The mechanisms through which auricular vagus nerve stimulation protects against cerebral ischemia/reperfusion injury

Previous studies have shown that vagus nerve stimulation can improve patients' locomotor function.The stimulation of the auricular vagus nerve,which is the only superficial branch of the vagus nerve,may have similar effects to vagus nerve stimulation.However,the precise mechanisms remain poorly understood.In this study,rat models of cerebral ischemia/reperfusion injury were established by modified Longa ligation.Twenty-four hours later,7-day auricular vagus nerve stimulation was performed.The results showed that auricular vagus nerve stimulation promoted the secretion of acetylcholine,inhibited the secretion of interleukin-1β,interleukin-6,and tumor necrosis factor-α,and reduced connexin 43 phosphorylation in the ischemic penumbra and motor cortex,promoting locomotor function recovery in rats with cerebral ischemia/reperfusion injury.These findings suggested that auricular vagus nerve stimulation promotes the recovery of locomotor function in rats with cerebral ischemia/reperfusion injury by altering the secretion of acetylcholine and inflammatory factors and the phosphorylation of connexin 43.This study was approved by the Animal Use and Management Committee of Shanghai University of Traditional Chinese Medicine on November 8,2019(approval No.PZSHUTCM191108014).     

Enhancing Rehabilitative Therapies with Vagus Nerve Stimulation

Pathological neural activity could be treated by directing specific plasticity to renormalize circuits and restore function. Rehabilitative therapies aim to promote adaptive circuit changes after neurological disease or injury, but insufficient or maladaptive plasticity often prevents a full recovery. The development of adjunctive strategies that broadly support plasticity to facilitate the benefits of rehabilitative interventions has the potential to improve treatment of a wide range of neurological disorders. Recently, stimulation of the vagus nerve in conjunction with rehabilitation has emerged as one such potential targeted plasticity therapy. Vagus nerve stimulation (VNS) drives activation of neuromodulatory nuclei that are associated with plasticity, including the cholinergic basal forebrain and the noradrenergic locus coeruleus. Repeatedly pairing brief bursts of VNS sensory or motor events drives robust, event-specific plasticity in neural circuits. Animal models of chronic tinnitus, ischemic stroke, intracerebral hemorrhage, traumatic brain injury, and post-traumatic stress disorder benefit from delivery of VNS paired with successful trials during rehabilitative training. Moreover, mounting evidence from pilot clinical trials provides an initial indication that VNS-based targeted plasticity therapies may be effective in patients with neurological diseases and injuries. Here, I provide a discussion of the current uses and potential future applications of VNS-based targeted plasticity therapies in animal models and patients, and outline challenges for clinical implementation.     

氟西汀对急性缺血性脑卒中患者运动功能的影响

目的 探讨氟西汀改善急性缺血性脑卒中患者肢体运动功能的作用.方法 急性缺血性脑卒中患者60例,随机分成氟西汀组和对照组,对照组予常规药物治疗和康复治疗,氟西汀组加用氟西汀20 mg qd po,分别在给药前、给药后30 d、给药后90 d进行FMMS评分,评价2组运动功能情况.结果 发现在给药后90 d,氟西汀组FMMS评分明显高于对照组,2组比较差异有统计学意义（P＜0.05）.结论 对于以运动功能障碍为主要表现的急性缺血性脑卒中患者,早期给予小剂量氟西汀口服（20 mg/d）并配合物理疗法,对患者的运动功能恢复有一定帮助.     

Are There Differences in Long-Term Functioning and Recovery Between Hemorrhagic and Ischemic Stroke Patients Receiving Rehabilitation?

ObjectivePrevious research suggested better recovery in functioning of patients with hemorrhagic as compared to ischemic stroke. Now that more effective acute treatment for ischemic stroke, i.e. thrombolysis and thrombectomy, has become available, this observational cohort study aimed to examine if current rehabilitation outcomes differ between patients with hemorrhagic and ischemic stroke.Materials and MethodsThe Barthel Index, 4 domains of the Stroke Impact Scale (SIS) and the EuroQol 5Dimensions were completed in all consecutive patients who received stroke rehabilitation at start of rehabilitation and during follow-up (for Barthel Index at discharge, SIS and EuroQol 5D after three and six months). Outcomes and recovery (i.e. change of scores between baseline and last follow-up) were compared between patients with hemorrhagic stroke and ischemic stroke (total and categorized by initial hospital treatment) using the Kruskall Wallis test. In addition, recovery was compared between ischemic and hemorrhagic stroke in multiple regression analyses with bootstrapping.ResultsBaseline functioning did not differ between 117 patients with a hemorrhagic stroke, 118 ischemic stroke patient treated with reperfusion therapy, and 125 ischemic stroke patients without reperfusion therapy. There were no differences in functioning at follow-up nor in recovery concerning the Barthel Index, SIS domains ‘mobility’, ‘communication’, ‘memory and thinking’ and ‘mood and emotions’, and EuroQoL 5D between the three categories.ConclusionsIn a rehabilitation population the recovery and functioning at three or six months did not differ between ischemic stroke patients and hemorrhagic stroke patients, regardless of the hospital treatment they had received.     

功能性电刺激结合重复经颅磁刺激用于缺血性脑卒中偏瘫患者步行障碍恢复的临床观察

目的 观察功能性电刺激结合重复经颅磁刺激用于缺血性脑卒中偏瘫患者步行障碍恢复的临床疗效。方法 将53例缺血性脑卒中偏瘫患者随机分为对照组、治疗组、假治疗组3组,在均接受常规康复训练的基础上对照组接受功能性电刺激治疗,治疗组接受功能性电刺激及重复经颅磁刺激治疗,假治疗组接受功能性电刺激及假重复经颅磁刺激治疗; 治疗前及治疗8周后采用步态运动学参数、时间参数、距离参数及Amer-Lindholm分级对3组患者的下肢综合运动功能进行评定。结果 治疗前3组患者步态运动学参数、时间参数、距离参数及Amer-Lindholm分级评分均无显著差异(P>0.05),治疗8周后3组患者上述指标明显改善且治疗组改善幅度明显优于其余2组(P<0.05)。结论 功能性电刺激联合重复经颅磁刺激治疗有利于改善缺血性脑卒中偏瘫患者的步行运动功能。     

功能性电刺激结合康复踏车训练对卒中急性期患者下肢功能的影响

目的 观察和探讨功能性电刺激（functional electrical stimulation,FES）结合康复踏车训练对卒中急性 期患者下肢功能的影响。 方法 将120例卒中急性期偏瘫患者采用随机数字表法分为对照组和观察组。两组均接受常规药物 治疗。对照组患者采用Bobath技术为主的常规康复训练,主要包括桥式训练、坐站训练、常规踝背屈 训练等,每日训练1次,每次45 min,每周训练5 d,训练2周。观察组患者在对照组康复治疗基础上给予 FES结合康复踏车系统训练,每次20 min,每周训练5 d,训练2周。分别于治疗前和治疗后采用功能性 步行量表（functional ambulation category,FAC）、Fugl-meyer下肢功能评定量表（Fugl-Meyer assessment, FMA）、Barthel指数评定量表进行评分并比较。 结果 ①治疗前,2组患者各项指标组间比较差异均无统计学意义;②治疗后,对照组和治疗组患者 的FAC评分、下肢FMA评分、Barthel指数评分均较本组治疗前有显著改善;治疗后,观察组上述指标显 著优于对照组（均P＜0.001）。 结论 功能性电刺激结合康复踏车训练能显著地提高卒中急性期患者下肢功能,从而提高患者日 常生活活动能力。     

Left-hand somatosensory stimulation combined with visual scanning training in rehabilitation for post-stroke hemineglect: a randomised, double-blind study

The aim of this randomised, double-blind study was to investigate the therapeutic effectiveness of left-hand electrical stimulation for patients with post-stroke left visuo-spatial neglect. This approach was hypothesised to enhance activation of the right hemisphere attention system and to improve visual exploration of extrapersonal space. Participants (n = 40) in the study were in a relatively early stage of recovery from their first right hemisphere stroke, and were randomly assigned to the experimental (E) or control (C) group. Group E received conventional visual scanning training combined with electrostimulation of the left hand, while Group C received scanning training with sham stimulation. Their visuo-spatial neglect was assessed twice, prior to the rehabilitation programme and on its completion, using cancellation tests and a letter-reading task. The effect of electrostimulation on hemineglect was assessed following a single administration and after a month-long rehabilitation programme. Although the immediate effect of stimulation was poor, after a month-long rehabilitation period we found significantly greater improvement in Group E patients than in Group C patients. Interestingly, the presence of hemisensory loss did not weaken the observed effect. Therefore, we claim that contralesional hand stimulation combined with visual scanning was a more effective treatment for hemineglect rehabilitation than scanning training alone.     

氟西汀联合奥扎格雷钠对急性缺血性卒中后抑郁患者神经功能及心理状态的影响

目的 分析氟西汀联合奥扎格雷钠对急性缺血性卒中后抑郁患者神经功能及心理状态的影响.方法 选取2018年2月～2020年2月期间本院收治的113例急性缺血性卒中后抑郁患者作为研究对象,采用随机数字表法将研究对象分为观察组和对照组.对照组56例患者给予奥扎雷纳静脉滴注治疗,观察组57例患者增加氟西汀联合治疗,均持续治疗12...     

MEG response to median nerve stimulation correlates with recovery of sensory and motor function after stroke.

OBJECTIVE: Hemiparesis due to damage by stroke in primary motor cortex (MI) or its underlying projections presents a problem for functional neuroimaging technologies that attempt to evaluate the neurophysiological basis for restoration of motor function. Traditional assessments of MI function require patients to move their fingers, hands, or limbs, which can be either impossible or markedly compromised after stroke. We recently demonstrated in normal subjects that magnetoencephalography (MEG), a non-invasive neuromagnetic functional imaging technique, detects neuronal response elicited by electrical median nerve stimulation in MI, as well as primary somatosensory cortex (SI). In the present study, we used the MEG response from median nerve stimulation to investigate the recovery of primary motor and somatosensory in acute ischemic stroke patients. METHODS: Twelve patients with unilateral ischemic strokes that affected sensorimotor functions of their hand were studied in the acute stage (4.4+/-1.2 days, mean+/-SD) and during a 1-month follow-up (38.6+/-5.6 days, except for one patient's follow-up done 6 month after stroke). RESULTS: Among the multiple cortical sources localized after median nerve stimulation, one source localized to SI and another localized to the vicinity of MI. Changes in the source strengths of the first component post-stimulus of MI and SI correlated with the extent of recovery of sensorimotor functions as determined by neurological exams. CONCLUSIONS: This study provides a novel way of indirectly assessing MI function using MEG during the acute stroke phase, when many patients often cannot perform motor tasks due to paralysis.     

Assessment of safety and feasibility of non-invasive vagus nerve stimulation for treatment of acute stroke

BackgroundNon-invasive vagus nerve stimulation (nVNS) using a hand-held stimulator placed on the neck is an FDA-approved treatment for primary headache disorders. The safety of nVNS is unknown in stroke patients.ObjectiveTo assess the safety and feasibility of nVNS for the acute treatment of stroke.MethodsTR-VENUS (clinicaltrials.gov identifier NCT03733431) was a randomized, sham-controlled, open-label, multicenter trial conducted in patients with acute ischemic stroke (IS) or intracerebral hemorrhage (ICH). Patients were randomly assigned to standard-dose nVNS, high-dose nVNS, or sham stimulation. The primary endpoint was a composite safety outcome defined as bradycardia or reduction in mean arterial blood pressure during treatment or progression of neurological or death within 24 h of treatment. The feasibility endpoints were the proportion of eligible subjects receiving nVNS within 6 h of symptom onset and the proportion completing all pre-specified treatment doses. Efficacy assessments included infarct growth from baseline to 24 h after treatment.ResultsSixty-nine patients (61 IS, 8 ICH) completed the study. The composite safety outcome was achieved in 32.0% in sham and 47.7% in nVNS group (p = 0.203). Treatment was initiated in all but two randomized patients. All dosed subjects received 100% of prespecified stimulations. A non-significant reduction in infarct growth was observed in the high-dose nVNS group (184.2% in sham vs. 63.3% in high-dose nVNS; p = 0.109).ConclusionsThe results of this study suggest that nVNS may be safe and feasible in the setting of acute stroke. These findings support further development of nVNS as a potential treatment for acute ischemic stroke.     

低频电刺激联合早期康复训练治疗急性脑梗死

目的 探讨双乳突法头部低频电刺激及早期康复训练对急性脑梗死患者神经功能缺损程度及日常生活能力(ADL)恢复的影响.方法 90例急性脑梗死患者,随机分为低频电刺激及早期康复训练组(A组)、低频电刺激组(B组)和对照组(C组),每组30例.A、B两组均采用低频电刺激、常规药物治疗,A组在发病48h内进行早期康复训练.分别观察治疗后第21天神经功能缺损评分及ADL的变化.结果 三组在治疗前神经功能缺损评分、ADL评分差异均无统计学意义(P＞0.05),A组治疗后神经功能缺损评分、ADL评分明显优于B组及对照组,差异有显著统计学意义(P＜0.01).结论 低频电刺激及早期康复训练对急性脑梗死患者具有明显的临床疗效.     

Left-hand somatosensory stimulation combined with visual scanning training in rehabilitation for post-stroke hemineglect: A randomised,double-blind study

The aim of this randomised, double-blind study was to investigate the therapeutic effectiveness of left-hand electrical stimulation for patients with post-stroke left visuo-spatial neglect. This approach was hypothesised to enhance activation of the right hemisphere attention system and to improve visual exploration of extrapersonal space. Participants (n = 40) in the study were in a relatively early stage of recovery from their first right hemisphere stroke, and were randomly assigned to the experimental (E) or control (C) group. Group E received conventional visual scanning training combined with electrostimulation of the left hand, while Group C received scanning training with sham stimulation. Their visuo-spatial neglect was assessed twice, prior to the rehabilitation programme and on its completion, using cancellation tests and a letter-reading task. The effect of electrostimulation on hemineglect was assessed following a single administration and after a month-long rehabilitation programme.

Although the immediate effect of stimulation was poor, after a month-long rehabilitation period we found significantly greater improvement in Group E patients than in Group C patients. Interestingly, the presence of hemisensory loss did not weaken the observed effect. Therefore, we claim that contralesional hand stimulation combined with visual scanning was a more effective treatment for hemineglect rehabilitation than scanning training alone.     

下肢康复机器人训练对脑卒中偏瘫患者下肢运动功能的康复作用

目的探讨下肢康复机器人训练对脑卒中偏瘫患者下肢运动功能的康复作用。方法共60例发病6个月的脑卒中偏瘫患者随机接受常规康复训练联合减重步行训练(BWSTT组,30例)或常规康复训练联合下肢康复机器人训练(Robot组,30例),分别于训练前和训练8周时采用Fugl-Meyer下肢评价量表(FMA-LE)评价下肢运动功能、Berg平衡量表(BBS)评价平衡功能、下肢康复机器人力矩反馈系统评价下肢肌力。结果与训练前相比,两组患者训练8周时FMA-LE(P=0.000)和BBS(P=0.000)评分、步态周期中患侧髋关节(P=0.000)和膝关节(P=0.000)反馈力矩值均增加;与BWSTT组相比,训练8周时Robot组仅步态周期中患侧髋关节(P=0.000)和膝关节(P=0.000)反馈力矩值增加。结论常规康复训练联合减重步行训练和下肢康复机器人训练均可以改善脑卒中偏瘫患者下肢运动功能,下肢康复机器人训练在提高下肢肌力方面优于减重步行训练。     

Motor response to amphetamine treatment, task-specific training, and limited motor experience in a postacute animal stroke model

Despite advances in acute treatment of ischemic cerebrovascular events, the most common clinical outcome is disabling neurological impairment. Despite experimental evidence that psychostimulant treatment can positively affect recovery rate after focal brain lesions, beyond rehabilitation therapies there are no currently accepted medical treatments indicated for diminishing neurological impairment after clinically established stroke. To test the effect of amphetamine, task-specific training, limiting motor experience, and their interaction on motor recovery in a postacute animal model of stroke, animals were nonaversively trained in beam walking before a unilateral photochemical sensorimotor cortex lesion and tested for 10 days after lesion. Animals were randomized to groups receiving: a single session of motor training 24 h after lesion; a single injection of amphetamine 2 mg/kg 24 h after lesion; beam-walking experience limited to testing on days 1 and 10 after lesion; and groups that received amphetamine treatment combined with training or combined with limited experience. Motor recovery was maximally enhanced by training, delayed by amphetamine treatment, and most negatively affected by limiting beam-walking experience during the recovery period. These findings support physical training after stroke, indicating that limiting physical activity negatively affects motor recovery and raises questions about the role of stimulant treatment to enhance motor recovery in the postacute phase after stroke.     

心房颤动对不同时间窗内急性缺血性脑卒中患者静脉溶栓疗效的影响

目的探讨急性缺血性脑卒中合并心房颤动患者不同时间窗内静脉溶栓的疗效差异。方法选取急性缺血性脑卒中行静脉溶栓治疗患者172例,根据发病-溶栓时间窗差异分为3组,时间窗分别为≤3.0 h(观察A组)、>3.0~4.5 h(观察B组)、>4.5 h(观察C组),对其中合并心房颤动者溶栓疗效进行评估分析。结果3组患者溶栓24 h后出血转化结果、溶栓3个月时神经功能结局良好率、病死率均无明显差异(P>0.05);溶栓时间窗>3 h者,心房颤动可显著增加患者发生PH型、HI型出血转化发生率,差异有统计学意义(P<0.05);单因素分析显示,合并心房颤动可造成溶栓时间窗≤4.5 h患者神经功能结局不良发生率增加,差异有统计学意义(P<0.05)。多因素分析显示,合并心房颤动与不同时间窗急性缺血性脑卒中患者静脉溶栓治疗后神经功能结局不良发生情况无明显相关性(P>0.05)。结论溶栓时间窗仍是影响急性缺血性脑卒中患者静脉溶栓疗效的重要因素,对于溶栓时间窗≤3.0 h者,合并心房颤动不会对溶栓疗效造成影响;对于发病-溶栓时间>3 h者,心房颤动可能造成患者溶栓后出血风险增加。     

Auricular transcutaneous electrical nerve stimulation in depressed patients: a randomized controlled pilot study

Invasive vagus nerve stimulation has been demonstrated to be an effective treatment in major depressive episodes. Recently, a novel non-invasive method of stimulating the vagus nerve on the outer canal of the ear has been proposed. In healthy subjects, a prominent fMRI BOLD signal deactivation in the limbic system was found. The present pilot study investigates the effects of this novel technique of auricular transcutaneous electric nerve stimulation in depressed patients for the first time. A total of 37 patients suffering from major depression were included in two randomized sham controlled add-on studies. Patients were stimulated five times a week on a daily basis for the duration of 2 weeks. On days 0 and 14, the Hamilton Depression Rating Scale (HAMD) and the Beck Depression Inventory (BDI) were assessed. In contrast to sham-treated patients, electrically stimulated persons showed a significantly better outcome in the BDI. Mean decrease in the active treatment group was 12.6 (SD 6.0) points compared to 4.4 (SD 9.9) points in the sham group. HAMD score did not change significantly in the two groups. An antidepressant effect of a new transcutaneous auricular nerve stimulation technique has been shown for the first time in this controlled pilot study. Regarding the limitations of psychometric testing, the risk of unblinding for technical reasons, and the small sample size, further studies are necessary to confirm the present results and verify the practicability of tVNS in clinical fields.     

Effects of Bihemispheric Transcranial Direct Current Stimulation on Upper Extremity Function in Stroke Patients: A randomized Double-Blind Sham-Controlled Study

Background and PurposeTranscranial direct current stimulation (tDCS) is a treatment used in the rehabilitation of stroke patients aiming to improve functionality of the plegic upper extremity. Currently, tDCS is not routinely used in post stroke rehabilitation. The aim of this study was to establish the effects of bihemspheric tDCS combined with physical therapy (PT) and occupational therapy (OT) on upper extremity motor function.MethodsThirty-two stroke inpatients were randomised into 2 groups. All patients received 15 sessions of conventional upper extremity PT and OT over 3 weeks. The tDCS group (n = 16) also received 30 minutes of bihemispheric tDCS and the sham group (n = 16) 30 minutes of sham bihemispheric tDCS simultaneously to OT. Patients were evaluated before and after treatment using the Fugl Meyer upper extremity (FMUE), functional independence measure (FIM), and Brunnstrom stages of stroke recovery (BSSR) by a physiatrist blind to the treatment groupResultsThe improvement in FIM was higher in the tDCS group compared to the sham group (P = .001). There was a significant within group improvement in FMUE, FIM and BSSR in those receiving tDCS (P = .001). There was a significant improvement in FIM in the chronic (> 6months) stroke sufferers who received tDCS when compared to those who received sham tDCS and when compared to subacute stroke (3-6 months) sufferers who received tDCS/sham.ConclusionsUpper extremity motor function in hemiplegic stroke patients improves when bihemispheric tDCS is used alongside conventional PT and OT. The improvement in functionality is greater in chronic stroke patients.     

颅内前循环动脉瘤术中诱发电位监测效果评估

目的 探讨全静脉麻醉下经颅电刺激运动诱发电位(TES-MEPs)联合体感诱发电位(SEP)监测颅内前循环动脉瘤手术及预防缺血性卒中的应用价值.方法 47例颅内动脉瘤夹闭手术患者,术中行SEP和TES-MEPs联合监测,以神经功能检查作为评价指标,比较术前和术后神经功能的改变和诱发电位变化之间的关系.结果 43例神经功能未见显著改变,4例神经功能出现不同程度下降,其中3例MEP及SEP同时出现波幅下降＞50%或消失,且手术结束时未恢复至基线水平,与术后神经功能障碍发生具有一致性.结论 术中监测指标的改变可较早地获得脑缺血的证据,联合SEP与MEP监测有利于降低术后缺血性脑卒中的发生.     

经皮电刺激联合功能训练治疗卒中后吞咽功能障碍的疗效比较

目的本研究旨在探讨经皮神经电刺激（TENS）联合吞咽功能训练治疗急性期、恢复期脑卒中后吞咽功能障碍的疗效评价,对比急、慢性期患者治疗的效果差异;以及对比急性期患者TENS联合治疗与单纯吞咽功能训练的疗效差异。方法118例脑卒中后吞咽功能障碍的患者分为急性期治疗组和恢复期TENS联合功能训练治疗组（简称：恢复期联合治疗组）;其中急性期治疗组随机分为急性期TENS联合吞咽功能训练治疗组（简称：急性期联合治疗组）和急性期吞咽功能训练组（急性期功能训练组）两个亚组。三组均使用常规药物治疗和吞咽功能训练,除急性期吞咽功能训练组外其他两组在此基础上加用TENS治疗,疗程两周。在治疗前、治疗1周、治疗2周后采用吞咽x线电视透视检查吞咽功能进行评价。急性期联合治疗组、急性期吞咽功能训练组分别与恢复期联合治疗组比较;以及急性期两亚组间进行比较。结果治疗后2周急性期联合治疗组有效35例,有效率87．5％;急性期功能训练组有效32例,有效率82％;恢复期联合治疗组有效24例,有效率61．5％。急性期联合治疗组和急性期功能训练组均与恢复期联合治疗组比较,差异有统计学意义（P〈0．05）;但急性期两亚组间差异无统计学意义（P〉0．05）。结论脑卒中后吞咽功能障碍患者采用吞咽功能训练联合TENS治疗和单纯吞咽功能训练均有效改善脑卒中后的吞咽功能,急性期明显高于慢性期患者的疗效。但是急性期采用吞咽功能训练联合TENS与单纯吞咽功能训练的效果相当。     

Effect of median-nerve electrical stimulation on BOLD activity in acute ischemic stroke patients

Objective

To investigate blood oxygenation level-dependent (BOLD) activation during somatosensory electrical stimulation of the median nerve in acute stroke patients and to determine its correlation with ischemic damage and clinical recovery over time.

Methods

Fourteen acute stroke patients underwent functional magnetic resonance imaging (fMRI) during contralesional median-nerve electrical stimulation 12-48 h after stroke. Findings were then validated by diffusion tensor imaging (DTI) and motor evoked potential by transcranial magnetic stimulation (TMS).

Results

Poor clinical recovery at three months was noted in four patients with no activation in the early days after stroke, whereas good clinical recovery was observed in eight patients with a normal activation pattern in the primary sensory motor area in the acute phase. In two patients BOLD activation correlated weakly with clinical recovery. Findings from TMS and DTI partially correlated with clinical recovery and functional scores.

Conclusions

Clinically relevant insights into the “functional reserve” of stroke patients gained with peripheral nerve stimulation during fMRI may carry prognostic value already in the acute period of a cerebrovascular accident.

Significance

BOLD activation maps could provide insights into the functional organization of the residual systems and could contribute to medical decision making in neurological and rehabilitative treatment.