Loss of hypothalamic MCH decreases food intake in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is associated with impaired energy metabolism, including weight loss and decreased appetite which are negatively correlated with survival. Neural mechanisms underlying metabolic impairment in ALS remain unknown. ALS patients and presymptomatic gene carriers have early hypothalamic atrophy. The lateral hypothalamic area (LHA) controls metabolic homeostasis through the secretion of neuropeptides such as orexin/hypocretin and melanin-concentrating hormone (MCH). Here, we show loss of MCH-positive neurons in three mouse models of ALS based on SOD1 or FUS mutations. Supplementation with MCH (1.2 µg/d) through continuous intracerebroventricular delivery led to weight gain in male mutant Sod1G86R mice. MCH supplementation increased food intake, rescued expression of the key appetite-related neuropeptide AgRP (agouti-related protein) and modified respiratory exchange ratio, suggesting increased carbohydrate usage during the inactive phase. Importantly, we document pTDP-43 pathology and neurodegeneration in the LHA of sporadic ALS patients. Neuronal cell loss was associated with pTDP-43-positive inclusions and signs of neurodegeneration in MCH-positive neurons. These results suggest that hypothalamic MCH is lost in ALS and contributes to the metabolic changes, including weight loss and decreased appetite.

Parakinesia: A Delphi consensus report.

Abnormal movements are intrinsic to some forms of endogenous psychoses. Spontaneous dyskinesias are observed in drug-naïve first-episode patients and at-risk subjects. However, recent descriptions of spontaneous dyskinesias may actually represent the rediscovery of a more complex phenomenon, 'parakinesia' which was described and documented in extensive cinematographic recordings and long-term observations by German and French neuropsychiatrists decades before the introduction of antipsychotics. With the emergence of drug induced movement disorders, the description of parakinesia has been refined to emphasize the features enabling differential diagnosis with tardive dyskinesia. Unfortunately, parakinesia was largely neglected by mainstream psychiatry to the point of being almost absent from the English-language literature. With the renewed interest in motor phenomena intrinsic to SSD, it was timely not only to raise awareness of parakinesia, but also to propose a scientifically usable definition for this phenomenon. Therefore, we conducted a Delphi consensus exercise with clinicians familiar with the concept of parakinesia. The original concept was separated into hyperkinetic parakinesia (HPk) as dyskinetic-like expressive movements and parakinetic psychomotricity (PPM), i.e., patient's departing from the patient's normal motion style. HPk prevails on the upper part of the face and body, resembling expressive and reactive gestures that not only occur inappropriately but also appear distorted. Abnormal movements vary in intensity depending on the level of psychomotor arousal and are thus abated by antipsychotics. HPk frequently co-occurs with PPM, in which gestures and mimics lose their naturalness and become awkward, disharmonious, stiff, mannered, and bizarre. Patients are never spontaneously aware of HPk or PPM, and the movements are never experienced as self-dystonic or self-alien. HPk and PPM are highly specific to endogenous psychoses, in which they are acquired and progressive, giving them prognostic value. Their differential diagnoses and correspondences with current international concepts are discussed.

[Some scientific highlights from early 2022: A selection by MD/Pharmacy-PhD students]. / L'actualité scientifique de ce début 2022 vue par les étudiants de l'AMPS.

TITLE: L'actualité scientifique de ce début 2022 vue par les étudiants de l'AMPS. ABSTRACT: L'AMPS rassemble les étudiants en santé qui, en plus de suivre une formation clinique, se forment à la recherche scientifique dans le but de devenir soignant-chercheurs. Elle promeut les interactions multidisciplinaires entre la santé et les sciences, et permet une émulation scientifique entre les étudiants des différentes facultés, aux profils, compétences et idées variés.

The polysemous concepts of psychomotricity and catatonia: A European multi-consensus perspective.

Current classification systems use the terms "catatonia" and "psychomotor phenomena" as mere a-theoretical descriptors, forgetting about their theoretical embedment. This was the source of misunderstandings among clinicians and researchers of the European collaboration on movement and sensorimotor/psychomotor functioning in schizophrenia and other psychoses or ECSP. Here, we review the different perspectives, their historical roots and highlight discrepancies. In 1844, Wilhelm Griesinger coined the term "psychic-motor" to name the physiological process accounting for volition. While deriving from this idea, the term "psychomotor" actually refers to systems that receive miscellaneous intrapsychic inputs, convert them into coherent behavioral outputs send to the motor systems. More recently, the sensorimotor approach has drawn on neuroscience to redefine the motor signs and symptoms observed in psychoses. In 1874, Karl Kahlbaum conceived catatonia as a brain disease emphasizing its somatic - particularly motor - features. In conceptualizing dementia praecox Emil Kraepelin rephrased catatonic phenomena in purely mental terms, putting aside motor signs which could not be explained in this way. Conversely, the Wernicke-Kleist-Leonhard school pursued Kahlbaum's neuropsychiatric approach and described many new psychomotor signs, e.g. parakinesias, Gegenhalten. They distinguished 8 psychomotor phenotypes of which only 7 are catatonias. These barely overlap with consensus classifications, raising the risk of misunderstanding. Although coming from different traditions, the authors agreed that their differences could be a source of mutual enrichment, but that an important effort of conceptual clarification remained to be made. This narrative review is a first step in this direction.