Plaque distribution of low-grade basilar artery atherosclerosis and its clinical relevance.

BACKGROUND: The underlying pathophysiology of BA distribution is unclear and intriguing. Using high-resolution magnetic resonance imaging (HR-MRI), we sought to explore the plaque distribution of low-grade basilar artery (BA) atherosclerosis and its clinical relevance. METHODS: We retrospectively analyzed the imaging and clinical data of 61 patients with low-grade atherosclerotic BA stenosis (<50%). On HR-MRI, the plaques were categorized based on the involvement of the ventral, dorsal, or lateral sides of BA wall. A culprit plaque was defined if it was on the same slice or neighboring slices of symptomatic pontine infarcts and played a probable causal role (dorsal plaques with median pontine infarcts or lateral plaques with ipsilateral pontine infarcts). The relationships between plaque distribution and clinical presentations were analyzed. RESULTS: Twenty-five symptomatic and thirty-six asymptomatic BAs with 752 HR-MRI image slices were studied. The average length of BA atherosclerosis plaques was 12.16 ± 5.61mm (10.30 ± 6.44mm in symptomatic and 13.46 ± 7.03mm in asymptomatic patients, p = 0.079). The plaque distribution was similar at ventral (29.0%), dorsal (37.6%) and lateral walls (33.1%). The BA plaques in symptomatic patients were more frequently located at the dorsal (42.5%) and lateral (41.2%) walls than at the ventral walls (16.1%; P < 0.05). Compared with symptomatic patients, asymptomatic patients more likely had their plaques distributed at the ventral walls (P = 0.022). Culprit plaques were observed in 85.0% (17/20) pontine infarcts in symptomatic patients and only 14.3% (2/14) silent pontine infarcts in asymptomatic patients (p < 0.001). CONCLUSIONS: Low-grade BA atherosclerosis has a long distribution and evenly involves ventral, dorsal and lateral walls. The plaques at dorsal and lateral walls are associated with symptomatic pontine infarcts but not with silent infarcts.

Intracranial tumors mimicking benign paroxysmal positional vertigo: A case series.

Background: A few intracranial lesions may present only with positional vertigo which are very easy to misdiagnose as benign paroxysmal positional vertigo (BPPV); the clinicians should pay more attention to this disease. Objectives: To analyze the clinical characteristics of 6 patients with intracranial tumors who only presented with positional vertigo to avoid misdiagnosing the disease. Material and methods: Six patients with intracranial tumors who only presented with positional vertigo treated in our clinic between May 2015 to May 2019 were reviewed, and the clinical symptoms, features of nystagmus, imaging presentation, and final diagnosis of the patients were evaluated. Results: All patients presented with positional vertigo and positional nystagmus induced by the changes in head position or posture, including one case with downbeating nystagmus in a positional test, two cases with left-beating nystagmus, one case with apogeotropic nystagmus in a roll test, one case with right-beating nystagmus, and one case with left-beating and upbeating nystagmus. Brain MRI showed the regions of the tumors were in the vermis of the cerebellum, the fourth ventricle, the lateral ventricle, and the cerebellar hemisphere.

Assessment of optic nerve and optic tract alterations in patients with orbital space-occupying lesions using probabilistic diffusion tractography.

AIM: To investigate the diffusion changes in both the optic nerve and optic tract in orbital space-occupying lesion patients with decreased visual acuity, and its clinical significance using probabilistic diffusion tractography (PDT). METHODS: Twenty patients with orbital space-occupying lesions and 25 age- and gender-matched healthy persons were included. All patients and controls underwent routine orbital magnetic resonance imaging and diffusion tensor imaging (DTI), using a 3.0T magnetic resonance scanner (Trio Tim Siemens). After the image data were preprocessed, each DTI parameters of the optic nerve and optic tract was obtained by PDT, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). The asymmetry index (AI) of each parameter was calculated. Compared the parameters of the affected side optic nerve and ipsilateral optic tract with the contralateral side by paired sample t-test; compared AI of parameters of optic nerve and optic tract between the patient group and the control group by independent sample t-test. Patients were divided into three subgroups according to the low vision grade standard of WHO, compared the FA and AI of FA between the three subgroups by single factor variance analysis. RESULTS: The affected side optic nerve presented significantly decreased FA, increased MD, AD, and RD values compared to the unaffected side (P<0.05). The AI of FA, MD, AD, and RD of optic nerve in the patients was significantly higher than that of the controls (P<0.05). The comparison results of the optic tract showed that there was no significant difference between the patient group and control group in terms of the bilateral optic tracts in patients (P>0.05). The AIs of the FA value of the optic nerve in the eyesight <0.1 subgroup was significantly higher than that in the other groups (P<0.05). CONCLUSION: FA, MD, AD, and RD of the affected side optic nerve of the orbital space-occupying lesions have significantly changed, the FA value is the most sensitive. The PDT could be a useful tool to provide valid quantitative markers of optic nerve injuries and evaluate the severity of orbital diseases, which other examinations cannot be acquired.