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Unilateral hypoglossal nerve palsy due to neurovascular conflict in a child
Brain & Development 31 (2009) 461–464 www.elsevier.com/locate/braindev
Case report
Unilateral hypoglossal nerve palsy due to neurovascular conflict in a child Irene Toldo *, Renzo Manara, Stefano Sartori, Agnese Suppiej, Paola Drigo Department of Pediatrics, University of Padova, Via Giustiniani, 3, 35128 Padova, Italy Received 18 February 2008; received in revised form 30 March 2008; accepted 6 August 2008
Abstract A neurovascular conflict (NC) consists of a pathological contact between a vessel, generally an artery, and the root entry zone of a cranial nerve close to the brainstem. Even if NC of the V, VII and IX cranial nerve have been rarely described, to the best of our knowledge there is no report about the XII cranial nerve NC in the paediatric age. A three-year-old girl presented with right-sided tongue atrophy and fasciculation, of one-year-duration, consistent with a peripheral lesion of the right XII cranial nerve. Brain MRI and MRA documented a marked tortuosity of the vertebrobasilar arteries compressing the brainstem at the emergency of the XII cranial nerve, while the CT disclosed a concomitant osseous malformation of the cranio-cervical junction. The differential diagnosis of a peripheral unilateral cranial nerve palsy should include, even if rare in children, a neurovascular conflict. In this case a complete neuroimaging study is indicated. Ó 2008 Elsevier B.V. All rights reserved. Keywords: Neurovascular conflict; Hypoglossal nerve palsy; Unilateral; Tongue; Fasciculation; Vertebrobasilar arteries
1. Introduction A contact between a vessel, generally an artery, and the root entry zone of a cranial nerve close to the brainstem may cause a neurovascular conflict (NC). This condition is generally associated with a hyperactive cranial nerve dysfunction syndrome (neuralgia, spasm) [1]. Neurovascular conflict has been reported in adult patients affected by trigeminal or gloss pharyngeal neuralgia, hemifacial spasm or disabling positional vertigo. Other clinical syndromes related to brainstem compression, caused by anatomic variants of the vertebrobasilar arteries, comprise cerebellar dysfunction, hydrocephalus, ischemic stroke, pyramidal tract signs and lower cranial nerve dysfunction syndrome (dysphonia, dysphagia) [2].
These syndromes seem to be caused by unilateral vascular compression of a cranial nerve at the brainstem, especially at the root entry zone, which is the transition area between the peripheral and central myelin and is particularly vulnerable to continuous pulsatile pressure [3]. In paediatric patients, NC is a rare condition and only trigeminal and gloss pharyngeal neuralgias have been reported as clinical symptoms [4]. In the literature there are no reports of NC involving the hypoglossal nerve neither in adults nor in children. We present a child with unilateral hypoglossal nerve palsy and tongue fasciculation in whom a vascular contact to the XII cranial nerve is documented by magnetic resonance imaging (MRI) and MR-angiography (MRA). 2. Case report
*
Corresponding author. Tel.: +39 049 8218094; fax: +39 049 8213509. E-mail address: [email protected] (I. Toldo). 0387-7604/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.braindev.2008.08.009
A three-year-old girl presented to our clinic with right-sided tongue atrophy and fasciculation, of oneyear-duration. Her clinical history was unremarkable.
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I. Toldo et al. / Brain & Development 31 (2009) 461–464
On neurological examination a partial deficit of motility with atrophy and fasciculation of right tongue was observed (Fig. 1). Palatine veil was symmetric. She had mild sialorrhea and rhinolalia and her expressive language was appropriate to the age. Cranial nerve XI function was normal. Phoniatric and audiologic evaluation didn’t reveal any other abnormality. Brain MRI and MRA disclosed elongated and tortuous vertebral arteries with a neurovascular compres-
sion of the medulla oblongata at the level of the right corticospinal tract and the right inferior olivary nucleus with involvement of the interposed anterior olivary sulcus, i.e. the hypoglossal nerve entry zone (Fig. 2a–f). CT (computer tomography) scan with three-dimensional reconstruction showed a coexistent atlo-occipital malformation with relative stenosis of the hypoglossal foramen (Fig. 3a–b). Electromyography study of right arm and trapezium was normal. Upper limb somatosensory evoked potentials (SEPs) showed an abnormal P14 component following left median nerve stimulation. The follow-up at 1 year revealed a stable clinical picture, the child never complained dysphagia. 3. Discussion
Fig. 1. Photograph of the patient’s tongue at 3 years of age. Patient’s tongue is deviated towards right due to partial deficit of unilateral hypoglossal nerve and it is atrophic on the right side.
Brainstem compression caused by anatomic variants of the vertebrobasilar arteries has been rarely reported; so far about 20 adult cases have been described [2]. A variety of clinical syndromes have been related to pulsatile compression by ectatic vertebrobasilar arteries: cerebellar dysfunction, hydrocephalus and ischemic stroke, as well as medulla oblongata compression [2].
Fig. 2. Cerebral MRI and MRA at 3 years of age. (a–b) Axial T2 images at the level of the medulla oblongata: the vertebral arteries (signal void indicated by white arrows) are elongated and tortuous; the brainstem is compressed particularly at the level of the right corticospinal tract and the right inferior olivary nucleus with involvement of the interposed anterior olivary sulcus (root entry zone of the hypoglossal nerve). (c) Axial T1 image at the same level of (b) showing the brainstem deformity. (d–e) Sagittal T1 images showing the medulla oblongata clearly distorted and angulated. (f) MRA of the circle of Willis (MIP 3D reconstruction) showing tortuosity of the inferior part of the vertebrobasilar arteries.
I. Toldo et al. / Brain & Development 31 (2009) 461–464
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Fig. 3. CT scan with 3D reconstruction at 3 years of age. (a) Axial image at the level of the hypoglossal foramen showing a relative stenosis on the right side. (b) CT 3D reconstruction (SSS technique) disclosing a coexistent atlo-occipital malformation.
Compression of the medulla oblongata has been reported to cause pyramidal tract signs, cranial nerve dysfunction syndrome and, more rarely, even sleep-disordered breathing (central or obstructive apnoea) [2]. MRI combined with MRA is the best modality in the diagnosis of NC by showing the course of the artery and the precise anatomic relationship between the vascular anomaly and the compressed medulla oblongata [2]. The cranial nerve dysfunction syndrome occurs because the nerve is particularly vulnerable to continuous pulsatile pressure at the root entry zone, which is the transition area between the peripheral and central myelin in the brainstem. The cranial nerves usually involved in NC are V, VII, VIII, IX and X [2–4,5]. There are few case reports of NC involving the VI and XI cranial nerves [6,7]. To the best of our knowledge, there are no reports about isolated NC of the XII cranial nerve neither in adults nor in children. Shiozawa reported a case of hypoglossal nerve palsy due to venous compression of the hypoglossal nerve by an enlarged emissary vein inside the hypoglossal canal [8]. In this case the XII nerve compression was determined by a space occupying venous lesion so it cannot be strictly considered as a NC, because the enlarged vein does not apply a pulsatile pression on the nerve. In fact strict criteria for neurovascular conflict state that the offending vessel must be an artery, the site of contact must be the root entry zone, the vessel must cross the nerve perpendicularly, and the nerve must be deviated or indented by the vessel or compressed or encased between two or more adjacent vessels in the appropriate clinical setting [5]. As well as a vascular abnormality, other possible causes of unilateral isolated hypoglossal nerve palsy include: an intracranial or extracranial space occupying lesion, head and neck injury, infection and autoimmune disease or neuropathy [9]. There are also some reports of idiopathic cases, which are usually reversible [9,10].
We describe the first paediatric case of unilateral hypoglossal nerve palsy due to neurovascular compression diagnosed by MRI combined with MRA and CT scan with three-dimensional reconstruction. On the basis of child’s symptoms (right-sided tongue atrophy, fasciculation and palsy) a peripheral lesion of the XII cranial nerve was suspected. SEPs abnormalities disclosed a dysfunction of the central somatosensory pathways at the brainstem level. The differential diagnosis of a peripheral unilateral cranial nerve palsy should include, even if rare in the paediatric age, a neurovascular conflict. In this case a complete neuroimaging study is indicated. In our patient, neuroimaging documented an abnormal tortuosity of the vertebrobasilar arteries compressing the brainstem at the emergency of the XII cranial nerve. This vascular abnormality is associated with an osseous malformation of the cranio-cervical junction, which could have contributed to the pathogenesis of the NC in our case. At present cranial nerve dysfunction syndromes are treated by surgical microvascular decompression, generally with good results [1,2]. Given the small of symptoms in our case, we decided to await the clinical evolution before performing a neurosurgical intervention. References [1] Lunardi P, Mastronardi L, Farah JO, De Biase C, Trasimeni G, Gualdi GE. Spinal accessory nerve palsy due to neurovascular compression. Report of a case diagnosed by magnetic resonance imaging and magnetic resonance angiography. Neurosurg Rev 1996;19:175–8. [2] Tomasello F, Alafaci C, Salpietro FM, Longo M. Bulbar compression by an ectatic vertebral artery: a novel neurovascular construct relieved by microsurgical decompression. Neurosurgery 2005;56:117–24. [3] Jannetta PJ. Neurovascular compression in cranial nerve and systemic disease. Ann Surg 1980;192:518–25.
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I. Toldo et al. / Brain & Development 31 (2009) 461–464
[4] Childs AM, Meaney JF, Ferrie CD, Holland PC. Neurovascular compression of the trigeminal and glossopharyngeal nerve: three case reports. Arch Dis Child 2000;82:311–5. [5] Borges A, Casselman J. Imaging the cranial nerves: part II: primary and secondary neoplastic conditions and neurovascular conflicts. Eur Radiol 2007;17:2332–44. [6] Shima F, Fukui M, Kitamura K, Kuromatsu C, Okamura T. Diagnosis and surgical treatment of spasmodic torticollis of the 11 nerve origin. Neurosurgery 1988;22:358–63. [7] De Ridder D, Menovsky T. Neurovascular compression of the abducent nerve causing abducent palsy treated by microvas-
cular decompression. Case report. J Neurosurg 2007;107: 1231–4. [8] Shiozawa Z, Koike G, Seguchi K, Shindo K, Sugita K. Unilateral tongue atrophy due to an enlarged emissary vein in the hypoglossal canal. Surg Neurol 1996;45:477–9. [9] Combarros O, Alvarez de Arcaya A, Berciano J. Isolated unilateral hypoglossal nerve palsy: nine cases. J Neurol 1998;245:98–100. [10] Giuffrida S, Lo Bartolo ML, Nicoletti A, Reggio E, Lo Fermo S, Restivo DA, et al. Isolated, unilateral, reversible palsy of the hypoglossal nerve. Eur J Neurol 2000;7:347–9.
Case report
Unilateral hypoglossal nerve palsy due to neurovascular conflict in a child Irene Toldo *, Renzo Manara, Stefano Sartori, Agnese Suppiej, Paola Drigo Department of Pediatrics, University of Padova, Via Giustiniani, 3, 35128 Padova, Italy Received 18 February 2008; received in revised form 30 March 2008; accepted 6 August 2008
Abstract A neurovascular conflict (NC) consists of a pathological contact between a vessel, generally an artery, and the root entry zone of a cranial nerve close to the brainstem. Even if NC of the V, VII and IX cranial nerve have been rarely described, to the best of our knowledge there is no report about the XII cranial nerve NC in the paediatric age. A three-year-old girl presented with right-sided tongue atrophy and fasciculation, of one-year-duration, consistent with a peripheral lesion of the right XII cranial nerve. Brain MRI and MRA documented a marked tortuosity of the vertebrobasilar arteries compressing the brainstem at the emergency of the XII cranial nerve, while the CT disclosed a concomitant osseous malformation of the cranio-cervical junction. The differential diagnosis of a peripheral unilateral cranial nerve palsy should include, even if rare in children, a neurovascular conflict. In this case a complete neuroimaging study is indicated. Ó 2008 Elsevier B.V. All rights reserved. Keywords: Neurovascular conflict; Hypoglossal nerve palsy; Unilateral; Tongue; Fasciculation; Vertebrobasilar arteries
1. Introduction A contact between a vessel, generally an artery, and the root entry zone of a cranial nerve close to the brainstem may cause a neurovascular conflict (NC). This condition is generally associated with a hyperactive cranial nerve dysfunction syndrome (neuralgia, spasm) [1]. Neurovascular conflict has been reported in adult patients affected by trigeminal or gloss pharyngeal neuralgia, hemifacial spasm or disabling positional vertigo. Other clinical syndromes related to brainstem compression, caused by anatomic variants of the vertebrobasilar arteries, comprise cerebellar dysfunction, hydrocephalus, ischemic stroke, pyramidal tract signs and lower cranial nerve dysfunction syndrome (dysphonia, dysphagia) [2].
These syndromes seem to be caused by unilateral vascular compression of a cranial nerve at the brainstem, especially at the root entry zone, which is the transition area between the peripheral and central myelin and is particularly vulnerable to continuous pulsatile pressure [3]. In paediatric patients, NC is a rare condition and only trigeminal and gloss pharyngeal neuralgias have been reported as clinical symptoms [4]. In the literature there are no reports of NC involving the hypoglossal nerve neither in adults nor in children. We present a child with unilateral hypoglossal nerve palsy and tongue fasciculation in whom a vascular contact to the XII cranial nerve is documented by magnetic resonance imaging (MRI) and MR-angiography (MRA). 2. Case report
*
Corresponding author. Tel.: +39 049 8218094; fax: +39 049 8213509. E-mail address: [email protected] (I. Toldo). 0387-7604/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.braindev.2008.08.009
A three-year-old girl presented to our clinic with right-sided tongue atrophy and fasciculation, of oneyear-duration. Her clinical history was unremarkable.
462
I. Toldo et al. / Brain & Development 31 (2009) 461–464
On neurological examination a partial deficit of motility with atrophy and fasciculation of right tongue was observed (Fig. 1). Palatine veil was symmetric. She had mild sialorrhea and rhinolalia and her expressive language was appropriate to the age. Cranial nerve XI function was normal. Phoniatric and audiologic evaluation didn’t reveal any other abnormality. Brain MRI and MRA disclosed elongated and tortuous vertebral arteries with a neurovascular compres-
sion of the medulla oblongata at the level of the right corticospinal tract and the right inferior olivary nucleus with involvement of the interposed anterior olivary sulcus, i.e. the hypoglossal nerve entry zone (Fig. 2a–f). CT (computer tomography) scan with three-dimensional reconstruction showed a coexistent atlo-occipital malformation with relative stenosis of the hypoglossal foramen (Fig. 3a–b). Electromyography study of right arm and trapezium was normal. Upper limb somatosensory evoked potentials (SEPs) showed an abnormal P14 component following left median nerve stimulation. The follow-up at 1 year revealed a stable clinical picture, the child never complained dysphagia. 3. Discussion
Fig. 1. Photograph of the patient’s tongue at 3 years of age. Patient’s tongue is deviated towards right due to partial deficit of unilateral hypoglossal nerve and it is atrophic on the right side.
Brainstem compression caused by anatomic variants of the vertebrobasilar arteries has been rarely reported; so far about 20 adult cases have been described [2]. A variety of clinical syndromes have been related to pulsatile compression by ectatic vertebrobasilar arteries: cerebellar dysfunction, hydrocephalus and ischemic stroke, as well as medulla oblongata compression [2].
Fig. 2. Cerebral MRI and MRA at 3 years of age. (a–b) Axial T2 images at the level of the medulla oblongata: the vertebral arteries (signal void indicated by white arrows) are elongated and tortuous; the brainstem is compressed particularly at the level of the right corticospinal tract and the right inferior olivary nucleus with involvement of the interposed anterior olivary sulcus (root entry zone of the hypoglossal nerve). (c) Axial T1 image at the same level of (b) showing the brainstem deformity. (d–e) Sagittal T1 images showing the medulla oblongata clearly distorted and angulated. (f) MRA of the circle of Willis (MIP 3D reconstruction) showing tortuosity of the inferior part of the vertebrobasilar arteries.
I. Toldo et al. / Brain & Development 31 (2009) 461–464
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Fig. 3. CT scan with 3D reconstruction at 3 years of age. (a) Axial image at the level of the hypoglossal foramen showing a relative stenosis on the right side. (b) CT 3D reconstruction (SSS technique) disclosing a coexistent atlo-occipital malformation.
Compression of the medulla oblongata has been reported to cause pyramidal tract signs, cranial nerve dysfunction syndrome and, more rarely, even sleep-disordered breathing (central or obstructive apnoea) [2]. MRI combined with MRA is the best modality in the diagnosis of NC by showing the course of the artery and the precise anatomic relationship between the vascular anomaly and the compressed medulla oblongata [2]. The cranial nerve dysfunction syndrome occurs because the nerve is particularly vulnerable to continuous pulsatile pressure at the root entry zone, which is the transition area between the peripheral and central myelin in the brainstem. The cranial nerves usually involved in NC are V, VII, VIII, IX and X [2–4,5]. There are few case reports of NC involving the VI and XI cranial nerves [6,7]. To the best of our knowledge, there are no reports about isolated NC of the XII cranial nerve neither in adults nor in children. Shiozawa reported a case of hypoglossal nerve palsy due to venous compression of the hypoglossal nerve by an enlarged emissary vein inside the hypoglossal canal [8]. In this case the XII nerve compression was determined by a space occupying venous lesion so it cannot be strictly considered as a NC, because the enlarged vein does not apply a pulsatile pression on the nerve. In fact strict criteria for neurovascular conflict state that the offending vessel must be an artery, the site of contact must be the root entry zone, the vessel must cross the nerve perpendicularly, and the nerve must be deviated or indented by the vessel or compressed or encased between two or more adjacent vessels in the appropriate clinical setting [5]. As well as a vascular abnormality, other possible causes of unilateral isolated hypoglossal nerve palsy include: an intracranial or extracranial space occupying lesion, head and neck injury, infection and autoimmune disease or neuropathy [9]. There are also some reports of idiopathic cases, which are usually reversible [9,10].
We describe the first paediatric case of unilateral hypoglossal nerve palsy due to neurovascular compression diagnosed by MRI combined with MRA and CT scan with three-dimensional reconstruction. On the basis of child’s symptoms (right-sided tongue atrophy, fasciculation and palsy) a peripheral lesion of the XII cranial nerve was suspected. SEPs abnormalities disclosed a dysfunction of the central somatosensory pathways at the brainstem level. The differential diagnosis of a peripheral unilateral cranial nerve palsy should include, even if rare in the paediatric age, a neurovascular conflict. In this case a complete neuroimaging study is indicated. In our patient, neuroimaging documented an abnormal tortuosity of the vertebrobasilar arteries compressing the brainstem at the emergency of the XII cranial nerve. This vascular abnormality is associated with an osseous malformation of the cranio-cervical junction, which could have contributed to the pathogenesis of the NC in our case. At present cranial nerve dysfunction syndromes are treated by surgical microvascular decompression, generally with good results [1,2]. Given the small of symptoms in our case, we decided to await the clinical evolution before performing a neurosurgical intervention. References [1] Lunardi P, Mastronardi L, Farah JO, De Biase C, Trasimeni G, Gualdi GE. Spinal accessory nerve palsy due to neurovascular compression. Report of a case diagnosed by magnetic resonance imaging and magnetic resonance angiography. Neurosurg Rev 1996;19:175–8. [2] Tomasello F, Alafaci C, Salpietro FM, Longo M. Bulbar compression by an ectatic vertebral artery: a novel neurovascular construct relieved by microsurgical decompression. Neurosurgery 2005;56:117–24. [3] Jannetta PJ. Neurovascular compression in cranial nerve and systemic disease. Ann Surg 1980;192:518–25.
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I. Toldo et al. / Brain & Development 31 (2009) 461–464
[4] Childs AM, Meaney JF, Ferrie CD, Holland PC. Neurovascular compression of the trigeminal and glossopharyngeal nerve: three case reports. Arch Dis Child 2000;82:311–5. [5] Borges A, Casselman J. Imaging the cranial nerves: part II: primary and secondary neoplastic conditions and neurovascular conflicts. Eur Radiol 2007;17:2332–44. [6] Shima F, Fukui M, Kitamura K, Kuromatsu C, Okamura T. Diagnosis and surgical treatment of spasmodic torticollis of the 11 nerve origin. Neurosurgery 1988;22:358–63. [7] De Ridder D, Menovsky T. Neurovascular compression of the abducent nerve causing abducent palsy treated by microvas-
cular decompression. Case report. J Neurosurg 2007;107: 1231–4. [8] Shiozawa Z, Koike G, Seguchi K, Shindo K, Sugita K. Unilateral tongue atrophy due to an enlarged emissary vein in the hypoglossal canal. Surg Neurol 1996;45:477–9. [9] Combarros O, Alvarez de Arcaya A, Berciano J. Isolated unilateral hypoglossal nerve palsy: nine cases. J Neurol 1998;245:98–100. [10] Giuffrida S, Lo Bartolo ML, Nicoletti A, Reggio E, Lo Fermo S, Restivo DA, et al. Isolated, unilateral, reversible palsy of the hypoglossal nerve. Eur J Neurol 2000;7:347–9.