The symposium is co-organised by The Ann Conroy Trust, in association with Aesculap Academia.
The Ann Conroy Trust is Registered Charity No: 1165808.
We provide Support, Education and Research for patients living with Chiari Malformation, Syringomyelia and associated conditions.
F25 Neurophysiological and neuroradiological correlates in patients with syringomyelia and Chiari malformation: a central motor conduction time along the phrenic nerve and fibre tracking study.
Ciaramitaro P, Massaro F, Ferraris M, Valentini CM, Cocito D.
The cortico-diaphragmatic pathway was investigated by means of transcranial magnetic stimulation (TMS) in cases of amyotrophic lateral sclerosis (ALS) without clinical signs of respiratory impairment and was found to be a sensitive measure to reveal sub-clinical diaphragmatic impairment This study aimed to: 1) investigate the central motor conduction time (CMCT) along the phrenic nerve in patients affected by syringomyelia, with or without Chiari Malformation (CM), in order to identify sub-clinical alterations of the phrenic pathway, and 2) to correlate the electrophysiological data to a Fibre Tracking (FT)-Diffusion Tensor Imaging (DTI) neuroradiological technique for evaluating cortico-spinal fibre loss.
100 patients (25 males, 75 females), average age 49±14 years, were selected and divided into three groups: 1)syringomyelia with Chiari malformation, 2) isolated syringomyelia and 3)isolated Chiari. TMS was performed in all patients by standard techniques. Electrophysiological parameters were statistically analysed and compared with 30 healthy subjects. DTI study was performed in 40 patients (altered/normal CMCT) and Fractional Anisotropy (FA) was calculated in three volumes of interest - whole cord, right and left hemi cord - at C2, C3, C4 spinal levels.
Pathological phrenic CMCT was observed in 27 patients (30% in subgroups syringomyelia + Chiari and isolated syringomyelia). FA values were significantly different at all levels, compared with healthy subjects (at C2 p<0.005; at C3 p<0.05, at C4 p<0.05) and compared with altered CMCT patients at C3 level (p<0.05), with a high correlation (76%).
CMCT along the phrenic nerve was a sensitive measure to identify alterations in voluntary respiratory pattern, before clinical presentation, in syringomyelia. Our results confirm the presence of an axonal damage underlying pathological CMCT.
Altered phrenic CMCT may be a good predictor of sub-clinical diaphragmatic impairment. The alterations found may be explained by cortico-spinal drive impairment and/or degeneration of the phrenic-related second motor neurons.