Fractal Dimension as a discriminative feature for high accuracy classification in motor imagery EEG-based brain-computer interface

BACKGROUND AND OBJECTIVE

The brain-computer interface (BCI) technology acquires human brain electrical signals, which can be effectively and successfully used to control external devices, potentially supporting subjects suffering from motor impairments in the interaction with the environment. To this aim, BCI systems must correctly decode and interpret neurophysiological signals reflecting the intention of the subjects to move. Therefore, the accurate classification of single events in motor tasks represents a fundamental challenge in ensuring efficient communication and control between users and BCIs. Movement-associated changes in electroencephalographic (EEG) sensorimotor rhythms, such as event-related desynchronization (ERD), are well-known features of discriminating motor tasks. Fractal dimension (FD) can be used to evaluate the complexity and self-similarity in brain signals, potentially providing complementary information to frequency-based signal features.

METHODS

In the present work, we introduce FD as a novel feature for subject-independent event classification, and we test several machine learning (ML) models in behavioural tasks of motor imagery (MI) and motor execution (ME).

RESULTS

Our results show that FD improves the classification accuracy of ML compared to ERD. Furthermore, unilateral hand movements have higher classification accuracy than bilateral movements in both MI and ME tasks.

CONCLUSIONS

These results provide further insights into subject-independent event classification in BCI systems and demonstrate the potential of FD as a discriminative feature for EEG signals.

Fractal Time Series: Background, Estimation Methods, and Performances

Over the past 40 years, from its classical application in the characterization of geometrical objects, fractal analysis has been progressively applied to study time series in several different disciplines. In neuroscience, starting from identifying the fractal properties of neuronal and brain architecture, attention has shifted to evaluating brain signals in the time domain. Classical linear methods applied to analyzing neurophysiological signals can lead to classifying irregular components as noise, with a potential loss of information. Thus, characterizing fractal properties, namely, self-similarity, scale invariance, and fractal dimension (FD), can provide relevant information on these signals in physiological and pathological conditions. Several methods have been proposed to estimate the fractal properties of these neurophysiological signals. However, the effects of signal characteristics (e.g., its stationarity) and other signal parameters, such as sampling frequency, amplitude, and noise level, have partially been tested. In this chapter, we first outline the main properties of fractals in the domain of space (fractal geometry) and time (fractal time series). Then, after providing an overview of the available methods to estimate the FD, we test them on synthetic time series (STS) with different sampling frequencies, signal amplitudes, and noise levels. Finally, we describe and discuss the performances of each method and the effect of signal parameters on the accuracy of FD estimation.

Band-Specific Altered Cortical Connectivity in Early Parkinson's Disease and its Clinical Correlates

BACKGROUND

Functional connectivity (FC) has shown promising results in assessing the pathophysiology and identifying early biomarkers of neurodegenerative disorders, such as Parkinson's disease (PD).

OBJECTIVES

In this study, we aimed to assess possible resting-state FC abnormalities in early-stage PD patients using high-density electroencephalography (EEG) and to detect their clinical relationship with motor and non-motor PD symptoms.

METHODS

We enrolled 26 early-stage levodopa naïve PD patients and a group of 20 healthy controls (HC). Data were recorded with 64-channels EEG system and a source-reconstruction method was used to identify brain-region activity. FC was calculated using the weighted phase-lag index in θ, α, and β bands. Additionally, we quantified the unbalancing between β and lower frequencies through a novel index (β-functional ratio [FR]). Statistical analysis was conducted using a network-based statistical approach.

RESULTS

PD patients showed hypoconnected networks in θ and α band, involving prefrontal-limbic-temporal and frontoparietal areas, respectively, and a hyperconnected network in the β frequency band, involving sensorimotor-frontal areas. The θ FC network was negatively related to Non-Motor Symptoms Scale scores and α FC to the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale part III gait subscore, whereas β FC and β-FR network were positively linked to the bradykinesia subscore. Changes in θ FC and β-FR showed substantial reliability and high accuracy, precision, sensitivity, and specificity in discriminating PD and HC.

CONCLUSIONS

Frequency-specific FC changes in PD likely reflect the dysfunction of distinct cortical networks, which occur from the early stage of the disease. These abnormalities are involved in the pathophysiology of specific motor and non-motor PD symptoms, including gait, bradykinesia, mood, and cognition. © 2023 International Parkinson and Movement Disorder Society.

Current and novel infusion therapies for patients with Parkinson's disease

Advanced Parkinson's disease is characterized by periods of poor mobility, dyskinesia and progressive decline in functional independence of the affected person despite the manipulation of levodopa doses and the introduction of supplemental therapies such as catechol-O-methyl transferase inhibitors, monoamine oxidase-B inhibitors and dopamine agonists. The implementation of drug delivery systems allows to bypass problems related to irregular and often unpredictable intestinal absorption of oral levodopa, which significantly affects its bioavailability and contributes to the development and persistence of motor complications. Subcutaneous apomorphine and levodopa/carbidopa jejunal infusion systems have been available for many years and their efficacy is confirmed by randomized studies and long-term experience in many centers worldwide. Recently, a new formulation of levodopa/carbidopa infusion gel that includes the catechol-O-methyl transferase inhibitor Entacapone has been introduced to the market. The use of entacapone allows to reduce total daily dose of administered levodopa. Two different soluble formulations of levodopa/carbidopa (ND0612 and ABBV-951) have completed clinical development, and both can ensure subcutaneous delivery by a portable pump infusion system. ABBV-951 uses a foslevodopa/foscarbidopa formulation, both prodrugs to improve absorption and tolerability. Both systems provide effective improvement of motor complications and are likely to expand the therapeutic options in advanced patients. Future efforts should focus on the earlier detection of patients who are candidates for device-aided therapies, increasing appropriate referral and broadening the availability of these treatments globally.

Objective measurement versus clinician-based assessment for Parkinson's disease

INTRODUCTION

Although clinician-based assessment through standardized clinical rating scales is currently the gold standard for quantifying motor impairment in Parkinson's disease (PD), it is not without limitations, including intra- and inter-rater variability and a degree of approximation. There is increasing evidence supporting the use of objective motion analyses to complement clinician-based assessment. Objective measurement tools hold significant potential for improving the accuracy of clinical and research-based evaluations of patients.

AREAS COVERED

The authors provide several examples from the literature demonstrating how different motion measurement tools, including optoelectronics, contactless and wearable systems allow for both the objective quantification and monitoring of key motor symptoms (such as bradykinesia, rigidity, tremor, and gait disturbances), and the identification of motor fluctuations in PD patients. Furthermore, they discuss how, from a clinician's perspective, objective measurements can help in various stages of PD management.

EXPERT OPINION

In our opinion, sufficient evidence supports the assertion that objective monitoring systems enable accurate evaluation of motor symptoms and complications in PD. A range of devices can be utilized not only to support diagnosis but also to monitor motor symptom during the disease progression and can become relevant in the therapeutic decision-making process.

Assessing the interaction between L-dopa and γ-transcranial alternating current stimulation effects on primary motor cortex plasticity in Parkinson's disease

L-dopa variably influences transcranial magnetic stimulation (TMS) parameters of motor cortex (M1) excitability and plasticity in Parkinson's disease (PD). In patients OFF dopaminergic medication, impaired M1 plasticity and defective GABA-A-ergic inhibition can be restored by boosting gamma (γ) oscillations via transcranial alternating current stimulation (tACS) during intermittent theta-burst stimulation (iTBS). However, it is unknown whether L-dopa modifies the beneficial effects of iTBS-γ-tACS on M1 in PD. In this study, a PD patients group underwent combined iTBS-γ-tACS and iTBS-sham-tACS, each performed both OFF and ON dopaminergic therapy (four sessions in total). Motor evoked potentials (MEPs) elicited by single TMS pulses and short-interval intracortical inhibition (SICI) were assessed before and after iTBS-tACS. We also evaluated possible SICI changes during γ-tACS delivered alone in OFF and ON conditions. The amplitude of MEP elicited by single TMS pulses and the degree of SICI inhibition significantly increased after iTBS-γ-tACS. The amount of change produced by iTBS-γ-tACS was similar in patients OFF and ON therapy. Finally, γ-tACS (delivered alone) modulated SICI during stimulation and this effect did not depend on the dopaminergic condition of patients. In conclusion, boosting cortical γ oscillatory activity via tACS during iTBS improved M1 plasticity and enhanced GABA-A-ergic transmission in PD patients to the same extent regardless of dopaminergic state. These results suggest a lack of interaction between L-dopa and γ-tACS effects at the M1 level. The possible neural substrate underlying iTBS-γ tACS effects, that is, γ-resonant GABA-A-ergic interneurons activity, may explain our findings.

Long-term changes in short-interval intracortical facilitation modulate motor cortex plasticity and L-dopa-induced dyskinesia in Parkinson's disease

BACKGROUND

Abnormal glutamatergic neurotransmission in the primary motor cortex (M1) contributes to Parkinson's disease (PD) pathophysiology and is related to l-dopa-induced dyskinesia (LID). We previously showed that short-term treatment with safinamide, a monoamine oxidase type-B inhibitor with anti-glutamatergic properties, improves abnormally enhanced short-interval intracortical facilitation (SICF) in PD patients.

OBJECTIVE

To examine whether a long-term SICF modulation has beneficial effects on clinical measures, including LID severity, and whether these changes parallel improvement in cortical plasticity mechanisms in PD.

METHODS

We tested SICF in patients with and without LID before (S0) and after short- (14 days - S1) and long-term (12 months - S2) treatment with safinamide 100 mg/day. Possible changes in M1 plasticity were assessed using intermittent theta-burst stimulation (iTBS). Finally, we correlated safinamide-related neurophysiological changes with modifications in clinical scores.

RESULTS

SICF was enhanced at S0, and prominently in patients with LID. Safinamide normalized SICF at S1, and this effect persisted at S2. Impaired iTBS-induced plasticity was present at S0 and safinamide restored this alteration at S2. There was a significant correlation between the degree of SICF and the amount of iTBS-induced plasticity at S0 and S2. In patients with LID, the degree of SICF at S0 and S2 correlated with long-term changes in LID severity.

CONCLUSIONS

Altered SICF contributes to M1 plasticity impairment in PD. Both SICF and M1 plasticity improve after long-term treatment with safinamide. The abnormality in SICF-related glutamatergic circuits plays a role in LID pathophysiology, and its long-term modulation may prevent LID worsening over time.

Efficacy of ustekinumab in the treatment of patients with Crohn's disease with failure to previous conventional or biologic therapy: a prospective observational real-life study

Ustekinumab (UST), a human anti-IL12/23p40 monoclonal antibody, was approved by FDA and EMA for the treatment of moderate to severe Crohn's disease (CD). Whether UST is effective in inducing deep remission, including mucosal healing and transmural healing, in patients with CD in a real life setting is not completely clear. This study was performed on 92 subjects with confirmed diagnosis of moderate to severe Crohn's disease and no neoplasia. Before inclusion, all patients had been exposed and had failed to respond to conventional and/or at least one biological therapy. All patients underwent endoscopic examination and bowel MRI and ultrasonography at baseline (T0). At week 52 (T52), patients underwent colonoscopy for assessment of mucosal healing and MRI or ultrasonography for assessment of transmural healing. CDAI was used for the assessment of clinical response and clinical remission. SES-CD was used to assess endoscopic response and remission. Incidence of treatment-related adverse events (TRAEs) was recorded during the study period. Clinical response at week 52 was achieved in 38 (50.5%) patients and clinical remission in 29 (39%). Twenty-six (34%) patients showed mucosal healing, 34 (45%) showed partial endoscopic response. We observed a reduction in SES-CD of at least 50% in 34 (45%) patients as well as an SES-CD ≤ 2 in 26 (35%) patients. All patients with mucosal healing also showed transmural healing. No major TRAEs were observed during treatment. In this multicenter, real life study, we show that UST was well tolerated and effective in inducing clinical response and clinical remission in patients with moderate to severe CD who had previously failed to respond to conventional or biologic therapy. UST showed limited efficacy in inducing deep remission (i.e. mucosal+transmural healing).

The potential diagnostic and predictive role of anaplastic lymphoma kinase (ALK) gene alterations in melanocytic tumors

OBJECTIVE

Anaplastic lymphoma kinase (ALK) gene has been demonstrated to be rearranged, mutated or amplified in several haematological and solid tumors. Moreover, the use of ALK inhibitors has recently revolutionized the treatment of ALK-rearranged patients affected by non-small cell lung carcinoma. Herein we review the genetic alterations of ALK in melanocytic neoplasms described in literature, focusing on their potential diagnostic and predictive role.

MATERIALS AND METHODS

The Authors reviewed the pertinent literature through research on PubMed server was performed typing the terms "ALK", "Anaplastic lymphoma kinase", "ALKATI", "Melanoma", "Spitz", "Spitzoid".

RESULTS

ALK translocations were demonstrated in melanocytic neoplasms, particularly in acral melanoma and spitzoid tumors. ALKATI was described in primary and metastatic melanoma, indicating its early occurrence in oncogenesis, with varying immunohistochemical expression of the protein.

CONCLUSIONS

The identification of the specific type of ALK mutations could be interesting for planning biologic therapy of melanoma patients. Further studies are needed to evaluate the possibility to introduce an ALK-targeted therapy in patients affected by malignant melanoma.

The effect of gamma oscillations in boosting primary motor cortex plasticity is greater in young than older adults

OBJECTIVE

In healthy subjects, the long-term potentiation (LTP)-like plasticity of the primary motor cortex (M1) induced by intermittent theta-burst stimulation (iTBS) can be boosted by modulating gamma (γ) oscillations through transcranial alternating current stimulation (tACS). γ-tACS also reduces short-interval intracortical inhibition (SICI). We tested whether the effects of γ-tACS differ between young (YA) and older adults (OA).

METHODS

Twenty YA (27.2 ± 2.7 years) and twenty OA (65.3 ± 9.5 years) underwent iTBS-γ tACS and iTBS-sham tACS in randomized sessions. In a separate session, we delivered γ-tACS alone and recorded SICI during stimulation.

RESULTS

iTBS-sham tACS produced comparable motor evoked potential (MEP) facilitation between groups. While iTBS-γ tACS boosted MEP facilitation in both the YA and OA groups, the magnitude of its effect was significantly lower in OA. Similarly, γ-tACS-induced modulation of GABA-A-ergic neurotransmission, as tested by SICI, was reduced in OA. The effect of iTBS-γ tACS negatively correlated with the age of OA subjects.

CONCLUSIONS

Mechanisms underlying the effects of γ oscillations on LTP-like plasticity become less efficient in older adults. This could reflect age-related changes in neural elements of M1 resonant to γ oscillations, including GABA-A-ergic interneurons.

SIGNIFICANCE

The beneficial effect of γ-tACS on iTBS-induced plasticity is reduced in older adults.

LTD-like plasticity of the human primary motor cortex can be reversed by γ-tACS

BACKGROUND

Cortical oscillatory activities play a role in regulating several brain functions in humans. However, whether motor resonant oscillations (i.e. β and γ) modulate long-term depression (LTD)-like plasticity of the primary motor cortex (M1) is still unclear.

OBJECTIVE

To address this issue, we combined transcranial alternating current stimulation (tACS), a technique able to entrain cortical oscillations, with continuous theta burst stimulation (cTBS), a transcranial magnetic stimulation (TMS) protocol commonly used to induce LTD-like plasticity in M1.

METHODS

Motor evoked potentials (MEPs) elicited by single-pulse TMS, short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were evaluated before and 5, 15 and 30 min after cTBS alone or cTBS delivered during β-tACS (cTBS-β) or γ-tACS (cTBS-γ). Moreover, we tested the effects of β-tACS (alone) on short-latency afferent inhibition (SAI) and γ-tACS on SICI in order to verify whether tACS-related interneuronal modulation contributes to the effects of tACS-cTBS co-stimulation.

RESULTS

cTBS-γ turned the expected after-effects of cTBS from inhibition to facilitation. By contrast, responses to cTBS-β were similar to those induced by cTBS alone. β- and γ-tACS did not change MEPs evoked by single-pulse TMS. β-tACS reduced SAI and γ-tACS reduced SICI. However, the degree of γ-tACS-induced modulation of SICI did not correlate with the effects of cTBS-γ.

CONCLUSION

γ-tACS reverses cTBS-induced plasticity of the human M1. γ-oscillations may therefore regulate LTD-like plasticity mechanisms.

Boosting the LTP-like plasticity effect of intermittent theta-burst stimulation using gamma transcranial alternating current stimulation

BACKGROUND

Transcranial Alternating Current Stimulation (tACS) consists in delivering electric current to the brain using an oscillatory pattern that may entrain the rhythmic activity of cortical neurons. When delivered at gamma frequency, tACS modulates motor performance and GABA-A-ergic interneuron activity.

OBJECTIVE

Since interneuronal discharges play a crucial role in brain plasticity phenomena, here we co-stimulated the primary motor cortex (M1) in healthy subjects by means of tACS during intermittent theta-burst stimulation (iTBS), a transcranial magnetic stimulation paradigm known to induce long-term potentiation (LTP)-like plasticity.

METHODS

We measured and compared motor evoked potentials before and after gamma, beta and sham tACS-iTBS. While we delivered gamma-tACS, we also measured short-interval intracortical inhibition (SICI) to detect any changes in GABA-A-ergic neurotransmission.

RESULTS

Gamma, but not beta and sham tACS, significantly boosted and prolonged the iTBS-induced after-effects. Interestingly, the extent of the gamma tACS-iTBS after-effects correlated directly with SICI changes.

CONCLUSIONS

Overall, our findings point to a link between gamma oscillations, interneuronal GABA-A-ergic activity and LTP-like plasticity in the human M1. Gamma tACS-iTBS co-stimulation might represent a new strategy to enhance and prolong responses to plasticity-inducing protocols, thereby lending itself to future applications in the neurorehabilitation setting.

Association between coffee or tea drinking and Barrett's esophagus or esophagitis: an Italian study

BACKGROUND/OBJECTIVES

Only a few papers have treated of the relationship between Barrett's esophagus (BE) or erosive esophagitis (E) and coffee or tea intake. We evaluated the role of these beverages in BE and E occurrence.

SUBJECTS/METHODS

Patients with BE (339), E (462) and controls (619) were recruited. Data on coffee and tea and other individual characteristics were collected using a structured questionnaire.

RESULTS

BE risk was higher in former coffee drinkers, irrespective of levels of exposure (cup per day; ⩽1: OR=3.76, 95% CI 1.33-10.6; >1: OR=3.79, 95% CI 1.31-11.0; test for linear trend (TLT) P=0.006) and was higher with duration (>30 years: OR=4.18, 95% CI 1.43-12.3; TLT P=0.004) and for late quitters, respectively (⩽3 years from cessation: OR=5.95, 95% CI 2.19-16.2; TLT P<0.001). The risk of BE was also higher in subjects who started drinking coffee later (age >18 years: OR=6.10, 95% CI 2.15-17.3). No association was found in current drinkers, but for an increased risk of E in light drinkers (<1 cup per day OR =1.85, 95% CI 1.00-3.43).A discernible risk reduction of E (about 20%, not significant) and BE (about 30%, P<0.05) was observed in tea drinkers.

CONCLUSIONS

Our data were suggestive of a reduced risk of BE and E with tea intake. An adverse effect of coffee was found among BE patients who had stopped drinking coffee. Coffee or tea intakes could be indicative of other lifestyle habits with protective or adverse impact on esophageal mucosa.

Hyperammonemic coma in a patient with late-onset OTC deficiency

Urea Cycle Disorders ( UCD ) are among the most common genetic diseases of the metabolism and ornithine transcarbamylase deficiency (OTC), an X-linked defect is the most frequent among them. It is responsible for hyperammonemia that can lead to chronic neurological illness and potentially to death in case of delayed diagnosis and treatment. With regards to the OTC deficiency there is great clinical heterogeneity with early-onset phenotypes with mostly poor prognosis and late-onset phenotypes with a better one. In the article it is reported the case of a 8 years old patient with diagnosis of OTC deficit with late-onset phenotype. The kid was brought to our hospital because of continuous vomiting and gastro- intestinal disorders, associated with irritability and lethargy later resulted into coma. Measurement of plasma ammonia concentration, followed by measurement of plasma amino acid and urine orotic acid levels allowed to diagnose the OTC deficit, lately confirmed by molecular genetic studies. The patient has been promptly treated with Sodium Phenylbutyrate, Arginine and discontinuing the protein intake. Gradually the ammonemia value decreased, and general and neurological conditions improved with resolution of the coma. To conclude, for patients presenting unexplained neurological symptoms, confusion and decreased level of consciousness, up to coma, urea cycle disorders and in particularly OTC deficiency should be considered in the differential diagnosis and an urgent ammonia level determined. In case of hyperammonemia, the treatment should be started immediately , even without a precise ethiologic diagnosis.

A neonatal case of 3-hydroxy-3-methylglutaric-coenzyme A lyase deficiency

3-hydroxy-3-methylglutaric aciduria (OMIM 246450) is a rare autosomal recessive inborn of metabolism due to the deficiency of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) lyase, an enzyme involved both in the ketogenic pathway and leucine catabolism. Acute decompensations present with lethargy, cianosis, hypotonia, vomiting and metabolic acidosis with hypoketotic hypoglycemia. We report the case of a 3 days male with sudden hypoglycemic crisis initially misdiagnosed as a sepsis. HMG-CoA lyase deficiency was achieved through acyl-carnitines profile (showing a typical increasing of 3-hydroxy-isovaleryl and 3-methylgluraryl carnitines) and urinary organic acids analysis (disclosing elevation of 3-hydroxy-3-methylglutaric, 3-methyl-glutaconic, 3-methylglutaric and 3-hydroxyisovaleric acids). This case underlines the need of suspecting such inborn metabolic disorder in cases with hypoglycemia and metabolic acidosis. Acyl-carnitine and urinary organic acids profiles are essential to achieve a prompt diagnosis of treatable metabolic disorders in order to prevent their acute crisis with serious or even fatal consequences.

Treatment with botulinum toxin of octo-nonagerians with oesophageal achalasia: a two-year follow-up study

BACKGROUND

Treatment of oesophageal achalasia with intrasphincteric injections of botulinum toxin has proved to be a successful alternative treatment modality. However, little is known about its long-term effects in very old patients.

AIM

To evaluate the effects of such treatment in octo-nonagerians during a 2-year follow-up period.

PATIENTS AND METHODS

Thirty-three patients with idiopathic oesophageal achalasia (range 81-94 years) entered the study. After basal evaluation and screening procedures, 100 U of botulinum toxin was injected at the lower oesophageal sphincter, and the procedure was repeated 1 month later. Data were collected at baseline and were compared after 1 and 2 years following the procedure.

RESULTS

Seventy-eight per cent of patients were considered responders at 1 year and 54% were considered responders at 2 years. The weight gain at the end of the follow-up period was 2 (0-3) kg. No significant relationship was found between baseline lower oesophageal sphincter pressure and symptoms score after 1 and 2 years of follow-up; moreover, no major complications of botulinum toxin therapy were reported.

CONCLUSION

Treatment of very old achalasic patients with botulinum toxin is safe, effective and yields good quality of life in a substantial proportion of these subjects.

Endoscopic treatment of gastroesophageal reflux disease

Gastroesophageal reflux disease is a common chronic disorder which has a severe effect on the patient's quality of life. In view of the high cost of medical therapy and the limitations of surgery, a variety of endoscopic techniques have been developed for the treatment of this condition, and these have shown apparently encouraging results, at least in the short term. However, promising results have been obtained in only around two-thirds of patients over a short-term follow-up period of about 6 months. Moreover, several inconsistencies have emerged between the efficacy of this form of treatment in improving symptoms and quality of life and a lack of improvement of objective parameters, such as lower esophageal sphincter pressure and esophageal acid exposure. The authors strongly endorse the need for comprehensive evaluation of clinical evidence on this topic. After an extensive evaluation of existing literature, we suggest that controlled studies are urgently needed in order to clarify the potential of endoscopic therapy, either in terms of cost-effectiveness or in comparison with standard therapy. Meanwhile, with regard to current practice, the use of endoscopic treatment should be limited to clinical trials, which should incorporate the provision of comprehensive and unbiased information to study patients.

Segmental dilatation of the ileum presenting with acute intestinal bleeding

The authors report a case of acute intestinal bleeding caused by ulcerated segmental ileal dilatation occurring in a 5-month-old infant. The profuse emission of dark red blood per rectum caused acute anemia (Hb 5.3 g/dL). Because of absence of any other sign and symptom and normal plain x-ray, a bleeding Meckel's diverticulum was suspected. Laparoscopy was performed showing the ileal dilatation, and through an enlarged port incision the bowel was exteriorized and resected. Histology results showed an ulcer caused by heterotopic gastric mucosa. The etiopathogenesis and clinical manifestations of segmental intestinal dilatation are discussed.

Long-term follow-up of achalasia patients treated with botulinum toxin

AIMS

To evaluate long-term efficacy of intrasphincteric injection of botulinum toxin in untreated achalasia patients; to analyse whether age can be a predictor of response; and to verify whether any objective measurements correlate with symptom relief

MATERIALS AND METHODS

A total of 37 patients (mean age 61.4+/-17.5 years) were enrolled, all of whom injected endoscopically with 100 U of botulinum toxin. Symptom score, oesophageal manometry and oesophageal radionuclide emptying were assessed prior to treatment and 4 weeks, 3 months and 1 year after botulinum toxin. In the case of failure or relapse (symptom score >2), treatment was repeated.

RESULTS

All but 6 patients (83.7%) were in clinical remission one month after botulinum toxin. At 12 months, mean symptom score was 0.9+/-0.5 (p<0.05 vs basal); mean lower oesophageal sphincter pressure was 22.0+/-6.3 (p<0.05 vs basal), and 10-min radionuclide retention was 14.0%+/-7.2 (p<0.05 vs basal). Of the 35 patients followed, 12 (34.3%) had a relapse and were re-treated; 4 out of 12 did not respond after re-treatment. Efficacy of first injection of botulinum toxin lasted for a mean period of 15.6 months (range 2-30). Up to day 31 (83.7%) patients were still in remission. We observed a trend towards a better response to botulinum toxin treatment in patients over 50 years (p=0.053). Moreover no correlation was found between any objective achalasia measurements and symptom relief (r coefficient between 0.1 and 0.5)

CONCLUSIONS

Results show that: 1) one or two intrasphincteric injections of botulinum toxin result in clinical and objective improvement in about 84% of achalasia patients and are not associated with serious side-effects; 2) patients over 50 years showed better benefit than younger patients; 3) no correlation was found between any objective measurements and symptom relief.

Antibody response to Helicobacter pylori CagA and heat-shock proteins in determining the risk of gastric cancer development

OBJECTIVE

To investigate whether the systemic antibody response to Helicobacter pylori heat shock protein B can be considered, in addition to anti cytotoxin-associated protein [CagA) antibody determination, a further serological marker of increased risk of gastric cancer development.

METHODS

A total of 98 Giemsa positive Helicobacter pylori patients (28 with gastric cancer, 30 with duodenal ulcer and 40 with nonulcer dyspepsia) were studied. Serum samples obtained from all patients were tested for IgG antibodies to CagA (116 kDa), VacA [89kDa) and heat skock protein B (54 kDa) antigens of Helicobacter pylori by the Western blot technique.

RESULTS

26/28 patients [(92.9% with gastric carcinoma, 29/30 patients [96.7%) with duodenal ulcer and 30/40 patients (75.0%) with non-ulcer dyspepsia were seropositive for CagA protein. The prevalence of serum IgG antibody to CagA in the cancer patients was not significantly higher than in duodenal ulcer and non-ulcer dyspepsia patients. The prevalence of antibodies to VacA was not significantly different between gastric carcinoma and non-ulcer dyspepsia patients. In contrast the prevalence of systemic antibodies to heat skock protein B was significantly higher in gastric cancer patients (78.6%) than in duodenal ulcer (36.7%, p=0.002) or nonulcer dyspepsia patients (52.5%, p=0.029).

CONCLUSIONS

The detection of antibodies to heat shock protein B is proposed as an additional test which, in association with the determination of serum antibodies to CagA, could help in determining the risk of developing severe gastroduodenal disease, and gastric cancer, in particular.

Long-term follow-up of achalasic patients treated with botulinum toxin

Botulinum toxin A (BoTx), a potent inhibitor of acetylcholine release from nerve endings both within the myenteric plexus and at the nerve-muscle junction, has been shown to decrease the lower esophageal sphincter (LES) pressure in patients with achalasia. Because of this property, the esophageal injection of BoTx has been suggested as an alternative treatment in achalasia. The objective of this study was to determine the long-term efficacy and safety of intrasphincteric injection of BoTx in a group of achalasic patients. Nineteen patients (mean age 56.1 +/- 19.2 years) were enrolled in the study. All of them were injected endoscopically with 100 U of BoTx by sclerotherapy needle at different sites of the LES. Symptom score (dysphagia, regurgitation and chest pain, each on a 0-3 scale), esophageal manometer and esophageal radionuclide emptying were assessed before the treatment and at 4 weeks, 3 months and 1 year after BoTx injection. In case of failure or relapse (symptom score > 2), the treatment was repeated. All but five patients (74%) were in clinical remission at 1 month. Mean symptom score after 1 month of BoTx decreased from 7.1 +/- 0.9 to 2.2 +/- 2.5 (p < 0.05). LES pressure decreased from 38.4 +/- 13.7 to 27.4 +/- 13.5 mmHg (p < 0.05) and 10-min radionuclide retention decreased from 70.9 +/- 20.7% to 33.8 +/- 27.0% (p < 0.05). Side-effects (transient chest pain) were mild and infrequent. At 12 months, the clinical score was 0.9 +/- 0.5 (p < 0.05 vs. basal); mean LES pressure was 22.0 +/- 7.1 (p < 0.05 vs. basal) and 10-min radionuclide retention was 15.8 +/- 6.0% (p < 0.05 vs. basal). The efficacy of the first injection of BoTx lasted for a mean period of 9 months (range 2-14 months). At the time of writing (follow-up period mean 17.6 months, range 2-31), 14 patients (10 with one injection) were still in remission (74%). Our results showed that one or two intrasphincteric injections of BoTx resulted in clinical and objective improvement in about 74% of achalasic patients and are not associated with serious adverse effects; the efficacy of BoTx treatment was long lasting; this procedure could be considered an attractive treatment, especially in elderly patients who are poor candidates for more invasive procedures.

A multicentre randomised study of intrasphincteric botulinum toxin in patients with oesophageal achalasia. GISMAD Achalasia Study Group

BACKGROUND

Intrasphincteric injection of botulinum toxin (Botx) has been proposed as treatment for oesophageal achalasia. However, the predictors of response and optimal dose remain unclear.

AIMS

To compare the effect of different doses of Botx and to identify predictors of response.

PATIENTS/METHODS

A total of 118 achalasic patients were randomised to receive one of three doses of Botx in a single injection: 50 U (n=40), 100 U (n=38), and 200 U (n=40). Of those who received 100 U, responsive patients were reinjected with an identical dose after 30 days. Clinical and manometric assessments were performed at baseline, 30 days after the initial injection of botulinum toxin, and at the end of follow up (mean 12 months; range 7-24 months).

RESULTS

Thirty days after the initial injection, 82% of patients were considered responders without a clear dose related effect. At the end of follow up however, relapse of symptoms was evident in 19% of patients who received two injections of 100 U compared with 47% and 43% in the 50 U and 200 U groups, respectively. Using Kaplan-Meier analysis, patients in the 100x2 U group were more likely to remain in remission at any time (p<0.04), with 68% (95% CI 59-83) still in remission at 24 months. In a multiple adjusted model, response to Botx was independently predicted by the occurrence of vigorous achalasia (odds ratio 3.3) and the 100x2 U regimen (odds ratio 3.2).

CONCLUSIONS

Two injections of 100 U of Botx 30 days apart appeared to be the most effective therapeutic schedule. The presence of vigorous achalasia was the principal determinant of the response to Botx.

Characterization of acid and alkaline reflux in patients with Barrett's esophagus. G.O.S.P.E. Operative Group for the study of Esophageal Precancer

Although the pathogenic role of gastroesophageal reflux in Barrett's esophagus is widely accepted, the pattern of gastric and esophageal pH profile of patients with Barrett's esophagus is not well documented. Moreover, the observation that a columnar-lined esophagus can also develop after gastrectomy implies that chronic irritation of the lower esophagus by duodenal juice can be as harmful as acid reflux. To test this hypothesis, we simultaneously monitored gastric and esophageal pH in 19 patients with endoscopically and histologically proven Barrett's esophagus, in 35 with slight-to-moderate esophagitis and in 10 healthy subjects. The gastroesophageal reflux pattern in both Barrett's esophagus and esophagitis was characterized by mainly acid refluxes. Esophageal acid exposure (% time pH < 4) was 39.4 in patients with Barrett's esophagus, 14.6 in patients with esophagitis (P < 0.05), and 3.1 in healthy subjects (P < 0.05). Seven of 19 patients with Barrett's esophagus and 7 of 35 with esophagitis had evidence of alkaline reflux too; but pure alkaline refluxes accounted for only 1.9% of total time in Barrett's esophagus and 0.3% in esophagitis patients. In conclusion, these results confirm the high prevalence and severity of acid reflux in patients with Barrett's esophagus and show that the reflux of pure alkaline material into the esophagus is a rare event in both Barrett's esophagus and esophagitis patients.

Primary mucinous carcinoma of the skin. Report of case

The authors report a case of a primary mucinous carcinoma of the skin. This is a rare adnexial tumor arising from the eccrine secretory coils. The histologic characteristic finding of this lesion is the heap of abundant mucinous material (sialomucin) in the dermis in which rare epithelial islands are free-floating. In this study we also value the importance of a correct diagnosis for an appropriate therapy.

Calcium antagonist antihypertensive treatment of non-insulin-dependent diabetics: efficacy and safety of lacidipine versus nifedipine SR

Arterial hypertension is a chronic condition regarded as one of the main risk factors for development of coronary atherosclerosis. As dyslipidemia and reduced glucose tolerance are also risk factors for coronary disease, it is considered important to use antihypertensive drugs having no negative effects on lipid and glucose metabolism when diabetic patients are treated for hypertension. Lacidipine, a new dihydropyridine-like calcium antagonist, has been shown in in vivo and in vitro preclinical studies to possess potent, long-lasting antihypertensive activity. The present study compared the efficacy and safety of once-daily treatment with lacidipine versus nifedipine SR given twice-daily in non-insulin-dependent diabetic patients. Results have shown a similar efficacy of the two treatments: 6 months later, both drugs had reduced blood pressure values [lacidipine from 184.8/105.2 mm Hg to 144.4/87.1 mm Hg; nifedipine slow-release (SR) from 182.3/106.8 mm Hg to 143.6/89.4 mmHg]. However, lacidipine exhibited a lower incidence of adverse events (particularly ankle edema and tachycardia) than nifedipine SR. Finally, both treatments showed no negative effect on metabolic parameters (total cholesterol, high-density lipoprotein cholesterol, triglycerides, and blood glucose).

An ultrasonographic method to measure the sensitivity of the baroreflex in clinical practice: application to pharmacological studies

To determine whether it is possible to assess baroreceptor sensitivity by measuring changes in blood velocity in the carotid artery and changes in the heart rate, we performed a series of 108 experiments in 19 hypertensives aged 20-57 years (mean 46.6 +/- 8.6). In each experiment, we took simultaneous measurements of carotid artery blood flow velocity (Doppler technique), the brachial intra-arterial blood pressure and the heart rate, during a rapid and transient increase in blood pressure induced by injections of phenylephrine. We then calculated the maximum slope of the regression lines correlating blood velocity with the heart period (Trieste method) and blood pressure with the heart period (Oxford method). We obtained good accuracy from the Trieste method compared with the Oxford method, as assessed by the mean of the sum of the squares (difference + 5%, NS). After the administration of 4 mg oral lacidipine to 13 essential hypertensives, aged 37-54 years (47.6 +/- 5.3), baroreflex sensitivity was not changed, as assessed by either method (Oxford method 10.1 +/- 5.5 versus 9.8 +/- 6.2 ms/mmHg; Trieste method - 0.57 +/- 0.32 versus - 0.49 +/- 0.31 ms/Hz). The coefficients of variation for the two methods, calculated for the measurements taken before and after the administration of lacidipine, were not statistically different (Oxford method 25.0 +/- 18.4 versus 36.2 +/- 16.0; Trieste method 36.7 +/- 19.2 versus 39.7 +/- 19.2). The new non-invasive Trieste method thus showed the same accuracy and precision as the invasive Oxford method in measuring baroreflex sensitivity and can be used in pharmacological studies.

[Comparative evaluation of 2 antiplaque mouthwashes containing chlorhexidine and sanguinarine]

The results obtained in a short-term longitudinal study suggest that sanguinarine mouthrinses are less effective in plaque control than those containing chlorhexidine. It is concluded that the real clinical effectiveness of sanguinarine mouthrinses has to be further studied in clinical trials.

[The sign of induced bleeding in the evaluation of individual susceptibility to periodontal disease. Experimental study in diabetic and non-diabetic patients]

The most recent hypotheses on the pathogenesis of periodontal disease have underlined the great importance exerted by individual susceptibility to the disease. The ability of a high ratio between bleeding index and plaque index as a way of identifying subjects at risk has been investigated, the values of this ratio being compared in a group of diabetic patients and in a group of non-diabetics with periodontal lesions of similar extent. The results obtained confirmed those of other Authors, testifying to the good capability of the bleeding/plaque ratio to identify patients with a high risk of developing advanced forms of periodontal disease.