Multiparametric analysis from dynamic susceptibility contrast-enhanced perfusion MRI to evaluate malignant brain tumors.

BACKGROUND AND PURPOSE: Dynamic susceptibility contrast-enhanced (DSC) MR perfusion is a valuable technique for distinguishing brain tumors. Diagnostic potential of measurable parameters derived from preload leakage-corrected-DSC-MRI remains somewhat underexplored. This study aimed to evaluate these parameters for differentiating primary CNS lymphoma (PCNSL), glioblastoma, and metastasis. METHODS: Thirty-nine patients with pathologically proven PCNSL (n = 14), glioblastoma (n = 14), and metastasis (n = 11) were analyzed. Five DSC parameters-relative CBV (rCBV), percentage of signal recovery (PSR), downward slope (DS), upward slope (US), and first-pass slope ratio-were derived from tumor-enhancing areas. Diagnostic performance was assessed using receiver operating characteristic curve analysis. RESULTS: RCBV was higher in metastasis (4.58; interquartile range [IQR]: 2.54) and glioblastoma (3.98; IQR: 1.87), compared with PCNSL (1.46; IQR: 0.29; p = .00006 for both). rCBV better distinguished metastasis and glioblastoma from PCNSL, with an area under the curve (AUC) of 0.97 and 0.99, respectively. PSR was higher in PCNSL (88.11; IQR: 21.21) than metastases (58.30; IQR: 22.28; p = .0002), while glioblastoma (74.54; IQR: 21.23) presented almost significant trend-level differences compared to the others (p≈.05). AUCs were 0.79 (PCNSL vs. glioblastoma), 0.91 (PCNSL vs. metastasis), and 0.78 (glioblastoma vs. metastasis). DS and US parameters were statistically significant between glioblastoma (-109.92; IQR: 152.71 and 59.06; IQR: 52.87) and PCNSL (-47.36; IQR: 44.30 and 21.68; IQR: 16.85), presenting AUCs of 0.86 and 0.87. CONCLUSION: Metastasis and glioblastoma can be better differentiated from PCNSL through rCBV. PSR demonstrated higher differential performance compared to the other parameters and seemed useful, allowing a proper distinction among all, particularly between metastasis and glioblastoma, where rCBV failed. Finally, DS and US were only helpful in differentiating glioblastoma from PCNSL.

Recurrent Transient Ischemic Attacks and Stroke Due to Carotid Dissection During Air Travel: A Case Report.

Carotid artery dissection causes 2.5% of ischemic acute strokes and is more common in younger rather than older patients. Extracranial lesions often manifest as transient and reversible neurological deficits until a stroke occurs. In this case, we describe a 60-year-old male patient with no known cardiovascular risk factors who experienced three transient ischemic attacks (TIAs) in four days while traveling in Portugal. At the emergency department, he was treated for an occipital headache associated with nausea and two episodes of decreased left upper-limb muscle strength lasting two to three minutes with spontaneous recovery. He requested discharge against medical advice so that he could travel home. During the return flight, he had a severe right parietal headache followed by decreased muscle strength in the left arm. After an emergency landing in Lisbon, he was referred to the local emergency department, where his neurological examination revealed preferential gaze to the right exceeding the midline, left homonymous hemianopsia, minor left central facial paresis, and spastic left brachial paresis. On the National Institutes of Health Stroke Scale, he scored 7. A head CT was performed, showing no acute vascular lesions (i.e., Alberta Stroke Program Early CT Score of 10). However, an image compatible with dissection was identified on CT angiography of the head and neck and confirmed by digital subtraction angiography. The patient underwent balloon angioplasty and placement of three stents in the right internal carotid artery with vascular permeabilization. This case highlights how prolonged and incorrect cervical posture and microtrauma secondary to aircraft turbulence may be associated with carotid artery dissection in predisposed individuals. The Aerospace Medical Association guidelines advocate that patients with a recent acute neurological event should avoid air travel until clinical stability is assured. As TIA is considered a harbinger of stroke, patients should be properly evaluated and avoid air travel for at least two days after the event.

Brain imaging findings in CLCN2-related leukoencephalopathy.

CLCN2-related leukoencephalopathy is a rare autosomal-recessive disease caused by a loss-of-function mutation in the ClC-2 chloride channel, which is fundamental in ion and water brain homeostasis. With only 31 cases published in the literature, its precise pathophysiology is uncertain, clinical manifestations are nonspecific and little is known in terms of prognosis. Neuroimaging plays a fundamental role in the identification of CLCN2-related leukoencephalopathy, which has a typical magnetic resonance imaging pattern that, when recognized, should promote proper genetic study for diagnostic confirmation. We report a paediatric clinical case of CLCN2-related leukoencephalopathy with genetically verified c.1709G > A p(Trp570*) mutation, highlighting typical neuroimaging findings and the importance of imaging in the diagnostic approach.

Olfactory Cleft Length: A Possible Risk Factor for Persistent Post-COVID-19 Olfactory Dysfunction.

INTRODUCTION: To date, little is known about predisposing factors for persistent COVID-19-induced olfactory dysfunction (pCIOD). The objective was to determine whether olfactory cleft (OC) measurements associate with pCIOD risk. MATERIAL AND METHODS: Three subgroups were recruited: group A included patients with pCIOD, group B included patients without olfactory dysfunction following SARS-CoV-2 infection (ntCIOD), and group C consisted in controls without past history of SARS-CoV-2 infection (noCOVID-19). Olfactory perception threshold (OPT) and visual analog scale for olfactory impairment (VAS-olf) were obtained. OC measurements were obtained through computed tomography scans. Results were subsequently compared. RESULTS: A total of 55 patients with a mean age of 39 ± 10 years were included. OPT was significantly lower in pCIOD patients (group A: 4.2 ± 2.1 vs. group B: 12.3 ± 1.8 and group C: 12.2 ± 1.5, p < 0.001). VAS-olf was significantly higher in pCIOD (group A: 6 ± 2.6 vs. group B: 1.7 ± 1.6 and group C: 1.6 ± 1.5, p < 0.001). OC length was significantly higher in group A (42.8 ± 4.6) compared to group B (39.7 ± 3.4, p = 0.047) and C (39.8 ± 4, p = 0.037). The odd of pCIOD occurring after COVID-19 infection increased by 21% (95% CI [0.981, 1.495]) for a one unit (mm) increase in OC length. The odd of pCIOD occurring was 6.9 times higher when OC length >40 mm. CONCLUSION: Longer OC may be a predisposing factor for pCIOD. This study is expected to encourage further research on OC morphology and its impact on olfactory disorders.