Effect of transcranial direct current brain stimulation of the motor cortex on chemotherapy induced nausea and vomiting in female patients with breast cancer

OBJECTIVE

Chemotherapy-induced nausea and vomiting (CINV) is a negative impact associated to chemotherapy and its management still challenging. This study aimed to research the additive impact of single-session tDCS (2 mA) over the motor cortex for 20 minutes before chemotherapy to antiemetic on CINV in female patients suffers from breast cancer who obtained highly emetogenic chemotherapy.

STUDY LAYOUT

Prospective randomized double-blind Sham-controlled study.

SETTING

Academic medical center.

METHOD

Sixty breast cancer patients prepared for chemotherapy treatment were selected and allocated randomly into two equal groups: a real and a sham group; tDCS became implemented over the primary motor area (M1) (2 mA) for 20 minutes. Patients' nausea was measured by cumulative index of nausea and visual analog scale for nausea (VAS-N), and vomiting by cumulative index of episodes of vomiting, and Edmonton symptoms Assessment Scale (ESAS) to assess symptoms like pain, malaise, and sense of well-being. Evaluation was done prestimulation and every 24 h for 72 h after end of infusion of chemotherapy.

RESULTS

Real tDCS group showed reduction of cumulative index of nausea (P < 0.001, F = 50), VAS-N (P < 0.001, F = 52) and for ESAS in malaise score (P < 0.001, F = 37.6) and sense of wellbeing score (P < 0.001, F = 25) than sham group. Six patients (20%) in the real group required rescue antiemtic therapy vs. 14 patients (46.7%) in the Sham group (P < 0.028).

CONCLUSION

Single session of real M1 tDCS could be suggested as an effective adjuvant maneuver in control of CINV in female patients suffers from breast cancer who obtained highly emetogenic chemotherapy.

TRIAL REGISTRATION

Clinical Trials.gov trial registry (identifier: NCT03405324).

Preemptive Stem Cells Ameliorate Neuropathic Pain in Rats: A Central Component of Preemptive Analgesia

The present study aims to investigate the efficacy of intravenously injected mesenchymal stem cells (MSCs) in treating neuropathic pain either before or after its induction by a chronic constriction injury (CCI) model. Rats were divided into four groups: control group, neuropathic group, and treated groups (pre and postinduction) with i.v. mononuclear cells (106 cell/mL). For these rats, experimental testing for both thermal and mechanical hyperalgesia was evaluated. The cerebral cortex of the rats was dissected, and immunohistochemical analysis using anti-proliferating cell nuclear antigen (PCNA), CD117, nestin, and glial fibrillary acidic protein was performed. Our results showed that a single injection of MSCs (either preemptive/or post-CCI) produced equipotent effects on allodynia, mechanical hyperalgesia, and thermal response. Immunohistochemical analysis showed that the stem cells have reached the cerebral cortex. The injected group with MSCs before CCI showing few stem cells expressed PCNA, CD117, and nestin in the cerebral cortex. The group injected with MSCs after CCI, showing numerous recently proliferated CD117-, nestin-, PCNA-positive stem cells in the cerebral cortex. In conclusion, our findings demonstrate that the most probable effect of i.v. stem cells is the central anti-inflammatory effect, which opens concerns about how stem cells circulating in systemic administration to reach the site of injury.

Repetitive transcranial magnetic stimulation in neuropathic pain secondary to malignancy: a randomized clinical trial

BACKGROUND

Significant analgesic effects of repetitive transcranial magnetic stimulation (rTMS) have been found in several studies of patients with chronic pain of various origins, but never for malignancy. The objective of this study was to assess the efficacy of 10 sessions of rTMS over the primary motor cortex (M1) in patients suffering from malignant neuropathic pain.

METHODS

Thirty-four patients were randomly allocated into one of two groups to receive real (20 Hz, 10 s, 10 trains with 80% intensity) or sham rTMS daily for 10 consecutive days. Patients were evaluated using a verbal descriptor scale (VDS), a visual analogue scale (VAS), Leeds assessment of neuropathic symptoms and signs (LANSS) and Hamilton rating scale for depression (HAM-D) at baseline, after the first, fifth and 10th treatment sessions, and then 15 days and 1 month after treatment.

RESULTS

There were no significant differences between real and sham groups in the duration of illness or pain rating scores at the baseline. A significant 'Time × Group' interaction was recorded indicating that real and sham rTMS had different effects on the VDS, VAS, LANSS and HAM-D scales. Post-hoc testing showed that the group of patients treated with real rTMS had greater improvement in all scales that persisted up to 15 days, but were not present 1 month later. Significant positive correlations between the percentage of pain reduction and HAM-D after the 10th session and 15 days later were recorded.

CONCLUSION

The results demonstrate that 10 rTMS sessions over the M1 can induce short-term pain relief in malignant neuropathic pain.

The effects of dexmedetomidine alone and in combination with tramadol or amitriptyline in a neuropathic pain model

BACKGROUND

Interactions between the sympathetic and somatic nervous system play an essential role in the pathophysiologic mechanisms of neuropathic pain. The α2-adrenoceptor agonists produce effective antinociception, but sedation is an important adverse effect. Multidrug therapy is potentially valuable to decrease side effects.

OBJECTIVE

The aim of the present study was to investigate the possible antinociceptive effect of dexmedetomidine, an α2-adrenoceptor agonist, and its combination with front-line treatment of neuropathic pain, i.e., amitriptyline or tramadol, in a chronic constriction injury (CCI) model of the sciatic nerve in rats.

STUDY DESIGN

Controlled animal study.

METHODS

Following unilateral ligation of the left sciatic nerve, the effect of intraperitoneal (i.p.) dexmedetomidine (5 ug/kg), tramadol (5 mg/kg), and amitriptyline (30 mg/kg) on mechanical allodynia (measured by electrical von Frey apparatus) and hyperalgesia (measured by Randall and Selitto test) was studied.

RESULTS

The sham-operated rats and un-operated hind paw (right paw) press normally on the floor reproduced by a weighted pain score of 0. Behavioral and mechanical tests confirmed the development of neuropathic pain after CCI. All individual drugs and dexmedetomidine combination with either tramadol or amitriptyline were effective in reducing mechanical allodynia and hyperalgesia. Dexmedetomidine, amitriptyline, tramadol, amitriptyline+dexmedetomidine, and tramadol+dexmedetomidine combination did not produce any sedation/motor impairment (P > 0.05).

LIMITATIONS

Although the combination of these drugs improved the CCI model of neuropathic pain in this study, an additional interpretation of the underlying mechanism(s) will be needed to confirm these findings.

CONCLUSION

The combination of these drugs appears to be more effective in increasing the pain threshold after peripheral nerve injury, when compared with the administration of either of amitriptyline or tramadol alone and should be considered as a possible alternative to decrease side effects of individual drug therapy.

Pharmacokinetics of controlled release morphine (MST) in patients with liver cirrhosis

We have studied the kinetic profile of controlled release morphine (MST) in 12 patients with posthepatitic cirrhosis, caused by HCV and HBsAg, with portal hypertension, given MST 30 mg for endoscopic sclerotherapy and compared the data with those from 10 healthy controls. Plasma drug concentrations were measured in venous blood samples at intervals up to 12 h by high-pressure liquid chromatography (HPLC). Total body clearance (Cl) and systemic availability were estimated using a compartmental method. Patients with cirrhosis had less clearance (0.586 litre h-1) than controls (0.729 litre h-1). Mean residence time (MRT) was prolonged in cirrhotic patients (19.57 h) compared with controls (7.03 h). Elimination half-life in cirrhotic patients (mean 7.36 (SEM 0.45) h) was nearly twice that of controls (4.01 (0.15) h). Serum concentrations were higher at all sampling times in the cirrhotic patients (peak concentration 35.2 (3.2) ng ml-1 compared with 12.8 (0.4) ng ml-1 in controls). For these changes in the kinetic profile of morphine (as MST) in cirrhotic patients, who experienced more sedation than controls, a smaller dose study together with longer dosing intervals is recommended.

Epidural abscess after spinal anesthesia: a favorable outcome

A case of lumbar epidural abscess after spinal anesthesia with sciatica and sphincteric disturbance is presented. The case was investigated by myelography and diagnosed after exploration, resulting in dramatic improvement.