Confidential: For Review Only - WordPress.com · Confidential: For Review Only Conjugate upward gaze paralysis with unilateral ptosis caused by a unilateral midbrain infarction Bruno

Confidential: For Review O

nly

Conjugate upward gaze paralysis with unilateral ptosis

caused by a unilateral midbrain infarction

Journal: Journal of Neurology, Neurosurgery, and Psychiatry

Manuscript ID: jnnp-2013-305448.R2

Article Type: Neurological picture

Date Submitted by the Author: n/a

Complete List of Authors: dos Santos, Bruno; Medical School of Ribeirão Preto, University of São Paulo, Neurosciences and Behavioral Sciences Simão, Gustavo; Medical School of Ribeirão Preto, University of São Paulo, Image Sciences and Medical Physics Centre Pontes-Neto, Octávio; Medical School of Ribeirão Preto, University of São Paulo, Neurosciences and Behavioral Sciences

Keywords: STROKE, EYE MOVEMENTS, OPHTHALMOLOGY

<b>Specialty</b>: Neuro-ophthalmology

http://mc.manuscriptcentral.com/jnnp

Journal of Neurology, Neurosurgery, and Psychiatry


nlyConjugate upward gaze paralysis with unilateral ptosis caused by a unilateral midbrain

infarction

Bruno Lopes dos Santos1, Gustavo Novelino Simão2, Octávio Marques Pontes-Neto1

1 Department of Neuroscience and Behavior Sciences, Medical School of Ribeirão Preto,

University of São Paulo, Ribeirão Preto, SP, Brazil.

2 Image Sciences and Medical Physics Centre, Medical School of Ribeirão Preto, University of

São Paulo, Ribeirão Preto, SP, Brazil.

Word Count: 502 words.

Number of References: 8 references.

Corresponding Author Email: [email protected]

A 73-years old woman with atrial fibrillation presented with a sudden right hemiparesis,

with diplopia and left ptosis, and was admitted at an Emergency Unit. The neurological

examination showed fluctuations on consciousness level, predominant crural right hemiparesis,

right central facial paralysis without sensitive abnormalities. The first ophthalmological evaluation

showed normal pupillary reflexes, total left ptosis, paresis of adduction of the left eye, with

conjugated horizontal palsy for right gaze and conjugated vertical palsy for upward and downward

gaze on saccadic and smooth pursuit eye movements. The convergence showed paresis of left

eye, with reactive pupils, and oculocephalic test was normal. A head computed tomography (CT)

had no acute ischemic signs, and after four days, she was discharged. The brain magnetic

Page 1 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nlyresonance (MR) performed 15 days after the ictus showed a clearly defined left paramedian

tegmental mesencephalic infarct (Figure 1). Two months after the stroke, the patient had a

remarkable improvement of ocular motility, presenting paresis of levator palpebrae, medial and

inferior rectus muscles of the left eye, with conjugate vertical upward gaze palsy in saccadic and

smooth pursuit (Figure 2).

The control of the vertical gaze within the brainstem is mediated by three main nuclei: the

nucleus of rostral interstitial medial longitudinal fasciculus (riMLF), the interstitial nucleus of Cajal

(INC) and nucleus of the posterior commissure (NPC) [1]. In primates, there is a coordinated

action among the three nuclei for vertical gaze generation, but the INC and NPC have a main role

in upward eye control [1]. The riMLF/INC/NPC system projects its axons, through the medial

longitudinal fasciculus (MLF), to the oculomotor complex (OC) by distinct pathways: in upward

gaze, these fibers innervate both ipsilateral and contralateral elevator muscles subnuclei (rectus

superior and oblique inferior) of OC simultaneously; in downward gaze, the projections to rectus

inferior and oblique superior run predominantly ipsilateral [1, 2]. There are important connections

between these MRF nuclei, and due its proximity, small lesions of MRF can affect all of them [2,

3]. Ptosis is caused by a lesion in central caudal nucleus (CCN) neurons or its fibers. The CCN

innervates both levator palpebrae muscles [1]. Classically, midbrain lesions affecting the CCN

lead to bilateral ptosis [4], but partial lesions of the oculomotor fascicle, situated in the

paramedian ventral midbrain, can cause unilateral ptosis [5].

Our patient had an unusual association of neurological abnormalities. This combination of

eye movement disorders and right hemiparesis could be explained by a left paramedian midbrain

lesion, at the level of: (1) the riMLF/INC/NPC system fibers projecting to the OC (mainly the INC

and NPC axons), causing the vertical gaze palsy, (2) left oculomotor fascicle, associated with the

total left ptosis with medial and inferior rectus palsies, sparing the pupil, and (3) left cerebral

peduncle, explaining right hemiparesis (Figure 3). There are others descriptions of unilateral

Page 2 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nlymidbrain lesions causing supranuclear vertical gaze paralysis [3, 6, 7, 8], but no case had

unilateral ptosis. This case shows the complexity of supranuclear eye movement control and the

intrinsic relationship among the midbrain reticular formation nuclei.

FOOTNOTES

Acknowledgements: We would like to thank Maria Lúcia Habib Simão, M.D., for the essential

corrections and comments about the text.

Competing interests: None.

Patient consent: Obtained.

Provenance and peer review: Not commissioned; externally peer reviewed.

REFERENCES

1. Büttner-Ennever JA, Horn AKE. Reticular Formation: Eye Movements, Gaze, and Blinks. In:

Paxinos G, Mai JK, eds. The Human Nervous System. San Diego, CA: Elsevier Academic Press,

2004:479-510.

2. Moschovakis AK, Scudder CA, Highstein SM. Structure of the primate oculomotor burst

generator. I. Medium-lead burst neurons with upward on-directions. J Neurophysiol.

1991;65(2):203-17.

3. Hommel M, Bogousslavsky J. The spectrum of vertical gaze palsy following unilateral

brainstem stroke. Neurology. 1991;41:1229-34.

4. Averbuch-Heller L. Neurology of the eyelids. Curr Opin Ophthalmol. 1997;8(6):27-34.

Page 3 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nly5. Miura K, Nagaoka T, Ikeda K, et al. A case of inferolateral oculomotor fascicular infarction: a

review of the clinicoradiological literature. Intern Med 2012;51(8):921-4.

6. Smith MS, Laguna JF. Upward gaze paralysis following unilateral pretectal infarction.

Computadorized tomography correlation. Arch Neurol 1984;38:127-9.

7. Ranalli PJ, Sharpe JA, Fletcher WA. Palsy of upward and downward saccadic, pursuit, and

vestibular movements with a unilateral midbrain lesion: pathophysiologic correlations. Neurology

1988;38:114-22.

8. Rabadi MH. Unilateral midbrain infarct presenting as dorsal midbrain syndrome. J Neurol

Neurosurg Psychiatry (Published Online First):[2013 Apr 5] doi:10.1136/jnnp-2013-304883.

Page 4 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nlyLEGENDS

Figure 1 – MR images from the case. A: Axial T2 FLAIR. B: Axial diffusion weighted MR image.

C: ADC map, showing a small acute infarction (arrow) in the left paramedian tegmental midbrain.

Figure 2 – Positions of gaze. A: Forward gaze in primary position, with elevation of eyelids. B:

Forward gaze in primary position (showing left ptosis). C: Upward gaze (with bilateral conjugated

upward gaze palsy). D: Downward gaze (showing downward paresis of left eye). E: Right gaze

(with adduction paresis of left eye). F: Left gaze.

Figure 3 – Anatomic scheme of brainstem nuclei associated with control of eye movement, in

sagittal and axial view. A: Structures of vertical gaze control, in sagittal view, with two levels (B

and C) delimited through midbrain. B and C: Axial sections from the levels indicated in A. The

shaded area indicates the presumed site of lesion. 3N, oculomotor nucleus; 3f, oculomotor

fascicle; 3n, oculomotor nerve; 4N, trochlear nucleus; 6N, abducens nucleus; 6f, abducens

fascicle; CCN, central caudal nucleus; CP, cerebral peduncle; CTG, central tegmental tract; INC,

interstitial nucleus of Cajal; MLF, medial longitudinal fascicle; MmB, mammilary body; OC, olivary

complex; PC, posterior commissure; riMLF, rostral interstitial nucleus of the medial longitudinal

fascicle; SC, superior colliculus (figure modified from [1]).

Page 5 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nly

MR images from the case. A: Axial T2 FLAIR. B: Axial diffusion weighted MR image. C: ADC map, showing a small acute infarction (arrow) in the left paramedian tegmental midbrain.

180x55mm (300 x 300 DPI)

Page 6 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nly

Positions of gaze. A: Forward gaze in primary position, with elevation of eyelids. B: Forward gaze in primary position (showing left ptosis). C: Upward gaze (with bilateral conjugated upward gaze palsy). D: Downward gaze (showing downward paresis of left eye). E: Right gaze (with right paresis of left eye). F: Left gaze.

180x118mm (300 x 300 DPI)

Page 7 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nly

180x121mm (300 x 300 DPI)

Page 8 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nlyMULTIPLE CHOICE QUESTION - IMAGE QUIZ

A 73-years old woman presented suddenly a right hemiparesis, with left ptosis, left medial and

inferior rectus muscles palsy, and a conjugated upward vertical gaze palsy (Figure 2). MR image

showed a left paramedian tegmental mesencephalic infarct (Figure 1). Which is the most

common affected artery on this topography?

Options:

a) Superior cerebellar artery

b) Posterior thalamo-subthalamic paramedian artery

c) Posterior communicating artery

d) Anterior choroidal artery

e) Distal branches of middle cerebral artery

Correct answer:

b) Posterior thalamo-subthalamic paramedian artery

Explanation: Midbrain infarcts occur in 1% of all ischemic strokes, and isolated midbrain ischemic

strokes are found in 0,7% of all posterior circulation infarcts [1]. The most common affected

vessel is the posterior thalamo-subthalamic paramedian artery, a branch of the basilar artery on

its top, and the unilateral lesion is more frequent in midbrain strokes [2], which also can be

described as medial mesencephalic branches of top of basilar [3]. Reporting 21 cases of isolated

Page 9 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960


nlymidbrain infarct, Ogawa et al. noted that the paramedian region was the most affected area of

midbrain, causing a multitude of clinical signs, as hemiparesis, ataxia, eye movement disorders,

including ptosis and pupil defects [3].

Bruno Lopes dos Santos, Gustavo Novelino Simão, Octávio Marques Pontes-Neto

Medical School of Ribeirão Preto, Ribeirão Preto, SP, Brazil

REFERENCES

1. Kumral E, Bayulkem G, Akyol A, et al. Mesencephalic and associated posterior circulation

infarcts. Stroke. 2002;33(9):2224-31.

2. Wall M, Slamovits TL, Weisberg LA, et al. Vertical gaze ophthalmoplegia from infarction in the

area of the posterior thalamo-subthalamic paramedian artery. Stroke. 1986;17(3):546-55.

3. Ogawa K, Suzuki Y, Oishi M, et al. Clinical study of twenty-one patients with pure midbrain

infarction. Eur Neurol 2012;67(2):81-9.

Page 10 of 10



123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960

Documents

Confidential: For Review Only - WordPress.com · Confidential: For Review Only Conjugate upward gaze paralysis with unilateral ptosis caused by a unilateral midbrain infarction Bruno