Management of catatonia in Huntington disease: A scoping review.

Huntington disease (HD) is a hereditary neurodegenerative disorder characterized by motor, psychiatric, and cognitive symptoms. The genetic defect responsible for the onset of the disease, expansion of CAG repeats in exon 1 of the gene that codes for huntingtin on chromosome 4, has been unambiguously identified. On the other hand, the mechanisms by which the mutation causes the disease are not completely understood yet. However, defects in energy metabolism of affected cells may cause oxidative damage, which has been proposed as one of the underlying molecular mechanisms that participate in the etiology of the disease. In our effort to investigate the extent of oxidative damage occurring at the protein level, we used a parallel proteomic approach to identify proteins potentially involved in processes upstream or downstream of the disease-causing huntingtin in a well established HD mouse model (R6/2 transgenic mice). We have demonstrated that the expression levels of dihydrolipoamide S-succinyltransferase and aspartate aminotransferase increase consistently over the course of disease (10-week-old mice). In contrast, pyruvate dehydrogenase expression levels were found to be decreased in 10-week-old HD transgenic mice compared with young (4-week-old) mice. Our experimental approach also led to the identification of oxidatively modified proteins. Six proteins were found to be significantly oxidized in old R6/2 transgenic mice compared with either young transgenic mice or non-transgenic mice. These proteins are alpha-enolase, gamma-enolase (neuron-specific enolase), aconitase, the voltage-dependent anion channel 1, heat shock protein 90, and creatine kinase. Because oxidative damage has proved to play an important role in the pathogenesis and the progression of Huntington disease, our results for the first time identify specific oxidatively modified proteins that potentially contribute to the pathogenesis of Huntington disease.

ECT FOR THE TREATMENT OF SOMATIC SYMPTOM DISORDER AND UNINTENTIONAL WEIGHT LOSS IN OLDER ADULTS: 2 CASE REPORTS

Psychopathology in Verified Huntington's Disease Gene Carriers

<h3></h3> Huntington disease (HD) is an autosomal dominant neurodegenerative disorder, characterised by motor, psychiatric and cognitive symptoms. HD is caused by a CAG repeat expansion in the first exon of the HTT gene, resulting in an expanded polyglutamine tract at the N-terminus of the huntingtin protein. Typical disease onset is around mid-life (adult-onset HD) whereas onset below 21 years is classified as juvenile HD. While much research has been done on the underlying HD disease mechanisms, little is known about regulation and expression levels of huntingtin RNA and protein. In this study we used a unique collection of human post-mortem HD brain tissue and fibroblast cells to investigate huntingtin mRNA and protein expression, as well as huntingtin antisense isoforms. In adult-onset HD brain samples, there was only a small but significant lower expression of mutant huntingtin mRNA compared to wild-type huntingtin mRNA, while protein expression levels were equal. Juvenile HD subjects did show a lower protein expression of mutant huntingtin compared to wild-type huntingtin protein. Additionally, in brain tissue we did not find any evidence for a reduced expression of huntingtin antisense, as we showed HTTAS_v1 expression in a homozygous HD patient. Finally, we have identified a novel huntingtin antisense isoform and named it HTTAS_v2.2. Our study shows an intricate mechanism of huntingtin RNA and protein regulation of expression with slightly less mutant huntingtin mRNA, but equal wild-type and mutant huntingtin protein levels in adult-onset HD, indicating subtle differences in huntingtin protein expression between adult-onset and juvenile HD.

​TheThe gene for Huntington's disease (HD) was discovered in 1993 and ever since has been puzzling researchers intent on understanding its effects. The mutation, an expanded CAG repeat, is translated into an extended polyglutamine tract in the huntingtin protein (HTT), which leads to protein misfolding, accumulation of sticky protein aggregates in both cytoplasm and nucleus, and degeneration of neurons, first in the brain's striatum and later in the cortex and elsewhere. There are no disease-altering treatments and no single hypothesis of disease pathogenesis. In a new study, Michal Mielcarek, Gillian Bates, and colleagues elucidate a key role for the transcription regulator histone deactylase 4 (HDAC4)—not within the nucleus as you might expect, but instead in the cytoplasm. HDAC4 acts in the cytoplasm of brain cells to exacerbate the Huntington's disease (HD) pathogenic process. Reduction of HDAC4 levels ameliorates cytoplasmic-related HD phenotypes and improves survival, but does not change gene transcription. One prominent feature of HD molecular pathology is a global transcriptional dysregulation, likely driven in part by reduced histone acetylation. To counterbalance that effect, researchers have investigated whether inhibiting HDACs might be therapeutic, and one HDAC inhibitor has produced promising results in preclinical trials in models of HD. There are 11 different mammalian HDACs, and in order to better characterize their individual contributions to HD, the authors examined the effects of partially or completely knocking out each one. They found that reducing HDAC4 by 50% in a mouse model of HD reduced neuronal dysfunction of striatal neurons and delayed loss of motor function of the mice, allowing them to perform a balancing task at 12 weeks of age as well as untreated mice who were a month younger. Treatment also extended lifespan by about 20%, a significant improvement in this aggressive disease model of HD. Antibodies against HDAC4 and either mutant or wild-type HTT indicated that HDAC4 bound to mutant HTT in either soluble or aggregated form, but not to normal protein. Like HTT, HDAC4 includes a polyglutamine region, and it is likely that its interaction with mutant HTT is through the reciprocal attractions between these regions. Reducing HDAC4 reduced the total burden of HTT aggregates throughout the brain while increasing the amount of soluble HTT, indicating that treatment delayed the aggregation process. The work thereby finds a novel route to modulating the toxicity of HTT. HDAC4 remains sequestered in the cytoplasm until it is called upon to shuttle into the nucleus to take part in regulating transcription. Co-labeling HDAC4 and mutant HTT indicated that they localized together in the cytoplasm, but not the nucleus, and that reducing HDAC4 reduced aggregation in the cytoplasm while leaving the number of nuclear aggregates unchanged. This ability of the work to separate cytoplasmic pathologies from nuclear ones is an important advance in this field. Surprisingly, reducing HDAC4 had no effect on the widespread transcriptional dysregulation that led HD researchers to consider HDAC inhibitors in the first place. It did, however, have one potentially important effect on gene expression: it largely restored the levels of brain-derived neurotrophic factor, a growth factor that neurons need for survival and that is known to be lost in HD. This effect is likely mediated through a cytoplasmic, not nuclear, mechanism, based on previous work on this pathway in HD; further work will be needed to understand it in detail. These results have several implications for understanding and treating HD. There is no shortage of hypotheses of pathogenic mechanisms in HD, and this new mechanism is unlikely to be the sole cause of neuronal damage. But the discovery of a strictly cytoplasmic pathogenic effect of mutant HTT is new and will likely bring more attention to the cytoplasm as a site for further research. The demonstration that shifting the balance of mutant protein from aggregated to soluble forms has a beneficial effect further informs a long-standing debate in disorders of protein misfolding, about whether aggregates are toxic or protective, and will likely accelerate exploration of therapies to promote disaggregation. As mentioned, there are currently no disease-modifying therapeutics available for HD. The discovery that reducing HDAC4 has therapeutic effects in the HD model tested here—which happens to be a gold standard model in which most therapeutics fail when tested—will spur efforts to mimic this effect with small molecules to obstruct the interaction of HDAC4 and mutant HTT, or antisense therapies designed to prevent production of HDAC4 protein. Mielcarek M, Landles C, Weiss A, Bradaia A, Seredenina T, et al (2013). HDAC4 Reduction: A Novel Therapeutic Strategy to Target Cytoplasmic Huntingtin and Ameliorate Neurodegeneration. doi:10.1371/journal.pbio.1001717

Huntington Disease (HD) is a dominantly inherited, relentlessly progressive neurodegenerative disease. Caused by a polyglutamine expansion in the huntingtin protein (mutant huntingtin, mhtt), HD pathogenesis impairs function in the cerebral cortex and in medium spiny neurons of the striatum. HD is also characterized by the transcriptional dysregulation of a number of genes. Of these genes, the silencing of genes related to mitochondrial function is believed to explain metabolic dysfunction in rodent models of HD. Here we show that transglutaminase 2 (TG2), which is upregulated in HD, exacerbates transcriptional dysregulation by acting as a selective corepressor of nuclear genes. In a cellular model of HD, TG2 inhibition by RNA knockdown, genetic deletion, or administration of a novel, peptide-based irreversible TG2 inhibitor (ZDON), de-repressed two established regulators of mitochondrial function, PGC-1α and cytochrome c. We showed that TG2 must localize to non-coding or coding regions of these mitochondrial metabolic genes to silence their transcription. As expected, TG2 inhibition reversed the increased susceptibility of HD mouse cells and human HD myoblasts to the mitochondrial toxin, 3-nitroproprionic acid (3-NP); however, protection mediated by TG2 inhibition was not associated with improved mitochondrial bioenergetics. Indeed, an unbiased array analysis indicated that TG2 inhibition leads to normalization of not only mitochondrial genes but of nearly 40% of genes that are dysregulated in HD mouse striatal neurons, including chaperone and histone genes. Indeed, TG2 interacts directly with Histone H3 in the nucleus. Moreover, TG2 inhibition significantly attenuated photoreceptor degeneration in a Drosophila model of HD and protected mouse HD striatal neurons (YAC128) from NMDA-induced toxicity. Altogether these findings demonstrate that TG2 mediates its deleterious effects in HD by contributing to broad transcriptional dysregulation of genes representing many cellular functions. These studies define a novel HDAC-independent epigenetic strategy for treating neurodegeneration.

ECT in Elderly Patients With Schizophrenia

Our work suggests an important new link between the RCAN1 gene and Huntington disease. Huntington disease is caused by expansion of glutamine repeats in the huntingtin protein. How the huntingtin protein with expanded polyglutamines (mutant huntingtin) causes the disease is still unclear, but phosphorylation of huntingtin appears to be protective. Increased huntingtin phosphorylation can be produced either by inhibition of the phosphatase calcineurin or by activation of the Akt kinase. The RCAN1 gene encodes regulators of calcineurin, and we now demonstrate, for the first time, that RCAN1-1L is depressed in Huntington disease. We also show that RCAN1-1L overexpression can protect against mutant huntingtin toxicity in an ST14A cell culture model of Huntington disease and that increased phosphorylation of huntingtin via calcineurin inhibition, rather than via Akt induction or activation, is the likely mechanism by which RCAN1-1L may be protective against mutant huntingtin. These findings suggest that RCAN1-1L "deficiency" may actually play a role in the etiology of Huntington disease. In addition, our results allow for the possibility that controlled overexpression of RCAN1-1L in the striatal region of the brain might be a viable avenue for therapeutic intervention in Huntington disease patients (and perhaps other polyglutamine expansion disorders).

Electroconvulsive therapy (ECT) is an important therapy for treatment-resistant depression and is especially effective for elderly individuals with depression. This is the first US nationally representative description of ECT in the elderly. Using 2014-2015 Medicare claims data, we compared elderly individuals with major depressive disorder (using ICD-9 and ICD-10 codes) who received ECT with those who did not on demographic and clinical measures. We characterized treatment patterns by setting and the proportion of individuals receiving index and continuation/maintenance courses, subtherapeutic courses of ECT, and post-ECT follow-up care. Of all Medicare beneficiaries aged 65 years and older diagnosed with depression in 2014-2015, 7,817 (0.41%) received 1 or more ECT sessions. Compared to the general population of elderly Medicare beneficiaries with depression, recipients of ECT were slightly younger and more likely to be male, non-Hispanic, and white and live in a zip code with a higher median income. Among those who received any ECT, 33.7% received < 5 total treatments. Of those who received an index ECT treatment, 33.7% received a continuation/maintenance course of ECT, while 60.9% received some form of post-ECT follow-up treatment (additional ECT or new psychotropic medication). Receipt of psychotherapy was the strongest predictor of those who received ≥ 5 ECT treatments (adjusted odds ratio = 1.43; 95% CI, 1.22 to 1.67). Despite substantial evidence of efficacy, ECT use remains rare among elderly patients with depression. Findings suggest a potential need for efforts to increase the proportion of patients receiving adequate courses of ECT and evidence-based post-ECT follow-up care.

INTRODUCTION Electroconvulsive therapy (ECT) is a clinical procedure where a small dose of electric current is passed through the brain for a brief period to induce seizures for therapeutic purposes in psychiatric (and certain neurological) conditions. Modified ECT is the modern form of ECT where the electrical stimulus is given under general anesthesia and muscle relaxation. This is one of the most effective treatments for many psychiatric conditions. Modern modified ECT is a safe treatment when practiced with adequate knowledge, skills, and expertise. Following the basic standards of ECT practice is necessary for better clinical outcomes including minimal cognitive adversities. This guideline document is aimed at enabling consistent, safe, and effective practice of ECT in patients in applicable psychiatric disorders. METHODS These guidelines are developed as part of the initiative of Clinical Practice Guidelines (CPG) subcommittee of Indian Psychiatric Society. The initial draft guideline was developed by the authors. The information was sourced from key research articles, national/international guidelines on psychiatric care, and ECT. No formal systematic literature search was conducted. The current guideline was prepared to suit the existing Indian mental health care system and legislations. The draft was further presented and discussed in the in-person workshop of CPG-2022. The draft was revised following the discussion in the workshop based on the consensus-based recommendation method. This guideline is not a directive or mandatory instruction but a guidance document for professional practitioners administering ECT. This is not a full and complete review of ECT procedure. But it is intended to improve patient outcomes by facilitating best practice standards by maximizing benefits and minimizing adversities. USE OF ELECTROCONVULSIVE THERAPY Indications Table 1 shows the indications for ECT. Evidence exists for the efficacy of ECT in depressive episodes, manic episodes, and acute exacerbations of psychosis in schizophrenia. Treatment-resistant depression, mania, and schizophrenia, including clozapine-resistant schizophrenia, are well-recognized indications,[1-6] with evidence from comparative trials (comparison across types of ECT or with waitlisted patients). ECT should not be withheld until the failure of several medication/psychotherapy trials in severe depression. Health economics suggest that it is beneficial to consider ECT as a second or third line agent in severe depression. ECT is considered as first-line (primary) treatment for emergency psychiatric conditions across diagnoses. These include high suicidality, catatonia, excitement, aggression, poor oral intake, acute psychotic symptom exacerbations, and severe physical debilitation secondary to psychiatric disorders.[7-13] The rigor of the evidence base is limited for such indications due to ethical and pragmatic considerations in conducting sham-controlled trials in these emergency life-threatening transdiagnostic situations. It may be noted that almost all international standard guidelines suggest ECT as a first-line treatment option for these indications.[8-13]Table 1: Indications of ECTPredictors of response In general, older age, psychotic symptoms, and shorter episode duration are predictors of response to ECT. Melancholic features and greater baseline depressive symptom severity are also associated with better ECT response. Past good response to ECT is considered a good predictor of response for the current episode. Continuation/Maintenance (C/M) ECT should be considered for patients with a history of severe, recurrent episodes who have failed to remain well on medications.[14] ECT is a first-line treatment when rapid and/or definitive response to avert harm to self/others is needed. Acute suicidal risk, agitation, catatonia, and deteriorating physical status secondary to psychiatric conditions are some of such situations. After an acute course of ECT, C/M treatment with pharmacotherapy and/or psychotherapy is needed. All the indications mentioned above have to be individualized and should be based on the clinical needs, patient's preferences, and putative risk of adverse effects. ECT staffing ECT without anesthesia and muscle relaxation is now prohibited under the Mental Health Care Act, 2017. Hence, the staffing shown in Table 2 is advisable for administering modified ECT.Table 2: Staffing for ECTTreatment site and equipment The treatment suite ideally involves three distinct areas, but which are nearby or closely connected:[9,10] a. Waiting/preparation room: should have the following facilities: i. Waiting area for patients and caregivers ii. Space for assessment: for interviewing, examining, verifying the records, and to ensure adequate preparation iii. Sphygmomanometer and stethoscope b. ECT administration room i. ECT apparatus including bite block, electroencephalogram (EEG) monitor, and ECG monitor ii. Anesthetic agents (e.g., thiopentone, propofol, etomidate, ketamine, isoflurane, sevoflurane, etc.) and muscle relaxants (along with succinylcholine, at least one nondepolarizing agent like atracurium or rocuronium should be available) iii. Emergency medication tray to manage uncontrolled hypertension, hypotension, cardiac arrhythmia, cardiopulmonary arrest, anaphylactic shock, prolonged seizure, and status epilepticus. This should include intravenous fluids, epinephrine, dopamine, atropine or glycopyrrolate, cholinesterase inhibitors (neostigmine, physostigmine), anticonvulsants (lorazepam, diazepam, phenytoin), steroids, beta blockers (esmolol, labetalol), alpha-blockers (prazosin, clonidine), vasodilators (nitroglycerin, hydralazine), antiarrhythmics (lidocaine), analgesics (paracetamol), antiemetics (domperidone, metoclopramide), antihistamines (chlorpheniramine, cetirizine), bronchodilators (aminophylline) among others) iv. Vitals monitoring: sphygmomanometer, reflex hammer, oxygen saturation, ECG v. Intubation set: oral and naso-pharyngeal airways vi. Oxygen delivery system with intermittent positive pressure ventilation capabilities through a mask as well as endotracheal tubes vii. Suction apparatus, iv infusion set, syringes with needles, cotton and gauze pads, hand gloves. viii. Defibrillator ix. Portable cots/beds, disposable containers c. Recovery room: should have all items iii to ix listed above Informed consent (Supplements 1–4) Written informed consent has to be taken before initiating ECT based on principles of shared decision-making. Consent should be taken following due procedures in accordance with the highest ethical standards and applicable laws/regulations. Written information material may be provided to the patient and caregivers, and adequate time should be provided for reverting with any clarifications. Information should be provided regarding the anticipated benefits and possible short-term and long-term adverse effects of modified ECT, including possible risks with both anesthesia and ECT, in the given individual. Discussion on the type of ECT, modification procedure, electrode placement, and expected outcomes should be included in this process. Unless the patient disagrees, it is recommended to make caregivers a part of the consenting process. If a patient does not have the capacity to consent, the same needs to be documented. The advance directives, if any, have to be examined and, in accordance with that, consent may be obtained from the nominated representative. In the case of minors, oral/verbal assent (as per the age) should be obtained along with written informed consent from parents/nominated representative; the decision about initiating ECT has to be taken only after concurrence by two independent psychiatrists or a psychiatrist + a physician, and due permission from the mental health review board as per the law. As and when a patient regains the capacity to consent or attains 18 years of age, his/her consent has to be obtained for continuing ECT sessions then onwards.[15,16] Consent has to be obtained again before initiating C/M ECT, as the clinical condition, purpose (consolidation/relapse prevention), and character of treatment (frequency of ECT sessions and end-point) would have changed. Pre-ECT evaluation (Supplement 5): This should be performed as close to the ECT course as possible. Psychiatric and physical evaluation Psychiatric evaluation is needed to ascertain indications. Rating scales can be used to determine these indications systematically and measure the changes during the ECT course. If the patient has received ECT in the past, details of the electrode placement and electrical parameters in earlier ECTs, level of achieved response, and associated cognitive deficits would guide the current course of ECT. It is important to evaluate the psychotropic medications that can potentially interfere with anesthesia and ECT. For instance, anticonvulsants increase seizure threshold; antipsychotics like chlorpromazine and clozapine are known to be pro-convulsants; lithium can increase the risk of postictal delirium; tricyclic antidepressants are known to increase the risk of cardiac adverse events during ECT/anesthesia. Physical examination is needed to identify any relative contra-indications and prevent complications [Table 3]. It should mandatorily involve fundoscopic examination along with other systemic examinations. Dental evaluation for loose or missing teeth, cardiovascular examination for arrhythmias, assessment for neurological comorbidities, and pulmonary clinical evaluation are mandatory.Table 3: Clinical conditions requiring caution while administering ECTPreanesthetic evaluation is recommended to plan for an anesthetic agent and a muscle relaxant. Also, suitable investigations or interventions can be planned in the presence of medical conditions associated with a substantial risk for general anesthesia-related complications. Liaison with other specialist physicians if deemed is necessary by the psychiatrist/anesthetist. Baseline cognitive screen Monitoring of cognitive adverse effects would be necessary for patients receiving ECT. Baseline knowledge of cognitive abilities is crucial in attributing the changes in cognitive abilities with ECT. Hindi Mental Status Examination and Mini Mental Status Examination are simple tools for monitoring, but are not sensitive to subtle cognitive changes associated with ECT. Montreal cognitive assessment battery (MoCA) and brief ECT cognitive screen are assessment tools used internationally. "Battery for ECT-Related Cognitive Deficits" (B4ECT RECODE) is a tool validated in the Indian population and is recommended to be used during the initiation and course of ECT.[10] Investigations For general anesthesia: hemoglobin levels, blood sugar, electrolytes, blood urea, and serum creatinine would facilitate the detection of common risk-enhancing medical comorbidities but are not mandatory. Similarly, X-ray, electrocardiography, echocardiogram, and other tests would be indicated based on physical evaluation and associated medical comorbidities TREATMENT PROCEDURE ECT is mandatorily used as a modified procedure, as per the law in India. The modification involves using muscle relaxants to reduce the neuromuscular injuries and using anesthetic agents to induce sedation and amnesia for the procedure involving muscle relaxation and electrical stimulation. a. Anesthesia Preparation before anesthesia [Figure 1, Table 4 and Supplement 6]The procedure may be anxiety provoking. So, reassure patients while initiating the procedure including while securing iv access and placing the mask for oxygenation.An ideal anesthetic agent for ECT would be rapidly inducing and short acting (early emergence from effects of anesthesia), has a good amnesic effect and stable systemic/cerebral hemodynamics during ECT, and would not have any effects on seizure threshold. Tables 5 and 6 provide information helpful in selecting anesthetic agents.[17]A combination of propofol and ketamine called ketofol can be used to balance seizure duration and hemodynamic effects. Adjunctive short-acting opiates (remifentanyl, alfentanil, fentanyl) or dexmedetomidine have dose-sparing effects and can be used, but they need more evidence of their exact role in ECT. The differential effects of anesthetic agents are dependent on their dose, and this needs to be considered while choosing the anesthetic agent.Muscle relaxation is an important component of modified ECT. Ideal muscle relaxants should have the ability to avoid musculoskeletal injury without affecting cerebral seizure activity and provide rapid recovery without residual paralysis. Succinylcholine (0.3–1 mg/kg) is a preferred muscle relaxant due to its rapid onset and recovery. Nondepolarizing muscle relaxants may be considered in certain conditions. These include peudocholinesterase deficiency, recent organophosphorus poisoning, severe, widespread burns, hypercalcemia, severe neuromuscular disease or injury (e.g., quadriplegia, amyotrophic lateral sclerosis, muscular dystrophy), history of malignant hyperthermia in the patient or his/her family. In a patient with suspected/known history of a recent (4 weeks) suicide attempt and referred to ECT, a high suspicion of organophosphorous poisoning should be considered. There are reports of prolonged apnea even after 4 weeks of poisoning. Clinicians may consider the assessment of pseudocholinesterase level when in doubt or may use of nondepolarizing agents in such cases.Pseudocholinesterase level can be assessed in patients with high suspicion (e.g., patients belonging to Arya Vysya community, an earlier history of prolonged apnea). Routine determination of pseudocholinesterase level is not recommended. Routine prophylactic use of anticholinergics (atropine/glycopyrrolate), beta-blockers, calcium channel blockers, nitrates, hydralazine, and ganglionic blockers for cardiovascular stability is not recommended. Wherever used, the rationale for using such an agent should be noted. b. ECT Dosing The protocol of ECT varies considerably and choice on the protocols should be based on individual needs of a given patient. The rapidity of needed response, effectiveness, and potential cognitive adverse effects of the protocols should guide the choice. Rather than any set of protocols, it is important to have knowledge of each parameter in the protocol, and personalization of protocol can be done based on clinical situations.[18,19] i. Electrical Parameters A brief or ultrabrief pulse is strongly recommended and should be administered with a constant current device. Sinewave ECT and constant voltage systems are not recommended in the modern practice of ECT due to safety concerns. Electrical charge is generally considered as a linear measure and chief parameter of dosing. But this approach is faulty, and the combination of electric current intensity, pulse width, pulse frequency and train duration (number of pulses) along with electrode placement (stimulation site), frequency of sessions and duration of session should be carefully considered in choosing a protocol. Electrical current intensity: Historically, 500–1000 mA has been used in the practice of ECT. Most devices come with a default current of 800–900 mA. The current intensity is known to linearly correlate with tolerability, cognitive as well as seizure quality but is generally kept constant and not modified during dose incrementation. Recently, low amplitude (200–400 mA) has been explored as part of individualized low-amplitude seizure therapy.[20] Its clinical utility is yet to be understood. Pulse width: ECT is classified as brief pulse (0.5–2 ms) and ultrabrief pulse (0.2–0.4 ms). Pulse width is likely to have a linear effect on cognitive adverse effects with broader widths being associated with worse cognitive effects. Ultrabrief pulse of 0.3 ms has been shown to have a cognitive advantage over brief pulses with right unilateral placement in depressive disorders. But the antidepressant efficacy may be compromised with it. A lower range of brief pulse (0.5–1 ms) may be considered optimal to obtain a rapid clinical effect. But when cognitive effects are of major concern, a stimulus with ultra-brief pulse width may be chosen.[21] Pulse frequency: The number of biphasic pulses every second is the electrical parameter that is inverse of the interpulse interval. It is an important electrical parameter that generally ranges from 20 to 240 pulses/s (10–120 Hz, i.e., bidirectional pulse pair per second). Stimuli with lower frequencies are generally more efficient, i.e., a seizure can be elicited at a lesser charge with lower frequency than with higher frequency when all other parameters are kept constant. Many ECT devices in the default increment method involve an increase in frequency. ECT clinicians should be aware of this aspect while using a default way of increasing stimulus charges to address the issue of high seizure threshold. Train duration: This is the most commonly modified parameter to set the dose. Generally, the pulse duration is limited by the devices. Most devices have a range of 0.2–8 s, but certain devices come with the highest limit of up to 16 s. No limit has been examined/recommended on the highest duration. An increase in charge is achieved by increasing train duration till the upper limit of the device is reached. The number of pulses: It is directly a factor of train duration and will also be influenced by pulse frequency. The number of pulses may intuitively suggest a direct correlation with seizure. But as "crowding of pulses" is inefficient in eliciting seizure, the number of pulses by itself may not be a good indicator for setting electrical parameters. Directionality: The default ECT parameter widely applied is bidirectional current. There are preliminary trials of unidirectional current – anodal at one site and cathodal at the other. But the evidence is limited to suggest the clinical utility of unidirectional current. Patterned doses: Bursts of pulses are provided similar to theta bursts in transcranial magnetic stimulation. The available evidence is for continuous pulses with similar intervals, which is supported by most commercially available devices. Currently, patterned pulses cannot be recommended for routine clinical application. ii. Electrode placement The electrodes are placed in different ways [Figure 2]:[22-25] 1. Bilateral: Bitemporal: Classical method. One electrode is placed in the frontotemporal region (one above the line the and placed on above on an line to the line two Clinical trials have shown that is if not more effective than placement, but with lesser cognitive effects in patients with mania, as well as schizophrenia. right placement of electrodes with the on the region and right on frontotemporal is Evidence from systematic is for this One electrode is placed on the right frontotemporal region and electrode 1 right to of of two one two and other This is shown to have lesser cognitive but the dose when provided as an ultrabrief pulse for that of as right unilateral on the This is to be to the right This placement can be when and is needed more than It is also considered in the right brain The evidence for the efficacy of unilateral ECT is available only for depression. The evidence of unilateral ECT is for other common indications or iii. of ECT ECT is discussed in of charge A higher charge is associated with better efficacy and higher cognitive adverse effects. But as discussed the charge is not a linear measure but a combination of electrical parameters [Figure 3]. Table Preparation for ECT of of anesthesia agents in choosing for and of anesthetic agents used during 1: of 2: ECT electrode 3: Electrical charge intensity pulse width pulse frequency train duration. The dose for optimal efficacy through ECT sessions is considered with to the seizure threshold; efficacy is also dependent on pulse width and electrode charge seizure is recommended in ECT with brief pulse ECT width of 1 ms or evidence a of a higher charge seizure when a lower range of ms) is used with ECT. There is evidence that a seizure is with ultrabrief ms) ECT, with the evidence available for right unilateral ECT, in depression. For right unilateral ECT with brief pulse width, electrical charge is to be considered the seizure threshold. Ultrabrief at 0.3 ms) is to be effective and may not be advisable with the existing the dose increment has to for a current pulse and pulse Hence, the dose should also be a of train duration. But most of the standard devices have a of train duration at in default and they increase pulse frequency to increase the duration. Most have used these default and this guideline should be with are needed to ascertain this This will be the recommended method in The session can be in the dose needed for seizure can be used as guidance for the dose of may be with higher in and with may be in sessions can be provided at as discussed on the and of the different are There is a need to be in using the as medications and anesthetic agents may the seizure threshold. The stimulus should have the same pulse width, pulse and electrode from which the was high This a high dose, commonly the for all the The use of a high should be only for patients with medical conditions in which of is a Dosing from A high dose will be administered at the The and would be In the are to at the dose a similar This be a better to the high it is c. and and i. ECT procedure [Figure of ECT method is recommended for seizures by the in the right unilateral from muscle a direct measure of seizure activity and is recommended from at least two and to the is only a channel is a channel is can have due to muscle and other Hence, should be used to seizure quality seizure should be given more than any duration. A good quality seizure, even of shorter has been to be in of of seizure and of seizure to adequate seizure is to be of clinical or quality seizure involves different is a seizure during after the the stimulation. This will be by will which will A will the with the of and The should be even in the presence of method of and of the in the case of unilateral electrode is preferred in modified ECTs, as it of from the of ECT stimulus till the of the in any part of the in the be considered for seizure duration. quality seizure involves the of seizure activity in quality seizure will have [Figure 1: involving with increasing 2: high amplitude bursts at to 3: with for to the – a line is The onset of this the of The is recovery from to theta to of is better in patients than in of If is or seizure even after 20 of of electrical then may be by increasing the stimulus dose. onset seizure should be If the seizure is of low quality or the seizure is to one of the or to the region at higher may be after s. may be till the patient of relaxant. Generally, to can be If of or dose, can be from the It may be noted that reduce the quality of If the seizures are brief (e.g., and if the patient is the expected clinical response, then with a higher dose need not be on the same after adequate seizure, called the ECT is not recommended. in of unilateral ECT, would not be necessary on the of This be considered only conditions like malignant or In the case of a prolonged seizure than can be if a seizure s. and should be closely till the complete of seizure. A seizure may be using or the anesthetic agent used for If the patient is on or or may be considered. to anesthetic agents may also be considered. lateral and in the ECT suite should under the care of an till is the patient can be to the recovery ii. Monitoring in the recovery room Monitoring of the should be pulse blood and oxygen ECG should be in patients of cardiac should be for arrhythmia, seizure, and should be until the patient regains full during the procedure should be musculoskeletal injuries and should be assessed for recovery to baseline or baseline before the patient from the recovery iii. the course of ECT The number of should not be but should be based on the needs of individual in of clinical and cognitive and other adverse effects should be at least a during the course of ECT. ECT may be at any time if complete clinical is If clinical is not a of ECT sessions should be provided in acute before

Huntington's disease (HD) arises from expanded CAG repeats in exon 1 of the Huntingtin (HTT) gene. The resultant misfolded HTT protein accumulates within neuronal cells, negatively impacting their function and survival. Ultimately, HTT accumulation results in cell death, causing the development of HD. A nonhuman primate (NHP) HD model would provide important insight into disease development and the generation of novel therapies due to their genetic and physiological similarity to humans. For this purpose, we tested CRISPR/Cas9 and a single-stranded DNA (ssDNA) containing expanded CAG repeats in introducing an expanded CAG repeat into the HTT gene in rhesus macaque embryos. Analyses were conducted on arrested embryos and trophectoderm (TE) cells biopsied from blastocysts to assess the insertion of the ssDNA into the HTT gene. Genotyping results demonstrated that 15% of the embryos carried an expanded CAG repeat. The integration of an expanded CAG repeat region was successfully identified in five blastocysts, which were cryopreserved for NHP HD animal production. Some off-target events were observed in biopsies from the cryopreserved blastocysts. NHP embryos were successfully produced, which will help to establish an NHP HD model and, ultimately, may serve as a vital tool for better understanding HD's pathology and developing novel treatments.

Huntington disease (HD) is an incurable neurodegenerative disorder caused by expansion of CAG repeats in huntingtin (HTT) gene, resulting in expanded polyglutamine tract in HTT protein. Although, HD has its common onset in adulthood, subtle symptoms in patients may occur decades before diagnosis, and molecular and cellular changes begin much earlier, even in cells that are not yet lineage committed such as stem cells. Studies in induced pluripotent stem cell (iPSC) HD models have demonstrated that multiple molecular processes are altered by the mutant HTT protein and suggested its silencing as a promising therapeutic strategy. Therefore, we aimed to generate HD iPS cells with stable silencing of HTT and further to investigate the effects of HTT knock-down on deregulations of signaling pathways e.g., p53 downregulation, present in cells already in pluripotent state. We designed a gene silencing strategy based on RNAi cassette in piggyBAC vector for constant shRNA expression. Using such system we delivered and tested several shRNA targeting huntingtin in mouse HD YAC128 iPSC and human HD109, HD71, and Control iPSC. The most effective shRNA (shHTT2) reagent stably silenced HTT in all HD iPS cells and remained active upon differentiation to neural stem cells (NSC). When investigating the effects of HTT silencing on signaling pathways, we found that in mouse HD iPSC lines expressing shRNA the level of mutant HTT inversely correlated with p53 levels, resulting in p53 level normalization upon silencing of mutant HTT. We also found that p53 deregulation continues into the NSC developmental stage and it was reversed upon HTT silencing. In addition, we observed subtle effects of silencing on proteins of Wnt/β-catenin and ERK1/2 signaling pathways. In summary, we successfully created the first mouse and human shRNA-expressing HD iPS cells with stable and continuous HTT silencing. Moreover, we demonstrated reversal of HD p53 phenotype in mouse HD iPSC, therefore, the stable knockdown of HTT is well-suited for investigation on HD cellular pathways, and is potentially useful as a stand-alone therapy or component of cell therapy. In addition, the total HTT knock-down in our human cells has further implications for mutant allele selective approach in iPSC.

[This corrects the article on p. 253 in vol. 10, PMID: 28848389.].

Huntington’s disease (HD) is a dominant genetic neurodegenerative disease caused by a mutation in the exon 1 of the huntingtin gene. The clinical symptoms, such as motor disturbances (chorea), cognitive decline and psychiatric impairments are usually developed by the patients in mid-life. Mutant huntingtin protein presents an amplification of a polyglutamine repeat at its N-terminus, which induces conformational changes and leads to neurotoxicity, impairment of cell homeostasis and neuronal cell death. The neuropathology of HD is characterized by a progressive degeneration of the brain starting from the striatum and spreading to other regions such as cortex, hypothalamus and cerebellum. In addition to the diffused brain atrophy, HD patients are also affected by multiple peripheral symptoms which contribute to worsening disease progression and eventually lead to death approximately two decades after onset. The mechanisms leading to the toxicity induced by mutant huntingtin are not well understood. However the acquisition of a misfolded conformation and the formation of intracellular inclusions constituted by shorter fragments of the mutant protein are considered important in the neurodegenerative process. In my thesis project I have investigated mechanisms to enhance the cellular degradation of mutant huntingtin. A second focus was on the development of an immunoassay to detect and quantify aggregates in HD models. I analyzed the data obtained form a high through-put screen aimed to identify small molecular weight compounds decreasing mutant huntingtin levels in cells. Among all compounds screened, only inhibitors of heat shock protein 90 (Hsp90) showed a significant effect on mutant huntingtin clearance. I therefore investigated the mechanisms of Hsp90 chaperone inhibition and the reduction of soluble mutant huntigtin levels. Data from biochemical assays demonstrated that mutant huntingtin degradation is enhanced upon compound treatment and that the protein is cleared through the ubiquitin-proteasome system. This was independent from the heat shock response induced after pharmacological Hsp90 inhibition. Co-immunoprecipitation experiments suggested that mutant huntingtin is a client protein of Hsp90. The results were replicated in different cellular models including full length mutant huntingtin expressed from the endogenous locus, thus highlighting the importance of Hsp90 in stabilizing soluble mutant huntingtin and suggesting the possible application of Hsp90 inhibitors as therapies in HD. In the second project I developed a sensitive method to detect mutant protein aggregates in HD models. To this purpose I implemented the already established time resolved fluorescence resonance energy transfer (TR-FRET) based immunoassay for the detection of soluble mutant and wild-type huntingtin. A mixture of either donor or acceptor fluorophore labeled single monoclonal antibody directed against an epitope exposed on the huntingtin aggregate surface was used. This strategy allowed for energy transfer and therefore a measurable TR-FRET signal, only in presence of mutant aggregated protein. I could demonstrate the sensitivity of the bioassay on a microtiter set up both as a single assay and in a duplex combination with the previously developed TR-FRET assay for soluble huntingtin. I applied the TR-FRET for aggregated huntingtin to samples from R6/2 and HdhQ150 mice, expressing exon 1 and full length mutant huntingtin, respectively. In brain homogenates from both models there was an age-dependent, inverse correlation between soluble and aggregated mutant huntingtin. These findings supported the importance of the relation between aggregated and soluble protein in disease progression. Furthermore, I detected the inverse correlation also in peripheral tissues of R6/2 mice where the presence of aggregates was previously demonstrated with other methods. An in-depth analysis of R6/2 samples in a combination of TR-FRET and size exclusion chromatography suggested a differential specificity of the two antibody combinations used for different aggregate populations. The TR-FRET method provides a new means to characterize the aggregation process as well as to test the efficacy of possible disease modifying treatments for HD.

Effects of continuation electroconvulsive therapy on quality of life in elderly depressed patients: A randomized clinical trial