Abstract

BackgroundTranscranial duplex sonography (TCD) of the substantia nigra has emerged as a promising, non-invasive tool to diagnose idiopathic Parkinson's disease (IPD). However, its diagnostic accuracy in patients with undefined parkinsonism remains to be determined.In this study we determined the predictive value of TCD for the clinical diagnosis in undiagnosed parkinsonian syndromes. Additionally we compared the predictive value of TCD with that of presynaptic and postsynaptic single photon emission computer tomography (SPECT) scans.MethodsWe studied 82 patients with an unclassified parkinsonian syndrome. All 82 patients were subjected to a TCD, 59 of them underwent a presynaptic SPECT scans and 32 underwent a postsynaptic SPECT scan.We determined the diagnostic accuracy of TCD and SPECT scans in differentiating:1) IPD patients from patients without nigrostriatal degeneration and 2) IPD patients from patients with atypical parkinsonian syndromes (APS).To compare the diagnostic accuracy of TCD and SPECT scans, we used the clinical diagnosis after follow-up according to generally accepted clinical criteria as the gold standard. This clinical diagnosis was determined by a movement disorder specialist.3) Finally, we ascertained the predictive value of the TCD for the SPECT result.ResultsThe clinical diagnoses after follow-up resulted in 51 cases of IPD, 7 patients with APS and 17 patients without nigrostriatal degeneration. In total 7 patients remained undiagnosed.1) The accuracy of TCD, assessed by sensitivity and specificity, to differentiate IPD patients from patients without nigrostriatal degeneration was 50% and 82% respectively.For the presynaptic SPECT scans sensitivity was 97% and specificity 100%.2) In differentiating IPD patients from APS patients, the sensitivity and specificity of TCD was 50% and 43% respectively. For presynaptic SPECT scans this was 97% and 0%. For the postsynaptic SPECT scans the sensitivity was 75% and the specificity 81%.3) The positive predictive value (PPV) of an abnormal TCD for an abnormal presynaptic SPECT scan was 88%.ConclusionPresynaptic SPECT scanning has a higher predictive value for the clinical diagnosis than TCD. However, since the PPV of an abnormal TCD for parkinsonism with nigrostriatal degeneration is high, TCD might be used as screening tool, before ordering a presynaptic SPECT.

Highlights

  • Transcranial duplex sonography (TCD) of the substantia nigra has emerged as a promising, non-invasive tool to diagnose idiopathic Parkinson's disease (IPD)

  • Since the positive predictive value (PPV) of an abnormal TCD for parkinsonism with nigrostriatal degeneration is high, TCD might be used as screening tool, before ordering a presynaptic single photon emission computer tomography (SPECT)

  • We investigated the similarity in results between substantia nigra (SN)-TCD and presynaptic SPECT

Read more

Summary

Introduction

Transcranial duplex sonography (TCD) of the substantia nigra has emerged as a promising, non-invasive tool to diagnose idiopathic Parkinson's disease (IPD). In this study we determined the predictive value of TCD for the clinical diagnosis in undiagnosed parkinsonian syndromes. The diagnosis of idiopathic Parkinson's disease (IPD) is based on clinical criteria. The differentiation between IPD and other parkinsonian syndromes can be difficult, especially in the early stages of the disease. Diseases which might resemble early-stage IPD are Multiple System Atrophy (MSA), Progressive Supranuclear Palsy (PSP), Diffuse Lewy Body Disease (DLBD), corticobasal degeneration (CBD), and vascular parkinsonism (VP), drug induced parkinsonism (DIP) and essential tremor (ET). Clinicopathological studies show that 2– 25% of the patients with IPD are classified incorrectly in the final stage of their disease, even by specialists in movement disorders [2,3,4,5,6]. Because the prognosis and medical treatment differ between various parkinsonian syndromes, an accurate and early diagnosis is essential for optimal treatment and counselling

Methods
Results
Discussion
Conclusion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.