Upbeat nystagmus due to a small pontine lesion: evidence for the existence of a crossing ventral tegmental tract.

We report a patient with an isolated large upbeat nystagmus (UBN) in the primary position of gaze. Eye movements were filmed and recorded using electro-oculography. The upward vestibulo-ocular reflex gain, evaluated by pitching the head forward, was markedly reduced compared to when pitching the head back. The lesion was a probable lacunar infarction located in the paramedian and posterior part of the basis pontis, at the upper pons level. This UBN case, with one of the smallest brainstem lesions reported so far, supports the existence in humans of the crossing ventral tegmental tract, described in the cat and transmitting excitatory upward vestibular signals to the third nerve nucleus. It is also suggested that the decussation of this tract lies at the same upper pons level as in the cat but in a slightly more ventral location, i.e. in the posterior basis pontis.

Plasma C-peptide levels and clinical remissions in recent-onset type I diabetic patients treated with cyclosporin A and insulin.

Remission from insulin dependency in insulin-treated recent-onset type I (insulin-dependent) diabetic patients can result from a partial recovery of insulin secretion, an improvement in tissue sensitivity to insulin, or both. The same hypothesis must be analyzed when remission occurs in cyclosporin A (CsA)-treated patients. In this study, plasma C-peptide levels were serially measured in the basal state and after stimulation in 219 recent-onset type I diabetic patients; 129 received CsA, and all patients were similarly monitored and insulin treated. The results were analyzed in view of the occurrence of remission. Remission was defined as good metabolic control in the absence of hypoglycemic treatment for greater than or equal to 1 mo. Remission occurred in 44% of the CsA-treated group and lasted for mean +/- SE 10.0 +/- 0.9 mo vs. 21.6% in the non-CsA-treated group with a duration of 4.4 +/- 0.8 mo. Plasma C-peptide levels were initially dramatically lower than normal in both groups in the basal and stimulated states. C-peptide levels increased significantly later, at 3 and 6 mo, in both groups. C-peptide values were proportional to the rates of remission in both groups. In the non-CsA-treated group, C-peptide levels later decreased, and these patients inexorably relapsed to insulin dependency. In contrast, in the CsA-treated group, the initial recovery in insulin secretory capacity was maintained over the 18-24 mo of the study. Furthermore, higher remission rates and longer-lasting remission were obtained in patients who reached higher C-peptide levels at the 3rd mo of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Cyclosporin increases the rate and length of remissions in insulin-dependent diabetes of recent onset. Results of a multicentre double-blind trial.

In a double-blind trial 122 patients aged 15-40 years with insulin-dependent diabetes of recent onset were randomly assigned to cyclosporin 7.5 mg/kg per day or placebo. At the sixth month 25.4% of the cyclosporin group and 18.6% of the placebo group were in complete remission (not a significant difference). Treatment was continued in those patients with complete or partial remission (insulin requirement less than 0.25 U/kg per day) and 106 patients were followed to nine months, at which stage 24.1% of the original cyclosporin group and 5.8% of the original placebo group were in complete remission (p less than 0.01). For those patients whose whole-blood trough cyclosporin levels in the first three months averaged 300 ng/ml or more, the rates of complete remission at six and nine months were 37.5% and 37%. The rates of partial remission were also higher in the cyclosporin group and at six months the rate of complete or partial remission was 46% in the whole cyclosporin group and 65.6% in those with an average blood level exceeding 300 ng/ml in the first three months, versus 28.8% in the placebo group. The principal side-effect of cyclosporin was a modest and reversible increase in plasma creatinine. These results indicate that cyclosporin promotes the remission of type I diabetes and suggest the need for new controlled protocols aimed at evaluating the length of the effect and selecting the best drug regimen.

[Induction of remissions of insulin-dependent diabetes by cyclosporin]. / Induction de rémissions du diabète insulino-dépendant par la cyclosporine.

The effect of cyclosporine was evaluated in a double blind placebo controlled trial in 122 recent onset insulin-dependent diabetics. A significantly higher incidence of complete remissions was observed in patients treated with cyclosporine than in those receiving placebo (respectively 24 and 5.8%). The effect was still more clear-cut in patients having presented the highest cyclosporine blood level (37%). These results which have been obtained with modest toxicity demonstrate that cyclosporine induces remission of insulin-dependent diabetes and prompt to set up new controlled trials to evaluate the duration of the effect obtained and the potential risks of the treatment.