Predictive value of selected geriatric parameters for postoperative outcomes in older patients with rectal cancer - A multicenter cohort study.

INTRODUCTION: Older patients have a higher risk for complications after rectal cancer surgery. Although screening for geriatric impairments may improve risk prediction in this group, it has not been studied previously. METHODS: We retrospectively investigated patients ≥70 years with elective surgery for non-metastatic rectal cancer between 2014 and 2018 in nine Dutch hospitals. The predictive value of six geriatric parameters in combination with standard preoperative predictors was studied for postoperative complications, delirium, and length of stay (LOS) using logistic regression analyses. The geriatric parameters included the four VMS-questionnaire items pertaining to functional impairment, fall risk, delirium risk, and malnutrition, as well as mobility problems and polypharmacy. Standard predictors included age, sex, body mass index, American Society of Anesthesiologists (ASA)-classification, comorbidities, tumor stage, and neoadjuvant therapy. Changes in model performance were evaluated by comparing Area Under the Curve (AUC) of the regression models with and without geriatric parameters. RESULTS: We included 575 patients (median age 75 years; 32% female). None of the geriatric parameters improved risk prediction for complications or LOS. The addition of delirium risk to the standard preoperative prediction model improved model performance for predicting postoperative delirium (AUC 0.75 vs 0.65, p = 0.03). CONCLUSIONS: Geriatric parameters did not improve risk prediction for postoperative complications or LOS in older patients with rectal cancer. Delirium risk screening using the VMS-questionnaire improved risk prediction for delirium. Older patients undergoing rectal cancer surgery are a pre-selected group with few impairments. Geriatric screening may have additional value earlier in the care pathway before treatment decisions are made.

Bioavailability of rifampicin in Indonesian subjects: a comparison of different local drug manufacturers.

To examine the bioavailability of rifampicin formulations produced in Indonesia, we conducted a single-dose, double-blind, cross-over bioavailability study. Antituberculosis drugs from three Indonesian manufacturers and one international manufacturer were compared in 12 healthy Indonesian subjects. Out of three local manufacturers, two showed equal bioavailability compared to the reference standard, and one showed slightly lower bioavailability (ratio 0.86; 90% confidence interval 0.80-0.91) and substandard rifampicin content of drug preparations. Plasma rifampicin concentrations in this study were more than three-fold higher than concentrations recently found in tuberculosis patients in Indonesia, which suggests that unknown (disease-related) determinants may reduce the bioavailability of rifampicin formulations.

The existence of two sources in rolandic epilepsy: confirmation with high resolution EEG, MEG and fMRI.

In benign rolandic epilepsy seizure semiology suggests that the epileptic focus resides in the lower sensorimotor cortex. Previous studies involving dipole modeling based on 32 channel EEG have confirmed this localization. These studies have also suggested that two distinct dipole sources are required to adequately describe the typical interictal spikes. Since in benign epilepsy invasive validation is prohibited, this study tries to further establish these results using a multi-modal approach, involving 32 channel EEG, high resolution 84 channel EEG, 151 channel MEG and fMRI. From one patient interictal spikes were recorded and analyzed using the MUSIC algorithm in a realistic volume conductor model. In an fMRI experiment the same patient performed voluntary tongue movements, thus mimicking a typical seizure. Results show that EEC, MEG and fMRI localization converge on the same area in the lower part of the sensorimotor cortex, and that high resolution EEG clearly reveals two distinct sources, one in the post- and one in the pre-central cortex.

Dipole source analysis may differentiate benign focal epilepsy of childhood with occipital paroxysms from symptomatic occipital lobe epilepsy.

The aim of the study was to distinguish Benign Focal Epilepsy of Childhood with Occipital Paroxysms (BEOP) from its symptomatic counterpart on the basis of the location of the sources of the interictal EEG spikes. Patients were classified into two groups: idiopathic BEOP and symptomatic occipital lobe epilepsy. Source analysis of the averaged occipital spikes was performed using a homogeneously conducting sphere as the volume conductor model. Results showed a statistically significant difference in the eccentricity, i.e., the distance of the occipital spike focus from the centre of the head. The dipole sources of the occipital spikes in the BEOP group were found to be located more superficially than in the symptomatic group, corresponding in six of the nine cases with a source position estimated to be within the cortical layer just below the skull. The eccentricity of the symptomatic occipital spikes suggests a location deeper than the cortical layer. The results were validated in two patients from the symptomatic group. In one patient the estimated deeper dipole source location corresponded with a deeper location of spike activity observed during ECoG; in the other patient's ECoG, spike activity was observed superficially but over an extended area. The discrepancy between estimated and real location may be explained by the method of dipole source analysis used. It is concluded that the finding of a superficial dipole source location of the occipital spikes provides an indication for the diagnosis BEOP (sensitivity: 67%; specificity: 74%).

Seizure semiology of occipital lobe epilepsy in children.

PURPOSE: Occipital lobe epilepsy in children occurs as an idiopathic form, i.e., Benign Epilepsy with Occipital Paroxysms (BEOP), and a symptomatic form. This study attempted to determine whether seizure semiology could distinguish between the two forms. METHODS: Fifty children (34 boys, 16 girls) with clinical seizures and interictal EEGs presenting occipital spikes were included consecutively in the study. Seizure onset was between the ages of 2 months and 15 years. Epilepsy was considered symptomatic when psychomotor retardation and/or abnormalities at neurological and/or neuroradiological examination were found: 17 children were classified as idiopathic, and the remaining 33 children were classified as symptomatic. Seizure semiology was assessed by means of a structured interview of the children and their parents, using a detailed questionnaire. Seizure semiology was determined to comprise motor (versive or other movements of the eyes, versive movements of the head, (hemiconvulsions), visual, other signs (e.g. vomiting and headache), and impairment of consciousness. RESULTS: There were no statistically significant differences in seizure semiology between the two groups. CONCLUSIONS: Seizure semiology cannot distinguish between different forms of occipital lobe epilepsy: Further clinical examination, clinical neurophysiological investigations, and neuroimaging studies are needed for a correct classification.

Identical morphology of the rolandic spike-and-wave complex in different clinical entities.

The morphology of the rolandic spike, the trough between the rolandic spike and the following slow wave, and of the slow wave itself was quantitatively studied in 43 children, classified into five clinical groups: (a) functional with epilepsy benign focal epilepsy of childhood with centrotemporal spikes (BECT) with oropharyngeal seizures or (b) BECT with unilateral or generalized seizures or (c) functional without epilepsy, and (d) organic with or (e) without epilepsy. The morphologic features of the rolandic spike-and-wave complex were identical in the five clinical categories. Thus, a quantitative description of the rolandic spike-and-wave complex can be given that is valid for the 43 children of the present study, although they represent a heterogeneity of associated clinical syndromes. The rolandic spike appeared to be not a spike but a sharp wave with a mean duration of 88 ms. In contrast to the opinion of several investigators, the morphology of the rolandic spike does not provide a clue to its "epileptogenicity" or to the presence or absence of an organic cerebral lesion in the individual child. In clinical practice, additional information (background activity of the EEG, computed tomography (CT) scan, or magnetic resonance imaging (MRI) of the brain) is needed to determine the significance of rolandic spikes occurring in the EEG of a child with respect to the probability of a cerebral lesion and the prognosis in relation to epileptic seizures.

Dipole source analysis of rolandic spikes in benign rolandic epilepsy and other clinical syndromes.

Dipole source analysis of rolandic spike-and-wave complexes was performed in 48 children. The estimated source of the rolandic spike, of the trough between the spike and the following slow wave, and of the slow wave appeared to have the same position but had a small significant difference in orientation. Despite the heterogeneity of associated clinical syndromes, there were no clear differences between the clinical categories of patients regarding the localization and the orientation of the sources of the rolandic spike, trough and slow wave. The presence of a second source could explain the ascending phase of the rolandic spike in 19 children. This combination of two sources corresponded with the "double-spike phenomenon" that had been found previously by sequential brain mapping and which was associated with epilepsy. The preceding spike source and the source of the rolandic spike-and-wave complex were found to have the same position but a different orientation. A hypothetical explanation is proposed in which the presence of the rolandic spike-and-wave complex alone is insufficient to account for the clinical symptomatology. Both the preceding spike source and the source of the rolandic spike-and-wave complex, representing two separate, nearby but differently oriented populations of neurones in the inferior part of the rolandic cortex, is necessary for the development of epileptic manifestations.

Rolandic spikes in the inter-ictal EEG of children: contribution to diagnosis, classification and prognosis of epilepsy.

The clinical correlates of Rolandic spikes were studied in 47 children to determine the significance of this EEG finding to the diagnosis and classification of epilepsy. The children were classified into 'functional' and 'organic' groups, with and without epilepsy. Children with epilepsy were further subdivided into those with Rulandic and those with non-Rulandic seizures. In children without neurological abnormalities, the EEG finding of Rolandic spikes plays a decisive role in the diagnosis of an epileptic syndrome as benign focal epilepsy of childhood with centro-temporal spikes (BECT), a diagnosis with an excellent prognosis. Neurological and neuroradiological examinations of the 'functional' group revealed that the Rolandic spike may occur as a true 'functional' spike. The frequency of a family history of epilepsy among neurologically normal children with Rolandic spikes suggests, in addition to the inheritance of BECT and the EEG trait, the existence of a hereditary susceptibility to epilepsy.

Sequential EEG mapping may differentiate "epileptic" from "non-epileptic" rolandic spikes.

Sequential topographic mapping was performed to differentiate "epileptic" from "non-epileptic" rolandic spikes. Twenty-four children without any indication of organic brain lesion were divided into a group with epilepsy and a group without epilepsy. The group with epilepsy was subdivided into "classical BECT" (benign focal epilepsy of childhood with centro-temporal spikes) and "non-classical BECT." Sequential mapping of the rolandic spikes revealed two different topographic patterns: a pattern of stationary potential fields and a pattern of non-stationary potential fields. The topographic pattern of stationary potential fields was morphologically represented by a single spike-and-wave complex whereas that of non-stationary potential fields was morphologically represented by a "double" spike-and-wave complex. Among the non-stationary topographic patterns represented by a "double" spike, one specific sequence of changes of potential fields was found. This sequence started with a dipolar field, with the negative pole in the frontal region and the positive pole in the centro-temporal region, morphologically represented by the small first spike of the "double" spike-and-wave complex. This dipolar field, changes to a unipolar or dipolar field, with a negative potential field in the centro-temporal region and, sometimes, a simultaneous positive potential field in the frontal region, morphologically represented by the prominent rolandic spike. This characteristic pattern was found to be significantly related to classical BECT.

Accurate matching of electromagnetic dipole data with CT and MR images.

Interpretation of EEG (electroencephalography) or MEG (magnetoencephalography) derived three-dimensional dipole localizations is hampered by poor visualization. This paper describes a method for combining dipole data with structural image data of the same patient. To ensure high precision this method utilizes external markers that are easy to apply. These markers can achieve subslice accuracy and can even be used to pinpoint reference points outside the scanned volume. Accurate matching is thus provided even in standard imaging protocols employing thick slices and/or large interslice gaps. The results of the matching method are presented in 2D and 3D visualizations. The hybrid images facilitate the interpretation of dipole localizations with respect to the patient's anatomy.