Diaphragmatic weakness related to radiotherapy: 2 cases and a review.

Post-radiation diaphragmatic weakness have rarely been described. We report two cases of post-radiation diaphragmatic weakness from our center, and review the other published cases, computing clinical, electromyography and magnetic resonance imaging data. Including our two cases, seven cases of post-radiation diaphragmatic weakness have been described. Most occurred after mantle-field radiotherapy for Hodgkin lymphoma (5/7), often in associations with chemotherapy (4/7). Other radiations-induced complications were found (5/7) such as brachial plexopathy, cardiac involvement or hypothyroidy. When studied, phrenic nerve conduction studies revealed different profiles, from clearly abnormal responses to limit amplitudes. Imaging can be a useful diagnostic tool, displaying abnormalities with sharp limits matching the radiation field. Data is limited about long-term evolution. Presentation of post-radiation diaphragmatic weakness seems relatively homogeneous. We propose a diagnosis work-up for post-radiation diaphragmatic weakness, to exclude potentially treatable differential diagnoses.

Electro-clinical presentation of hereditary transthyretin related amyloidosis when presenting as a polyneuropathy of unknown origin in northern France.

INTRODUCTION: Hereditary transthyretin related amyloidosis (h-ATTR) classically presents as a small fiber neuropathy with positive family history, but can also be revealed by various other types of peripheral neuropathy. OBJECTIVE: To describe the initial electro-clinical presentation of patients from in a single region (northern France) of h-ATTR when it presents as a polyneuropathy of unknown origin. METHOD: We reviewed the records of patients referred to two neuromuscular centers from northern France with a peripheral neuropathy of unknown origin who were subsequently diagnosed with h-ATTR. RESULTS: Among 26 h-ATTR patients (10 Val30Met, 16 Ser77Tyr), only 14 patients had a suspicious family history (53.8%). The electro-clinical presentation was mostly a large-fiber sensory motor polyneuropathy (92.3%), which could be symmetric or not, length-dependent or not, or associated with nerve entrapment or not. Demyelinating signs were observed in 17 patients (70.8%), among whom nine fulfilled the criteria for a definite diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (37.5%). CONCLUSION: h-ATTR may have a wide spectrum of clinical profiles, and should be considered in the screening of polyneuropathies of unknown origin.

Arterial ischemic stroke in non-neonate children: Diagnostic and therapeutic specificities.

Pediatric arterial ischemic stroke (AIS) is a severe condition, with long-lasting devastating consequences on motor and cognitive abilities, academic and social inclusion, and global life projects. Awareness about initial symptoms, implementation of pediatric stroke code protocols using MRI first and only and adapted management in the acute phase, individually tailored recanalization treatment strategies, and multidisciplinary rehabilitation programs with specific goal-centered actions are the key elements to improve pediatric AIS management and outcomes. The main cause of pediatric AIS is focal cerebral arteriopathy, a condition with unilateral focal stenosis and time-limited course requiring specific management. Sickle cell disease and moyamoya angiopathy patients need adapted screening and therapeutics.

[Pathological patterns in neonatal EEG before 30 weeks of gestational age]. / Les aspects pathologiques de l'EEG du nouveau-né prématuré avant 30 semaines d'âge postmenstruel.

Pathological features on very premature EEG concern background abnormalities and abnormal patterns. Positive rolandic sharp waves keep an important place regarding diagnosis and prognosis. Background abnormalities give essential complementary informations. Unusual patterns (abnormal localisation or morphological aspect, high amplitude) remain early markers of cerebral lesions. Analysis of these pathological features must always take into account treatment given to the baby, which can by itself modify the EEG.

[Place of EEG in the management of arterial ischemic stroke newborn]. / Place de l'électroencéphalogramme dans la prise en charge de l'accident vasculaire ischémique artériel du nouveau-né.

The EEG has a key role in the management of neonatal seizures, which are the typical mode of revelation of neonatal ischemic stroke. The EEG should be started as soon as possible in case of suspected seizure. Some EEG features are evocative of neonatal stroke, typically asymmetry of background activity with the presence of focal spikes and focal seizures. The EEG should be prolonged and always associated with a video as pauci-symptomatic or subclinical seizures are frequent, including some status epilepticus. Video-EEG monitoring is therefore essential to judge the efficacy of anticonvulsant therapy. There is insufficient evidence so far to state if some EEG aspects are predictive of long-term cognitive and epileptic outcomes.

[Biological monitoring and other explorations in the acute phase of a neonatal arterial ischemic stroke (excluding hemostasis)]. / Surveillance biologique et autres explorations à la phase aiguë d'un accident vasculaire cérébral ischémique du nouveau-né (hors hémostase).

Neonatal monitoring and other explorations required just after neonatal arterial ischemic stroke (NAIS) diagnosis remain elusive. This review attempts to propose guidelines on this topic. During neonatal period, three major contexts related to NAIS emerge: 1) Metabolic disorders including hypoglycemia; 2) Early post-natal infections; 3) Cardio-vascular anomalies. Different patient profiles have been defined (typical, atypical and at risk profiles). According to these profiles, a final decisional tree including biological monitoring and complementary explorations has been suggested to caregivers.

Continuous EEG monitoring in children in the intensive care unit (ICU).

Pediatric EEG in the intensive care unit (ICU) requires specific technical requirements in order to yield relevant data depending upon clinical scenario: diagnosis of electroclinical or subclinical seizures, their quantification before and after therapeutic changes and sometimes evaluation of severity of cortical dysfunction. The urgent nature of these indications implies the rapid set-up of the EEG system by qualified staff and possibility of maintaining the electrodes in place during long periods of time. Various techniques are available today for EEG monitoring, the interpretation of which depends on the contribution of an experienced physician. Among recent techniques, those most commonly used are trend curves obtained via signal analysis such as amplitude EEG (a-EEG) and density spectral array (DSA) or compressed spectral array (CSA). Trend curves enable the digital creation of a display graph containing several hours of transformed and compressed EEG recorded data. Visualized on one sole display graph, these trend curves can facilitate the identification of very slow changes in EEG background activity and their variation (alertness cycles, changes linked to treatment administrations) as well as seizure patterns and their quantification. In this chapter, we propose a brief overview of monitoring techniques, followed by a review of the various data yielded by EEG monitoring as well as the relevance of this type of management; finally, detailed clinical indications will be discussed after thorough analysis of the literature.

[Monitoring the neurogenic mixed evoked potentials during surgery of the spine: a good solution?]. / Le monitorage des potentiels évoqués mixtes neurogènes au cours de la chirurgie du rachis: une bonne solution?

Spinal deformity surgery carries a risk of rare but dramatic neurological complications. Intraoperative spinal cord monitoring has been initially performed using somatosensory evoked potentials (SEP). However, false-negative cases have been reported and neurophysiologists supplement SEPs with concurrent motor evoked potentials. The so-called neurogenic mixed evoked potentials (NMEPs) represent an alternate choice, allowing combined monitoring of motor and somatosensory central pathways. They are recorded from a peripheral nerve after spinal cord stimulation. NMEPs have been experimentally and clinically shown to be sensible for detecting spinal cord injury. They are easily and rapidly recorded, and NMEP monitoring may be continuously performed during the critical steps of surgery.

[Severe periventricular leukomalacia: characteristic electroencephalographic features]. / Leucomalacies périventriculaires graves: à propos de quelques aspects électroencéphalographiques particuliers.

Periventricular leukomalacia is an infrequent but severe lesion in the premature neonate. The presence of positive rolandic sharp waves (PRSW) on the electroencephalogram, regardless of their morphology, is a reliable marker of periventricular ischemia, justifying systematic EEG monitoring during the first three weeks of life for infants born at less than 34 weeks of amenorrhea. A retrospective study of 32 premature neonates with extensive cavitary periventricular leukomalacia confirmed the early occurrence of positive rolandic sharp waves in 84% of premature newborns. The mean rate of PRSW was 1.54/min, but showed great variability. In C(Z), these sharp waves which were more frequent or isolated in one case, had the same value as those recorded in C3 or C4. Four neonates had no PRSW, but late periventricular leukomalacia was diagnosed at one month of age. As all these premature infants were born before 29 weeks of amenorrhea, longer EEG monitoring was justified. The prognosis was very poor: 17 newborns died, 11 had motor, sensory and intellectual impairment, and three had motor lesions.

[Indications of electroencephalogram in the newborn]. / Indications de l'électroencéphalogramme en période néonatale. Recommandations du groupe de neurophysiologie clinique de l'enfant.

The electroencephalogram (EEG), an easy-to-use and non invasive cerebral investigation, is a useful tool for diagnosis and early prognosis in newborn babies. In newborn full term babies manifesting abnormal clinical signs, EEG can point focal lesions or specific aetiology. EEG background activity and sleep organization have a high prognostic value. Tracings recorded over long period can detect seizures, with or without clinical manifestations, and differentiate them from paroxysmal non epileptic movements. The EEG should therefore be recorded at the beginning of the first symptoms, and if possible before any seizure treatment. When used as a neonatal prognostic tool, EEG background activity is classified as normal, abnormal (type A and type B discontinuous and hyperactive rapid tracing) or highly abnormal (inactive, paroxysmal, low voltage plus theta tracing). In such cases, the initial recording must be made between 12 and 48 h after birth, and then between 4 and 8 days of life. Severe EEG abnormalities before 12 h of life have no reliable prognostic value but may help in the choice of early neuroprotective treatment of acute cerebral hypoxia-ischemia. During presumed hypoxic-ischemic encephalopathy, unusual EEG patterns may indicate another diagnosis. In premature newborn babies (29-32 w GA) with neurological abnormalities, EEG use is the same as in term newborns. Without any neurological abnormal sign, EEG requirements depend on GA and the mother's or child's risk factors. Before 28 w GA, when looking for positive rolandic sharp waves (PRSW), EEG records are to be acquired systematically at D2-D3, D7-D8, 31-32 and 36 w GA. It is well known that numerous and persistent PRSW are related to periventricular leukomalacia (PVL) and indicate a bad prognosis. In babies born after 32 GA with clinically severe symptoms, an EEG should be performed before D7. Background activity, organization and maturation of the tracing are valuable diagnosis and prognosis indicators. These recommendations are designed (1) to get a maximum of precise informations from a limited number of tracings and (2) to standardize practices and thus facilitate comparisons and multicenter studies.

[Neurogenic mixed evoked potential monitoring during scoliosis surgery: retrospective analysis of 149 cases]. / Utilisation des potentiels évoqués mixtes neurogènes durant la chirurgie des scolioses: analyse rétrospective à propos de 149 cas.

INTRODUCTION: We report a retrospective analysis of spinal cord monitoring with neurogenic mixed evoked potentials (NMEPs) combined with somatosensory evoked potentials (SSEPs) in 149 patients undergoing surgery for spinal deformity. MATERIAL AND METHODS: 149 patients (104 females and 45 males), mean age 28 yrs (13-72 yrs) were studied. NMEPs were elicited by electrical spinal cord stimulation in the rostral part of the surgical field, via two needle electrodes set in the epidural space and in the interspinous ligament above. They were recorded from the sciatic nerve at the knee and the sural nerve at the ankle. SSEPs were recorded from the scalp after stimulation of the posterior tibial nerve at the ankle. A decrease in amplitude of more than 50 p. 100 and/or an increase in latency of more than 10 p. 100 were defined as significant warning criteria. RESULTS: No false-negative result was observed. NMEP modifications did not reach critical value in 143 cases. In 6 cases, significant changes were observed. Moving the stimulation electrodes along the spinal cord allowed spinal lesion localization and helped the surgeon to perform the adapted maneuver, clearly avoiding the occurrence of postoperative neurological defect in 5 of the 6 cases. CONCLUSION: NMEP monitoring is a sensitive and specific method useful for detecting an impending lesion of the spinal cord. NMEPs are also helpful in localizing the spinal level of the lesion. They represent a primary choice tool for neuromonitoring during scoliosis surgery.

A novel quantitative simple brain metric using MR imaging for preterm infants.

BACKGROUND AND PURPOSE: The application of volumetric techniques to preterm infants has revealed brain volume reductions. Such quantitative data are not available in routine neonatal radiologic care. The objective of this study was to develop simple brain metrics to compare brain size in preterm and term infants and to correlate these metrics with brain volumes from volumetric MR imaging techniques. MATERIALS AND METHODS: MR images from 189 preterm infants <30 weeks' gestational age or <1250 g birthweight scanned at term-equivalent age and 36 term infants were studied. Fifteen tissue and fluid measures were systematically evaluated on 4 selected sections. The results were correlated with total brain, gray matter, white matter, and CSF volumes. RESULTS: The mean bifrontal, biparietal, and transverse cerebellar diameters were reduced (-11.6%, 95% confidence interval [CI], -13.8% to -9.3%; -12%, 95% CI, -14% to -9.8%; and -8.7%, 95% CI, -10.5% to -7% respectively) and the mean left ventricle diameter was increased (+22.3%, 95% CI, 2.9%-41.6%) in preterm infants (P < .01). Strong correlations were found between the bifrontal and biparietal measures with total brain tissue volume, whereas the size of the ventricles and the interhemispheric measure correlated with CSF volume. Intraobserver reliability was high (intraclass correlation coefficients [ICC], >0.7), where interobserver agreement was acceptable for tissue measures (ICC, >0.6) but lower for fluid measures (ICC, <0.4). CONCLUSIONS: Simple brain metrics at term-equivalent age showed smaller brain diameters and increased ventricle size in preterm infants compared with full-term infants. These measures represent a reliable and easily applicable method to quantify brain growth and assess brain atrophy in this at-risk population.

Paramyotonia congenita with an SCN4A mutation affecting cardiac repolarization.

Paramyotonia congenita (PC) is linked to mutations of the skeletal muscle voltage-gated sodium channel alpha-subunit gene SCN4A. The authors report a family where the proband and three of her four children have PC (mutation R1448C) and present repolarization abnormalities at electrocardiogram. They demonstrate that the SCN4A alpha-subunit gene is expressed in normal human heart. Cardiac consequences of mutations of the SCN4A gene may be insignificant in standard conditions, but critical if patients with PC are treated with drugs inducing QT prolongation.

The effects of desflurane on the nervous system: from spinal cord to muscles.

UNLABELLED: Monitoring of motor pathways via muscle contraction recording is sensitive to anesthetics, particularly volatile anesthetics. However, the specific action sites of these anesthetics on the spinal cord and the peripheral nervous system are not well known in humans. Therefore, we studied proximal and distal motor and sensory nerve conduction, neuromuscular junction transmission, and spinal cord excitability (H/M amplitude ratio and F-wave amplitude and persistency) using standard neurophysiological techniques in 10 patients who underwent orthopedic surgery. Muscle potentials evoked by spinal cord stimulation were recorded in five additional patients. Desflurane was introduced to achieve end-tidal concentration of 3.7% and 7.4%, in 50% O2/N2O and in 100% O2. Measurements were obtained before desflurane administration and 20 min after obtaining a stable level of each concentration. Peripheral nerve conduction and neuromuscular function were not significantly affected by desflurane. However, spinal cord excitability was significantly decreased by desflurane administration (H/M ratio 37% +/- 9%, 12% +/- 5%, 7% +/- 4% at desflurane concentration 0.0%, 3.7%, and 7.4% in 100% O2, respectively). Muscle potentials evoked by spinal cord stimulation were abolished by desflurane. These data rule out the possibility that desflurane specifically alters peripheral nerve conduction or synapse transmission at the neuromuscular junction. They demonstrate that desflurane acts preferentially at the level of the spinal motoneuron. IMPLICATIONS: We used neurophysiological techniques to assess the effects of desflurane on spinal cord conduction and excitability, motor and sensory peripheral nerve conduction, and neuromuscular transmission. Our data demonstrate that desflurane acts preferentially at the level of the spinal motoneuron, providing useful information for neurophysiological monitoring and immobilization during surgery and for minimum alveolar anesthetic concentration definition.