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Biomedical subjects

K Kunze

Publications and source records attributed to K Kunze.

At least 37 records · Page 2Linked to original sources
PubMed1997

Missense mutation (R15W) of the connexin32 gene in a family with X chromosomal Charcot-Marie-Tooth neuropathy with only female family members affected.

A small family with sensorimotor neuropathy of dominant inheritance was examined. All three affected members were female. They had unusually severe symptoms and pronounced reduction of motor nerve conduction velocities with absent sensory nerve action potentials. Molecular genetic analysis disclosed a missense mutation in the connexin32 gene in codon 15 (Arg15Trp) which predicts the replacement of a basic amino acid to a non-polar amino acid in the first cytoplasmic loop of the protein. This report illustrates that in small pedigrees in which only women are affected, and which show a severe clinical phenotype, X chromosomal Charcot-Marie-Tooth neuropathy should be considered as differential diagnosis.

Alleles↗
PubMed1997

Glucocorticoids and anabolic/androgenic steroids inhibit the synthesis of GABAergic steroids in rat cortex.

Cerebral side effects of therapy with glucocorticoids include mental alterations and behavioral disturbances such as nervousness, insomnia, changes in mood or psychological state and psychopathies of manic-depressive or schizophrenic type. We have investigated the effects of glucocorticoids, anabolic/androgenic steroids and the 5-alpha-reductase inhibitor N,N-bis (1-methyl)-3-oxo-4-aza-5-alpha-androstane-17-beta-carboxamide (1-MAC) on the synthesis of the GABAergic steroids 5-alpha-pregnane-3.20-dione (5-alpha-dihydroprogesterone) and 5-alpha-pregnane-3-alpha-ol-20-one (5-alpha-tetrahydroprogesterone) in rat cortex in vitro. We found potent inhibition of progesterone-3-alpha-hydroxysteroid dehydrogenase (3-alpha-HSDH) by prednisone, prednisolone, dexamethasone and fluocortolone. Inhibition of progesterone 5-alpha-reductase by glucocorticoids was not found. In addition, inhibition of 3-alpha-HSDH and 5-alpha-reductase by androgenic/anabolic steroids and inhibition of 5-alpha-reductase by 1-MAC could be demonstrated. The inhibition of progesterone metabolism in the cerebral cortex by exogenous steroids might lead to altered neuronal activity. We conclude that this mechanism could induce the cerebral side effects, such as mental modifications and behavioral disturbances, of the drugs investigated.

Animals↗
PubMed1996

Long-term management of acute respiratory failure in metabolic myopathy.

OBJECTIVE: To describe how patients cope with the proposal of treatment with intermittent artificial ventilation after acute respiratory failure due to progressive respiratory muscle weakness. DESIGN: Case series, follow-up study. SETTING: Neurological intensive care unit (ICU). PATIENTS: 7 consecutive patients with metabolic myopathy treated for acute respiratory failure between 1983 and 1992. INTERVENTIONS: Intermittent positive pressure ventilation (IPPV) via tracheostomy. MEASUREMENTS AND RESULTS: Symptoms of chronic hypoventilation preceded acute respiratory failure for months. With one exception, patients were mainly disabled from respiratory muscle weakness and sleep-related breathing disorders. IPPV was recommended to prevent recurrent respiratory failure. Two of three patients who accepted home IPPV returned to full-time jobs. One patient, who decided against IPPV, died from CO2 narcosis several months after discharge. All patients adhered to the respiratory regimen once instituted. CONCLUSIONS: Acute respiratory failure in chronic myopathy is heralded by daytime drowsiness. IPPV, or at least regular monitoring of waking and sleeping partial pressure of carbon dioxide, is highly recommended even if weaning is successful. IPPV improved quality of life. The treatment strategy at discharge from the ICU should be optimal, as patients are reluctant to modify regimens.

Activities of Daily Living↗
PubMed1996

[Acute reversible encephalopathy with brain edema and serial seizures in pseudohypoparathyroidism].

A 16 year old patient with the typical clinical signs of Albright's hereditary dystrophia developed series of epileptic seizures with loss of consciousness, tonic muscle contractions and bite of the tongue. After termination of the seizures there was coma without focal neurological signs. CT scan revealed diffuse brain edema. Electroencephalographic studies showed generalized slowing. In laboratory tests the only abnormalities were marked hypocalcemia (1.15 mmol/l) and hyperphosphatemia. Blood parathyroid hormone (PTH) was elevated. PTH-Test confirmed the diagnosis of pseudohypoparathyroidism. The patient was treated with calcium and 1,25-dihydroxy-cholecalciferol. After few days the severe encephalopathy, CT and electroencephalographic changes were completely reversible. Hereditary disturbances of the parathyroid hormone metabolism are rare diseases. Hypocalcemia must be included into the differential diagnosis of seizures and brain edema to avoid invasive diagnostic and irrational treatment.

Adolescent↗
PubMed1996

Recovery from brain-stem lesions involving the nociceptive pathways: comparison of clinical findings with laser-evoked potentials.

Dissociated sensory impairment in brain-stem disorders suggests a lateral lesion involving the spinothalamic tract. Evoked potential studies of the somatosensory system with standard electrical stimulation (SEP) generally fail to establish objective correlates of such sensory deficits, because electrical stimuli predominantly activate large myelinated fibers that project into the medial lemniscal system. In contrast, laser-evoked potentials (LEPs), in response to brief radiant heat pulses, stimulate nociceptive afferents of the superficial skin and allow evaluation of thin fiber and spinothalamic tract function. We describe the recovery of deficits in pain sensitivity in five patients with isolated lateral brain-stem lesions that could be successfully monitored by LEP recordings in the acute stage and after intervals ranging from 7 months to 4 years. Upon first examination, LEPs were abnormal on the affected body side in all five cases of lateral medullary syndrome, irrespective of whether the etiology was vascular or inflammatory. The degree of recovery of pain sensitivity upon reexamination was reflected by the extent of normalization of the LEP. A control patient with vascular pontine lacunar stroke had normal LEPs on both sides, suggesting preserved spinothalamic conduction. The peak-to-peak amplitude of the main LEP component (N250-P400) correlated significantly with clinical pain sensitivity scored by standardized sensory testing (r = 0.76, p < 0.01). In contrast, early and late SEPs, after standard electrical median or tibial nerve stimulation, were normal in all patients, consistent with their intact mechanosensitivity. In conclusion, LEP studies allow the status of nociceptive function to be objectively and reliably documented on repeated examinations and therefore provide a useful supplement to multimodal sensory assessment in brain-stem disorders.

Adult↗
PubMed1996

Sensory deficits of a nerve root lesion can be objectively documented by somatosensory evoked potentials elicited by painful infrared laser stimulations: a case study.

Somatosensory evoked potentials (SEPs) in response to painful laser stimuli were measured in a patient with a unilateral sensory deficit due to radiculopathy at cervical levels C7 and C8. Laser evoked potentials (LEPs) were compared with SEPs using standard electrical stimulation of median and ulnar nerves at the wrist and mechanical stimulation of the fingertips by means of a mechanical stimulator. Early and late ulnar and median nerve SEPs were normal. Mechanical stimulation resulted in w shaped early SEPs from all five fingertips with some degree of abnormality at the fourth and fifth digits of the affected hand. Late LEPs were completely absent for stimulations at affected dermatomes and normal in the unaffected control dermatomes. The border between skin areas with normal or absent LEPs was very sharp and fitted the dermatomes of intact C6 and damaged C7 and C8 nerve roots. It is suggested that pain dermatomes are narrower than tactile dermatomes because thin fibres of the nociceptive system, activated by laser stimuli, probably do not overlap between adjacent spinal segments to the same extent as thick fibres of the mechanoreceptive system, activated by standard electrical or mechanical stimulation.

Aged↗
PubMed1996

Reversible dementia in idiopathic hypoparathyroidism associated with normocalcemia.

Dementia in idiopathic hypoparathyroidism is generally ascribed to hypocalcemia and improves following normalization of the serum calcium level. We report a 51-year-old man with severe dementia and hypoparathyroidism, but without serum hypocalcemia and without clinical signs of hypocalcemia. There was rapid and sustained improvement and normalization of symptoms after therapy with 1,25-dihydroxy-cholecalciferol. We conclude that hypocalcemia is not the sole cause of dementia in idiopathic hypoparathyroidism.

Calcium↗
PubMed1995

Limited value of cerebrospinal fluid for direct detection of Toxoplasma gondii in toxoplasmic encephalitis associated with AIDS.

The diagnosis of acquired immunodeficiency syndrome-associated toxoplasmic encephalitis (TE), a typically focal disease resulting from reactivation of tissue cysts, relies mainly on indirect diagnostic methods. In a prospective study, we investigated the value of detection of Toxoplasma gondii in cerebrospinal fluid (CSF) by using the polymerase chain reaction and the mouse inoculation test. Twenty-four patients with 26 episodes of TE, 2 HIV-infected patients with primary acute Toxoplasma infection, and 38 HIV-infected control patients with latent Toxoplasma infection were investigated. Detection of T. gondii in CSF by both methods was possible in only 3 of the TE patients (11.5%), the remaining patients being negative with either of the methods. In contrast, T. gondii DNA was detected in both of the acutely infected patients, indicating that in primary acute toxoplasmosis parasites may easily be found in the CSF, whereas in the majority of TE cases in immunocompromised patients, T. gondii parasites do not gain access to the CSF drawn by lumbar puncture.

AIDS-Related Opportunistic Infections↗
PubMed1995

Discriminant classification of motor unit potentials (MUPs) successfully separates neurogenic and myopathic conditions. A comparison of multi- and univariate diagnostical algorithms for MUP analysis.

Multivariate statistical methods may be more appropriate for the multidimensional material of quantitative motor unit potential (MUP) analysis than the multiple univariate tests of the conventional Buchthal analysis. Buchthal analysis was slightly modified before it was used as the gold standard for new multivariate diagnostical algorithms, based on principal component analysis and on MUP discriminant classification: muscle means of continuous variables were related to tolerance limits after adequate transformation. Chi-square tests were used for dichotomized variables, e.g., polyphasia. Sensitivity and specificity of the uni- and multivariate algorithms were compared for 539 muscles from patients with motor neuron diseases, neuropathies and myopathies and for 91 biceps brachii, rectus femoris and tibialis anterior control muscles. False positive results accumulated less than expected by repeat univariate tests for single MUP parameters, due to high correlation. Combination of single parameters to factor scores did not improve specificity. One advantage of factor analysis was that factor matrix and factor scores matched those of previous studies in spite of different input parameters, which may facilitate multicenter comparisons. Discriminant classification successfully separated neurogenic and myopathic conditions, even in myositic muscles and motor neuron diseases, where myopathic and neuropathic MUPs frequently intermingle. Discriminant classification may support expert decisions and add weight to EMG differential diagnosis.

Adult↗
PubMed1995

[Does a neurologic clinic need an inhouse cerebrospinal fluid/neurochemical laboratory? Results of a survey of 289 neurological clinics].

In 1993 and 1994 an official inquiry was carried out by the Deutsche Gesellschaft für Neurologie into the existence of neurochemical laboratories in departments of neurology throughout Germany. The following results were obtained. Neurochemical laboratories are more often seen in neurology departments involved in routine or emergency diagnosis than in departments engaged only in rehabilitation. Nearly all departments with an intensive care unit in a university hospital (91%) and nearly half of those outside the university (46%) have their own neurochemical laboratory. Departments with their own neurochemical laboratories are characterized by the use of specialized immunological diagnosis, especially of the cerebrospinal fluid (e.g., immunoglobulins, isoelectric focusing), in contrast to departments that are not working in the field of emergency medicine and are not equipped with their own neurochemical laboratories. The latter mostly carry out screening tests (e.g., antiepileptic drug monitoring, tumor markers). The existence of a neurochemical laboratory in a neurology department does not lead to an undifferentiated increase in the number of laboratory tests, but reflects the need for specialized diagnosis in CSF and neuroimmunology.

Brain Chemistry↗
PubMed1994

[Comparative studies of synthetic and nonsynthetic cast dressings].

Six different cast materials were evaluated and compared for radiolucency and mechanical properties. Synthetic casts, that do not contain fiberglass are more radiolucent than fiberglass cast materials or plaster of Paris. The fiberglass cast is particularly stable, and the advantage of the cotton cast is a low dead weight. The costs of synthetic casts made according to the producer manufacturers' recommendations do not differ significantly, but they are all much more expensive than plaster of Paris. Splitting a synthetic cast along its length and bending it open is not enough to prevent compartment syndrome, and wedging is recommended to keep it open.

Absorptiometry, Photon↗
PubMed1993

Wilson's disease with cerebral manifestation: monitoring therapy by CSF copper concentration.

The clinical courses, cerebrospinal fluid (CSF) and serum copper concentrations and urinary copper excretions under different schemes of drug treatment in four patients with cerebral manifestations of Wilson's disease were monitored over 6-11 years. CSF copper concentration measurements were performed from the beginning of therapy onwards in three patients and from 16 months after initial treatment onwards in the fourth. CSF copper levels decreased slowly over the years in parallel with clinical improvements, and increased in one patient who interrupted therapy for 2 years. These findings confirm our hypothesis that the concentration of copper in the CSF is a valuable quantitative parameter reflecting the normalization of copper in the brain. Copper measurements during phases of initial neurological deterioration in two patients receiving D-penicillamine, and in one patient receiving D-penicillamine and zinc sulphate, revealed decreased free serum copper and CSF copper levels.

Adult↗
PubMed1993

Frequency analysis and duration of motor unit potentials: reliability and diagnostic usefulness.

We studied the correlation, reliability and diagnostic usefulness of different time and frequency parameters of motor unit potentials (MUPs). Most frequency parameters were redundant because of high correlation with conventional MUP parameters. Variable selection algorithms for discriminant analysis indicated that center frequency (CENTFR) and spike duration (SPD) improved the discrimination between MUPs from normal, myopathic and neuropathic muscles. This was corroborated by univariate statistical tests comparing mean MUP duration (DUR), mean CENTFR and mean SPD of pathological muscles with those of normal muscles. One-sided tests for increased mean SPD improved the sensitivity for neurogenic changes and one-sided tests for reduced mean CENTFR improved the sensitivity for myopathic changes. The rate of false positive results did not increase by these additional tests. The retest reliability of CENTFR was superior to that of DUR. CENTFR and SPD are recommendable new parameters for quantitative MUP analysis based either on multi- or univariate statistics.

Action Potentials↗
PubMed1993

[The diagnosis of inflammatory muscular and vascular diseases using MRT with STIR sequences].

The role of MRT in the prebiopsy diagnosis of muscular and vascular inflammatory conditions was evaluated prospectively and an optimal method of examination was investigated. 92 patients with a suspected diagnosis of myositis (60 cases) or vasculitis (32 cases) were examined, in each case two extremities were studied using transverse T1 and T2 weighted SE sequences and double echo STIR sequences on a 0.5 Tesla (56 patients) or 1.5 Tesla magnet (36 patients; T5/S15 Gyroscan, Philips). The site of the biopsy depended on the MRT findings. In 41 patients the suspected diagnosis was confirmed histologically, in two patients an infective myositis was diagnosed on clinical grounds despite negative histology. MRT demonstrated muscle oedema in 86% of patients. There were negative findings after immuno-suppressive therapy (two patients), in focal myositis (3 out of 4 patients) and in one of 7 patients with untreated vasculitis. Amongst 49 patients in whom the suspected diagnosis could not be confirmed there was muscle oedema in 11 cases (9 neuropathies out of 22, two myopathies out of 10). Oedema indicated inflammatory muscular or vascular disease with a sensitivity of 97% (except in treated patients and for focal myositis). The number of false negative biopsies can be greatly reduced by the use of MRT.

Adult↗