Transcranial parenhymal sonography in the diagnosis of Parkinson's disease

Abstract

Bacground/Aim. Modern ultrasound systems allow highresolution transcranial sonography (TCS) of the brain structures. Enlargement of the echogenic signal (hyperechogenicity) of the substantia nigra (SN) has been reported as a highly characteristic finding in idiopathic Parkinson's disease (PD) and is thought to reflect increased amounts of iron, bound to proteins other than ferritin, in the SN in the course of neurodegeneration. The aim of our study was to investigate the prevalence of the SN hyperechogenicity in PD patients, as well as its possible clinical correlates. Methods. The study comprised 103 consecutive PD patients and 50 healthy age-matched controls. For TCS examination a color-coded, phased array ultrasound system equipped with a 2.5 MHz transducer was used (ESAOTE Technos MP, Italia). The examination was performed through a preauricular acoustic bone window with a penetration depth of 16 cm and a dynamic range of 45-50 dB. The SN was identified within the butterfly shaped structure of the mesencephalic brainstem, with scanning from both temporal windows. Results. The SN hyperechogenicity was identified in 95 out of 103 examined PD patients (92%), which was marked in 60 (63%), and moderate in 35 patients (37%). Median SN echogenic size was larger contralateral to the clinically more affected side of the body. Unilateral SN hyperechogenicity was also found in 5 out of 50 healthy controls (10%). No ventricular enlargements were notified in our study. Conclusion. Our study demonstrated SN hyperechogenicity in more than 90% of PD patients. In adult subjects without neurological symptoms, the TCS finding of at least unilaterally marked SN hyperechogenicity indicates a subclinical functional impairment of the nigrostriatal dopaminergic system. .Uvod/Cilj. Moderni ultrazvucni sistemi su omogucili da se transkranijumskom sonografijom (TKS) mozdanog parenhima na zadovoljavajuci nacin prikazu strukture mozga. Kao veoma karakteristican nalaz u Parkinsonovoj bolesti (PB) opisano je povecanje ehogenog signala ("hiperehogenost") supstancije nigre (SN), jedra cija se neurodegeneracija smatra osnovnim patofizioloskim poremecajem ove bolesti. Cilj naseg rada je utvrdjivanje ucestalosti hiperehogenosti SN kod bolesnika sa PB i kod zdravih ispitanika, kao i utvrdjivanje mogucih klinickih korelacija takvog nalaza. Metode. U studiju su bila ukljucena 103 konsekutivna bolesnika sa PB i 50 zdravih ispitanika uporedive starosti. Transkranijumska sonografija je izvodjena koriscenjem kolor-kodiranog faznog ultrazvucnog sistema, transkranijumskom ultrazvucnom sondom od 2,5 MHz (ESAOTE Technos MP, Italija). Ultrazvucno skeniranje izvodjeno je kroz levi i desni temporalni kostani prozor, koristeci dubinu insonacije od 16 cm i dinamicki opseg 45-50 dB. Rezultati. Hiperehogenost SN utvrdjena je kod 95 od 103 ispitanih bolesnika obolelih od PB (92%): izrazena kod 60 (63%), a umerena kod 35 bolesnika (37%). Kod svih bolesnika sa asimetricnim ili jednostranim parkinsonizmom, hiperehogenost je bila iskljucivo prisutna ili znacajno izrazenija u kontralateralnoj SN. U kontrolnoj grupi, kod 50 zdravih ispitanika, hiperehogenost SN, po pravilu jednostrana, utvrdjena je kod 5 osoba (10%). Nije uoceno prosirenje komorskog sistema u ispitivanim grupama. Zakljucak. Hiperehogenost SN se metodom TKS konstatuje kod preko 90% bolesnika obolelih od PB. Kod zdravih odraslih osoba, TKS nalaz, makar i jednostrano izrazene hiperehogenosti SN, ukazuje na supklinicki, funkcionalni poremecaj nigrostrijatnog dopaminergickog sistema. .