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Biomedical subjects

J D Rollnik

Publications and source records attributed to J D Rollnik.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effect of conditioning transcranial stimulation on motor evoked potentials.

Motor evoked potentials (MEPs) were recorded from extensor carpi radialis muscle in response to paired transcranial magnetic stimuli (interstimulus intervals (ISI) of 3 and 13 ms) with a test stimulus intensity of 120%. The intensity of the subthreshold conditioning stimulus ranged from 55% to 85% of the motor threshold. The threshold of intracortical inhibition (ICI: ISI--3 ms) was significantly lower than the threshold of intracortical facilitation (ICF: ISI--13 ms). The values of test MEP area at 3 ms ISI showed U-shaped dependence on the conditioning intensity while the values of test MEP area at 13 ms ISI recorded over the ICF threshold were augmented with increasing conditioning intensities. The changes of MEP latencies were polyphasic and in one and the same direction for ISIs of 3 and 13 ms. The results are suggesting a simultaneous action of ICF and ICI mechanisms.

Adult↗
PubMed2000

High frequency repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex in schizophrenic patients.

Repetitive transcranial magnetic stimulation (rTMS) has been tried therapeutically in major depression. In order to investigate the therapeutic efficacy of rTMS in psychotic patients, 12 participants (four women, eight men) with schizophrenia according to DSM-IV criteria, aged 25 to 63 years (mean (+/-s.d) 40.4+/-11.0), were enrolled in the study. Following a double-blind crossover design, patients were treated at random with 2 weeks of daily left prefrontal rTMS (20 2s 20 Hz stimulations at 80% motor threshold over 20 min, dorsolateral preforntal cortex) and 2 weeks of sham stimulation. The Brief Psychiatric Rating Scale decreased under active rTMS (p <0.05), whereas depressive symptoms (BDI) and anxiety (STAI) did not change significantly. Prefrontal rTMS might be effective in the non-pharmacological treatment of psychotic patients.

Adult↗
PubMed2000

Botulinum toxin treatment of cocontractions after birth-related brachial plexus lesions.

The authors studied botulinum toxin type A therapy of severe biceps-triceps cocontractions after nerve regeneration following birth-related brachial plexus lesions. Six children (age, 2 to 4 years) were treated two to three times over a period of 8 to 12 months with 40 mouse units of botulinum toxin at two sites of the triceps muscle. Elbow range of motion improved from 0 to 25 to 50 deg to 0 to 25 to 100 deg (p < 0.05), and muscle force of elbow flexion increased from a mean of Medical Research Council classification 1.7 to 3.7 (p < 0.05). After a 1-year follow-up, there was no clinical recurrence.

Birth Injuries↗
PubMed2000

Subthreshold prefrontal repetitive transcranial magnetic stimulation reduces motor cortex excitability.

The prefrontal cortex plays an important role in central motor control. We have examined whether prefrontal repetitive transcranial magnetic stimulation (rTMS) induces changes of motor cortex excitability determined by motor evoked potentials (MEPs) following single-pulse TMS. We studied 18 healthy volunteers stimulated at 5 Hz with 10% subthreshold prefrontal vs. occipital rTMS for 12 s. MEPs from the flexor carpi radialis muscle after single-pulse vertex stimulation were recorded during rTMS at 0, 4, 8, and 12 s. MEP areas decreased significantly after 8 s of prefrontal rTMS (P < 0. 05) but not after occipital rTMS. We conclude that rTMS of the prefrontal cortex may inhibit the primary motor areas.

Adult↗
PubMed2000

Effects of somatosensory input on central fatigue: a pilot study.

OBJECTIVE: Depression of motor evoked potentials (MEPs) following transcranial magnetic stimulation (TMS) may be a sign of central motor fatigue. As a pilot study, we have examined whether post-exercise MEP depression can be compensated by application of sensory stimuli prior to TMS. METHODS: We studied 15 healthy volunteers (aged 21-28 years) who were required to perform an exercise protocol of ankle dorsiflexion until force fell below 66% of maximum force. MEPs were recorded from the right tibialis anterior muscle. Prior to TMS, electrical stimuli were applied to the ipsilateral sural nerve with an individual interstimulus interval between 50 and 80 ms. RESULTS: MEP areas decreased after exercise. When a sensory stimulus was administered MEPs did not change. CONCLUSION: We conclude that the effects of central fatigue may be influenced by application of sensory stimuli.

Adult↗
PubMed2000

Treatment of tension-type headache with botulinum toxin type A: a double-blind, placebo-controlled study.

OBJECTIVE: To determine whether injections of botulinum toxin could be of therapeutic value in the treatment of tension-type headache. BACKGROUND: Botulinum toxin A is very effective at reducing muscle tenderness and pain in many diseases. Increased muscle tension may contribute to tension-type headache. METHODS: We performed a double-blind, placebo-controlled study with 21 patients fulfilling the International Headache Society criteria for tension-type headache. Participants were randomly assigned to treatment (pericranial injection of 10 x 20 mouse units botulinum toxin A) or placebo (injection of isotonic saline in the same manner). RESULTS: After 4, 8, and 12 weeks, no significant differences between placebo and treatment could be observed (with respect to visual analog scale, frequency and duration of headache attacks, consumption of analgesics, pressure pain threshold, total tenderness score, and quality-of-life parameters). CONCLUSIONS: The findings of our study strongly support the hypothesis that peripheral mechanisms, such as increased muscle tenderness, only play a minor role in the pathogenesis of tension-type headache.

Adult↗
PubMed2000

Low-dose treatment of cervical dystonia, blepharospasm and facial hemispasm with albumin-diluted botulinum toxin type A under EMG guidance. An open label study.

Several studies support the hypothesis that low-dose botulinum toxin treatment may be as beneficial as high-dose regimen. Therefore, we studied 115 patients (aged 27-84; mean 58.0, SD = 12.9 years; 68% females, 32% males) suffering from cervical dystonia (n = 66), blepharospasm (n = 28), and facial hemispasm (n = 21) over a period of 2 years in an open label, non-controlled pilot study. Patients received low-dose treatment with botulinum toxin type A (Dysport((R))). The toxin was diluted in 20 ml of 0.1% albumin solution to arrive at a concentration of 25 MU/ml and injected under EMG control. Patients responded to the treatment about 1 week after injection (mean 7.3 days, SD = 4.6). The mean duration of beneficial effects was 11.7 weeks (SD = 5.6). Patients evaluated the clinical global improvement on a scale ranging from 0 to 4. For the whole population, the mean was 2.7 points (SD = 1.1). In none of the subjects could antibodies to botulinum toxin type A be detected, and only a few side effects were observed. In conclusion, low-dose therapy with botulinum toxin A merits further controlled studies.

Adult↗
PubMed2000

Acamprosate reduces motor cortex excitability determined by transcranial magnetic stimulation.

Acamprosate is effective in reducing alcohol intake in weaned alcoholics. We were interested if acamprosate had an effect on the excitability of cortical motoneurons determined by transcranial magnetic stimulation (TMS). We studied 12 male healthy volunteers (mean age 29.5 years, SD = 4.8) who were either treated with 6 tablets of acamprosate (each containing 333 mg verum) per day or placebo (randomized cross-over design) for 1 week. TMS was performed after each treatment session including a paired stimulation paradigm. Motor evoked potentials (MEPs) of the placebo and verum group did not differ with respect to paired stimulation. However, motor threshold increased in the acamprosate group (verum: 61.5% (SD = 7.9) vs. placebo: 58.9% (SD = 8.8), p = 0.036). We conclude that acamprosate leads to a hypoexcitability of the motor cortex. This might be due to subcortical mechanisms, e.g. thalamocortical pathways since intracortical inhibition and facilitation was not affected.

Acamprosate↗
PubMed1999

Demyelinating sensorimotor neuropathy with congenital cataract, mental retardation, and unique, dysplastic perineurial cells within the endoneurium.

We report on a 27-year-old Caucasian female with congenital cataract and mental retardation complaining of progressive paresis and atrophy of the lower legs beginning at the age of 16 years followed by atrophy of the thighs and small hand muscles. Motor and sensory conduction velocities (CV) of the upper and lower limbs were reduced (distal peroneal nerve: 21 m/s; median nerve: motor CV: 28 m/s, sensory CV 30 m/s). In the sural nerve biopsy specimens there were unique endoneurial cells immunoreactive for antibodies against the epithelial membrane antigen with multiple surface indentations and projections considered to be dysplastic perineurial cells. To the best of our knowledge these cells have not been reported in any other type of human peripheral neuropathy. The present case with the above clinical and structural findings appears to represent a new, complex, demyelinating type of a sporadic or possibly recessively inherited motor and sensory neuropathy.

Adult↗
PubMed1999

Anxiety moderates cardiovascular responses to painful stimuli during sphygmomanometry.

Sphygmomanometry is the most common technique of blood pressure (BP) determination. We were interested in the role of anxiety as a predictor of BP changes induced by painful stimuli during sphygmomanometry. We studied 141 normotensive healthy subjects who were asked to complete a State-Trait-Anxiety-Inventory (STAI) prior to the experiment. BP was determined continuously and non-invasively using a Finapres device (Penaz-technique) and by arm sphygmomanometry. Five sphygmomanometric measurements took place, during the fourth the arm cuff was inflated to 300 mmHg (unpredictable to the subject), the others were done with a pressure of 175 mmHg. State and trait anxiety (STAI X1 and X2) correlated positively with diastolic BP changes during inflation of the arm cuff (state anxiety: r = 0.26, P < 0.05; trait anxiety: r = 0.20, P < 0.05). Our results suggest that anxiety may have an impact on cardiovascular responses following painful stimuli.

Adult↗
PubMed1998

[Change sensitivity and construct validity of the revised multi-dimensional pain scale].

PROBLEM: Assessment and evaluation of perceived pain is an interdisciplinary task. This study focused on the change sensitivity and construct validity of the German version of the Revised Multidimensional Pain Scale (MSS). METHODS: In this experiment, 72 students were assigned to one of three treatments:a) Applying a blood pressure sphygmomanometry cuff with a maximum pressure of 300 mm Hg, b) or with a maximum pressure of 175 mm Hg, c) or a control condition, applying a cuff with no pressure. During the treatment, blood pressure was continuously non-invasively measured by the Penazmethod. At the end of the experiment, the subjects worked on the revised multidimensional pain scale, on the state/trait anxiety inventory (STAI) and a Likert-scale (range 1-28) for perceived pressure. RESULTS: As expected, inflating the arm cuff induced a significant increase in pressure perception compared to the control group. However, only the subscales electrical and thermic of the MSS showed an increase across the treatment groups. No differences were found for the anxiety ratings. Correlation analysis showed that state anxiety was positively related with the subscales chronic, chemical, and thermic. Trait anxiety was related with the subscales chronic, inconvenient, and chemical. Systolic blood pressure increase was positively correlated with the subscale general of the MSS. DISCUSSION: The study shows that the MSS has a limited change sensitivity for short term pain stimuli like arm cuff pressure. Anxiety was correlated with three subscales of the MSS, indicating that perceived pain intensity assessed with the MSS is more related to emotional factors rather to the physical intensity of the arm cuff pressure.

English Abstract↗
PubMed1998

Walking and fatigue in multiple sclerosis: the role of the corticospinal system.

Transcranial magnetic stimulation was used to study motor evoked potentials (MEPs) of leg muscles in controls and patients with multiple sclerosis (MS) before and after walking. In controls, MEP areas were significantly reduced after walking. A similar or greater reduction was seen in most patients, although there was a wide range of values. The M waves were unchanged. We conclude that walking induces functional changes of the corticospinal system and/or connected neurons contributing to central fatigue, especially in patients with MS.

Adult↗
PubMed1997

Biologically active TGF-beta 1 is increased in cerebrospinal fluid while it is reduced in serum in multiple sclerosis patients.

OBJECTIVES: The polypeptide transforming growth factor-beta 1 (TGF-beta 1) is a product of activated monocytes, among other inflammatory cells, and it affects immune responsiveness, cellular growth and differentiation. TGF-beta 1 has potent T-cell inhibiting activities. It may play an important role in limiting autoimmune inflammation. We were interested about levels of biologically active and total TGF-beta 1 in serum and CSF in patients suffering from multiple sclerosis. SUBJECTS AND METHODS: We measured biologically active and total TGF-beta 1 in serum and CSF using ELISA-technique in 64 MS patients with 57 during acute exacerbation of MS and 7 in remission (primary-relapsing: n = 59; primary-progressive: n = 5), 20 healthy subjects, and 21 patients with other non-inflammatory neurological diseases (OND). RESULTS: Biologically active TGF-beta 1 in serum was reduced in MS patients compared to controls, on the other hand total TGF-beta 1 was elevated in CSF compared to patients with OND. Biologically active TGF-beta 1 in CSF correlated positively with the duration of the acute relapse in patients with primary-relapsing MS. The more relapses the patients had the higher was biologically active TGF-beta 1 in CSF. Total TGF-beta 1 in CSF correlated with macrophages in CSF and albumin quotient. CONCLUSION: We found that an elevated level of biologically active TGF-beta 1 in CSF might be useful as an indicator of disease limitation while active TGF-beta 1 in serum is reduced in multiple sclerosis. Measuring TGF-beta 1 in body fluids by ELISA techniques produces valid results and might be used for further studies focusing on the role of this cytokine in MS.

Adult↗
PubMed1995

Characteristics of individuals who excrete versus retain sodium under stress.

To examine the role of stress on renal sodium excretion, we studied 27 normotensive and 21 hypertensive subjects. All subjects were placed on a standardized sodium diet. After water loading (2290 ml in 3 1/2 hr) they completed a 30 min baseline and a 30 min stress period (competitive videogame). Sixty-nine percent of the subjects increased ("excreters") and 31% decreased ("retainers") their sodium excretion under stress. In addition to increased potassium excretion (p < 0.006), excreters also manifested less of a stress associated increase in systolic (p = 0.055) and diastolic (p = 0.040) blood pressure and showed greater expression of anger (p < 0.02) than retainers. The same subjects were also studied to determin the effects of angiotensin converting enzyme inhibition (captopril 25 mg b.i.d.) on sodium excretion. On captopril, excreters now showed a retention of sodium (p < 0.001) and potassium (p < 0.01) under stress and no longer differed significantly in blood pressure reactivity. The results suggest that there are two different stress-related patterns of renal sodium excretion, that these patterns are related to blood pressure responses to stress, and may be related to anger expression. In addition, sodium excretion patterns under stress may be altered with certain type of antihypertensive medications.

Adult↗
PubMedDate not supplied

Botulinum toxin type A and EMG: a key to the understanding of chronic tension-type headaches?

BACKGROUND: The pathogenesis of chronic tension-type headache remains unclear, and the role of muscle tension is especially controversial. Botulinum toxin type A, a potent inhibitor of muscle tone, has been used to treat chronic tension-type headache. OBJECTIVE: To determine whether clinical response to treatment of chronic tension-type headache with Botox A parallels changes in resting muscle activity recorded through serial electromyography (EMG). METHODS: We randomly assigned eight patients with chronic tension-type headache to pericranial injection of 500 MU Botox A versus placebo (isotonic saline). RESULTS: At 6 and 12 weeks following treatment, there were no significant differences in clinical outcome between the placebo and the Botox A groups. This occurred despite EMG evidence of a reduction in resting muscle activity in the Botox A-treated patients. CONCLUSION: These results support the hypothesis that peripheral mechanisms such as increased muscle tone play, at most, a minor role in the pathophysiology of chronic tension-type headache.

Adult↗