Advances in treatments of patients with classical and emergent neurological toxicities of anticancer agents.

The neurotoxicity associated to the anticancer treatments has received a growing body of interest in the recent years. The development of innovating therapies over the last 20years has led to the emergence of new toxicities. Their diagnosis and management can be challenging in the clinical practice and further research is warranted to improve the understanding of their pathogenic mechanisms. Conventional treatments as radiation therapy and chemotherapy are associated to well-known and under exploration emerging central nervous system (CNS) and peripheral nervous system (PNS) toxicities. The identification of the risk factors and a better understanding of their pathogeny through a "bench to bedside and back again" approach, are the first steps towards the development of toxicity mitigation strategies. New imaging techniques and biological explorations are invaluable for their diagnosis. Immunotherapies have changed the cancer treatment paradigm from tumor cell centered to immune modulation towards an efficient anticancer immune response. The use of the immune checkpoints inhibitors (ICI) and CAR-T cells (chimeric antigen receptor) lead to an increase in the incidence of immune-mediated toxicities and new challenges in the neurological patient's management. The neurological ICI related adverse events (n-irAE) are rare but potentially severe and may present with both CNS and PNS involvement. The most frequent and well characterized, from a clinical and biological standpoint, are the PNS phenotypes: myositis and polyradiculoneuropathy, but the knowledge on CNS phenotypes and their treatments is expanding. The n-irAE management requires a good balance between dampening the autoimmune toxicity without impairing the anticancer immunity. The adoptive cell therapies as CAR-T cells, a promising anticancer strategy, trigger cellular activation and massive production of proinflammatory cytokines inducing frequent and sometime severe toxicity known as cytokine release syndrome and immune effector cell-associated neurologic syndrome. Their management requires a close partnership between oncologist-hematologists, neurologists, and intensivists. The oncological patient's management requires a multidisciplinary clinical team (oncologist, neurologist and paramedical) as well as a research team leading towards a better understanding and a better management of the neurological toxicities.

Autoimmune cerebellar hypermetabolism: Report of three cases and literature overview.

We report three cases of vermian cerebellar hypermetabolism in patients with autoimmune encephalitis. One of our patients was positive for anti-Ma2 antibodies and one for anti-Zic4 antibodies while the remaining patient did not present any known antibodies. The seronegative patient deteriorated after immune checkpoint inhibitor treatment for a pulmonary adenocarcinoma and improved with immunosuppressive drugs, which is in favour of an underlying autoimmune mechanism. They all presented with subacute neurological symptoms. Brain magnetic resonance imaging was normal except in one patient, where hyperintensities were present on FLAIR sequence around the third ventricle and the cerebral aqueduct. 18F-FDG brain positron emission tomography with computed tomography (18F-FDG PET-CT) demonstrated an unusual vermian cerebellar hypermetabolism in the three cases. While cerebellar hypermetabolism on 18F-FDG PET-CT has been described in various neurological diseases, such vermian - and more broadly cerebellar - hypermetabolism was seldom described in previous studies on autoimmune encephalitis. When differential diagnoses have been ruled out, this pattern may be of interest for the positive diagnosis of autoimmune encephalitis in difficult diagnostic cases.

Phenotype and genotype of muscle ryanodine receptor rhabdomyolysis-myalgia syndrome.

OBJECTIVES: Rhabdomyolysis and myalgia are common conditions, and mutation in the ryanodine receptor 1 gene (RYR1) is suggested to be a common cause. Due to the large size of RYR1, however, sequencing has not been widely accessible before the recent advent of next-generation sequencing technology and limited phenotypic descriptions are therefore available. MATERIAL & METHODS: We present the medical history, clinical and ancillary findings of patients with RYR1 mutations and rhabdomyolysis and myalgia identified in Denmark, France and The Netherlands. RESULTS: Twenty-two patients with recurrent rhabdomyolysis (CK > 10 000) or myalgia with hyperCKemia (>1.5 × ULN) and a RYR1 mutation were identified. One had mild wasting of the quadriceps muscle, but none had fixed weakness. Symptoms varied from being restricted to intense exercise to limiting ADL function. One patient developed transient kidney failure during rhabdomyolysis. Two received immunosuppressants on suspicion of myositis. None had episodes of malignant hyperthermia. Muscle biopsies were normal, but CT/MRI showed muscle hypertrophy in most. Delay from first symptom to diagnosis was 12 years on average. Fifteen different dominantly inherited mutations were identified. Ten were previously described as pathogenic and 5 were novel, but rare/absent from the background population, and predicted to be pathogenic by in silico analyses. Ten of the mutations were reported to give malignant hyperthermia susceptibility. CONCLUSION: Mutations in RYR1 should be considered as a significant cause of rhabdomyolysis and myalgia syndrome in patients with the characteristic combination of rhabdomyolysis, myalgia and cramps, creatine kinase elevation, no weakness and often muscle hypertrophy.

SMART syndrome: Classic transient symptoms leading to an unusual unfavorable outcome.

BACKGROUND: Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare complication of cerebral radiation therapy that usually presents>10 years after treatment as reversible paroxysmal episodes of neurological dysfunction associated with headaches. CASES: We report here on two cases of SMART syndrome in long-term survivors of high-grade glioma for whom neuropathological data were available. The course of the disease was unfavorable. Although the clinico-radiological picture of SMART syndrome clearly differs from classic cerebral radionecrosis, the gross neuropathological lesions observed in our two patients appeared to be similar to those described in focal radionecrosis. CONCLUSION: SMART syndrome may progress from a benign reversible form to a severe and eventually irreversible form. This severe course may also be confused with tumor progression, and lead to permanent disability and inadequate antitumor treatment. Clinicians should be aware of this latter atypical presentation.

[Perstimulus asystole during electroconvulsive therapy: Clinical case and critical literature review]. / Asystolie perstimulus résultant d'une hypertonie parasympathique au cours des électroconvulsivothérapies : cas clinique, brève revue de la littérature et discussion.

INTRODUCTION: Electroconvulsive therapy (ECT) is most frequently indicated for episodes of melancholic depression, but is also useful in the treatment of maniac syndrome and some schizophrenia subtypes. ECT is part of the treatment of movement disorders, neuroleptic malignant syndrome and even in the treatment of severe conversions. Although the therapeutic results are excellent when used appropriately, the mortality rate is estimated between 2 and 4 for 100,000 shocks. Despite this mortality rate, the benefit-risk ratio remains very positive and serious complications are extremely rare. ECT results in a biphasic cardiological effect: firstly a perstimulus parasympathetic hypertonia contemporary to the seizure's tonic phase, then a phase of contemporary sympathetic hypertonia during the epileptic clonic movement. We will focus on the perstimulus asystole as it is by far the most frequent. Very few cases and even less studies have been referenced in the literature; here, we present a clinical case followed by a discussion. CLINICAL CASE: The patient is in his fifties and has been treated for many years for a unipolar mood disorder with recurrent melancholic depressive episodes. With each new depressive episode, the clinical evolution is rapidly positive after a few sessions of ECT. Maintenance ECT was not retained due to the supra-annual periodicity of the melancholic depressive episodes and rapid recovery after electric treatment. Then, this patient developed another depressive decline in mood comparable to the previous one, despite adapted blood lithium levels associated with a new generation antidepressant treatment. According to his history, a hospitalisation was programmed to carry out a new course of ECT. Considering the short duration of the first seizures, the intensity of the stimulus was progressively increased. At 180 joules, the patient presented an immediate per-stimulus asystole of 20seconds which ceased spontaneously. The specialized cardiologic consultation following the rhythmic episode was reassuring: the patient's cardiac condition remained stable. However, after discussion with the patient and his family, we decided to stop the ECT. Was this a reasonable decision? DISCUSSION: According to the literature, the patient's medical history, sex, psychiatric diagnosis, the shock parameters (level of energy applied, duration of the stimulus, number of shocks) and clinical results, are not predictive factors in the occurrence of an asystole. Concerning the ECT protocol, the vagus nerve seems less stimulated during bifrontal stimulations in opposition to unilateral stimulations. Perasystolic patients are younger and have less prior history of cardiovascular disease or ECG abnormalities. Although the patients receiving ECT are often taking several medications (antipsychotics, benzodiazepines, antidepressants, anticholinergic correctors, calcium channel blockers, loop diuretics, converting enzyme inhibitors), these drugs are not considered as facilitating asystoles. No increase in the frequency of asystole had been observed when taking an average dose psychotropic treatment allowing the continuation of an antidepressant treatment at the recommended dose. Differently, lithium is regularly stopped during the shock phase as it could - even a few days after being stopped - potentiate the effects of succinylcholine and increase the vagal tone. Succinylcholine seems to promote asystole, whilst caffeine, methohexital and trimethaphan do not. The hypersympathetic phase can be controlled by a betablocker (propranolol, esmolol, labetalol) that does not increase the prior risk of asystole. Anticholinergic premedication using atropine does not appear to be systematic and could even potentially induce tachy-dysarrhythmia. However, in the case of perstimulus asystole, most authors recommend continuing the shocks with doses of atropine around 0.4 to 1mg. PHYSIOPATHOLOGY: Vagal stimulation is preferentially central and directly linked to the electric excitation of the lateral dorsal motor nucleus of the vagus nerve. Younger patients with no cardiac history are more at risk. This could be explained by the fact that juvenile tissue conducts electricity more rapidly than senescent (the difference being probably due to the fibrosis and adipose tissue which reduce its conductive capacity). Finally, it is appropriate to question the direct therapeutic aspect of vagal stimulation which constitutes an experimental treatment of resistant depression. CONCLUSIONS: The occurrence of perstimulus asystole is not considered as a serious complication of ECT and therefore as a contra-indication to any future sessions. On the contrary, most authors are campaigning for the continuation of shocks with the possibility of adding prophylactic intravenous atropine. Cardiac arrest reminds us that ECT requires a special attention to its cardiovascular effect, which emphasizes the role of interdisciplinarity between anaesthesiologists and psychiatrists.

Hereditary neuropathy with liability to pressure palsies occurring during military training.

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal-dominant peripheral neuropathy characterized by recurrent isolated nerve palsies, which are precipitated by trivial compression and trauma. Although HNPP has been well-described in literature, it often goes unrecognized. We report a case of HNPP occurring during military training to promote recognition and proper management of this entity.

[Cognitive evaluation during brain radiotherapy in adults: a simple assessment is possible]. / Évaluation cognitive lors de la radiothérapie cérébrale chez l'adulte : vers un outil simple d'évaluation.

Brain irradiation can be used for the treatment of cancers in different protocols: focal radiotherapy, whole brain radiotherapy, with or without additive dose on the tumour. Different modalities (conformational, stereotactic radiosurgery) can be used for curative or prophylactic treatment. Brain radiotherapy leads to cognitive deterioration with subcortical profile. This cognitive deterioration can be associated to radiation-induced leukoencephalopathy on brain MRI. Taking into account radiation induced cognitive troubles is becoming more important with the prolonged survival allowed by treatment improvement. Concerning low-grade gliomas, radiation-induced cognitive troubles appear about 6 years after treatment and occur earlier when the fraction dose is important. Primitive cerebral lymphoma treatment can induce cognitive troubles in 25 to 30% surviving patients. These deficits are more frequent in elderly patients, leading to radiotherapy delay in those patients. Patients treated for brain metastasis often have cognitive impairment before radiotherapy (until 66%), this pretreatment impairment is related to global survival. The use of conformational radiation therapy, particularly with hippocampal sparing is conceptually interesting but has not proved its efficiency for cognitive preservation in clinical trials yet. Stereotactic radiation therapy could be an interesting compromise between metastatic tumoral volume reduction and cognitive preservation. Taking care of radiotherapy induced cognitive troubles is a challenge. Before considering its treatment and prevention, we need to elaborate a way of detecting them using a reliable and easy way. CSCT, a computerized test whose execution needs 90 seconds, could be used before treatment and during the clinical follow-up by the patient's oncologist or radiotherapist. If the patient's performance reduces, he can be oriented to a neurologist in order to perform fuller evaluation of its cognitive capacities and be treated if necessary.