중뇌 병변에서의 신경안과/신경이과적 진찰
이선욱
1,21고려대 안암병원 신경과, 2서울대학교 의학과
Neurotologic and Neurotologic Findings in Midbrain Lesion
Sun-Uk Lee, MD
1,21Department of Neurology, Korea University Medical Center, Seoul; 2Department of Neurology, Seoul National University College of Medicine, Seoul, Korea
The midbrain is a key structure in the control of vertical eye movement. Three structures play key roles in the control of vertical
gaze in the midbrain: the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), interstitial nucleus of Cajal, poste-
rior commissure, as well as the oculomotor and trochlear nucleus. In evaluating the patient with vertical gaze palsies from mid-
brain lesion, clinical should evaluate the ocular alignment, looking for oculomotor or trochlear palsy, and skew deviation. Besides,
examination of the saccades, smooth pursuit, vestibular-ocular reflex (VOR) or vergence eye movements should be conducted
since a lesion in midbrain can selectively impair those eye movements. It is also important to assess the integrity of torsional VOR,
noting whether quick phases of nystagmus occur in both directions as the patient’s head rolls from side to side. As well as the eye
movements, clinician should also look for abnormalities of the eyelids and pupil for a proper diagnosis.
NONO findings in midbrain
2020.11.7 안신경의학회 추계학술대회
고대안암병원 신경과 임상조교수 이선욱
Contents
• NONO findings in the midbrain
• Efferent system
• Supranuclear
• Nuclear
• Internuclear – Vertical one‐and‐a‐half
• Afferent system
• Light‐near dissociation, RAPD
• Pretectal syndrome
Vertical gaze palsy
• Supranuclear?
• Nuclear?
• Infranuclear?
Pupil + Eyelid Approaching patients with vertical gaze palsies (midbrain lesion)
I. It is crucial to test not just range of motion, but also to determine whether there are selective defects of saccades, smooth pursuit, vestibular, or vergence eye movements
II. Test the tVOR, noting whether quick phases of nystagmus occur in both directions as the patient’s head rolls from side to side III. Ocular alignment, looking for oculomotor or trochlear palsy and the
OTR including skew deviation
IV. Look for abnormalities of the eyelids and pupils, which commonly accompnay vertical gaze disorders
3 rd NERVE PALSY
• Oculomotor nucleus
• Limited range of motion
• not overcome with vertical VOR
• Consistent vertical gaze palsy while saccades, smooth pursuit, Optokinetic, and VVOR
• MR
4 th NERVE PALSY
관계ID가 rId2인 이미지 부분을 파일에서 찾을 수 없습니다.
Trochlear nerve
• Trochlear nucleus
• smallest cranial nerve nuclei
• area=0.6 mm2, number of nerve cells = 3400
• The only cranial nerve that arises from the back of the brainstem
• Most slender cranial nerve with 1 mm thickness
• It follows the longest course within the skull of any of the cranial nerves (75 mm)
• “Trauma nerve”
lateral
medial rostral
caudal
Nuclear vs infra-nuclear III
• Weber’s syndrome
‐ midbrain basis
‐ oculomotor nerve fascicles; ipsilateral III palsy
‐cerebral peduncle; contralateral hemiparesis
• Claude’s syndrome
‐ oculomotor nerve fascicles; ipsilateral III palsy
‐ red nucleus, sup cbll peduncle; contralateral ataxia
• Benedikt’s syndrome
‐ oculomotor nerve fascicles; ipsilateral III palsy
‐ cerebral peduncle; contralateral hemiparesis
‐red nu. SN, SCD; contralateral ataxia, tremor, & involuntary movement
Vascular syndromes of the midbrain Wernekink syndrome
• Decussation of SCP (brachium conjunctivum) – prominent ataxia
Central segment of IV Syndromes of IV palsy
• Nuclear
• Most often d/t stroke, less often neoplasm, demyelinative or trauma.
• Almost never isolated
• Fascicular
• Rare, may get contralateral Horner’s syndrome; trauma (especially near anterior medullary velum) may cause bilateral SO palsy
관계ID가 rId2인 이미지 부분을 파일에서 찾을 수 없습니다.
Central IV palsy
• Isolated left SO palsy following dorsal midbrain hemorrhage
(Lee SU, J Clin Neurol, 2018)
관계ID가 rId2인 이미지 부분을 파일에서 찾을 수 없습니다.
Central IV palsy
(Lee SH, Clin Neurol Neurosurg, 2010)
INTERNUCLEAR
관계ID가 rId2인 이미지 부분을 파일에서 찾을 수 없습니다.
SO palsy vs. skew deviation
SUPRANUCLEAR PALSY
In ER In OPD
Alternating skew deviation
• Amplitude and the side of the hypertropia vary as a function of horizontal position of the eyes in the orbit
INTERNUCLEAR
• Convergence – preserved by lidocaine injection in monkeys
• Convergence – impaired in 40%
of patients with INO from midbrain infarction
(Gamlin PDR, J Neurophysiol, 1989) (Kim JS, Neurology, 2014)
Internuclear: MLF syndrome
(Lee SU, J Neurol, 2016)
• MLF + pedunculopontine nucleus lesion
• INO + contralesional truncal ataxia mostly indicates MLF lesion at the level of pontomesencephalic junction
Internuclear: Vertical one-and-a-half
(Sato K, Neurol Clin Neurosci, 2018)
Pretectal syndrome
(aka Parinaud syndrome)Neural substrates for vertical eye movements
Neural substrates for vertical eye movements
• Posterior commissural fibers (PC)
• Interstitial nucleus of Cajal (INC)
• Rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF)
• Oculomotor nucleus
riMLF
• No spontaneous nystagmus
• Impaired convergence
• Impaired t‐VOR (no clockwise nystagmus while right head tilt)
INC
PC Supranuclear palsy – vertical EOM palsy
Intermittent diplopia During fixation on near
targets and horizontal smooth pursuit Released after a blink Associated with miosis
Near target
Near target removed
‐> Convergence spasm
Convergence—retraction nystagmus Collier’s sign
• Bilateral, sometime asymmetric
• Damage to the PC levator inhibitory fibers in M‐group
• Mostly a/w upward gaze palsy
• No lid lag during downward gaze (TAO: lid lag (+))
Convergence abnormalities
Convergence spasm
(aka pseudo-abducens palsy)(Ghasemi M, Clin Imaging, 2017)
• Lesions involving convergence pathway near the midbrain‐diencephalic region
• Frequently a/w upward gaze palsy, convergence‐retraction nystagmus
Convergence abnormalities
• Convergence spasm
• Convergence insufficiency
• Divergence spasm
• Divergence insufficiency
Ocular alignment Mostly during
Eso- At near
Exo- At near
Exo- At far
Eso- At far
Light-near dissociation
SUMMARY
Approaching patients with vertical gaze palsies
I. It is crucial to test not just range of motion, but also to determine whether there are selective defects of saccades, smooth pursuit, vestibular, or vergence eye movements
II. Test the tVOR, noting whether quick phases of nystagmus occur in both directions as the patient’s head rolls from side to side III. Ocular alignment, looking for oculomotor or trochlear palsy and the
OTR including skew deviation
IV. Look for abnormalities of the eyelids and pupils, which commonly accompnay vertical gaze disorders
Approaching patients with vertical gaze palsies
I. It is crucial to test not just range of motion, but also to determine whether there are selective defects of saccades, smooth pursuit, vestibular, or vergence eye movements
II. Test the tVOR, noting whether quick phases of nystagmus occur in both directions as the patient’s head rolls from side to side III. Ocular alignment, looking for oculomotor or trochlear palsy and the
OTR including skew deviation
IV. Look for abnormalities of the eyelids and pupils, which commonly accompnay vertical gaze disorders
Approaching patients with vertical gaze palsies
I. It is crucial to test not just range of motion, but also to determine whether there are selective defects of saccades, smooth pursuit, vestibular, or vergence eye movements
II. Test the tVOR, noting whether quick phases of nystagmus occur in both directions as the patient’s head rolls from side to side III. Ocular alignment, looking for oculomotor or trochlear palsy and the
OTR including skew deviation
IV. Look for abnormalities of the eyelids and pupils, which commonly accompnay vertical gaze disorders
Approaching patients with vertical gaze palsies
I. It is crucial to test not just range of motion, but also to determine whether there are selective defects of saccades, smooth pursuit, vestibular, or vergence eye movements
II. Test the tVOR, noting whether quick phases of nystagmus occur in both directions as the patient’s head rolls from side to side III. Ocular alignment, looking for oculomotor or trochlear palsy and the
OTR including skew deviation
IV. Look for abnormalities of the eyelids and pupils, which commonly accompany vertical gaze disorders
Questions or comments?
뇌는 하늘보다 넓어라 옆으로 펼치면 그 안에 하늘이 쉬 들어오고 그 옆에 당신마저 안긴다
뇌는 바다보다 깊어라 깊이 담그면 아주 푸르게 그 속에 바다가 다 물통 속 스펀지처럼 담긴다
뇌는 신처럼 무거워라 무게를 나란히 달면 다르다 해도 음절과 음성 차이 정도나 될까
E. Dickinson (1830~1886)
