Search PubMed⌕ Search

Biomedical subjects

C Trenkwalder

Publications and source records attributed to C Trenkwalder.

9 recordsLinked to original sources
PubMed1992

Apomorphine test for dopaminergic responsiveness in patients with previously untreated Parkinson's disease.

We prospectively examined the predictive value of the apomorphine test for the therapeutic efficacy of sustained oral levodopa treatment in 62 patients with de novo Parkinson syndrome (no additional neurological deficit) who had not previously been treated with dopaminergic medication. Patients received 2 to 5 mg of apomorphine hydrochloride subcutaneously and a subsequent trial of oral levodopa of at least 3 months' duration. In three patients, response to apomorphine could not be evaluated owing to side effects experienced during the test. In the remaining 59 patients, the best predictor of response to oral levodopa was the apomorphine-induced relative decrease in the scores on the motor examination part of the Unified Parkinson Disease Rating Scale (UPDRS). At a cutoff value of 20% improvement in UPDRS scores, the test predicted the response to levodopa correctly in 50 patients (85%). The sensitivity of the test was 90%, specificity 88%. The positive predictive value was 95%. However, seven of 19 apomorphine test-negative patients experienced a good (n = 4) or partial (n = 3) improvement with levodopa therapy. Thus, the negative predictive value was only 63%. We conclude that response to apomorphine has a high predictive value for response to sustained oral levodopa treatment in most previously untreated patients, but a negative test should not preclude an adequate trial of oral levodopa.

Adult↗
PubMed1992

Decrease of D2 receptors indicated by 123I-iodobenzamide single-photon emission computed tomography relates to neurological deficit in treated Wilson's disease.

Single-photon emission computed tomography with 123I-iodobenzamide, a dopamine D2 receptor antagonist, was employed to study dopamine D2 receptor densities in 17 patients with biochemically proved Wilson's disease and stable neurological status with therapy and in 5 age-matched control subjects. Of the 17 patients with Wilson's disease, 5 were neurologically asymptomatic, 3 had cerebellar signs, 1 exhibited a mild parkinsonian syndrome, 7 showed a parkinsonian syndrome and cerebellar signs, and 1 had generalized dystonia and a parkinsonian syndrome. In 5 age-matched control subjects specific isotope binding as calculated by the basal ganglia to frontal cortex ratio was 1.57 +/- 0.04 (mean +/- standard deviation). The ratio in patients with Wilson's disease ranged from 1.56 +/- 0.05 (n = 5, asymptomatic patients) to 1.17 +/- 0.02 (n = 4, marked neurological impairment). We observed an almost linear correlation between the reduction of 123I-iodobenzamide (IBZM) binding and the severity of neurological signs at the time of IBZM-SPECT (correlation coefficient, -0.84; p < 0.01). We suggest that the reduction of postsynaptic striatal dopamine D2 receptors as detected by IBZM-SPECT reflects striatal neuronal damage in Wilson's disease.

Adolescent↗
PubMed1992

Marked reduction of striatal dopamine D2 receptors as detected by 123IBZM-SPECT in a Wilson's disease patient with generalized dystonia.

[123I]iodobenzamide-single photon emission computed tomography (IBZM-SPECT) was employed to study the distribution of dopamine D2 receptors in a patient with biochemically proven Wilson's disease presenting with generalized dystonia. IBZM is a dopamine D2 receptor antagonist with high affinity and specific binding to basal ganglia detectable by SPECT. IBZM-SPECT in this patient (age, 20 years) displayed a striatum to frontal cortex ratio of 1.2 compared to 1.55 +/- 0.05 (mean +/- SD) in normal controls (n = 7; mean age, 53.3 years). In parallel with this finding, MRI with heavily T2-weighted sequences showed atrophy and low signal intensity changes of the basal ganglia. There was no improvement of dystonia after a subcutaneous injection of apomorphine. In contrast, IBZM-SPECT of a neurologically asymptomatic Wilson's disease patient (age, 21 years) displayed a striatum to frontal cortex ratio of 1.6. The MRI scan of this patient was normal. It is suggested that the observed apomorphine-unresponsive generalized dystonia in this Wilson's disease patient is related to striatal lesions proven by IBZM-SPECT and MRI.

Adult↗
PubMed1992

Postural imbalance: an early sign in HIV-1 infected patients.

We have recorded postural performance in 50 HIV-infected patients in different stages of the disease (Walter Reed (WR) stages I-VI) by means of a force measuring platform. The results were compared with 50 age-matched controls. A significant instability was particularly evident when standing on an unstable foot support. In patients standing with "eyes closed", postural sway was significantly higher in every patient group (WR I-II: P less than 0.02, WR III-V: P less than 0.001, WR VI: P less than 0.001). Patients in stage WR I-II showed no relevant neurological abnormalities. In agreement with other neurophysiological data in the literature we suggest that postural imbalance could be an early sign of central nervous system penetration of HIV. No correlation with electromyographic or cerebrospinal fluid findings could be found.

Adult↗
PubMed1992

Folinic acid therapy fails to improve early Parkinson's disease: a two week placebo controlled clinical trial.

Folinic acid (15 mg bid, po) was administered in a two week, double-blind, placebocontrolled, cross over clinical trial in 5 patients with Parkinson's disease (Hoehn and Yahr stage I or II). 4 patients had not been on L-dopa treatment prior to entering this trial and one patient was on a small dose of L-dopa. No significant improvement could be detected in this pilot study by clinical evaluation and motor performance assessed by a computer assisted motor performance test.

Adult↗
PubMed1992

123I-iodobenzamide-SPECT predicts dopaminergic responsiveness in patients with de novo parkinsonism.

We used 123I-iodobenzamide-single photon emission computed tomography (IBZM-SPECT) in a prospective study to investigate 38 patients with parkinsonism (Hoehn and Yahr stage I to III) not previously treated with dopamimetic drugs. Thirty-four patients only showed symptoms of Parkinson's disease, and four patients showed, in addition, subtle clinical signs of progressive supranuclear palsy or multisystem atrophy. IBZM is a dopamine D2 receptor antagonist detectable by SPECT. We compared IBZM-SPECT results with clinical response to subcutaneous injections of the D1/D2 dopamine receptor agonist apomorphine (38 patients) and long-term dopamimetic therapy (31 patients). IBZM-SPECT results predicted a positive or negative response to apomorphine in 30 of 34 patients (apomorphine response in four patients was equivocal) and response to dopamimetic therapy in 27 of 31 patients. Thus, imaging of dopamine D2 receptors using readily available IBZM-SPECT seems to distinguish between L-dopa-responsive (most likely Parkinson's disease of Lewy body type) and L-dopa-unresponsive parkinsonism in patients not previously treated with dopamimetic drugs.

Adult↗
PubMed1991

[Neurogenetics--the challenge for neurology. 1. Neurogenetic diseases].

Progress in molecular genetics has provided insight into a number of neurogenetic disorders. The chromosomal location of the genes for Huntington's disease, Wilson's disease, myotonic dystrophy and Friedreich's ataxia are now known. In families affected by these illnesses, linkage analysis can now be employed for presymptomatic or prenatal diagnosis. The genes for Duchenne and Becker muscular dystrophy and neurofibromatosis I have been cloned and sequenced, allowing the direct analysis of the genetic defect in many cases, and thereby providing further insight into the pathophysiology. In addition, the classification of several neurogenetic diseases, such as the hereditary motor and sensory neuropathies or the spinal muscular atrophies can now be based on the chromosomal location of the affected gene(s).

Chromosome Mapping↗
PubMed1990

Reduced cerebral blood flow in early stages of human immunodeficiency virus infection.

In order to determine if brain perfusion abnormalities, which are known in patients with acquiredimmunodeficiency syndrome dementia, occur in early stages of human immunodeficiency virus infection, technetium 99m hexamethyl-propyleneamine oxime-single-photon emission computed tomography studies were performed in 20 patients infected with human immunodeficiency virus who belonged to Walter Reed stages I through IV. None of these patients demonstrated signs of dementia or severe neurological dysfunction. Pathological patterns of hexamethyl-propyleneamine oxime uptake were seen in 14 patients, seven of whom had normal results during neurological examination. Only four patients had signs of cerebral atrophy on cranial computed tomographic scan. These data suggest that subtle changes in cerebral perfusion seem to arise early in the course of human immunodeficiency virus infection and may indicate human immunodeficiency virus encephalopathy before neurological symptoms or noticeable structural damage occurs.

Acquired Immunodeficiency Syndrome↗