Nerve ultrasound in Friedreich's Ataxia: enlarged nerves as a biomarker of disease severity

OBJECTIVE

In Friedreich's ataxia research, the focus is on discovering treatments and biomarkers to assess disease severity and treatment effects. Our study examines high-resolution nerve ultrasound in these patients, seeking correlations with established clinical markers of disease severity.

METHOD

Ten patients with Friedreich's Ataxia underwent a comprehensive clinical assessment with established scales (SARA, FARS, mFARS, INCAT, ADL 0-36, IADL). Additionally, they underwent nerve conduction studies and high-resolution nerve ultrasound. Quantitative evaluation of nerve cross-sectional area, conducted at 24 nerve sites using high-resolution nerve ultrasound, was compared with data obtained from 20 healthy volunteers.

RESULTS

All the patients had a severe sensory axonal neuropathy. High-resolution nerve ultrasound showed significant increase, in cross sectional area, of median and ulnar nerves at the axilla and arm. The cumulative count of affected nerve sites was directly associated with clinical disability, as determined by SARA, FARS, mFARS, ADL 0-36, and INCAT score, while displaying an inverse correlation with IADL.

CONCLUSIONS

Our study shows that high-resolution ultrasound reveals notable nerve abnormalities, primarily in the upper limbs of patients diagnosed with Friedreich's Ataxia. The observed correlation between these nerve abnormalities and clinical disability scales indicates the potential use of this technique as a biomarker for evaluating disease severity and treatment effects.

SIGNIFICANCE

Nerve Ultrasound is a potential biomarker of disease severity in Friedreich's Ataxia.

Predicting value for incomplete recovery in Bell's palsy of facial nerve ultrasound versus nerve conduction study

OBJECTIVE

This longitudinal study aims at assessing the predictive value of facial nerve high-resolution ultrasound (HRUS) for incomplete clinical recovery in patients with Bell's palsy, the most common facial nerve disease.

METHODS

We prospectively enrolled 34 consecutive patients with Bell's palsy. All patients underwent neurophysiological testing (including facial nerve conduction study) and HRUS evaluations 10-15 days (T1), one month (T2), and three months (T3) after the onset of Bell's palsy. Patients who did not experience complete recovery within three months were also evaluated after six months (T4). We have then compared the accuracy of HRUS with that of the facial nerve conduction study in predicting incomplete clinical recovery at three and six months.

RESULTS

At T1, the facial nerve diameter, as assessed with HRUS, was larger on the affected side than on the normal side, particularly in patients with incomplete recovery at T2, T3 and T4. ROC curve analysis, however, showed that the facial nerve diameter at T1 had a lower predictive value than the facial nerve conduction study for an incomplete clinical recovery at three (T3) and six (T4) months. Still, the facial nerve diameter asymmetry, as assessed with HRUS, had a relatively high negative predictive value (thus indicating a strong association between normal HRUS examination and a good prognosis).

CONCLUSIONS

Although HRUS shows abnormally increased facial nerve diameter in patients in the acute phase of Bell's palsy, the predictive value of this technique for incomplete clinical recovery at three and six months is lower than that of the nerve conduction study.

SIGNIFICANCE

Nerve ultrasound has a low predictive value for incomplete clinical recovery in patients with Bell's Palsy.

Modulation of the spinal N13 SEP component by high- and low-frequency electrical stimulation. Experimental pain models matter

OBJECTIVE

The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of cervical dorsal horn neurons. Neurophysiological studies in healthy participants showed that capsaicin-induced central sensitization causes an increase of the N13 SEP amplitude. Consequently, in human research, this spinal component may serve as a valuable readout of central sensitization. In this study, we wanted to verify if the sensitivity of the N13 SEP for detecting central sensitization is consistent across different experimental pain models inducing central sensitization and secondary hyperalgesia, namely high and low-frequency electrical stimulation (HFS and LFS).

METHODS

In 18 healthy participants, we recorded SEP after bilateral ulnar nerve stimulation before and after secondary hyperalgesia was induced through HFS and LFS applied on the ulnar nerve territory of the hand of one side. The area of secondary hyperalgesia was mapped with a calibrated 128-mN pinprick probe, and the mechanical pain sensitivity with three calibrated 16-64-256-mN pinprick probes.

RESULTS

Although both HFS and LFS successfully induced secondary hyperalgesia only LFS increased the amplitude of the N13 SEP.

CONCLUSIONS

These findings suggest that the sensitivity of the N13 SEP for detecting dorsal horn excitability changes may critically depend on the different experimental pain models.

SIGNIFICANCE

Our results indicate that LFS and HFS could trigger central sensitization at the dorsal horn level through distinct mechanisms, however this still needs confirmation by replication studies.

Clinical criteria and diagnostic assessment of fibromyalgia: position statement of the Italian Society of Neurology-Neuropathic Pain Study Group

BACKGROUND

The role of central and/or peripheral nervous system dysfunction is basically fundamental in fibromyalgia.

AIM

The aim of this position statement on behalf of the Neuropathic Pain Study Group of the Italian Society of Neurology is to give practical guidelines for the clinical and instrumental assessment of fibromyalgia (FM) in the neurological clinical practice, taking into consideration recent studies.

METHODS

Criteria for study selection and consideration were original studies, case-controls design, use of standardized methodologies for clinical practice, and FM diagnosis with ACR criteria (2010, 2011, 2016).

RESULTS

ACR criteria were revised. For diagnostic procedure of small-fiber pathology, 47 studies were totally considered. Recent diagnostic criteria should be applied (ACR, 2016). A rheumatologic visit seems mandatory. The involvement of small fibers should request at least 2 among HRV + SSR and/or laser-evoked responses and/or skin biopsy and/or corneal confocal microscopy, eventually followed by monitoring of metabolic and/or immunological/ and or/paraneoplastic basis, to be repeated at 1-year follow-up.

CONCLUSIONS

The correct diagnostic approach to FM could promote the exclusion of the known causes of small-fiber impairment. The research toward common genetic factors would be useful to promote a more specific therapeutic approach.

The diagnostic accuracy of the Small Fiber Neuropathy Symptoms Inventory Questionnaire (SFN-SIQ) for identifying pure small fiber neuropathy

BACKGROUND AND AIMS

A definite diagnosis of pure small fiber neuropathy (SFN) relies on specific diagnostic testing, such as skin biopsy, quantitative sensory testing (QST), and nociceptive evoked potentials, which require considerable resources that may not be widely available. Accordingly, diagnostic tools with easy implementation in non-specialist centers are warranted to identify patients who require second-level diagnostic tests. In this study, we aimed to test the accuracy of the Small Fiber Neuropathy Symptoms Inventory Questionnaire (SFN-SIQ) in diagnosing pure SFN.

METHODS

We enrolled 86 patients with suspected pure SFN. In these patients, we calculated the diagnostic accuracy of the SFN-SIQ using a combination of clinical examination, quantitative sensory testing, and skin biopsy as a reference standard.

RESULTS

We found that the SFN-SIQ showed an excellent ability to discriminate between patients with and without pure SFN, with 86% sensitivity and 70% specificity in the diagnosis of pure SFN.

INTERPRETATION

Our study providing the diagnostic yield of the SFN-SIQ for pure SFN diagnosis suggests that this questionnaire might be used to screen patients with suspected SFN and identify those requiring second-level diagnostic tests such as QST, skin biopsy, or nociceptive evoked potentials. This article is protected by copyright. All rights reserved.

P37 DIAGNOSIS AND TREATMENT OF HUMORAL REJECTION IN HEART–TRANSPLANT PATIENTS: SINGLE CENTER EXPERIENCE

Introduction

Heart Transplantation remains the gold standard treatment for Advanced Heart Failure patients. Antibody–mediated humoral rejection (AMR) is one of the main causes of medium and long–term morbility and mortality. Success, therefore, is strictly connected to the possibility of modulating immune response in the recipient through innovative diagnostic approaches of immunosuppression–therapy tailoring.

Method

Since 2019, San Camillo Hospital’s Heart Transplant Center in Rome has adopted a new integrated protocol for early diagnosis and treatment for humoral rejection which consists of clinical, instrumental and laboratory monitoring through Solid Phase Flow Cytometric Techniques in order to identify Donor Specific Anti–HLA antibodies (DSA) both fixing and not fixing complement (cytotoxicity).

Results

113 transplant patients were studied, resulted negative in prospective crossmatch at the time of surgery. Post–transplant DSA production has been monitored according to ISHLT guidelines in 1, 3, 6, 12 months’–time and, afterwards, once a year or after evidence of clinical symptoms or echocardiographic signs of graft disfunction associated always with biopsy. During the monitored period, 32 patients showed post–transplant DSA: 2 pz (6%) Class I, 16 (50%) Class II, DSA and the last 14 patients (44%) both Class I and II DSA. The capability of fixing complement (cytotoxicity) was evaluated in 19 patients. In 13 cases (68%) DSAs resulted positive for the specific test used (LSA–C1Q). In the aforementioned subgroup AMR incidence was of 23%; no AMR cases were found in the DSA C1q negative group. 3 patients showed clinical–functional deterioration and echocardiographic and bioptical alterations. Usage of apheretic treatment and re–modulation of immunosoppression therapy (FK, MMF or Everolimus) resulted in important reduction in DSAs amount, clinical recovery and echocardiocraphic signs of improvement.

Conclusions

The adopted protocol for monitoring and diagnosis of humoral rejection resulted in early identification of patients at higher risk of early graft failure. This leads to specific diagnostic and therapeutic strategies to improve long–term outcome.

How different experimental models of secondary hyperalgesia change the nociceptive flexion reflex

OBJECTIVE

In this neurophysiological study in healthy humans, we assessed how central sensitization induced by either high-frequency stimulation (HFS) or topical capsaicin application modulates features of the RIII reflex response. The ability of these stimuli to engage the endogenous pain modulatory system was also tested.

METHODS

In 26 healthy participants we elicited an RIII reflex using suprathreshold stimulation of the sural nerve. Subsequently HFS or capsaicin were applied to the foot and the RIII reflex repeated after 15 minutes. Contact heating of the volar forearm served as the heterotopic test stimulus to probe activation of the endogenous pain modulatory system.

RESULTS

HFS significantly reduced the pain threshold by 29% and the RIII reflex threshold by 20%. Capsaicin significantly reduced the pain threshold by 17% and the RIII reflex threshold by 18%. Both HFS and capsaicin left RIII reflex size unaffected. Numerical Rating Scale (NRS) pain scores elicited by the heterotopic noxious heat stimulus were unaffected by capsaicin and slightly increased by HFS.

CONCLUSIONS

HFS and capsaicin similarly modulated the pain threshold and RIII reflex threshold, without a concomitant inhibitory effect of the endogenous pain modulatory system.

SIGNIFICANCE

Our neurophysiological study supports the use of the RIII reflex in investigating central sensitization in humans.

Modulation of the N13 component of the somatosensory evoked potentials in an experimental model of central sensitization in humans

The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of dorsal horn neurons. In this neurophysiological study, we aimed to verify whether N13 SEP might reflect excitability changes of dorsal horn neurons during central sensitization. In 22 healthy participants, we investigated how central sensitization induced by application of topical capsaicin to the ulnar nerve territory of the hand dorsum modulated N13 SEP elicited by ulnar nerve stimulation. Using a double-blind placebo-controlled crossover design, we also tested whether pregabalin, an analgesic drug with proven efficacy on the dorsal horn, influenced capsaicin-induced N13 SEP modulation. Topical application of capsaicin produced an area of secondary mechanical hyperalgesia, a sign of central sensitization, and increased the N13 SEP amplitude but not the peripheral N9 nor the cortical N20-P25 amplitude. This increase in N13 SEP amplitude paralleled the mechanical hyperalgesia and persisted for 120 min. Pregabalin prevented the N13 SEP modulation associated with capsaicin-induced central sensitization, whereas capsaicin application still increased N13 SEP amplitude in the placebo treatment session. Our neurophysiological study showed that capsaicin application specifically modulates N13 SEP and that this modulation is prevented by pregabalin, thus suggesting that N13 SEP may reflect changes in dorsal horn excitability and represent a useful biomarker of central sensitization in human studies.

AB0052 ROLE OF TRAINED IMMUNITY AND IMMUNOMETABOLISM IN THE PATHOGENESIS OF ERDHEIM-CHESTER DISEASE

Background:

Erdheim-Chester disease (ECD) is a chronic inflammatory disease characterized by infiltration of bone and other tissues by foamy macrophages. These cells exhibit activating mutations along the MAPK pathway, most commonly BRAFV600E, and increased production of pro-inflammatory cytokines. Although this dual neoplastic-inflammatory nature of ECD has long fascinated scientists, the mechanistic link between these two features remains elusive. We hypothesized that Trained Immunity (TI), a pro-inflammatory cell program physiologically elicited in monocytes/macrophages upon activation of the MAPK pathway, might represent the missing link between oncogenic transformation and pro-inflammatory activation in ECD.

Objectives:

In this study, we aimed at determining the role of TI in the pathogenesis of ECD, and to evaluate the therapeutic potential of targeting this mechanism for the treatment of inflammation.

Methods:

We developed innovative models to study ECD pathogenesisin vitro(based on lentiviral transduction and ectopic expression of BRAFV600E in primary human monocytes), as well asex vivo(3D culture of ECD tissue biopsies in bioreactor). Functional and mechanistic features of TI, including typical changes in cell energy metabolism and epigenetics, were investigated by assessing I) cytokine and lactate production; II) mitochondrial respiration with Seahorse flux analyzer; III) glucose, glutamine and cholesterol metabolism with unbiased and targeted metabolomics analyses; IV) epigenetic changes with ChIP PCR; V) transcriptome changes with RNA sequencing.

Results:

Activation of the MAPK pathway induced by BRAFV600E in macrophages induces changes in the epigenetic and gene expression landscape, cell energy metabolism, and cytokine production characteristic of TI. In particular, changes in cell energy metabolism of macrophages are characterized by increased glycolysis, glutamine metabolism, and cholesterol synthesis. This metabolic rewiring is needed to sustain rampant, constitutive production of pro-inflammatory cytokines.

Conclusion:

A role emerges for TI in the pathogenesis and pro-inflammatory activation of ECD. However, maladaptive activation of this mechanism is likely common to the pathogenesis of other inflammatory and rheumatologic diseases. Since drugs targeting TI programs are already entering the clinical arena, the identification of this mechanism in the pathogenesis of inflammatory and rheumatologic conditions may promptly translate into novel, effective treatment options for affected patients.

Disclosure of Interests:

Riccardo Biavasco Employee of: Bluebird, Raffaella Molteni: None declared, Davide Stefanoni: None declared, Marina Ferrarini: None declared, Elisabetta Ferrero: None declared, Simone Cenci: None declared, Simone Cardaci: None declared, Alessandra Boletta: None declared, Laura Cassina: None declared, Gianfranco Di Stefano: None declared, Jorge Dominguez Andres: None declared, Claudio Doglioni: None declared, Travis Nemkov: None declared, Ivan Merelli: None declared, Angelo D’Alessandro: None declared, Eugenio Montini: None declared, Mihai Netea: None declared, Lorenzo Dagna: None declared, Giulio Cavalli Consultant of: SOBI, Pfizer, Sanofi, Novartis, Paid instructor for: SOBI, Novartis, Speakers bureau: SOBI, Novartis

A pain in the skin. Regenerating nerve sprouts are distinctly associated with ongoing burning pain in patients with diabetes

BACKGROUNDS

Patients with diabetic polyneuropathy commonly suffer from ongoing burning pain and dynamic mechanical allodynia. In this clinical and skin biopsy study, we aimed at assessing how intraepidermal regenerating nerve sprouts are associated with these two types of pain.

METHODS

We consecutively enrolled 85 patients with diabetic polyneuropathy. All patients underwent skin biopsy at the distal leg. Intraepidermal nerve fibres were immunostained with the anti-protein gene product 9.5 (PGP9.5) to quantify all intraepidermal nerve fibres, and the growth-associated protein 43 (GAP43) to quantify regenerating nerve sprouts.

RESULTS

We found that the GAP43-stained intraepidermal nerve fibre density and the ratio GAP43/PGP9.5 were significantly higher in patients with ongoing burning pain than in those without. The area of receiver operating characteristic (ROC) curve for the ratio GAP43/PGP9.5 was 0.74 and yielded a sensitivity and specificity for identifying ongoing burning pain of 72% and 71%, respectively. Conversely, although the density of PGP9.5 and GAP43 intraepidermal nerve fibre was higher in patients with dynamic mechanical allodynia than in those without, this difference was statistically weak and the ROC curve analysis of skin biopsy variables for this type of pain failed to reach the statistical significance.

CONCLUSION

Our clinical and skin biopsy study showed that ongoing burning pain was strongly associated with regenerating sprouts, as assessed with GAP43 immunostaining. This finding improves our understanding on the mechanisms underlying neuropathic pain in patients with diabetic polyneuropathy and suggests that the GAP43/PGP 9.5 ratio might be used as an objective marker for ongoing burning pain due to regenerating sprouts.

SIGNIFICANCE

Our skin biopsy study showing that regenerating sprouts, as assessed with GAP43-staining, were strongly associated with ongoing burning pain, improves our knowledge on the mechanisms underlying neuropathic pain in patients with diabetes.

Author Correction to: L-Acetyl-carnitine in Patients with Carpal Tunnel Syndrome: Effects on Nerve Protection, Hand Function and Pain

In the original publication the name of third author was incorrectly published.

Selenium Concentrations and Mortality among Community-Dwelling Older Adults: Results from IlSIRENTE Study

BACKGROUND

Selenium has a wide range of pleiotropic effects, influencing redox homeostasis, thyroid hormone metabolism, and protecting from oxidative stress and inflammation. Serum selenium levels are reduced in the older population.

OBJECTIVES

to investigate the association of serum selenium levels with all-cause mortality in a sample of community-dwelling older adults.

DESIGN AND SETTING

Data are from the 'Invecchiamento e Longevità nel Sirente' (Aging and Longevity in the Sirente geographic area, ilSIRENTE) study, a prospective cohort study that collected information on individuals aged 80 years and older living in an Italian mountain community (n=347). The main outcome was risk of death after ten years of follow-up.

PARTICIPANTS AND MEASUREMENTS

Participants were classified according to the median value of selenium (105.3 μg/L) in two groups: high selenium and low selenium.

RESULTS

A total of 248 deaths occurred during a 10-year follow-up. In the unadjusted model, low levels of selenium was associated with increased mortality (HR, 0.66; 95% CI 0.51-0.85). After adjusting for potential confounders the relationship remained significant (HR, 0.71; 95% CI 0.54-0.92).

CONCLUSIONS

Low serum levels of selenium are associated with reduced survival in elderly, independently of age and other clinical and functional variables.

Genetic deletion of the bacterial sensor NOD2 improves murine Crohn's disease-like ileitis independent of functional dysbiosis

Although genetic polymorphisms in NOD2 (nucleotide-binding oligomerization domain-containing 2) have been associated with the pathogenesis of Crohn's disease (CD), little is known regarding the role of wild-type (WT) NOD2 in the gut. To date, most murine studies addressing the role of WT Nod2 have been conducted using healthy (ileitis/colitis-free) mouse strains. Here, we evaluated the effects of Nod2 deletion in a murine model of spontaneous ileitis, i.e., the SAMP1Yit/Fc (SAMP) strain, which closely resembles CD. Remarkably, Nod2 deletion improved both chronic cobblestone ileitis (by 50% assessed, as the % of abnormal mucosa at 24 wks of age), as well as acute dextran sodium sulfate (DSS) colitis. Mechanistically, Th2 cytokine production and Th2-transcription factor activation (i.e., STAT6 phosphorylation) were reduced. Microbiologically, the effects of Nod2 deletion appeared independent of fecal microbiota composition and function, assessed by 16S rRNA and metatranscriptomics. Our findings indicate that pharmacological blockade of NOD2 signaling in humans could improve health in Th2-driven chronic intestinal inflammation.

L-Acetyl-carnitine in Patients with Carpal Tunnel Syndrome: Effects on Nerve Protection, Hand Function and Pain

BACKGROUND AND AIM

L-Acetyl-carnitine (LAC) exerts an energetic effect on nerves and muscles. Recently, preclinical experiments have demonstrated a central anti-nociceptive action.

OBJECTIVE

Our objective was to assess the effects of LAC on neuroprotection, pain, and function in carpal tunnel syndrome (CTS), a very frequent chronic compressive neuropathy.

METHODS

In a multicentre, examiner-blinded, clinical and neurophysiological 4-month study, we enrolled 82 patients and examined 120 hands with CTS of mild to moderate severity. Patients were assessed at baseline and 10, 60 and 120 days after treatment with LAC 500 mg twice daily (BID). All patients underwent a conduction study of the median nerve, the Boston Carpal Tunnel Questionnaire (BCTQ) and the Neuropathic Pain Symptom Inventory (NPSI). The primary endpoint was the sensory conduction velocity (SCV) of the median nerve.

RESULTS

The primary endpoint was met, with significant improvement of the SCV (P < 0.0001). All sensory neurophysiological measures also significantly improved. BCTQ score changed significantly (P < 0.0001), with a greater improvement in the symptom component. Nine of the NPSI types of pain, particularly squeezing and pressure pain and pain evoked by pressure, showed a significant reduction (P < 0.0001).

CONCLUSIONS

Our clinical and neurophysiological study indicated that 4 months of treatment with LAC exerted a neuroprotective effect. LAC reduced pain in patients with mild and moderate CTS, a result that is possibly due to both its neuroprotective action and its central anti-nociceptive properties. Clinical Trials Registration code: EudraCT 2014-002289-62.

Precursory changes in seismic velocity for the spectrum of earthquake failure modes

Temporal changes in seismic velocity during the earthquake cycle have the potential to illuminate physical processes associated with fault weakening and connections between the range of fault slip behaviors including slow earthquakes, tremor and low frequency earthquakes1. Laboratory and theoretical studies predict changes in seismic velocity prior to earthquake failure2, however tectonic faults fail in a spectrum of modes and little is known about precursors for those modes3. Here we show that precursory changes of wave speed occur in laboratory faults for the complete spectrum of failure modes observed for tectonic faults. We systematically altered the stiffness of the loading system to reproduce the transition from slow to fast stick-slip and monitored ultrasonic wave speed during frictional sliding. We find systematic variations of elastic properties during the seismic cycle for both slow and fast earthquakes indicating similar physical mechanisms during rupture nucleation. Our data show that accelerated fault creep causes reduction of seismic velocity and elastic moduli during the preparatory phase preceding failure, which suggests that real time monitoring of active faults may be a means to detect earthquake precursors.

Vitamin D3 inhibits TNFα-induced latent HIV reactivation in J-LAT cells

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is known to suppress NF-kB activity by interfering with its pathways. The aim of this study was to investigate the ability of 1,25(OH)2D3 in reducing the reactivation of the HIV virus J-LAT cells, an established model of latently infected cells, which were treated with TNFalpha (100 ng/ml) for 2 h with or without 24 h 1,25(OH)2D3 (100 nM) pretreatment. Reactivation of HIV RNA in J-LAT was evaluated in terms of green fluorescent protein (GFP) expression. The same experimental setting was repeated on T cells from HIV-infected patients. Treatment with TNFalpha was associated with a 16 % increase in GFP+ cells and a five-fold increase in unspliced HIV RNA expression (p < 0.04). Pretreatment of J-LAT cells with 1,25(OH)2D3 for 24 h followed by TNFalpha (100 ng/ml) for 2 h reduced the percentage of GFP+ cells by 8 %; moreover, a 2.4-fold decrease in unspliced HIV RNA expression was observed (p < 0.002). In T cells from patients, treatment with TNFalpha significantly increased unspliced HIV RNA expression (sixfold increase, p < 0.02), whereas prestimulation with 1,25(OH)2D3 reduced its expression (2.5-fold decrease, p < 0.02) compared to controls.1,25(OH)2D3 is able to reduce the ability of TNFalpha to upregulate the transcription of HIV RNA from latently infected cells. These data provide further understanding of the pathogenic mechanisms regulating viral reactivation from latent reservoirs, along with new insight in viral internalization.

Clinical, neurophysiological, and skin biopsy findings in peripheral neuropathy associated with hepatitis C virus-related cryoglobulinemia

Hepatitis C virus (HCV)-related cryoglobulinemia commonly causes disabling complications including peripheral neuropathy and neuropathic pain. In this prospective clinical, neurophysiological, and skin biopsy study we aimed at assessing clinical characteristics and risk factors of peripheral neuropathy and neuropathic pain in patients with HCV-related cryoglobulinemia. We enrolled 69 consecutive patients with HCV-related cryoglobulinemia. We diagnosed neuropathic pain with the DN4 (Neuropathic Pain Diagnostic) questionnaire, and rated the various neuropathic pains with the Neuropathic Pain Symptom Inventory (NPSI). All patients underwent a standard nerve conduction study to assess Aβ-fiber function, laser-evoked potentials to assess Aδ-fiber function, and skin biopsy to assess C-fiber terminals. Of the 69 patients studied, 47 had a peripheral neuropathy, and 29 had neuropathic pain. Patients with peripheral neuropathy were older than those without (P < 0.0001). While peripheral neuropathy was significantly associated with the duration of HCV infection (P < 0.01), it was unrelated to the duration of cryoglobulinemia and cryocrit (P > 0.5). The severity of peripheral neuropathy significantly correlated with the duration of HCV infection (P < 0.05). Laser-evoked potential amplitudes were significantly lower in patients with than in those without neuropathic pain (P < 0.05). Conversely, no difference was found in nerve conduction study and skin biopsy findings (P > 0.05). Our findings show that peripheral neuropathy is related to age and HCV infection, rather than to cryoglobulinemia, and neuropathic pain is associated with damage to nociceptive pathways as assessed with laser-evoked potentials; this might be useful for designing more effective clinical interventions for these common HCV related-cryoglobulinemia complications.

H-coil repetitive transcranial magnetic stimulation for pain relief in patients with diabetic neuropathy

BACKGROUND

Painful neuropathy is associated with plasticity changes in the nervous system. Standard repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique used to study changes in cortical excitability and to inhibit pain perception. Deep rTMS is a newer development that allows direct activation of deeper neuronal populations, by a unique coil design termed the H-coil. This study was designed to assess whether deep rTMS applied over the motor cortical lower-limb representation relieves pain in patients with diabetic neuropathy.

METHODS

Patients were randomly assigned to receive daily real or sham H-coil rTMS for 5 consecutive days. After a 5-week washout period, they crossed over to the alternative treatment for additional 5 days (according to a crossover study design). Outcome measures were changes in the visual analogue scale (VAS) for pain and in area and threshold of RIII nociceptive flexion reflex (RIII reflex).

RESULTS

Of the 25 patients randomized, 23 completed the study. After real rTMS, the VAS scores decreased significantly (p=0.01), and so did RIII reflex area (p<0.01), while no significant effects in these variables were induced by the sham rTMS treatment. The rTMS-induced changes in the outcome measures disappeared about 3 weeks after stimulation. All patients tolerated stimulation well.

CONCLUSIONS

Deep H-coil rTMS provides pain relief in patients with diabetic neuropathy. This innovative technique can induce a therapeutic effect on brain areas that otherwise remain difficult to target. rTMS may produce its analgesic effects, inducing motor cortex plasticity and activating descending inhibitory pain control systems.

Peripheral nociceptor sensitization mediates allodynia in patients with distal symmetric polyneuropathy

Patients with painful neuropathy frequently complain of pain in response to normally non-painful brushing, namely dynamic mechanical allodynia. Despite many animal studies suggesting that allodynia arises when the spontaneous firing in damaged nociceptive afferents sensitise second-order nociceptive neurons to Aβ-fibre input, no studies have sought to confirm this mechanism by investigating Aβ-fibre sparing in human patients with allodynia. In this study we compared data from Aβ-fibre-mediated nerve conduction studies and nociceptive-fibre-mediated laser-evoked potentials (LEPs) in 200 patients with distal symmetric polyneuropathy (114 with neuropathic pain, 86 without). Of the 114 patients with painful neuropathy studied, 44 suffered from allodynia. Whereas no statistical difference was found in nerve conduction study data between patients with and without allodynia, LEP amplitudes were larger in patients with allodynia than in those without (P < 0.01 by Mann-Whitney U test). The lack of difference in NCS data between patients with and without allodynia suggest that this type of pain, rather than arising through second-order nociceptive neuron sensitization to Aβ-fibre input, might reflect a reduced mechanical threshold in sensitised intraepidermal nociceptive nerve terminals.

Galloflavin, a new lactate dehydrogenase inhibitor, induces the death of human breast cancer cells with different glycolytic attitude by affecting distinct signaling pathways

Galloflavin (GF), a recently identified lactate dehydrogenase inhibitor, hinders the proliferation of cancer cells by blocking glycolysis and ATP production. The aim of the present experiments was to study the effect of this compound on breast cancer cell lines reproducing different pathological subtypes of this tumor: MCF-7 (the well differentiated form), MDA-MB-231 (the aggressive triple negative tumor) and MCF-Tam (a sub-line of MCF-7 with acquired tamoxifen resistance). We observed marked differences in the energetic metabolism of these cell lines. Compared to MCF-7 cells, both MDA-MB-231 and MCF-Tam cells exhibited higher LDH levels and glucose uptake and showed lower capacity of oxygen consumption. In spite of these differences, GF exerted similar growth inhibitory effects. This result was explained by the finding of a constitutively activated stress response in MDA-MB-231 and MCF-Tam cells, which reproduce the poor prognosis tumor forms. As a further proof, different signaling pathways were found to be involved in the antiproliferative action of GF. In MCF-7 cells we observed a down regulation of the ERα-mediated signaling needed for cell survival. On the contrary, in MCF-Tam and MDA-MB-231 cells growth inhibition appeared to be contributed by an oxidative stress condition. The prevalent mechanism of cell death was found to be apoptosis induction. Because of the clinical relevance of breast cancer forms having the triple negative and/or chemoresistant phenotype, our results showing comparable effects of GF even on aggressively growing cells encourage further studies to verify the potential of this compound in improving the chemotherapy of breast cancer.

Incisional hernia in day surgery: our personal experience

Incisional hernia is one of the most common complications of laparotomy. Its repair with prosthesis has enabled a considerable improvement in the outcome, significantly reducing recurrences. This study analyses the results of open hernioplasty with mesh performed as a Day Surgery procedure in 42 patients between November 2008 and October 2010. The results were good, with low postoperative morbidity and recurrences (2.4%).