Distinguishing Parkinson's disease and essential tremor with transcranial sonography.

OBJECTIVES: Until today there is no reliable test that can clearly distinguish Parkinson's disease (PD) from the essential tremor (ET). Our aim was to determine the usefulness of the transcranial sonography (TCS) in the differential diagnosis of the PD and ET as well as the interobserver reliability for this method. METHODS: Transcranial sonography of substantia nigra and clinical examination were performed on 80 PD patients, 30 ET patients, and 80 matched controls by two independent physicians. RESULTS: Bilateral SN hyperechogenicity over the margin of 0.20 cm(2) was found in 91% of PD patients, 10% of healthy subjects, and in 13% patients with ET. Interobserver agreement for this method was significant (Student's t-test, P = 1.000). CONCLUSIONS: Substantia nigra hyperechogenicity on TCS is a highly specific finding of PD, where in healthy individuals or in ET patients, it might correspond to an increased risk of developing PD later in life or might also be because of the impairment of nearby area of nucleus ruber in ET patients, as suggested by positron emission tomography studies. TCS may serve as a practical and sufficiently sensitive neuroimaging tool in PD diagnoses and in distinguishing it from ET; its repeatability and accuracy might add to its practical value.

Pineal gland cyst evaluated by transcranial sonography.

Transcranial sonography (TCS) has never been used in the evaluation of morphology of pineal gland. The aim of the study was to assess the possibility of TCS to distinguish normal from cystic pineal gland and to correlate its size with magnetic resonance imaging (MRI) at the first examination and during follow-up. Sixty patients with previously made MRI of the brain were evaluated by two independent observers using TCS, blinded to the results of the MRI. Inappropriate bone window limited TCS examination in seven patients. All 14 pineal gland cysts (PGC) seen on MRI were detected by both observers using TCS. Control group consisted of 39 healthy examinees. No statistically significant difference has been found between: PGC size measured by first and second observer by TCS (P = 0.425), PGC size measured by TCS and MRI (first observer, P = 0.353; second observer, P = 0.425), size of the pineal gland measured by TCS and MRI in control group (first observer, P = 0.497; second observer, P = 0.370) or interobserver variability in control group (P = 0.373). The MRI and TCS follow-up of ten patients after six months did not show any difference in size of PGC. TCS can be used as a method in detection, measurement and follow-up of PGC.