17. Masseter reflex abnormalities with meso-diencephalic lesions

Abstract

different papers and some eponyms used to characterize a certain neurological state differ from the original description. Except for Wallenberg‘s syndrome, classical brainstem syndromes are rarely seen in clinical practice. Lacunar brainstem syndromes are the consequence of infarcts, which involve long tracts and spare intra-axial cranial nerve segments. This group includes pure motor or pure sensory stroke, dysarthriaclumsy hand syndrome, or ataxic hemiparesis. Such infarcts may also cause body lateropulsion with or without limb ataxia, internuclear ophthalmoplgia, skew-torsion sign, or ocular tilt reaction. Small deep infarcts, which solely affect certain nuclei, may be followed by horizontal or vertical gaze palsies, upbeat nystagmus, isolated facial palsy, pseudoneuritis vestibularis, or isolated vomiting. Lacunar syndromes are more frequent than classical brainstem syndromes. Isolated cranial nerve dysfunctions are due to infarcts, which involve intra-axial cranial nerve segments and spare long tracts, and were reported for 3rd, 4th, 5th, 6th, 7th, or 8th nerves. This is the clinical manifestation of some percent of infarcts in the vertebrobasilar territory.