Abstract Details

Title Radiologic Overlap between Idiopathic Normal Pressure Hydrocephalus and the Parkinsonian Syndromes

Topic Movement Disorders

Presentation(s) P3 - Poster Session 3 (12:00 PM-1:00 PM)

Poster/Presentation
Number 3-011

Objective To explore the radiologic overlap between the neurodegenerative parkinsonian syndromes and idiopathic normal pressure hydrocephalus (iNPH) by examining the ventriculomegaly found in both.

Background iNPH is a syndrome of late adulthood manifesting with gait disturbance, dementia and incontinence. Ventriculomegaly is the hallmark of iNPH, but it also results from neurodegeneration of the deep cerebral structures (ex vacuo). As such, iNPH resembles the parkinsonian syndromes. Ventriculomegaly can be defined as a ratio comparing the maximal diameter between the frontal horns of the lateral ventricles to that of the internal skull (Evans’ index) of greater than 0.30.

Design/Methods We retrospectively analyzed the brain CTs and MRIs of 160 randomly selected patients with neurodegenerative parkinsonian syndromes. All studies were interpreted clinically by neuroradiologists. We applied the Evans’ index to obtain a quantitative measure of lateral ventricles size.

Results Ventriculomegaly is present in 43.3% when applying the Evans’ index (quantitative) and 26.9% when interpreted by a neuroradiologist (qualitative). Qualitative radiologic findings consistent with iNPH were reported in 7.5% (12 of 160). Lateral ventricles size was larger in the atypical parkinsonian syndromes, and particularly in progressive supranuclear palsy (PSP), as compared to Parkinson’s disease (p=0.007). 1.9% had undergone a diagnostic LP or VPS.

Conclusions

We found that in our patients with neurodegenerative parkinsonian syndromes, ventriculomegaly is a common radiological sign and one which is underreported by neuroradiologists. In spite of this underreporting, imaging-based findings consistent with iNPH is 2.6 to 75-fold more common in our patient cohort as compared individuals of a similar age group.

Based on these observations, we propose that the resemblance between the ventriculomegaly ex vacuo of the parkinsonian syndromes and the ventriculomegaly of iNPH can lead to over-diagnosing iNPH in this group of diseases. Parkinsonian syndromes, and in particular PSP, should be critically considered in the differential diagnoses of iNPH.

Authors/Disclosures
Christina Martin Schaff, MD PRESENTER	Dr. Martin Schaff has nothing to disclose.
Guy Schwartz, MD (Stony Brook University Hospital)	Dr. Schwartz has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Supernus. Dr. Schwartz has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Aaronson Rappaport Feinstein & Deutsch, LLP.
	No disclosure on file

��ɫ��

��ɫ��