Magnetic Resonance Imaging Cerebrospinal Fluid Hydrodynamics in Patients with Meningitis

Abstract

Objective: The objective of the study was to evaluate the cerebrospinal fluid (CSF) flow alterations in meningitis using phase-contrast magnetic resonance imaging (PCMRI). Materials and Methods: Fifty patients with clinically confirmed or strongly suspected infectious meningitis and 20 controls were evaluated with MRI. Quantitative CSF analysis was performed at the level of cerebral aqueduct using cardiac-gated PCMRI. Velocity encoding (Venc) was kept at 20 cm/s. Patients were subdivided into Group I (patients with hydrocephalus [n = 21]) and Group II (patients without hydrocephalus [n = 29]). Results: The mean peak velocity and stroke volume in controls were 2.49 ± 0.86 cm/s and 13.23 ± 6.84 µl and in patients were 2.85 ± 2.90 cm/s and 16.30 ± 20.02 µl, respectively. A wide variation of flow parameters was noted in meningitis irrespective of the degree of ventricular dilatation. A significant difference in peak velocity and stroke volume was noted in Group II as compared to controls. Viral meningitis showed milder alteration of CSF flow dynamics as compared to bacterial and tuberculous etiologies. At a cutoff value of 3.57 cm/s in peak CSF velocity, the specificity was 100% and sensitivity was 22.7% to differentiate between viral and non-viral meningitis. Conclusion: Alteration of CSF flow dynamics on PCMRI can improve segregation of patients into viral and non- viral etiologies, especially in those in whom contrast is contraindicated or not recommended. This may aid in institution of appropriate clinical treatment.

Etiology, Clinical Phenotypes, Epidemiological Correlates, Laboratory Biomarkers and Diagnostic Challenges of Pediatric Viral Meningitis: Descriptive Review

“…Generally, neuroimaging was proved of little diagnostic value for PVM in circumstances other than confirmatory purposes because non-specific findings were obtained. However, recently the MRI technique was used to elucidate features that can distinguish meningitis of viral and non-viral etiologies (185).…”

Cerebrospinal Fluid Flow Parameters in Normal Subjects above 40 Years of Age

“… 10 Neither is it clear what was the age range of their normal subjects, making it really difficult to use it as a reference for normal data. Sharma et al have given the value of only peak flow velocity in 13 subjects with an average age of 64.9 years 11 and Lakhera et al have given peak velocity and SV in 20 normal subjects 1 but have not elaborated the age range or average age of these normal subjects. Hence, these studies are difficult to use as a baseline as they have a very small sample size and have studied very few parameters.…”

“… 12 Lakhera et al used CSF flow dynamics to distinguish viral from nonviral meningitis which was quite helpful in cases where contrast could not be administered. 1 CSF is a multifunctional entity, not only in diagnosing central nervous system disorders but also in further clinical monitoring and prognosis after treatment. 13 Hussein et al evaluated the prognostic value of MRI-CSF flowmetry for shunt responsiveness in patients with idiopathic normal pressure hydrocephalus (iNPH) and its usefulness as a predictor of post-CSF diversion favorable outcome.…”

“…The region of interest (ROI) was kept at the cerebral aqueduct in crosssection such that it covered the entire aqueduct and no extra tissue was included in it (►Fig. 1) The inbuilt software calculated flow-time and velocity-time graphs and calculated PSV, PDV, SF, and DF, while SV was calculated by taking average of systolic and DFs. Mean (with standard deviation) and median (with interquartile range) were calculated for continuous data.…”

“…An increase in intracranial pressure can cause characteristic symptoms of hydrocephalus, though they also may occur with normal pressure. 1 CSF flows in oscillatory motion resulting from cardiac pulsations. Cardiac systole transmits pressure wave to intracranial arteries and capillaries causing caudal flow of CSF (CSF systole) through the ventricular system, basal cisterns, and foramen magnum into the cervical subarachnoid space.…”