Cryoneurolysis in Patients with Dorsal Neuropathic Pain Secondary to Tumor Invasion.

PURPOSE: To evaluate the safety and efficacy of cryoneurolysis (CNL) in patients with refractory thoracic neuropathic pain related to tumor invasion. MATERIALS AND METHODS: Between January 2013 and May 2017, this single-center and retrospective study reviewed 27 computed tomography-guided CNLs performed on 26 patients for refractory thoracic neuropathic pain related to tumor invasion. Patients with cognitive impairment were excluded. Pain levels were recorded on a visual analog scale (VAS) before the procedure, on days 1, 7, 14, 28 and at each subsequent follow-up appointment. CNL was clinically successful if the postprocedural VAS decreased by 3 points or more. To determine the duration of clinical success, the end of pain relief was defined as either an increased VAS of 2 or more points, the introduction of a new analgesic treatment, a death with controlled pain, or for lost to follow-up patients, the latest follow-up appointment date with controlled pain. RESULTS: Technical success rate was 96.7% and clinical success rate was 100%. Mean preprocedural pain score was 6.4 ± 1.7 and decreased to 2.4 ± 2.4 at day 1; 1.8 ± 1.7 at day 7 (P < .001); 3.3 ± 2.5 at day 14; 3.4 ± 2.6 at day 28 (P < .05). The median duration of pain relief was 45 days (range 14-70). Two minor complications occurred. CONCLUSIONS: Cryoneurolysis is a safe procedure that significantly decreased pain scores in patients with thoracic neuropathic pain related to tumor invasion, with a median duration of clinical success of 45 days.

Unilateral winged scapula: Clinical and electrodiagnostic experience with 128 cases, with special attention to long thoracic nerve palsy.

INTRODUCTION: In this study we report a large series of patients with unilateral winged scapula (WS), with special attention to long thoracic nerve (LTN) palsy. METHODS: Clinical and electrodiagnostic data were collected from 128 patients over a 25-year period. RESULTS: Causes of unilateral WS were LTN palsy (n = 70), spinal accessory nerve (SAN) palsy (n = 39), both LTN and SAN palsy (n = 5), facioscapulohumeral dystrophy (FSH) (n = 5), orthopedic causes (n = 11), voluntary WS (n = 6), and no definite cause (n = 2). LTN palsy was related to neuralgic amyotrophy (NA) in 61 patients and involved the right side in 62 patients. DISCUSSION: Clinical data allow for identifying 2 main clinical patterns for LTN and SAN palsy. Electrodiagnostic examination should consider bilateral nerve conduction studies of the LTN and SAN, and needle electromyography of their target muscles. LTN palsy is the most frequent cause of unilateral WS and is usually related to NA. Voluntary WS and FSH must be considered in young patients. Muscle Nerve 57: 913-920, 2018.

Isolated Peripheral Nerve Palsies in Thoracic Outlet Syndrome.

Thoracic outlet syndrome (TOS) poses a difficult diagnostic entity with varied etiology and clinical presentation. We present a 35-year-old gentleman with unilateral long thoracic nerve palsy and contralateral subscapular paralysis caused by aberrant scalenus medius anatomy. TOS ought to be considered in patients presenting with isolated nerve palsies.

Plantar Sweating as an Indicator of Lower Risk of Compensatory Sweating after Thoracic Sympathectomy.

Background Hyperhidrosis is a dysfunction of the autonomic nervous system that results in regional excessive sweating, mostly in the hands, armpits, and feet. A permanent and effective treatment of hyperhidrosis can be achieved by interruption of the thoracic sympathetic chain with endoscopic thoracic sympathectomy (ETS). However, some side effects, particularly compensatory sweating (CS), are the limitations of this procedure. The mechanism of CS and the associated risk factors are still controversial. The aim of this retrospective study was to determine the relationship with various parameters associated with CS in patients undergoing ETS. Materials and Methods ETS was performed on a total of 95 patients for palmar hyperhidrosis, axillary hyperhidrosis and facial blushing by the same surgeon. The mean age of the patients was 26.41 (± 7) years, and 54 (56.8%) were males. Palmar hyperhidrosis was present in 54 (56.8%) patients, axillary hyperhidrosis in 33 (34.7%) patients, and facial blushing in 8 (8.5%) patients. Moreover, 38 (40%) patients also had plantar sweating. The severity of CS was rated into three scales as less, moderate, and severe. Results Regarding the severity of CS, 55 (57.9%) patients had no or less CS, 28 (29.5%) had moderate CS, and 12 (12.6%) patients had severe CS. Higher age group had a significant increased risk of severe CS (p = 0.03) (r = 0.262). Patients with body mass index (BMI) > 25 kg/m2 had a statistically significantly increased risk of severe CS (p = 0.016). Facial blushing resulted in severe CS in a significantly higher proportion of patients than by palmar and axillary hyperhidrosis (p = 0.001). The level of surgery was another important risk factor for CS, with the T2 level showing an increased risk of severe CS compared with T3 level (p < 0.001). Furthermore, plantar sweating was inversely and significantly related to the development of CS. Patients with plantar sweating had a significantly decreased incidence of developing CS (p = 0.015). Conclusion CS after thoracic sympathectomy for primary hyperhidrosis is the most displeasing and restrictive side effect. This study demonstrates that older age, operation level, facial blushing, and high BMI are risk factors for CS, as have been shown in several similar studies. An interesting finding of the present study is that there was a decreased incidence of CS among patients with plantar sweating. This situation may help us to distinguish high risk for CS before ETS operation.

Influence of Body Mass Index on Compensatory Sweating in Patients after Thoracic Sympathectomy due to Palmar Hyperhidrosis.

Background Thoracic sympathectomy (TS) is one of the most effective methods of treatment of primary hyperhidrosis. One of the side effects of this procedure is compensatory sweating (CS). Objective The aim of our study was to evaluate the influence of body mass index (BMI) on CS in patients after TS due to palmar hyperhidrosis. Methods Data from 157 patients with palmar hyperhidrosis who underwent TS were collected. The patients were subsequently divided in two groups according to their initial BMI: group A, BMI < 25 kg/m2, and group B, BMI ≥ 25 kg/m2. Objective (gravimetry) and subjective (VAS) measurements of the intensity of hyperhidrosis were taken from the patients' bodies prior to surgery, as well as 3 and 12 months after TS. Results Average palmar hyperhidrosis levels before the surgery did not differ significantly between the two groups (238.65 vs. 190.15; p = 0.053). A statistically significant decrease in palmar hyperhidrosis was noted in both groups, both 3 and 12 months after surgery (238.65 vs. 11.86 vs. 13.5; p < 0.05, and 190.15 vs. 16.67 vs. 11.81; p < 0.05, respectively). The intensity of sweating over the abdomino-lumbar area differed significantly between the groups before the surgery, both in subjective (1.71 vs. 3.61; p < 0.05) and objective (13.57 vs. 35.95; p < 0.05) evaluations. Three months after surgical intervention, an intensification of CS was observed in both the groups; however, no statistically significant differences were observed between the two sets of patients (VAS: 4.58 vs. 5.16; p = 0.38; gravimetry: 33.87 vs. 53.89; p = 0.12). Twelve months after TS, CS was higher in the group with an initial BMI ≥ 25 kg/m2, both in subjective and objective evaluations (3.23 vs. 4.94; p = 0.03 and 18.08 vs. 80.21; p = 0.026, respectively). Conclusion Patients with a BMI ≥ 25 kg/m2 experience more severe CS after TS, both in subjective and objective evaluations.

Indirect transfer of the sternal head of the pectoralis major with autogenous semitendinosus augmentation to treat scapular winging secondary to long thoracic nerve palsy.

BACKGROUND: Scapular winging resulting from long thoracic nerve palsy is uncommon but debilitating, and the choice of surgical treatment is inconsistent. The autogenous semitendinosus tendon plays a key role as an interposed tendon graft, although its use in the indirect transfer of the sternal head of the pectoralis major during the treatment of scapular winging has rarely been reported. MATERIALS AND METHODS: A retrospective review was performed during a 9-year period from the clinical data of 26 cases (28 shoulders) with indirect transfer of the sternal head of the pectoralis major with the interposition of an autogenous semitendinosus tendon graft for dynamic stabilization of the scapula. The range of active movement (forward elevation, abduction, and external rotation), American Shoulder and Elbow Surgeons score, visual analog scale score, and complications were evaluated with a mean of 47 months of clinical follow-up. RESULTS: Patients' active shoulder movements (forward elevation, abduction, and external rotation), American Shoulder and Elbow Surgeons score, and visual analog scale score showed significant improvements (P < .01). One seroma developed and resolved with extraction. Four shoulders had adhesive capsulitis and recovered after physiotherapy. There was no recurrence of scapular winging in any patient. CONCLUSION: Timely treatment, often surgical, is vital to the recovery of scapular winging secondary to long thoracic nerve palsy. Our results suggest that indirect transfer of the sternal head of the pectoralis major with interposition of the autogenous semitendinosus tendon can effectively treat scapular winging due to long thoracic nerve palsy with limited sequelae. Widespread use of this technique is recommended.

Estimating sympathetic tone by recording subcutaneous nerve activity in ambulatory dogs.

INTRODUCTION: We tested the hypothesis that subcutaneous nerve activity (SCNA) of the thorax correlates with the stellate ganglion nerve activity (SGNA) and can be used to estimate the sympathetic tone. METHODS AND RESULTS: We implanted radio transmitters in 11 ambulatory dogs to record left SGNA, left thoracic vagal nerve activity (VNA), and left thoracic SCNA, including 3 with simultaneous video monitoring and nerve recording. Two additional dogs were studied under general anesthesia with apamin injected into the right stellate ganglion while the right SGNA and the right SCNA were recorded. There was a significant positive correlation between integrated SGNA (iSGNA) and integrated SCNA (iSCNA) in the first 7 ambulatory dogs, with correlation coefficient of 0.70 (95% confidence interval [CI] 0.61-0.84, P < 0.05 for each dog). Tachycardia episodes (heart rate exceeding 150 bpm for ≥3 seconds) were invariably preceded by SGNA and SCNA. There was circadian variation of both SCNA and SGNA. Crosstalk was ruled out because SGNA, VNA, and SCNA bursts had different timing and activation patterns. In an eighth dog, closely spaced bipolar subcutaneous electrodes also recorded SCNA, but with reduced signal to noise ratio. Video monitoring in additional 3 dogs showed that movement was not a cause of high frequency SCNA. The right SGNA correlated strongly with right SCNA and heart rate in 2 anesthetized dogs after apamin injection into the right stellate ganglion. CONCLUSIONS: SCNA recorded by bipolar subcutaneous electrodes correlates with the SGNA and can be used to estimate the sympathetic tone.

Maternal protein restriction increases respiratory and sympathetic activities and sensitizes peripheral chemoreflex in male rat offspring.

BACKGROUND: Maternal protein restriction in rats increases the risk of adult offspring arterial hypertension through unknown mechanisms. OBJECTIVES: The aims of the study were to evaluate the effects of a low-protein (LP) diet during pregnancy and lactation on baseline sympathetic and respiratory activities and peripheral chemoreflex sensitivity in the rat offspring. METHODS: Wistar rat dams were fed a control [normal-protein (NP); 17% protein] or an LP (8% protein) diet during pregnancy and lactation, and their male offspring were studied at 30 d of age. Direct measurements of baseline arterial blood pressure (ABP), heart rate (HR), and respiratory frequency (Rf) as well as peripheral chemoreflex activation (potassium cyanide: 0.04%) were recorded in pups while they were awake. In addition, recordings of the phrenic nerve (PN) and thoracic sympathetic nerve (tSN) activities were obtained from the in situ preparations. Hypoxia-inducible factor 1α (HIF-1α) expression was also evaluated in carotid bifurcation through a Western blotting assay. RESULTS: At 30 d of age, unanesthetized LP rats exhibited enhanced resting Rf (P = 0.001) and similar ABP and HR compared with the NP rats. Despite their similar baseline ABP values, LP rats exhibited augmented low-frequency variability (∼91%; P = 0.01). In addition, the unanesthetized LP rats showed enhanced pressor (P = 0.01) and tachypnoeic (P = 0.03) responses to peripheral chemoreflex activation. The LP rats displayed elevated baseline tSN activity (∼86%; P = 0.02) and PN burst frequency (45%; P = 0.01) and amplitude (53%; P = 0.001) as well as augmented sympathetic (P = 0.01) and phrenic (P = 0.04) excitatory responses to peripheral chemoreflex activation compared with the NP group. Furthermore, LP rats showed an increase of ∼100% in HIF-1α protein density in carotid bifurcation compared with NP rats. CONCLUSION: Sympathetic-respiratory overactivity and amplified peripheral chemoreceptor responses, potentially through HIF-1α-dependent mechanisms, precede the onset of hypertension in juvenile rats exposed to protein undernutrition during gestation and lactation.

Can Thoracic Sympathetic Nerve Damage Be Reversed?

BACKGROUND: Function of the thoracic sympathetic chain (TSC) reportedly recovers after surgical clips are removed. Hence, this study was designed to study nerve regeneration after unclipping the TSC. METHODS: The bilateral TSCs of six goats were studied; the goats were separated into three groups (groups I, II, and III) during excision, clipping, and unclipping. During surgery, the TSCs were excised with a scalpel in group I and clipped in groups II and III. In group III, the clips were removed 1 month postoperatively and observed for possible nerve healing for 1 month. All TSCs were examined histologically following en block resection at 1 month postoperatively in groups I and II and at 2 months postoperatively in group III. RESULTS: Inflammation in nerve sections was noted following clip removal. Furthermore, there was significant degeneration and cell infiltration in the nerve fibers of the clipped regions. The Schwann cells around the peripheral nerve endings in the unclipped regions facilitated nerve transmission by reconstitution of myelin. CONCLUSION: Clipping the TSC can cause histologic degeneration; however, histologic nerve regeneration occurs after unclipping.

Early thoracic sympathetic block improves the treatment effect for upper extremity neuropathic pain.

BACKGROUND: The sympathetic nervous system has important roles in mediating many neuropathic pain conditions. A thoracic sympathetic block (TSB) is a useful therapeutic procedure for neuropathic pain in the upper extremities and thorax. However, no studies have examined the factors related to an improved therapeutic effect of TSB. In this study, we evaluated the influence of potential prognostic factors for a better TSB effect and identified clinically important prognostic factors. METHODS: Percutaneous TSB was performed in 51 patients, under fluoroscopic guidance. Data collected for each patient included age, gender, body mass index, diagnosis, pain intensity, and symptom duration. The adjusted odds ratios and 95% confidence intervals for each variable were calculated by logistic regression. RESULTS: TSB was more effective in patients with symptom durations of ≤1 year compared with >1 year (P = 0.006; odds ratio, 8.037; 95% confidence interval, 1.808-35.729). Patient age, gender, body mass index, diagnosis, and intensity of pre-TSB pain were not associated with TSB effectiveness. CONCLUSION: The results showed that an earlier TSB produced a better outcome for patients with chronic pain syndrome. Thus, early TSB should be performed in patients with chronic pain in the upper extremities.

Scapular winging: an update.

Scapular winging is a rare disorder often caused by neuromuscular imbalance in the scapulothoracic stabilizer muscles. Lesions of the long thoracic nerve and spinal accessory nerves are the most common cause. Numerous underlying etiologies have been described. Patients report diffuse neck, shoulder girdle, and upper back pain, which may be debilitating, associated with abduction and overhead activities. Accurate diagnosis and detection depend on appreciation of the scapulothoracic anatomy and a comprehensive physical examination. Although most cases resolve nonsurgically, surgical treatment of scapular winging has been met with success.

[Metal stress-induced arrhythmia and thoracic spinal cord 1-5 nerve remodeling and myocardial electrophysiological remodeling in rats].

OBJECTIVE: The study aimed to investigate the relationship between arrhythmia occurrence and nerve remodeling of thoracic spinal cord 1-5 nerves as well as myocardial electrophysiological remodeling in a metal stress rat model. METHODS: Thirty SD rats (weight 180-250 g) were randomly divided into control group (n = 10), stress group (n = 10) and fluoxetine group (n = 10, 10 mg/kg i.p. for 3 weeks). Stress model (given by unpredicted chronic mild stress) was established according to Cronli's protocol. Following parameters were observed:(1) ECG waveform change and arrhythmias;(2) tissue field action potential duration (FAPD) of thoracic spinal cord 1-5 and cardiac tissue mapped by microelectrode arrays (MEA) technique;(3) myocardial growth-associated protein (GAP-43), tyrosine hydroxylase (TH), choline acetyltransferase (CHAT) distribution observed by immunofluorescence and confocal laser scanning microscope (LSCM). RESULTS: Three weeks later: (1) The body weight, food intake, consumption of sugar water, the horizontal and vertical movement score, cleaning action of rats were significantly decreased, and fecal grains significantly increased, P-wave, P-R interval, QRS-wave and Q-T interval were significantly prolonged and heart rate was significantly reduced in stress group compared with control group (all P < 0.05). Incidence of ventricular premature beat was 80% in stress group and 0% in control group (P < 0.05). The FAPD of thoracic spinal cord 1-5 nerves [(144.25 ± 12.63)ms vs (79.56 ± 8.01)ms] and of cardiac tissue [LA(122.43 ± 19.34)ms vs (92.59 ± 7.61)ms, RA(149.89 ± 14.68)ms vs (105.18 ± 15.94)ms, LV(162.62 ± 7.04)ms vs (110.45 ± 6.92)ms, RV(152.21 ± 30.49)ms vs (131.06 ± 12.04)ms] were significantly prolonged, FAPD dispersion (FAPDd) significantly increased [thoracic spinal cord 1-5(13.3 ± 9.11)ms vs (9.36 ± 7.01)ms] in stress group compared with the control group. Disarrangement of myocardial cells, proliferation of collagen fiber, infiltration of neutrophil and lymphocytes in the cardiac tissue were also observed and distribution of GAP-43, TH and CHAT was significantly increased in stress group. (2) All these changes could be partly reversed by the treatment with fluoxetine. CONCLUSION: Metal stress induced cardiac autonomic nerve and myocardial electrophysiological remodeling and ventricular arrhythmia in rats which could be significantly attenuated by fluoxetine in this model.

Ultrasound-Guided Thoracic Paravertebral Nerve Block on Postoperative Pain, Quality of Life, and Recovery in Patients with Non-Small-Cell Lung Cancer.

OBJECTIVES: Our study will investigate the effect of ultrasound-guided thoracic paravertebral block (UG-TPVB) on postoperative pain, quality of life, and enhanced recovery in patients with non-small-cell lung cancer (NSCLC) undergoing lobectomy surgery. METHODS: Our study included 100 patients aged 52 to 75 years who underwent lobectomy surgery with pathological diagnosis of NSCLC. Patients received ultrasound-guided thoracic paravertebral block or general anesthesia with tracheal intubation. Patients' pain score was recorded on a numeric rating scale (NRS) 24 hours post operation. The total postoperative dosage of tramadol hydrochloride, length of hospitalization, quality of life (QoL), and inflammation levels were recorded. RESULTS: Compared with patients who received general anesthesia with tracheal intubation, patients in the UG-TPVB group had lower postoperative NRS scores at 24 h (1.8 vs. 3.5, P = 0.035); the average 24 h postoperative NRS score of the UG-TPVB group is lower than that of the general anesthesia with tracheal intubation (4.6 vs. 5.3, P = 0.012), thus receiving less dosage of tramadol hydrochloride (221 ± 45 vs. 250 ± 38 mg, P < 0.01). Patients in the UG-TPVB group had better EORTC QLQ-C30 scores compared with patients in the general anesthesia with tracheal intubation group. The difference of length of hospitalization, hs-CRP, and IL-6 between two groups did not reach statistical difference (length of hospitalization 6.2 vs. 6.9 days, P = 0.055; hs-CRP: 7.1 ± 1.9 vs. 10.4 ± 6.6, P = 0.095; and IL-6: 71.3 ± 7.2 vs. 68.9 ± 8.7, P = 0.529). Discussion. NSCLC patients undergoing lobectomy surgery who received UG-TPVB had less postoperative pain, used less dosage of tramadol hydrochloride, and had better QoL.

Ultrasound-guided Interfascial Plane Blocks for Non-anesthesiologists in Breast Cancer Surgery: Functional Outcomes and Benefits.

AIM: Acute post-operative pain following modified radical mastectomy (MRM) in patients with breast cancer is challenging for anesthesiologists. This study aimed to prospectively compare the quality outcome of interfascial plane blocks performed with ultrasound guidance, and evaluate the consequences of sharing tasks with the breast surgeon. PATIENTS AND METHODS: The study involved 255 patients scheduled for unilateral MRM, who were divided into two groups: Pecs group: General anesthesia plus ultrasound-guided modified pectoral nerves blocks type I and II, including serratus and parasternal infiltration according to surgical requirements; and Control group: general anesthesia only. Quality was evaluated based on perioperative opioid consumption, reported pain intensity, rescue analgesic requirement, side-effects and length of hospital stay. Moreover, a breast surgeon with expertise in ultrasound-guided breast biopsy was trained to perform the blocks. The patient benefits from regional anesthesia delivered by a non-anesthesiologist were assessed. RESULTS: Significant reductions were noted in all of the following: Intraoperative opioid consumption (p<0.001), Numerating Rating Scale pain scores taken 0 and 24 h after surgery (p<0.001), post-operative analgesic administration (p<0.001), nausea and vomiting at 0, 6, and 12-h intervals (p<0.05), and hospital stay (p<0.001) were observed in the Pecs group compared with the control group. Furthermore, data obtained from patients receiving the block from the surgeon showed comparable benefits with no complications. CONCLUSION: Interfascial plane blocks may be an important alternative protocol in MRM, enhancing patient safety and cost benefits. Improvements in cross-disciplinary expertise through flexibility in the training of professionals with other backgrounds may provide effective analgesia and favorable outcomes.

Development and clinical significance of the musculus dorsoepitrochlearis in men.

Musculus dorsoepitrochlearis is a typical muscle variation, which, if in full extent, is represented by the muscular or fibromuscular slip detached from the anteroinferior border of the musculus latissimus dorsi. It passes over the axilla under the axillary fascia crossing the medial side of the brachial plexus and continues as a septum intermusculare mediale brachii distally to the medial epicondyle of humerus. Its full extent is rarely developed-the connection into the intermuscular septum being mostly absent. Muscular slips from the musculus latissimus then insert on various structures in the axilla, often on the crest of greater tubercle of humerus or into the musculus pectoralis major (this variation is known as the axillary arch of Langer) or to other neighboring structures (coracoid process, fasciae of muscles). In our observations, 209 patients with traumatic lesions of the brachial plexus underwent surgical procedure. The presence of the musculus dorsoepitrochlearis has been observed. It was found in the form of various slips from the musculus latissimus dorsi in 4 patients. In 3 of those 4 patients, the innervation was derived from the nervus thoracodorsalis. We also presented 2 case reports of patients with clinical symptoms caused by compression of nerves in the axilla by the dorsoepitrochlear strip.

Antiarrhythmic effects of stimulating the left dorsal branch of the thoracic nerve in a canine model of paroxysmal atrial tachyarrhythmias.

BACKGROUND: Stellate ganglion nerve activity (SGNA) precedes paroxysmal atrial tachyarrhythmia (PAT) episodes in dogs with intermittent rapid left atrial (LA) pacing. The left dorsal branch of the thoracic nerve (LDTN) contains sympathetic nerves originating from the stellate ganglia. OBJECTIVE: The purpose of this study was to test the hypothesis that high-frequency electrical stimulation of the LDTN can cause stellate ganglia damage and suppress PATs. METHODS: We performed long-term LDTN stimulation in 6 dogs with and 2 dogs without intermittent rapid LA pacing while monitoring SGNA. RESULTS: LDTN stimulation reduced average SGNA from 4.36 µV (95% confidence interval [CI] 4.10-4.62 µV) at baseline to 3.22 µV (95% CI 3.04-3.40 µV) after 2 weeks (P = .028) and completely suppressed all PAT episodes in all dogs studied. Tyrosine hydroxylase staining showed large damaged regions in both stellate ganglia, with increased percentages of tyrosine hydroxylase-negative cells. The terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that 23.36% (95% CI 18.74%-27.98%) of ganglion cells in the left stellate ganglia and 11.15% (95% CI 9.34%-12.96%) ganglion cells in the right stellate ganglia were positive, indicating extensive cell death. A reduction of both SGNA and heart rate was also observed in dogs with LDTN stimulation but without rapid LA pacing. Histological studies in the 2 dogs without intermittent rapid LA pacing confirmed the presence of extensive stellate ganglia damage, along with a high percentage of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. CONCLUSION: LDTN stimulation damages both left and right stellate ganglia, reduces left SGNA, and is antiarrhythmic in this canine model of PAT.

"Isolated long thoracic nerve palsy": More than meets the eye.

INTRODUCTION: Two main hypotheses have been proposed for the pathophysiology of long thoracic nerve (LTN) palsy: nerve compression and nerve inflammation. We hypothesized that critical reinterpretation of electrodiagnostic (EDX) studies and MRIs of patients with a diagnosis of non-traumatic isolated LTN palsy could provide insight into the pathophysiology and, potentially, the treatment. MATERIAL AND METHODS: A retrospective review was performed of all patients with a diagnosis of non-traumatic isolated LTN palsy and an EDX and brachial plexus or shoulder MRI studies performed at our institution. The original EDX studies and MR examinations were reinterpreted by a neuromuscular neurologist and musculoskeletal radiologist, respectively, both blinded to our hypothesis. RESULTS: Seven patients met the inclusion criteria as having a non-traumatic isolated LTN palsy. Upon reinterpretation, all of them were found to have findings not consistent with an isolated LTN. On physical examination, three of them (43%) presented with weakness in muscles not innervated by the LTN. Four of them (57%) had additional EDX abnormalities beyond the distribution of the LTN. Five of them (71%) had MRI evidence of enlargement of nerves or denervation atrophy of muscles outside the innervation of the LNT, without evidence of compression of the LTN in the middle scalene muscle. CONCLUSION: In our series, all 7 patients, originally diagnosed as having an isolated LTN, on reinterpretation, were found to have a more diffuse muscle/nerve involvement pattern, without MR findings to suggest nerve compression. These data strongly support an inflammatory pathophysiology.

The Cardioprotective Effects of Late-Phase Remote Preconditioning of Trauma Depends on Neurogenic Pathways and the Activation of PKC and NF-κB (But Not iNOS) in Mice.

BACKGROUND: A superficial abdominal surgical incision elicits cardioprotection against cardiac ischemia-reperfusion (I/R) injury in mice. This process, called remote preconditioning of trauma (RPCT), has both an early and a late phase. Previous investigations have demonstrated that early RPCT reduces cardiac infarct size by 80% to 85%. We evaluated the cardioprotective and molecular mechanisms of late-phase RPCT in a murine I/R injury model. METHODS: Wild-type mice, bradykinin (BK) 2 receptor knockout mice, 3M transgenic mice (nuclear factor κB [NF-κb] repressor inhibitor of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha [IκBα((S32A, S36A, Y42F))]), and inducible nitric oxide synthase (iNOS) knockout mice were analyzed using a previously established I/R injury model. A noninvasive abdominal surgical incision was made 24 hours prior to I/R injury and the infarct size was determined at 24 hours post-I/R injury. RESULTS: The results indicated that a strong cardioprotective effect occurred during late-phase RPCT (58.42% ± 1.89% sham vs 29.41% ± 4.00% late RPCT, mean area of the infarct divided by the mean area of the risk region; P ≤ .05; n = 10). Furthermore, pharmacological intervention revealed the involvement of neurogenic signaling in the beneficial effects of late RPCT via sensory and sympathetic thoracic nerves. Pharmacological experiments in transgenic mice-implicated BK receptors, ß-adrenergic receptors, protein kinase C, and NF-κB but not iNOS signaling in the cardioprotective effects of late RPCT. CONCLUSION: Late RPCT significantly decreased myocardial infarct size via neurogenic transmission and various other signaling pathways. This protective mechanism differentiates late and early RPCT. This study describes a new cardiac I/R injury prevention method and refines the concept of RPCT.

The Erector Spinae Plane Block: A Novel Analgesic Technique in Thoracic Neuropathic Pain.

Thoracic neuropathic pain is a debilitating condition that is often poorly responsive to oral and topical pharmacotherapy. The benefit of interventional nerve block procedures is unclear due to a paucity of evidence and the invasiveness of the described techniques. In this report, we describe a novel interfascial plane block, the erector spinae plane (ESP) block, and its successful application in 2 cases of severe neuropathic pain (the first resulting from metastatic disease of the ribs, and the second from malunion of multiple rib fractures). In both cases, the ESP block also produced an extensive multidermatomal sensory block. Anatomical and radiological investigation in fresh cadavers indicates that its likely site of action is at the dorsal and ventral rami of the thoracic spinal nerves. The ESP block holds promise as a simple and safe technique for thoracic analgesia in both chronic neuropathic pain as well as acute postsurgical or posttraumatic pain.