The Piano Man: A Case Report of Anterior Thalamic Infarct with Dementia and Preserved Music Ability.

OBJECTIVE: The thalamus is the integrative hub of the brain with reciprocal connections throughout the cortex. This case report describes a right-handed 81-year-old male patient who experienced sudden onset cognitive impairment following a focal left anterior thalamic infarct. METHODS: With consent/assent, the patient was seen for a short neuropsychological assessment 6 weeks post stroke. Neuropsychological assessment included review of medical history, collateral intake, the Toronto Cognitive Assessment, Frontal Systems Behavior Scale-Family Rating Form, the Neuropsychiatric Inventory Questionnaire, and piano performance. RESULTS: The assessment revealed impaired performance on measures of orientation, memory, executive function, and language, as well as symptoms including hallucinations, apathy, and hypersomnolence, consistent with thalamic dementia. Remarkably, in this context, the patient maintained an ability to play piano and read music. CONCLUSIONS: The case has implications for understanding the complex integrative functions of the thalamus, including how profound impairment can simultaneously present with cognitive strengths that may not be captured by performance on neuropsychological testing. This case also suggests that magnetic resonance imaging may be indicated in cases presenting with vascular risk factors and sudden onset cognitive impairment, given that computed tomography may not be sensitive to small subcortical infarcts.

Photochemically induced thalamus infarction impairs cognition in a mouse model.

BACKGROUND: Small subcortical infarcts account for up to 25% of ischaemic strokes. Thalamus is one of the subcortical structures that commonly manifest with lacunar infarcts on MRI of the brain. Studies have shown that thalamus infarction is associated with cognitive decline. However, due to the lack of proper animal models, little is known about the mechanism. We aimed to establish a focal thalamus infarction model, characterise the infarct lesion and assess functional effects. METHODS: Male C57BL/6J mice were anaesthetised, and Rose Bengal dye was injected through the tail vein. The right thalamus was illuminated with green laser light by stereotactic implantation of optic fibre. Characteristics of the infarct and lesion evolution were evaluated by histological analysis and 7T MRI at various times. The cognitive and neurological functions were assessed by behavioural tests. Retrograde tracing was performed to analyse neural connections. RESULTS: An ischaemic lesion with small vessel occlusion was observed in the thalamus. It became a small circumscribed infarct with reactive astrocytes accumulated in the infarct periphery on day 21. The mice with thalamic infarction demonstrated impaired learning and memory without significant neurological deficits. Retrogradely labelled neurons in the retrosplenial granular cortex were reduced. CONCLUSION: This study established a mouse model of thalamic lacunar infarction that exhibits cognitive impairment. Neural connection dysfunctions may play a potential role in post-stroke cognitive impairment. This model helps to clarify the pathophysiology of post-stroke cognitive impairment and to develop potential therapies.

A clinical study of artery of Percheron infarction.

Artery of Percheron (AOP) infarction, a rare cause of acute altered mental status (AMS), is characterized by bilateral paramedian thalamic infarction. The aim of this study was to review the clinical manifestation, radiological patterns, treatment, and prognosis of patients with AOP infarction. This retrospective case series included patients with AOP infarction from 2009 to 2020 from a medical center in Taiwan. We defined AOP infarction as acute bilateral paramedian thalamic infarction from magnetic resonance imaging, and patients were further categorized by their additional AOP territorial involvements. We determined outcomes with the modified Rankin Scale at discharge. Among the 10 included patients, AMS was the most common presentation (90%). We identified two patients with bilateral vertebral artery (VA), five with unilateral posterior cerebral artery (PCA), and one with bilateral PCA occlusion. Atherosclerosis was the most common presumed etiology (60%). Two and eight patients had favorable and unfavorable prognoses, respectively. PCA occlusion, rather than VA and BA occlusion, was common in angiography. Residual symptoms often resulted in significant disability at discharge. Basilar tip syndrome may share indistinguishable thalamic infarct patterns with AOP infarction but could be differentiated by angiography and other infarcted territories.

Brain plasticity after rehabilitation in a severe case of artery of Percheron stroke assessed with multimodal MR imaging.

Artery of Percheron (AOP) stroke is a rare event. We describe an AOP stroke involving both thalami and the midbrain, resulting in a multifunctional clinical impairment. Intensive inpatient multidisciplinary rehabilitation favored the recovery of motor deficits, together with the improvement of cognitive dysfunctions. MRI assessment in the chronic post-stroke phase showed structural and functional reorganization in response to the extended thalamic tissue damage and absence of revascularization. Thalamo-cortical networks involving frontal and prefrontal regions, as well as parietal areas were disrupted, whereas increased functional thalamo-occipital connectivity was found. This report sheds light on brain reorganization following AOP stroke after rehabilitation..

Isolated unilateral thalamic venous infarct in a toddler.

Isolated deep cerebral venous thrombosis (CVT), especially involving only the right thalamus, is one of the rarest forms of intracranial venous thrombosis in a child. The anatomy and flow patterns of the deep cerebral venous system are complex and usually, the thrombosis of the internal cerebral veins (ICV) results in thalamic infarction bilaterally. The focal infections, thalamic tumours and vascular malformations may have overlapping clinicoradiological patterns. The treating team should be able to recognise the atypical phenotypes of the deep CVT at the earliest, which can facilitate apt treatment and obviate the need for unnecessary investigations and interventions. We present a rare case of an isolated right thalamic acute venous infarct secondary to bilateral ICV thrombosis in a toddler who was successfully managed by timely diagnosis and with only conservative therapy.

Artery of Percheron Occlusion in China: A Case Report and Chinese Literature Review.

INTRODUCTION: The artery of Percheron (AOP) is a rare anatomical variant in which bilateral paramedian thalami are supplied by a single vascular branch arising from the P1 segment of the posterior cerebral artery. We present a case of AOP occlusion presenting as loss of consciousness and summarize the literature in Chinese to find the clinical characteristics. CASE REPORT: An 83-year-old woman was found unconscious for 1 day at home and was sent to the hospital the next day. Cerebral magnetic resonance imaging on day 1 of the patient showed a recent bilateral paramedian thalamic infarction. Simultaneously, magnetic resonance angiography found evident artery stenosis of the right P1 segment of the posterior cerebral artery, suggesting that the patient was diagnosed with AOP occlusion. Since the patient has missed the best time for thrombolytic therapy, anticoagulant therapy was given immediately; as the patient was then found to have pulmonary infections, antibiotic therapy was also initiated. The neurological status of this patient improved very slow. In about 2 weeks, the patient becomes more conscious but still could not speak or move. CONCLUSION: Our report suggests that unusual mood disorder and language disorder of aged patients might indicate the AOP occlusion, and cerebral imaging of magnetic resonance imaging (better with magnetic resonance angiography) should be performed to establish the diagnosis of AOP occlusion. The fast and accurate diagnosis of stroke because of AOP occlusion could best benefit the patients.

Crossed Choreoathetosis Caused by Unilateral Thalamic Hemorrhage.

In general, involuntary movements after stroke are due to a disturbance in the unilateral cortico-basal ganglia loop and appear contralateral to stroke lesions. Crossed involuntary movements after unilateral stroke are very rare. We observed a case of crossed involuntary movements in the left upper limb and right lower limb after a right thalamic hemorrhage expanded to the right subthalamic nucleus. We considered a possible three-step theory as the basis of crossed choreoathetosis. This case informs our better understanding of the cortico-basal ganglia loop and involuntary movements after stroke.

Isolated acute pseudobulbar palsy with infarction of artery of percheron: case report and literature review.

INTRODUCTION: Pseudobulbar palsy (PBP) is characterized by supranuclear lesions in the corticobulbar pathway. Neoplasia, inflammatory, demyelinating, and stroke are possible etiologies of this disorder. CASE REPORT: We report an elderly female who presented with dysarthria. She was dysarthric with a hypernasal voice, no apraxia or aphasia was observed. Tongue movements were slow with limited amplitude. Her soft palate dropped bilaterally; gag reflex was present. Also, she reported swallowing difficulty and choking with her saliva. Bilateral vertical and horizontal gaze were intact to either voluntary or oculocephalic movements. A cranial CT scan was suggestive of artery of Percheron (AOP) infarction. Brain magnetic resonance imaging showed hypersignal on diffusion-weighted and T2-weighted images and hyposignal on apparent diffusion coefficient in both thalami. CT angiography scan revealed an AOP originating from the left posterior cerebral artery. The swallowing study with a videofluoroscopic demonstrated oral and pharyngeal phases with severe dysfunction. CONCLUSION: To the authors' knowledge, there are two cases of individuals with artery of Percheron infarction who developed PBP associated with other clinical syndromes. Still, isolated PBP following infarction of Percheron's artery was not reported. We hypothesized that the PBP may have occurred because of the existence of vascular territory variations in the perforating arteries that arise from the AOP.

Outcome after acute ischemic stroke is linked to sex-specific lesion patterns.

Acute ischemic stroke affects men and women differently. In particular, women are often reported to experience higher acute stroke severity than men. We derived a low-dimensional representation of anatomical stroke lesions and designed a Bayesian hierarchical modeling framework tailored to estimate possible sex differences in lesion patterns linked to acute stroke severity (National Institute of Health Stroke Scale). This framework was developed in 555 patients (38% female). Findings were validated in an independent cohort (n = 503, 41% female). Here, we show brain lesions in regions subserving motor and language functions help explain stroke severity in both men and women, however more widespread lesion patterns are relevant in female patients. Higher stroke severity in women, but not men, is associated with left hemisphere lesions in the vicinity of the posterior circulation. Our results suggest there are sex-specific functional cerebral asymmetries that may be important for future investigations of sex-stratified approaches to management of acute ischemic stroke.

Characterizing Diaschisis-Related Thalamic Perfusion and Diffusion After Middle Cerebral Artery Infarction.

Background and Purpose: Ipsilateral thalamic diaschisis (ITD) initially describes functional depression of the thalamus ipsilateral to a supratentorial lesion, but accumulating evidence has shown morphological changes also occur. Therefore, we aimed to characterize thalamic perfusion and diffusion related to ITD over time and their inter-relationships after middle cerebral artery infarction. Methods: Eighty-five patients with middle cerebral artery infarction who underwent diffusion kurtosis imaging and arterial spin labeling were retrospectively included. ITD was diagnosed as ipsilateral thalamic hypoperfusion present on ≥2 cerebral blood flow maps. The thalamic asymmetrical index was calculated as (ipsilateral value−contralateral value)/contralateral value×100%. Finally, the inter-relationships of thalamic perfusion and diffusion were analyzed. Results: ITD was present in 56/85 patients (65.9%, ITD+). In ITD+ patients, larger abnormal perfusion volume, higher perfusion-infarct mismatch and lower rates of focal hyperperfusion were observed than ITD− patients. Infarction affecting the corona radiata were more frequent among ITD+ patients. Mean kurtosis were slightly but significantly increased within the ipsilateral thalamus compared with the contralateral one in ITD+ patients of subacute and chronic groups, while fractional anisotropy was significantly increased in subacute group but decreased in chronic group for both ITD+ and ITD− patients. Mean diffusivity was significantly increased in ITD+ patients of chronic group. Furthermore, the AICBF was negatively and significantly correlated with AIMK and AIFA in ITD+ patients in subacute group, and AIMD, even after adjustment for abnormal perfusion volume and days from symptoms onset, in chronic group. ITD+ patients had significantly higher National Institutes of Health Stroke Scale and modified Rankin Scale scores at admission and discharge and also showed a trend to independent association with clinical outcome at discharge. Conclusions: The combination of arterial spin labeling and diffusion kurtosis imaging can reveal early, time-specific thalamic perfusion and diffusion changes after middle cerebral artery infarction. ITD-related hypoperfusion was significantly correlated with underlying microstructural alterations.

Effects of acetate on cerebral blood flow, systemic inflammation, and behavior in alcohol use disorder.

BACKGROUND: Alcohol use disorders (AUDs) are associated with altered regulation of physiological processes in the brain. Acetate, a metabolite of ethanol, has been implicated in several processes that are disrupted in AUDs including transcriptional regulation, metabolism, inflammation, and neurotransmission. To further understand the effects of acetate on brain function in AUDs, we investigated the effects of acetate on cerebral blood flow (CBF), systemic inflammatory cytokines, and behavior in AUD. METHODS: Sixteen participants with AUD were recruited from a nonmedical, clinically managed detoxification center. Each participant received acetate and placebo in a randomly assigned order of infusion and underwent 3T MR scanning using quantitative pseudo-continuous arterial spin labeling. Participants and the study team were blinded to the infusion. CBF values (ml/100 g/min) extracted from thalamus were compared between placebo and acetate using a mixed effect linear regression model accounting for infusion order. Voxel-wise CBF comparisons were set at threshold of p < 0.05 cluster-corrected for multiple comparisons, voxel-level p < 0.0001. Plasma cytokine levels and behavior were also assessed between infusions. RESULTS: Fifteen men and 1 woman were enrolled with Alcohol Use Disorders Identification Test (AUDIT) scores between 13 and 38 with a mean of 28.3 ± 9.1. Compared to placebo, acetate administration increased CBF in the thalamus bilaterally (Left: 51.2 vs. 68.8, p < 0.001; Right: 53.7 vs. 69.6, p = 0.001), as well as the cerebellum, brainstem, and cortex. Older age and higher AUDIT scores were associated with increases in acetate-induced thalamic blood flow. Cytokine levels and behavioral measures did not differ between placebo and acetate infusions. CONCLUSIONS: This pilot study in AUD suggests that during the first week of abstinence from alcohol, the brain's response to acetate differs by brain region and this response may be associated with the severity of alcohol dependence.

Stroke masquerading as cardiac arrest: the artery of Percheron.

The artery of Percheron (AOP) is a rare arterial variant of the thalamic blood supply. Due to the densely packed collection of nuclei it supplies, an infarction of the AOP can be devastating. Here we highlight a patient who had an AOP stroke in the community, which was initially managed as cardiac arrest. AOP strokes most often present with vague symptoms such as reduced conscious level, cognitive changes and confusion without obvious focal neurology, and therefore are often missed at the initial clinical assessment. This case highlights the importance of recognising an AOP stroke as a cause of otherwise unexplained altered consciousness level and the use of MRI early in the diagnostic work-up.

Artery of Percheron infarct: hiding in plain sight.

A 54-year-old woman presented to the emergency department with fluctuating consciousness without localising signs and non-specific neurology. Urgent computed tomography (CT) was unremarkable and differentials of opioid overdose or post-ictal state were considered. Magnetic resonance imaging of the brain demonstrated an artery of Percheron (AOP) infarct; resulting from occlusion of an uncommon anatomical variant in the thalamic and midbrain circulation. This should be considered in patients presenting with fluctuating consciousness and normal CT.

[Bilateral paramedian thalamic infraction due artery of Percheron occlusion]. / Infarto talámico paramedial bilateral por oclusión de la arteria de Percherón.

INTRODUCTION: Artery of Percheron (AOP) is an anatomical variant responsible for the bilateral irrigation of both the medial thalami and rostral sector of the brainstem. Its obstruction causes infarcts in these areas. OBJECTIVE: To describe a clinical case of AOP infarction, highlighting the clinical and imaging fin dings to consider this pathology in the pediatric population with acute altered state of consciousness. CLINICAL CASE: A healthy 17-year-old adolescent presented with altered state of consciousness and diplopia, which was resolved in a few hours. Brain MRI showed a bilateral medial thalamic infarction, diagnosing an occlusion of the AOP. The only presumed etiological element was the presence of a patent foramen ovale. Surgical correction of the cardiac defect and anticoagulation were performed, with complete recovery. CONCLUSION: It is essential to know the clinical-radiological pattern of this condition, which is very characteristic, but infrequent in the pediatric age.

A plant-based meal affects thalamus perfusion differently than an energy- and macronutrient-matched conventional meal in men with type 2 diabetes, overweight/obese, and healthy men: A three-group randomized crossover study.

BACKGROUND & AIMS: Reward circuitry in the brain plays a key role in weight regulation. We tested the effects of a plant-based meal on these brain regions. METHODS: A randomized crossover design was used to test the effects of two energy- and macronutrient-matched meals: a vegan (V-meal) and a conventional meat (M-meal) on brain activity, gastrointestinal hormones, and satiety in participants with type 2 diabetes (T2D; n = 20), overweight/obese participants (O; n = 20), and healthy controls (H; n = 20). Brain perfusion was measured, using arterial spin labeling functional brain imaging; satiety was assessed using a visual analogue scale; and plasma concentrations of gut hormones were determined at 0 and 180 min. Repeated-measures ANOVA was used for statistical analysis. Bonferroni correction for multiple comparisons was applied. The Hedge's g statistic was used to measure the effect size for means of paired difference between the times (180-0 min) and meal types (M-V meal) for each group. RESULTS: Thalamus perfusion was the highest in patients with T2D and the lowest in overweight/obese individuals (p = 0.001). Thalamus perfusion decreased significantly after ingestion of the M-meal in men with T2D (p = 0.04) and overweight/obese men (p = 0.004), and it decreased significantly after ingestion of the V-meal in healthy controls (p < 0.001; Group x Meal x Time: F = 3.4; p = 0.035). The effect size was -0.41 (95% CI, -1.14 to 0.31; p = 0.26) for men with diabetes; -0.72 (95% CI, -1.48 to 0.01; p = 0.05) for overweight/obese men; and 0.82 (95% CI, 0.09 to 1.59; p = 0.03) for healthy men. Postprandial secretion of active GLP-1 increased after the V-meal compared with the M-meal by 42% (95% CI 25-62%; p = 0.003) in men with T2D and by 41% (95% CI 24-61%; p = 0.002) in healthy controls. Changes in thalamus perfusion after ingestion of both test meals correlated with changes in satiety (r = +0.68; p < 0.01), fasting plasma insulin (r = +0.40; p < 0.01), C-peptide (r = +0.48; p < 0.01) and amylin (r = +0.55; p < 0.01), and insulin secretion at 5 mmol/l (r = +0.77; p < 0.05). CONCLUSIONS: The higher postprandial GLP-1 secretion after the V-meal in men with T2D, with concomitant greater satiety and changes in thalamus perfusion, suggest a potential use of plant-based meals in addressing the key pathophysiologic mechanisms of food intake regulation. Trial registration ClinicalTrials.gov number, NCT02474147.