Transcranial sonography in atypical parkinsonism: How reliable is it in real clinical practice? A multicentre comprehensive study

A New MRI Measure to Early Differentiate Progressive Supranuclear Palsy From De Novo Parkinson's Disease in Clinical Practice: An International Study

“…In accordance with previous reports, 6‐10 our results showed that the enlargement of the third ventricle was a common finding in PSP but not in PD. In addition, we also demonstrated that disease progression did not influence the third ventricle width in PD patients because the 3 rd V/ID ratio did not vary over the 4‐year follow‐up despite the disease progression, as reflected by the increase in clinical scores.…”

“…There is evidence that the enlargement of the third ventricle is a common radiological feature in PSP, supporting the hypothesis that the 3 rd V width measurement may help to differentiate PSP from PD. [6][7][8][9][10] Several studies have investigated the third ventricle size in combination with substantia nigra hyperechogenicity in PSP and PD patients using transcranial sonography, showing good results in PD diagnosis but low sensitivity and PPV in distinguishing between these 2 diseases. 7,8 Limitations to the usefulness of transcranial sonography as a biomarker are its heavy dependence on the examiner's experience and technical skills and the low sensitivity in differentiating between PD and PSP.…”

“…Several studies have also demonstrated that enlargement of the third ventricle (3 rd V) commonly occurs in atypical parkinsonism, above all PSP, compared with PD patients and control subjects. [6][7][8][9][10] Recently, a new version of MRPI including third ventricle width measurement, showed excellent diagnostic performance in distinguishing different PSP phenotypes from PD 6 and in predicting the appearance of a PSP phenotype in patients with an initial diagnosis of PD. 3 MRPI and MRPI 2.0, however, require specific image reconstruction and expertise and are suited to research rather than routine clinical practice.…”

“…A recent review from the Movement Disorder Society–endorsed Study Group 5 reported that the Magnetic Resonance Parkinsonism Index (MRPI) is one of the most reliable imaging biomarkers for PSP, supporting clinical diagnoses in these patients. Several studies have also demonstrated that enlargement of the third ventricle (3 rd V) commonly occurs in atypical parkinsonism, above all PSP, compared with PD patients and control subjects 6‐10 . Recently, a new version of MRPI including third ventricle width measurement, showed excellent diagnostic performance in distinguishing different PSP phenotypes from PD 6 and in predicting the appearance of a PSP phenotype in patients with an initial diagnosis of PD 3 .…”

Early autonomic and cognitive dysfunction in PD, DLB and MSA: blurring the boundaries between α-synucleinopathies

“…In contrast, substantia nigra hyperechogenicity in transcranial sonography (TCS) has proven useful for PD diagnosis offering good diagnostic reliability at a low cost beyond the research setting. However, conflicting data exist regarding the capacity of TCS to distinguish atypical parkinsonisms from PD, a missing temporal bone window is present in 10-20% of subjects, and it is heavily dependent on the investigator's experience and technical skills [58]. Additionally, supine resting plasma norepinephrine levels seem able to predict whether the DLB/ PD or MSA will eventually develop in patients with a diagnosis of pure autonomic failure (PAF), tending to be lower in PAF patients who phenoconverted to PD/DLB and higher in those that phenoconverted to probable MSA [59].…”