Neurological recovery after decompressive craniectomy for massive ischemic stroke

Role of decompressive craniectomy in the management of acute ischemic stroke (Review)

The application of decompressive craniectomy (DC) is thoroughly documented in the management of brain edema, particularly following traumatic brain injury. However, an increasing amount of concern is developing among the universal medical community as regards the application of DC in the treatment of other causes of brain edema, such as subarachnoid hemorrhage, cerebral hemorrhage, sinus thrombosis and encephalitis. Managing stroke continues to remain challenging, and demands the aggressive and intensive consulting of a number of medical specialties. Middle cerebral artery (MCA) infarcts, which consist of 1-10% of all supratentorial infarcts, are often associated with mass effects, and high mortality and morbidity rates. Over the past three decades, a number of neurosurgical medical centers have reported their experience with the application of DC in the treatment of malignant MCA infarction with varying results. In addition, over the past decade, major efforts have been dedicated to multicenter randomized clinical trials. The present study reviews the pertinent literature to outline the use of DC in the management of malignant MCA infarction. The PubMed database was systematically searched for the following terms: 'Malignant cerebral infarction', 'surgery for stroke', 'DC for cerebral infarction', and all their combinations. Case reports were excluded from the review. The articles were categorized into a number of groups; the majority of these were human clinical studies, with a few animal experimental clinical studies. The surgical technique involved was DC, or hemicraniectomy. Other aspects that were included in the selection of articles were methodological characteristics and the number of patients. The multicenter randomized trials were promising. The mortality rate has unanimously decreased. As for the functional outcome, different scales were employed; the Glasgow Outcome Scale Extended was not sufficient; the Modified Rankin Scale and Bathel index, as well as other scales, were applied. Other aspects considered were demographics, statistics and the very interesting radiological ones. There is no doubt that DC decreases mortality rates, as shown in all clinical trials. Functional outcome appears to be the goal standard in modern-era neurosurgery, and quality of life should be further discussed among the medical community and with patient consent.

Compensation of Ipsilateral Motor and Sensory Functions by Contralateral Uncrossed Pathway in a Stroke Patient With Half Brain

ABSTRACT

This study reports a case of motor and sensory function recovery after massive left cerebral infarction in a young man, along with preserved function of the injured hemisphere. He received early rehabilitation therapy in a nerval care unit within 1 wk of surgery, and the rehabilitation lasted for more than 3 yrs. When he gradually recovered from coma, his motor, sensory, and speech functions improved significantly. Two years later, he was able to live independently and returned to work. The findings of functional magnetic resonance imaging, diffusion tensor imaging, somatosensory evoked potential, and motor evoked potential confirmed that there was a strong connection between his right brain and the right limbs. Thus, early rehabilitation is a promising approach for restoring motor and sensory function after massive brain injury or extensive brain tissue damage.

Epidural Oscillating Cardiac-Gated Intracranial Implant Modulates Cerebral Blood Flow

BACKGROUND

We have previously reported a method and device capable of manipulating ICP pulsatility while minimally effecting mean ICP.

OBJECTIVE

To test the hypothesis that different modulations of the intracranial pressure (ICP) pulse waveform will have a differential effect on cerebral blood flow (CBF).

METHODS

Using an epidural balloon catheter attached to a cardiac-gated oscillating pump, 13 canine subjects underwent ICP waveform manipulation comparing different sequences of oscillation in successive animals. The epidural balloon was implanted unilaterally superior to the Sylvian sulcus. Subjects underwent ICP pulse augmentation, reduction and inversion protocols, directly comparing time segments of system activation and deactivation. ICP and CBF were measured bilaterally along with systemic pressure and heart rate. CBF was measured using both thermal diffusion, and laser doppler probes.

RESULTS

The activation of the cardiac-gate balloon implant resulted in an ipsilateral/contralateral ICP pulse amplitude increase with augmentation (217%/202% respectively, P < .0005) and inversion (139%/120%, P < .0005). The observed changes associated with the ICP mean values were smaller, increasing with augmentation (23%/31%, P < .0001) while decreasing with inversion (7%/11%, P = .006/.0003) and reduction (4%/5%, P < .0005). CBF increase was observed for both inversion and reduction protocols (28%/7.4%, P < .0001/P = .006 and 2.4%/1.3%, P < .0001/P = .003), but not the augmentation protocol. The change in CBF was correlated with ICP pulse amplitude and systolic peak changes and not with change in mean ICP or systemic variables (heart rate, arterial blood pressure).

CONCLUSION

Cardiac-gated manipulation of ICP pulsatility allows the study of intracranial pulsatile dynamics and provides a potential means of altering CBF.

Second-look strokectomy of cerebral infarction areas in patients with severe herniation

OBJECTIVE

Decompressive craniectomies (DCs) are performed on patients suffering large cerebral infarctions. The efficacy of this procedure has been demonstrated in several trials. In some cases, however, this procedure alone is not sufficient and patients still suffer refractory elevations of intracranial pressure (ICP). The goal of this study was to determine whether resection of infarcted tissue, termed strokectomy, performed as a second-look procedure after DC, improves outcome in selected cases.

METHODS

The authors retrospectively evaluated data of patients who underwent a DC due to a cerebral infarction at their institution from 2009 to 2016, including patients who underwent a strokectomy procedure after DC. Clinical records, imaging data, outcome scores, and neurological symptoms were analyzed, and clinical outcomes and mortality rates in the strokectomy group were compared to those for similar patients in recently published randomized controlled trials.

RESULTS

Of 198 patients who underwent DC due to cerebral infarction, 12 patients underwent strokectomy as a second surgical procedure, with a median National Institutes of Health Stroke Scale (NIHSS) score of 19 for patients with versus 16 for those without secondary strokectomy (p = 0.029). Either refractory increases of ICP > 20 mm Hg or dilated pupils in addition to herniation visible on CT images were triggers for strokectomy surgery. Ten of 12 (83%) patients had infarctions in more than one territory (p < 0.001). After 12 months, 43% of patients had a good outcome according to the modified Rankin Scale (mRS) score (≤ 3). In the subgroup of patients suffering infarctions in more than one vascular territory, functional outcome after 12 months was better (mRS ≤ 3 in 40% of patients in comparison to 9%; p = 0.027). A 1:3 case-control analysis matched to age, side of infarction, sex, and vascular territory confirmed these results (mRS ≤ 3, 42% in comparison to 11%; p = 0.032). Age, NIHSS score on admission, and number of vascular territories involved were identified as risk factors in multivariate analysis (p < 0.05). Patients in the strokectomy group had more infections (p < 0.001). According to these results, the authors developed a scale (Münster Stroke Score, 0-6 points) to predict whether patients might benefit from additional strokectomy. Receiver-operating characteristic (ROC) curve analysis revealed an area under the curve (AUC) of 0.86 (p < 0.001). The authors recommend a Münster Stroke Score of ≥ 3 as a cutoff, with a sensitivity of 92% and specificity of 66%, for predicting benefit from strokectomy.

CONCLUSIONS

In this study in comparison to former studies, mortality rates were lower and clinical outcome was comparable to that of previously published trials regarding large cerebral infarctions. Second surgery including strokectomy may help achieve better outcomes, especially in cases of infarction of more than one vascular territory.

Quantitative sodium MR imaging: A review of its evolving role in medicine

Sodium magnetic resonance (MR) imaging in humans has promised metabolic information that can improve medical management in important diseases. This technology has yet to find a role in clinical practice, lagging proton MR imaging by decades. This review covers the literature that demonstrates that this delay is explained by initial challenges of low sensitivity at low magnetic fields and the limited performance of gradients and electronics available in the 1980s. These constraints were removed by the introduction of 3T and now ultrahigh (≥7T) magnetic field scanners with superior gradients and electronics for proton MR imaging. New projection pulse sequence designs have greatly improved sodium acquisition efficiency. The increased field strength has provided the expected increased sensitivity to achieve resolutions acceptable for metabolic interpretation even in small target tissues. Consistency of quantification of the sodium MR image to provide metabolic parametric maps has been demonstrated by several different pulse sequences and calibration procedures. The vital roles of sodium ion in membrane transport and the extracellular matrix will be reviewed to indicate the broad opportunities that now exist for clinical sodium MR imaging. The final challenge is for the technology to be supplied on clinical ≥3T scanners.

Stroke in Frail Older People

The population is ageing, with the greatest proportional increase in those >80 years of age. Many of these people will be frail and at risk of stroke. Research has shown that the very old have much to benefit from hyperacute stroke intervention, but at the same time they suffer increased mortality. Their outcome following stroke and intervention is more often predicted by the presence of frailty rather than age alone. Intervention both in primary prevention and hyperacute stroke management needs to allow for preexisting morbidity and frailty in deciding what is and what is not appropriate, rather than an arbitrary decision on age. Frail older people are more likely to develop delirium and dysphagia combined with poor mouthcare and die, yet all of these issues are managed badly. An increased awareness of these complications of stroke in the frail older person is necessary.

Validation of an International Classification of Disease, Ninth Revision coding algorithm to identify decompressive craniectomy for stroke

Background

Although International Classification of Disease, Ninth Revision, Clinical Modification (ICD9-CM) coding is the basis of administrative claims data, no study has validated an ICD9-CM algorithm to identify patients undergoing decompressive craniectomy for space-occupying supratentorial infarction.

Methods

Patients who underwent decompressive craniectomy for stroke at our institution were retrospectively identified and their associated ICD9-CM codes were extracted from billing data. An ICD9-CM algorithm was generated and its accuracy compared against physician review.

Results

A total of 10,925 neurosurgical operations were performed from December 2008 to March 2015, of which 46 (0.4%) were decompressive craniectomy for space-occupying stroke. The ICD9-CM procedure code for craniectomy (01.25) was only encoded in 67.4% of patients, while craniotomy (01.24) was used in 19.6% and lobectomy (01.39, 01.53, 01.59) in 13.1%. The ICD-9-CM algorithm included patients with a diagnosis codes for cerebral infarction (433.11, 434.01, 434.11, and 434.91) and a procedure code for craniotomy, craniectomy, or lobectomy. Patients were excluded with an ICD9-CM diagnosis code for brain tumor, intracranial abscess, subarachnoid hemorrhage, vertebrobasilar infarction, intracranial aneurysm, Moyamoya disease, intracranial venous sinus thrombosis, vertebral artery dissection, congenital cerebrovascular anomaly, head trauma or an ICD9-CM procedure code for laminectomy. This algorithm had a sensitivity of 97.8%, specificity of 99.9%, positive predictive value of 88.2%, and negative predictive value of 99.9%. The majority of false-positive results were patients who underwent evacuation of a primary intracerebral hematoma.

Conclusion

An ICD-9-CM algorithm based on diagnosis and procedure codes can effectively identify patients undergoing decompressive craniectomy for supratentorial stroke.

Functional Outcome After Decompressive Craniectomy in Patients with Dominant or Non-Dominant Malignant Middle Cerebral Infarcts

BACKGROUND

 The use of decompressive craniectomy (DC) has been studied in the setting of different conditions, including traumatic brain injury, subarachnoid hemorrhage, and malignant middle cerebral artery (MCA) infarction. The rationale of this study is to determine the functional outcome after DC in patients with malignant MCA infarcts.

METHODS

 A longitudinal cohort study was performed based on patients diagnosed with malignant MCA territory infarction admitted to the Neurosurgery Department of a tertiary care hospital in Islamabad, Pakistan between July 2015 and November 2016. All patients had a clinical diagnosis of stroke according to the World Health Organization (WHO) stroke criteria.

RESULTS

 A total of 34 patients participated in this study, out of which 20/31 (64.5%) were males while 11/31 (35.5%) were females with a mean age of 51.61 ± 13.96 years. The mean time from diagnosis to surgery was 60.61 ± 49.83 hours. Out of 31 patients, 18 (58.1%) had a right middle cerebral artery infarct (RMCAI) and 13 (41.9%) had a left middle cerebral artery infarct (LCAI). Logistic regression was applied to assess the association between the type of MCA infarct with the National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), modified Barthel Index (mBI) scores, and upper and lower limb motor power. However, the logistic regression model was not statistically significant χ² (4) = 3.896, p = 0.866. There was a statistically significant mild improvement of neurological scores and upper and lower motor power over a course of six months, but the overall functional outcome was poor with mBI < 60 and mRS > 4 (p < 0.001) with total mortality of 8.7%.

CONCLUSION

 Decompressive craniectomy is a life-saving surgery that appears to benefit patients with malignant MCA infarcts of either the dominant or non-dominant cerebral hemisphere. Decompressive craniectomy results in mild improvements in neurological scores but still poor functional outcome after six months.

Decompressive Hemicraniectomy for Stroke in Older Adults: A Review

Malignant cerebral edema is a potential consequence of large territory cerebral infarction, as the resultant elevation in intracranial pressure may progress to transtentorial herniation, brainstem compression, and death. In appropriate patients, decompressive hemicraniectomy (DHC) reduces mortality without increasing the risk of severe disability. However, as the foundational DHC randomized, controlled trials excluded patients greater than 60 years of age, the appropriateness of DHC in older adults remains controversial. Recent clinical trials among elderly participants, including DESTINY II, reported that DHC reduces mortality, but may leave patients with substantial morbidity. Nationwide analyses have demonstrated generalizability of such data. However, what constitutes an acceptable outcome - the perspective on quality of life after survival with substantial disability - varies between clinicians, patients, and caregivers. Consequently, quality of life measures are being increasingly incorporated into stroke research. This review summarizes the impact of DHC in space-occupying cerebral infarction, and the influence of patient age on postoperative survival, functional capacity, and quality of life-all key factors in the clinical decision process. Ultimately, these data underscore the inherent complexity in balancing scientific evidence, clinical expertise, and patient and family preference when pursuing hemicraniectomy among the elderly.

Decompressive craniectomy for malignant middle cerebral artery infarction: Impact on mortality and functional outcome

Background:

Malignant middle cerebral artery (MCA) infarction is a devastating clinical entity affecting about 10% of stroke patients. Decompressive craniectomy has been found to reduce mortality rates and improve outcome in patients.

Methods:

A retrospective case review study was conducted to compare patients treated with medical therapy and decompressive surgery for malignant MCA infarction in Hospital Kuala Lumpur over a period of 5 years (from January 2007 to December 2012). A total of 125 patients were included in this study; 90 (72%) patients were treated with surgery, while 35 (28%) patients were treated with medical therapy. Outcome was assessed in terms of mortality rate at 30 days, Glasgow Outcome Score (GOS) on discharge, and modified Rankin scale (mRS) at 3 and 6 months.

Results:

Decompressive craniectomy resulted in a significant reduction in mortality rate at 30 days (P < 0.05) and favorable GOS outcome at discharge (P < 0.05). Good functional outcome based on mRS was seen in 48.9% of patients at 3 months and in 64.4% of patients at 6 months (P < 0.05). Factors associated with good outcome include infarct volume of less than 250 ml, midline shift of less than 10 mm, absence of additional vascular territory involvement, good preoperative Glasgow Coma Scale (GCS) score, and early surgical intervention (within 24 h) (P < 0.05). Age and dominant hemisphere infarction had no significant association with functional outcome.

Conclusion:

Decompressive craniectomy achieves good functional outcome in, young patients with good preoperative GCS score and favorable radiological findings treated with surgery within 24 h of ictus.

Clinical application of perfusion computed tomography in neurosurgery

OBJECT

Currently, perfusion CT (PCT) is a valuable imaging technique that has been successfully applied to the clinical management of patients with ischemic stroke and aneurysmal subarachnoid hemorrhage (SAH). However, recent literature and the authors' experience have shown that PCT has many more important clinical applications in a variety of neurosurgical conditions. Therefore, the authors share their experiences of its application in various diseases of the cerebrovascular, neurotraumatology, and neurooncology fields and review the pertinent literature regarding expanding PCT applications for neurosurgical conditions, including pitfalls and future developments.

METHODS

A pertinent literature search was conducted of English-language articles describing original research, case series, and case reports from 1990 to 2011 involving PCT and with relevance and applicability to neurosurgical disorders.

RESULTS

In the cerebrovascular field, PCT is already in use as a diagnostic tool for patients suspected of having an ischemic stroke. Perfusion CT can be used to identify and define the extent of the infarct core and ischemic penumbra core, and thus aid patient selection for acute reperfusion therapy. For patients with aneurysmal SAH, PCT provides assessment of early brain injury, cerebral ischemia, and infarction, in addition to vasospasm. It may also be used to aid case selection for aggressive treatment of patients with poor SAH grade. In terms of oncological applications, PCT can be used as an imaging biomarker to assess angiogenesis and response to antiangiogenetic treatments, differentiate between glioma grades, and distinguish recurrent tumor from radiation necrosis. In the setting of traumatic brain injury, PCT can detect and delineate contusions at an early stage. In patients with mild head injury, PCT results have been shown to correlate with the severity and duration of postconcussion syndrome. In patients with moderate or severe head injury, PCT results have been shown to correlate with patients' functional outcome.

CONCLUSIONS

Perfusion CT provides quantitative and qualitative data that can add diagnostic and prognostic value in a number of neurosurgical disorders, and also help with clinical decision making. With emerging new technical developments in PCT, such as characterization of blood-brain barrier permeability and whole-brain PCT, this technique is expected to provide more and more insight into the pathophysiology of many neurosurgical conditions.

Decompressive craniectomy – friend or foe?

Decompressive craniectomy (DC) is the surgical management removing part of the skull vault over a swollen brain used to treat elevated intracranial pressure that is unresponsive to maximal medical therapy. The commonest indication for DC is traumatic brain injury (TBI) or middle cerebral artery (MCA) infarction, though DC has been reported to have been used for treatment of aneurysmal subarachnoid haemorrhage and venous infarction. Despite an increasing number of reports supportive of DC, the controversy over the suitability of the procedure and criteria for patient selection remains unresolved. Although the majority of published studies are retrospective, the recent publication of several randomised prospective studies prompts a re-evaluation of the use of DC. We review the literature concerning the pathophysiology, indication, surgical techniques and timing, complications and long-term effects of DC (including reversal with cranioplasty), in order to rationalise its use. We conclude that at the time of this review, though we cannot support the routine use of DC in TBI or MCA stroke, there is evidence that early and aggressive use of DC in TBI patients with intracranial haematomas or younger malignant MCA stroke patients may improve outcome. Though the results of the DECRA trial suggest that primary DC may worsen outcome, the decision to perform DC after diffuse TBI is still individualised. We await the results of the RESCUEicp trial to ascertain whether an evidence-based protocol for its use can be agreed in the future.

Decompressive craniectomy: technical note

Decompressive craniectomy is a neurosurgical technique in which a portion of the skull is removed to reduce intracranial pressure. The rationale for this procedure is based on the Monro-Kellie Doctrine; expanding the physical space confining edematous brain tissue after traumatic brain injury will reduce intracranial pressure. There is significant debate over the efficacy of decompressive craniectomy despite its sound rationale and historical significance. Considerable variation in the employment of decompressive craniectomy, particularly for secondary brain injury, explains the inconsistent results and mixed opinions of this potentially valuable technique. One way to address these concerns is to establish a consistent methodology for performing decompressive craniectomies. The purpose of this paper is to begin accomplishing this goal and to emphasize the critical points of the hemicraniectomy and bicoronal (Kjellberg type) craniectomy.

Assessment of outcome following decompressive craniectomy for malignant middle cerebral artery infarction in patients older than 60 years of age

Object

Decompressive surgery can be life saving after malignant cerebral infarction. However, severe residual disability occurs in a significant number of surviving patients. Most discussion about the benefits of surgery is based on studies performed in patients who are ≤ 60 years of age. Less is known about the benefits of the procedure in the elderly population. The authors undertook a review of the literature on decompressive craniectomy for malignant cerebral infarction and compared the mortality and outcome data published in patients older and younger than 60 years of age. The authors discuss their analysis, with specific reference to the limitations of the studies analyzed, the outcome measures used, and the special considerations required when discussing stroke recovery in the elderly.

Methods

Studies on decompressive craniectomy for malignant middle cerebral artery infarction reported in the English literature were analyzed. A cutoff point for age of > 60 or ≤ 60 years was set, and the study population was segregated. No studies specifically analyzed patients > 60 years old. A total of 19 studies was identified, 10 of which included patients who were > 60 years of age. A comparison between the 2 age groups was made within the 10 studies and also among all the patients in the 19 studies. Mortality rates and outcome scores were assessed for each study, and a Barthel Index (BI) score of < 60 or a modified Rankin Scale (mRS) score of > 3 was considered to represent a poor outcome. Rates were compared using the Fisher exact test, and p values < 0.05 were considered statistically significant.

Results

Nineteen studies were found, which included 273 patients undergoing decompressive craniectomy for malignant cerebral infarcts. Ten of these studies included 73 patients (26.7%) who were > 60 years of age. The mean follow-up times ranged from 5.75 to 12.3 months in the > 60-years group and 4.2 to 28 months in the ≤ 60-years group. The mortality rate was significantly higher, at 51.3% in the > 60-years group (37 of 72 patients) compared with 20.8% (41 of 197 patients) in the ≤ 60-years group (p < 0.0001). Similarly, patients who survived in the > 60-years group had significantly higher rates of poor outcomes, at 81.8% (27 of 33), compared with 33.1% (47 of 142) in the ≤ 60-year-old group (p < 0.0001). The BI was the most commonly used primary outcome measure (15 out of 19 studies), followed by the mRS score, which was used in 4 studies.

Conclusions

The mortality rate and functional outcome, as measured by the BI and mRS, were significantly worse in patients > 60 years of age following decompressive craniectomy for malignant infarction. Age is an important factor to consider in patient selection for surgery. However, cautious interpretation of the results is required because the outcome scores that were used only measure physical disability, whereas other factors, including psychosocial, financial, and caregiver burden, should be considered in addition to age alone.

Management of intracranial hypertension

Raised intracranial pressure (ICP) is a life threatening condition that is common to many neurological and non-neurological illnesses. Unless recognized and treated early it may cause secondary brain injury due to reduced cerebral perfusion pressure (CPP), and progress to brain herniation and death. Management of raised ICP includes care of airway, ventilation and oxygenation, adequate sedation and analgesia, neutral neck position, head end elevation by 20 degrees-30 degrees, and short-term hyperventilation (to achieve PCO(2) 32-35 mm Hg) and hyperosmolar therapy (mannitol or hypertonic saline) in critically raised ICP. Barbiturate coma, moderate hypothermia and surgical decompression may be helpful in refractory cases. Therapies aimed directly at keeping ICP <20 mmHg have resulted in improved survival and neurological outcome. Emerging evidence suggests that cerebral perfusion pressure targeted therapy may offer better outcome than ICP targeted therapies.

Management of intracranial hypertension

Effective management of intracranial hypertension involves meticulous avoidance of factors that precipitate or aggravate increased intracranial pressure. When intracranial pressure becomes elevated, it is important to rule out new mass lesions that should be surgically evacuated. Medical management of increased intracranial pressure should include sedation, drainage of cerebrospinal fluid, and osmotherapy with either mannitol or hypertonic saline. For intracranial hypertension refractory to initial medical management, barbiturate coma, hypothermia, or decompressive craniectomy should be considered. Steroids are not indicated and may be harmful in the treatment of intracranial hypertension resulting from traumatic brain injury.

Surgery for brain edema

Brain edema is a common pathophysiological process seen in many neurosurgical conditions. It can be localized in relation to focal lesions or generalized in diffuse types of brain injury. In addition to local adverse effects occurring at a cellular level, brain edema is associated with raised intracranial pressure (ICP), and both phenomena contribute to poor outcome in patients. One of the goals in treating patients with acute neurosurgical conditions in intensive care is to control brain edema and maintain ICP below target levels. The mainstay of treatment is medical therapy to reduce edema, but in certain patients--for example, those with diffuse severe traumatic brain injury (TBI) and malignant middle cerebral artery infarction--such treatment is not effective. In these patients, opening the skull (decompressive craniectomy) to reduce ICP is a potential option. In this review the authors discuss the role of decompressive craniectomy as a surgical option in patients with brain edema in the context of a variety of pathological entities. They also address the current evidence for the technique (predominantly observational series) and the ongoing randomized studies of decompressive craniectomy in TBI and ischemic stroke.

Management of intracranial hypertension

Effective treatment of intracranial hypertension involves meticulous avoidance of factors that precipitate or aggravate increased intracranial pressure. When intracranial pressure becomes elevated, it is important to rule out new mass lesions that should be surgically evacuated. medical management of increased intracranial pressure should include sedation and paralysis, drainage of cerebrospinal fluid, and osmotherapy with either mannitol or hypertonic saline. For intracranial hypertension refractory to initial medical management, barbiturate coma, hypothermia, or decompressive craniectomy should be considered. Steroids are not indicated and may be harmful in the treatment of intracranial hypertension resulting from traumatic brain injury.

Recovery from ischemic stroke: a translational research perspective for neurology

Ischemic stroke is the most frequent neurological disease, characterized by an age-related incidence and chronic disability in the majority of patients. A great challenge in acute stroke is to predict the degree to which a patient will eventually recover. Magnetic resonance imaging has revealed that treatment-induced reperfusion limits the extent of ischemic brain damage, thereby enabling rapid and profound recovery. Nevertheless, patients may retain deficits in motor, sensory or cognitive functions due to the residual lesion. Functional neuroimaging and transcranial magnetic stimulation have shown that recovery is associated with abnormal activation in the perilesional vicinity and in brain areas remote from the lesion. This is likely related to altered functional properties or morphological changes in both cerebral hemispheres. Recent neurorehabilitative strategies, including forced use, mental imagery and peripheral nerve or cortex stimulation, aim at modulating these functional networks. Accordingly, translational research has provided new vistas on the neurobiological mechanisms of recovery and opened future avenues for science-based pharmacological and neurophysiological training strategies in stroke.