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.

[Capillary telangiectasia]. / Kapilläre Teleangiektasie.

Brain capillary telangiectasia is usually a small collection of dilated capillary-like vessels. In most cases it is a harmless incidental finding with no clinical significance. They are most commonly located in the pons. In terms of image morphology, they show brush-like signal extinction in T2*/SWI (susceptibility-weighted imaging) sequences and contrast enhancement in T1-weighted images. Other sequences are usually unremarkable unless they involve unusually large capillary telangiectasias. Angiographically they usually remain silent. Sometimes they are associated with venous abnormalities and/or cavernomas. Their distinctive radiographic features usually allow for a reliable diagnosis. Differential diagnostic considerations, such as differentiation from a tumorous or inflammatory process, are sometimes necessary.

Basilar Artery Tortuosity May Be Associated with Early Neurological Deterioration in Patients with Pontine Infarction.

BACKGROUND: Early neurological deterioration (END) occurs in patients with pontine infarction that is adversely associated with a long-term functional outcome. As basilar artery (BA) tortuosity may alter hemodynamics, we investigated whether factors including BA tortuosity are associated with END and poor outcome at 3 months. METHODS: We reviewed patients with acute (<7 days from stroke onset) unilateral pontine infarction mainly involving the pontine base and/or tegmental regions from January 2017 through April 2021. END was defined as increase of ≥2 in total National Institutes of Health Stroke Scale (NIHSS) score or ≥1 in motor NIHSS score within first 72 h. A poor clinical outcome was defined as modified Rankin Scale (mRS) 3-6 at 3 months. The BA tortuosity index (TI) was measured: ([actual/straight length -1] x 100). To assess interobserver agreement, TI measurements were obtained by 2 independent raters. RESULTS: The study included 245 patients; END occurred in 72 (29.3%) and 35 (14.2%) showed poor outcome at 3 months. Old age (odds ratio [OR] = 1.03, 95% confidence interval [CI] 1.004-1.062; p = 0.027), previous stroke history (OR = 2.36, 95% CI: 1.176-4.717; p = 0.016), lower initial NIHSS (OR = 0.72, 95% CI: 0.628-0.827; p < 0.001), and high BA TI (OR = 1.17, 95% CI: 1.062-1.295; p = 0.002) were associated with END. On the other hand, old age (OR = 1.04, 95% CI: 1.002-1.073; p = 0.037) and END (OR = 3.03, 95% CI: 1.429-6.403; p = 0.004) were associated with poor outcome at 3 months. CONCLUSIONS: High BA tortuosity may be a factor associated with END in patients with pontine infarction. As END was related to unfavorable clinical outcome, this risk may have to be carefully considered in patients with high BA tortuosity.

Free-floating and spinning thrombus of the basilar artery: A case report.

RATIONALE: Free-floating thrombi in the intracranial artery are rare. We report a case of a free-floating and spinning thrombus caused by turbulent flow distal to the basilar artery stenosis. We compare thrombus changes in a series of images according to time and describe the approach to treatment and thrombosis resolution.. PATIENT CONCERNS: A 55-year-old man presented to the emergency department on March 21, 2020, with left-sided weakness, bilateral limb ataxia, and a one-day history of dysarthria. Brain magnetic resonance imaging showed multifocal infarctions in the pons and cerebellum with severe basilar stenosis. DIAGNOSES: Digital subtraction angiography showed severe focal stenosis. A relatively large oval-shaped mobile thrombus was observed spinning due to turbulent flow at the distal portion of the stenosis. INTERVENTIONS: We administered a combination antithrombotic regimen of warfarin and clopidogrel for 50 days. OUTCOMES: No thrombus was observed on the third follow-up digital subtraction angiography. LESSONS: No previous study has directly observed a mobile thrombus in the intracranial artery using digital subtraction angiography. We used a combination antithrombotic strategy, which was effective after long-term, rather than short-term, use.

[Multiple cerebral infarctions in the deep perforator regions in a case of idiopathic hypereosinophilic syndrome].

A 61-year-old man was admitted to our hospital due to cerebral infarction in the pons and the right putamen. On admission (day 3 from symptom onset), laboratory testing showed a white blood cell count of 13,100/µl with hypereosinophilia of 3,734/µl. As deep vein thrombosis was detected on contrast-enhanced CT, we started anticoagulation therapy. There were no cardio-embolic sources, including right-to-left shunt, but eosinophil infiltration was found in biopsy specimens of the gastric mucosa. These findings allowed us to diagnose multiple perforator infarction due to idiopathic hypereosinophilic syndrome (idiopathic HES). After the administration of oral prednisolone was started on day 10, his hypereosinophilia rapidly improved, and no recurrence of deep perforator infarction occurred other than a symptomatic infarction in the left putamen at day 19. There are a few reports of idiopathic HES with multiple infarctions developing in deep perforator regions. The current case suggests that idiopathic HES could cause multiple cerebral infarction restricted to deep perforator areas.

Absence of pontine perforators in vertebrobasilar dolichoectasia on ultra-high resolution cone-beam computed tomography.

BACKGROUND: Vertebrobasilar dolichoectasia (VBDE) is a rare type of non-saccular intracranial aneurysm, with poor natural history and limited effective treatment options. Visualizing neurovascular microanatomy in patients with VBDE has not been previously reported, but may yield insight into the pathology, and provide important information for treatment planning. OBJECTIVE: To carry out a retrospective analysis of ultra-high resolution cone-beam computed tomography (UHR-CBCT) in patients with fusiform basilar aneurysms, visualizing neurovascular microanatomy of the posterior circulation with a special focus on the pontine perforators. METHODS: UHR-CBCT was performed in seven patients (mean age 59 years; two female) with a VBDE, and in 14 control patients with unrelated conditions. RESULTS: The mean maximum diameter of the fusiform vessel segment was 28 mm (range 19-36 mm), and the mean length of the segment was 39 mm (range 15-50 mm). In all patients with VBDE, UHR-CBCT demonstrated an absence of perforating arteries in the fusiform arterial segment and a mean of 3.7 perforators arising from the unaffected vessel segment. The network of interconnected superficial circumferential pontine arteries (brainstem vasocorona) were draping around the aneurysm sac. In controls, a mean of 3.6, 2.5, and 1.2 perforators were demonstrated arising from the distal, mid-, and proximal basilar artery, respectively. CONCLUSIONS: The absence of pontine perforators in the fusiform vessel segment of VBDE is counterbalanced by recruitment of collateral flow from pontine perforators arising from the unaffected segment of the basilar artery, as well as collaterals arising from the anterior inferior cerebellar artery/posterior inferior cerebellar artery and superior cerebellar artery. These alternative routes supply the superficial brainstem arteries (brainstem vasocorona) and sustain brainstem viability. Our findings might have implications for further treatment planning.

How I do it: Subtemporal transtentorial approach for cavernous malformation of the pons.

BACKGROUND: Removal of a pontine cavernous malformation requires sufficient exposure since any restriction on surgical freedom may lead to suboptimal visualization of the lesion, injury to the brainstem, and neurological catastrophe. METHODS: We describe and demonstrate the subtemporal transtentorial approach to a cavernous malformation of the upper pons, with emphasis on adequate surgical exposure while avoiding the need for extensive bone removal of the skull base. CONCLUSIONS: The meticulous technique is paramount to the successful removal of any brainstem cavernous malformation. Along with the surgical exposure, delicate handling of the malformation is demonstrated in the accompanying operative video.

Glutamate levels and perfusion in pons during migraine attacks: A 3T MRI study using proton spectroscopy and arterial spin labeling.

Migraine is a complex disorder, involving peripheral and central brain structures, where mechanisms and site of attack initiation are an unresolved puzzle. While abnormal pontine neuronal activation during migraine attacks has been reported, exact implication of this finding is unknown. Evidence suggests an important role of glutamate in migraine, implying a possible association of pontine hyperactivity to increased glutamate levels. Migraine without aura patients were scanned during attacks after calcitonin gene-related peptide and sildenafil in a double-blind, randomized, double-dummy, cross-over design, on two separate study days, by proton magnetic resonance spectroscopy and pseudo-continuous arterial spin labeling at 3T. Headache characteristics were recorded until 24 h after drug administrations. Twenty-six patients were scanned during migraine, yielding a total of 41 attacks. Cerebral blood flow increased in dorsolateral pons, ipsilateral to pain side during attacks, compared to outside attacks (13.6%, p = 0.009). Glutamate levels in the same area remained unchanged during attacks (p = 0.873), while total creatine levels increased (3.5%, p = 0.041). In conclusion, dorsolateral pontine activation during migraine was not associated with higher glutamate levels. However, the concurrently increased total creatine levels may suggest an altered energy metabolism, which should be investigated in future studies to elucidate the role of pons in acute migraine.

Recurrent Pontine Strokes in a Young Male.

A 34-year-old patient presented to the emergency department with recurrent neurologic symptoms of sudden onset. MRI showed white matter hyperintensities consistent with small vessel disease, predominantly in the pons. There were no known cardiovascular risk factors (CVRF) and extensive workup for vasculitis was negative. The preliminary diagnosis was small vessel primary central nervous system vasculitis, but immunosuppressive treatment did not stop a progression of the disease over 6 months. Repeated negative diagnostic workup for vasculitis, lack of response to therapy, young age, and predominant involvement of the pons were compatible with pontine autosomal dominant microangiopathy and leukoencephalopathy (PADMAL), which is a very rare monogenic cause of cerebral small vessel disease due to upregulation of collagen type-IV. Correspondingly, a COL4A1 mutation was found. Therapy was immediately stopped in favour of more strict adjustment of the CVRF including lowering of LDL < 70 mg/dl and extensive monitoring of blood-pressure.

Clinical Characteristics and Clinical Course of Body Lateropulsion in 47 Patients with Brainstem Infarctions.

BACKGROUND: In patients with lower lateral medullary infarction (LMI) located under the vestibular nucleus, proprioceptive impairment due to dorsal spinocerebellar tract (DSCT) is considered a pathological condition for body lateropulsion. In patients with brainstem infarction located at or above the level of the vestibular nucleus, other pathways, such as the crossed vestibulothalamic tract (CVTT), are considered responsible. RESEARCH QUESTION: The clinical course of body lateropulsion between each anatomical level of infarction remains unclear. Further, whether body lateropulsion refers to a static or a dynamic symptom also remains unclear. METHODS: We examined 47 patients who exhibited body lateropulsion and categorized them into four groups: lower LMI under the vestibular nucleus, LMI at the level of the vestibular nucleus, pontine infarction, and midbrain infarction. The patients' time to acquire static upright standing position and gait in a straight line were statistically analyzed by a log-rank test using the Kaplan-Meier method. RESULTS: Body lateropulsion in the static upright position was less frequent in the lower LMI group than in the other groups. SIGNIFICANCE: Lower LMI primarily affected body lateropulsion in gait. DSCT damage could affect ipsilateral hip joint or leg coordination, causing body lateropulsion in dynamic situation.

Diagnosis and treatment of pure arterial malformation: Three case reports and literature review.

RATIONALE: The incidence of pure arterial malformations is relatively low, and few cases have been reported. Only 2 cases with pure arterial malformation have been reported to receive surgery or endovascular treatment. PATIENT CONCERNS: We report 3 cases and review the relevant literatures. The head examinations of the patients suggested the presence of high-density shadows in front of the pons and midbrain, the dilation of the supraclinoid segment of the right internal carotid artery, and moyamoya in the left brain with an aneurysm-like expansion located on the left posterior communicating artery respectively. After admission, head digital subtraction angiography (DSA) was performed. DIAGNOSES: Digital subtraction angiography (DSA) for these 3 patients showed that the left posterior communicating artery, the supraclinoid segment of the right internal carotid artery, and the left posterior communicating artery appeared dilated, tortuous, and spirally elongated. In addition, the lesions in the latter 2 patients were accompanied with local aneurysmal changes. INTERVENTIONS: Two patients were given conservative treatment, and another patient was given endovascular treatment. A head DSA was reviewed 6 months after therapy. OUTCOMES: The prognosis status of the 3 patients was good. Two patients in the conservative treatment group showed no changes in the lesions on head DSA examination. The DSA examination of the third patient indicated that the vascular remodeling of the diseased vessels was good, the blood vessels were unobstructed, and the aneurysms had disappeared. LESSONS: Pure arterial malformations mostly occur in young women and may involve any blood vessels in the brain. It can be accompanied with local aneurysms and calcification. The patients are often given conservative treatment but need to be reviewed regularly. However, it is beneficial to give endovascular treatment to the patients with local aneurysms.

Prognostic evaluation of branch atheromatous disease in the pons using carotid artery ultrasonography.

BACKGROUND: Branch atheromatous disease is an ischemic stroke, involving occlusion or severe stenosis of the perforating artery, causing neurologic symptoms and serious sequelae. We aimed to investigate initial morphometric and hemodynamic characteristics of the vertebral artery immediately post-onset to predict lesion expanding. METHODS: This case-control study collected demographic, historical, and physical examination data from 44 patients with branch atheromatous disease in the pons at admission. The maximum ischemic pons area and stenosis rate in the basilar artery were calculated using magnetic resonance images. Diameter, velocity, and flow volume of the vertebral arteries were measured using carotid artery ultrasonography. Correlations between ischemic lesion extent and these parameters were investigated. RESULTS: Patients were assigned to groups of less (Group 1) or more (Group 2) than the median maximum ischemic area in the pons, calculated from magnetic resonance images (121.6 mm2). Modified Rankin scale scores were significantly worse in Group 2. Blood pressure and blood findings were similar between groups. Group 2 showed significantly higher basilar artery stenosis rates. Flow volume, velocity, peak systolic velocity, and end-diastolic velocity in the vertebral artery on both sides were significantly decreased in Group 2. CONCLUSIONS: Deteriorated vertebral artery hemodynamics caused a more extensive ischemic lesion in branch atheromatous disease in the pons. Evaluation of the vertebral using carotid artery ultrasonography in the acute phase may be useful for predicting disease progression.

Effects of injuries to descending motor pathways on restoration of gait in patients with pontine hemorrhage.

BACKGROUND AND PURPOSE: Gait disturbance due to injuries of the descending motor pathway, including corticospinal tract (CST), corticoreticular pathway (CRP), and medial and lateral vestibulospinal tracts (VSTs), are commonly encountered disabling sequelae of pontine hemorrhage. We investigated relations between changes in the CST, CRP, and medial and lateral VST and corresponding changes in gait function in patients with pontine hemorrhage. METHOD: Nine consecutive stroke patients with pontine hemorrhage, and 6 age-matched normal subjects were recruited. Four patients were allocated to group A (can't walk independently) and 5 to group B (can walk independently). Diffusion tensor imaging (DTI) data were acquired twice at acute to subacute stage and chronic stage after stroke onset. Diffusion tensor tractography (DTT) was used to reconstruct CST, CRP, medial and lateral VST. RESULT: The CRP shows a significantly different between groups A and B in both initial and follow up DTT (p > 0.05). In contrast, CST, medial VST and lateral VST did not show a significant difference (p > 0.05). Regarding DTI parameters of CRPs in group A, percentages of patients with fractional anisotropy (FA) and mean diffusivity (MD) values more than two standard deviation from normal were higher by follow up DTI than by initial DTI, however, the CRPs in group B only showed increased abnormal range of MD. CONCLUSIONS: The CST does not play an essential role in recovery of independent walking and vestibulospinal tracts may not crucially affect recovery of independent walking in patients with pontine hemorrhage. In contrast, and intact CRP or changes of the CRP integrity appear to be related to the recovery of gait function.

Intravenous thrombolysis for pure pontine infarcts caused by cardiac myxoma: a case report and literature review.

Purpose: Cardiac myxoma (CM) is a rare but important cause of ischemic stroke, and typically involves the middle cerebral artery and rarely affects the brainstem only. The safety and efficacy of intravenous thrombolysis (IVT) for CM-related acute cerebral embolism are not clear.Methods: We report a case of a 55-year-old woman who suffered a CM-related acute cerebral embolism presented with pure pontine infarcts and achieved a favorable prognosis by IVT with urokinase. We summarized the clinical data of this entity and performed a literature review of 21 previous reports of patients with CM-related acute cerebral embolism who were treated with IVT.Results: In combination with previous reports, we found that the majority of patients (81.8%) obtained improvements in symptoms after IVT, including 63.6% in remarkable clinical improvement. The total rate of IVT-induced intracerebral hemorrhage was 22.7% and all occurred within 36 h, including hemorrhagic infarction type 1 (4.5%) and parenchymal hematoma type 2 (18.2%). Most of the cases had relatively good outcomes and no case died due to IVT.Conclusion: Taken together, our findings support the use of IVT as an effective and safe tool for the ultra-early treatment of CM-related acute phase ischemic stroke.

Differential involvement of rubral branches in chronic capsular and pontine stroke.

BACKGROUND AND PURPOSE: Early studies have indicated that the cortico-rubro-spinal tracts play important roles in motor dysfunction after stroke. However, the differential involvement of the rubral branches in capsular and pontine stroke, and their associations with the motor impairment are still unknown. METHODS: The present study recruited 144 chronic stroke patients and 91 normal controls (NC) from three hospitals, including 102 cases with capsular stroke (CS) and 42 cases with pontine stroke (PS). The rubral branches, including bilateral corticorubral tracts (CRT), dentatorubral tracts (DRT), and rubrospinal tracts (RST), and the cortico-spinal tract (CST) were reconstructed based on the dataset of the Human Connectome Project. Group differences in diffusion scalars of each rubral branch were compared, and the associations between the diffusion measures of rubral branches and the Fugl-Meyer assessment (FMA) scores were tested. RESULTS: The bilateral CRT of the CS cases showed significantly lower factional anisotropy (FA) than in the NC. The bilateral DRT of the PS cases had lower FA than in the NC. Both CS and PS cases had significantly lower FA of the bilateral RST than the NC. Besides, the stroke patients demonstrated significantly lower FA in bilateral CSTs than the NC. Partial correlation analysis identified significantly positive correlations between the FA of the ipsilesional and CRT and the FMA scores in the CS group, and significantly positive correlations between the FA of the RST bilaterally and the FMA scores in the CS and PS groups. Furthermore, the association between RST integrity and FMA scores still survived after controlling for the effect of the CST. Finally, multiple regression modelling found that rubral tract FA explained 39.2% of the variance in FMA scores for CS patients, and 48.8% of the variance in FMA scores for PS patients. CONCLUSIONS: The bilateral rubral branches were differentially involved in the chronic capsular and pontine stroke, and the impairment severity of each rubral branch was dependent on lesion locations. The integrity of the rubral branches is related to motor impairment in both the chronic capsular and pontine stroke.

Seesaw nystagmus with internuclear ophthalmoplegia from bilateral dorsomedial pons and left thalamus infarction: a case report.

BACKGROUND: We describe for the first time the clinical features and mechanisms of a bilateral dorsomedial pons and left thalamus infarction with seesaw nystagmus and internuclear ophthalmoplegia. CASE PRESENTATION: A 62-year-old Chinese man was hospitalized for sudden-onset dizziness, diplopia, and gait disturbance. A neurological examination revealed seesaw nystagmus and internuclear ophthalmoplegia. Magnetic resonance imaging disclosed an acute infarction confined to the bilateral dorsomedial pons and left thalamus. Subsequently, 2 weeks of antithrombotic therapy led to an improvement in his symptoms. CONCLUSIONS: This case illustrates that the acute onset of seesaw nystagmus and internuclear ophthalmoplegia accompanied by risk factors for cerebrovascular diseases are highly suggestive of brainstem infarction.

"Basilar Web" Causing Basilar Branch Infarction.

We present a young patient with no vascular risk factors with a basilar branch infarction secondary to a shelf-like filling defect of the basilar artery. This defect was present and unchanged on repeat imaging and determined to be most consistent with a basilar web. Similar to carotid webs, a basilar web is believed to be an area of focal intimal fibroplasia that increases the risk of brainstem infarction. Focal fibroplasia of the posterior circulation should be considered when evaluating young adults with posterior circulation strokes of otherwise undetermined cause.