Utility of Magnetic Resonance Spectroscopy for the Progression of Neurological Symptoms in Lenticulostriate Artery Territory Infarction.

OBJECTIVES: The present study aimed to examine the effectiveness of proton magnetic resonance spectroscopy (1HMRS) in determining the progression of neurological symptoms resulting in acute ischemic stroke in patients with lenticulostriate artery (LSA) infarction. MATERIALS AND METHODS: 1HMRS was performed within 72 h after neurological symptom onset. Voxel of interest was placed in tissue that included the pyramidal tract and identified diffusion weighted echo planar spin-echo sequence (DWI) coronal images. Infarct volume in DWI was calculated using the ABC/2 method. 1HMRS data (tNAA, tCr, Glx, tCho, and Ins) were analyzed using LCModel. Progressive neurological symptoms were defined as an increase of 1 or more in the NIHSS score. Patients who underwent 1HMRS after progressive neurological symptoms were excluded. RESULTS: In total, 77 patients were enrolled. Of these, 19 patients had progressive neurological symptoms. The patients with progressive neurological symptoms were significantly more likely to be female and had higher tCho/tCr values, higher rates of axial slices ≥ 3 slices on DWI, higher infarct volume on DWI, higher maximum diameter of infarction of axial slice on DWI, and higher SBP on admission compared to those without. Multivariable logistic analysis revealed that higher tCho/tCr values were independently associated with progressive neurological symptoms after adjusting for age, sex, and initial DWI infarct volume (tCho/tCr per 0.01 increase, OR 1.26, 95% CI 1.03-1.52, P = 0.022). CONCLUSIONS: Increased tCho/tCr score were associated with progressive neurological symptoms in patients with LSA ischemic stroke. Quantitative evaluation of 1HMRS parameters may be useful for predicting the progression of neurological symptoms.

Characteristics of paramedian pontine arteries disease and its association with hemoglobinA1c.

Objectives: The association of branch atherosclerotic disease (BAD) and diabetes mellitus (DM) in the territory of posterior circulation is rarely discussed. Intracranial BAD was divided into two different types: paramedian pontine arteries (PPA) disease (PPD) and lenticulostriate arteries (LSA) disease. The goal of the study was to evaluate the clinical characteristics of PPD and its association with hemoglobinA1c (HbA1c) in China. Materials and Methods: Radiologically confirmed PPD was defined as an isolated unilateral infarction extending to the ventral surface of the pons. Small deep cerebral infarctions are usually caused by two different pathological changes of arteries: BAD and lipohyalinotic degeneration (LD). We compared the vascular risk factors between BAD and LD in PPA territory. A total of 159 stroke patients were analyzed (PPD, n = 75; LD, n = 84). Patients with PPD were also categorized into two groups according to follow-up modified Rankin Scale (FmRS) scores. Logistic regression analyses were used for the evaluation of independent risk factors of PPD and prognosis. Results: Comparison between PPD and LD revealed statistical significance in fasting glucose, HbA1c, estimated glomerular filtration rate (eGFR), and uric acid (p = .011, p = .005, p = .027, p = .018, respectively). Compared with LD, PPD was only related to HbA1c (p = .011) in logistic regression analysis. There were statistically significant differences between the two groups based on the stratification of FmRS scores in fasting glucose, HbA1c, homocysteine, eGFR, and the occurrence of DM. After multivariate analysis, only HbA1c was related with poor prognosis of PPD (p = .002). Conclusions: The subtypes and prognosis of small deep brain infarcts are significantly influenced by elevated HbA1c level in PPA territory. DM might play an important role in the pathogenesis of PPD.

Hyperdopaminergism in lenticulostriate stroke-related restless legs syndrome: an imaging study.

OBJECTIVE: The pathophysiology of restless legs syndrome (RLS) involves a dopaminergic dysregulation that remains poorly understood, with controversial data from the literature. Stroke-related RLS is a rare condition that involves primarily the basal ganglia, the paramedian pons, and the thalamus. Given these elements, we studied dopaminergic metabolism in patients with RLS secondary to lenticulostriate infarction using structural and nuclear imaging in the striatum ipsilateral to the infarction area, as compared to the contralateral side. We hypothesized that dopaminergic metabolism would be impaired in the striatum ipsilateral to stroke. METHODS: In this observational case-control study, we aimed to prospectively include patients with RLS secondary to lenticulo-striate infarction, for analyses of dopamine dysfunction ipsilateral to stroke as compared to the contralateral striatum and to a control population. Four patients fulfilled inclusion criteria with either de novo RLS or major exacerbation of RLS existing prior to stroke, and all four patients were included. Structural imaging was performed using brain magnetic resonance imaging, and the stroke-induced metabolic modifications were assessed by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). Dopamine reuptake via DAT was explored using 123I-FP-CIT SPECT. PET with 18F-FDOPA was used to evaluate the functional integrity of the presynaptic dopaminergic synthesis. RESULTS: The only structure damaged in all patients was the body of the caudate nucleus, right-sided for three and left-sided for one, as illustrated by magnetic resonance imaging. 18F-FDG PET showed a hypometabolism in the infarcted area, the ipsilateral thalamus, and the contralateral cerebellum. All patients displayed, in the ipsilateral putamen, increased dopaminergic tone. CONCLUSION: The present findings suggest that increased dopaminergic tone in the striatum may participate in the pathogenesis of RLS. These observations should encourage further research on RLS symptomatic with well-defined lesions as a promising way to further improve our understanding of its pathophysiology.

Correlation Between the Reduction in Lenticulostriate Arteries Caused by Hypertension and Changes in Brain Metabolism Detected With MRI.

OBJECTIVE: Hypertension can alter the vascular structure, mechanics, and function of small arteries and arterioles. It remains unknown whether microvascular changes are associated with brain metabolism. The purpose of this study was to analyze the correlation between the reduction in small arteries and changes in brain metabolism in patients with hypertension. SUBJECTS AND METHODS: The study population comprised 50 patients with hypertension and 50 volunteers without hypertension. The two groups underwent 3-T 3D time-of-flight MR angiography, and the numbers of lenticulostriate arteries (LSAs) were determined for both groups. Single-voxel proton MR spectroscopic data on the basal ganglia regions were also acquired. The ratios of N-acetylaspartate to creatine (NAA/Cr), myo-inositol to creatine (Mi/Cr), and choline to creatine (Cho/Cr) were measured. Statistical analysis was performed to evaluate the differences between the two groups with respect to metabolite ratios. RESULTS: The average total number of LSA stems on both sides in patients with hypertension was 5.12 ± 0.98 compared with 6.10 ± 0.95 in volunteers without hypertension (p < 0.0001). The NAA/Cr ratio decreased according to a reduction in the number of LSAs in the hypertension group, which was significantly reduced when the number of LSAs was 3 or fewer. CONCLUSION: Hypertension can lead to a statistically significant reduction in NAA/Cr ratio in the basal ganglia regions when the number of LSAs decreases to a certain extent. Reduced numbers of LSAs correlated with brain metabolism changes caused by hypertension, which can provide important insights for understanding the pathophysiologic mechanism of hypertension and may be valuable in evaluating this disease.