Posture analysis in predicting fall-related injuries during French Navy Special Forces selection course using machine learning: a proof-of-concept study

INTRODUCTION

Injuries induced by falls represent the main cause of failure in the French Navy Special Forces selection course. In the present study, we made the assumption that probing the posture might contribute to predicting the risk of fall-related injury at the individual level.

METHODS

Before the start of the selection course, the postural signals of 99 male soldiers were recorded using static posturography while they were instructed to maintain balance with their eyes closed. The event to be predicted was a fall-related injury during the selection course that resulted in the definitive termination of participation. Following a machine learning methodology, we designed an artificial neural network model to predict the risk of fall-related injury from the descriptors of postural signal.

RESULTS

The neural network model successfully predicted with 69.9% accuracy (95% CI 69.3-70.5) the occurrence of a fall-related injury event during the selection course from the selected descriptors of the posture. The area under the curve value was 0.731 (95% CI 0.725-0.738), the sensitivity was 56.8% (95% CI 55.2-58.4) and the specificity was 77.7% (95% CI 76.8-0.78.6).

CONCLUSION

If confirmed with a larger sample, these findings suggest that probing the posture using static posturography and machine learning-based analysis might contribute to inform risk assessment of fall-related injury during military training, and could ultimately lead to the development of novel programmes for personalised injury prevention in military population.

Cost-utility of oral methylprednisolone in the treatment of multiple sclerosis relapses: Results from the COPOUSEP trial

BACKGROUND

Studies have shown that oral high-dose methylprednisolone (MP) is non-inferior to intravenous MP in treating multiple sclerosis relapses in terms of effectiveness and tolerance. In order to assist with resource allocation and decision-making, its cost-effectiveness must also be assessed. Our objective was to evaluate the cost-utility of per os high-dose MP as well as the cost-savings associated with implementing the strategy.

METHODS

A cost-utility analysis at 28 days was carried out using data from the French COPOUSEP multicenter, double-blind randomized controlled non-inferiority trial and the statutory health insurance reimbursement database. Costs were calculated using a societal perspective, including both direct and indirect costs. An incremental cost-effectiveness ratio was calculated and bootstrapping methods assessed the uncertainty surrounding the results. An alternative scenario analysis in which MP was administered at home was also carried out. A budgetary impact analysis was carried at five years.

RESULTS

In the conditions of the trial (hospitalized patients), there was no significant difference in utilities and costs at 28 days. The incremental cost-effectiveness ratio was €15,360 per quality-adjusted life-year gained. If multiple sclerosis relapses were treated at home, oral MP would be more effective, less costly and associated with annual savings up to 25 million euros for the French healthcare system.

CONCLUSIONS

Oral MP is cost-effective in the treatment of multiple sclerosis relapses and associated with major savings.

Exercise testing-based algorithms to diagnose McArdle disease and MAD defects

OBJECTIVE

As exercise intolerance and exercise-induced myalgia are commonly encountered in metabolic myopathies, functional screening tests are commonly used during the diagnostic work-up. Our objective was to evaluate the accuracy of isometric handgrip test (IHT) and progressive cycle ergometer test (PCET) to identify McArdle disease and myoadenylate deaminase (MAD) deficiency and to propose diagnostic algorithms using exercise-induced lactate and ammonia variations.

METHODS

A prospective sample of 46 patients underwent an IHT and a PCET as part of their exercise-induced myalgia and intolerance evaluation. The two diagnostics tests were compared against the results of muscle biopsy and/or the presence of mutations in PYGM. A total of 6 patients had McArdle disease, 5 a complete MAD deficiency (MAD absent), 12 a partial MAD deficiency, and 23 patients had normal muscle biopsy and acylcarnitine profile (disease control).

RESULTS

The two functional tests could diagnose all McArdle patients with statistical significance, combining a low lactate variation (IHT: <1 mmol/L, AUC = 0.963, P < .0001; PCET: <1 mmol/L, AUC = 0.990, P < .0001) and a large ammonia variation (IHT: >100 μmol/L, AUC = 0.944, P = .0005; PCET: >20 μmol/L, AUC = 1). PCET was superior to IHT for MAD absent diagnosis, combining very low ammonia variation (<10 μmol/L, AUC = 0.910, P < .0001) and moderate lactate variation (>1 mmol/L).

CONCLUSIONS

PCET-based decision tree was more accurate than IHT, with respective generalized squared correlations of 0.796 vs 0.668. IHT and PCET are both interesting diagnostic tools to identify McArdle disease, whereas cycle ergometer exercise is more efficient to diagnose complete MAD deficiency.

[A subacute dementia: Inflammatory cerebral amyloid angiopathy]

We report a case of inflammatory cerebral amyloid angiopathy (CAA) that led to rapid cognitive decline, seizures, visual hallucinations, hyperproteinorrachia and right hemispheric leukopathy. Brain biopsy gave the diagnosis of CAA. Although no inflammatory infiltrate was found in the biopsy sample, corticosteroids led to a regression of the radiological lesions without significant clinical improvement. CAA is a rare disease, defined by lesions of classical cerebral amyloid angiopathy and perivascular infiltrates in contact with the affected vessels. In cases of rapidly progressive dementia associated with leukopathy, inflammatory amyloid angiopathy should be considered as cognitive disorders may improve after immunosuppressive therapy.

[Impact of headache among studied military population in Afghanistan deployed in the Kabul military field hospital]

INTRODUCTION

Headaches are a common reason for consultation with a prevalence of 30%. Few data exist for military personnel, including in situations of war operations. The main objective of this work was to measure the evolution of the impact of headache in such a context.

MATERIALS AND METHODS

Two hundred and one personnel deployed in the Kaïa military field hospital in Afghanistan were recruited. A questionnaire designed to recognize headaches, supported by two quality of life scales (MIDAS and HIT-6) and a stress questionnaire were filled out before departure and upon return from missions.

DISCUSSION

Sixty-three patients with headache were initially identified, of whom 52 remained symptomatic during the mission. The average total score of MIDAS before departure was 4 days and fell to 1.4 days upon return, with a mean measured change of 3.3 days. For HIT-6, the mean total score was 51.2 points initially and 51.9 points at the end of the mission with a mean change of-0.3 points. Nine patients without headache initially became symptomatic: MIDAS and HIT-6 were not affected.

CONCLUSION

Thus, the impact of headache in the particular context of presence in a theater of operations was low: improved MIDAS score and the lack of influence on the HIT-6 score are underlined.

[Systematic implementation of transthoracic echocardiography, transesophageal echocardiography and 24-hour Holter ECG for the detection of cardiac sources of embolism in patients with stroke or transient ischemic attack. A retrospective study of 220 patients]

INTRODUCTION

Embolism of cardiac origin accounts for around 20% of ischemic strokes. ECG and transthoracic echocardiography (TTE) are commonly obtained during the evaluation of patient of ischemic stroke but specific indications for the transesophageal (TEE) echocardiography and 24-hour Holter ECG (Holter) remain uncertain.

OBJECTIVES

The aim of this study is to report the contribution of TTE, TEE and Holter performed as a routine during the evaluation of patients with ischemic stroke (IS) or transient ischemic attack (TIA).

METHODS

This is a retrospective single-center study of 220 patients hospitalized between 1st January 2007 and 31st December 2010 for a first IS or TIA.

RESULTS

One hundred and forty-three IS and 77 TIA are identified. The average age of patients was 66 years (18-88 years). TTE/TEE/24-hour Holter allowed the diagnosis of cardiac sources of embolism in 135 patents (61.3%). TTE/TEE identified potential source of cardiogenic embolism in 126 patients (52.2%). Twenty four-hour Holter ECG tracked supraventricular arrhythmia in 15 patients (6.7%), 9 (4%) which had non-contributory ultrasound assessment.

CONCLUSION

The systematic implementation of TTE/TEE/Holter is useful for identifying potential sources of cardiogenic embolism. The performance of TEE remains above the TTE. Holter should be recommended because it is a cost effective and non-invasive tool.

[Exercise-induced muscle pain due to phosphofrutokinase deficiency: Diagnostic contribution of metabolic explorations (exercise tests, 31P-nuclear magnetic resonance spectroscopy)]

INTRODUCTION

Muscle phosphofructokinase deficiency, the seventh member of the glycogen storage diseases family, is also called Tarui's disease (GSD VII).

METHODS

We studied two patients in two unrelated families with Tarui's disease, analyzing clinical features, CK level, EMG, muscle biopsy findings and molecular genetics features. Metabolic muscle explorations (forearm ischemic exercise test [FIET]; bicycle ergometer exercise test [EE]; 31P-nuclear magnetic resonance spectroscopy of calf muscle [31P-NMR-S]) are performed as appropriate.

RESULTS

Two patients, a 47-year-old man and a 38-year-old woman, complained of exercise-induced fatigue since childhood. The neurological examination was normal or showed light weakness. Laboratory studies showed increased CPK, serum uric acid and reticulocyte count without anemia. There was no increase in the blood lactate level during the FIET or the EE although there was a light increase in the respiratory exchange ratio during the EE. 31P-NMR-S revealed no intracellular acidification or accumulated intermediates such as phosphorylated monoesters (PME) known to be pathognomic for GSD VII. Two new mutations were identified.

DISCUSSION

FIET and EE were non-contributive to diagnosis, but 31P-NMR provided a characteristic spectra of Tarui's disease, in agreement with phosphofructokinase activity level in erythrocytes. Muscle biopsy does not always provide useful information for diagnosis. In these two cases, genetic studies failed to establish a genotype-phenotype correlation.

CONCLUSION

The search for phosphofructokinase deficiency should be continued throughout life in adults experiencing fatigability or weakness because of the severe disability for daily life activities caused by the late onset form.

The French Pompe registry. Baseline characteristics of a cohort of 126 patients with adult Pompe disease

Pompe disease is a rare autosomal recessive muscle lysosomal glycogenosis, characterised by limb-girdle muscle weakness and frequent respiratory involvement. The French Pompe registry was created in 2004 with the initial aim of studying the natural history of French patients with adult Pompe disease. Since the marketing in 2006 of enzyme replacement therapy (alglucosidase alfa, Myozyme(®)), the French Pompe registry has also been used to prospectively gather the biological and clinical follow-up data of all adult patients currently treated in France. This report describes the main clinical and molecular features, at the time of inclusion in the French registry, of 126 patients followed up in 21 hospital-based neuromuscular or metabolic centres. Sixty-five men and 61 women have been included in the registry. Median age at inclusion was 49 years, and the median age at onset of progressive limb weakness was 35 years. Fifty-five percent of the patients were walking without assistance, 24% were using a stick or a walking frame, and 21% were using a wheelchair. Forty-six percent of the patients needed ventilatory assistance, which was non-invasive in 35% of the cases. When performed, muscle biopsies showed specific features of Pompe disease in less than two-thirds of the cases, confirming the importance of acid alpha-glucosidase enzymatic assessment to establish the diagnosis. Molecular analysis detected the common c.-32-13T>G mutation, in at least one allele, in 90% of patients. The French Pompe registry is so far the largest country-based prospective study of patients with Pompe disease, and further analysis will be performed to study the impact of enzyme replacement therapy on the progression of the disease.

[Dysautonomic syndrome of the face with Harlequin sign and syndrome: Three new cases and a review of the literature]

INTRODUCTION

Harlequin phenomenon is characterized by a strictly unilateral erythrosis of the face with flushing and hyperhydrosis, and controlaterally a pale anhydrotic aspect. This syndrome can occur alone or associated to other dysautonomic phenomena such as Horner syndrome, Adie syndrome or Ross syndrome.

PATIENTS AND METHODS

We report three cases: two patients presented a Harlequin sign, associated with Horner syndrome for one and Ross syndrome for the second. The etiologic investigation was normal, allowing recognizing the idiopathic nature of the disorder. For the third patient, Harlequin syndrome was observed in a neoplastic context due to breast cancer, metastatic dissemination, and bone metastases involving the right side of the T2 body.

DISCUSSION

We reviewed the literature: 108 cases have been described. This syndrome occurred alone in 48 patients and was associated with other dysautonomic syndromes such as Horner syndrome in 38 patients, Holmes Adie syndrome in six, and Ross syndrome in six; both Ross and Holmes Adie syndrome were associated five cases and associations were not reported in five patients. The pathophysiological mechanisms of this autonomic cranial neuropathy, the possible etiologies, and therapeutic management were discussed.

CONCLUSION

Harlequin phenomenon with flushing and unilateral hyperhydrosis is rare, occurring alone or in combination with other autonomic syndromes of the face. Idiopathic in two-thirds of cases, Harlequin phenomenon does not require specific treatment; sympathectomy may be discussed in the severe cases with a significant social impact.

[Miliary cerebral Histoplasma capsulatum in an HIV-negative patient]

A 58 year-old man who lived in Africa for 17 years, presented, four years after returning to western France, acute confusion and weight loss. He had no fever and no immunosuppression. Clinical examination revealed Babinski sign, mucosal ulcerations of the mouth and hepatomegaly. The lumbar puncture revealed a meningitis and MRI showed a few parenchymal enhancing masses in the brain. Stereotaxic biopsies were performed. Specific culture and coloration were positive for the diagnosis of cerebral histoplasmosis. At the beginning, antifungal treatment with amphotericin B and itraconazole provided improvement. But seizures occurred and the treatment by carbamazepine induced decreased blood level of itraconazole. Despite itraconazole IV the patient died. This observation illustrates the difficulties in diagnosis and treatment of cerebral histoplasmosis and the various patterns of drug interactions.

[Clinical, electrophysiological and MRI correlations in carpal tunnel syndrome]

Even though diagnosis of carpal tunnel syndrome is mainly based on clinical findings, other examinations are often useful for confirmation and management. The most useful of these examinations is EMG. However, EMG may be inconclusive and MRI may then be helpful. The indications for MRI in patients with carpal tunnel syndrome will be reviewed.

METHOD

20 patients with a total of 33 clinically suspected cases of carpal tunnel syndrome (CTS) underwent EMG and MRI evaluation. Clinical and EMG findings identified three groups of patients based on degree of deficit: mild, moderate, and severe. The following structures were evaluated at MRI: median nerve, retinaculum, retrotendinous fat, flexor tendons, thenar space, and muscles and bones of the wrist. Surgery was performed for 19 wrists.

RESULTS

Only retinacular bowing and increased T2W signal intensity within the median nerve were significantly related to the diagnosis of CTS (sensitivity of 70% and 57% respectively). Retinacular bowing indicates increased "pressure" within the compartment (mechanical compression of the nerve) and increased T2W signal of the median nerve indicates nerve suffering. These findings correlated well with more severe cases based on clinical and EMG findings.

CONCLUSION

In cases where there is discordance between clinical and EMG findings, MRI is helpful to identify patients who would benefit from surgical intervention.

[Suprascapular palsy: a complication of surgical positioning?]

We report a case of persisting suprascapular nerve palsy after surgery under general anaesthesia of short duration in a conventional position. Surgical exploration, eight months later, showed a suprascapular notch narrowed by a hypertrophied and calcified superior transverse ligament. Such a lesion and the practice of volley-ball by the patient are in favour of a pre-existing infraclinical neuropathy.

Idiopathic carpal tunnel syndrome. Clinical, electrodiagnostic, and magnetic resonance imaging correlations

BACKGROUND

Although carpal tunnel syndrome is diagnosed primarily on clinical grounds, a number of investigations can be helpful in confirming the diagnosis and providing therapeutic orientation. Electrodiagnostic testing is the most widely used method in everyday practice but can be inconclusive or inconsistent with the clinical findings. Magnetic resonance imaging is useful in such cases.

OBJECTIVES

To compare the diagnostic usefulness of electrodiagnostic testing and magnetic resonance imaging in patients with carpal tunnel syndrome.

PATIENTS AND METHODS

Thirty-three cases of clinically-defined carpal tunnel syndrome in 20 patients were investigated by electrodiagnostic testing and magnetic resonance imaging. The nerve entrapment was categorized as mild, moderate, or severe based on clinical and electrodiagnostic findings. Structures evaluated on magnetic resonance imaging scans were the median nerve, the flexor retinaculum, the flexor tendons, the fat lying deep to the tendons, the thenar compartment, and the carpal bones.

RESULTS

Bowing of the transverse carpal ligament, high signal from the median nerve on T2 images, and median nerve enlargement were found in 70%, 57%, and 55% of cases, respectively. Bowing of the transverse carpal ligament is a cause of mechanical compression, whereas the other two signs reflect injury to the median nerve. High signal from the median nerve was associated with more severe clinical and/or electrodiagnostic abnormalities.

CONCLUSION

When electrodiagnostic abnormalities suggest more severe disease than expected or are otherwise discordant with clinical findings, demonstration by magnetic resonance imaging of high median nerve signal and/or median nerve enlargement may help to select those patients most likely to benefit from surgical treatment.

[Hemichorea and striatal infarction]

We present two cases of hemichorea associated with an arterial ischaemic stroke in the controlateral striatum and we reviewed 28 similar cases in the literature. The pathogenesis of this movement disorder involves the gabaergic and enkephalinergic neurons of the striatal matrice which mainly projects on the external globus pallidus. A destruction of the striatal neurons of the indirect striato-thalamo-cortical ways may reduce their inhibitory out flow on normal inhibited thalamic and cortical structures and then create abnormal choreiform movements. The scarcity of this phenomenon can be explained by: 1) the repartition of the enkephalinergic local circuit neurons which represent but one third of the motor striatal neuronal population; 2) the type of vascularisation which often involves larger territories in the striatum and the globus pallidus or the anterior limb of the internal capsule. These abnormal movements are often transient because of the regulation of accessory striato-nigro-striatal, cortico-striato-nigro-thalamo-cortical and cortico-luysin circuits. More over, because these hypotheses and after having reviewed all such cases in literature, choreic movements to pure thalamic involvement are to be questioned.