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Evolution of torsional-upbeat into hemi-seesaw nystagmus in medial medullary infarction
Clinical Neurology and Neurosurgery 118 (2014) 80–82
Contents lists available at ScienceDirect
Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro
Evolution of torsional-upbeat into hemi-seesaw nystagmus in medial medullary infarction Sun-Uk Lee a,1 , Seong-Ho Park b,1 , Seong-Hae Jeong c , Hyo-Jung Kim d , Ji-Soo Kim b,∗ a
Department of Neurology, Ajou University School of Medicine, Ajou University Hospital, Suwon, South Korea Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea Department of Neurology, Chungnam National University Hospital, Daejon, South Korea d Kangwon National University College of Medicine, Biomedical Research Institute, Seoul National University Bundang Hospital, Seongnam, South Korea b c
a r t i c l e
i n f o
Article history: Received 16 November 2013 Received in revised form 28 December 2013 Accepted 2 January 2014 Available online 14 January 2014 Keywords: Vertigo Nystagmus Hemi-seesaw nystagmus Medullary infarction
1. Introduction Hemi-seesaw nystagmus refers to mixed torsional-vertical jerky nystagmus with conjugate torsional components and the vertical components in the opposite directions [1]. Based on the evolution of upbeat into jerky seesaw nystagmus in a patient with medial medullary infarction (MMI) [2], disruption of the vestibulo-ocular reflex (VOR) pathways from the vertical semicircular canals was proposed as a mechanism of hemi-seesaw nystagmus. This presumption was supported by following reports on jerky seesaw nystagmus in patients with internuclear ophthalmoplegia (INO) from lesions involving the MLF which is believed to carry the fibers for the vertical VOR originating from the contralateral vertical canals [3,4]. The authors have proposed three distinctive patterns of mixed torsional-vertical jerky nystagmus according to the vertical VOR pathways involved [3,4]. Herein, we describe evolution of torsional-upbeat nystagmus into hemi-seesaw nystagmus in a patient with MMI. This evolution provides further evidence that
∗ Corresponding author at: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea. Tel.: +82 31 787 7463; fax: +82 31 719 6828. E-mail address: [email protected] (J.-S. Kim). 1 These authors equally contributed to this work. 0303-8467/$ – see front matter © 2014 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.clineuro.2014.01.003
hemi-seesaw nystagmus results from disruption of the vertical VOR pathways. 2. Case report A 62-year-old woman with hypertension and diabetes mellitus for 6 years developed sudden vertigo. She showed left hypertropia and spontaneous nystagmus with mixed leftward, counter-clockwise torsional (the upper pole of the eyes beating to the left ear) and upbeat components. Spontaneous nystagmus measured with video-oculography (VOG) was mainly upbeating in the right eye and mostly torsional in the left eye (Video 1). This pattern of nystagmus did not change during horizontal or vertical gazes. Gaze-evoked nystagmus was present during lateral gazes. She also showed rightward ocular lateropulsion. Horizontal head impulse test was normal in both directions. Remainder of the neurological examination was unrevealing without tongue deviation, hemiparesis or sensory changes. MRI and MR angiography showed an acute infarction in the left rostral medial medulla with hypoplastic left vertebral artery (Fig 1A and B). Fundus photography showed clockwise (from the patient’s perspective) contraversive torsion of the eyes (23.6◦ in the right eye, –7.4◦ in the left eye, normal range: 0–12.6◦ , negative value indicates intorsion, Fig. 1C). She also showed contraversive rightward tilt of the subjective visual vertical (SVV, 11.0◦ in the right eye, 11.1◦ in the left eye, normal range: –3.1◦ to 3.0◦ , positive value indicates rightward tilt). The results of bithermal caloric tests were normal.
S.-U. Lee et al. / Clinical Neurology and Neurosurgery 118 (2014) 80–82
Fig. 1. (A) Diffusion-weighted MRI shows an acute infarction involving left rostral medial medulla. (B) MR angiography discloses hypoplastic left vertebral artery (arrow). (C) Fundus photography demonstrates rightward torsion of both eyes.
Of interest, follow-up evaluation three days later showed hemiseesaw nystagmus that had conjugate counter-clockwise torsional nystagmus in both eyes, concurrent with downbeat nystagmus in the left eye and upbeat nystagmus in the right eye (Video 1). Besides, skew deviation became more prominent. Antiplatelet agent was started and she was discharged eight days after symptom onset. Two months later, the hemi-seesaw nystagmus almost resolved with subtle residual counter-clockwise torsional nystagmus in both eyes. 3. Discussion This is the first report on evolution of dissociated torsionalupbeat nystagmus into hemi-seesaw nystagmus. In our patient with unilateral infarction involving the medial medulla, dissociated torsional-upbeat nystagmus evolved into jerky seesaw nystagmus
81
with the vertical components in the opposite directions in both eyes. Previously, torsional nystagmus with asymmetric upbeat components in both eyes has been ascribed to disruption of the pathways from the anterior semicircular canal while hemi-seesaw nystagmus with the vertical components in the opposite direction has been attributed to damage to the fibers from both anterior and posterior semicircular canals [2–4]. In our patient, the initial torsional-upbeat nystagmus may be explained by selective damage to the VOR pathway from the contralesional anterior semicircular canal while the hemi-seesaw nystagmus may be ascribed to additional damage to the VOR pathway from the contralesional posterior semicircular canal (Video 2) [2–4]. Since the excitatory fibers from the anterior canal innervate ipsilateral superior rectus and contralateral inferior oblique, damage to this pathway in the upper medulla after decussation would cause primarily a downward deviation of the contralesional eye and intorsion of the ipsilesional eye, and resulting corrective quick phases of nystagmus beating mostly upward in the contralesional eye and mostly extorsional in the ipsilesional eye (Fig. 2A). In contrast, since the posterior canal innervates ipsilateral superior oblique and contralateral inferior rectus, additional damage to the posterior canal fibers after crossing would result in tonic contraversive torsion of the eyes and corrective ipsiversive torsional nystagmus and the vertical nystagmus in the opposite directions due to a partial cancellation of the vertical actions between the vertical rectus and oblique muscles in each eye (Fig. 2B). Previously, a patient with upbeat nystagmus from bilateral MMI showed an evolution into hemi-seesaw nystagmus after resolution of unilateral lesion [2]. In that patient, the initial upbeat nystagmus was explained by disruption of the fibers from both anterior semicircular canals due to bilateral lesions while the subsequent hemi-seesaw nystagmus has been ascribed to damage to the pathway only from the contralateral anterior canal along with resolution of unilateral lesion in the medulla. Our current patient provides further evidence that hemi-seesaw nystagmus results from disruption of the vertical VOR pathways. Besides the hemi-seesaw nystagmus, our patient showed contraversive OTR and SVV tilt and ocular contrapulsion. The contraversive OTR and SVV tilt is ascribed to the disruption of the utricular pathway after decussation in the lower pons [5]. Otherwise, the OTR itself may be a manifestation of disrupted vertical VOR pathway [4,5].
Fig. 2. (A) Illustration of the mechanism of dissociated torsional-upbeat nystagmus and hemi-seesaw nystagmus in our patient. Dissociated torsional-upbeat nystagmus may be ascribed to damage to the pathway from the contralateral anterior canal, which innervates the ipsilesional inferior oblique (mainly extortor) and contralesional superior rectus (mainly elevator). (B) An additional damage to the pathway from the contralateral posterior canal would result in hemi-seesaw nystagmus with a conjugate torsional nystagmus, but the vertical nystagmus in the opposite directions due to a partial cancellation of the vertical actions between the vertical rectus and oblique muscles in each eye. The arrows indicate quick phases of nystagmus and bars represent damage to the canal pathways after decussation in the upper medulla. AC, anterior semicircular canal; PC, posterior semicircular canal; VN, vestibular nucleus; VI, abducens nucleus; IV, trochlear nucleus; III, oculomotor nucleus; IO, inferior oblique; IR, inferior rectus; SO, superior oblique; SR, superior rectus.
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S.-U. Lee et al. / Clinical Neurology and Neurosurgery 118 (2014) 80–82
Disruption of the olivocerebellar fibers may generate horizontal ocular motor bias. When the fibers are damaged after decussation, likewise in Wallenberg syndrome, the bias is toward the lesion side (ipsipulsion) [1]. In contrast, interruption of the olivocerebellar fibers before decussation, as in MMI, results in ocular contrapulsion [1]. In our patient, the ocular contrapulsion may be explained by damage to the olivocerebellar fibers before decussation in the upper medulla [1].
revised the manuscript. Ms. H.J. Kim analyzed and interpreted the data, and revised the manuscript. Dr. J.S. Kim conducted the design and conceptualization of the study, interpretation of the data, and drafting and revising the manuscript.
4. Conclusion
Appendix A. Supplementary data
In conclusion, the evolution of dissociated torsional-upbeat into hemi-seesaw nystagmus in our patient with MMI may be explained by disruption of the pathways from the vertical canals. Selective disruption of anterior semicircular canal may have caused the dissociated torsional-upbeat nystagmus while the evolution into hemi-seesaw nystagmus may be ascribed to additional damage to the VOR pathway from the contralesional posterior semicircular canal.
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.plantsci.2004.08. 011http://dx.doi.org/10.1016/j.plantsci.2004.08.011.
Conflict of interest Authors declare that there is no conflict of interest. Authors contribution Drs. Lee and Park wrote the manuscript and analyzed and interpreted the data. Dr. Jeong analyzed and interpreted the data, and
Disclosure Lee, Park, Jeong, H.J. Kim, and J.S. Kim report no disclosures.
References [1] Leigh RJ, Zee DS. In: The neurology of eye movements. 4th ed. New York: Oxford University Press; 2006. [2] Choi KD, Jung DS, Park KP, Jo JW, Kim JS. Bowtie and upbeat nystagmus evolving into hemi-seesaw nystagmus in medial medullary infarction: possible anatomic mechanisms. Neurology 2004;62:663–5. [3] Jeong SH, Kim EK, Lee J, Choi KD, Kim JS. Patterns of dissociated torsional-vertical nystagmus in internuclear ophthalmoplegia. Ann N Y Acad Sci 2011;1233:271–8. [4] Lee SU, Kim HJ, Kim JS. Evolution of symmetric upbeat into dissociated torsional-upbeat nystagmus in internuclear ophthalmoplegia. Clin Neurol Neurosurg 2013, http://dx.doi.org/10.1016/j.clineuro.2013.04.003, pii: S0303-8467(13)00123-6 [Epub ahead of print]. [5] Brandt T, Dieterich M. Central vestibular syndromes in roll, pitch, and yaw planes: topographic diagnosis of brainstem disorders. Neuro-ophthalmology 1995;15:291–303.
Contents lists available at ScienceDirect
Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro
Evolution of torsional-upbeat into hemi-seesaw nystagmus in medial medullary infarction Sun-Uk Lee a,1 , Seong-Ho Park b,1 , Seong-Hae Jeong c , Hyo-Jung Kim d , Ji-Soo Kim b,∗ a
Department of Neurology, Ajou University School of Medicine, Ajou University Hospital, Suwon, South Korea Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea Department of Neurology, Chungnam National University Hospital, Daejon, South Korea d Kangwon National University College of Medicine, Biomedical Research Institute, Seoul National University Bundang Hospital, Seongnam, South Korea b c
a r t i c l e
i n f o
Article history: Received 16 November 2013 Received in revised form 28 December 2013 Accepted 2 January 2014 Available online 14 January 2014 Keywords: Vertigo Nystagmus Hemi-seesaw nystagmus Medullary infarction
1. Introduction Hemi-seesaw nystagmus refers to mixed torsional-vertical jerky nystagmus with conjugate torsional components and the vertical components in the opposite directions [1]. Based on the evolution of upbeat into jerky seesaw nystagmus in a patient with medial medullary infarction (MMI) [2], disruption of the vestibulo-ocular reflex (VOR) pathways from the vertical semicircular canals was proposed as a mechanism of hemi-seesaw nystagmus. This presumption was supported by following reports on jerky seesaw nystagmus in patients with internuclear ophthalmoplegia (INO) from lesions involving the MLF which is believed to carry the fibers for the vertical VOR originating from the contralateral vertical canals [3,4]. The authors have proposed three distinctive patterns of mixed torsional-vertical jerky nystagmus according to the vertical VOR pathways involved [3,4]. Herein, we describe evolution of torsional-upbeat nystagmus into hemi-seesaw nystagmus in a patient with MMI. This evolution provides further evidence that
∗ Corresponding author at: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea. Tel.: +82 31 787 7463; fax: +82 31 719 6828. E-mail address: [email protected] (J.-S. Kim). 1 These authors equally contributed to this work. 0303-8467/$ – see front matter © 2014 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.clineuro.2014.01.003
hemi-seesaw nystagmus results from disruption of the vertical VOR pathways. 2. Case report A 62-year-old woman with hypertension and diabetes mellitus for 6 years developed sudden vertigo. She showed left hypertropia and spontaneous nystagmus with mixed leftward, counter-clockwise torsional (the upper pole of the eyes beating to the left ear) and upbeat components. Spontaneous nystagmus measured with video-oculography (VOG) was mainly upbeating in the right eye and mostly torsional in the left eye (Video 1). This pattern of nystagmus did not change during horizontal or vertical gazes. Gaze-evoked nystagmus was present during lateral gazes. She also showed rightward ocular lateropulsion. Horizontal head impulse test was normal in both directions. Remainder of the neurological examination was unrevealing without tongue deviation, hemiparesis or sensory changes. MRI and MR angiography showed an acute infarction in the left rostral medial medulla with hypoplastic left vertebral artery (Fig 1A and B). Fundus photography showed clockwise (from the patient’s perspective) contraversive torsion of the eyes (23.6◦ in the right eye, –7.4◦ in the left eye, normal range: 0–12.6◦ , negative value indicates intorsion, Fig. 1C). She also showed contraversive rightward tilt of the subjective visual vertical (SVV, 11.0◦ in the right eye, 11.1◦ in the left eye, normal range: –3.1◦ to 3.0◦ , positive value indicates rightward tilt). The results of bithermal caloric tests were normal.
S.-U. Lee et al. / Clinical Neurology and Neurosurgery 118 (2014) 80–82
Fig. 1. (A) Diffusion-weighted MRI shows an acute infarction involving left rostral medial medulla. (B) MR angiography discloses hypoplastic left vertebral artery (arrow). (C) Fundus photography demonstrates rightward torsion of both eyes.
Of interest, follow-up evaluation three days later showed hemiseesaw nystagmus that had conjugate counter-clockwise torsional nystagmus in both eyes, concurrent with downbeat nystagmus in the left eye and upbeat nystagmus in the right eye (Video 1). Besides, skew deviation became more prominent. Antiplatelet agent was started and she was discharged eight days after symptom onset. Two months later, the hemi-seesaw nystagmus almost resolved with subtle residual counter-clockwise torsional nystagmus in both eyes. 3. Discussion This is the first report on evolution of dissociated torsionalupbeat nystagmus into hemi-seesaw nystagmus. In our patient with unilateral infarction involving the medial medulla, dissociated torsional-upbeat nystagmus evolved into jerky seesaw nystagmus
81
with the vertical components in the opposite directions in both eyes. Previously, torsional nystagmus with asymmetric upbeat components in both eyes has been ascribed to disruption of the pathways from the anterior semicircular canal while hemi-seesaw nystagmus with the vertical components in the opposite direction has been attributed to damage to the fibers from both anterior and posterior semicircular canals [2–4]. In our patient, the initial torsional-upbeat nystagmus may be explained by selective damage to the VOR pathway from the contralesional anterior semicircular canal while the hemi-seesaw nystagmus may be ascribed to additional damage to the VOR pathway from the contralesional posterior semicircular canal (Video 2) [2–4]. Since the excitatory fibers from the anterior canal innervate ipsilateral superior rectus and contralateral inferior oblique, damage to this pathway in the upper medulla after decussation would cause primarily a downward deviation of the contralesional eye and intorsion of the ipsilesional eye, and resulting corrective quick phases of nystagmus beating mostly upward in the contralesional eye and mostly extorsional in the ipsilesional eye (Fig. 2A). In contrast, since the posterior canal innervates ipsilateral superior oblique and contralateral inferior rectus, additional damage to the posterior canal fibers after crossing would result in tonic contraversive torsion of the eyes and corrective ipsiversive torsional nystagmus and the vertical nystagmus in the opposite directions due to a partial cancellation of the vertical actions between the vertical rectus and oblique muscles in each eye (Fig. 2B). Previously, a patient with upbeat nystagmus from bilateral MMI showed an evolution into hemi-seesaw nystagmus after resolution of unilateral lesion [2]. In that patient, the initial upbeat nystagmus was explained by disruption of the fibers from both anterior semicircular canals due to bilateral lesions while the subsequent hemi-seesaw nystagmus has been ascribed to damage to the pathway only from the contralateral anterior canal along with resolution of unilateral lesion in the medulla. Our current patient provides further evidence that hemi-seesaw nystagmus results from disruption of the vertical VOR pathways. Besides the hemi-seesaw nystagmus, our patient showed contraversive OTR and SVV tilt and ocular contrapulsion. The contraversive OTR and SVV tilt is ascribed to the disruption of the utricular pathway after decussation in the lower pons [5]. Otherwise, the OTR itself may be a manifestation of disrupted vertical VOR pathway [4,5].
Fig. 2. (A) Illustration of the mechanism of dissociated torsional-upbeat nystagmus and hemi-seesaw nystagmus in our patient. Dissociated torsional-upbeat nystagmus may be ascribed to damage to the pathway from the contralateral anterior canal, which innervates the ipsilesional inferior oblique (mainly extortor) and contralesional superior rectus (mainly elevator). (B) An additional damage to the pathway from the contralateral posterior canal would result in hemi-seesaw nystagmus with a conjugate torsional nystagmus, but the vertical nystagmus in the opposite directions due to a partial cancellation of the vertical actions between the vertical rectus and oblique muscles in each eye. The arrows indicate quick phases of nystagmus and bars represent damage to the canal pathways after decussation in the upper medulla. AC, anterior semicircular canal; PC, posterior semicircular canal; VN, vestibular nucleus; VI, abducens nucleus; IV, trochlear nucleus; III, oculomotor nucleus; IO, inferior oblique; IR, inferior rectus; SO, superior oblique; SR, superior rectus.
82
S.-U. Lee et al. / Clinical Neurology and Neurosurgery 118 (2014) 80–82
Disruption of the olivocerebellar fibers may generate horizontal ocular motor bias. When the fibers are damaged after decussation, likewise in Wallenberg syndrome, the bias is toward the lesion side (ipsipulsion) [1]. In contrast, interruption of the olivocerebellar fibers before decussation, as in MMI, results in ocular contrapulsion [1]. In our patient, the ocular contrapulsion may be explained by damage to the olivocerebellar fibers before decussation in the upper medulla [1].
revised the manuscript. Ms. H.J. Kim analyzed and interpreted the data, and revised the manuscript. Dr. J.S. Kim conducted the design and conceptualization of the study, interpretation of the data, and drafting and revising the manuscript.
4. Conclusion
Appendix A. Supplementary data
In conclusion, the evolution of dissociated torsional-upbeat into hemi-seesaw nystagmus in our patient with MMI may be explained by disruption of the pathways from the vertical canals. Selective disruption of anterior semicircular canal may have caused the dissociated torsional-upbeat nystagmus while the evolution into hemi-seesaw nystagmus may be ascribed to additional damage to the VOR pathway from the contralesional posterior semicircular canal.
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.plantsci.2004.08. 011http://dx.doi.org/10.1016/j.plantsci.2004.08.011.
Conflict of interest Authors declare that there is no conflict of interest. Authors contribution Drs. Lee and Park wrote the manuscript and analyzed and interpreted the data. Dr. Jeong analyzed and interpreted the data, and
Disclosure Lee, Park, Jeong, H.J. Kim, and J.S. Kim report no disclosures.
References [1] Leigh RJ, Zee DS. In: The neurology of eye movements. 4th ed. New York: Oxford University Press; 2006. [2] Choi KD, Jung DS, Park KP, Jo JW, Kim JS. Bowtie and upbeat nystagmus evolving into hemi-seesaw nystagmus in medial medullary infarction: possible anatomic mechanisms. Neurology 2004;62:663–5. [3] Jeong SH, Kim EK, Lee J, Choi KD, Kim JS. Patterns of dissociated torsional-vertical nystagmus in internuclear ophthalmoplegia. Ann N Y Acad Sci 2011;1233:271–8. [4] Lee SU, Kim HJ, Kim JS. Evolution of symmetric upbeat into dissociated torsional-upbeat nystagmus in internuclear ophthalmoplegia. Clin Neurol Neurosurg 2013, http://dx.doi.org/10.1016/j.clineuro.2013.04.003, pii: S0303-8467(13)00123-6 [Epub ahead of print]. [5] Brandt T, Dieterich M. Central vestibular syndromes in roll, pitch, and yaw planes: topographic diagnosis of brainstem disorders. Neuro-ophthalmology 1995;15:291–303.