1. Neurological Department, Klinikum Worms, Germany
The spectrum of ocular motor abnormalities as the only clinical sign of brain stem lesions
Frank Thömke
Neurological Department, Klinikum Worms, Germany
The widespread use of magnetic resonance imaging has shown an increasing variety of monosymptomatic
brain stem lesions, mainly infarcts. Among them, ocular motor abnormalities represent an important
subgroup. This paper reviews the spectrum of such abnormalities.
Possible ocular motor abnormalities as the only clinical signs of brainstem lesions
isolated 3rd nerve palsies
due to midbrain infarcts
isolated superior rectus palsy
due to a midbrain infarct
Kwon et al. Arch Neurol 2003
isolated inferior rectus palsy
due to a midbrain infarct
Lee & Kim Neurology 2006
isolated superior oblique palsy
due to a midbrain infarct
Walsh Arch Neurol 2010
isolated painful mydriasis
due to a midbrain abscess
 3rd nerve palsy
„superior branch“ palsy
„inferior branch“ palsy
rectus superior palsy
rectus inferior palsy
rectus medialis palsy
unilateral mydriasis
unilateral mydriasis + ptosis
 4th nerve palsy
 6th nerve palsy
 vertical gaze palsy
 crossed vertial gaze palsy
 monocular elevation paresis
 horizontal gaze palsy
 imternuclear ophthalmoplegia
 1½-syndrome
 8½-syndrome
 skew deviation
 ocular tilt rection
 horizontal-rotatory nystagmus
 upbeat nystagmus
 Horner‘s syndrome
INC
riMLF
riMLF
III IV
isolated vertical gaze palsy
due to a midbrain infarct
isolated monocular elevation palsy
due to a midbrain infarct
Thömke & Hopf Brain 1992 VI
isolated horizontal gaze palsy
due to a pontine infarct
isolated INO
due to a pontine infarct
Nucl. Intercalatus
(Staderini)
Hassler Neurology 1967
isolated 1½ - syndrome
due to a pontine infarct
isolated 8½ - syndrome
(1½-syndrome + 7th nerve palsy)
due to a pontine infarct
isolated pseudoneuritis vestibularis
due to a medullary infarct
isolated pseudoneuritis vestibularis
due to a medullary demyelination
upbeat nystagmus + vertigo
due to a medullary demyelination
isolated 6th nerve palsy
due to a Gd-enhancing
pontine demyelination
isolated 6th nerve palsy
due to a pontine infarct
Except where indicated all MRI-images are with kind permission of W. Müller-Forell and P. Stoeter, Institue for Neuroradiology, University Medical Center Mainz, Germany
There are 4 main groups of brainstem lesions, which cause isolated ocular motor abnormalities:
 Lesions of infranuclear ocular motor nerve segments cause 3rd, 4th and 6th nerve palsies.
 Lesions affecting nuclei related to eye movements (3rd and 6th nerve nucleus, riMLF, INC, nucleus
intercalatus Staderini) are followed by horizontal and vertical gaze palsies or upbeat nystagmus.
 Lesions interrupting internuclear connections may cause internuclear ophthalmoplegia, monocular
elevation paresis, skew deviation, ocular tilt reaction or upbeat nystagmus.
 Combined lesions of nuclear and internuclear or infranuclear structures are the anatomical basis of
1½-syndrome, 8½-syndrome, or horizontal gaze palsy with facial palsy.
The clinical significance of these disorders is not known.