the left, and a 90% stenosis on the right. Concurrent with her new neurologic symptoms, the patient developed severe stridor and retractions, prompting a MLB. This revealed severe laryngomalacia and possible anterior graft prolapse necessitating transfer back to our institute for further management. Upon arrival, she was stable on room air and her extremity weakness had resolved. Further airway intervention was deferred due to her neurologic and vascular issues. The patient was discharged locally for outpatient pre-operative work-up. She was diagnosed with Moyamoya disease.
∗ Corresponding author. Division of Pediatric Otolaryngology–Head and Neck Surgery, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 2018, Cincinnati, OH 45229-3039, United States. E-mail address: [email protected] (M.J. Rutter).
https://doi.org/10.1016/j.ijporl.2018.10.001 Received 9 July 2018; Received in revised form 7 September 2018; Accepted 1 October 2018 Available online 04 October 2018 0165-5876/ © 2018 Elsevier B.V. All rights reserved.
International Journal of Pediatric Otorhinolaryngology 116 (2019) 34–37
H. Born et al.
Fig. 1. Patient's pre-LTP, pre-insult microlaryngoscopy on expiration (1a) and inspiration (1b).
Fig. 2. Patient's post-LTP post-insult microlaryngoscopy on expiration (2a) and inspiration (2b).
used a pulse oximeter at home without significant desaturations. Given her improved clinical status, the patient was observed until her next airway evaluation a few months later. As her stridor during sleep had become slightly worse with time, and as her laryngomalacia was still evident (Fig. 4), a revision supraglottoplasty was performed 18 months after the initial LTP. This eliminated the nocturnal stridor, and 5 months later symptoms had not returned.
During her work-up, however, she developed recurrent respiratory issues. An MLB revealed severe laryngomalacia with a stable anterior graft and no evidence of glottic, subglottic or tracheal stenosis. Fig. 2 Angiography displayed new infarcts and severe segmental stenosis of intracranial right internal carotid with reconstitution by retrograde flow of the left ophthalmic artery from the left external carotid artery. Multifocal infarcts in watershed areas of brain were thought to be likely due to decreased cerebral flow due to her underlying bilateral internal carotid artery stenosis. Aspirin was continued and neurosurgery began planning for reperfusion procedure. The patient also underwent oxygen titration study (on 5L simple mask) due to observed desaturations that demonstrated a desaturation index of 1.0 (lowest recorded oxygen saturation was 74%, 0.1% of the entire 8 hour study with oxygen saturations < 88%, mean SpO2 was 99.9, no bradycardia.) Given these results, the patient was placed on 5L of simple mask oxygen until more definitive surgical correction could be done. She underwent staged carotid artery repair via right craniotomy for cerebral bypass with pial synangiosis with parietal superficial temporal artery anastomosis and second vessel revascularization via dural inversion using the middle meningeal artery. A month later she underwent left craniotomy with pial synagiosis with parietal superficial artery anastomosis and revascularization using the middle meningeal artery. After recovering from her re-vascularization procedures, she underwent a routine but conservative supraglottoplasty 4 months following the LTP, and was discharged on POD 1 with a marked reduction in symptoms. She returned for airway evaluation 4 months afterward, at which time she was no longer requiring oxygen. She had persistent inspiratory stridor with sleep and intermittent, self-resolving desaturations while sleeping. She was taking all nutrition orally. Her airway evaluation revealed a widely patent airway, but with some enlarged arytenoids, shortened aryepiglottic folds, and mild laryngomalacia thought to be exacerbated by the anesthesia. Fig. 3 No sleep study or oxygen saturation studies were performed, however her parents had
2. Discussion 2.1. Moyamoya Moyamoya refers to the progressive stenosis of the intracranial internal carotid arteries and their proximal branches, a bilateral finding [1]. It is not caused by atherosclerosis or inflammation but rather vessel hyperplasia and thrombosis. This condition predisposes patient to strokes and transient ischemic events. It has been shown to have a likely genetic basis though specific pathways have not been identified therefore it is unknown whether our patient's genetic abnormalities predisposed her to the condition. Her only family history was a paternal grandmother who had a stroke in her 40s. When identified in patients with well-recognized associated conditions such as prior head and neck radiotherapy, sickle cell anemia, trisomy 21, or neurofibromatosis type 1, a patient is said to have Moyamoya Syndrome. When a clear disease association is not present, as in our patient, the patient has Moyamoya Disease. The carotid stenosis in Moyamoya is bilateral by definition but may be asymmetric. Our patient had a complete occlusion on the left and a 90% occlusion of the right carotid. Ischemic events resulting from this stenosis can be spontaneous or associated with exertion (including crying or hyperventilation) or anesthesia induction.
35
International Journal of Pediatric Otorhinolaryngology 116 (2019) 34–37
H. Born et al.
Fig. 3. Patient's post-LTP, post-insult, 3-months-post-supraglottoplasty microlaryngoscopy on expiration (3a) and inspiration (3b).
age as defined by the American Academy of pediatrics [4]. Congenital pediatric neurogenic laryngomalacia has been described in patients with cerebral palsy (CP) [5]. These children, initially diagnosed with laryngomalacia, have been found to have CP associated laryngeal dystonia causing stridor. Additionally patients with Chiari malformation or brainstem compression from intracranial edema can have stridor, usually the result of vocal cord paresis. Petersson et al. described such cases of laryngomalacia causing stridor in pediatric Chiari patients. The malacic symptoms resolved with relief of their brainstem compression [6]. Most other references to acquired neurologic laryngomalacia are in case series for treatment algorithms. In 1988, Peron proposed a disruption of normal neuromuscular tone and subsequent redundant arytenoid tissue as being of central nervous system origin in seven patients, ages 1.5–20 years, with acquired laryngomalacia after neurologic insult [7]. He focused on treatment algorithms similar to laryngomalacia presenting with redundant arytenoid tissue. Archer et al. describe a case of an 11-year-old boy who had complete supraglottic collapse and obstruction following a midpontine infarction [8]. This patient was successfully treated with epiglottoplasty. Woo presented eight cases of acquired epiglottic prolapse in patients aged 19–68 (two were 21 or younger), 6 of which followed head injury or coma [9]. Many patients had persistent laryngomalacia despite resolution of their neurologic symptoms. Epiglottectomy was performed successfully in all cases. Finally, a 1995 paper by Wiggs et al. describes five patients who displayed acquired laryngomalacia [10]. Though the age of patients in this paper ranged from age 20–75 years of age, one was under 21 years old. Three of the reported patient's presentations followed traumatic brain injury, one had a diagnosis of Parkinson's disease and one had amyotrophic lateral sclerosis. Those patients who had resolution of their neurologic symptoms were also found to have resolution of their laryngomalacia.
2.2. Neurologic pathway for laryngomalacia In 1984, Belmont and Grundfast demonstrated, through cadaveric dissections, that muscular actions of the hyoglossus, digastric, palatopharyngeus, palatoglossus, and some intrinsic laryngeal muscles provide support and dilate the supraglottic larynx [2]. It follows, then, that any neurologic insult that disrupts innervation of these muscles may result in laryngomalacia. While examining possible etiologies for congenital laryngomalacia, Thompson discusses integration of complex neurologic pathways as a possible cause for decreased laryngeal tone [3]. The same principals may explain loss of tone in acquired neurologic insults disrupting these pathways. Complex integration of afferent and efferent signals including peripheral sensory afferent reflexes, brainstem functions, and motor efferent responses are involved in tone and function of the larynx and disruption of this pathway likely contributes to both congenital and acquired malacia. The laryngeal adductor reflex is the primary pathway for such signals. Mechanoreceoptors and chemoreceptors of the superior laryngeal nerve are stimulated in the aryepiglottic fold. Afferent signals are transferred to brainstem nuclei and subsequent integration between the nucleus tractus solitaries and nucleus ambiguous occurs. Finally efferent responses travel via the vagus nerve resulting in an involuntary adduction of vocal folds and triggers swallow. This pathway, along with tonic innervation of the laryngeal muscles and other less understood pathways likely combine to counter laryngomalacia. It is likely that ischemic injury to one or more of these pathways within the brain resulted in our patient's laryngomalacia. 2.3. Examples in the literature While neurological variant laryngomalacia is well recognized, this is usually congenital in nature, and acquired cases are extremely rare. A thorough search of the literature returned several publications dealing with neurogenic laryngomalacia in pediatric patients, up to 21 years of
Fig. 4. Patient's post-LTP, post-insult, 6 months-post-supraglottoplasty microlaryngoscopy on expiration (4a) and inspiration (4b). 36
International Journal of Pediatric Otorhinolaryngology 116 (2019) 34–37
H. Born et al.
young child. Both symptomatically and based on laryngoscopy pre-CVA and post-CVA, this is perhaps the best example of acquired neurological laryngomalacia yet documented, and lends weight to the theory that the etiology of laryngomalacia has a neurological basis.
2.4. The unique aspects of this case While the etiology of laryngomalacia is still debated, a neurological basis of disease is still a leading contender. This case is unique in that this child had several laryngoscopies, both awake and anesthetized, that showed no evidence of laryngomalacia and had no symptoms consistent with laryngomalacia prior to a CVA. Following the CVA, she was immediately severely stridulous with retractions and a nocturnal oxygen need, and with severe laryngomalacia being noted on laryngoscopy. Her symptoms greatly improved following a conservative supraglottoplasty, and completely resolved following revision supraglottoplasty. While it could be debated that her laryngomalacia was masked by the pre-operative presence of a tracheotomy tube [11], there was a 3 week period post decannulation, and prior to the CVA, that she was both asymptomatic, and without evidence of laryngomalacia on laryngoscopy. Her airway reconstructive surgery, moreover, was to address suprastomal collapse, not any laryngeal cause of obstruction. The anterior graft was placed into an anterior cricoid split, but did not involve the thyroid cartilage There is, therefore, no plausible reason for the LTP to have influenced the supraglottic larynx.
Conflicts of interest There are no conflicts of interest for any of the above authors as defined by the International Journal of Pediatric Otorhinolaryngology. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
3. Conclusion [11]
This report details a unique presentation of acquired laryngomalacia following a neurologic insult in the setting of Moyamoya disease in a
37
R.M. Scott, E.R. Smith, N. Engl. J. Med. 360 (2009) 1226–1237 2009. J.R. Belmont, K. Grundfast, Ann. Otol. Rhinol. Laryngol. 93 (1984) 430–437 1984. D.M. Thompson, Laryngoscope 117 (2007) 1–33 2007. I.F. Litt, Pediatrics 102 (1998) 249–250 1998. G. Worley, D.L. Witsell, G.F. Hulka, Laryngoscope 113 (2003) 2192–2195 2003. R.S. Petersson, N.M. Wetjen, D.M. Thompson, Ann. Otol. Rhinol. Laryngol. 120 (2011) 99–103 2011. D.L. Peron, D.B. Graffino, D.O. Zenker, Laryngoscope 98 (1988) 659–663 1988. S.M. Archer, Arch. Otolaryngol. Head Neck Surg. 118 (1992) 654–657 1992. P. Woo, Ann. Otol. Rhinol. Laryngol. 101 (1992) 314–320 1992. W.J. Wiggs Jr., L.J. DiNardo, Otolaryngology–head and neck surgery, official journal of American Academy of Otolaryngology-Head and Neck Surgery 112 (1995) 773–776 1995. M.J. Rutter, D.T. Link, J.H. Liu, et al., Laryngotracheal reconstruction and the hidden airway lesion, Laryngoscope 110 (2000) 1871–1874.