1. Is this patient’s facial weakness of the lower motor neuron or upper motor neuron type?
Upper motor neuron
2. Indicate the specific structures involved by the pathologic process for each of the signs or symptoms listed below.
a. Right UMN facial palsy and right hemiparesis: Left corticospinal and
corticonuclear tracts, at or above the lower third of the pons.
b. Inability to move either eye past midline when attempting to look horizontally to the left: Left pontine horizontal gaze center (PPRF + abducent nucleus).
c. Inability to move the left eye past midline when looking horizontally to the right: Left MLF.
3. Indicate the precise anatomical location of the lesion, including the side of involvement.
Left basilar part of the pons, extending into the medial tegmentum, at the level of the lower third of the pons (see Slide #1).
4. This patient’s eye movement findings represent a classic neuro-ophthalmologic syndrome. What is the name of this syndrome? Name the components of this syndrome.
One-and-a-half syndrome.
1. Left horizontal gaze palsy.
2. Left internuclear ophthalmoplegia (INO).
5. In general, what type of pathologic process is involved in this case?
Vascular – Involving the paramedian pontine branches of the lower basilar artery
6. What diagnostic procedure(s) would you undertake at this point?
References:
1. Fisher CM. J Neurol Neurosurg Psychiatry 1967;30:383-392.
2. Wall M, Wray SH. Neurology 1983;33:971-980.
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