Stroke of bad luck?

Emotional processing impairments in patients with insula lesions following stroke

Functional imaging has helped to understand the role of the human insula as a major processing network for integrating input with the current state of the body. However, these studies remain at a correlative level. Studies that have examined insula damage show lesion-specific performance deficits. Case reports have provided anecdotal evidence for deficits following insula damage, but group lesion studies offer a number of advances in providing evidence for functional representation of the insula. We conducted a systematic literature search to review group studies of patients with insula damage after stroke and identified 23 studies that tested emotional processing performance in these patients. Eight of these studies assessed emotional processing of visual (most commonly IAPS), auditory (e.g., prosody), somatosensory (emotional touch) and autonomic function (heart rate variability). Fifteen other studies looked at social processing, including emotional face recognition, gaming tasks and tests of empathy. Overall, there was a bias towards testing only patients with right-hemispheric lesions, making it difficult to consider hemisphere specificity. Although many studies included an overlay of lesion maps to characterise their patients, most did not differentiate lesion statistics between insula subunits and/or applied voxel-based associations between lesion location and impairment. This is probably due to small group sizes, which limit statistical comparisons. We conclude that multicentre analyses of lesion studies with comparable patients and performance tests are needed to definitively test the specific function of parts of the insula in emotional processing and social interaction.

Developments in treating the nonmotor symptoms of stroke

INTRODUCTION

Stroke is among the most common causes of disability worldwide. Nonmotor symptoms of stroke are common and disabling. Many are treatable, and intervention improves the quality of life for stroke survivors.

AREAS COVERED

Here the author summarizes the evidence-based treatment of depression and other mood disorders, aphasia, hemispatial neglect, impairments of emotional communication and empathy, deficits in memory and other cognitive functions, sleep disorders, pain, fatigue, and seizures resulting from stroke. The author focuses on treatments supported by randomized controlled trials (RCTs), from the literature cited in Google Scholar, Embase, and Pubmed.

EXPERT OPINION

While behavioral rehabilitation is the most common intervention for many of the sequelae of stroke, relatively small RCTs support the use of noninvasive brain stimulation (transcranial direct current stimulation and transcranial direct current stimulation) and medications that facilitate neural plasticity and recovery. These noninvasive brain stimulation methods remain investigational for post-stroke symptoms. The strongest evidence for pharmacological intervention is in the domains of post-stroke mood disorders and epilepsy, but additional RCTs are needed to confirm the efficacy of selective serotonin reuptake inhibitors and other medications for improving recovery of cognition, language, and energy after stroke.