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Biomedical subjects

K Weissenborn

Publications and source records attributed to K Weissenborn.

At least 19 recordsLinked to original sources
PubMed2006

Monoaminergic neurotransmission is altered in hepatitis C virus infected patients with chronic fatigue and cognitive impairment.

BACKGROUND: The majority of patients with hepatitis C virus (HCV) infection suffer from disabling fatigue, cognitive dysfunction, and quality of life reduction. Meanwhile, there is increasing evidence that HCV infection can affect brain function. Recent studies have shown that fatigue and psychomotor slowing may resolve in patients with hepatitis C after treatment with ondansetron. This observation indicates alteration of serotonergic neurotransmission in HCV infected patients with chronic fatigue. METHODS: Data from 20 HCV infected patients who were referred to our clinic because of disabling fatigue and cognitive decline of unknown cause were analysed retrospectively. Patients had undergone a diagnostic programme, including clinical and psychometric examination, electroencephalogram (EEG), magnetic resonance imaging of the brain, cerebrospinal fluid analysis, and I-123-beta-CIT (2beta-carbomethoxy-3-beta-(4-[(123)I]iodophenyl)tropane) single photon emission computerised tomography (SPECT) studies of serotonin and dopamine transporter binding capacity. RESULTS: All patients had pathological results on the fatigue impact scale. Two thirds of patients showed pathological attention test results. EEG, magnetic resonance imaging, and cerebrospinal fluid analysis were normal. Pathological dopamine transporter binding was present in 12/20 (60%) patients and pathological serotonin transporter binding in 8/19 (50%) patients. Patients with normal SPECT results did not significantly differ from controls with regard to psychometric test results. Interestingly, patients with both decreased serotonin and dopamine transporter binding showed significantly impaired performance in most of the tests applied. Comorbidity that could have impaired cerebral function was excluded in all patients. CONCLUSION: Our findings indicate alteration of serotonergic and dopaminergic neurotransmission in HCV infected patients with chronic fatigue and cognitive impairment.

Adult↗
PubMed2006

EFNS guidelines on management of neurological problems in liver transplantation.

Neurological impairment after orthotopic liver transplantation (OLT) is common and represents a major source of morbidity and mortality. The diagnosis and management of neurological problems occurring after OLT are difficult and evidence-based guidelines for this task are currently lacking. A Task Force was set up under the auspices of the European Federation of Neurological Societies to devise guidelines to prevent and manage neurological problems in OLT. We selected six major neurological problems and approached them combining an evidence-based scientific literature analysis with a search of consensus by means of a Delphi process. Search results were translated into a series of recommendations constituting a basis for better care of patients with neurological complications after OLT.

Advisory Committees↗
PubMed2004

Dissection of the brain supplying arteries over the life span.

Cervical artery dissection (CAD) is being increasingly diagnosed due to improved neuroimaging methods. The mean age of patients with CAD is about 40 years, with a peak between 40 and 45 years of age. Proven data on the incidence of CAD in older patients are missing. Therefore, whether CAD should also be considered as a probable cause of cerebral ischemic events in the elderly was investigated. All consecutive patients referred to our clinic with a diagnosis of cerebral ischemia from January 1999 until June 2000 were thoroughly assessed for the presence of CAD. In addition, the records of all stroke patients treated in our department from January 1995 to December 1998 were analysed retrospectively for a diagnosis of CAD. A total of 34 patients (11 women) had suffered from internal carotid (n = 29) or vertebral artery (n = 5) dissection. Their mean (SD) age was 50.3 (14.6) years, with 32.4% being older than 60 years. Clinical presentation of CAD did not differ depending on the patients' age. The results show that CAD is a possible cause of cerebral ischemia in the elderly and thus has also to be considered in the diagnostic investigation in this patient group.

Adult↗
PubMed2002

[Lipomatosis dolorosa--a frequently overlooked disease picture].

Dercum's disease (lipomatosis dolorosa) is a relatively unknown illness. The disorder usually affects middle-aged females. Subcutaneous fatty tissue deposits may occur in many parts of the body. The upper arms, elbows, stomach wall, buttocks, thighs, or knees are most commonly affected. Severe hyperalgesia is found on light pressure and touch. Analgesics or pain-modulating drugs usually have little or no effect. The following case report demonstrates successful symptomatic treatment of the otherwise nearly unbearable complaints: intravenous infusions of 5 mg/kg body weight of lidocaine over 30-90 min may give pain relief lasting several weeks or even months. Alternatively, patients are treated with 150-750 mg orally administered mexiletine daily. Surgical excision or liposuction of these fatty tissue deposits have shown significant reduction of pain. However, this effect reduces over time and recurrences often develop.

Adiposis Dolorosa↗
PubMed2001

Attention deficits in minimal hepatic encephalopathy.

Minimal hepatic encephalopathy (HE) is characterized by a decrease of psychomotor speed, and deficits in visual perception, visuo-spatial orientation, and visuo-constructive abilities. Attention deficits have also been proposed to be part of the syndrome. Several attempts were made in the past to elaborate suitable psychometric means for the assessment of minimal HE. However, there is still no "gold standard" for the diagnosis of minimal HE. We recently evaluated the so called "PSE-Test" for the assessment of minimal HE, a test battery which does not include a test predominantly aimed at the assessment of attention. We therefore presented a battery of attention tests in addition to the PSE-Test to a group of cirrhotics without clinical signs of HE compared to a healthy control group matched for age and education to determine whether the addition of special attention tests would increase the diagnostic sensitivity of the PSE-Test. It was shown that the patients with a pathological PSE-Test result differed significantly from controls in all attention tests applied, while the patients with normal PSE-Test results achieved attention test results similar to that of the controls. Thus, the PSE-Test results represent attention deficits as well as deficits in motor skills, visuo-spatial orientation, and visual construction.

Adult↗
PubMed2000

Altered striatal dopamine D2 receptor density and dopamine transport in a patient with hepatic encephalopathy.

A patient suffering from liver cirrhosis presented with a bradykinetic-rigid syndrome suspected as Parkinson's disease. A detailed work-up of the case revealed hepatic encephalopathy as the cause of the neurological symptomatology. An alteration of striatal dopamine D2 receptor binding and dopamine re-uptake sites was demonstrated by 123I-iodobenzamide (IBZM) and 123I-beta-CIT single photon emission computed tomography (SPECT), respectively. It is suggested that the alteration of the dopamine re-uptake in cirrhotics may be the cause of an increased catabolism of dopamine in HE.

Aged↗
PubMed1999

[Concepts for stroke therapy].

Thrombolytic therapy and "stroke units" are the main new concepts of stroke therapy that have been recently introduced into clinical practice. Although thrombolysis decreases the likelihood of disability by about 12% with regard to increased mortality and a tenfold increase of bleeding complications, debate over the value of thrombolytic therapy in acute ischaemic stroke continues. Local intra-arterial application of thrombolytic substances, however, is recommended for embolic occlusion of the basilar artery, since thrombolytic therapy reduces mortality in these patients from about 90% to less than 50%. "Stroke units" have been developed to enable rapid evaluation of stroke patients and to improve medical care of the patients. Several studies have shown that stroke unit care of the patients indeed improves outcome with decreased mortality, a better chance of the patient being discharged to home after hospital stay, shorter length of hospital stay, as well as fewer medical complications.

Cerebrovascular Disorders↗
PubMed1998

The number connection tests A and B: interindividual variability and use for the assessment of early hepatic encephalopathy.

BACKGROUND/AIMS: The number connection tests A and B are regarded as sensitive psychometric measures for the assessment of early hepatic encephalopathy. Review of the studies dealing with the diagnostic sensitivity of the number connection tests, however, shows that the scoring of the number connection tests results differs between studies. Most groups define the limits of the normal range by studying small control groups. Others use scores given in the literature without ensuring the comparability of the test versions used. Thus, there is a need for normative data for the number connection test results and for re-evaluation of the sensitivity of the tests using valid scores. METHODS: In this study the number connection tests A and B were administered to 249 healthy volunteers (age: 18 to 76 years) to analyze the influence of age, education and occupation on their results. In addition, the age-corrected normative data were applied to 169 patients with grade 0-I hepatic encephalopathy. The specificity and sensitivity of age-corrected and age-independent normative data of the number connection tests were compared. RESULTS: There was a significant influence of age and education on the number connection test results, but only a negligible effect of occupation. Application of the age-corrected normative data to the test results of the patients with grade I hepatic encephalopathy significantly decreased the sensitivity of the number connection tests for hepatic encephalopathy compared to widely used age-independent normal ranges, but also increased the specificity. CONCLUSION: The use of standardized versions of the number connection tests and age-related normative data is recommended.

Acute Disease↗
PubMed1998

The basal ganglia and portal-systemic encephalopathy.

Despite decades of research, the pathogenesis of portal-systemic encephalopathy (PSE) remains puzzling. Current hypotheses on the pathophysiology of PSE usually deal with metabolic toxins like ammonia or disturbances in neurotransmitter systems, especially glutamatergic or GABA-ergic neurotransmission. With respect to clinical, neuropathological, MRI and PET findings this review advances the hypothesis that the known alterations of neurotransmission and astrocytic function in PSE might impair basal ganglia function in cirrhotics. The symptoms of PSE - whether cognitive, emotional or motor - are proposed to be a consequence of basal ganglia dysfunction.

Basal Ganglia↗
PubMed1998

Psychiatric aspects of portal-systemic encephalopathy.

This paper focuses on psychiatric aspects of portal-systemic encephalopathy (PSE) due to chronic liver disease and/or portal-systemic shunting. Clinical syndromes of PSE are discussed from the point of view of biological psychiatry, but, psychological consequences of concomitant cognitive disorders are also addressed. Psychiatric symptoms of early PSE and sleep disorders in patients with chronic liver disease are of specific interest.

Affect↗
PubMed1998

P300 after minor head injury (a follow-up examination).

BACKGROUND AND METHODS: The aim of the study was to examine whether--like in severe head injuries--the endogenous evoked potential P300 is influenced by minor head injury (MHI) and how the eventual abnormalities develop within a follow-up period of 8 weeks after trauma. Therefore we examined the cognitive auditory evoked potential P300 (latency, amplitude), the neurologic state and the performance in psychometric testing (Mini-Mental-State, Number Connection test part A and B) in 15 patients within the first 24 hours as well as 1, 3 and 8 weeks after MHI. The P300 results were compared to the age-related normal ranges under consideration of the intra-individual variability. For both parameters normative values were established before in our own laboratory. RESULTS: For the patient group as a whole the mean values for P300 latency and amplitude were always within the age-related normal range and normal intra-individual long-term variability of healthy controls, respectively. Significant posttraumatic prolongations of P300 latency were exclusively observed in the only 20% of our patients with clinically suspected posttraumatic organic brain syndrome. These prolongations of latency decreased during follow-up and on the last examination the latencies were normalised. Compared to psychometric tests, P300 latency seems to be more sensitive in early detection of cerebral dysfunction. CONCLUSIONS: We conclude that, in contrast to severe head injury, in general the P300 is not affected by minor head injury. If there are clinical signs of organic brain syndrome following MHI posttraumatic prolongation of P300 latency is a marker of cerebral dysfunction and may serve as a valuable parameter for follow-up examination and documentation.

Adolescent↗
PubMed1997

An image of the brain in patients with liver disease.

As imaging techniques have advanced from those that are based on tissue density and hence are strictly anatomical in nature, to include those based on physiologic and biochemical factors, the expectation has grown that imaging will be used to evaluate patients with diseases that are caused by disordered metabolism. In this review, recent advances in neuroimaging are discussed that have led to new insights into the pathophysiology of hepatic encephalopathy, a common condition that is caused by the failure of the liver to remove metabolic wastes from the blood.

Animals↗
PubMed1997

Classification of Sneddon's syndrome.

BACKGROUND: The combination of generalized broken ("racemose") livedo and cerebrovascular accidents is referred to as "Sneddon's syndrome". Although several pathogenetic factors have been suggested the aetiology of Sneddon's syndrome is unknown. Furthermore, considerable variability of patient characteristics gives rise to the question whether "Sneddon's syndrome" denotes a homogeneous disease entity at all. We hypothesized that the diagnosis "Sneddon's syndrome" can be broken down into different subgroups according to possible aetiologic factors. PATIENTS AND METHODS: Thirty-two patients with the combination of generalized broken livedo and cerebrovascular accidents were evaluated by clinical examination, routine diagnostic procedures, MRI of the brain, echocardiography, vascular ultrasound, immunologic and haemostaseologic testing. Patient groups were formed, depending on (1) whether or not an additional feature with a possibly aetiologic role for Sneddon's syndrome was present, and (2) which kind of feature it was. RESULTS: In 16 out of 32 patients, diagnostic features with an implication for the pathogenesis of Sneddon's syndrome could be identified. An autoimmune disorder was diagnosed in six patients. A thrombophilic state was detected in six patients. Three patients had preexisting atherosclerosis. One patient suffered from an embolizing atrial myxoma. Extent and kind of cerebral pathology differed between patient groups as did the kind of cardiac involvement. CONCLUSION: Sneddon's syndrome is not a homogeneous disease entity. Patients should be classified as "primary Sneddon's syndrome" if no aetiologic factor can be detected. On clinical grounds, this from differs from several varieties of "secondary Sneddon's syndrome" which occurs mainly as part of an autoimmune disorder or in a thrombophilic state.

Adult↗
PubMed1996

Superselective intra-arterial amytal (Wada test) in temporal lobe epilepsy: basics for neuroradiological investigations.

We describe the angioarchitecture of the medial temporal region as a basis for modified superselective Wada tests in patients with temporal lobe epilepsy. Possible functional deficits following the injection of amytal, depending on the superselective placement of the microcatheter in the medial temporal arteries, are discussed. The individual blood supply in each patient determines the ideal super-selective positioning of the micro-catheter.

Amobarbital↗