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Superior oblique myokymia: Magnetic resonance imaging support for the neurovascular compression hypothesis
Author(s) -
Yousry Indra,
Dieterich Marianne,
Naidich Thomas P.,
Schmid Urs D.,
Yousry Tarek A.
Publication year - 2002
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.10118
Subject(s) - neurovascular bundle , magnetic resonance imaging , trochlear nerve , microvascular decompression , medicine , hemifacial spasm , anatomy , magnetic resonance angiography , trigeminal neuralgia , radiology , surgery , pathology , facial nerve , palsy , alternative medicine
Abstract Superior oblique myokymia is a rare movement disorder thought to be caused by vascular compression of the trochlear nerve. Direct display of such neurovascular compression by magnetic resonance imaging has been lacking. The goal of this study was to assess the presence of neurovascular contacts in patients with superior oblique myokymia, using a specific magnetic resonance imaging protocol. A total of 6 patients suffering from right superior oblique myokymia underwent detailed neuro‐ophthalmological examination, which showed tonic or phasic eye movement. All patients underwent magnetic resonance imaging, using a magnetic resonance imaging Fourier transform constructive interference in steady‐state sequence in combination with magnetic resonance imaging time of flight magnetic resonance arteriography both before and after the administration of Gd‐DTPA. With this protocol, the trochlear nerve could be visualized on 11 of 12 sides (92%). Arterial contact was detected at the root exit zone of the symptomatic right trochlear nerve in all 6 patients (100%). No arterial contact was identified at the root exit zone of the asymptomatic left trochlear nerve in any of the 5 left nerves visualized. In conclusion, superior oblique myokymia can result from neurovascular contact at the root exit zone of trochlear nerve, and therefore should be considered among the neurovascular compression syndromes.