[The conduction of nerve impulses through MRIT2 hyperintense areas of patients with multiple sclerosis]

Normal nerve impulse conduction through pathological areas has been documented but is believed to be rare in Multiple Sclerosis (MS). We present two patients with clinically definite Multiple Sclerosis, Poser's type 1a, in whom evoked potentials (EP) and magnetic resonance imaging (MRI) were performed for diagnostic purposes. The first patient had normal brainstem auditory evoked potentials (BAER) and normal somatosensory evoked potentials (SEP) despite a large unilateral midbrain lesion on MRI. The second patient had normal SEP and an extensive lesion in the cervical spinal cord. These findings demonstrate that normal transmission can occur through hyperintense areas, and the rise the problem of nature of the lesions in Multiple Sclerosis.