Utility of multimodal evoked potentials study in neurofibromatosis type 1 of childhood.

A group of 21 children affected by neurofibromatosis type 1 has been investigated with the aim of studying multimodal (visual, brainstem auditory, and somatosensory) evoked potentials and their correlations with neurologic, electroencephalographic, and cranial magnetic resonance imaging. In the present series, cranial magnetic resonance imaging and evoked potentials were the most frequently abnormal instrumental tests. In approximately two thirds of the cases at least one of the evoked potentials (particularly visual and auditory evoked potentials) was compromised, always without clinical signs of related sensory (visual, auditory, and somatosensory) pathway pathology and sometimes in the absence of magnetic resonance imaging signs of central nervous system involvement. This study indicates that in patients with neurofibromatosis type 1, multimodal evoked potentials are useful and should be part of the diagnostic protocol of encephalic lesions together with magnetic resonance imaging. The use of both methods could aid in early detection of central nervous system dysfunction in both the initial evaluation of disease and its follow-up.

Peripheral neuropathy in hepatitis-related mixed cryoglobulinemia: electrophysiologic follow-up study.

A retrospective study was performed on 27 patients with hepatitis C (HCV)-related mixed cryoglobulinemia (purpura, arthralgia, hepatitis, glomerulonephritis, peripheral neuropathy) to assess peripheral nerve involvement during follow-up of up to 8 years. All patients had the same degree of organ/system involvement initially and were clinically evaluated at least annually. All 27 patients received steroids; 15 also received recombinant interferon-alpha 2b (rIFN-alpha 2b). At first examination, neurological signs and electrodiagnostic findings consistent with peripheral neuropathy were found in 20 (74%) and in 24 (88.8%) patients, respectively. Neurological evaluation and electrodiagnostic data at 3 and 8 years revealed worsening of neuropathy, whereas the other manifestations of mixed cryoglobulinemia (MC) were stable. At the last examination, clinical and electrodiagnostic signs of neuropathy were found in 25 patients (92.5%), occurring in 1 of 3 patients with normal initial findings, and worsened in 8. A more severe neuropathy was observed in 3 (25%) of the patients treated with prednisone alone and in 6 (40%) of the patients additionally treated with rIFN-alpha 2b. Our data confirm that in patients with HCV-related MC, peripheral nerve involvement is frequent, is progressive, and does not seem to benefit by addition of rIFN-alpha 2b to steroid treatment.