[Quantitative analysis of corneal subbasal nerve plexus with in vivo confocal laser scanning microscopy]. / Quantitative Analyse des subbasalen Nervenplexus der Kornea mittels in vivo konfokaler Laser-Scanning-Mikroskopie.

BACKGROUND: An analysis of the corneal subbasal nerve plexus (SNP) allows an evaluation of the peripheral neuropathy in cases of degenerative diseases. In order to study the SNP structures quantitatively the automatically calculated morphological and topological parameters are required. METHODS: In vivo confocal laser scanning microscopy (Heidelberg Retina Tomograph II/Rostock Cornea Module) was performed in healthy volunteers as well as patients with severe diabetic neuropathy. An adapted image processing algorithm was used to preprocess, segment and evaluate quantitatively the nerve fibers of the SNP. Data sets were analysed statistically. RESULTS: The developed algorithm allows an automated detection of SNP structures. Furthermore, it allows the collection of data based on morphological and topological parameters. The main parameters that show significant differences between healthy cornea and cases of diabetic neuropathy are nerve fibre density and length, number of branching, tortuosity and number of terminal and crossing points. All parameters of the measurements can be used isolated, combined or weighted for quantification of the SNP networks. CONCLUSION: The presented fully automated preprocessing eliminates a large number of motion-induced artefacts. The quality of the resulting pictures allows an automated quantification using characteristic measurements. This represents an in vivo, non-invasive technology analysing degenerative changes of SNP especially in the course of diabetes mellitus.

Lifetime mental disorders and suicidal behaviour in South Africa.

OBJECTIVE: There is relatively little data on the relationship between lifetime mental disorders and suicidal behaviour in low and middle income countries. This study examines the relationship between lifetime mental disorders, and subsequent suicide ideation, plans, and suicide attempts in South Africa. METHOD: A national survey of 4185 South African adults was conducted using the World Health Organization Composite International Diagnostic Interview (CIDI) to generate psychiatric diagnoses and suicidal behaviour. Bivariate, multivariate and discrete-time survival analyses were employed to investigate the associations between mental disorders and subsequent suicide ideation, plans, and attempts. RESULTS: Sixty-one percent of people who seriously considered killing themselves at some point in their lifetime reported having a prior DSM-IV disorder. Mental disorders predict the onset of suicidal ideation, but have weaker effects in predicting suicide plans or attempts. After controlling for comorbid mental disorders, PTSD was the strongest predictor of suicidal ideation and attempts. There is a relationship between number of mental disorders and suicidal behaviour, with comorbidity having significantly sub-additive effects. CONCLUSION: Consistent with data from the developed world, mental disorders are strong predictors of suicidal behaviour, and these associations are more often explained by the prediction of ideation, rather than the prediction of attempts amongst ideators. This suggests some universality of the relevant mechanisms underlying the genesis of suicidal thoughts, and the progression to suicide attempts.

Arrhythmias in infants and children with primary cardiac tumours.

Twenty-one patients, aged from 1 day to 16 years (median 8 months), with primary cardiac tumours, were studied with regard to the occurrence of arrhythmias. Standard electrocardiogram (ECG) was available in 20 cases and 24 h ambulatory ECG in 19; nine patients had prospective follow-up investigations (mean follow-up time 3.0 years). Standard ECG revealed preexcitation in two and arrhythmias in six patients. Ambulatory ECG disclosed seven patients with significant rhythm disturbances and in four of these, the arrhythmia was the symptom leading to the diagnosis of a cardiac tumour. Three patients were symptomatic from arrhythmia and two of them were successfully treated with antiarrhythmic agents. The remaining patient with recurrent life-threatening ventricular tachycardia underwent partial resection of a large left ventricular fibroma; no further episodes of ventricular tachycardia were observed postoperatively. Only one of the 15 patients with cardiac rhabdomyomas required antiarrhythmic therapy. None of the nine patients prospectively followed developed arrhythmias requiring therapy. The present data underline the fact that infants and children with cardiac tumours rarely need surgery because of arrhythmia resistant to medical treatment. As far as possible, conservative management is indicated in infants with suspected rhabdomyomas.

Cardiac involvement in tuberous sclerosis.

OBJECTIVE: To assess the incidence, importance, and history of cardiac involvement in infants and children with tuberous sclerosis. DESIGN: Prospective study; clinical examination, sector and Doppler echocardiography, standard and ambulatory electrocardiography. SETTING: A tertiary referral centre. PATIENTS: 21 patients with tuberous sclerosis aged 1 day to 16 years (mean 6.3 years); follow up investigations were available in 14 cases (10 retrospective, 4 prospective; mean follow up 4.3 years). RESULTS: Multiple cardiac rhabdomyomas in the right ventricle (11) and left ventricle (14) as well as in the right atrium (1) were present in 14/21 patients. Two of them had obstruction of the left ventricular inflow and outflow tract related to a tumour. In the remaining 7 patients, echocardiography was normal in 4 and equivocal in 3 cases. The standard electrocardiogram (n = 20) showed ventricular hypertrophy (2), ventricular pre-excitation (1), arrhythmias (2), and repolarisation disturbances (4) in 7/13 patients with rhabdomyomas but was normal in all patients with a normal or equivocal echocardiogram. The ambulatory electrocardiogram (n = 19) showed frequent premature atrial (2) and polymorphous ventricular (2) contractions. The polymorphous ventricular contractions coexisted with rhabdomyomas. No arrhythmias that needed medical treatment were found. Follow up investigations showed return to a normal standard electrocardiogram in 3 patients. Definite regression or complete disappearance of the tumour occurred in 6 infants. CONCLUSIONS: Cardiac rhabdomyomas, although often present in these patients with tuberous sclerosis, caused neither major arrhythmias nor haemodynamic obstruction except in the neonatal period. The indication for operation is limited to cases with life threatening obstruction or arrhythmias refractory to medical treatment.