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Biomedical subjects

E Körner

Publications and source records attributed to E Körner.

At least 19 recordsLinked to original sources
PubMed2005

Ictal dystonic posturing in mesial versus neocortical temporal lobe seizures.

PURPOSE: Ictal contralateral dystonic posturing is a frequently observed clinical feature in temporal lobe seizures. It is generally interpreted as the result of spread of the ictal discharge into basal ganglia structure. In previous reports, analysing ictal behavior, a precise definition and description of the upper limb ictal dystonia is often lacking or contradictory. In our study we aimed to determine whether different subtypes of dystonia and their latency from the clinical onset of seizure might be of value for the differentiation between mesial temporal lobe epilepsy (MTLE) and neocortical temporal lobe epilepsy (NTLE). METHODS: Eighty seizures (51 MTLE and 29 NTLE) and 30 patients (20 MTLE and 10 NTLE) were analyzed with regard to dystonic posturing of the upper limb. Ictal dystonia was subdivided into different subtypes according to distinct clinical features. Their frequency and latency from the clinical onset of seizure were assessed. RESULTS: Frequencies of all subtypes were similar in MTLE and NTLE. Concerning the latencies contralateral dystonic posturing characterized by sustained muscle contractions with flexion of the wrist and fist closure, a frequently appearing feature, occurred significantly earlier in NTLE than in MTLE seizures. CONCLUSIONS: This difference between the two groups may provide a differentiation between an epileptic focus of mesial from neocortical temporal lobe origin.

Adult↗
PubMed2002

Future aspects of the presurgical evaluation in epilepsy.

Epilepsy surgery is a successful therapeutic approach in patients with medically intractable epilepsy. The presurgical evaluation aims to detect the epileptogenic brain area by use of different diagnostic techniques. In this review article the current diagnostic procedures applied for this purpose are described. The diagnostic armamentarium can be divided conceptually into three different groups: assessment of function/dysfunction, structural/morphologic imaging methods and functional neuroimaging techniques. Properties, diagnostic power and limits of all diagnostic tools used in the diagnostic evaluation are discussed. In addition, future perspectives and the diagnostic value of new technologies are mentioned. Some are increasingly gaining acceptance in the routine preoperative diagnostic procedure like MR volumetry or MR spectroscopy of the hippocampus in patients with temporal lobe epilepsy. Some, on the other hand, like MEG and 11C-flumazenil PET, still remain experimental diagnostic tools as they are technically demanding and cost intensive. Besides the refinement of established techniques, co-registration of different modalities like spike-triggered functional MRI will play an important role in the non-invasive detection of the epileptic seizure focus and may change the regimen of the preoperative diagnostic work up of epilepsy patients in the future.

Brain Diseases↗
PubMed2000

Phenotypic and genotypic heterogeneity in hereditary motor neuronopathy type V: a clinical, electrophysiological and genetic study.

We report on a large four-generation Austrian family with autosomal dominant distal hereditary motor neuronopathy type V (distal HMN V). Forty-seven at-risk family members, of whom 21 were definitely affected, underwent detailed clinical, electrophysiological and genetic studies. The age at onset was in the second decade of life in most affected individuals, but clinical presentation was rather variable. While the majority of patients were primarily disabled by progressive asymmetrical wasting of the thenar and the first dorsal interosseus muscles, others had marked foot deformity and gait disturbance with the occasional absence of hand involvement. Sensation sense was normal except for the reduced response to vibration. Many individuals showed brisk tendon reflexes and some elevated muscle tone in the lower limbs, but extensor plantar responses were rarely observed. Electrophysiological evaluation revealed normal or reduced motor nerve conduction velocities, normal or prolonged distal motor latencies, and low compound motor action potentials, depending on the degree of muscle wasting. Sensory nerve studies were usually within the normal range or slightly to moderately abnormal in older or severely affected persons. Electromyography showed high-amplitude motor unit potentials and reduced recruitment compatible with anterior horn cell degeneration. Central motor conduction times were prolonged in two-thirds of the patients. Molecular genetic studies excluded Charcot-Marie-Tooth 1A syndrome and proximal spinal muscular atrophy linked to chromosome 5q as well as the known gene loci for distal HMN II on chromosome 12q, HMN V on chromosome 7p and juvenile amyotrophic lateral sclerosis on chromosome 9q. The findings in this family thus provide detailed clinical and electrophysiological information on HMN V and demonstrate broad phenotypic variability in this disorder. Hallmark features are discussed that appear to be most reliable to differentiate this type of HMN V from other variants of hereditary neuropathies, and a set of diagnostic criteria is proposed. Furthermore, this is the first report of prolonged central motor conduction times in HMN V, which indicates additional involvement of the central motor pathways in this disease. Finally, molecular genetic studies demonstrate genetic heterogeneity, suggesting the existence of at least a second genetic subtype in HMN V.

Adolescent↗
PubMed2000

Gamma knife radiosurgery for hypothalamic hamartomas in patients with medically intractable epilepsy and precocious puberty. Report of two cases.

Hamartoma of the hypothalamus represents a well-known but rare cause of central precocious puberty and gelastic epilepsy. Due to the delicate site in which the tumor is located, surgery is often unsuccessful and associated with considerable risks. In the two cases presented, gamma knife radiosurgery was applied as a safe and noninvasive alternative to obtain seizure control. Two patients, a 13-year-old boy and a 6-year-old girl, presented with medically intractable gelastic epilepsy and increasing episodes of secondary generalized seizures. Abnormal behavior and precocious puberty were also evident. Magnetic resonance (MR) imaging revealed hypothalamic hamartomas measuring 13 and 11 mm, respectively. After general anesthesia had been induced in the patients, radiosurgical treatment was performed with margin doses of 12 Gy to 90% and 60% of isodose areas, covering volumes of 700 and 500 mm3, respectively. After follow-up periods of 54 months in the boy and 36 months in the girl, progressive decrease in both seizure frequency and intensity was noted (Engel outcome scores IIa and IIIa, respectively). Both patients are currently able to attend public school. Follow-up MR imaging has not revealed significant changes in the sizes of the lesions. Gamma knife radiosurgery can be an effective and safe treatment modality for achieving good seizure control in patients with hypothalamic hamartomas.

Adolescent↗
PubMed1999

A model of computation in neocortical architecture.

We propose that the specific architecture of the neocortex reflects the organization principles of neocortical computation. In this paper, we place the anatomically defined concept of columns into a functional context. It is provided by a large-scale computational hypothesis on visual recognition, which includes both, rapid parallel forward recognition, independent of any feedback prediction, and a feedback controlled refinement system. Short epochs of periodic clocking define a global reference time and introduce a discrete time for cortical processing which enables the combination of parallel categorization and sequential refinement. The presented model differs significantly from conventional neural network architectures and suggests a novel interpretation of the role of gamma oscillations and cognitive binding.

Journal Article↗
PubMed1998

Roussy-Lévy syndrome is a phenotypic variant of Charcot-Marie-Tooth syndrome IA associated with a duplication on chromosome 17p11.2.

The Roussy-Lévy syndrome (MIM #180800) was described in 1926 as a disorder presenting with pes cavus and tendon areflexia, distal limb weakness, tremor in the upper limbs, gait ataxia and distal sensory loss. We report a family with affected members in four generations, showing these clinical signs of Roussy-Lévy syndrome and a partial duplication at chromosome 17p11.2. This genetic defect is commonly found in patients with the hypertrophic form of the Charcot-Marie-Tooth syndrome. Our finding provides evidence against the Roussy-Lévy syndrome as a distinct entity but suggests a close relation with the Charcot-Marie-Tooth syndrome. What causes the additional features of gait ataxia and essential tremor needs further clarification.

Action Potentials↗
PubMed1998

[Practice-oriented control of BVD virus infection in cattle herds].

The BVD-virus-infection is at present the economically most important disease of bovine animals. A control program requires to take into consideration the given epidemiological facts. Sufficient diagnostic examination procedures are available for estimation of the infection taking place in a herd. An effective preventive measure prior to the infection as well as the quick limitation of an already existing infection taking place consists in a consequent vaccination program. Pre-condition for the vaccination program is the attention to a strict indication of vaccines available, the detailed information of the animal owner as well as taking into consideration the cost-profit-proportion of the envisaged control measurements.

Animals↗
PubMed1993

Multiple sclerosis-like syndrome in a woman heterozygous for adrenoleukodystrophy.

A 28-year-old asymptomatic woman was diagnosed to be heterozygous for adrenoleukodystrophy (ALD) by elevated very long-chain fatty acids in serum and fibroblasts after ADL had been diagnosed in her son. A year later she had transient unilateral blurred vision. Evoked potentials and brain magnetic resonance imaging showed further separate cerebral white matter lesions suggesting multiple sclerosis (MS). MS-like syndromes in women heterozygous for ALD may be more frequent than previously recognized.

Adrenoleukodystrophy↗
PubMed1991

[EEG mapping in schizophrenia and depression--a multivariate approach].

EEG Brain Mapping offers a promising approach to study complex pattern of brain function. However, traditional usage of this method was focussed mainly on isolated details of the whole specter. The present study was, therefore, aimed at the simultaneous observation of all available parameters. Discriminant analysis was used to distinguish between 4 groups of patients suffering from either schizophrenia (acute/off drugs; improved/on drugs) or depression (acute/off drugs; improved/on drugs) and healthy volunteers, each group with n = 10. The multivariate pattern of 50 topographical spectral variables brought about correct group classification of 49 out of 50 probands. Results suggest that more complex statistical paradigms that take advantage of all available parameters add to an integrative explanation of psychophysiological mechanisms in mental illness.

Acute Disease↗
PubMed1989

Endoscopic surgery versus medical treatment for spontaneous intracerebral hematoma: a randomized study.

A controlled randomized study of endoscopic evacuation versus medical treatment was performed in 100 patients with spontaneous supratentorial intracerebral (subcortical, putaminal, and thalamic) hematomas. Patients with aneurysms, arteriovenous malformations, brain tumors, or head injuries were excluded. Criteria for inclusion were as follows: patients' age between 30 and 80 years; a hematoma volume of more than 10 cu cm; the presence of neurological or consciousness impairment; the appropriateness of surgery from a medical and anesthesiological point of view; and the initiation of treatment within 48 hours after hemorrhage. The criteria of randomization were the location, size, and side of the hematoma as well as the patient's age, state of consciousness, and history of hypertension. Evaluation of outcome was performed 6 months after hemorrhage. Surgical patients with subcortical hematomas showed a significantly lower mortality rate (30%) than their medically treated counterparts (70%, p less than 0.05). Moreover, 40% of these patients had a good outcome with no or only a minimal deficit versus 25% in the medically treated group; the difference was statistically significant for operated patients with no postoperative deficit (p less than 0.01). Surgical patients with hematomas smaller than 50 cu cm made a significantly better functional recovery than did patients of the medically treated group, but had a comparable mortality rate. By contrast, patients with larger hematomas showed significantly lower mortality rates after operation but had no better functional recovery than the medically treated group. This effect from surgery was limited to patients in a preoperatively alert or somnolent state; stuporous or comatose patients had no better outcome after surgery. The outcome of surgical patients with putaminal or thalamic hemorrhage was no better than for those with medical treatment; however, there was a trend toward better quality of survival and chance of survival in the operated group.

Adult↗
PubMed1988

Hemorheologic treatment of cerebral reversible ischemic episodes with pentoxifylline--a prospective study.

One hundred patients (49 males, 51 females) with reversible neurologic deficit due to cerebral ischemia of vascular origin in the carotid artery territory were recruited for a long-term observation to follow up recurrence of ischemic events. Fifty-eight patients (mean age sixty-four years) were treated daily with 1200 mg oral pentoxifylline in addition to basic therapy (antihypertensives, antidiabetic drugs, etc), and 42 matching patients (mean age sixty-two years) of a control group had no pentoxifylline or other hemorheologic medication. The mean observation period was fifty-six months (range thirty-six to sixty). On admission patients presented with increased platelet aggregation and/or impaired red cell filterability and with enhanced red cell aggregation. Five patients in the pentoxifylline group (8.6%) and 16 control patients (38%) suffered a relapse of an ischemic episode. These data support previous reports of a beneficial effect of pentoxifylline in the prevention of cerebral ischemic events.

Aged↗
PubMed1988

[Rolandic spikes as an electroencephalography manifestation of oligodendroglioma].

A 10 5/12 year old boy was presented with seizures of uncertain origin on to the psychosomatic ward of our University Children's Hospital. The question and problem was the distinction of psychogenic versus epileptogenic origin (repeatedly performed EEG's had shown normal findings, the seizures did not response to anticonvulsive therapy). The exploration of a psychodynamic causes of the presenting problem was excluded by family therapeutic and psychoanalytical case history and psychodynamic interview. The first pathological finding was seen with registration of a long term EEG with typical findings of temporal central spikes and waves as seen in the benign rolandic-epilepsia. The following diagnostic considerations were discussed and differentiated. a) benign rolandi epilepsia b) malign rolandi epilepsia c) psychomotoric seizures d) rolandic spikes as symptomatic finding of a brain tumor. The definite diagnosis was finally confirmed by a cerebral computer-tomography which showed a large expensive process in the interferior right regio temporalis, which was identified histologically after operation as a oligodendrogliom grad-I. The tumor was removed successfully as a whole without any neurological defects.

Brain Neoplasms↗
PubMed1987

[Testing the regulation mechanism in inserting an artificial heart by model simulation].

The problems of controlling the cardiac output and the balance of the blood volumes in the circulatory system were discussed for the natural heart as well as for an implanted artificial heart by means of a mathematical function model of the human organism. The control by the Starling mechanism (right atrial pressure) can adapt sufficiently the cardiac output according to the demands of the body, in case the loading steps do not exceed a fixed limit. The false regulation by a strong load of the organism is evidently caused by the limited capacity of the artificial heart and not by the strategy of the control.

Cardiac Output↗
PubMed1987

[Validity of the arteriovenous oxygen difference as guidance for controlling the output of an artificial heart].

The possibility of controlling an artificial heart by the arteriovenous oxygen difference is discussed by means of the model simulation of the human organism. The simulation results are compared with these of the control by the Starling mechanism. No improvement of the results was obtainable because the behaviour of the arteriovenous oxygen difference is very dependent on the kind and the ascent of the load. The control of the artificial heart by the Starling mechanism appeared more favourable also on changed conditions in the atrium.

Blood Volume↗
PubMed1987

[Simulation of a regulation mechanism in inserting an artificial heart, by which the left and right pumps require the same output volume].

The problems of balance of the blood volume in the circulatory system are demonstrated in the application of an artificial heart by means of a mathematical function model of the human organism. The lung is endangered specially in case the right pump brings more than the left pumps away. Therefore a suitable controller was selected: it guarantees the equal output of the right and left pump. A PI-controller was used, because the complete abolition of the control deviation is more important than the dynamics. Variants were discussed about the arrangement of this controller in the total control of the artificial heart.

Blood Volume↗