Premium
Medullary infarcts may cause ipsilateral masseter reflex abnormalities
Author(s) -
Thömke Frank,
Marx Jürgen J.,
Cruccu Giorgio,
Stoeter Peter,
Hopf Hanns C.
Publication year - 2007
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.20829
Subject(s) - medicine , brainstem , medullary cavity , reflex , anatomy , magnetic resonance imaging , hypoglossal nerve , masseter muscle , motor nerve , pathology , tongue , anesthesia , radiology
Abstract There is a suprasegmental influence on the masseter reflex (MassR) in animals, which is mediated via the fifth nerve spinal nucleus (5SpN). Corresponding data in humans are lacking. Out of 268 prospectively recruited patients with clinical signs of acute brainstem infarctions, we identified 38 with magnetic resonance imaging (MRI)–documented unilateral infarcts caudal to the levels of the fifth nerve motor and main sensory nuclei. All had biplanar T2‐ and echo planar diffusion‐weighted MRI and MassR testing. Five patients (13%) had ipsilateral MassR abnormalities. In all, the infarcts involved the region of the 5SpN. Patients with medullary infarcts involving the region of the 5SpN may thus have ipsilateral MassR abnormalities. This possibly represents an interruption of an excitatory projection mediated via the 5SpN to masseter motoneurons in the fifth nerve motor nucleus. MassR abnormalities with medullary lesions restrict the topodiagnostic value of the MassR. Muscle Nerve, 2007