Influence of the stimulation frequency on the morphology of auditory evoked potentials in multiple sclerosis

The Rate-linked modifications observed in the Auditory Brainstem Responses (A.B.R.) in normal subjects are now well known. On the other hand they are a subject of controversy among groups studying multiple sclerosis (M.S.). 49 patients were observed in parallel studies in Milan and Creteil. The A.B.R. obtained for slow stimulus rates (11-21 Hz) were compared to fast ones (51 Hz). The A.B.R. were not significantly modified in 32% of the cases (deterioration: 21%, improvement: 11%). The variations don't seem to depend on the kind of curves involved. This phenomena can be explained by a frequency linked block of conduction of the pathological fibres, either partial or total. These data seem to be specific to demyelinating diseases. A research project is being conducted to study their specificity

Ipsilateral masking of auditory evoked potentials: a method of studying multiple sclerosis

20 normal subjects and 39 patients with multiple sclerosis were the control and the test groups. Auditory brainstem potentials to 60 dB nHL, 11/s clicks, were recorded under ipsilateral broad-band noise masking at S/N ratio of + 60 dB (unmasked condition), + 20 dB, + 10 dB and 0 dB. In the control group the ABP were absent only in 1 subject at S/N = 0 dB. In the group of 16/39 patients with definite multiple sclerosis, 11 had no ABP at S/N = 0 dB, 6 at S/N = + 10 dB and 5 at S/N = + 20 dB. The ABP waveform per se, in the same subjects, was abnormal in 7 and doubtful in 5. These results are discussed in terms of sensitivity, specificity and efficiency of the test to be applied. The best predictive value is achieved by combining a strict morphological criterion with the results of the ipsilateral masking. Moreover, the ipsilateral masking test positive findings are equally distributed in the group of patients with and without signs of neurological involvement of the brainstem

Efficacy and tolerance of intranasal insulin administered during 4 months in severely hyperglycaemic Type 2 diabetic patients with oral drug failure: a cross-over study

Aims: We have evaluated the local tolerance and the metabolic efficacy of a lyophilized nasal insulin preparation in 10 severely hyperglycaemic Type 2 diabetic patients.Methods: The study included two 4-month randomized periods: (A) three preprandial doses of nasal insulin secondarily combined with one evening subcutaneous NPH if the desired glycaemic control was not achieved; (B) two NPH injections daily. We assessed: (i) diabetes control on monthly HbA1c levels and occurrence of hypoglycaemic events; (ii) local tolerance on clinical symptoms, rhinoscopy, nasal muco-ciliary clearance and nasal biopsies; (iii) insulin absorption at months 0 and 4.Results: One patient was withdrawn because of cough and dizziness after each nasal application. HbA1c was not significantly different at month 4 (9.4 +/- 0.5% vs. 8.8 +/- 0.2%, A vs. B). Blood glucose control remained only fair in the majority of our patients. Nasal insulin was able to replace the daytime fraction of the subcutaneous insulin with a 18% efficacy. Side-effects included transient nasal hyperactivity (pruritus, sneezing and rhinorrhoea) and chronic persistence of nasal crusts. Plasma insulin profiles were not significantly different between months 0 and 4.Conclusions: The utilization of nasal insulin (with or without NPH) was associated with similar diabetes control compared with NPH twice daily. Nasal insulin alone was able to achieve an adequate glycaemic control in three of the 10 patients

The classification of frontal sinus pneumatization patterns by CT-based volumetry

We aimed to define the classification of frontal sinus pneumatization patterns according to three-dimensional volume measurements