Myasthénie du sujet âgé: diagnostic, comorbidité et évolution

Myasthenia gravis treatment in the elderly presents with a significant iatrogenic risk: a multicentric retrospective study

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disease treated with acetylcholinesterase inhibitors and immunosuppressant/immunomodulatory drugs. MG is frequently diagnosed in elderly patients, a fragile population in which treatment adverse effects (TAE) have not been evaluated until now.

METHODS

We retrospectively analysed the files of all MG patients with disease onset after age 70 years in four French University Hospitals, including clinical, electrophysiological, biological, and treatment data, with an emphasis on TAE. MG outcomes were assessed using the Myasthenia Gravis Foundation of America (MGFA) status scale.

RESULTS

We included 138 patients (59% of men) with a mean follow-up of 4.5 years (range 1-19). Mean age at diagnosis was 78 years (70-93). Anti-acetylcholine receptor antibodies were found in 87% of cases, electrophysiological abnormalities in 82%, and thymoma in 10%. MG outcome was good in a majority of cases, with 76% of treated patients presenting with alleviated symptoms at follow-up. TAE were observed in 41% of patients, including severe TAE in 14% of cases. Seven patients (5.1%) died, including four (2.9%) from MG-related respiratory failure, and three (2.2%) from MG treatment-related complications, i.e., sepsis in 2 cases and brain toxoplasmosis in 1 case. TAE were observed in 53% of patients treated with azathioprine, 23% of patients treated with corticosteroids, and 15% of patients treated with mycophenolate mofetil.

CONCLUSIONS

This retrospective study demonstrates MG in the elderly presents with a significant iatrogenic risk, including fatal immunosuppressant-related infections.

Myasthenic crisis treated in a Chinese neurological intensive care unit: clinical features, mortality, outcomes, and predictors of survival

BACKGROUND

Myasthenic crisis (MC) often requires admission to an intensive care unit (ICU).

METHODS

We retrospectively investigated 113 consecutive patients with first MC admitted to the neurological ICU. Patients' demographic, clinical and other characteristics were examined, as well as therapeutic interventions, mortality and functional outcome.

RESULTS

MC patients at first onset admitted to neurological ICU had a mortality rate of 18.6%. PCO₂ level before intubation and score on Myasthenia Gravis-Activities of Daily Living (MG-ADL) scale at MC onset correlated with duration of ventilation and length of ICU stay. Compared with patients with good functional outcome, patients with intermediate or poor functional outcome were older at first MC onset, had lower pH and PO₂, and had higher PCO₂ before intubation. Multivariate logistic analysis identified pre-intubation PCO₂ level as an independent predictor of survival. Cox regression showed that age at first MC onset requiring ICU management was the factor which significantly influenced the mortality.

CONCLUSIONS

Our results suggest that PCO₂ before intubation and MG-ADL score at MC onset may be useful indicators of more severe disease likely to require extensive respiratory support and ICU management. Higher pre-intubation PCO₂ indicates chronic respiratory acidosis that can increase risk of severe disability and death, especially in patients with older age at first MC onset.

Causes and surgical treatment of diplopia and strabismus secondary to myasthenia gravis

OBJECTIVE

To present a report of the ocular motility disorders, treatment and outcomes of myasthenia gravis (MG).

MATERIAL AND METHOD

A retrospective study was performed on the data of patients with MG. An evaluation was made using mean age, gender, initial diagnosis, ocular deviation, time of onset of clinical characteristics, treatment and results. Resolution of diplopia and/or ocular deviation in primary and reading gaze was considered a good outcome at the end of follow-up.

RESULTS

A total of 14 cases were included. The mean age of the sample was 55.64 years, of which 9 were women, and 10 cases were bilateral. The diagnosis was made by ophthalmologists in 4 cases. The initial diagnoses were diverse: bilateral cranial third nerve palsy in 3, unilateral third nerve palsy in 1, superior or inferior rectus palsy in 3, sixth nerve palsy in 2, fourth nerve palsy in 1, exotropia in 3 and esotropia in 1. Diplopia was presented in 14 cases and 9 associated ptosis. The different types of strabismus were horizontal ocular deviation in 11 cases: 8 with exotropia, and 4 with vertical deviation. Strabismus surgery was performed in 4 cases that did not respond to medical treatment, with a good final outcome. Pharmacological treatment resolved diplopia in 6 cases, and prisms in one. Ptosis surgery was only necessary in one patient. Outcome was favourable in 78.57% at the end of follow-up.

CONCLUSION

Acute onset diplopia caused by strabismus with variable angle or oculomotor palsy, associated or not with a ptosis can indicate MG. There were favourable outcomes with strabismus surgery. Pharmacological treatment did not resolve the diplopia in all cases.

Late-onset myasthenia gravis - CTLA4(low) genotype association and low-for-age thymic output of naïve T cells

Late-onset myasthenia gravis (LOMG) has become the largest MG subgroup, but the underlying pathogenetic mechanisms remain mysterious. Among the few etiological clues are the almost unique serologic parallels between LOMG and thymoma-associated MG (TAMG), notably autoantibodies against acetylcholine receptors, titin, ryanodine receptor, type I interferons or IL-12. This is why we checked LOMG patients for two further peculiar features of TAMG - its associations with the CTLA4(high/gain-of-function) +49A/A genotype and with increased thymic export of naïve T cells into the blood, possibly after defective negative selection in AIRE-deficient thymomas. We analyzed genomic DNA from 116 Caucasian LOMG patients for CTLA4 alleles by PCR/restriction fragment length polymorphism, and blood mononuclear cells for recent thymic emigrants by quantitative PCR for T cell receptor excision circles. In sharp contrast with TAMG, we now find that: i) CTLA4(low) +49G(+) genotypes were more frequent (p = 0.0029) among the 69 LOMG patients with age at onset ≥60 years compared with 172 healthy controls; ii) thymic export of naïve T cells from the non-neoplastic thymuses of 36 LOMG patients was lower (p = 0.0058) at diagnosis than in 77 age-matched controls. These new findings are important because they suggest distinct initiating mechanisms in TAMG and LOMG and hint at aberrant immuno-regulation in the periphery in LOMG. We therefore propose alternate defects in central thymic or peripheral tolerance induction in TAMG and LOMG converging on similar final outcomes. In addition, our data support a 60-year-threshold for onset of 'true LOMG' and an LOMG/early-onset MG overlapping group of patients between 40 and 60.

Thymus pathology observed in the MGTX trial

The MGTX trial is the first prospective, randomized clinical trial that aims to evaluate the impact of extended transsternal thymectomy on myasthenic symptoms, prednisone requirements, and quality of life in patients with nonthymomatous, anti-acetylcholine receptor autoantibody-positive myasthenia gravis (MG). Here, we give an overview of the rationale of thymectomy and the standardized macroscopic and histopathological work-up of thymectomy specimens as fixed in MGTX standard operating procedures, including the grading of thymic lymphofollicular hyperplasia and the morphometric strategy to assess thymic involution.

[Is myasthenia gravis overlooked in the over-80s? Two case reports]

Myasthenia gravis (MG) is diagnosed more often today than previously. The increase is mainly found in patients over the age of 60 years. Recent data indicate that MG may still be substantially underdiagnosed in very old people. We report two cases of MG in elderly women, in whom the initial diagnosis was uncertain. When faced with new onset of weakness in an elderly patient, particularly of cranial musculature, clinicians should consider MG as a diagnostic possibility.

Myasthenia gravis in the elderly: a rare cause of undernutrition

Myasthenia gravis is not a frequent disease in the elderly. The diagnosis of this neuromuscular junction disease in the elderly is difficult because of comorbidities and the broad differential diagnosis. We report here the case of a 86-year-old woman referred to hospital for loss of weight and difficulties in feeding. She was cachectic and had been suffering from dysphagia for several weeks. One week later, her clinical state worsened with the appearance of ptosis and oropharyngeal dysfunction, disturbing eating and talking. Myasthenia gravis was suspected and confirmed by a positive acetylcholine receptor antibody titer. The clinical state of the patient unfortunately worsened, with acute respiratory insufficiency, causing death. Myasthenia gravis must be suspected in a context of dysphagia, swallowing difficulties and loss of weight. This diagnosis leads to specific and symptomatic treatment and allows neuromuscular blockade-inducing drugs to be avoided.

[Small cell lung cancer]

With about 20% of all lung cancers small cell lung cancer (SCLC) represents a major subset of this entity. Although therapeutic improvements did not receive as much attention as in non small cell lung cancer (NSCLC), many small steps of clinical progress have been achieved within the last 20 years. An optimal treatment should be based on an interdisciplinary treatment plan. The standard treatment in localized stages represents combined radiation and chemotherapy. Cisplatin and etoposide are in this concern considered as a gold standard. 3D-planned conformal radiotherapy should start as early as possible and should be applied concomitantly to chemotherapy and in certain cases even in a hyperfractionated treatment protocol. In very early stages surgical resection could be an option in selected cases. In advanced stages a platinum-based doublet offers high response rates. As already established in limited disease prophylactic cranial irradiation is now also indicated in extensive disease in case of any tumor remission. In the second line treatment and in patients with reduced performance status topotecan is recommended. Similar as in NSCLC pemetrexed might become an alternative treatment option in the second line setting. In the field of new targeted therapies bevacizumab achieved the most promising results. The present review highlights historical milestones and up-to-date trends in radiotherapy, chemotherapy and surgery. Furthermore, the role of experimental strategies and the management of certain special clinical situations are discussed.