Kernel-based testing for single-cell differential analysis

Single-cell technologies offer insights into molecular feature distributions, but comparing them poses challenges. We propose a kernel-testing framework for non-linear cell-wise distribution comparison, analyzing gene expression and epigenomic modifications. Our method allows feature-wise and global transcriptome/epigenome comparisons, revealing cell population heterogeneities. Using a classifier based on embedding variability, we identify transitions in cell states, overcoming limitations of traditional single-cell analysis. Applied to single-cell ChIP-Seq data, our approach identifies untreated breast cancer cells with an epigenomic profile resembling persister cells. This demonstrates the effectiveness of kernel testing in uncovering subtle population variations that might be missed by other methods.

Abnormal gait pattern in downhill hiking is related to muscular deficits of the knee flexors and extensors in active patients with total knee arthroplasty

BACKGROUND

To assess the in-field walking mechanics during downhill hiking of patients with total knee arthroplasty five to 14 months after surgery and an age-matched healthy control group and relate them to the knee flexor and extensor muscle strength.

METHODS

Participants walked on a predetermined hiking trail at a self-selected, comfortable pace wearing an inertial sensor system for recording the whole-body 3D kinematics. Sagittal plane hip, knee, and ankle joint angles were evaluated over the gait cycle at level walking and two different negative slopes. The concentric and eccentric lower extremity muscle strength of the knee flexors and extensors isokinetically at 50 and 120°/s were measured.

FINDINGS

Less knee flexion angles during stance have been measured in patients in the operated limb compared to healthy controls in all conditions (level walking, moderate downhill, steep downhill). The differences increased with steepness. Muscle strength was lower in patients for both muscle groups and all measured conditions. The functional hamstrings to quadriceps ratio at 120°/sec correlated with knee angle during level and downhill walking at the moderate slope in patients, showing higher ratios with lower peak knee flexion angles.

INTERPRETATION

The study shows that even if rehabilitation has been completed successfully and complication-free, five to 14 months after surgery, the muscular condition was still insufficient to display a normal gait pattern during downhill hiking. The muscle balance between quadriceps and hamstring muscles seems related to the persistence of a stiff knee gait pattern after knee arthroplasty. LoE: III.

Influence of different CCD angles on osseointegration and radiological changes after total hip arthroplasty of a triple wedge shape cementless femoral stem: a prospective cohort study

PURPOSE

The purpose of this study was to evaluate the osseointegration and radiological outcomes in patients after total hip arthroplasty, hypothesizing different load patterns with one cementless stem design and different CCD angles (CLS Spotorno femoral stem 125° vs 135°).

METHODS

All cases of degenerative hip osteoarthritis fulfilling strict inclusion criteria were treated with cementless hip arthroplasty between 2008 and 2017. Ninety-two out of one hundred six cases were clinically and radiologically examined three and 12 months after implantation. Two groups with each 46 patients were rendered prospectively and compared in clinical (Harris Hip Score) and radiological outcome.

RESULTS

At final follow-up, no significant difference regarding Harris Hip Score was detected between the two groups (mean 99.2 ± 3.7 vs. 99.3 ± 2.5; p = 0.73). Cortical hypertrophy was found in none of the patients. Stress shielding was seen in a total of 52 hips (n = 27 vs. n = 25; 57% of the 92 hips). No significant difference regarding stress shielding was detected when comparing both groups (p = 0.67). Significant bone density loss was detected in Gruen zone one and two in the 125° group. The 135° group showed significant radiolucency in Gruen zone seven. No overall radiological loosening or subsidence of the femoral component was observed.

CONCLUSION

According to our results, the use of a femoral component with a 125° CCD angle versus a 135° CCD did not result in a different osseointegration and load transfer with a clinically relevant significance.

Impact of keel saw blade design and thickness on the incidence of tibial plateau fracture and tibial implant-loosening in cementless medial UKR

BACKGROUND

Tibial plateau fractures and tibial implant- loosening are severe complications in cementless unicompartmental knee replacement (UKR). The tibial keel preparation is particularly demanding and different saw blades can be used. It was hypothesized that different blade designs and thickness have an influence on the frequency of tibial plateau fractures and implant-loosening in cementless medial UKR.

METHODS

1258 patients with cementless medial UKR were included in this retrospective study between 2013 and 2020. The tibial keel cut was performed either with a double keel saw blade (DKS; 2.8 mm) and added hand guided pick or a mono reciprocating saw blade (RKB) of different thickness (2.5 mm; 2.65 mm; 2.75 mm). Tibial plateau fracture and loosening were demonstrated by standard two-plane radiographs. Tibial implant-loosening was defined as complete radiolucency and implant migration. Fracture and loosening were combined with pain and loss of function.

RESULTS

In 126 patients (10%) the tibial keel was prepared with DKS, in 407 patients (32.4%) with RKB 2.5 mm, in 330 patients (26.2%) with RKB 2.65 mm and in 395 patients (31.4%) with 2.75 mm. In 4 patients (3.17%) with DKS tibial plateau fracture occurred, in 4 patients (0.99%) with 2.5 mm RKB, in 3 patients (0.92%) with 2.65 mm RKB and in 1 patient (0.25%) with 2.75 mm RKB. Significantly fewer fractures occurred with a RKB design (p = 0.007). A negative correlation between fracture incidence and RKB saw blade thickness was found (Spearman-r = - 0.93). No difference for tibial implant-loosening was shown (p = 0.51).

CONCLUSION

Different blade designs and thickness have a significant influence on the incidence of tibial plateau fractures and aseptic tibial implant-loosening. The incidence of tibial plateau fractures in cementless medial UKR can be reduced by changing the design and thickness of the tibial keel saw blade. Greater thickness of RKB leads to significantly fewer tibial plateau fractures while the incidence of implant-loosening is not increasing.

TRIAL REGISTRATION

This study was retrospectively registered and ethical approval was waived by the local ethical committee (No. 2020-1174).

[Anticholinergic scales: Use in psychiatry and update of the anticholinergic impregnation scale]

Anticholinergic properties are well known to prescribers, notably in mental health, as a therapeutic strategy for i.e. extrapyramidal syndrome but also as a source of numerous adverse side effects. Herein, we propose a narrative literature review describing: (i) cholinergic pharmacology and anticholinergic properties; (ii) the importance of anticholinergic therapeutic properties in psychiatry; (iii) the existing anticholinergic drug scales and their usage limitations in Psychiatry and; last (iv) an update to the anticholinergic drug impregnation scale, designed for the French psychiatry practice. The anticholinergic side effects can appear both in the peripheral level (dry mouth, constipation, etc.) and in the central level (especially as cognitive deficits). Many of the so called « anticholinergic » drugs are in fact entirely or mostly antimuscarinic and act essentially as parasympathetic system antagonists. Overall, anticholinergic/antimuscarinic side effects are usually attributed to psychotropic medications: to certain antipsychotics, notably classical neuroleptics such as phenothiazine and also to tricyclic antidepressants. In practice, the impact of anticholinergic toxicity treatments is often highlighted due to their excessively prolonged use in patients on antipsychotics. Interestingly, these antipsychotic treatments are better known for their anticholinergic side effects, especially cognitive ones, with an early onset specially in elder patients and/or in the case of polymedication. In order to evaluate anticholinergic side effects, metrics known as anticholinergic burden scales were created in the last few decades. Nowadays, 13 different scales are documented and accepted by the international academic community, but only three of them are commonly used: the Anticholinergic Drug Scale (ADS), the Anticholinergic Risk Scale (ARS) and the Anticholinergic Burden Scale (ACB). All of them are based on a similar principle, consisting of grading treatments individually, and they are normally scored from 0 - no presence of side effects - to 3 - anticholinergic effects considered to be strong or very strong. Using these scales enables the calculation of the so-called "anticholinergic burden", which corresponds to the cumulative effect of using multiple medications with anticholinergic properties simultaneously. The application of anticholinergic scales to patients with psychiatric disorders has revealed that schizophrenic patients seem to be especially sensitive to anticholinergic cognitive side effects, while elder and depressed patients were more likely to show symptoms of dementia when exposed to higher anticholinergic burden. Unfortunately, these tools appear to have a low parallel reliability, and so they might induce large differences when assessing side effects predictability. In addition, the capacity of these scales to predict central adverse effects is limited due to the fact they poorly or do not differentiate, the ability of treatments to cross the blood-brain barrier. Finally, one last limitation on the validity of these scales is prescription posology is not accounted for side effects considered to be dose dependent. Recently, the MARANTE (Muscarinic Acetylcholine Receptor ANTagonist Exposure) scale has incorporated an anticholinergic burden weighting by posology. Nevertheless, this new model can be criticized, due to the limited number of medications included and due to testing a limited number of potency ranges and dosages for each treatment. Herein, we propose an update to the Anticholinergic Impregnation Scale, developed specifically for the French Psychiatry practice. The scale validation was based on an evaluation of the prescriptions correcting anticholinergic peripheral side effects (constipation, xerostomia and xeropthalmia). This indirect evaluation allowed us to show patients with an anticholinergic impregnation score higher than 5 received significantly more treatments for constipation and xerostomia. This strategy bypasses the bias of a cognitive evaluation in patients with severe mental health disorders. Moreover, the relevance of a tool developed specifically for French psychiatry is justified by the fact that some highly prescribed treatments for mental illness in France (cyamemazine and tropatemine) are strong anticholinergics, and also by the fact they are rarely included in the existing anticholinergic scales. This update of the original scale, published in 2017, includes information whether prescribed drugs cross the blood-brain barrier and thus makes possible a more accurate assessment when evaluating anticholinergic central side effects. Finally, the anticholinergic impregnation scale will soon be integrated into a prescription help software, which is currently being developed to take into consideration dose dependent adverse effects.

Implantation Accuracy of a Lateral Unicompartmental Knee Arthroplasty: A Hoffa´s Fat Pad-Preserving Medial Approach Versus the Transpatellar Lateral Approach

BACKGROUND

A small proportion of patients suffer from isolated lateral osteoarthritis where the sole lateral unicompartmental knee arthroplasty (UKA) is a possible treatment option. There, both a medial and a lateral surgical approach can be considered. This study should answer the question whether the lateral approach is superior to a modified medial approach in terms of implantation accuracy and subjective outcome.

METHODS

In this retrospective study, 175 patients with lateral UKA were included between 2015 and 2020. In 82 patients, the lateral approach was used, and in 93 patients, the medial approach was used. To assess implantation accuracy, different imaging criteria on postoperative radiographs were analyzed. Postoperative patient-related outcome measurements (PROMs) (OKS, LEFS, and EQ5D) were evaluated. Statistical significance was assumed for P < .05.

RESULTS

The tibial implant relation to the tibial plateau diameter in the lateral approach was significantly larger than in the medial approach (23.6% vs 22.2%; P < .001). Significantly more deviations >15° regarding flexion position of the femoral implant (P = .002) and a higher number of deviations of the slope was found (P = .06) in the lateral approach. The lateral approach showed a significantly higher rate of lateral positioning of the femoral component (P = .007). Post-PROMs showed significant improvement in both approaches.

CONCLUSION

The lateral approach is not superior regarding different radiological accuracy criteria. The Hoffa´s fat pad-preserving medial approach showed good results in implantation accuracy and therefore is a good alternative to implant lateral UKA. In addition, significant improvement in PROMs could be demonstrated.

Impact of the COVID-19 pandemic on clinical research in hospitals: observational study in the first epicenter of the epidemic during the general lockdown in France

OBJECTIVE

The COVID-19 epidemic has had a strong impact on the entire healthcare sector in France with priority being given to research for new therapeutic options for COVID-19. Nevertheless, continuity of care for patients suffering from other diseases represents a crucial challenge, and clinical research is no exception in this respect. This study aims to assess the impact of the strict Covid-19 lockdown on non-Covid-19 clinical research in the French University Hospital of Strasbourg.

MATERIALS AND METHODS

Clinical research activity (non-Covid-19) from the point of view of pharmacy department was estimated and compared to the pre-lockdown period. The impact of lockdown was assessed through five indicators: site initiation visits, the initiation of experimental therapies in non-Covid-19 patients, the delivery of non-Covid-19 investigational medical products, the number of drug shipments to patients' homes, and the number of monitoring or closure visits.

RESULTS

During the study period, the number of site initiation visits decreased by 90%, total inclusions by 72%, and delivery of investigational medical products by 30%. During the lockdown period, 15 treatments were sent to patients' homes. Monitoring activity decreased by 98%.

CONCLUSIONS

Although the COVID-19 outbreak has created an incredible momentum in the field of clinical research, research not focused on SaRS-CoV-2 has suffered greatly from this situation. The impact on patients is difficult to estimate but should be further investigated.

Evaluation and Classification of Physical and Psychological Stress in Firefighters using Heart Rate Variability

Stress detection has a huge potential for disease prevention and management, and to improve the quality of life of people. Also, work safety can be improved if stress is timely and reliably detected. The availability of low-cost consumer wearable devices that monitor vital-signs, gives access to stress detection schemes. Heart rate variability (HRV), a stress-related vital-sign, was derived from wearable device data to reliably determine stress-levels. In order to build and train a deployable stress-detector, we collected labeled HRV data in controlled environments, where subjects were exposed to physical, psychological and combined stress. We then applied machine learning to separate and identify the different stress types and understand the relationship with HRV data. The resulting C5 decision tree model is capable of identifying the stress type with 88% accuracy, in a 1-minute time window. For the first time physical and psychological stress can be distinguished with a 1-minute time resolution from smoke-divers, firefighters, who enter high-risk environments to rescue people, and experience intense physical and psychological stress. To improve our model, we created an integrated system to acquire expert labels in real-time from firefighters during their training in a Rescue Maze. A next goal is to transfer the algorithms into generic systems for monitoring and coaching high-risk professionals to improve their stress resilience during training and reduce their risk in the field.

Évaluation de la gravité potentielle des erreurs interceptées par la conciliation des traitements médicamenteux en unité d’hospitalisation de courte durée

Introduction : La conciliation des traitements médicamenteux (CTM) à l’admission hospitalière permet en mode rétroactif d’intercepter puis de corriger des erreurs en comparant la prescription hospitalière initiale à la liste des médicaments pris à domicile par le patient ; cette liste ou ce bilan médicamenteux étant réalisé à partir du croisement de différentes sources. L’objectif de l’étude a été d’évaluer la gravité potentielle des erreurs interceptées par la CTM en unité d’hospitalisation de courte durée (UHCD).

Matériel et méthode : La gravité potentielle des erreurs interceptées a été évaluée à l’aide d’un algorithme clinique selon deux modalités : en considérant uniquement la période d’hospitalisation et sans considération de durée ; c’està- dire comme si l’erreur avait perduré au-delà de la sortie hospitalière du patient. Ces erreurs ont été positionnées selon cinq niveaux de gravité clinique potentielle : mineur, significatif, majeur, critique et catastrophique.

Résultats : La CTM réalisée auprès de 122 patients a permis d’identifier 461 erreurs. Les classes médicamenteuses majoritairement impliquées ont concerné les systèmes cardiovasculaire (n = 151, 32 %), nerveux (n = 103, 22 %) et digestif (n = 86, 18 %). Les principaux types d’erreurs ont été les omissions (n = 381, 83 %,) et les erreurs de dose (n = 57, 12 %). 1,1 % des erreurs auraient pu avoir des conséquences cliniques majeures pour les patients durant la période d’hospitalisation et 8,5 % d’entre elles des conséquences potentiellement majeures ou critiques en considérant un horizon temporel se prolongeant au-delà de l’hospitalisation.

Discussion : L’appréciation de la gravité potentielle des erreurs médicamenteuses traduit l’intérêt clinique de la CTM. Cette évaluation a permis de révéler en UHCD une sinistralité évitée jusque-là méconnue par les équipes médicales.

A High-throughput Screening of a Chemical Compound Library in Ovarian Cancer Stem Cells

BACKGROUND

Epithelial ovarian cancer has a poor prognosis, mostly due to its late diagnosis and the development of drug resistance after a first platinum-based regimen. The presence of a specific population of "cancer stem cells" could be responsible of the relapse of the tumor and the development of resistance to therapy. For this reason, it would be important to specifically target this subpopulation of tumor cells in order to increase the response to therapy.

METHOD

We screened a chemical compound library assembled during the COST CM1106 action to search for compound classes active in targeting ovarian stem cells. We here report the results of the high-throughput screening assay in two ovarian cancer stem cells and the differentiated cells derived from them.

RESULTS AND CONCLUSION

Interestingly, there were compounds active only on stem cells, only on differentiated cells, and compounds active on both cell populations. Even if these data need to be validated in ad hoc dose response cytotoxic experiments, the ongoing analysis of the compound structures will open up to mechanistic drug studies to select compounds able to improve the prognosis of ovarian cancer patients.

Effects of knee orthosis adjustment on biomechanical performance and clinical outcome in patients with medial knee osteoarthritis

BACKGROUND

Valgus bracing in medial knee osteoarthritis aims to improve gait function by reducing the loading of the medial compartment. Orthosis composition and optimal adjustment is essential to achieve biomechanical and clinical effectiveness.

OBJECTIVES

To investigate biomechanical functionality during gait, pain relief and compliance in patients with knee osteoarthritis using a lightweight adjustable knee unloader orthosis.

STUDY DESIGN

Prospective observational clinical trial.

METHODS

Instrumented gait analysis in 22 patients with unilateral medial knee osteoarthritis was performed after a 2-week orthosis acclimatisation period. Kinematics and kinetics during gait as well as force transmission from the orthosis to the knee were analysed. Measurements were performed without, at individualised and at reduced orthosis setting. The assessment was supplemented by patient-related pain sensation and compliance questionnaires.

RESULTS

Orthosis wear significantly reduced the knee adduction moment by up to 20% depending on orthosis adjustment, whereas pain sensation was significantly reduced by 16%. A significant positive correlation was found between force transmissions and knee adduction moment as well as for frontal knee angle. Compliance was good with a main daily use of 2-6 h.

CONCLUSION

The orthosis provides significant biomechanical improvements, pain relief and good patient compliance. Patients had a biomechanical benefit for the individualised and reduced orthosis adjustments. Clinical relevance In patients with medial knee osteoarthritis, a lightweight medial unloader orthosis effectively reduced external knee adduction moment and pain sensation during daily activities. Thus, use of lightweight orthoses effectively supports conservative treatment in medial knee osteoarthritis.

Biosimilar infliximab for the management of rheumatoid arthritis in France: what are the expected savings?

Objectives

Biosimilar infliximab, the first similar biological medicinal product containing monoclonal antibodies to be commercialised, is likely to contribute to a significant reduction in healthcare costs. We aimed to assess the cost savings potential over 1 year of the use of biosimilar infliximab for the treatment of rheumatoid arthritis (RA) patients in Alsace and in France, in a real-life setting.

Methods

The analysis was based on a previously conducted observational study which evaluated the annual cost of the care of patients with RA treated with biological therapies in 2012 in Alsace. Average annual costs to manage RA patients were calculated, taking into account the decrease in the retail price between 2012 and 2015 (as given in the official national price list) and the local negotiated price for biosimilar infliximab. Annual cost savings for different biosimilar prescription scenarios were calculated using 2015 prices.

Results

Management of RA patients with biosimilar infliximab was significantly cheaper than with adalimumab or etanercept (€11 907 vs €12 981 and €13 551, respectively). The projected annual cost savings reached €13.6 million nationally, if all adult RA patients treated with the originator infliximab switched to the biosimilar drug. These savings, if fully reallocated for the treatment of RA, would enable the treatment of 1141 additional patients.

Conclusions

The study showed a positive financial impact of introducing biosimilar infliximab for the treatment of RA patients in France. Such savings could contribute to improved patient care by allowing more patients to be treated without more money being spent.

[Inappropriate prescription and administration of medications in 10 nursing homes in Alsace, France]

BACKGROUND

Medication care is a complicated process in nursing homes. The aim of the study was to offer an overview of inappropriate medication prescription and administration practices in nursing homes in Alsace in order to propose improvement actions to remedy the weaknesses identified.

METHODS

This study was conducted prospectively in 10 nursing homes under contract with community pharmacies in Alsace. The practices of prescription were examined to determine the prevalence of potentially inappropriate medications, inappropriate and contraindicated medication associations. Crushing and opening practices were also assessed, daily treatment costs were calculated.

RESULTS

Two hundred and eighty-four residents were included (age: 87.1 ± 5.6 years). The average number of drugs per resident was 8.1 ± 4.0 (daily treatment cost: 4.19 ± 5.21 €). On average, 1.5 drugs ± 1.4 per prescription were considered as potentially inappropriate (daily treatment cost: 0.49 ± 0.76 €). The contraindication associations concerned 8 % of prescriptions and involved potentially inappropriate drugs in 60 % of cases. Inappropriate associations mainly concerned nervous system drugs. Thirty-three residents were taking more than 2 psychotropic drugs; 23 had more than one benzodiazepine. Regarding drug administration, practices differed from one nursing home to another. Crushing was performed in 8 nursing homes. It concerned 20 residents (7 %) and 69 drugs. In 50 %, the crushing decision was made by nurses without physician or pharmacist supervision. Fifty-seven percent of crushed drugs had a formulation which did not allow crushing (n=39 drugs). The analysis of those items led to the proposal of improvement actions.

CONCLUSION

This study pointed out inappropriate medication practices. Tracking tools for inappropriate clinical practices could be operated by physicians, pharmacists and nursing teams through coordinated multidisciplinary approaches.

Zolpidem test and catatonia

WHAT IS KNOWN AND OBJECTIVE

There is no consensus regarding treatment of catatonia and the main recent therapeutic progress has been the development of the zolpidem diagnostic and therapeutic test. We report on the use of this test in one of our patients.

CASES SUMMARY

Mr. S. suffered from a paranoid schizophrenia. Three episodes of catatonia are described to illustrate the effect of zolpidem in a patient for whom lorazepam was ineffective or inadequate.

WHAT IS NEW AND CONCLUSION

Zolpidem with appropriate testing appears to be a credible alternative to electroconvulsive therapy or increased lorazepam dosing and allows continuation of antipsychotic administration.

Intravenous Methadone for Severe Cancer Pain: A Presentation of 10 Cases

Purpose. Methadone, a synthetic opioid agonist, is an effective alternative to strong opioids (morphine, hydromorphone, oxycodone, and buprenorphine) and is widely available as an oral formulation. Few data have been published so far on the use of intravenous (i.v.) methadone for the management of severe or refractory cancer pain. Methods. We followed 10 consecutives cancer patients with severe pain, treated with IV methadone. All had advanced disease and had already received strong opioids, some in association with ketamine. Pain was assessed at T0, T24 hours, and at the end of the treatment. Results. All patients benefited from the switch to IV methadone with a reduction of pain on VAS after 24 hours (median: 4/10; range 0-5) until the end of the treatment (all cases <3/10). The median starting dose was 100 mg/day (range 20-400) and the final dose remained stable with a median of 100 mg/day (range 27-700). The median duration of IV methadone was 11 days (range 2-59). No cardiac toxicity had been observed. Conclusions. IV methadone is an effective pain relieving alternative for the treatment of severe cancer pain, especially in refractory pain syndrome. Moreover, we did not observe any toxicity (neurological or cardiac) or any other major side effects and the treatment was overall well tolerated. More extensive comparative studies should be planned.

Two-year neonatal outcome following PPROM prior to 25 weeks with a prolonged period of oligohydramnios

BACKGROUND

Improved neonatal survival data have been reported following early preterm prelabour rupture of membranes (PPROM) prior to 25 weeks gestation with a prolonged latency to delivery and persistent oligohydramnios. However, data regarding long-term respiratory and neurological morbidity are lacking.

AIMS

To evaluate the respiratory and neurological outcome data at two years of age in a cohort of infants born following PPROM prior to 25 weeks with a prolonged latency (14 days) to delivery and compare the data to an aged matched group of infants.

METHODS

Retrospective case note analysis over a 43-month period at Saint Luc University Hospital, Brussels.

RESULTS

15 surviving infants born following PPROM were matched to a group of 30 control infants. Although there was no significant difference in the incidence of BPD between the groups (33% vs 27%, p=0.24), the length of hospitalisation, duration of respiratory support and number of hospital readmissions for respiratory indications were all significantly higher for infants born following a prolonged period of oligohydramnios. There were no major anomalies on cranial ultrasound in the PPROM group and Baileys developmental assessment at 20-24 months corrected gestational age showed no difference between the two groups (Mental development index 93.9 vs 94.4 and Psychomotor development index 95.5 vs 95.8 respectively p = ns).

CONCLUSION

Neurodevelopmental outcome appears encouraging in this cohort although these infants are at high risk of prolonged initial hospitalisation and significant respiratory morbidity in the first two-years of life.

[Neonatal Volkmann's syndrome]

BACKGROUND

Acute limb compartment syndrome or Volkmann's ischaemic contracture is an acquired ischaemia of nerve and muscle causes by raised pressure within a closed fascial space. Congenital Volkmann's ischaemic contracture (CVIC) is a rare entity.

PATIENTS AND METHODS

A 2-day-old girl was referred with a problem of the left forearm and arm, which exhibited cold oedema with decreased mobility. Lesions were present at birth and were rapidly complicated by skin necrosis. The mother was taking olazanpine, prazepam and valpromide throughout the entire pregnancy. Delivery was complicated by shoulder dystocia requiring obstetric procedures such as suprapubic pressure, Couder's maneuver and episiotomy. On physical examination her left hemi-thorax, left arm, forearm and hand exhibited marked oedema. A large and well-demarcated bullous, fibrous and ulcerated area of skin necrosis was observed on the elbow fold and on the inner anterior part of the arm. Digital flexion with cyanosis was present. MR angiography revealed extensive oedema of the soft tissue and muscle with fascial effusion, associated with compression of the arm arteries and reduced blood flow in the forearm. A fasciotomy was performed at Day 3 of life. The postsurgical arterial MRI was normal. At Day 10 of life, the patient developed opisthotonos involving spasms and tremors associated with numerous intercritical abnormalities evoking benzodiazepine weaning syndrome. The child's neurological status was stabilized by treatment with phenobarbital and clonazepam. She was subsequently lost to follow-up.

DISCUSSION

CVIC has been ascribed to multiples causes. Mechanical compression is the main recognized factor: amniotic band constriction, umbilical cord loops, compression in utero by a deceased co-twin, malposition of the hand, arm or forearm, local or general factors that can add to extraction problems: brachypelvic disproportion, extraction with forceps, oligo/polyhydramnios, pre-term delivery, pre-eclampsia, caesarean section, premature labour, excessive maternal weight gain or diabetes. Our case emphasized three main points. First, the diagnostic value of early MR angiography in the event of associated extensive tissue oedema, multiple arterial compression and decreased vascular perfusion. Second, the role of shoulder dystocia in triggering the traumatic factor reported for the first time. Third, the role of neuroleptic and anxiolytic treatments taken by the mother during pregnancy. Prazepam is a long-acting benzodiazepine that can cause impregnation and withdraw syndromes in neonates. Impregnation "floppy infant syndrome" is an early event characterized by hypotonia, hypoventilation and lethargy. Hypotonia and decreased foetal movements may favour prolonged pressures and malposition with secondary crush injury during delivery. Maternal medication has not been cited hitherto as an aetiological factor in neonatal compartment syndrome.