Differentiating PSP from MSA using MR planimetric measurements: a systematic review and meta-analysis

Abstract

Differential diagnosis of parkinsonian syndromes is considered one of the most challenging in neurology. Quantitative MR planimetric measurements were reported to discriminate between progressive supranuclear palsy (PSP) and non-PSP-parkinsonism. Several studies have used midbrain to pons ratio (M/P) and the Magnetic Resonance Parkinsonism Index (MRPI) in distinguishing PSP patients from those with Parkinson's disease. The current meta-analysis aimed to compare the performance of these measures in discriminating PSP from multiple system atrophy (MSA). A systematic MEDLINE review identified 59 out of 2984 studies allowing a calculation of sensitivity and specificity using the MRPI or M/P. Meta-analyses of results were carried out using random effects modelling. To assess study quality and risk of bias, the QUADAS-2 tool was used. Eight studies were suitable for analysis. The meta‐analysis showed a pooled sensitivity and specificity for the MRPI of PSP versus MSA of 79.2% (95% CI 72.7–84.4%) and 91.2% (95% CI 79.5–96.5%), and 84.1% (95% CI 77.2–89.2%) and 89.2% (95% CI 81.8–93.8%), respectively, for the M/P. The QUADAS-2 toolbox revealed a high risk of bias regarding the methodological quality of patient selection and index test, as all patients were seen in a specialized outpatient department without avoiding case control design and no predefined threshold was given regarding MRPI or M/P cut-offs. Planimetric brainstem measurements, in special the MRPI and M/P, yield high diagnostic accuracy for the discrimination of PSP from MSA. However, there is an urgent need for well-designed, prospective validation studies to ameliorate the concerns regarding the risk of bias.

Magnetic Resonance Planimetry in the Differential Diagnosis between Parkinson’s Disease and Progressive Supranuclear Palsy

“…Some studies, however, also included patients with the parkinsonian variant of MSA (MSA-P). A recent meta-analysis [ 69 ] summarized the current evidence regarding the accuracy of M/P and MRPI in distinguishing PSP (mainly PSP-RS) from the parkinsonian variant of MSA (MSA-P). These planimetric brainstem measurements yielded good diagnostic accuracy for the discrimination of PSP from MSA, with the M/P area ratio showing higher sensitivity and the MRPI showing higher specificity (MRPI: 79.2% pooled sensitivity and 91.2% pooled specificity; M/P: 84.1% pooled sensitivity and 89.2% pooled specificity).…”

[18F]FDG-PET zur Differenzialdiagnostik und Prognostik der neurodegenerativen Parkinson-Syndrome: Update 2022

“…Für die Diagnose der CBD konnte in der Metaanalyse dagegen kein unterscheidendes MRT-Merkmal identifiziert werden [56], was, wie oben diskutiert, ein großer Vorteil der [ 18 F]FDG-PET ist. Für die Trennung zwischen PSP und MSA mittels planimetrischer MRT ergab eine jüngste Metaanalyse eine der [ 18 F]FDG-PET vergleichbare Trennschärfe (gepoolte Sensitivität/Spezifität 79%-84%/89-91%) [57]. Studien zum direkten Vergleich von [ 18 Ein wichtiger Vorteil der [ 18 F]FDG-PET für den Einsatz in der klinischen Routine ist die Robustheit des Verfahrens sowohl in der Durchführung als auch in der Interpretation.…”

Morphometric imaging and quantitative susceptibility mapping as complementary tools in the diagnosis of parkinsonisms

“…Based on a large multicentre study, the MRPI value of 13.42 was proposed as the optimal cut‐off for early differential diagnosis between PSP and non‐PSP cases with an accuracy of 88.3% [22]. In contrast, both MRPI and midbrain to pons ratio showed suboptimal diagnostic value in distinguishing PSP from MSA patients [12, 23]. The MRPI is a time‐consuming index but was hypothesized to be less influenced by age compared to P/M [24], even though the influence of gender and age was not confirmed in a large cohort of healthy controls [25].…”

“…Based on a large multicentre study, the MRPI value of 13.42 was proposed as the optimal cut-off for early differential diagnosis between PSP and non-PSP cases with an accuracy of 88.3% [22]. In contrast, both MRPI and midbrain to pons ratio showed suboptimal diagnostic value in distinguishing PSP from MSA patients [12,23].…”