- Email: [email protected]
Magnetic resonance imaging in congenital facial palsy
Brain & Development 30 (2008) 206–210 www.elsevier.com/locate/braindev
Case report
Magnetic resonance imaging in congenital facial palsy Masayuki Sasaki
a,*
, Yoshihiko Imamura a, Noriko Sato
b
a
b
Department of Child Neurology, National Center Hospital for Mental, Nervous and Muscular Disorders, National Center of Neurology and Psychiatry (NCNP), Kodaira 187-8551, Japan Department of Radiology, National Center Hospital for Mental, Nervous and Muscular Disorders, NCNP, Japan Received 6 May 2007; received in revised form 16 July 2007; accepted 29 July 2007
Abstract We report magnetic resonance (MR) findings in a patient with congenital unilateral facial palsy and a patient with atypical Moebius syndrome. MR imaging showed a complete deficiency of right facial nerve in the patient with congenital unilateral facial palsy and bilateral, thin proximal facial nerves in the Moebius syndrome patient. Three-dimensional constructive interference in steady state (3D-CISS) MR imaging, especially reconstructions perpendicular to the bilateral internal auditory channel, was very useful when diagnosing patients with facial palsy due to the associated facial nerve abnormalities. 2007 Elsevier B.V. All rights reserved. Keywords: Facial nerve; Moebius syndrome; 3D-CISS; Diagnosis
1. Introduction Congenital facial palsy is not uncommon in children. The most frequent cause of unilateral congenital facial palsy is birth injury [1]. Pressure on the temporal bone during birth can induce transient facial nerve dysfunction. Usually this injury recovers completely within several weeks. However, congenital unilateral facial nerve palsy without birth injury is rare, and usually of unknown etiology. Conventional neuroimaging does not contribute to understanding the pathogenic mechanism of this condition [2], except in the case of a large pontine lesion [3]. In contrast, congenital bilateral facial nerve palsy is usually accompanied by other congenital disorders, such as Moebius syndrome or Goldenher syndrome. Recently, congenital facial nerve absence was reported in some patients with Moebius syndrome by using three-dimensional constructive interference in steady state (3D-CISS) magnetic resonance imaging *
Corresponding author. Tel.: +81 42 341 2711; fax: +81 42 344 6745. E-mail address: [email protected] (M. Sasaki). 0387-7604/$ - see front matter 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.braindev.2007.07.014
(MRI) sequence [4,5]. We applied this method to a patient with isolated unilateral congenital facial nerve palsy and an atypical patient with Moebius syndrome, and obtained important diagnostic evidence in both patients. 2. Case reports 2.1. Patient 1 This 12-month-old boy was born to healthy and unrelated parents after an uneventful delivery at full term, not involving forceps. Right facial palsy was noticed immediately right after birth by the laterality in his crying face. He was completely healthy except for the right facial paralysis, which did not recover. He was referred to our hospital for the right facial palsy. At that time, he spoke a few words and walked with support. Motor and mental development was within normal limits, and there were no abnormal neurological findings except for his right facial palsy. The right part of his face did not move at all even when crying or smiling, and there were no wrinkles on his right
M. Sasaki et al. / Brain & Development 30 (2008) 206–210
forehead when looking upward. He could close his right eye when he slept. No other cranial nerve symptoms were noted. He was diagnosed with isolated right facial nerve palsy. Neurophysiological studies showed normal results in auditory brainstem reaction (ABR), somatosensory evoked potentials (SEP), and visual evoked potentials (VEP). The blink reflex was not induced at all on the right side, but was normal on the left side. 2.2. Patient 2 [6] This 9-month-old girl was born to healthy and unrelated parents after an uneventful delivery at full term. She did not cry at birth and she was diagnosed with mild neonatal asphyxia. She had difficulty with swallowing and needed tube feeding. Her clinical course was followed in a hospital neonatal intensive care unit. She showed delayed motor development, repeated aspiration pneumonia, and showed chronic hypoxia necessitating oxygen inhalation. Movements in her extremities were extremely weak and infrequent. She was suspected of having congenital myopathy
207
based on the severe motor delay and lack of facial expression. She was referred to our hospital for motor retardation and swallowing difficulty. She could not move her face, tongue, or swallowing muscles. She had facial and glossopharyngeal nerve palsy, with no head control. Despite the absence of abducens nerve palsy, she was tentatively diagnosed as having atypical Moebius syndrome. She underwent tracheostomy because of the repeated aspiration pneumonia and chronic hypoxia. This returned her oxygen saturation levels in the peripheral blood to normal range and activated her body movements, as well as anti-gravity movements in her extremities. The aspiration pneumonia has not recurred. 3. MR findings MRI was performed on both patients with a 1.0 T MR unit (Siemens, Harmony, Germany). Sequences included conventional T1- and T2-weighted images and 3D-CISS: TR/TE/NEX = 11.6/5.8/1, 70 flip angle, 180 · 180-mm FOV, 39.2-mm slab thickness, 256 · 224 matrix, 56 three-dimensional partitions, on
Fig. 1. 3D-constructive interference in steady state (CISS) sequences with reconstructions perpendicular to the bilateral internal auditory channel in patient 1 show complete absence of the right facial nerve. Left side is normal, indicating facial nerve (a), vestibular nerve (b), and acoustic nerve (c).
208
M. Sasaki et al. / Brain & Development 30 (2008) 206–210
slab, 0.7 · 0.8-mm pixel, 0.7-mm effective section thickness: these conditions were almost the same described previously [7]. Data obtained by using 3D-CISS MRI were reconstructed in axial planes and perpendicular planes to bilateral internal auditory channels. In patient 1, conventional T1- and T2-weighted images showed no brain abnormalities. Cranial nerves were observed by 3D-CISS MRI, and the left facial nerve was seen in the internal auditory channel. However, there was no right facial nerve in the right internal auditory channel (Fig. 1). This boy was diagnosed as having congenital absence of the right facial nerve. In patient 2, conventional T1-weighted images showed a slightly hypoplastic brain stem including the pons and medulla oblongata. T2-weighted images showed high intensity areas in the tegmentum of the
pons and mid brain, and thalamus (Fig. 2). 3D-CISS MRI showed that the proximal part of the facial nerves could not be observed bilaterally probably because they were too thin (Fig. 3). Regarding glossopharyngeal nerves no useful information was obtained because of the difficulty to visualization by 3D-CISS. 4. Discussion 3D-CISS MRI results in heavily T2-weighted images and high spatial resolution, allowing thin-slice image reconstruction to reveal details of the cisternal and canalicular portions of cranial nerves [4]. When the inner ear and facial nerve are examined, three-dimensional T1 magnetization prepared rapid gradient echo (3D MP-RAGE) and 3D-CISS should be applied [5]. 3D
Fig. 2. T2-weighted images in patient 2 shows high intensity areas in the tegmentum of the brainstem including the pons and midbrain. High intensity areas are noted in the slightly atrophic thalami, too.
M. Sasaki et al. / Brain & Development 30 (2008) 206–210
209
Fig. 3. 3D-constructive interference in steady state (CISS) sequences with reconstructions perpendicular to the bilateral internal auditory channel in patient 2. The left column (a–c) is the right internal auditory channel, and the right column (d–f) is the left internal auditory channel from proximal portion to distal portion, respectively. Figure (a) and (d) are the most proximal, and figure (c) and (f) are the most distal. The center column is the axial section. These findings show proximal thinness in bilateral facial nerves. The peripheral parts of the facial nerves remain bilateral.
MP-RAGE with gadolinium contrast enhancement is very sensitive for tumors and inflammatory lesions. 3D-CISS gives high contrast for cerebrospinal fluid and shows a filling defect [5]. 3D-CISS MRI usually shows facial nerves bilaterally in the internal auditory channel with vestiblocochlear nerves. In the present study, 3D-CISS MRI indicated the aplasia of the right facial nerve in patient 1 and the proximal thinness of bilateral facial nerves in patient 2. A congenital developmental anomaly was presumed in patient 1. Ante grade destructive changes of the bilateral facial nerves were presumed to underlie the findings, probably due to a hypoxic episode in patient 2. It was difficult to prove these subtle but important facial nerve abnormalities by conventional MRI, highlighting the usefulness of 3D-CISS MRI in these patients. This method of imaging was successful previously in detecting cranial nerve abnormalities, especially in the trigeminal (V), abducens (VI), facial (VII), and acoustic nerves (VIII) [4,5,7,8]. Verzijl et al. [4] demonstrated the complete absence of bilateral facial nerves in all 6 patients with Moebius syndrome by 3D-CISS, and proposed that this disorder could be a developmental anomaly. However, our patient 2 exhibited an extremely thin proximal part of the bilateral facial nerves on 3D-CISS MRI, with the peripheral part intact, indicating an ante grade destructive process.
Moebius syndrome has a diverse etiology. The most frequently reported feature in this syndrome is brainstem hypoplasia [9,10], possibly caused by symmetric tegmental infarcts in the fetal or neonatal brainstem associated with an episode of hypoperfusion from the basilar artery [11]. The tegmentum is a watershed zone in the brainstem, with penetrating end-arterial perfusion from the paramedian and long circumferential arteries from the basilar artery. Sarnat [11] reported that Moebius syndrome was frequently accompanied by central respiratory insufficiency, central dysphasia, and other cranial neuropathies including hypoglossal nucleus, all attributable to the bilateral columnar tegmental watershed infarcts. Consequently, an ante grade destructive change would be induced in the proximal part of the facial nerve and other cranial nerves. The conventional T2-weighted images and 3D-CISS MRI in patient 2 confirmed this hypothesis. Most patients that suffer congenital unilateral facial nerve palsy due to transient injury at birth usually recover within a few months. However, in cases with congenital facial nerve aplasia like patient 1, facial nerve palsy does not recover spontaneously. Pontine lesions were previously reported in congenital facial palsy [3]. However, no neuroimaging analysis was supplied to support the facial nerve descriptions [1,2]. 3D-CISS MRI could therefore be a valuable tool for the early dif-
210
M. Sasaki et al. / Brain & Development 30 (2008) 206–210
ferentiation of congenital nerve aplasia from birth injury. Finally, in the case of delayed recovery from either unilateral or bilateral facial palsy, 3D-CISS MRI should be employed to distinguish structural facial nerve abnormalities. References [1] Shapiro NL, Cunningham MJ, Parikh SR, Eavey RD, Cheney ML. Congenital unilateral facial paralysis. Pediatrics 1996;97: 261–5. [2] Toelle SP, Boltshauser E. Long-term outcome in children with congenital unilateral facial nerve palsy. Neuropediatrics 2001;32: 130–5. [3] Jemec B, Grobbelaar AO, Harrison DH. The abnormal nucleus as a cause of congenital facial palsy. Arch Dis Child 2000;83:256–8. [4] Verzijl HT, Valk J, de Vries R, Padberg GW. Radiologic evidence for absence of the facial nerve in Moebius syndrome. Neurology 2005;64:849–55.
[5] Held P, Fellner C, Fellner F, Seitz J, Graf S, Hilbert M, et al. MRI of inner ear and facial nerve pathology using 3D MP-RAGE and 3D CISS sequences. Br J Radiol 1997;70:558–66. [6] Imamura Y, Fujikawa Y, Komaki H, Nakagawa E, Sugai K, Sato N, et al. A case of Moebius syndrome presenting with symptoms of severe infantile form of congenital muscular disorder (in Japanese). No to Hattatsu (Tokyo) 2007;39:59–62. [7] Yagi A, Sato N, Taketomi A, Nakajima T, Morita H, Koyama Y, et al. Normal cranial nerves in the cavernous sinuses: contrastenhanced three-dimensional constructive interference in the steady state MR imaging. AJNR Am J Neuroradiol 2005;26:946–50. [8] Baek SK, Chae SW, Jung HH. Congenital internal auditory canal stenosis. J Laryngol Otol 2003;117:784–7. [9] Pedraza S, Gamez J, Rovira A, Zamora A, Grive E, Raguer N, et al. MRI findings in Moebius syndrome: correlation with clinical features. Neurology 2000;55:1058–60. [10] Ouanounou S, Saigal G, Birchansky S. Moebius syndrome. AJNR Am J Neuroradiol 2005;26:430–2. [11] Sarnat HB. Watershed infarcts in the fetal and neonatal brainstem. An aetiology of central hypoventilation, dysphasia, Moebius syndrome and micrognathia. Eur J Paediatr Neurol 2004;8:71–87.
Case report
Magnetic resonance imaging in congenital facial palsy Masayuki Sasaki
a,*
, Yoshihiko Imamura a, Noriko Sato
b
a
b
Department of Child Neurology, National Center Hospital for Mental, Nervous and Muscular Disorders, National Center of Neurology and Psychiatry (NCNP), Kodaira 187-8551, Japan Department of Radiology, National Center Hospital for Mental, Nervous and Muscular Disorders, NCNP, Japan Received 6 May 2007; received in revised form 16 July 2007; accepted 29 July 2007
Abstract We report magnetic resonance (MR) findings in a patient with congenital unilateral facial palsy and a patient with atypical Moebius syndrome. MR imaging showed a complete deficiency of right facial nerve in the patient with congenital unilateral facial palsy and bilateral, thin proximal facial nerves in the Moebius syndrome patient. Three-dimensional constructive interference in steady state (3D-CISS) MR imaging, especially reconstructions perpendicular to the bilateral internal auditory channel, was very useful when diagnosing patients with facial palsy due to the associated facial nerve abnormalities. 2007 Elsevier B.V. All rights reserved. Keywords: Facial nerve; Moebius syndrome; 3D-CISS; Diagnosis
1. Introduction Congenital facial palsy is not uncommon in children. The most frequent cause of unilateral congenital facial palsy is birth injury [1]. Pressure on the temporal bone during birth can induce transient facial nerve dysfunction. Usually this injury recovers completely within several weeks. However, congenital unilateral facial nerve palsy without birth injury is rare, and usually of unknown etiology. Conventional neuroimaging does not contribute to understanding the pathogenic mechanism of this condition [2], except in the case of a large pontine lesion [3]. In contrast, congenital bilateral facial nerve palsy is usually accompanied by other congenital disorders, such as Moebius syndrome or Goldenher syndrome. Recently, congenital facial nerve absence was reported in some patients with Moebius syndrome by using three-dimensional constructive interference in steady state (3D-CISS) magnetic resonance imaging *
Corresponding author. Tel.: +81 42 341 2711; fax: +81 42 344 6745. E-mail address: [email protected] (M. Sasaki). 0387-7604/$ - see front matter 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.braindev.2007.07.014
(MRI) sequence [4,5]. We applied this method to a patient with isolated unilateral congenital facial nerve palsy and an atypical patient with Moebius syndrome, and obtained important diagnostic evidence in both patients. 2. Case reports 2.1. Patient 1 This 12-month-old boy was born to healthy and unrelated parents after an uneventful delivery at full term, not involving forceps. Right facial palsy was noticed immediately right after birth by the laterality in his crying face. He was completely healthy except for the right facial paralysis, which did not recover. He was referred to our hospital for the right facial palsy. At that time, he spoke a few words and walked with support. Motor and mental development was within normal limits, and there were no abnormal neurological findings except for his right facial palsy. The right part of his face did not move at all even when crying or smiling, and there were no wrinkles on his right
M. Sasaki et al. / Brain & Development 30 (2008) 206–210
forehead when looking upward. He could close his right eye when he slept. No other cranial nerve symptoms were noted. He was diagnosed with isolated right facial nerve palsy. Neurophysiological studies showed normal results in auditory brainstem reaction (ABR), somatosensory evoked potentials (SEP), and visual evoked potentials (VEP). The blink reflex was not induced at all on the right side, but was normal on the left side. 2.2. Patient 2 [6] This 9-month-old girl was born to healthy and unrelated parents after an uneventful delivery at full term. She did not cry at birth and she was diagnosed with mild neonatal asphyxia. She had difficulty with swallowing and needed tube feeding. Her clinical course was followed in a hospital neonatal intensive care unit. She showed delayed motor development, repeated aspiration pneumonia, and showed chronic hypoxia necessitating oxygen inhalation. Movements in her extremities were extremely weak and infrequent. She was suspected of having congenital myopathy
207
based on the severe motor delay and lack of facial expression. She was referred to our hospital for motor retardation and swallowing difficulty. She could not move her face, tongue, or swallowing muscles. She had facial and glossopharyngeal nerve palsy, with no head control. Despite the absence of abducens nerve palsy, she was tentatively diagnosed as having atypical Moebius syndrome. She underwent tracheostomy because of the repeated aspiration pneumonia and chronic hypoxia. This returned her oxygen saturation levels in the peripheral blood to normal range and activated her body movements, as well as anti-gravity movements in her extremities. The aspiration pneumonia has not recurred. 3. MR findings MRI was performed on both patients with a 1.0 T MR unit (Siemens, Harmony, Germany). Sequences included conventional T1- and T2-weighted images and 3D-CISS: TR/TE/NEX = 11.6/5.8/1, 70 flip angle, 180 · 180-mm FOV, 39.2-mm slab thickness, 256 · 224 matrix, 56 three-dimensional partitions, on
Fig. 1. 3D-constructive interference in steady state (CISS) sequences with reconstructions perpendicular to the bilateral internal auditory channel in patient 1 show complete absence of the right facial nerve. Left side is normal, indicating facial nerve (a), vestibular nerve (b), and acoustic nerve (c).
208
M. Sasaki et al. / Brain & Development 30 (2008) 206–210
slab, 0.7 · 0.8-mm pixel, 0.7-mm effective section thickness: these conditions were almost the same described previously [7]. Data obtained by using 3D-CISS MRI were reconstructed in axial planes and perpendicular planes to bilateral internal auditory channels. In patient 1, conventional T1- and T2-weighted images showed no brain abnormalities. Cranial nerves were observed by 3D-CISS MRI, and the left facial nerve was seen in the internal auditory channel. However, there was no right facial nerve in the right internal auditory channel (Fig. 1). This boy was diagnosed as having congenital absence of the right facial nerve. In patient 2, conventional T1-weighted images showed a slightly hypoplastic brain stem including the pons and medulla oblongata. T2-weighted images showed high intensity areas in the tegmentum of the
pons and mid brain, and thalamus (Fig. 2). 3D-CISS MRI showed that the proximal part of the facial nerves could not be observed bilaterally probably because they were too thin (Fig. 3). Regarding glossopharyngeal nerves no useful information was obtained because of the difficulty to visualization by 3D-CISS. 4. Discussion 3D-CISS MRI results in heavily T2-weighted images and high spatial resolution, allowing thin-slice image reconstruction to reveal details of the cisternal and canalicular portions of cranial nerves [4]. When the inner ear and facial nerve are examined, three-dimensional T1 magnetization prepared rapid gradient echo (3D MP-RAGE) and 3D-CISS should be applied [5]. 3D
Fig. 2. T2-weighted images in patient 2 shows high intensity areas in the tegmentum of the brainstem including the pons and midbrain. High intensity areas are noted in the slightly atrophic thalami, too.
M. Sasaki et al. / Brain & Development 30 (2008) 206–210
209
Fig. 3. 3D-constructive interference in steady state (CISS) sequences with reconstructions perpendicular to the bilateral internal auditory channel in patient 2. The left column (a–c) is the right internal auditory channel, and the right column (d–f) is the left internal auditory channel from proximal portion to distal portion, respectively. Figure (a) and (d) are the most proximal, and figure (c) and (f) are the most distal. The center column is the axial section. These findings show proximal thinness in bilateral facial nerves. The peripheral parts of the facial nerves remain bilateral.
MP-RAGE with gadolinium contrast enhancement is very sensitive for tumors and inflammatory lesions. 3D-CISS gives high contrast for cerebrospinal fluid and shows a filling defect [5]. 3D-CISS MRI usually shows facial nerves bilaterally in the internal auditory channel with vestiblocochlear nerves. In the present study, 3D-CISS MRI indicated the aplasia of the right facial nerve in patient 1 and the proximal thinness of bilateral facial nerves in patient 2. A congenital developmental anomaly was presumed in patient 1. Ante grade destructive changes of the bilateral facial nerves were presumed to underlie the findings, probably due to a hypoxic episode in patient 2. It was difficult to prove these subtle but important facial nerve abnormalities by conventional MRI, highlighting the usefulness of 3D-CISS MRI in these patients. This method of imaging was successful previously in detecting cranial nerve abnormalities, especially in the trigeminal (V), abducens (VI), facial (VII), and acoustic nerves (VIII) [4,5,7,8]. Verzijl et al. [4] demonstrated the complete absence of bilateral facial nerves in all 6 patients with Moebius syndrome by 3D-CISS, and proposed that this disorder could be a developmental anomaly. However, our patient 2 exhibited an extremely thin proximal part of the bilateral facial nerves on 3D-CISS MRI, with the peripheral part intact, indicating an ante grade destructive process.
Moebius syndrome has a diverse etiology. The most frequently reported feature in this syndrome is brainstem hypoplasia [9,10], possibly caused by symmetric tegmental infarcts in the fetal or neonatal brainstem associated with an episode of hypoperfusion from the basilar artery [11]. The tegmentum is a watershed zone in the brainstem, with penetrating end-arterial perfusion from the paramedian and long circumferential arteries from the basilar artery. Sarnat [11] reported that Moebius syndrome was frequently accompanied by central respiratory insufficiency, central dysphasia, and other cranial neuropathies including hypoglossal nucleus, all attributable to the bilateral columnar tegmental watershed infarcts. Consequently, an ante grade destructive change would be induced in the proximal part of the facial nerve and other cranial nerves. The conventional T2-weighted images and 3D-CISS MRI in patient 2 confirmed this hypothesis. Most patients that suffer congenital unilateral facial nerve palsy due to transient injury at birth usually recover within a few months. However, in cases with congenital facial nerve aplasia like patient 1, facial nerve palsy does not recover spontaneously. Pontine lesions were previously reported in congenital facial palsy [3]. However, no neuroimaging analysis was supplied to support the facial nerve descriptions [1,2]. 3D-CISS MRI could therefore be a valuable tool for the early dif-
210
M. Sasaki et al. / Brain & Development 30 (2008) 206–210
ferentiation of congenital nerve aplasia from birth injury. Finally, in the case of delayed recovery from either unilateral or bilateral facial palsy, 3D-CISS MRI should be employed to distinguish structural facial nerve abnormalities. References [1] Shapiro NL, Cunningham MJ, Parikh SR, Eavey RD, Cheney ML. Congenital unilateral facial paralysis. Pediatrics 1996;97: 261–5. [2] Toelle SP, Boltshauser E. Long-term outcome in children with congenital unilateral facial nerve palsy. Neuropediatrics 2001;32: 130–5. [3] Jemec B, Grobbelaar AO, Harrison DH. The abnormal nucleus as a cause of congenital facial palsy. Arch Dis Child 2000;83:256–8. [4] Verzijl HT, Valk J, de Vries R, Padberg GW. Radiologic evidence for absence of the facial nerve in Moebius syndrome. Neurology 2005;64:849–55.
[5] Held P, Fellner C, Fellner F, Seitz J, Graf S, Hilbert M, et al. MRI of inner ear and facial nerve pathology using 3D MP-RAGE and 3D CISS sequences. Br J Radiol 1997;70:558–66. [6] Imamura Y, Fujikawa Y, Komaki H, Nakagawa E, Sugai K, Sato N, et al. A case of Moebius syndrome presenting with symptoms of severe infantile form of congenital muscular disorder (in Japanese). No to Hattatsu (Tokyo) 2007;39:59–62. [7] Yagi A, Sato N, Taketomi A, Nakajima T, Morita H, Koyama Y, et al. Normal cranial nerves in the cavernous sinuses: contrastenhanced three-dimensional constructive interference in the steady state MR imaging. AJNR Am J Neuroradiol 2005;26:946–50. [8] Baek SK, Chae SW, Jung HH. Congenital internal auditory canal stenosis. J Laryngol Otol 2003;117:784–7. [9] Pedraza S, Gamez J, Rovira A, Zamora A, Grive E, Raguer N, et al. MRI findings in Moebius syndrome: correlation with clinical features. Neurology 2000;55:1058–60. [10] Ouanounou S, Saigal G, Birchansky S. Moebius syndrome. AJNR Am J Neuroradiol 2005;26:430–2. [11] Sarnat HB. Watershed infarcts in the fetal and neonatal brainstem. An aetiology of central hypoventilation, dysphasia, Moebius syndrome and micrognathia. Eur J Paediatr Neurol 2004;8:71–87.