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Biomedical subjects

Johannes Schröder

Publications and source records attributed to Johannes Schröder.

At least 19 recordsLinked to original sources

Anterior cervical spinal fusion with the Intromed ZWE System: preliminary experience.

The implantation of a spacer is common practice after ventral discectomy in the cervical spine. Besides bone or bone cement (Palacos, Sulfix, and Allofix), the surgeon has the choice of a variety of factory-made implants (cages). We report on our experience with the Intromed ZWE [Zwischenwirbel-Ersatzsystem (Intervertebral Replacement System)] implant. The ZWE implant (Intromed Medizintechnik GmbH, 15754, Senzig, Germany), made from titanium 6AL 4V, consists of a flat quadrangular body with a large supporting surface on the bottom and top and a central hole. We report the first 100 cases treated with their 1- or 2-year follow-up completed (mean follow-up, 1.7 years). The mean age was 47+/-9 years (range: 27-73 years). The implantation was performed without filling the central hole. In addition to the clinical investigation of neurological alterations and the range of movement, X-rays were taken, and the clinical result was determined by an independent investigator according to the Odom Scale. After the minimum follow-up of 1 year, 32 patients scored excellent on the Odom scale, 38 patients good, 25 patients satisfactory, and 5 patients bad. In 74 cases, fusion occurred radiologically as bony bridging around the implant. In 21 cases, the cage showed no change and no radiolucency. In five cases, radiolucency around the implant occurred without instability at flexion-extension X-ray views. In CT scans done in two patients with complaints, we confirmed bony bridging inside the centre hole implanted empty. The Intromed-ZWE-System performs well in routine clinical use. Compared to bone or bone cement, the operating time is reduced. The Intromed System offers an easy fusion method for a competitive price.

Adult↗

International quality control survey of neurochemical dementia diagnostics.

UNLABELLED: Currently, neurochemical dementia diagnostics (NDD) are increasingly entering routine clinical neurochemistry, offering improved early and differential diagnosis of dementias. However, there is an obvious lack of standardization in pre-analytical sample handling and systematic quality surveys. Therefore, in this study, 14 laboratories in Germany, Austria, and Switzerland were given aliquots of a human cerebrospinal fluid (CSF) sample, and were asked to measure Alzheimer's disease (AD) biomarkers (amyloid beta (Abeta) peptides, total Tau protein, and phosphorylated Tau protein (P-tau(181P))) according to their routine protocols. RESULTS: The inter-laboratory coefficients of variation of the results obtained by the laboratories participating in this study were in the range of 20-30%. Although the results of this quality control survey are promising, the quality of measurements has to be further optimized.

Alzheimer Disease↗

The Brief Motor Scale (BMS) for the assessment of motor soft signs in schizophrenic psychoses and other psychiatric disorders.

Subtle motor impairment is an important aspect of neurological soft signs (NSS) which are frequently found in psychiatric patients-particularly schizophrenic patients. On the basis of data collected in previous studies using two different NSS scales, the most reliable and discriminative signs of motor impairment were identified to construct a brief 10-item rating scale. Subsequently, the new scale was applied to a sample of subacute patients with schizophrenic psychoses (N = 82) and healthy controls (N = 33). Factor analysis identified two factors which were labeled "motor coordination" and "motor sequencing". Both the total score and the subscores showed high internal consistency and test-retest reliability. There were highly significant group differences on the total score and the subscores as well as on each individual task. The scale has high sensitivity (84.1%) and specificity (87.9%) indicating that it may provide an effective instrument for the screening of subjects with neurodysfunction as well as for monitoring motor dysfunction in the clinical course of psychiatric disorders.

Adolescent↗

Motoric neurological soft signs and psychopathological symptoms in schizophrenic psychoses.

Motoric neurological soft signs (NSS) were investigated by means of the Brief Motor Scale (BMS) in 82 inpatients with DSM-III-R schizophrenic psychoses. To address potential fluctuations of psychopathological symptoms and extrapyramidal side effects, patients were examined in the subacute state, twice at an interval of 14 days on the average. NSS were significantly correlated with severity of illness, lower social functioning, and negative symptoms. Modest, but significant correlations were found between NSS and extrapyramidal side effects as assessed on the Simpson-Angus Scale. Neither the neuroleptic dose prescribed to the patient, nor scores for tardive dyskinesia and akathisia were significantly correlated with NSS. Moreover, NSS scores did not significantly differ between patients receiving clozapine and conventional neuroleptics. Patients in whom psychopathological symptoms remained stable or improved over the clinical course showed a significant reduction of NSS scores. This finding did not apply to those patients in whom psychopathological symptoms deteriorated. Our findings demonstrate that NSS in schizophrenic psychoses are relatively independent of neuroleptic side effects, but they are associated with the severity and persistence of psychopathological symptoms and with poor social functioning.

Adolescent↗

Perceived criticism in schizophrenia: a comparison of instruments for the assessment of the patient's perspective and its relation to relatives' expressed emotion.

The expression and perception of expressed emotion (EE) in schizophrenic patients and their relatives are likely to differ. The presented exploratory study compares the two views. EE in relatives of 25 chronic schizophrenic patients was assessed using an extended version of the Five-Minute Speech Sample (FMSS). Patients rated their relatives with the Perceived Criticism Scale (PCS), the Family Emotional Involvement and Criticism Scale (FEICS), and a German questionnaire on family atmosphere (FEF). Forty-eight percent of relatives were rated high in EE, due to criticism in all cases but one. Patients' assessments of the whole family on the FEICS and FEF criticism subscales were related to their relatives' EE status. Correlations between the self-rating instruments were moderate to good. As the patients' and the relatives' views corresponded with regard to the criticism domain, the application of a self-rating instrument may be a simple and useful tool for clinical and research purposes.

Adult↗

Arthrodesis of small joints, illustrated by the carpometacarpal joint of the thumb.

OBJECTIVE: Elimination of pain, impairment of function, and loss of power due to basal joint osteoarthritis of the thumb. INDICATIONS: Idiopathic or posttraumatic osteoarthritis of the basal joint of the thumb. The technique is equally suitable for arthrodesis of the first tarsometatarsal joint or the first metatarsophalangeal joint following a failed Keller-Brandes operation or failed prosthesis. CONTRAINDICATIONS: Total or subtotal resection of the trapezium. Osteoarthritis of the distal scaphoid joint (triscaphoid joint). SURGICAL TECHNIQUE: Technique for a stable fixation of small joints, illustrated by arthrodesis of the carpometacarpal joint of the thumb. A plate is bent distally and used as a washer for a small-fragment compression screw, crossing the former joint space and the inserted bone graft. Additional compression is achieved by asymmetric drilling of the proximal screw (asymmetric insertion principle). POSTOPERATIVE MANAGEMENT: Plaster splint for 5 days, then early functional treatment. RESULTS: In a clinical trial, 16 patients with idiopathic basal joint osteoarthritis of the thumb (18 joints) were followed up for an average of 6 years postoperatively. The main objective of the operation, namely, pain relief, was achieved in all cases. Only one case required revision due to nonunion.

Aged↗

Dissociation between CSF total tau and tau protein phosphorylated at threonine 231 in Creutzfeldt-Jakob disease.

To study the potential diagnostic value of abnormally phosphorylated tau protein in Creutzfeldt-Jakob disease (CJD) compared to Alzheimer's disease (AD), we determined levels of tau phosphorylated at threonine 231 (p-tau231) and of total tau (t-tau) in cerebrospinal fluid (CSF) of CJD patients, AD patients, and healthy controls (HC). CJD patients showed excessively high t-tau levels but relatively low p-tau(231) concentrations compared to the AD group. t-tau alone yielded the best diagnostic accuracy to differentiate between CJD and AD patients, when compared to p-tau231 and the p-tau231/t-tau ratio (97, 78, and 95% correctly allocated cases, respectively). Our findings indicate a dissociation in the direction of change in CSF levels of t-tau and p-tau231 in CJD when compared to AD.

Age Distribution↗

Antibodies against Gag are diagnostic markers for feline foamy virus infections while Env and Bet reactivity is undetectable in a substantial fraction of infected cats.

Spumaretroviruses or foamy viruses constitute a distinct subfamily of retroviruses. The biology of foamy viruses within the authentic host, their mode of transmission, and disease potential in the authentic host or after zoonotic transmission into human or other species are almost unknown. Using feline foamy virus (FFV) as model system, we established modular enzyme-linked immunosorbent assays (ELISA) suited to determine feline IgG and IgM antibody responses against structural and non-structural FFV proteins. We validated the ELISAs with standard reference sera. In 99 cats admitted to a Swiss veterinary hospital, overall FFV Gag antibody prevalence was 36%, reactivity against Env and the non-structural protein Bet each was about 25%, and 19% of the sera were directed against all three FFV antigens. With one exception, all Bet- and/or Env-positive sera were also positive for Gag. In this small epidemiological pilot study, FFV antibodies were not significantly associated with clinical disease.

Animals↗

Reduced cerebellar volume and neurological soft signs in first-episode schizophrenia.

Recent studies indicate that morphological and functional abnormalities of the cerebellum are associated with schizophrenia. Since the cerebellum is crucial for motor coordination, one may ask whether the respective changes are associated with motor dysfunction in the disease. To test these hypotheses in a clinical study, we investigated cerebellar volumes derived from volumetric magnetic resonance imaging of 37 first-episode patients with schizophrenia, schizophreniform or schizoaffective disorder and 18 healthy controls matched for age, gender and handedness. To control for potential interindividual differences in head size, intracranial volume was entered as a covariate. Neurological soft signs (NSS) were examined after remission of acute symptoms. Compared with the controls, patients had significantly smaller cerebellar volumes for both hemispheres. Furthermore, NSS in patients were inversely correlated with tissue volume of the right cerebellar hemisphere partialling for intracranial volume. No associations were detected between cerebellar volumes and psychopathological measures obtained at hospital admission when patients were in the acute psychotic state or after remission, treatment duration until remission, treatment response or prognostic factors, respectively. These findings support the hypothesis of cerebellar involvement in schizophrenia and indicate that the respective changes are associated with NSS.

Adult↗

Mean age of onset in familial Alzheimer's disease is determined by amyloid beta 42.

More than 130 known mutations in the presenilin-1 (PS1) gene result in familial Alzheimer's disease (FAD) with a mutation specific age of disease onset. These mutations increase amyloid beta 42 (A beta42) levels, and this increase has been validated in recent years as one pathogenic factor in FAD. However, further malfunctions of mutant presenilin-1 are discussed as well. In order to assess the weight of A beta42 regarding the pathogenesis of FAD, we expressed mutant forms of PS1 (30-65 years onset age) in COS-7 cells and analyzed amyloid beta levels by a novel ELISA. We found a strong correlation (r = 0.98; p<0.001) between the A beta40/42-ratio and mean age of disease onset indicating a substantial extent of A beta42 contribution to FAD pathology. Our data strongly suggest that A beta42 is the decisive factor for age of onset in FAD.

Adult↗

Prevalence and natural course of aging-associated cognitive decline in a population-based sample of young-old subjects.

OBJECTIVE: "Mild cognitive impairment" refers to cognitive deficits in older age that exceed age-related cognitive decline but do not fulfill criteria for dementia. Affected subjects are assumed to be at higher risk for the development of dementia, such as Alzheimer's disease. However, little is known about the group of young-old subjects with respect to the prevalence and natural course of cognitive decline. METHOD: Within the population-based Interdisciplinary Longitudinal Study on Adult Development and Aging, neuropsychological functioning was assessed in 500 community-dwelling young-old subjects of two German urban regions who were born during 1930-1932. The participants were carefully screened for physical and mental health and reexamined 4 years later. The concept of "aging-associated cognitive decline" was applied. RESULTS: At baseline, 13.4% of the subjects fulfilled criteria for aging-associated cognitive decline. Four years later, the prevalence rates for rose to 23.6%; 52.3% of the subjects initially classified as having aging-associated cognitive decline retained the diagnosis at follow-up. Although subjects with aging-associated cognitive decline showed a reduced performance in all neuropsychological domains addressed, a significant decline was confined to delayed verbal memory test performance during the 4-year follow-up period in relation to comparison subjects. Aging-associated cognitive decline did not predict conversion to dementia during the follow-up interval. CONCLUSIONS: In young-old community-dwelling individuals, aging-associated cognitive decline is a frequent condition with a high temporal stability. During a 4-year follow-up, subjects with aging-associated cognitive decline deteriorated specifically in measures of episodic memory, underscoring the value of the respective deficits in characterizing "mild cognitive impairment."

Adult↗

Neurological soft signs in first-episode schizophrenia: a follow-up study.

OBJECTIVE: Neurological soft signs are frequently found in schizophrenia. They are indicators of both genetic liability and psychopathological symptoms. To further differentiate "trait" and "state" relations the authors compared the 1-year course of neurological soft signs in schizophrenia patients and comparison subjects. METHOD: Thirty-nine patients with first-episode schizophrenia spectrum disorders were examined after remission of acute symptoms and 14 months later. Established instruments assessed diagnoses, psychopathological symptoms, predictors of outcome, handedness, and neurological soft signs. Twenty-two age- and gender-matched comparison subjects were also examined twice. RESULTS: Neurological soft sign scores in patients were significantly elevated relative to comparison subjects at both measurement points. Whereas neurological soft signs remained stable in comparison subjects (time 1: mean=4.8, SD=3.3; time 2: mean=4.6, SD=3.9), they significantly decreased in patients (time 1: mean=15.7, SD=7.1; time 2: mean=10.1, SD=7.9). This effect was more pronounced in patients with a favorable versus a chronic course and was mainly accounted for by motor signs. Predictors of follow-up neurological soft sign scores were neurological soft sign levels at remission and compliance with treatment. CONCLUSIONS: Although neurological soft signs are intrinsic to schizophrenia, their level varies with the clinical course. Thus, neurological soft signs may correspond to both genetic liability and the activity of the disease process and may be considered as potential predictors of outcome.

Adult↗

Distribution of cerebral atrophy assessed by magnetic resonance imaging reflects patterns of neuropsychological deficits in Alzheimer's dementia.

Neuropsychological deficits were investigated with respect to regional distribution of cerebral atrophy as assessed by volumetric magnetic resonance imaging (MRI) in 50 patients with Alzheimer's dementia (AD; NINCDS-ADRDA criteria) and 20 healthy volunteers. When compared between groups, test performance of all investigated neuropsychological domains including declarative memory, language, praxia, psychomotor speed, as well as attention and concentration was significantly impaired. These deficits were differentially correlated with regional atrophic changes. In particular, volumes of the right amygdala-hippocampus complex correlated with declarative memory performance, whereas volumes of the left temporo-parietal regions correlated with performance in naming and praxia. Furthermore, left frontal lobe atrophy was associated with verbal fluency. Our data confirm the central role that medial temporal atrophy plays for declarative memory deficits in AD and indicate that additional changes in the parietal, temporal and frontal lobes are responsible for further neuropsychological deficits characteristic of this disorder.

Aged↗

Plasticity of cortical activation related to working memory during training.

OBJECTIVE: Although it is well established that cerebral activation increases with higher task load, the potential effects of training have been investigated over brief periods only. Training is of potential clinical relevance since training programs are an essential part of psychiatric therapy. METHOD: Cerebral activation during a visual spatial working memory task was examined before, during, and after 4 weeks of daily training in nine healthy subjects using functional magnetic resonance imaging. RESULTS: All subjects showed a pronounced activation mainly involving the right inferior frontal gyrus and the right intraparietal sulcus. While the respective regions showed activation increases with improved performance after 2 weeks of training, the activation values decreased at the time of consolidation of performance gains after 4 weeks. CONCLUSIONS: Our results suggest that training-related cerebral activation changes follow an inverse U-shaped quadratic function and raise the prospect of investigating cerebral mechanisms underlying training effects.

Adult↗

Hippocampal glucose metabolism is associated with cerebrospinal fluid estrogen levels in postmenopausal women with Alzheimer's disease.

Animal studies indicate that estrogens, such as 17beta-estradiol (E(2)), may enhance hippocampal metabolism and function. In postmenopausal Alzheimer's disease (AD) patients, cerebrospinal fluid (CSF) E(2) levels were significantly lower than in non-demented controls. This finding was inversely correlated with CSF beta-amyloid levels. To address the potential impact of this finding, E(2) levels in CSF were correlated with regional cerebral [18F]2-fluoro-2-deoxy-D-glucose (FDG) uptake as measured using positron emission tomography (PET) in six postmenopausal AD patients. CSF E(2) levels were determined using an electro-chemiluminescence-immunoassay on the Roche Elecsys 2010 immunoassay analyzer. Basic image processing was done by MEDx, using SPM routines for spatial normalization and statistics. CSF E(2) levels were significantly correlated with cerebral glucose metabolism in the left hippocampus. This is the first clinical study indicating an association between CSF E(2) concentration and hippocampal glucose metabolism in postmenopausal women with AD.

Aged↗

Cerebrospinal fluid tau levels in Alzheimer's disease are elevated when compared with vascular dementia but do not correlate with measures of cerebral atrophy.

Increased tau levels are a well-established finding in Alzheimer's disease (AD). In contrast, the potential value of tau levels in the differential diagnosis of AD, vascular dementia (VD) and major depression warrants further investigation. The potential impact of psychotropic medication also needs to be established. We investigated cerebrospinal fluid (CSF) tau protein concentrations in 88 patients with AD, 23 patients with VD, 25 patients with major depression and 17 age-paralleled controls without cognitive impairment with respect to important clinical variables, type and dosage of psychotropic medication and cerebral changes as assessed by magnetic resonance imaging (MRI). The AD patients showed significantly elevated tau levels compared with patients with VD or major depression and controls. Tau levels obtained in the VD group were intermediate, with significant differences from both AD patients and patients with major depression and controls. Within the AD group, no significant correlation between tau levels, severity of dementia, age, duration of disease, type and dosage of psychotropic medication or MRI volumetric changes arose. A subgroup of AD patients without increased tau levels was characterized by a significantly larger percentage of patients with presenile onset.

Aged↗