Bell's palsy: what is the prognostic value of measurements of signal intensity increases with contrast enhancement on MRI?

Our objective was to assess the prognostic value of measurements of the degree of contrast enhancement of the intratemporal segments of the facial nerve. We prospectively obtained MRI, slice thickness <1 mm of 20 patients with a facial palsy on the first day of inpatient treatment, and measured contrast enhancement of the nerve. The data were compared with compound muscle action potential (CMAP) measurements and the clinical course. Analysis of the initial enabled differentiation of three patients whose palsy was to show no improvement from 17 whose palsy was to resolve as expected. No patient with a poor outcome showed lesser increase in signal in the internal auditory canal, pars tympanica and pars mastoidea than patients who fully recovered. In no patient who had been diagnosed on the basis of the initial MRI as having a "normal" palsy was the amplitude of the (CMAP) reduced to less than 20% that of the normal side. Measurement of contrast enhancement was thus shown to be a prognostic indicator and may provide a basis for a differential treatment of facial palsy.

[The prognostic value of quantified MRI at an early stage of Bell's palsy]. / Der prognostische Wert der dynamischen, kontrastmittelverstärkten Region-of-interest-MRT in der Akutphase der idiopathischen Fazialisparese.

OBJECTIVE: The aim of the study was to assess whether MRI has a prognostic value at an early stage of Bell's palsy. MATERIAL AND METHODS: Prospective, blinded study on 30 patients suffering from Bell's palsy, who came to hospital until the sixth day of illness, to receive high doses steroid therapy. MRI was done on the first day of inpatient treatment as a gradient-echo-sequence with a slice thickness of 0.7 mm before and after i. v. administration of 0.1 mmol GdDTPA/kg weight. The signal intensity increase was evaluated quantitatively by region on interest (ROI). The results were compared to the clinical outcome and the results of electrophysiology. RESULTS: The examinations of all patients could be evaluated. The 3 patients who developed a chronic facial paralysis were detected by MRI on the first day of inpatient treatment. The patients, who showed MR signs for an unfavorable course, had a highly significant pathologic compound muscle action potential (CMAP) as a result of the electrophysiologic measurement. Rather than using complex measurement procedures it is possible to obtain reliable prognostic information from just one measurement within the Internal auditory canal before and after i. v. administration of contrast. CONCLUSION: MRI has a prognostic value at an early stage of the illness. In the clinical setting this measurement is easy to perform, so that it is possible to obtain prognostic information at a stage when causal treatment is still possible.

Electrophysiological analysis of expectancy: P3 in informed guessing.

18 healthy subjects had to guess, which of two nonequiprobable events would occur next. Each trial was preceded by a cue which increased the probability of the corresponding event as compared to its global probability. Event-related potentials (ERPs) were recorded and then classified according to global probability of events, their relation to the preceeding cue (valid versus invalid cues) and to subject's prediction (predicted versus nonpredicted). Two late positive waves (P350 and P550) with parietal maxima were distinguished. Both waves had larger amplitudes in response to improbable events than to highly-probably events. Similarly, both had larger amplitudes following invalid cues than following valid cues, and this difference was larger in those subjects who tended to follow the cue than in those who tended to reject it. No difference in terms of ERP component amplitudes was found between predicted and unpredicted events; however, the latency of the P350 peak was longer following unpredicted events. Taken together with data of the literature, the present results indicate that ERP allow us to distinguish between two meanings of the word "expectancy": (1) the rule-related expectancy as cognitive estimation of the likelihood or "representativeness" of an event (based on grasping event contingencies), and (2) the goal-related expectancy manifested in the subject's overt behavior. Only the former "expectancy" affects the amplitude of the late positive wave ("P3"), while the latter does not.

Supplementary motor area in spatial coordination of bilateral movements: a new aspect to 'the SMA debate'?

To test whether the supplementary motor area's (SMA) role is confined to determining the 'temporal' but not the 'spatial' properties of a movement (H.H. Kornhuber et al., in: W.A. Hershberger (Ed.), Volitional Action, Elsevier, Amsterdam, 1989, pp. 107-168), movement-related scalp-recorded negative DC potential shifts were recorded in bilateral movements requiring complex spatial coordination. In such bilateral continuous rotation movements, the effect of the rotation sense (symmetrical vs. antisymmetrical), i.e. the direction in which an arm or a finger rotated in relation to the other, heavily affected DC shifts over the frontocentral midline. Antisymmetrical rotation of upper limb segments was associated with higher negative DC shifts than symmetrical rotation was. This was true for rotations in the sagittal plane, irrespective of whether the rotation involved predominantly proximal muscles (by a rotation predominantly in the shoulder) or only distal muscles (by a rotation in the metacarpo-phalangeal joint of the index finger). If these negative cortical DC-shifts over the frontocentral midline relate to activity of mesial frontocentral structures including the SMA, then the present results suggest that there is a role for these cerebral areas in spatial coordination of bilateral movements. Surprisingly, this was not the case for similar finger movements performed in the frontal plane. The results of the present study and particularly the considering of some fundamentals of theoretical physics and of Popper's philosophy of science, made us revise our assumption motivating the present study, that time and space would represent two orthogonal factors of a movement and that the contributions of a particular cerebral motor area (such as the SMA) to 'spatial parameters' versus 'temporal parameters' of a movement can thus be teased apart.

Unimanual motor learning impaired by frontomedial and insular lesions in man.

We correlated impaired unimanual motor learning with the lesion site in 53 patients with chronic lesions predominantly of the frontal lobe. The lesions were assessed using computed tomography (CT), then transferred to standard templates of nine slices parallel to the canthomeatal plane and digitized with a raster matrix of 3 mm by 3 mm width. The learning task was to track a moving target on a computer screen with a dot guided by the preferred hand, while the horizontal coupling between hand movement and screen was inverted. The mean tracking error was recorded over eight successive trials of 80s duration. If the mean error of the last three trials was not lower than that of the first three trials, impaired motor learning was assumed. We correlated performance and lesion with a contingency table analysis for each raster element. Impaired motor learning was associated with a lesion within the supplementary motor area and adjacent anterior cingulate, and within the anterior insular region. Our results indicate that these regions are critical for motor learning and functional plasticity in man. Our data support activation patterns obtained with positron emission tomography.

Individual differences in slow brain potentials in a guessing task.

18 healthy right-handed subjects had to predict one of two random non-equiprobable events by pressing one of two buttons with the right index finger. Each trial was preceded by a cue that increased the probability of the corresponding event in comparison to its overall probability. The Bereitschaftspotential (BP) before an action and the stimulus-preceding negativity (SPN) between the action and the event presentation were recorded. The subjects were subdivided into groups according to their tendency to follow the cue or to reject it. Cue rejection provided in the present situation a larger final gain than cue acceptance. Those subjects who used the former strategy were characterized by a local BP increase over the right parietal cortex, when a low-probable cue was presented. Their SPN amplitude was relatively small, but it increased substantially after a low-probable cue. Subjects who tended to follow the cue had a very large BP amplitude over the projection area and at vertex. Their SPN was overall large, regardless of condition. Peculiarities of the potentials recorded in these subjects are thought to relate to their desire to minimize errors.

[The significance of quantitative computerized tomography in the long-term prognosis of ischemic stroke]. / Die Bedeutung der quantitativen Computertomographie für die Langzeitprognose von ischämischen Grosshirninsulten.

The courses of 118 patients who had suffered a supratentorial ischaemic infarction were observed over a mean follow-up period of 4 years. One goal of this study was to assess the prognostic value of quantitative cranial computerized tomography (CT). The infarct volume was determined using CT and expressed quantitatively as a percentage of the total brain volume. The infarct volume correlated negatively with the global outcome as estimated by the Barthel Index. It correlated positively with the occurrence of psychiatric alterations, disturbances of consciousness or alterations in the EEG. Nicotine, alcohol consumption and hyperuricaemia were the most frequent risk factors identified for men, while for women, especially those over 60, cardiac diseases were the most relevant risk factors. In looking only at the older patients, age, psychiatric alterations and cardiac disease at the time of the stroke were unfavourable prognostic factors. CT lesions in the basal ganglia were also unfavourable prognostic factors. Infarcts in the posterior cerebral artery region were seen as prognostically favourable. During the 4-year follow-up period, the reinfarction rate was 26%. Nearly 50% of the total patient population died. This group was significantly older, had more psychiatric alterations as well as multiple infarct areas in CT.

A technique for diagnosing the individual patterns of innervation of the trapezius muscle prior to neck dissection.

Based on the techniques of regional anaesthesia, a method for simulating the effects of radical neck dissection on the innervation of the trapezius muscle by selectively and reversibly blocking the accessory nerve and its superficial cervical anastomoses, was developed and tested on 40 patients who were due to undergo radical neck dissection. Action potentials of the three portions of the muscle were recorded after this blockade as well as after radical neck dissection, and compared. It was found that the electromyograms were congruent in 92.5% of the cases. Four patterns of innervation were demonstrated, ranging from complete substitution of the resected or blocked nerves to a remaining muscle activity of less than 20% after blockade or radical neck dissection.

Anticholinergic influences of biperidene on the EEG effects of haloperidol.

15 normal volunteers demonstrated after 14 days of haloperidol (HA) medication (3 mg/day) a higher mean power density (mpd) in all frequency bands of the EEG power spectra combined with a higher theta and a lower alpha center frequency (cf). After further 7 days of HA medication together with the additionally applied anticholinergic biperidene (BI) (6 mg/day) the HA effects were antagonized especially in the theta cf and the alpha mpd. The higher delta and theta mpd were not antagonized. The EEG spectra of the pre- and posttreatment condition did not differ. There was a significant effect of HA on the "Adjective Mood Scale" and on the "Complaint List", which disappeared during the additional BI medication. The reaction times were prolonged with HA and decreased with BI. Blocked dopaminergic impulses on the cholinergic EEG mechanisms possibly produce higher amplitudes during HA medication. Schizophrenic patients treated with neuroleptic drugs showed similar EEG spectra in previous studies during rest but not during motor activation.

Endogenous event-related brain potentials and psychometric performance in children at risk for schizophrenia.

Two independent groups of high-risk children for schizophrenia and their matched control children were submitted to the following experiments: an auditory oddball paradigm registrating late event-related potentials (ERPs) and a psychometric test battery including the assessment of Wechsler Intelligence Scales, reaction times (after regular and irregular preparatory intervals), and the d2-attention test. The study was intended to clarify whether long-latency ERPs and the selected psychometric tests would contribute to reliably differentiating between these groups. The results showed significantly prolonged latencies of the P3 component of the ERPs to rare, task-relevant target stimuli in both high-risk groups compared with the controls. Similarly, the N2 latencies were delayed in both groups. By contrast, ERP patterns to frequent, nontask-relevant stimuli were very similar, with no significant differences between high-risks and normals; nor did any ERP amplitudes show significant differences. The data are interpreted as a reflection of a subtle deficit in maintaining attention and a subsequent impairment of stimulus discrimination in high-risk children. This is consistent with the psychometric findings of higher error scores in target counts and d2-test, and significantly prolonged reaction times after regular preparatory intervals (PIs) in the high-risks. The findings may hint at a vulnerability for schizophrenia in high-risk children. Given the high prevalence of the attentional dysfunctions in both high-risk groups, however, it is hypothesized their presence does not necessarily imply an unequivocal manifestation of schizophrenia.

Stability of human blood serum aminoacids after storage at different pH and temperature conditions.

The stability of the aminoacids in human blood serum ultrafiltrates and in an aminoacid standard solution was investigated under different pH and storage conditions. At close to neutral pH values the aminoacid concentrations remained constant for at least 12 months at -50 degrees C (n = 6), except for lysine. With acid but particularly with alkaline conditions a time- and temperature-dependent decrease was observed for glutamine and asparagine with concomitant increases of glutamate and aspartate. Similar, but less prominent alterations were noted for the concentrations of methionine, glycine, tyrosine, histidine, arginine and ornithine. Almost independent of pH, there was an effect of temperature; after 24 h at 55 degrees C a significant increase of several per cent in a number of serum aminoacid concentrations was observed, presumably due to the hydrolysis of small proteins and peptides. For the purpose of aminoacid analysis it is recommended that samples be stored deproteinized, deep-frozen and at neutral pH.

[The main cause of diabetes (type II): "normal" alcohol drinking]. / Die Hauptursache von Diabetes (Typ II): der "normale" Alkoholkonsum.

In 1214 adult persons, the relationship between alcohol consumption, the "liver enzymes" and other metabolic parameters, including the serum lipids, were investigated. In 798 of the persons, glucose tolerance tests with measurement of plasma insulin were performed (young and old male and female adults, either volunteers or patients without liver-related diseases). There was a high correlation of the three transferases GOT, GPT and GGT not only with the reported alcohol consumption but also with the plasma insulin. Most of the insulin increase, however, occurred in that range of the three transferases which, so far, has erroneously been considered to be the normal one. The C-peptide showed the same behaviour. Plasma insulin was also raised in relation to overweight, but only in persons with the sum of the three transferases over 30 U/l, not in persons who did not drink alcohol and who had really normal transferases (sum of the three transferases below 30 U/l measured at 25 degrees C). The quotient of plasma insulin divided by the relative body weight (Broca Index) was constantly low in the range of really normal transferases (up to 30 U/l), thereafter rising significantly, but only in the range of the transferases so far erroneously considered to be the normal one (GOT to 17, GPT to 22, GGT to 28 U/l, thus sum up to 67). Serum glucose in the tolerance test also rose with the transferases but much less than the plasma insulin. The correlation between both GGT and the sum of the three transferases with the plasma insulin was significantly positive and independent of the relative body weight. It is concluded that overweight (which is generally believed to be the main risk factor for non-insulin-dependent diabetes), and insulin resistance (which leads to hyperinsulinaemia), are largely caused by the toxic effects of "normal" daily alcohol, more in the human male than in the female. Hyperinsulinaemia (which blocks lipolysis) is caused by a toxic effect of ethanol and its metabolites, independent of caloric input and overweight. Hyperinsulinaemia is at least in the human male at present, probably the most important cause of obesity. In obesity, caused by "normal" alcohol consumption, a vicious circle occurs: the enhancement of the triglycerides and, consequently, the free fatty acids leads to a further decrease of glucose utilization by the muscle. A continuously high glucose level has toxic effects: eventually the beta cells of the pancreas are exhausted.(ABSTRACT TRUNCATED AT 400 WORDS)

Treatment of acute stroke with calcium antagonists.

Medical treatment in acute stroke is probably more successful when started rapidly after the onset of symptoms. Therefore a drug is necessary which can be applied by the first physician prior to the diagnosis ischaemic versus haemorrhagic stroke by means of imaging methods. In animal models of ischaemic cerebral damage, a cerebroprotective effect of some calcium antagonists could be demonstrated, among them flunarizine and nimodipine. Flunarizine is effective also in experimental cerebral haemorrhage. The results of the first clinical trials with calcium antagonists are encouraging but inconclusive up to now. In view of the limited possibilities of treatment after a stroke, prevention is stressed.

[The normal values of gamma-glutamyltransferase are falsely defined up to now: on the diagnosis of hypertension, obesity and diabetes with reference to "normal" consumption of alcohol]. / GGT-Normbereich bisher falsch definiert: zur Diagnostik von Bluthochdruck, Adipositas und Diabetes infolge "normalen" Alkoholkonsums.

In a large sample of 1379 adult patients and, in addition, in a smaller group of 223 other patients in whom a glucose tolerance test with measurement of serum insulin was carried out, an increase of blood pressure, pulse rate, relative body weight and serum insulin was found which correlated significantly with that range of gamma glutamyltransferase (GGT) values which erroneously so far is considered to be normal. The really normal range of the GGT is not up to 28 (measured at 25 degrees C), but only up to 10 U/l. Persons with GGT 9-12 U/l have a significantly higher blood pressure than persons with GGT up to 8 U/l. The relationship between blood pressure and GGT is the same in males and females although the females show a higher GGT for the same amount of alcohol consumed; in both, males and females, the steepest increase is just in the low GGT range between 9 and 25 U/l. The nature of this ethanol-effect is toxic, not caloric. Daily alcohol in "normal" ("social") amounts causes hyperinsulinemia (and thus increased sodium reabsorption in the Kidney) as well as increased catecholamine excretion. "Normal" alcohol consumption leading to hepatic steatosis as the "normal" condition of the population, has more health hazards than so for assumed. A GGT higher than 10 U/l (measured at 25 degrees C), is besides hyperinsulinemia the most sensitive test for pathologic changes of the metabolism and the cardiovascular parameters due to hepatic steatosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol, smoking and body build: obesity as a result of the toxic effect of 'social' alcohol consumption.

Previous work showed that obesity in the average human male is not due to increased caloric intake. To test the hypothesis that 'social' ethanol consumption causes obesity by a hepatotoxic mechanism, the relationships between alcohol intake, cigarette smoking, serum gamma-glutamyl transpeptidase (GGT) and body build were investigated in 816 adult patients, 491 males and 325 females. A large part of the Broca index variance could be explained by hepatic damage as reflected by the GGT level. The higher the GGT, the more overweight were the subjects. Hyperinsulinemia may be the pathogenetic link; insulin is the strongest known blocker of lipolysis. Almost the total variation of obesity with GGT, however, occurred in the range of GGT up to 25 U/l, which is usually, but nevertheless erroneously, considered to be the normal range. This effect was independent of sex and age. Normal GGT is below 10 U/l, which is found on average in females aged less than 20 years. Females tolerate less alcohol than males. Although GGT is as high in females as in males around age 30, males drink about three times as much ethanol. For the same GGT the Broca index is significantly higher in females than in males. GGT generally increases with age; maximum GGT is reached in females in the age group 21-40 years (due to the change in drinking habits around 1968), declining thereafter; in males at age 50. Obesity per se is not correlated with a high GGT. In the females there are hormonal factors influencing obesity. Although in the females GGT decreases on average after age 40, obesity increases (due to the decrease in estrogens). After age 50 ethanol tolerance in males decreases: they reduce their alcohol consumption, and yet the GGT remains high. -Cigarette smoking is a factor which independently influences obesity. Although people who smoke tend also to drink more alcohol, smokers are significantly leaner than nonsmokers. On average males smoke about twice as heavily as females; this contributes to the fact that on average males are leaner than females despite their higher alcohol consumption. Due to lower consumption the influence of ethanol and smoking on body build is smaller in females than in males.

Guillain-Barré syndrome and serum activities of gamma-glutamyltransferase and glutamic-pyruvic transaminase.

Objective laboratory indicators of alcohol consumption (mean corpuscular volume and serum glutamic-pyruvic transaminase (GPT), glutamyltransferase (gamma-GT), and glutamic-oxaloacetic transaminase (GOT] were measured in 18 patients with Guillain-Barré syndrome (GBS) and 710 control patients. All of the indicators examined were more frequently found to be pathological in GBS patients, reaching significance for gamma-GT and GPT. Some explanations for this result are discussed. It is concluded that alcohol consumption may be a risk factor for GBS.

Cortical slow potentials in verbal and spatial tasks--the effect of material, visual hemifield and performing hand.

Fifteen right-handed students voluntarily initiated the tachistoscopic presentation of visual stimuli containing either verbal (abstract words) or spatial (stereogeometric figures) material. Subjects had to reproduce stimulus material which had been presented either in their right or their left hemifield of vision by writing or drawing, either with their right or their left hand. Material-specific effects were found during the reproduction period: amplitudes of the performance-related negative potential shifts were larger in parietal and occipital recordings (P4, O1, and O2) when drawing as compared to writing. The opposite was true in frontal and left central leads (F3, F4, and C3) where writing was associated with larger negative amplitudes than drawing. Although subjects were informed about the nature of the forthcoming stimulus before voluntarily initiating the task, material-specific effects were missing in the preparation period. The performing hand had an influence on potentials in central leads, whereas hemifield of vision had no effect on preparation- and performance-related slow potential shifts.