Jens D. Rollnik

The effect of ethnicity on prescriptions for patient-controlled analgesia for post-operative pain

&NA; We studied if ethnicity influences patient‐controlled analgesia (PCA) for the treatment of post‐operative pain. Using a retrospective record review, we examined data from all patients treated with PCA for post‐operative pain from January to June 1993. We excluded patients who did not have surgery prior to the prescription of PCA or were not prescribed PCA in the immediate post‐operative period. The sample consisted of 454 subjects. While there were no differences in the amount of narcotic self‐administered, there were significant differences in the amount of narcotic prescribed among Asians, Blacks, Hispanics, and Whites (F = 7.352, P < 0.01). The ethnic differences in prescribed analgesic persisted after controlling for age, gender, pre‐operative use of narcotics, pain site, and insurance status. Patients ethnicity has a greater impact on the amount of narcotic prescribed by the physician than on the amount of narcotic self‐administered by the patient.

Repetitive Transcranial Magnetic Stimulation for the Treatment of Chronic Pain – A Pilot Study

Invasive electrical stimulation of the motor cortex has been reported to be of therapeutic value in pain control. We were interested whether noninvasive repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex might also act beneficially. Twelve patients with therapy-resistant chronic pain syndromes (mean age 51.3 ± 12.6, 6 males) were included in a pilot study. They were treated with rTMS of the corresponding motor cortex area for 20 min (20 Hz, 20 × 2 s trains, intensity 80% of motor threshold) and sham stimulation (sequence-controlled cross-over design). Some of the patients (6/6) had an analgesic effect, but for the whole group, the difference between active and sham stimulation did not reach a level of significance (active rTMS: mean VAS reduction –4.0 ± 15.6%; sham rTMS: –2.3 ± 8.8%). Further studies using different rTMS stimulation parameters (duration and frequency of rTMS) or stimulation sites (e.g. anterior cingulate gyrus) are strongly encouraged.

Pressure pain threshold and needle acupuncture in chronic tension-type headache – a double-blind placebo-controlled study

&NA; In order to examine the role of muscular mechanisms in chronic tension‐type headache a study with needle acupuncture was performed. Needle acupuncture could be of therapeutic value because it has shown some positive effects in myofascial pain syndromes. We performed a double‐blind, placebo‐controlled study with 39 patients (mean age 49.0 years, SD=14.8) fulfilling the International Headache Society criteria for chronic tension‐type headaches. Participants were randomly assigned to verum or placebo condition. Six weeks after end of treatment no significant differences between placebo and verum could be observed with respect to visual analogue scale and frequency of headache attacks. Nevertheless, pressure pain thresholds significantly increased for the verum group. The findings of our study support the hypothesis that peripheral mechanisms – such as increased muscle tenderness – only play a minor role in the pathogenesis of chronic tension‐type headache.

Increased intracortical inhibition in middle-aged humans; a study using paired-pulse transcranial magnetic stimulation

Using single and paired-pulse transcranial magnetic stimulation we compared the cortical excitability in two different age groups of healthy subjects (mean+/-SD age: 28.5+/-5.2 vs. 56.1+/-4.9 years). Motor evoked potentials were recorded from right extensor and flexor carpi radialis muscles. The effect of paired-pulse stimulation was assessed by the ratio conditioned/unconditioned response area with interstimulus intervals of 3 and 13 ms to test for intracortical inhibition and facilitation, respectively. To test the influence of sensory input the experiments were conducted without and with vibration of the extensor carpi radialis muscle. The intracortical inhibition was significantly greater in older subjects; however, during muscle vibration this difference between the two groups vanished. The different effect of vibration favors compensatory mechanisms to be responsible for a different paired-pulse excitability in middle-aged subjects.

Triple stimulation technique (TST) in amyotrophic lateral sclerosis

OBJECTIVE The authors studied amyotrophic lateral sclerosis (ALS) patients using triple stimulation technique (TST) to detect upper motor neuron (UMN) involvement. METHODS Nineteen ALS patients (aged 45-72 years) were enrolled in the study. According to the El Escorial criteria, 6 diagnoses were suspected or possible, 6 probable, and 7 definite. Patients were examined clinically, with conventional (single-pulse) transcranial magnetic stimulation (TMS), and with TST (on one side only). RESULTS Among the whole group of patients, TST appeared to be more sensitive than conventional TMS techniques. In particular among suspected/possible ALS patients, TST area ratio was pathologic in 100%, while single-pulse TMS was abnormal only in 50% of cases. Overall, the use of TST area ratio was more sensitive than the analysis of TST amplitude ratio. CONCLUSIONS The results suggest that TST might be more sensitive and useful in the diagnosis of subclinical UMN involvement than conventional TMS techniques, even if TST is performed on one side only.

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.

Gender differences in the effect of repetitive transcranial magnetic stimulation in schizophrenia

Repetitive transcranial magnetic stimulation (rTMS) can be beneficial in schizophrenia, possibly through a reversal of pre-treatment hypofrontality. Twelve schizophrenic patients (8 men, 4 women) were treated with high-frequency rTMS of the dominant dorsolateral prefrontal cortex. Their performance of the number-connection test, which assesses cognitive processes related to the frontal lobe, was evaluated before and after rTMS. Women improved markedly on the test after rTMS, whereas men did not show a significant change. There were no corresponding sex differences in clinical measures after rTMS. The preliminary findings of sex differences in the response to rTMS, as reflected by performance on the number-connection test, suggest the need for investigations of a greater number of schizophrenic men and women with a more intensive examination of the effects of rTMS on cognitive functions.

Coping Strategies in Episodic and Chronic Tension-type Headache

Objective.—To study the importance of coping with illness strategies in tension‐type headache (TTH).

Impaired sensorimotor integration in cervical dystonia: a study using transcranial magnetic stimulation and muscle vibration.

Summary The authors studied the effects of sensorimotor integration (corticocortical inhibition and facilitation during muscle vibration [MV]) in dystonic patients. Eleven patients with cervical dystonia and 11 age-matched healthy control subjects were enrolled in the study. They were examined using transcranial magnetic stimulation (TMS) and tonic proprioceptive input (MV). Paired-pulse transcranial magnetic stimulation was done at interstimulus intervals of 3 msec (intracortical inhibition) and 13 msec, the intensity of the conditioning stimulus was 70% of the motor threshold, and the test stimulus was 120%. Motor evoked potentials were recorded from the vibrated extensor carpi radialis muscle and its antagonist, the flexor carpi radialis. Duration of MV trains (80 Hz; amplitude, 0.5 mm) was 4 seconds. The authors found differences between patients and healthy control subjects during MV only. Intracortical inhibition was pronounced significantly only in control subjects, whereas intracortical facilitation was significant in patients only (P < 0.05). Furthermore, the significant reduction of motor evoked potentials at 13-msec interstimulus intervals, which can be found in healthy subjects frequently, was observed in one dystonia patient only. The results of the current study suggest that sensorimotor integration is impaired in cervical dystonia, probably by an altered control of proprioceptive (vibratory) input.

Short-term cognitive improvement in schizophrenics treated with typical and atypical neuroleptics.

Objective: Atypical neuroleptics seem to be more beneficial than typical ones with respect to long-term neuropsychological functioning. Thus, most studies focus on the long-term effects of neuroleptics. We were interested in whether atypical neuroleptic treatment is also superior to typical drugs over relatively short periods of time. Methods: We studied 20 schizophrenic patients [10 males, mean age 35.5 years, mean Brief Psychiatric Rating Scale (BPRS) score at entry 58.9] admitted to our hospital with acute psychotic exacerbation. Nine of them were treated with typical and 11 with atypical neuroleptics. In addition, 14 healthy drug-free subjects (6 males, mean age 31.2 years) were enrolled in the study and compared to the patients. As neuropsychological tools, a divided attention test, the Vienna reaction time test, the Benton visual retention test, digit span and a Multiple Choice Word Fluency Test (MWT-B) were used during the first week after admission, within the third week and before discharge (approximately 3 months). Results: Patients scored significantly worse than healthy controls on nearly all tests (except Vienna reaction time). Clinical ratings [BPRS and Positive and Negative Symptom Scale for Schizophrenia (PANSS)] improved markedly (p < 0.01), without a significant difference between typical and atypical medication. Clinical improvement (PANSS total score) correlated with less mistakes on the Benton test (r = 0.762, p = 0.017) and an improvement on the divided attention task (r = 0.705, p = 0.034). Neuropsychological functioning (explicit memory, p < 0.01; divided attention, p < 0.05) moderately improved for both groups under treatment but without a significant difference between atypical and typical antipsychotic drugs. Conclusions: Over short periods of time (3 months), neuropsychological disturbances in schizophrenia seem to be moderately responsive to both typical and atypical neuroleptics.