Increased incidence of Campylobacter jejuni-associated Guillain-Barré syndromes in the Greater Paris area.

The role of Campylobacter jejuni as the triggering agent of Guillain-Barré syndrome (GBS) has not been reassessed since the end of the 1990s in France. We report that the number of C. jejuni-related GBS cases increased continuously between 1996 and 2007 in the Paris region (mean annual increment: 7%, P = 0·007).

Tongue weakness is associated with respiratory failure in patients with severe Guillain-Barré syndrome.

OBJECTIVE: Swallowing impairment may worsen respiratory weakness and conduct to respiratory complications such as aspiration pneumonia in Guillain-Barré syndrome (GBS). We prospectively evaluate how tongue weakness could be associated to bulbar dysfunction and respiratory weakness in severe GBS patients. MEASUREMENTS AND MAIN RESULTS: Tongue strength, dysphagia and respiratory parameters were measured in 16 GBS patients at intensive care unit (ICU) admission and discharge and in seven controls. Tongue strength was decreased in the GBS patients compared with the controls. At admission, patients with dysphagia and those requiring mechanical ventilation (MV) had greater tongue weakness. All the patients with initial tongue strength <150 g required MV during ICU stay. Tongue strength correlated significantly with respiratory parameters. CONCLUSION: This study confirms the strong association between bulbar and respiratory dysfunction in GBS admitted to ICU. Tongue weakness may be present in GBS, especially during the phase of increasing paralysis, and resolves during the recovery phase. Tongue strength and indices of global and respiratory strength vary in parallel throughout the course of GBS. Further studies are needed to assess if, when used in combination with other respiratory tests, tongue strength measurement could contribute to identify patients at high risk for respiratory complications.

Measuring inspiratory muscle strength in neuromuscular disease: one test or two?

Inspiratory muscle strength monitoring is crucial in patients with neuromuscular disorders. The sniff nasal inspiratory pressure (SNIP) and maximal inspiratory pressure (P(I,max)) are usually measured. The present study investigated whether the test yielding the best value at baseline continued to yield the best value during follow-up. The present study included 25 patients with Duchenne muscular dystrophy (DMD) and 61 with myotonic muscular dystrophy (MMD). SNIP and P(I,max) were measured at baseline and then annually. At baseline, SNIP was lower than P(I,max) in 20 (80%) DMD patients and 32 (52%) MMD patients. During follow-up in DMD patients, changes in the best method always occurred from SNIP to P(I,max). In MMD patients, when SNIP was better than P(I,max) at baseline, SNIP was usually (88%) better during follow-up, whereas a better P(I,max) than SNIP at baseline was frequently (50%) followed by a shift to SNIP. Maximal inspiratory pressure may be sufficient for monitoring inspiratory muscle function in Duchenne muscular dystrophy adults. In myotonic muscular dystrophy, the marked variability in the test yielding the best value at baseline indicates a need for performance of both tests at baseline. However, when sniff nasal inspiratory pressure measurement yields the best value at baseline, using sniff nasal inspiratory pressure alone during follow-up may be appropriate.

Nocturnal mechanical ventilation for chronic hypoventilation in patients with neuromuscular and chest wall disorders.

BACKGROUND: Chronic alveolar hypoventilation is a common complication of many neuromuscular and chest wall disorders. Long-term nocturnal mechanical ventilation is increasingly used to treat it. OBJECTIVES: To examine the efficacy of nocturnal mechanical ventilation in relieving hypoventilation related symptoms and in prolonging survival in people with neuromuscular or chest wall disorders. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Trials Register, MEDLINE (from January 1966 to June 2006), and EMBASE (from January 1980 to June 2006) for randomised trials and contacted authors of trials and other experts in the field. SELECTION CRITERIA: We searched for quasi-randomised or randomised controlled trials of participants with neuromuscular or chest wall disorder-related stable chronic hypoventilation of all ages and all degrees of severity, receiving any type and any mode of nocturnal mechanical ventilation. The primary outcome measure was short-term and long-term reversal of hypoventilation related clinical symptoms and secondary outcomes were unplanned hospital admission, one year mortality, short-term and long-term reversal of daytime hypercapnia, improvement of lung function and sleep breathing disorders. DATA COLLECTION AND ANALYSIS: We identified eight randomised trials. MAIN RESULTS: The eight eligible trials included a total of 144 participants. The relative risk of 'no improvement of hypoventilation related clinical symptoms' in the short-term following nocturnal mechanical ventilation was available in only one trial with 10 participants and was not significant, 0.09 (95% confidence interval (CI) 0.01 to 1.31). The relative risk of 'no reversal of daytime hypercapnia' in the short-term following nocturnal ventilation was significant and favoured treatment, 0.37 (95% CI 0.20 to 0.65). The weighted mean difference of nocturnal mean oxygen saturation was 5.45% (95% CI 1.47 to 9.44) more improvement in participants treated with nocturnal mechanical ventilation. For most of the outcome measures there was no significant long-term difference between nocturnal mechanical ventilation and no ventilation. However, the estimated risk of death based on three studies was reduced following nocturnal ventilation, 0.62 (95% CI 0.42 to 0.91). There was considerable and significant heterogeneity between the trials possibly related to differences between the study populations. Most of the secondary outcomes were not assessed in the eligible trials. Data from two crossover trials suggested no evidence for a difference in reversal of daytime hypercapnia and sleep study parameters between volume-cycled and pressure-cycled ventilation. No data could be summarised for the comparisons between invasive and non-invasive mechanical ventilation or between intermittent positive pressure and negative pressure ventilation. AUTHORS' CONCLUSIONS: Current evidence about the therapeutic benefit of mechanical ventilation is weak, but consistent, suggesting alleviation of the symptoms of chronic hypoventilation in the short-term. In three small studies survival was prolonged mainly in participants with motor neuron diseases. With the exception of motor neuron disease, further larger randomised trials are needed to confirm long-term beneficial effects of nocturnal mechanical ventilation on quality of life, morbidity and mortality, to assess its cost-benefit ratio in neuromuscular and chest wall diseases and to compare the different types and modes of ventilation.

[Campylobacter jejuni and cytomegalovirus (CMV) infections in patients with the Guillain-Barre syndrome]. / Infections à Campylobacter jejuni et à cytomégalovirus (CMV) associées au syndrome de Guillain-Barré (SGB).

Guillain-Barre syndrome (GBS) is a rare disease triggered by postinfectious mechanisms. The disease concerns all ages, and is widely distributed around the world. The principal risks are respiratory failure, especially during the initial phase of the disease, and persisting deficit at long term. Among the infectious known agents, Campylobacter jejuni and CMV represent more than 40% of GBS causes. The clinical presentation, and the long-term prognosis of GBS related to these two etiologies are different. The physiopathological mechanisms of the nervous attack are probably also different. There is no proof, at this time, that anti-infectious treatment can improve the prognosis. The treatment is based on the early use of immunomodulatory treatments like intravenous immunoglobulins or plasma exchanges.

Characteristics of tracheostomy phonation valves.

Phonation valves are commonly used devices that allow the restoration of speech in tracheostomised patients. However, their use should not compromise the physiological benefit of tracheostomy. Six commercialised phonation valves were studied in a dynamic set-up simulating a respiratory frequency of 20 breaths.min(-1), a tidal volume of 0.5 L and a peak flow rate of 0.5 L.s(-1). Resistance and additional work of breathing (WOB) were calculated. In 10 tracheostomised patients, evaluations using no phonation valve (baseline), and the most and one of the least resistive valves were carried out. Respiratory patterns and gas exchanges were recorded. Inspiratory difficulty was evaluated using the modified Borg scale. Valves displayed a wide array of resistance ranging 1.3-5.9 cmH2O.L(-1).s(-1). Additional WOB varied with a ratio of 4.4 between the best and the worst valve. While the different clinical conditions did not modify respiratory patterns and gas exchanges, a significant effect on the Borg scale rating was observed using ANOVA and post hoc analysis of baseline versus worst valve and one of the best valves versus worst valve. In conclusion, the variety of aerodynamic characteristics of phonation valves should be considered when choosing the device, according to the underlying condition of the patients benefiting from their use.

Sniff nasal inspiratory pressure: what is the optimal number of sniffs?

Sniff nasal inspiratory pressure (SNIP) measurement is a volitional noninvasive assessment of inspiratory muscle strength. A maximum of 10 sniffs is generally used. The purpose of the present study was to investigate whether the maximum SNIP improved after the tenth sniff. In total, 20 healthy volunteers and 305 patients with various neuromuscular and lung diseases were encouraged to perform 40 and 20 sniffs, respectively. The best SNIP among the first 10 sniffs was lower than the best SNIP among the next 10 sniffs in the healthy volunteers and patients. The SNIP improvement after the twentieth sniff was marginal. In conclusion, a learning effect persists after the tenth sniff. The current authors suggest using 10 additional sniffs when the best result of the first 10 sniffs is slightly below normal, or when sniff nasal inspiratory pressure is used to monitor a progressive decline in inspiratory muscle strength.

Intravenous immunoglobulin for Guillain-Barré syndrome.

BACKGROUND: Guillain-Barré syndrome is an acute, paralysing, inflammatory peripheral nerve disease. Intravenous immunoglobulin is beneficial in other autoimmune diseases. OBJECTIVES: We aimed to determine the efficacy of intravenous immunoglobulin for treating Guillain-Barré syndrome. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Trials Register (March 2005), MEDLINE (January 1966 to March 2005) and EMBASE (January 1980 to March 2005) using the terms 'Guillain-Barré syndrome' and 'acute polyradiculoneuritis'. SELECTION CRITERIA: We included all randomised and quasi-randomised trials. DATA COLLECTION AND ANALYSIS: Two authors independently selected papers, extracted data and assessed quality. MAIN RESULTS: Another Cochrane systematic review has shown that plasma exchange significantly hastens recovery. We found six randomised trials comparing intravenous immunoglobulin with plasma exchange. We undertook a meta-analysis of five trials involving 536, mostly adult participants who were unable to walk unaided and had been ill for less than two weeks. Our primary outcome measure was the change in a seven-grade disability scale four weeks after randomisation. The weighted mean difference of this measure was not statistically significant, being only -0.02 (95% confidence interval -0.25 to 0.20) of a disability grade more improvement in the intravenous immunoglobulin than the plasma exchange group. There were no statistically significant differences in other measures. One trial involving 249 participants compared plasma exchange followed by intravenous immunoglobulin with plasma exchange alone. Another involving 37 participants compared immunoabsorption followed by intravenous immunoglobulin with immunoabsorption alone. Neither revealed significant extra benefit from intravenous immunoglobulin. One study with 39 participants showed a trend towards more improvement with high-dose compared with low-dose intravenous immunoglobulin. Another trial with 51 children found no significant difference in outcome when the standard dose was given over two days rather than five days. Three studies including a total of 75 participants suggested that in children intravenous immunoglobulin significantly hastens recovery compared with supportive care. AUTHORS' CONCLUSIONS: In adults, there are no adequate comparisons with placebo. Randomised trials in severe disease show that intravenous immunoglobulin started within two weeks from onset hastens recovery as much as plasma exchange, which is known to be more effective than supportive care. Treatment with intravenous immunoglobulin is significantly more likely to be completed than plasma exchange. Giving intravenous immunoglobulin after plasma exchange did not confer significant extra benefit. In children, intravenous immunoglobulin probably hastens recovery compared with supportive care alone. More research is needed in mild disease and in treatment starting more than two weeks after onset of the condition. Dose-ranging studies are also needed.

Respiratory insufficiency and limb muscle weakness in adults with Pompe's disease.

The objective of the present study was to prospectively evaluate relationships linking age, respiratory function and locomotor function in 29 outpatients with late-onset Pompe's disease and to retrospectively determine clinical outcomes. Using univariate regression analysis, vital capacity (VC) was weakly, but significantly, correlated to shoulder motility, Walton score and lower-limb Modified Medical Research Council score. Six patients were able to walk without a walking aid and with only the help of a handrail on the stairs (Walton score=3), although VC was <50%. No parameters were significantly correlated with age. As assessed retrospectively, VC and locomotion deteriorated over time in most patients. In contrast, among the 16 patients started on invasive or noninvasive ventilation with VC monitoring, eight had a VC increase at the first measurement time-point. The absence of correlation with age and the presence, in some patients, of severe respiratory insufficiency without severe limb girdle muscle weakness indicate that respiratory function should be monitored independently from the degree of peripheral muscle weakness. Mechanical ventilation and tracheostomy may improve vital capacity and should, therefore, be taken into account when evaluating treatments for the adult form of Pompe's disease.

Significance of phrenic nerve electrophysiological abnormalities in Guillain-Barré syndrome.

The authors investigated whether the amplitude and latency of diaphragm compound muscle action potential helped predict respiratory failure in Guillain-Barré syndrome. Both variables were significantly but weakly correlated with vital capacity (VC) and were similar in unventilated (n = 60) and ventilated (n = 10) patients. In ventilated patients, motor loss severity, progression, and VC reduction were significantly greater, and bulbar dysfunction was more common. Predicting respiratory failure must rely on clinical features and VC.

[Prevalence and characteristics of Guillain-Barré syndromes associated with Campylobacter jejuni and cytomegalovirus in greater Paris]. / Prévalence et caractéristiques des syndromes de Guillain-Barré associés à Campylobacter jejuni et au cytomégalovirus en région parisienne.

AIM OF THE STUDY: We aimed to study prevalence and features of Campylobacter jejuni and cytomegalovirus (CMV)-associated Guillain-Barré syndromes (GBS) in a French care unit. PATIENTS AND METHODS: We studied 264 patients with GBS admitted at Raymond Poincaré hospital (Garches) between 1996 and 2001. Clinical data were obtained prospectively. Sera were collected at patients entry and tested retrospectively for anti-C. jejuni, anti-CMV and antigangliosides GM1 et GM2 antibodies. RESULTS: GBS associated with a serological evidence for a recent C. jejuni infection were the more frequent (58/264, 22%); they affected predominantly men of mature years (mean age: 51.3 years; sex-ratio M/F: 1.76), mostly after a gastrointestinal illness (52%); they were often pure motor forms (57%), were severe (mechanical ventilation: 40%) and associated to an anti-GM1 IgG and/or IgM response (44%). GBS cases involving a primary CMV infection were less frequent (40/264, 15%), but were severe too (mechanical ventilation: 37.5%); they occurred preferentially in young women (mean age: 35.9 years; sex-ratio MF: 0.82), often after respiratory tract symptoms (28%) or an influenza-like syndrome (15%) and were frequently associated with sensory loss (73%) and with an anti-GM2 IgM response (47%). CONCLUSION: C. jejuni and CMV proved to be major triggering agents of GBS in France. They are associated with distinct presentations, which are both severe.

Resting energy expenditure in Duchenne patients using home mechanical ventilation.

Nutritional status is both important and difficult to assess in patients with Duchenne muscular dystrophy (DMD), particularly in those requiring mechanical ventilation (MV). The current authors evaluated body composition (bio-impedancemetry), resting energy expenditure (REE; indirect calorimetry) and energy intake in 20 adult patients with DMD using home MV (nocturnal: n = 13; continuous: n = 7) and 12 age-matched healthy controls. The patients were smaller in height than the controls and had a lower body weight. Most of the reduction in body mass index was accounted for by a reduction in fat free mass (FFM). REE (kJ) was significantly reduced in the patients (4559+/-853 kJ x 24 h(-1) versus 7407+/-1312 kJ x 24 h(-1)), but the difference disappeared after correction for FFM. REE and FFM were correlated in both the controls and patients, but less strongly in the latter, the lower strength of the association being due to the patients using continuous MV (REE and FFM uncorrelated). The food intake of the patients was 1.2+/-0.4 greater than their REE. This study shows that patients with advanced forms of Duchenne muscular dystrophy have balanced energy intakes and resting energy expenditure.

[Long term domiciliary mechanical ventilation in patients with neuromuscular disease (indications, establishment and follow up)]. / Ventilation mécanique a domicile et au long cours des patients neuromusculaires (indication, mise en place et surveillance).

UNLABELLED: Neuromuscular diseases represent a heterogeneous group of pathologies which common feature is the development of a restrictive ventilatory failure. BACKGROUND: Respiratory insufficiency of neuromuscular origin manifests itself by functional symptoms that must be carefully searched for in the history, such as headaches, sleep disorders, or dyspnoea of effort, sometimes very mild, or in severe cases associated with orthopnoea. Follow up should be multi-disciplinary. On the respiratory level regular measurement of blood gases, vital capacity, maximum inspiratory and expiratory pressures as well as sleep studies, will detect the criteria for mechanical ventilation (hypercarbia > 45 mm Hg, nocturnal desaturation < 88%, vital capacity < 60%, PImax < 60 cm H2O). STATE OF THE ART: The establishment of mechanical ventilation is a major decision for patients with neuromuscular disease because of the important physical, psychological, social and sometimes financial consequences. The patients and their family must be instructed precisely in order to obtain the best possible observation and compliance. The establishment requires a stay in hospital of several days to optimise the choice of ventilator, its settings, and connections. The link with the organisation managing the domiciliary ventilation is fundamental in ensuring follow up after discharge from hospital. Techniques of cough assistance must be taught to each neuromuscular patient requiring mechanical ventilation. CONCLUSION: Ventilation of neuromuscular patients requires careful evaluation of the indications and rigorous follow up by a multidisciplinary team with wide experience of this type of disease.

Intravenous immunoglobulin for Guillain-Barré syndrome.

BACKGROUND: Guillain-Barré syndrome is an acute, paralysing, inflammatory peripheral nerve disease. Intravenous immunoglobulin purified from donated blood is beneficial in other autoimmune diseases. OBJECTIVES: We aimed to determine the efficacy of intravenous immunoglobulin for treating Guillain-Barré syndrome. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group register (search updated 11 February 2003), MEDLINE and EMBASE (from January 2000 to February 2003) using Guillain-Barré syndrome and acute polyradiculoneuritis as the search terms. We also searched bibliographies of trials and made contact with their authors and other experts. SELECTION CRITERIA: We included all randomised and quasi-randomised trials. DATA COLLECTION AND ANALYSIS: Two reviewers examined the titles and abstracts of all the papers retrieved by the search, extracted the data and assessed the quality of the trials independently. MAIN RESULTS: Two trials comparing intravenous immunoglobulin with supportive treatment were inadequate to establish its value. Another Cochrane systematic review has shown that plasma exchange hastens recovery. We found six randomised trials that compared intravenous immunoglobulin with plasma exchange. In a meta-analysis of five trials involving 536, mostly adult, participants who were unable to walk unaided and had been ill for less than two weeks. The primary outcome measure in this review was the change in a seven grade disability scale four weeks after randomisation. The weighted mean difference of this measure was not statistically significant, being only 0.04 (95% CI -0.26 to 0.19) of a disability grade more improvement in the intravenous immunoglobulin group than the plasma exchange group. There were also no statistically significant differences in time to walk unaided, mortality, and proportion of participants unable to walk without aid after a year. One trial involving 249 participants compared plasma exchange followed by intravenous immunoglobulin with plasma exchange alone, and another involving 37 participants compared immunoabsorption followed by intravenous immunoglobulin with immunoabsorption alone. Neither revealed significant extra benefit from intravenous immunoglobulin. One study of only 39 participants showed a trend towards more improvement with high-dose compared with low-dose intravenous immunoglobulin. REVIEWER'S CONCLUSIONS: Although there are no adequate comparisons with placebo, intravenous immunoglobulin hastens recovery from Guillain-Barré syndrome as much as plasma exchange. Giving intravenous immunoglobulin after plasma exchange is not significantly better than plasma exchange alone. Randomised trials are needed to decide the effect of intravenous immunoglobulin in children, in adults with mild disease and in adults who start treatment after more than two weeks.

Limitations of sniff nasal pressure in patients with severe neuromuscular weakness.

BACKGROUND: Inspiratory muscle strength in patients with neuromuscular disorders can be assessed using sniff inspiratory nasal pressure (Pn(sn)) and maximum inspiratory mouth pressure (PI(max)). However, the relative merits of Pn(sn) against PI(max) are not known in patients with severe neuromuscular disease. OBJECTIVE: To investigate whether severity of disease modifies the relation between Pn(sn) and PI(max). METHODS: Vital capacity (VC), Pn(sn), and PI(max) were measured in 258 patients with neuromuscular disorders. RESULTS: Data were analysed from 241 patients, 17 being unable to perform PI(max) or Pn(sn) manoeuvres. The correlation between Pn(sn) and PI(max) was +0.94 (p<0.0001), with a mean (SD) difference between Pn(sn) and PI(max) of -4.8 (21.2) cm H(2)O (the limits of agreement were 37.6 and -47.2 cm H(2)O). VC (% predicted) was positively correlated with Pn(sn)/PI(max) (r = +0.86; p<0.0001), with a lower Pn(sn)/PI(max) value in patients with a VC <40% of predicted than in those with a VC >40% (0.80 (0.35) v 1.04 (0.41); p<0.0001). CONCLUSIONS: PI(max) is greater than Pn(sn) in patients with a severe restrictive ventilatory defect caused by neuromuscular disease. Pn(sn) may not accurately reflect inspiratory muscle strength in such patients and it is thus advisable to use both tests.

Electrophysiology to predict mechanical ventilation in Guillain-Barré syndrome.

To determine whether electrophysiological features predict endotracheal mechanical ventilation (ETMV) in Guillain-Barré syndrome (GBS). Non-ventilated GBS patients admitted to an ICU underwent standard electrophysiological testing. Endotracheal mechanical ventilation was decided by physicians who were unaware of electrophysiological results. Sixty consecutive patients underwent electrophysiological testing within 17 days of GBS onset; based on Hadden's criteria, 37 (62%) had primary demyelinating, 18 (30%) equivocal and five (8%) axonal disease. Time at electrophysiological testing and proportions of patients treated by plasma exchange and intravenous immunoglobulins were similar in the three groups, whereas primary demyelinating patients had worse results for disability grade and arm grade. The ETMV was required within 20 days of electrophysiological testing in 20 patients, 17 (46%) in the primary demyelinating group, three (17%) in equivocal group and none in the axonal group (P = 0.02). This prospective study suggests that electrophysiological demyelination may predict a need for ETMV in GBS.

Monocyte chemoattractant protein 1 and chemokine receptor CCR2 productions in Guillain-Barré syndrome and experimental autoimmune neuritis.

Infiltration of activated lymphocytes and monocytes is a key phenomenon in the pathogenesis of Guillain-Barré syndrome (GBS) and experimental autoimmune neuritis (EAN). To investigate the role of chemokines, we determined the blood and nerve tissue expression of monocyte chemoattractant protein 1 (MCP-1), a major chemoattractant of monocytes and activated lymphocytes, and its receptor CCR2 in GBS and EAN. MCP-1 circulating levels (ng/ml) in GBS were increased at the time of progression, peaked at the time of plateau and normalized with recovery. MCP-1 circulating levels were the highest in the most disabled patients. The number of circulating CCR2 positive cells was lower in patients with GBS than in healthy subjects (p<0.004). In GBS, MCP-1 expression was observed in epineurial and endoneurial vessels, on infiltrating cells, Schwann cells and in the endoneurial extracellular matrix. Some CCR2 positive cells were observed in nerve biopsies of GBS patients. In EAN, a slight positivity for MCP-1 was observed in the sciatic nerve. There was no circulating CCR2 positive cells. However, at the time of plateau, a conspicuous infiltration of CCR2 positive cells was observed in the sciatic nerve that was no longer observed at the time of recovery. These results suggest that MCP-1 and CCR2 may participate to the recruitment of circulating mononuclear cells in nerve tissue in EAN and GBS.