Brain Stem Magnetic Resonance Imaging and Evoked Potential Studies of Symptomatic Multiple Sclerosis Patients

Abstract

In this study we evaluated the sensitivity of neuroradiological and neurophysi-ological tests for detecting brain stem (BS) lesions in multiple sclerosis patients, since the recent introduction of the gradient motion rephasing technique has markedly increased the image quality of magnetic resonance imaging (MRI). From 50 MS patients (33 women and 17 men; mean age 35.9 ± 8.3 years; mean duration of the disease 7.2 ± 4.1 years) with clinical signs of BS involvement, brain MRI, BS auditory evoked potentials (BAEPs), and left and right median somatosensory evoked potentials (mSEPs) were obtained. BS MRI lesions were detected in 41 patients (82%); in 14 cases they were located in the medulla oblongata, in 55 in the pons, and in 24 in the midbrain. Single lesions were present in 20 patients, while two or more BS lesions were demonstrated in 21 patients; 30 patients had at least one lesion located close to the inner or the outer cerebrospinal fluid border. BAEPs were abnormal in 19 of the 50 patients (38%), and BS components of mSEPs were abnormal in 15 of 46 (33%). With combined use of these neurophysiological techniques, BS abnormalities were revealed in 24 patients (48 %). Only 1 patient had neurophysiological BS abnormalities and normal MRI. Moreover, there was a good correlation (74%) between the clinical and MRI BS findings in the 23 patients with signs referable to focal neurological BS lesions. The concordances considering clinical and evoked potential reports were positive, but less marked. Our data demonstrate that a thin-slice MRI examination using the gradient motion rephasing technique is far more sensitive than BAEPs or mSEPs for detecting BS-demyelinating lesions.

Evaluation of brainstem involvement in multiple sclerosis

“…While correlation between symptoms and signs of a visual, motor or sensory system involvement and VEP, motor and somato sensory EP abnormalities, respectively, is good, brainstem auditory EPs (BAEPs) may be normal in 30-50% of MS patients with symptoms or signs of brainstem involvement [51,52]. Furthermore, the number of pathological EPs has a stronger correlation with EDSS than the T2 lesion load in patients with relapsing-remitting MS [53].…”

“…Although BAEPs may be normal in 30-50% of MS patients with symptoms or signs of brainstem involvement [51,52], one study on a relatively small number of patients showed that BAEP was able to localize lesions along the auditory pathways at a rate that was almost similar to that of MRI [60].…”

Comparison of MRI and electrophysiological studies for detecting brainstem lesions in traumatic brain injury

“…2,10,11 Some investigators have found a good correlation between the MRI and clinical findings, whereas the diagnostic yield of electrophysiological tests (BAEPs and median nerve evoked somatosensory potentials) was considered to be poor. 2 Others, using masseter reflex studies and electrooculography, found a diagnostic sensitivity of electrophysiological investigation superior to that of MRI. 10,11 The predominance of midbrain lesions over pontine lesions parallels the findings of Gentry et al 4 and our previous experience 12 in TBI.…”

Micturition disorders in multiple sclerosis patients: neurological, neurourodynamic and magnetic resonance findings

“…Furthermore, this group also showed significantly lower mean age and disease duration. MRI findings revealed that burden of lesion, number and location of hyperintensity signals derived from T2 weighted images (which probably correspond to demyelinating plaques) (Ormerod et ul., 1987;Paty et uf., 1988;Comi et al, 1993;Miller et a]., 1994), available from frontal cortex, subtentorial and supratentorial regions, are significantly lower in patients without urodynamic and urological symptoms (Fig. 2).…”