Síndromes parkinsonianas : diagnóstico diferencial por ressonância magnética e avaliação das alterações do sono

Abstract

We describe two studies, as follows: one concerns the role of cerebral morphometry as evaluated by magnetic resonance imaging (MRI) in the differential diagnosis of the parkinsonian syndromes; the other is about sleep alterations and the relationship with MRI changes in these syndromes. MRI measures can be useful for differential diagnosis between Parkinson disease (PD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA). The aim of this study was to evaluate the diagnostic value of structural anatomic changes identified by MRI in the differential diagnosis of these syndromes. We studied 21 cases with PD, 11 with MSA-c, 8 with MSA-p, 20 with PSP and 12 controls. Midbrain area (Ams), Pons area (Apn), middle cerebellar peduncle (MCP) and superior cerebellar peduncle (SCP) width were measured using MRI. Multiple comparisons were made between PD, MSA-p, MSA-c and PSP and we show that Apn, MCP and SCP width morphometry dimensions have clear cut differences in these syndromes. The Ams and SCP were the most predictive measures of PSP. A Midbrain area below 105 mm2 and SCP less than 3 mm showed a major probability for this diagnosis (sensitivity of 95.0 and 80.0%, respectively). For the group of MSA-c patients, an Apn area below 315mm2 showed good specificity and positive predictive value (93.8% and 72.7%, respectively). In conclusion, we demonstrate that dimensions and cut off values obtained from routine MRI can differentiate between PD, PSP and MSA-c with good sensitivity, specificity and accuracy. Despite common reports in PD, in other parkinsonian syndromes, sleep disturbances have been less frequently described. We compare sleep disturbances in patients with PD, MSA and PSP and analyze associations with brain MRI morphometry. This was a cross-sectional study of 16 PD cases, 13 MSA and 14 PSP. Sleep disturbances were evaluated by Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index (PSQI), Restless Legs Scale and Berlin questionnaire. Apn, Ams, MCP width, and SCP width were measured using MRI. Poor quality sleep, risk of obstructive sleep apnea (OSA) and restless legs syndrome (RLS) were detected in all groups. Patients with MSA showed higher risk of OSA and less frequent RLS. In MSA, a correlation between PSQI scores and Hoehn and Yahr stage was observed (p<0.05). In PSP, RLS was frequent (57%) and related with reduced sleep duration and efficiency. In PD, excessive daytime sleepiness was related to atrophy of the MCP (p= 0.01). High risk of OSA was common and prominent in MSA cases. RLS was more frequent in PD and PSP, and in PSP, was associated with reduced sleep efficiency and sleep duration. In conclusion, the morphometric analysis of PD patients with excessive daytime sleepiness showed more atrophy of MCP (PD with excessive daytime sleepiness MCP= 16.08±0.93; PD without excessive daytime sleepiness MCP=17.82±0.80 p= 0.01) suggesting widespread degeneration of brainstem sleep structures on the basis of sleep abnormalities in these patients.