Transcranial sonography as a diagnostic tool for Parkinson's disease: a pilot study in the city of Rio de Janeiro, Brazil

Abstract

In Brazil there is no systematic study on Transcranial Sonography (TCS), a neuroimaging method that depicts echogenic deep brain structures using ultrasound. Objective: To establish the percentage of subjects with permissive temporal windows and to address the ability of TCS of the substantia nigra (SN) to distinguish parkinsonian patients in a Brazilian sample. Method: We performed TCS using the Acuson X300 (Siemens, Germany) in 37 individuals: 23 with Parkinson's disease (PD) and 14 healthy controls. Results: 10.8% of subjects had insufficient temporal acoustic bone windows. SN echogenic areas were larger in patients (mean±SD, 0.31±0.08cm2 ) compared to controls (mean±SD, 0.17±0.02cm 2 ). TCS accurately identified 88.2% of PD patients. Conclusion: A large proportion of Brazilians seem to be eligible for TCS. An expressive number of PD patients could be diagnosed by TCS based on an expanded SN echogenic area. However, the current data is preliminary and must be corroborated by larger studies. Key words: diagnostic imaging, ultrasonography, Parkinson's disease.A Ultrassonografia transcraniana como método diagnóstico para a doença de Parkinson: um estudo piloto na cidade do Rio de Janeiro, Brasil RESUMO No Brasil não há estudos sistemáticos sobre a Ultrassonografia Transcraniana (USTC), modalidade de neuroimagem que visualiza estruturas ecogênicas profundas do parênquima cerebral utilizando ultrassom. Objetivo: Determinar a porcentagem de indivíduos com janelas ósseas adequadas e a capacidade da USTC da substância negra (SN) de discernir pacientes parkinsonianos em amostra brasileira. Método: USTC realizada com equipamento AcusonX300 (Siemens, Germany) em 37 indivíduos: 23 com doença de Parkinson (DP) e 14 controles saudáveis. Resultados: 10,8% dos participantes apresentaram janelas acústicas temporais inadequadas. As áreas de ecogenicidade da SN foram maiores nos pacientes (média±desvio padrão, 0,31±0,08 cm 2 ) do que nos controles (média±desvio padrão, 0,17±0,02 cm 2 ). A USTC identificou 88,2% dos pacientes com DP. Conclusão: Grande proporção de brasileiros parece ser elegível para a realização de USTC. Um número expressivo dos pacientes com DP poderia ser diagnosticado com base no aumento da área ecogênica da SN. Contudo, esses dados preliminares devem ser corroborados com amostra mais numerosa. Palavras-Chave: diagnóstico por imagem, ultrassonografia, doença de Parkinson.

Transcranial sonography in Parkinson's disease

“…This procedure has been considered sensitive and reliable in detecting abnormalities of the basal ganglia of the brain, such as degeneration of the SN in idiopathic PD, lesion of the lentiform nucleus in idiopathic dystonia, and degeneration of the SN and the caudate nucleus in Huntington's disease, among others. The method is also useful in the differential diagnosis of movement disorders and to clarify some of their pathophysiological mechanisms (12)(13)(14)(15)(16) .…”

Substantia Nigra Hyperechogenicity

“…Higher failure rates for transcranial sonography due to an insufficient bone window have been reported among Japanese, Taiwanese, South American, Australian, and South Korean populations. These differences may be caused by lower bone mineral density in these populations due to lower dietary calcium intake compared with Filipino and white populations 11 , 27 – 29 …”

“…These differences may be caused by lower bone mineral density in these populations due to lower dietary calcium intake compared with Filipino and white populations. 11,[27][28][29] Moreover, we examined whether repetitive measurements of the area of the substantia nigra increase diagnostic accuracy for PD. Indeed, we showed that repetitive measurements did increase the specificity and positive predictive value for diagnosis.…”

Transcranial sonography: Brazilian experience

“…We have read with special interest the article by Fernandes et al 1 entitled "Transcranial sonography as a diagnostic tool for Parkinson' s disease". These authors aimed to establish the percentage of subjects with adequated temporal bone windows for transcranial sonography (TCS) studies and also to revisit in a Brazilian sample the hypothesis that increased echogenic size of substantia nigra (SN) might distinguish Parkinson' s disease (PD) patients from healthy individuals.…”