Patient-Controlled Intravenous Morphine Analgesia Combined with Transcranial Direct Current Stimulation for Post-Thoracotomy Pain: A Cost-Effectiveness Study and A Feasibility For Its Future Implementation.

This prospective randomized study aims to evaluate the feasibility and cost-effectiveness of combining transcranial direct current stimulation (tDCS) with patient controlled intravenous morphine analgesia (PCA-IV) as part of multimodal analgesia after thoracotomy. Patients assigned to the active treatment group (a-tDCS, n = 27) received tDCS over the left primary motor cortex for five days, whereas patients assigned to the control group (sham-tDCS, n = 28) received sham tDCS stimulations. All patients received postoperative PCA-IV morphine. For cost-effectiveness analysis we used data about total amount of PCA-IV morphine and maximum visual analog pain scale with cough (VASP-Cmax). Direct costs of hospitalization were assumed as equal for both groups. Cost-effectiveness analysis was performed with the incremental cost-effectiveness ratio (ICER), expressed as the incremental cost (RSD or US$) per incremental gain in mm of VASP-Cmax reduction. Calculated ICER was 510.87 RSD per VASP-Cmax 1 mm reduction. Conversion on USA market (USA data 1.325 US$ for 1 mg of morphine) revealed ICER of 189.08 US$ or 18960.39 RSD/1 VASP-Cmax 1 mm reduction. Cost-effectiveness expressed through ICER showed significant reduction of PCA-IV morphine costs in the tDCS group. Further investigation of tDCS benefits with regards to reduction of postoperative pain treatment costs should also include the long-term benefits of reduced morphine use.

Effects of anodal tDCS and occupational therapy on fine motor skill deficits in patients with chronic stroke.

BACKGROUND: A growing body of evidence supports the effectiveness of using transcranial direct current stimulation (tDCS) in patients with chronic hand motor impairment resulting from stroke. OBJECTIVE: In this study, we investigate and compare the combined effects of anodal tDCS and occupational therapy (OT) to sham stimulation with OT (control) on fine motor skill deficits of chronic stroke patients. METHODS: A total of 26 stroke patients (at ≥ 9 months) were randomly assigned to an active treatment or a control group in a double-blinded, sham-controlled, parallel design study. Each group received OT for 45 min/day (10 sessions for 2 weeks). Treatment was preceded by either 20 minutes of 2 mA anodal tDCS over ipsilesional M1 or sham tDCS. A modified Jebsen-Taylor Hand Function Test (mJTHFT) was administered as primary outcome measure, and handgrip dynamometer and upper limb Fugl-Meyer (ULFM) assessments were performed as secondary outcomes. The assessment was done at baseline (T0), after the interventions on day 1(T1), day 10 (T2) and day 40 (T3). RESULTS: We observed a statistically significant effect in the tDCS group when the results were compared to the sham group. The mJTHFT times were significantly shorter immediately after treatment and at day 40. The intervention had no effect on handgrip strength or ULFM score. CONCLUSION: Fine motor skill deficits in chronic stroke survivors can be improved when intensive OT is primed with anodal tDCS over the ipsilesional hemisphere.

Low-frequency repetitive transcranial magnetic stimulation in the right prefrontal cortex combined with partial sleep deprivation in treatment-resistant depression: a randomized sham-controlled trial.

INTRODUCTION: Sham-controlled low-frequency repetitive transcranial magnetic stimulation (rTMS) was used in patients with pharmacoresistant major depression as an added treatment along with partial sleep deprivation (PSD). In addition, the potential predictive role of brain-derived neurotrophic factor genetic polymorphism on treatment response was analyzed. METHODS: We recruited 19 female patients (48.3 ± 8.6 years old) with treatment-resistant unipolar major depression (Hamilton Depression Rating Scale [HDRS] score ≥20) who were on a stable antidepressant treatment. They received either 1-Hz rTMS or sham stimulation over the right dorsolateral prefrontal cortex (intensity of 110% of the threshold; 3000 stimuli per protocol; and 10 daily sessions). Additionally, PSD was applied once per week during the treatment. The patients were evaluated (HDRS and Clinical Global Impression Scale) by a blind rater at baseline (B) and after 2 and 3 weeks (W2 and W3) of treatment for short-term outcome. Long-term evaluations were performed after 12 (W12) and 24 weeks (W24) for patients who received active stimulation. RESULTS: Eleven patients in the active group showed a significant HDRS score reduction from 30.09 ± 3.53 (B) to 16.73 ± 5.71 (W3) compared to the lack of therapeutic response in the sham-treated patients. The long-term follow-up for the active group included 64% of the responders at W12 and 55% at W24. Full remission (HDRS ≤10) was achieved in 5 of 11 patients. Four of these 5 patients with long-term sustained remission expressed the Val66Val genotype. CONCLUSION: Our study suggests a clinically relevant response, persisting for up to 6 months, from 1-Hz rTMS over the right dorsolateral prefrontal cortex and PSD in patients with pharmacoresistant major depression. The brain-derived neurotrophic factor Val66Val homozygous genotype may be related to a better treatment outcome.

Oxime and atropine failure to prevent intermediate syndrome development in acute organophosphate poisoning.

INTRODUCTION: Intermediate syndrome (IMS) was described a few decades ago, however, there is still a controversy regard ing its exact etiology, risk factors, diagnostic parameters and required therapy. Considering that acute poisonings are treated in different types of medical institutions this serious complication of organophosphate insecticide (OPI) poison ing is frequently overlooked. The aim of this paper was to present a case of IMS in organophosphate poisoning, which, we believe, provides additional data on the use of oxime or atropine. CASE REPORT: After a well-resolved cholinergic crisis, the patient developed clinical presentation of IMS within the first 72 h from deliberate malathion ingestion. The signs of IMS were weakness of proximal limb muscles and muscles innervated by motor cranial nerves, followed by the weakness of respiratory muscles and serious respiratory insufficiency. Malathion and its active metabolite were confirmed by ana lytical procedure (liquid chromatography-mass spectrometry). Pralidoxime methylsulphate, adiministered as a continuous in fusion until day 8 (total dose 38.4 g), and atropine until the day 10 (total dose 922 mg) did not prevent the development of IMS, hence the mechanical ventilation that was stopped after 27 h had to be continued until the day 10. CONCLUSION: Continuous pralidoxime methylsulphate infusion with atro pine did not prevent the development of IMS, most likely due to the delayed treatment and insufficient oxime dose but also because of chemical structure and lipophilicity of ingested OPI. A prolonged intensive care monitoring and respiratory care are the key management for the intermediate syndrome.

Changes in motor cortex excitability associated with muscle fatigue in patients with Parkinson's disease.

BACKGROUND/AIM: Transcranial magnetic stimulation (TMS) is a standard technique for noninvasive assessment of changes in central nervous system excitability. The aim of this study was to examine changes in responses to TMS in patients suffering from Parkinson's disease (PD) during sustained submaximal isometric voluntary contraction [60% of maximal voluntary contraction (MVC)] of the adductor pollicis muscle, as well as during a subsequent recovery period. METHODS: Cortical excitability was tested by single TMS pulses of twice of the motor threshold intensity applied over the vertex. Testing was carried out during the sustained contraction phase every 10 s before and every 5 s after the endurance point, as well as at rest and during brief 60% MVC contractions before (control), immediately after the sustained contraction, and at 5 min intervals during the recovery period. RESULTS: Although the PD patients could sustain the contraction at the required level for as long period of time as the healthy subjects (though contraction level subsided more rapidly after the endurance point), effects of muscle fatigue on the responses to TMS were different. In contrast to the findings observed in the healthy people where motor evoked potentials (MEP) and EMG silent period (SP) in fatigued muscle gradually diminished during contraction up to the endurance point, and increased thereafter, in the majority of patients no changes occurred in MEP size (peak and area) of the adductor pollicis muscle, either before or after the endurance point. On the other hand, changes in the SP of this muscle differed among the subjects, showing a gradual increase, a decrease or no changes in duration. The trends of changes in both MEP size and SP duration in the musculus brachioradialis varied among the tested PD patients, without any consistent pattern, which was in contrast with the findings in the healthy people where both measures showed a gradual increase from the beginning of the sustained contraction. A complete dissociation between changes in MEP and SP during fatigue was also of note, which differed sharply from the findings in the healthy people in who fatigue induced changes in these measures followed identical patterns. CONCLUSION: These results in the PD patients suggest the presence of impairment and/or compensatory changes in mechanisms responsible for adaptation of voluntary drive as well as for matching between cortical excitation and inhibition which become manifest in demanding motor tasks such as those imposed by muscle fatigue.

[Effects of diazepam and levodopa single doses on motor cortex plasticity modulation in healthy human subjects: a TMS study].

INTRODUCTION: Administration of pharmacological agents with specific actions on neurotransmitter systems is a powerful driver of functional cortical reorganization. Plastic reorganization of the motor cortex in humans studies by the use of non-invasive stimulation protocols, which mimic the Hebbian model of associative plasticity. OBJECTIVE: Aiming to explore pharmacological modulation on human motor cortex plasticity, we tested healthy subjects after each dosage of diazepam, levodopa i placebo administration, using paired associative stimulation protocol (PAS) that induce fenomena similar to a long-term potentiation and depression, as defined on the synaptic level. METHODS: We analyzed effects of benzodiazepines (10 mg), levodopa (200 mg) and placebo on PAS protocol in 14 healthy volunteers, using a double-blind placebo-controlled study design. PAS consisted of electrical stimuli pairs at n.medianus and magnetic pulses over the scalp (transcranial magnetic stimulation) in precisely defined intervals (ISI was 10 and 25 ms) for a total of about 15 minutes (200 pairs). MEP amplitudes before and after (0, 10, 20 and 30 minutes later) interventional protocols were compared. RESULTS: When protocols were applied with placebo depending on ISI (10 ms--inhibitory, 25 ms--facilitatory effects), MEP amplitudes decreased or increased, while values in the post-interventional period (0, 10, 20 and 30 min) were compared with initial values before the use of SAS. The use of benzodiazepines caused the occlusion of LTP-like effect, in contrast to amplification effects recorded after the administration of levodopa. With respect to the LTD-like protocol, the reverse was true (ANOVA for repeat measurements p < 0.001). CONCLUSION: Administration of GABA-ergic agonist diazepam interferes with the induction of associative plasticity in the motor cortex of healthy individuals, as opposed to the use of levodopa, which stimulates these processes. The observed effects point at a potential role of pharmacological modulation of plasticity in humans.

[Neurophysiological evaluation of patients with degenerative diseases of the cervical spine].

BACKGROUND/AIM: Diagnostic protocol for patients with degenerative diseases of the cervical spine demands, in parallel with neuroimaging methods, functional evaluation through neurophysiological methods (somatosensitive and motor evoked potentials and electromyoneurography) aiming to evaluate possible subclinical affection of spinal medula resulting in neurological signs of long tract abnormalities. Considering diversities of clinical outcomes for these patients, complex diagnostic evaluation provides a prognosis of the disease progression. METHODS. The study included 21 patients (48.24 +/- 11.01 years of age) with clinical presentation of cervical spondylarthropathy, without neuroradiological signs of myelopathy. For each patient, in addition to conventional neurophysiological tests (somatisensory evoked potentials--SSEP, motor evoked potentials--MEP, electromyoneurography--EMG, nerve conduction studies), we calculated central motor conduction time (CMCT(F)), as well the same parameter in relation to a different position of the head (maximal anteflexion and retroflexion), so-called dynamic tests. RESULTS: Abnormalities of the peripheral motor neurone by conventional EMNeG was established in 2/3 of the patients, correponding to the findings of root condution time. Prolonged conventional CVMP(F) were found in 29% of the patients, comparing to 43% CVMP(F) abnormalities found with the dynamic tests. In addition, the SSEP findings were abnormal in 38% of the patients with degenerative diseases of the cervical spine. CONCLUSION: An extended neurophysiological protocol of testing corticospinal functions, including dynamic tests of central and periheral motor neurons are relevant for detection of subclinical forms of cervical spondylothic myelopathy, even at early stages. In addition to the conventional neurophysiological tests, we found useful to include the dynamic motor tests and root conduction time measurement in diagnostic evaluation.

The efficacy of two protocols for inducing motor cortex plasticity in healthy humans--TMS study.

Stimulation-induced plasticity represents an experimental model of motor cortex reorganization. It can be produced in awaked humans by combining the non-invasive electrical stimulation of somatosensory afferents via mixed peripheral nerves with the transcranial magnetic stimulation (TMS) of the motor cortex. Animal experiments indicate that an application of two converging inputs from various sources in a tightly coupled manner, following the so called Hebbian rule of learning, leads to an increase in motor cortical excitability. The aim of our study was to compare the effects of two plasticity-inducing protocols by quantifying the motor cortex changes using TMS. Plasticity was induced by combining peripheral nerve stimulation with TMS (paired associative stimulation - PAS) and by peripheral motor point stimulation of two adjacent hand muscles (dual associative stimulation - DAS). The protocols were randomly applied in 12 right-handed healthy volunteers. The amplitudes of TMS-induced motor-evoked potentials (MEPs) in the right abductor pollicis brevis muscle were recorded before, immediately after PAS or DAS stimulation, and 10, 20 and 30 min later. Both protocols led to significant and lasting changes in MEP amplitudes, however, a significantly larger increase in MEPs was observed after PAS than DAS. The results indicate that afferent input can differently affect cortical motor circuits and produce variable motor output. Thus, the efficacy of LTP-like mechanisms, presumably involved in Hebbian-like plasticity in humans, varies with the types/origin of the converging inputs. Our findings may be relevant when designing therapeutic interventions for improving motor function after neurological injury or disease.