Beyond hyperglycemia: glycaemic variability as a prognostic factor after acute ischemic stroke

INTRODUCTION

Glycaemic variability (GV) refers to variations in blood glucose levels, and may affect stroke outcomes. This study aims to assess the effect of GV on acute ischaemic stroke progression.

METHODS

We performed an exploratory analysis of the multicentre, prospective, observational GLIAS-II study. Capillary glucose levels were measured every 4 hours during the first 48 hours after stroke, and GV was defined as the standard deviation of the mean glucose values. The primary outcomes were mortality and death or dependency at 3 months. Secondary outcomes were in-hospital complications, stroke recurrence, and the impact of the route of insulin administration on GV.

RESULTS

A total of 213 patients were included. Higher GV values were observed in patients who died (n = 16; 7.8%; 30.9 mg/dL vs 23.3 mg/dL; p = 0.05). In a logistic regression analysis adjusted for age and comorbidity, both GV (OR = 1.03; 95% CI, 1.003-1.06; p = 0.03) and stroke severity (OR = 1.12; 95% CI, 1.04-1.2; p = 0.004) were independently associated with mortality at 3 months. No association was found between GV and the other outcomes. Patients receiving subcutaneous insulin showed higher GV than those treated with intravenous insulin (38.95 mg/dL vs 21.34 mg/dL; p < 0.001).

CONCLUSIONS

High GV values during the first 48 hours after ischaemic stroke were independently associated with mortality. Subcutaneous insulin may be associated with higher VG levels than intravenous administration.

Strength of association of classical vascular risk factors in young patients with ischaemic stroke: a case-control study

INTRODUCTION

Recent studies have reported an increasing incidence of ischaemic stroke among young adults. However, the strength of the association between traditional vascular risk factors has not been fully established.

METHODS

We compared 120 patients with a first ischaemic stroke before the age of 55 years admitted to the stroke unit of our centre with 600 healthy non-stroke controls from a population-based cohort study (HERMEX), matched for sex. Risk factors assessed included: hypertension, obesity, auricular fibrillation, current smoking, estimated glomerular filtration rate (eGFR), total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglycerides, high-density lipoprotein cholesterol (HDL-C) and diabetes mellitus. We used logistic regression analysis and calculated population attributable risk. We performed an overall analysis, by sex and aetiological subgroup.

RESULTS

Using logistic regression analysis, we found that overall, the significant risk factors were: hypertension (OR: 1.58; 95%CI: 1.01-2.50), atrial fibrillation (OR: 4.77; 95%CI: 1.20-19.00), low eGFR (OR: 4.74; 95%CI: 1.3-21.94) and low HDL-C (OR: 5.20; 95%CI: 3.29-8.21), as well as smoking for males (OR: 1.86; 95%CI: 1.14-3.03). LDL-C showed an inverse association with stroke. The population attributable risk for HDL-C was 37.8% and for hypertension 21.1%. In terms of aetiological subgroups, only low HDL-C was associated with stroke of undetermined aetiology.

CONCLUSIONS

Hypertension, auricular fibrillation, low eGFR, and low HDL-C, plus tobacco use in men, are the main risk factors among patients under 55 years of age with a first ischaemic stroke. We believe that it would be of particular interest to further explore the management of low HDL-C levels as part of preventive strategies in young stroke patients.

Three-month functional prognosis of patients hospitalised due to acute ischaemic stroke in Aragon: regional analysis of the impact of COVID-19

Introduction

The COVID-19 pandemic has had an impact on ischaemic stroke management, with a reported decrease in hospital admissions, and even disruptions in healthcare and increased in-hospital mortality. However, there is a lack of evidence on the impact of the pandemic on functional prognosis. The aim of this study is to analyse the effect of the COVID-19 pandemic on the 3-month functional outcomes of patients hospitalised due to acute ischaemic stroke in Aragon (Spain).

Methods

We reviewed the data of all patients admitted due to ischaemic stroke to any hospital in our regional healthcare system between 30 December 2019 and 3 May 2020. We compared modified Rankin Scale scores and mortality at 3 months in patients hospitalised before and after the declaration of a state of emergency due to the COVID-19 pandemic.

Results

In total, 318 patients with acute ischaemic stroke met our inclusion criteria. No differences were observed between periods in global or specific characteristics, with the exception of a higher proportion of patients older than 80 years during the first period (42.2% vs 29.0%, P = .028). In the comparative analysis, we found no significant differences in mortality (12.3 vs 7.9, P = .465) or in the proportion of patients with modified Rankin Scale scores ≤ 2 (57.7% vs 57.1%, P = .425) at 3 months.

Conclusion

To our knowledge, this is the first study to analyse the impact of COVID-19 pandemic on the 3-month functional outcomes of patients with ischaemic stroke. In our region, there has been no increase in rates of mortality or disability at 3 months in patients admitted due to ischaemic stroke during the pandemic.

The role of left atrial enlargement and age in the prediction of recurrence in embolic strokes of undetermined source

Objectives

Left atrial disease is an independent risk factor for ischemic stroke and can be used to predict atrial fibrillation (AF). We examine whether left atrial enlargement (LAE) could predict stroke recurrence in patients with embolic stroke of undetermined source (ESUS).

Materials and methods

Sixty-four patients with a confirmed diagnosis of ESUS were followed for a median of 22 months. Clinical data and echocardiogram findings were recorded. The echocardiogram interpretation was performed centrally and blindly. The Brown ESUS - AF score was used to categorize patients into high (human resource planning [HRP]: score > 2) and low-risk patients (non-HRP score 0-1). Stroke recurrence was the primary outcome.

Results

The median age was 62 years (range: 22-85 years); and 33 (51.6%) were men. The median initial NIHSS score was three points (range: 0-27). Twelve (18.8%) patients were categorized as HRP. We found a significant tendency toward recurrence among HRP versus non-HRP patients. Three (25%) HRP versus 2 (3.8%) non-HRP experienced recurrence (OR: 8.3 95% CI 1.2-57; p=0.042); this association was related to severe atrial dilatation (OR: 14.5 95% CI 0.78-277, p = 0.02) and age > 75 years (OR: 12.7 95% CI 1.7-92.2, p = 0.03). We found no differences in recurrence in a univariate analysis.

Conclusions

Patients with severe LAE who are 75 years old or older have a significant tendency to experience stroke recurrence.

Beyond hyperglycemia: glycaemic variability as a prognostic factor after acute ischemic stroke

INTRODUCTION

Glycaemic variability (GV) refers to variations in blood glucose levels, and may affect stroke outcomes. This study aims to assess the effect of GV on acute ischaemic stroke progression.

METHODS

We performed an exploratory analysis of the multicentre, prospective, observational GLIAS-II study. Capillary glucose levels were measured every 4 hours during the first 48 hours after stroke, and GV was defined as the standard deviation of the mean glucose values. The primary outcomes were mortality and death or dependency at 3 months. Secondary outcomes were in-hospital complications, stroke recurrence, and the impact of the route of insulin administration on GV.

RESULTS

A total of 213 patients were included. Higher GV values were observed in patients who died (n = 16; 7.8%; 30.9 mg/dL vs 23.3 mg/dL; p = 0.05). In a logistic regression analysis adjusted for age and comorbidity, both GV (OR = 1.03; 95% CI, 1.003-1.06; p = 0.03) and stroke severity (OR = 1.12; 95% CI, 1.04-1.2; p = 0.004) were independently associated with mortality at 3 months. No association was found between GV and the other outcomes. Patients receiving subcutaneous insulin showed higher GV than those treated with intravenous insulin (38.95 mg/dL vs 21.34 mg/dL; p < 0.001).

CONCLUSIONS

High GV values during the first 48 hours after ischaemic stroke were independently associated with mortality. Subcutaneous insulin may be associated with higher VG levels than intravenous administration.

DNA and RNA oxidative damage are associated to mortality in patients with cerebral infarction

OBJECTIVE

Secondary injury due to oxidation may occur during ischemic stroke, possibly leading to oxidative damage to deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Higher blood concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) (through the oxidation of guanosine from DNA) have been found in ischemic stroke patients than in healthy subjects, and in patients with versus without post-ischemic stroke depression. The present study was carried out to explore the possible association between serum DNA and RNA oxidative damage and mortality in patients with cerebral infarction.

METHODS

A prospective, multicenter observational study was carried out in the Intensive Care Units of 6 Spanish hospitals. We included patients with severe malignant middle cerebral artery infarction (MMCAI) defined as ischemic changes evidenced by computed tomography in more than 50% of the middle cerebral artery territory and a Glasgow Coma Score (GCS)<9. Serum concentrations of the three oxidized guanine species (OGS) (8-hydroxyguanine from DNA or RNA, 8-hydroxyguanosine from RNA, and 8-OHdG from DNA) on the day of MMCAI diagnosis were determined. The study endpoint was 30-day mortality.

RESULTS

We found higher serum OGS levels (p<0.001) in non-surviving (n=34) than in surviving patients (n=34). Logistic regression analyses showed serum OGS levels to be associated to 30-day mortality controlling for lactic acid, GCS and platelet count (OR=1.568; 95%CI=1.131-2.174; p=0.01).

CONCLUSIONS

The novel observation in this study is the association between global serum OGS concentration and mortality in ischemic stroke patients.

Cognitive profile of children with sickle cell anemia compared to healthy controls

OBJECTIVE

To evaluate the cognitive abilities of children and adolescents with sickle cell anemia diagnosed through neonatal screening and to compare them with healthy controls, adjusting the results to their socioeconomic status.

METHODS

Cognitive assessment was performed with the Wechsler WISC-III scale in 64 children and adolescents with sickle cell anemia and in 64 controls matched by gender and age, without the disease and without neurological impairment; socioeconomic status was measured by the Criterion Brasil.

RESULTS

All cognitive scores were lower in the group of patients. The mean overall IQ, Verbal IQ, and Performance IQ were, respectively, 90.95 for the group of patients and 113.97 for the controls (p<0.001); 91.41 for the group of patients and 112.31 for the controls (p<0.001); 92.34 for the group of patients and 113.38 for the controls (p<0.001). Scores for processing speed, distraction resistance, and perceptual organization were also significantly lower in patients. A direct and significant correlation was detected between socioeconomic status and cognitive scores. In the multivariate analysis, for the same socioeconomic status, a child with sickle cell anemia had an average IQ of 21.2 points lower than the mean IQ observed for the controls (p<0.001), indicating that the disease, adjusted for the socioeconomic effect, is a strong predictor of the overall IQ.

CONCLUSION

The cognitive impairment of children with sickle cell anemia is severe and manifests even when the disease effect is adjusted to the socioeconomic status. In the authors' view, such impairment requires an early preventive approach in order to avoid this cognitive damage.

[Polimorfismos asociados a disfunción endotelial y a un estado protrombótico en jóvenes mexicanos con infarto cerebral]

Objective

To examine the contribution the polymorphisms G20210A, G1691A and G10976A in the coagulation factors FII, FV, FVII, respectively; Glu298Asp and C677T in eNOS and 5,10 MTHFR in young Mexican population with cerebral infarction (CI).

Methods

224 patients ≤ 45 years of age with CI and 224 controls matched by age and gender were recruited from 2006 and 2014. The polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism.

Results

We identified a significant difference in the genotype distribution of Glu298Asp (p = 0.001) and C677T (p = 0.01) polymorphisms between CI patients and control groups. The genotype distribution in the FII G20210A, FV G1691A and FVII G10976A polymorphisms were similar. There were independent factors for ischemic stroke: Glu298Asp and C677T polymorphisms, smoking; hypertension, and familial history of thrombotic disease.

Conclusions

The Glu298Asp and C677T, but not FII G20210A, FV G1691A and FVII G10976A polymorphisms were associated with CI. Our results suggest that endothelial dysfunction and the synergist interaction with other factors such as smoking and hypertension contribute to CI in young individuals.

The importance of bilateral monitoring of cerebral oxygenation (NIRS): Clinical case of asymmetry during cardiopulmonary bypass secondary to previous cerebral infarction

Cerebral oximetry based on near infrared spectroscopy (NIRS) technology is used to determine cerebral tissue oxygenation. We hereby present the clinical case of a 12-month old child with right hemiparesis secondary to prior left middle cerebral artery stroke 8 months ago. The child underwent surgical enlargement of the right ventricular outflow tract (RVOT) with cardiopulmonary bypass. During cardiopulmonary bypass, asymmetric NIRS results were detected between both hemispheres. The utilization of multimodal neuromonitoring (NIRS-BIS) allowed acting on both perfusion pressure and anesthetic depth to balance out the supply and demand of cerebral oxygen consumption. No new neurological sequelae were observed postoperatively. We consider bilateral NIRS monitoring necessary in order to detect asymmetries between cerebral hemispheres. Although asymmetries were not present at baseline, they can arise intraoperatively and its monitoring thus allows the detection and treatment of cerebral ischemia-hypoxia in the healthy hemisphere, which if undetected and untreated would lead to additional neurological damage.

Stroke in young adults: Incidence rate, risk factors, treatment and prognosis

OBJECTIVES

To analyse the incidence, risk factors, aetiology, treatment and clinical evolution of young patients with stroke.

PATIENTS AND METHODS

Retrospective registry of patients aged 55 years or younger hospitalised in a stroke unit during 2014. We recorded the incidence rate for all strokes and analysed demographic data, risk factors, degree of stress, stroke type and aetiology, reperfusion treatments and clinical evolution.

RESULTS

The study included 110 patients, the majority of whom were men (60.9%, 1.6:1 ratio). The incidence rate was 13.3% (110 of 830 strokes). Most of the patients had cardiovascular risk factors. Smoking was the most common risk factor (56.4%), followed by arterial hypertension (50%), dyslipidaemia (42.7%), obesity (33%), diabetes (18.2%) and emboligenic heart disease (12.7%). Some 64.3% of the heart disease cases and 51.1% of the dyslipidaemia cases were discovered during hospitalisation. Some 57.2% of the patients experienced psychosocial stress in the stage prior to the stroke. Some 83.6% of the stroke cases were ischaemic, 12.7% were haemorrhagic and 3.6% were venous sinus thrombosis. Of the ischaemic stroke cases, 30.4% were cryptogenic, 23.9% were lacunar, 16.3% were from uncommon causes, 15.2% were atherothrombotic and 14.1% were cardioembolic. Some 78.6% of the cerebral haemorrhage cases were hypertensive. Some 23.3% of the ischaemic stroke cases underwent reperfusion treatments in the acute phase, achieving levels of functional independence at 3 months of 62.5%.

CONCLUSIONS

The majority of stroke events in patients 55 years of age or younger appear to be related to a high prevalence of classical cardiovascular risk factors and possibly to psychosocial stress.

[Stroke in young adults: incidence and clinical picture in 280 patients according to their aetiological subtype]

BACKGROUND AND OBJECTIVE

To assess the clinical features and incidence rate of stroke in young adults (less than 55 years of age).

METHODS

Hospital-based descriptive study of 280 young inpatients consecutively admitted for stroke over a period of 24 years. We conducted a comparison with the remaining 4,312 patients admitted for stroke.

RESULTS

Stroke in young adults represented 6.1% of all strokes, 5.7% of transient ischaemic attacks, 5.8% of cerebral infarctions and 8.4% of brain haemorrhages. However, reported minimal frequency of cardioembolic (2.1%) and atherothrombotic (3.4%) infarctions, accounted for 5.9% of lacunar and for 10.7% of essential infarctions and showed a maximum frequency in those infarctions of unusual aetiology (36%). Factors independently associated with stroke in young adults were cigarette smoking (OR 4.23; 95% CI 3.02-5.93; P=.000), unusual aetiology (OR 4.97; 95% CI 3.15-7.84; P=.000), headache (OR 4.57; 95% CI 2.59-8.07; P=.000), alcohol abuse (OR 3.93; 95% CI 2.46-6.29; P=.000), oral contraceptives (OR 14.07; 95% CI 2.37-83.40; P=.004), atrial fibrillation (OR 0.15; 95% CI 0.08-0.28; P=.000), arterial hypertension (OR 0.43; 95% CI 0.33-0.57; P=.000), COPD (OR 0.20; 95% CI 0.09-0.44; P=.000), atherothrombotic infarction (OR 0.51; 95% CI 0.34-0.77; P=.001), female sex (OR 0.71; 95% CI 0.52-0.97; P=.029), diabetes mellitus (OR 0.66; 95% CI 0.46-0.98; P=.030), ischaemic heart disease (OR 0.56; 95% CI 0.33-0.95; P=.032) and intermittent claudication (OR 0.48; 95% CI 0.24-0.94; P=.033).

CONCLUSIONS

Stroke in young adults is infrequent (6.1% of the total), but represents the highest frequency of cerebral infarcts of unusual aetiology (36%). We conclude that stroke in younger patients presents its own and differentiated clinical profile.

Rapid diagnosis and treatment of TIA results in low rates of stroke, myocardial infarction and vascular death

INTRODUCTION

The 90-day risk of cerebral infarction in patients with transient ischaemic attack (TIA) is estimated at between 8% and 20%. There is little consensus as to which diagnostic strategy is most effective. This study evaluates the benefits of early transthoracic echocardiography (TTE) with carotid and transcranial Doppler ultrasound in patients with TIA.

METHODS

Prospective study of patients with TIA in an emergency department setting. Demographic data, vascular risk factors, and ABCD(2) score were analysed. TIA aetiology was classified according to TOAST criteria. All patients underwent early vascular studies (<72hours), including TTE, carotid ultrasound, and transcranial Doppler. Primary endpoints were recurrence of stroke or TIA, myocardial infarction (MI), or vascular death during the first year.

RESULTS

We evaluated 92 patients enrolled over 24 months. Mean age was 68.3±13 years and 61% were male. The mean ABCD(2) score was 3 points (≥5 in 30%). The distribution of TIA subtypes was as follows: 12% large-artery atherosclerosis; 30% cardioembolism; 10% small-vessel occlusion; 40% undetermined cause; and 8% rare causes. Findings from the early TTE led to a change in treatment strategy in 6 patients (6.5%) who displayed normal physical examination and ECG findings. At one year of follow-up, 3 patients had experienced stroke (3.2%) and 1 patient experienced MI (1%); no vascular deaths were identified.

CONCLUSIONS

In our TIA patients, early vascular study and detecting patients with silent cardiomyopathy may have contributed to the low rate of vascular disease recurrence.

[Vascular assessment in stroke codes: role of computed tomography angiography]

Advances in imaging studies for acute ischemic stroke are largely due to the development of new efficacious treatments carried out in the acute phase. Together with computed tomography (CT) perfusion studies, CT angiography facilitates the selection of patients who are likely to benefit from appropriate early treatment. CT angiography plays an important role in the workup for acute ischemic stroke because it makes it possible to confirm vascular occlusion, assess the collateral circulation, and obtain an arterial map that is very useful for planning endovascular treatment. In this review about CT angiography, we discuss the main technical characteristics, emphasizing the usefulness of the technique in making the right diagnosis and improving treatment strategies.

Intra-procedural imaging of the left atrial appendage: implications for closure with the Amplatzer™ cardiac plug

OBJECTIVES

To evaluate intra-procedural imaging with transesophageal echocardiography and angiography during left atrial appendage occlusion using the Amplatzer™ Cardiac Plug with regard to sizing and final device shape.

METHODS

Left atrial appendage ostium dimensions and diameter at a depth of 10mm from the ostium were measured by transesophageal echocardiography (0-180°) and angiography (RAO 30° - Cranial 20°) in consecutive patients undergoing left atrial appendage occlusion using the ACP with an oversizing strategy of 10-20% relative to the baseline measurements. After delivery, ACP dimensions were measured and device shape was assessed.

RESULTS

Twenty-seven consecutive patients underwent successful uncomplicated left atrial appendage closure with Amplatzer™ Cardiac Plug. We found a significant difference between the largest and smallest left atrial appendage diameter measured with transesophageal echocardiography (22.3±4.2 vs. 18.1±4.1mm, p<0.001). By the end of the procedure (by angiography), ACP had an optimal shape in 17 patients (63%), a strawberry-like shape in 7 patients (26%), and a square-like shape in 3 patients (11%). ACP was oversized on average by 1.5±2.7 and 3.3±2.3mm compared to transesophageal echocardiography and angiography, respectively. The final shape of the device was not significantly associated with the degree of oversizing.

CONCLUSIONS

We found a considerable variability in the assessment of the left atrial appendage, using transesophageal echocardiography and angiography. The degree of Amplatzer™ Cardiac Plug expansion within the left atrial appendage and the final shape of the device were not associated with the degree of oversizing.

Malignant hemispheric infarction of the middle cerebral artery. Diagnostic considerations and treatment options

INTRODUCTION

Malignant hemispheric infarction (MHI) is a specific and devastating type of ischemic stroke. It usually affects all or part of the territory of the middle cerebral artery although its effects may extend to other territories as well. Its clinical outcome is frequently catastrophic when only conventional medical treatment is applied.

OBJECTIVE

The purpose of this review is to analyse the available scientific evidence on the treatment of this entity.

DEVELOPMENT

MHI is associated with high morbidity and mortality. Its clinical characteristics are early neurological deterioration and severe hemispheric syndrome. Its hallmark is the development of space-occupying cerebral oedema between day 1 and day 3 after symptom onset. The mass effect causes displacement, distortion, and herniation of brain structures even when intracranial hypertension is initially absent. Until recently, MHI was thought to be fatal and untreatable because mortality rates with conventional medical treatment could exceed 80%. In this unfavourable context, decompressive hemicraniectomy has re-emerged as a therapeutic alternative for selected cases, with reported decreases in mortality ranging between 15% and 40%.

CONCLUSIONS

In recent years, several randomised clinical trials have demonstrated the benefit of decompressive hemicraniectomy in patients with MHI. This treatment reduces mortality in addition to improving functional outcomes.

Carotid artery stenting: clinical and procedural implications for near-occlusion stenosis

INTRODUCTION AND OBJECTIVES

The advisability of implanting a stent in carotid near-occlusion stenosis is a controversial topic. We have assessed procedural and clinical implications of stent implantation for carotid artery disease with near occlusion.

METHODS

We included 205 patients who underwent carotid artery revascularisation with a stent. The group of patients with near-occlusion stenosis (n=54)was compared to the rest of the population (n=151).

RESULTS

No differences were found between groups for age, sex, and the percentage of symptomatic patients (three-quarters of the population). Carotid stent revascularisation for near-occlusion stenosis presented a high procedural success rate (96%) similar to that of revascularisation processes for other lesions (98%). Stenting in cases of near-occlusion stenosis required increased use of proximal protection (54% vs. 20.5%, P<.001) and predilation (33% vs. 17%, P=.01). The process to repair near-occlusion stenosis cause increased detachment of plaque, as shown by higher percentages of macroscopic plaque captured by protection devices (18.5% vs. 7%, P=.01) and of perioperative ischaemic brain lesions (47% vs 31%, P = .07). At 30 days of follow-up, the tendency toward adverse neurological events (death, major and minor stroke) was higher in the near-occlusion group (9.2% vs. 3.2%, P=.08).

CONCLUSIONS

Stent revascularisation for near-occlusion carotid stenosis has a high procedural success rate; however, its higher plaque load was responsible for the increased rate of ischaemic brain lesions and adverse neurovascular events at 30 days post-procedure.

Guidelines for the treatment of acute ischaemic stroke

INTRODUCTION

Update of Acute Ischaemic Stroke Treatment Guidelines of the Spanish Neurological Society based on a critical review of the literature. Recommendations are made based on levels of evidence from published data and studies.

DEVELOPMENT

Organized systems of care should be implemented to ensure access to the optimal management of all acute stroke patients in stroke units. Standard of care should include treatment of blood pressure (should only be treated if values are over 185/105 mmHg), treatment of hyperglycaemia over 155 mg/dl, and treatment of body temperature with antipyretic drugs if it rises above 37.5 °C. Neurological and systemic complications must be prevented and promptly treated. Decompressive hemicraniectomy should be considered in cases of malignant cerebral oedema. Intravenous thrombolysis with rtPA should be administered within 4.5 hours from symptom onset, except when there are contraindications. Intra-arterial pharmacological thrombolysis can be considered within 6 hours, and mechanical thrombectomy within 8 hours from onset, for anterior circulation strokes, while a wider window of opportunity up to 12-24 hours is feasible for posterior strokes. There is not enough evidence to recommend routine use of the so called neuroprotective drugs. Anticoagulation should be administered to patients with cerebral vein thrombosis. Rehabilitation should be started as early as possible.

CONCLUSION

Treatment of acute ischaemic stroke includes management of patients in stroke units. Systemic thrombolysis should be considered within 4.5 hours from symptom onset. Intra-arterial approaches with a wider window of opportunity can be an option in certain cases. Protective and restorative therapies are being investigated.