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Biomedical subjects

K Reiners

Publications and source records attributed to K Reiners.

At least 19 recordsLinked to original sources
PubMed1999

Vulnerability of the nigrostriatal system as detected by transcranial ultrasound.

OBJECTIVE: To assess the incidence of a hyperechogenic substantia nigra (SN) by transcranial sonography (TCS) in healthy people and to evaluate whether an enlarged hyperechogenic SN area is associated with functional impairment of the nigrostriatal system. BACKGROUND AND METHODS: Until now, preclinical impairment of the nigrostriatal system could be identified only by functional neuroimaging techniques such as PET in selected groups of patients. TCS is a new, noninvasive ultrasound technique that has demonstrated an increased echogenicity of the SN in patients with PD, whereas in most healthy individuals, the SN is either barely detectable or undetectable by TCS. RESULTS: Of 330 healthy volunteers, 8.6% exhibited an increased echogenicity of the SN. From these, 10 clinically healthy individuals with distinct unilateral or bilateral hyperechogenic signals in the SN region (SN area above 0.25 cm2) underwent comprehensive motor testing, neuropsychological assessment, MRI, and [18F]-dopa PET examination. With regard to motor functions, these individuals did not differ from 10 age- and sex-matched controls with a low echogenic SN and an area of echogenic signals below 0.2 cm2. Enlargement of hyperechogenic areas in the 10 healthy individuals was associated with a marked decrease in the accumulation of [15F]-dopa in the caudate nucleus and putamen. CONCLUSIONS: Substantia nigra hyperechogenicity appears to indicate a functional impairment of the nigrostriatal system. Transcranial sonography may be a suitable method of identifying persons at risk of nigrostriatal alterations, making possible the introduction of early neuroprotective therapy.

Adolescent↗
PubMed1999

Twenty-four-hour heart rate power spectrum for evaluation of autonomic dysfunction in Guillain-Barré syndrome.

Long-term fluctuations of the heart rate have an important prognostic impact after myocardial infarction, in patients with chronic heart failure and even in elderly subjects. Autonomic dysfunction is a common complication in patients with Guillain-Barré syndrome, and particularly vagally-mediated bradyarrhythmias require early recognition for immediate initiation of appropriate preventive therapy. This study aimed at investigating (1) whether the 24-h heart rate power spectrum (HRPS) could be used as a measure of autonomic dysfunction also in patients with GBS, and (2) whether the slope of the regression line of power on frequency of the 24-h HRPS could indicate potentially fatal bradyarrhythmias in these patients. In 13 patients with GBS, the heart rate was continuously recorded in the intensive care unit during the early stages of the disease, averaged at 1-min intervals and stored for 4 to 82 days. The HRPS (n = 76, 2 to 14 per patient, median 5) was calculated by Fourier analysis of 24-h recordings and logarithmically transformed. The slope was estimated by regression analysis of log(power) on log(frequency) between 10(-4) and 4x10(-3) Hz demonstrating an inverse power law behaviour in all 76 HRPS. The slope of the regression line ranged from -0.66 to -2.18, and was significantly steeper in patients with tachycardia (median -1.51, interquartile range -1.35 to -1.71) than in those with vagal overreactivity (median -1.14. -1.02 to -1.23) who are suspected to be at risk for fatal arrhythmias. Correlation analysis suggested that the slope was moderately associated with the spectral components of 5-min epochs, but not significantly to standard tests of autonomic hypofunction. Patients with and without vagal overreactivity were better discriminated by the 24-h HRPS than by conventional measures of autonomic function. Therefore, the 24-h HRPS may be a useful adjunct to autonomic nervous system testing, and might be a promising tool to predict serious bradyarrhythmias in patients with GBS.

Adult↗
PubMed1999

Increased tissue copper and manganese content in the lentiform nucleus in primary adult-onset dystonia.

We analyzed trace metals in frozen brain tissue of several subcortical nuclei from 3 patients with primary adult-onset dystonia and 10 control subjects. Copper levels were significantly increased in the globus pallidus and putamen of patients with dystonia A slight increase in manganese content was identified in the putamen and thalamus of patients with dystonia. Our findings show for the first time an accumulation of trace metals in the lentiform nuclei in patients with primary dystonia, which may play a pathogenetic role in primary dystonia and may explain recent ultrasound and magnetic resonance imaging findings.

Age of Onset↗
PubMed1999

Cardiovascular autonomic dysfunction in multiple sclerosis: correlation with orthostatic intolerance.

Autonomic dysfunction is frequently observed in patients with multiple sclerosis (MS), but clinical studies disagree on the frequency and type of abnormalities in autonomic function tests. Orthostatic dizziness (OD) has been reported in up to 49% of patients, but the pathophysiological mechanisms are poorly understood. This study investigated cardiovascular reflex tests and their association with OD in patients with MS in order to examine the hypothesis that the sympathetic nervous system is specifically involved in these patients. Forty patients with clinically active relapsing-remitting (n = 27) and secondary progressive MS (n = 13), aged 35.0+/-8.5 years, were studied by parasympathetic (heart rate responses to the Valsalva maneuver, deep breathing, and active change in posture) and sympathetic function tests (blood pressure responses to active change in posture and sustained handgrip), and by spectral analysis of heart rate variability during rest and during standing. Results were compared to those obtained in 24 healthy volunteers, aged 29.4+/-7.2 years. A standardized questionnaire was used to evaluate symptoms of orthostatic intolerance. Abnormal responses on at least one cardiovascular reflex test were observed in 40% of MS patients, compared to 17% of the control group, with a statistically significant involvement of the sympathetic vasomotor system. Orthostatic intolerance was reported in 50% of patients (controls: 14%, P<0.006). Subgroup comparison of patients with and without OD suggests that orthostatic intolerance results from impaired sympathetic vasoconstriction. These results provide further evidence that the sympathetic nervous system is involved in patients with MS.

Adult↗
PubMed1999

[Diabetic neuropathies. Basic principles, clinical manifestations and drug therapy].

Neuropathy is a serious complication in diabetes mellitus. It presents in a variety of clinical manifestations and is an essential precondition for the development of the diabetic foot syndrome. While the common distal symmetrical sensorimotor form of diabetic neuropathy cannot be clinically differentiated from neuropathies of other etiologies, the less common focal forms of diabetic neuropathy require the differential diagnosis from other localized disorders. In most patients diabetic neuropathies can be diagnosed on clinical grounds. Early recognition is important, and intensive glycemic control is paramount in all therapeutic efforts.

Diabetic Foot↗
PubMed1998

Focal hyperhidrosis: effective treatment with intracutaneous botulinum toxin.

OBJECTIVE: To evaluate the effect of intracutaneous injections of botulinum toxin type A on excessive focal hyperhidrosis. DESIGN: Therapeutic before-and-after trial over 4 months. SETTING: Neurological and dermatological university departments. PATIENTS: Eleven patients with excessive axillary, palmar, or plantar hyperhidrosis fulfilling the following criteria: (1) local and systemic drug therapy had failed to improve their symptoms; (2) the patients were severely disabled with respect to their occupation and social activities; and (3) a successful treatment by botulinum toxin would obviate the need for destructive surgical procedures. INTERVENTIONS: Three mouse units of botulinum toxin (Botox) per 4-cm2 skin area was injected intracutaneously in 16 axillae, 8 palms, and 2 soles. MAIN OUTCOME MEASURES: Reduction of hyperhidrosis as documented by the Minor iodine-starch test and gravimetrical assessment of local spontaneous sweat production measured over 1 minute. RESULTS: In all patients, botulinum toxin completely abolished sweating in the injected areas (P<.001) within 3 to 7 days. No relevant adverse effects occurred and no clinical recurrence of hyperhidrosis was observed within the follow-up period of up to 5 months. Occasionally, subclinical reactivation of sweat gland function was observed 4 months after treatment. CONCLUSIONS: Intracutaneous botulinum toxin seems preferable to any hitherto used conservative or surgical procedures and may become the therapy of choice in pathological focal hyperhidrosis.

Adult↗
PubMed1998

Imaging the pre- and postsynaptic side of striatal dopaminergic synapses in idiopathic cervical dystonia: a SPECT study using [123I] epidepride and [123I] beta-CIT.

There is increasing evidence that a dysfunction of the dopaminergic system may be involved in the pathogenesis of idiopathic dystonia. To visualize possible alterations of the pre- and postsynaptic side of striatal dopaminergic synapses, SPECT studies using the radiotracers [123I] epidepride and [123I] beta-CIT were performed in 10 patients with idiopathic cervical dystonia. Eleven age- and sex-matched subjects served as controls. [123I] Epidepride is a new highly affine marker of D2 receptors, and [123I] beta-CIT binds to dopamine transporters on dopaminergic nerve endings. [123I] Epidepride binding was significantly reduced in both striata of dystonia patients compared with controls (p < 0.05). In contrast, striatal [123I beta-CIT uptake did not differ from controls. We conclude that dopaminergic dysfunction in idiopathic focal dystonia mainly involves postsynaptic mechanisms and suggest a disturbance of the indirect pathway of the motor circuit resulting in a disinhibited thalamocortical stimulation.

Adult↗
PubMed1998

1H magnetic resonance spectroscopy of the lentiform nucleus in primary focal hand dystonia.

Several radiologic findings point toward the lentiform nucleus as a possible site of lesion in primary dystonia. Histologic examinations, however, have shown inconsistent results. 1H-magnetic resonance spectroscopy (MRS) has proved helpful to assess neuronal degeneration in a variety of basal ganglia disorders. MRS data of dystonia patients are, however, lacking so far. 1H-MRS centered on the lentiform nuclei was performed in 14 patients with primary focal hand dystonia and in 12 healthy control subjects using a 1.5-T MR imager. No statistically significant differences of N-acetylaspartate/creatine and lactate/creatine ratios were found between patients and control subjects. Based on these data, the authors found no evidence that primary focal dystonia was associated with a conspicuous loss of lentiform nucleus neurons or a marked disturbance of the aerobic metabolism, although minor abnormalities cannot be excluded because of the possibly limited sensitivity of the method.

Adult↗
PubMed1998

Acute transverse myelitis in childhood: nine cases and review of the literature.

Acute transverse myelitis (ATM) is a rare disease in childhood and adolescence. It is characterized by paraplegia with or without sensory symptoms and bladder dysfunction, and typically manifests itself over a period of hours to 1 week. This is a report of nine patients who were treated between 1993 and 1996. To exclude treatable conditions, spinal and cranial MRI with and without contrast medium, electrophysiologic tests, and CSF examinations are performed as soon as possible after onset. At present post- or parainfectious inflammation is thought to be the most frequent cause of ATM. Some causes of ATM can be proved only by follow-up examination. The most important differential diagnoses are multiple sclerosis and Guillain-Barré syndrome with its variants. After exclusion of spinal cord compression, and if specific antibiotic treatment is not possible, a 3-day high-dose i.v. steroid pulse therapy is the most promising treatment. Prognosis is variable and residual symptoms are common. A controlled multicenter study is suggested to assess epidemiology, etiology, and prognosis of ATM.

Acute Disease↗
PubMed1998

Man-in-the-barrel syndrome caused by cervical spinal cord infarction.

Acute brachial diplegia with normal findings of the legs, "man-in-the barrel" (MIB) syndrome, is generally thought to be caused by bilateral supratentorial brain lesions of the prerolandic cortical and subcortical area. We report 1 patient with a sudden onset of MIB syndrome with no supratentorial lesion but a hemodynamically induced atypical anterior spinal cord infarction after unilateral vertebral artery dissection. Thus, in MIB syndrome an infratentorial lesion site, including the cervical spinal cord, should also be considered.

Acute Disease↗
PubMed1998

Depletion of neutralising antibodies resensitises a secondary non-responder to botulinum A neurotoxin.

The objective was to evaluate whether removal of neutralising antibodies potentially resensitises a secondary non-responder to botulinum neurotoxin A (BoNT/A). Neutralising antibodies directed against BoNT/A are produced during long term treatment with BoNT/A-hemagglutinin complex in up to 10% of patients with cervical dystonia. These patients become secondary non-responders. Other serotypes of BoNT are not yet generally available and may also bear the risk of inducing antibody formation. Plasma exchange (PE) (one treatment cycle) and immunoadsorption on a protein A column (IA-PA; three treatment cycles) was employed over 15 months to remove neutralising antibodies from a severely disabled secondary non-responder with cervical dystonia. After plasma exchange or IA-PA, BoNT/A was reinjected. Antibodies were measured with a sensitive functional toxin neutralising test. Repeated use of plasma exchange and IA-PA depleted neutralising antibodies to below the detection limit and subsequently allowed successful BoNT/A injection into dystonic muscles. No serious side effects were found related to the depletion of IgG. In conclusion PE or IA-PA performed before BoNT/A readministration may provide an alternative strategy in treating selected secondary non-responders who are severely disabled.

Adult↗
PubMed1997

Ophthalmoplegia plus: clinical relevance of magnetic resonance tomogaphy findings.

The diagnostic value of magnetic resonance imaging (MRI) in patients with ophthalmoplegia plus was evaluated. Twenty patients in whom the diagnosis of opthalmoplegia plus was clinically and histochemically established underwent magnetic resonance and electrophysiological studies. Three types of neuroradiological abnormalities were found in 14 patients: (1) cerebral and/or cerebellar atrophy (n = 11), (2) hyperintense lesions of the white matter or pyramidal tract (n = 2), or (3) both (n = 1). The diagnostic yield of MRI was low, since clinically or electrophysiologically manifest lesions were missed in 4 cases and the pathological findings were non-specific, since they are seen in several demyelinating diseases. Our results suggest that MRI provides no additional information in patients with manifest ophthalmoplegia plus. We conclude that clinical presentation and evidence of ragged red fibers are the cornerstones in diagnosis of ophthalmoplegia plus.

Adult↗
PubMed1997

Quantitative assessment of cardiovascular autonomic function in Guillain-Barre syndrome.

To study the temporal course and the relationship between autonomic failure and motor weakness in Guillain-Barré syndrome (GBS), a total of 164 autonomic function tests were serially applied for up to 1 year in 13 consecutive patients. Results were compared with those obtained in 25 healthy volunteers and 13 patients with other neurological diseases. Parasympathetic function tests comprised heart rate responses to Valsalva maneuver, deep breathing, and active change of posture, whereas sympathetic vasomotor function was assessed by blood pressure responses to handgrip and standing. At the height of the disease, subclinical autonomic involvement of both parasympathetic and sympathetic arms was revealed in the vast majority of patients. Abnormalities of autonomic function tests improved gradually over time, paralleling the recovery of motor function, but were only partially related to clinically significant autonomic dysfunction. Correlation analysis suggested that tachycardia in the context of GBS might be caused by a reduction of sympathetically mediated peripheral vascular tone rather than by vagal failure.

Adult↗
PubMed1997

Treatment of gustatory sweating with botulinum toxin.

Gustatory sweating is an autonomic disorder that frequently occurs after parotid gland surgery. We investigated the action of intracutaneous injections of botulinum toxin (BTX) (1.0-2.0 mouse units/2.25-cm2 skin area) in 45 patients (mean age, 52 years) with gustatory sweating. The area of hyperhidrosis was determined by Minor's iodine test before and up to 24 weeks after the injection. The effect of BTX was assessed by measuring the hyperhidrotic area. The maximum BTX-induced reduction of gustatory sweating was seen at 7.4 +/- 4.5 days after injection. The area of sweating decreased from 17.6 +/- 8.6 cm2 before BTX to 1.3 +/- 1.6 cm2 after BTX (p < 0.0001). Half the patients rated gustatory sweating subjectively as completely abolished, and the remainder felt pronounced improvement. No toxic effects were observed. In none of the patients did hyperhidrosis recur over a 6-month follow-up. We conclude that BTX is a safe and effective treatment that can be recommended as the therapy of choice in gustatory sweating.

Adult↗
PubMed1997

Comparison of transcranial sonography, magnetic resonance imaging, and single photon emission computed tomography findings in idiopathic spasmodic torticollis.

Various lines of evidence suggest that the basal ganglia and thalamus are involved in the pathogenesis of idiopathic dystonia, but unfortunately neuroradiological and pathological data are sparse and controversial. In this study, we have examined 10 patients with spasmodic torticollis by neuroimaging techniques, including transcranial sonography (TS; n = 10), conventional (n = 10) and diffusion-weighted (n = 5) magnetic resonance imaging (MRI), and single photon emission computed tomography (SPECT; n = 10), employing [123I]iodobenzamide (IBZM) as a ligand with a high affinity to the D2 receptor. In seven patients, TS showed small hyperechogenic lesions in the medial segments of the lentiform nucleus contralateral to the side of head deviation. In accordance with the site of TS abnormalities, diffusion-weighted MRI displayed a hyperintense lesion in only one patient, while standard MRI of this area was normal in all patients. SPECT revealed a slight but statistically nonsignificant reduction of IBZM tracer uptake in an area corresponding to the dorsal portions of the striatum in 9 of the 10 patients. TS findings support the hypothesis that structural alternations of the pallidothalamic circuit contralateral to the side of head deviation are involved in the pathogenesis of idiopathic spasmodic torticollis. TS may be more sensitive in detecting basal ganglia alterations than MRI.

Adult↗