Altered static and dynamic cerebellar-cerebral functional connectivity in acute pontine infarction.

This study investigates abnormalities in cerebellar-cerebral static and dynamic functional connectivity among patients with acute pontine infarction, examining the relationship between these connectivity changes and behavioral dysfunction. Resting-state functional magnetic resonance imaging was utilized to collect data from 45 patients within seven days post-pontine infarction and 34 normal controls. Seed-based static and dynamic functional connectivity analyses identified divergences in cerebellar-cerebral connectivity features between pontine infarction patients and normal controls. Correlations between abnormal functional connectivity features and behavioral scores were explored. Compared to normal controls, left pontine infarction patients exhibited significantly increased static functional connectivity within the executive, affective-limbic, and motor networks. Conversely, right pontine infarction patients demonstrated decreased static functional connectivity in the executive, affective-limbic, and default mode networks, alongside an increase in the executive and motor networks. Decreased temporal variability of dynamic functional connectivity was observed in the executive and default mode networks among left pontine infarction patients. Furthermore, abnormalities in static and dynamic functional connectivity within the executive network correlated with motor and working memory performance in patients. These findings suggest that alterations in cerebellar-cerebral static and dynamic functional connectivity could underpin the behavioral dysfunctions observed in acute pontine infarction patients.

Acute peripheral facial paralysis caused by tegmental pontine infarction.

Facial paralysis presents as unilateral mouth drooping and lagophthalmos. The main causes of peripheral facial paralysis are Bell's palsy and Ramsay-Hunt syndrome. However, rarely occurring pontine infarctions of the facial nucleus also manifest a lower motor neuron pattern of facial paralysis. We report a case of a man in his 50s who presented to the emergency department with unilateral peripheral facial paralysis. The initial diffusion-weighted images were unremarkable, and the patient was managed as per guidelines for hypertensive encephalopathy or Bell's palsy. On the 3rd day after admission, he was diagnosed with left pontine infarction and suspected infarction of the left anterior inferior cerebellar artery. We propose that in similar cases, re-examination of imaging results should be considered, as diffusion-weighted imaging is characteristically prone to generate false-negative results in patients with early onset or posterior circulation infarction.

Body representation after a stroke in the brainstem.

BACKGROUND: Lesion occurring in the brainstem may cause a postural tilt and balance disorders, which could be due to an inaccurate perception of the body orientation. The objective of this study was to determine the effects of a brainstem stroke on body representation in horizontal and frontal plane, and links with impaired posture and neuroanatomy. METHODS: Forty patients with stroke in left brainstem (L-BS) or right (R-BS) were compared with 15 matched control subjects (C). The subjective straight-ahead (SSA) was investigated using a method disentangling lateral deviation and tilt components of error. RESULTS: The L-BS patients had contralesional lateral deviation of SSA. In addition, they showed an ipsilesional tilt, more severe for the trunk than for the head. By contrast, in R-BS patients, the representation of the body midline was fairly accurate in both the horizontal and frontal planes and did not differ from that of control subjects. CONCLUSION: This work highlights an asymmetry of representation of body associated with left brainstem lesions extending to the right cerebral hemisphere. This deviation appears only after a left lesion, which may point to a vestibular dominance. These results open a new perspective of neuro-rehabilitation of postural disorders after a stroke, with the correction of the representation of body orientation.

A New Neurological Screening Approach for Diagnosing Brainstem Infarction Using the Calling Method and Familiar Voices.

This report proposes a new approach to assess dysarthria in patients with brainstem infarction by involving familiar individuals. Collaboration provides valuable insights compared to subjective traditional methods. A man in his 70s presented with resolved positional vertigo. Standard neurological tests showed no abnormalities, and inquiries with the patient's friend did not reveal voice changes. While inquiring about voice changes with family, friends, and acquaintances is a common practice in clinical settings, our approach involved the patient calling out to his friend from a distance. Despite the physician detecting no abnormalities, the friend noticed a lower voice. Subsequent magnetic resonance imaging (MRI) confirmed brainstem infarction. Early and subtle symptoms of brainstem infarction pose a detection challenge and can lead to serious outcomes if overlooked. This report provides the first evidence that distance calling can detect subtle voice changes associated with brainstem infarction potentially overlooked by conventional neurological examinations, including inquiries with individuals familiar with the patient's voice. Detecting brainstem infarction in emergency department cases is often missed, but conducting MRIs on every patient is not feasible. This simple method may identify patients overlooked by conventional screening who should undergo neuroimaging such as MRI. Further research is needed, and involving non-professionals in assessments could significantly advance the diagnostic process.

"Uncrossed Central Facial Paralysis" Caused by Pontine Infarction: A Case Report.

INTRODUCTION: We report a patient with extraordinary pontine infarction-induced contralateral central facial palsy and weakened limb strength. CASE REPORT: This is a 66-year-old man with left arm movement difficulty for 10 days and worsening over the last 1 day. His left nasolabial fold flattening and left arm strength and sensory were decreased. He could not complete the finger-nose test well with his right hand. Magnetic resonance and magnetic resonance angiography tests confirmed his right pontine acute infarction but without large vessel stenosis or occlusion. CONCLUSION: "Uncrossed paralysis" patients may present with contralateral face and body weakness with pontine infarcts, if the infarct occurs above the level of the facial nucleus head, and may be simmilar with the higher level pontine lesions or cerebrum semisphere infarction, which need particular attention during clinical practice.

Neuroimaging markers of early neurological deterioration in acute isolated pontine infarction.

BACKGROUND: Imaging indicators of early neurological deterioration (END) in patients with acute isolated pontine infarctions (AIPI) remained ambiguous. We aimed to find more specific neuroimaging markers for the development of END in patients with AIPI. METHODS: Patients with AIPI within 72 h of stroke onset were screened from a stroke database from January 2018 to July 2021 in the First Affiliated Hospital of Zhengzhou University. Clinical characteristics, laboratory tests, and imaging parameters were collected. The layers having the largest infarct area on diffusion-weighted imaging (DWI) and T2 sequences were chosen. On the transverse plane of DWI and sagittal plane of T2-Flair images, the maximum length (a, m) and maximum width (b, n) vertical to the length of the infarcted lesions were measured respectively. On the sagittal plane of T2-Flair image, the maximum ventrodorsal length (f) and rostrocaudal thickness (h) were measured. On the sagittal plane, lesions were evenly split into upper, middle, and lower types based on the lesion's location in the pons. The ventral and dorsal types of location were separated based on whether the ventral borders of the pons were involved on transvers plane. END was defined as a ≥2 point increase in the National Institutes of Health Stroke Scale (NIHSS) total score or a ≥1 point increase in the motor items within 72 h after admission. Multivariate logistic regression analyses were used to explore risk factors associated with END. The receiver operating characteristic (ROC) curve analysis and the area under the curve (AUC) was performed to estimate the discriminative power and determine the optimal cut-off points of imaging parameters on the prediction of END. RESULTS: A total of 218 patients with AIPI were included in the final analysis. END occurred in 61 cases (28.0%). Multivariate logistic regression analysis showed that the ventral type of lesion location was associated with END in all models adjusted. In addition, in Model 1, b (odds ratio (OR) 1.145, 95% confidence interval (95% CI), 1.007-1.301) and n (OR 1.163, 95% CI 1.012-1.336); in Model 2, b*n (OR 1.010, 95% CI 1.002-1.018); in Model 3, n (OR 1.179, 95% CI, 1.028-1.353); and in Model 4, b (OR 1.143, 95% CI 1.006-1.298) and n (OR 1.167, 95% CI 1.016-1.341) were found to be associated with END respectively after different adjustments. ROC curve analysis with END showed that the AUC, the optimal cut-off value, and its sensitivity and specificity were 0.743 (0.671-0.815), 9.850 mm, and 68.9% and 79.0% for b; 0.724 (0.648-0.801), 10.800 mm, and 57.4% and 80.9% for n; and 0.772 (0.701-0.842), 108.274 mm2, and 62.3% and 85.4% for b*n, respectively (b*n vs b: P =0.213; b*n vs n: P =0.037; b vs n: P =0.645). CONCLUSIONS: Our study revealed that besides the ventral type of lesion location, the maximum width of lesion on the transverse plane of DWI and sagittal plane of T2 image (b, n) may be imaging markers for the development of END in AIPI patients, and the product of the two (b*n) showed a better prediction value on the risks of END.

Morphological predictors of neurological deterioration in patients with acute isolated pontine infarct.

OBJECTIVE: To investigate morphological predictors of neurological deterioration (ND) in patients with acute isolated pontine infarct. METHODS: Acute isolated pontine infarct patients within 7 days after onset of stroke symptoms were included retrospectively and classified into ND and non-ND groups. Morphological phenotypes (paramedian pontine infarct [PPI], atypical PPI, small deep infarct, and other types), topographical location, and lesion size were evaluated on axial diffusion-weighted imaging. RESULTS: There were 210 eligible patients, of whom 62 patients had ND (29.5%). The proportion of PPI was significantly higher in ND than that in non-ND (62.9% vs 39.6%). ND occurred more frequently in PPI patients than non-PPI patients (39.8% vs 20.5%). PPI located more frequently in lower pontine (20.4% vs 8.0%) and less in upper pontine (17.3% vs 30.4%, P = 0.028), and had larger ventro-dorsal length (13.8 ± 3.8 vs 9.9 ± 3.1) and width (8.3 ± 2.3 vs 6.2 ± 1.8) than non-PPI patients. The morphological phenotype of PPI was an independent risk factor for ND (OR 4.81, 95%CI 1.54-15.07, P = 0.007) in patients with isolated pontine infarct. The ventro-dorsal length of pontine infarct lesion was associated with ND (OR 1.18, 95%CI 1.01, 1.37, P = 0.034) in PPI patients. CONCLUSIONS: The morphological phenotype of PPI was a potential predictor for ND in patients with acute isolated pontine infarct. The ventro-dorsal length of pontine infarct lesion was possibly associated with ND in PPI patients.

A Case of Sudden Cardiac Arrest After Brainstem Infarction.

Research on the causes of sudden cardiac arrest (CA) after ischemic stroke, especially disruption of the autonomic nervous system's central control, has recently focused more on the widespread cortical and subcortical network than on autonomic circuits at the spinal and brainstem level. However, no clinical case of sudden CA requiring cardiopulmonary resuscitation (CPR) after brainstem infarction has been reported. We report a case of a 78-year-old woman who died suddenly from a brainstem infarction. Her husband heard a falling sound and found her unresponsive and lying with agonal breathing. The initial cardiac rhythm was pulseless electrical activity confirmed by emergency medical technicians. Recovery of spontaneous circulation was achieved after CPR. Basilar artery occlusion was shown on computed tomography, but no other findings that could have caused CA were found. Targeted temperature management was initiated, but she died on hospital day 22. Brainstem infarction may cause sudden CA; therefore, definitive treatment may achieve better outcomes.

Basilar artery curvature increases the risk of posterior circulation infarction occurrence in patients without vertebrobasilar stenosis.

INTRODUCTION: Limited cross-sectional or case-control studies have identified the relationship between basilar artery (BA) curvature and posterior circulation infarction (PCI). This study aimed to identify the influence of BA curvature severity on the risk of PCI occurrence in patients without vertebrobasilar stenosis through a prospective cohort study. METHODS: In this study, we enrolled 171 patients with BA dolichosis but without vertebrobasilar stenosis. The BA geometric parameters were evaluated on MRA. The primary outcome was the occurrence of PCI, mainly referring to cerebellar and/or brainstem infarction. Cox proportional hazard models were used to detect possible predictors of PCI. RESULTS: Among them, 134 (78.4%) patients were diagnosed with BA curvature, including 124 with moderate curvature and 10 with prominent curvature. The defined PCI occurrence was observed in 32 (18.7%) patients with a median follow-up time of 45.6 months. Cox proportional hazard analysis showed that BA prominent curvature (HR = 6.09; 95% CI: 1.36-27.28; P = 0.018) significantly increased the risk of PCI occurrence, and bending length (BL) was also significantly associated with PCI occurrence, with the adjusted HR per 1-mm increase of BL of 1.09 (95% CI: 1.01-1.18; P = 0.040). In the subgroup analysis stratified by age, BA prominent curvature was highly associated with PCI occurrence in patients aged > 61 years (HR = 11.76; 95% CI: 1.21-113.90; P = 0.033). Additionally, good antiplatelet therapy adherence could significantly reduce the risk of PCI occurrence. CONCLUSION: BA curvature may increase the risk of PCI occurrence, especially in elderly patients with prominent curvature. Improving adherence to antiplatelet therapy can help reduce the risk of PCI occurrence.

Effect of Mid-Basilar Artery Angle and Plaque Characteristics on Pontine Infarction in Patients with Basilar Artery Plaque.

AIMS: The basilar artery (BA) geometry and plaque characteristics may play an important role in the development of atherosclerosis. This study was performed to explore the relationship between the mid-BA angle and plaque characteristics and its effect on pontine infarction using high-resolution magnetic resonance imaging and three-dimensional time-of-flight magnetic resonance angiography. METHODS: In total, 77 patients with BA plaques were included in this study. According to the presence of acute pontine infarction on diffusion-weighted imaging, the patients were divided into a pontine infarction group and pontine non-infarction group. The mid-BA angle, plaque burden, stenosis ratio, positive remodeling, and intraplaque hemorrhage were evaluated to investigate their effects on stroke. RESULTS: The pontine infarction group had a greater plaque burden, stenosis ratio, positive remodeling, and mid-BA angle than the pontine non-infarction group. The correlation between the plaque burden and mid-BA angle was the highest (r=0.441, P＜0.001). Multivariate logistic regression analysis showed that the plaque burden (odds ratio, 1.164; 95% confidence interval, 1.093-1.241; P＜0.001) was an independent risk factor for pontine infarction. CONCLUSION: The mid-BA angle may increase the incidence of pontine infarction by increasing the plaque burden.

A radiomics feature-based machine learning models to detect brainstem infarction (RMEBI) may enable early diagnosis in non-contrast enhanced CT.

OBJECTIVES: Magnetic resonance imaging has high sensitivity in detecting early brainstem infarction (EBI). However, MRI is not practical for all patients who present with possible stroke and would lead to delayed treatment. The detection rate of EBI on non-contrast computed tomography (NCCT) is currently very low. Thus, we aimed to develop and validate the radiomics feature-based machine learning models to detect EBI (RMEBIs) on NCCT. METHODS: In this retrospective observational study, 355 participants from a multicentre multimodal database established by Huashan Hospital were randomly divided into two data sets: a training cohort (70%) and an internal validation cohort (30%). Fifty-seven participants from the Second Affiliated Hospital of Xuzhou Medical University were included as the external validation cohort. Brainstems were segmented by a radiologist committee on NCCT and 1781 radiomics features were automatically computed. After selecting the relevant features, 7 machine learning models were assessed in the training cohort to predict early brainstem infarction. Accuracy, sensitivity, specificity, positive predictive value, negative predictive value, F1-score, and the area under the receiver operating characteristic curve (AUC) were used to evaluate the performance of the prediction models. RESULTS: The multilayer perceptron (MLP) RMEBI showed the best performance (AUC: 0.99 [95% CI: 0.96-1.00]) in the internal validation cohort. The AUC value in external validation cohort was 0.91 (95% CI: 0.82-0.98). CONCLUSIONS: RMEBIs have the potential in routine clinical practice to enable accurate computer-assisted diagnoses of early brainstem infarction in patients with NCCT, which may have important clinical value in reducing therapeutic decision-making time. KEY POINTS: • RMEBIs have the potential to enable accurate diagnoses of early brainstem infarction in patients with NCCT. • RMEBIs are suitable for various multidetector CT scanners. • The patient treatment decision-making time is shortened.

An isolated pontine infarct extending to the basal pontine surface has a higher abnormal ankle-brachial index.

Patients with ischemic stroke and branch atheromatous disease (BAD) have worse neurological deficits and prognoses than those with small vessel occlusion (SVO). However, both disorders are forms of deep brain infarctions. This study aimed to investigate an MRI-based etiological classification for isolated pontine infarctions and assess differences in vascular risk factors and peripheral arterial disease among etiological subtypes. Consecutive data of patients admitted for acute ischemic stroke or transient ischemic attack between August 2016 and July 2019 were reviewed. Acute isolated pontine infarcts were classified into 3 groups: BAD, SVO, and large-artery atherosclerosis (LAA), according to basilar or vertebral artery steno-occlusion and the extent of the infarct lesion on the basal pontine surface as displayed on magnetic resonance imaging and angiography. Vascular risk factors, ankle-brachial index (ABI), and brachial-ankle pulse wave velocity were analyzed in the 3 groups. Among 64 enrolled patients, BAD was the most common cause of isolated pontine infarct. The BAD group had a higher frequency of abnormal ABI and hypertension than the SVO group. The BAD group had abnormal ABI and hyperlipidemia more frequently than the LAA group. No significant difference was found in diabetes or brachial-ankle pulse wave velocity incidence between the BAD and SVO groups. ABI and vascular risk factors in the BAD group were more similar to those in the LAA group than to those in the SVD group. This finding suggests that pontine lesions extending to the basal pontine surface have an atherosclerotic mechanism in BAD, requiring potent antiplatelet therapy for the secondary prevention of ischemic stroke.

Highest resolution microCT scan of the human brainstem reveals putative anatomical basis for infrequency of medial medullary syndrome.

Ischemic strokes affecting the medial medulla are exceedingly rare. The anatomical basis for the relative infrequency of this stroke syndrome has been largely uninvestigated due to historically coarse MRI and CT scan resolution. We capture and digitally dissect the highest-ever-resolution diffusible iodine-based contrast-enhanced CT (diceCT) scanned images of a cadaveric brainstem to map arterial territories implicated in medial medullary infarctions. 3D reconstructions show that within the anterior spinal artery territory previously implicated in medial medullary syndrome (MMS), there are numerous, small sulcal artery branches perforating the medulla within the anterior median fissure. These branches proceed in parallel through the anteroposterior depth of the medulla as expected; however, we also identify a network of intraparenchymal, rostrocaudal anastomoses between these sulcal perforating branches. This network of intraparenchymal sulcal artery anastomoses has never been described and may provide a significant collateral supply of oxygenated blood flow throughout the medial medulla. By ramifying deeper tissues, these anastomoses can help explain the infrequency of MMS.