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Friedreich's ataxia (FA) is a multisystemic degenerative disease, but the prevalence of restless legs syndrome (RLS) is unknown. FA patients might be particularly susceptible to develop RLS as FA presents with features commonly associated with RLS, e.g. multisystemic network dysfunction, peripheral neuropathy and disturbances in subcellular brain iron homeostasis. In this work, we assessed the following: (1) the prevalence of RLS; (2) the prevalence of sonographic hypoechogenicity of the substantia nigra (SN), which is known to be associated with idiopathic RLS; and (3) the relation between both in 28 FA patients. Thirty-two percent of the patients suffered from RLS, thus clearly exceeding the prevalence rate in the general population. SN hypoechogenicity was more frequent in FA patients (61%) compared to healthy controls (7%) and was significantly associated with RLS. However, as SN echogenicity also correlated inversely with disease severity, it seems to be related not only to RLS, but also to the neurodegenerative process in FA itself. The high prevalence of RLS in FA patients warrants specific assessment by neurologists involved in the care of FA patients as treatments are readily available. Similar to patients with idiopathic RLS, reduced SN echogenicity is a frequent finding in FA, possibly indicating regional changes in subcellular brain iron regulation in FA. [ABSTRACT FROM AUTHOR]

When scanning the size of the substantia nigra (SN), for example in Parkinson's disease, it is important to precisely locate its true anatomic location. The hypointense areas on T2-weighted magnetic resonance images (T2w) at the level of the upper midbrain are usually labeled as the SN. Recent studies showed that the line of demarcation between the SN and the crus cerebri (CC) in T2w images seems not to be clear. The purpose of our study was to evaluate the depiction of the SN and the CC on calculated R2 maps by analyzing the regional distribution of T2 values in both regions. In 36 healthy subjects, triple echo turbo spin echo were obtained at 1.5 T and R2 maps calculated. Proton density-weighted turbo spin echo images (PDw) were used as reference. The CC and SN were manually traced on PDw sections (CCP and SNP) and also the hyperintense areas on the R2 maps, suggestive of the SN (DT2). The obtained volumes were evaluated in terms of total size, intersections size, and residual areas, as well as the corresponding T2 values. DT2 corresponded to anterolateral parts of the SNP and showed an extension to anteromedial part of the CC. The intersections between DT2 and CCP and DT2 and SNP presented both decreased but different T2 values (102 ± 5 and 95 ± 4 ms). An exact differentiation of the SN from the CC is not possible on the basis of T2w images but rather on the basis of the underlying calculated T2 values from the triple echo sequence. [ABSTRACT FROM AUTHOR]

Abstract: Background and purpose: Using transcranial B-mode sonography (TCS), the first morphological marker for restless legs syndrome (RLS), hypoechogenicity of the substantia nigra (SN) has been found. The aim of this study was to validate SN hypoechogenicity as a morphological marker for RLS in a large patient cohort and to investigate further RLS-associated brain abnormalities using TCS. Methods: One hundred forty-three RLS patients (37 with symptomatic RLS) and 45 controls, matched for age and gender, underwent TCS by an experienced and independent rater who was blinded to clinical data. Results: The basal ganglia, ventricular system and cerebral lobes showed no RLS-specific abnormalities. SN hypoechogenicity correlated with a family history of RLS (p <0.001) and showed good sensitivity (82%), specificity (83%) and positive predictive value (94%). Red nucleus hyperechogenicity and brainstem raphe (BR) hypoechogenicity were more prevalent in RLS than in controls (both p <0.001) and correlated with reported periodic limb movements and depression, respectively (both p <0.001). Seventy-six percent of the patients (7% of controls) showed a co-occurrence of two or more sonographical abnormalities; 60% of symptomatic RLS patients showed the same sonographic features as the majority of RLS patients. Conclusions: TCS is a useful additional tool for diagnosing RLS and RLS-related disorders that demonstrate various brainstem abnormalities. [Copyright &y& Elsevier]

Summary: Background: Increased echogenicity of the substantia nigra (SN), as determined by transcranial sonography (TCS), is characteristic of idiopathic Parkinson''s disease (iPD). The results of initial retrospective studies indicate that this ultrasound sign is specific for iPD and can help to differentiate it from atypical parkinsonian syndromes (aPS); however, these early studies were done in patients with later disease stages and known clinical diagnosis. We aimed to determine the diagnostic value of TCS in the early stages of parkinsonian syndromes, when the clinical symptoms often do not enable a definite diagnosis to be made. Methods: 60 patients who presented with the first, but still unclear, clinical symptoms of parkinsonism had TCS in this prospective blinded study. Investigators were blinded to the results of the clinical investigations, the ultrasound findings, and the diagnosis at time of investigation. The patients were followed-up every 3 months for 1 year to assess and re-evaluate the clinical symptoms. The patients in whom a clinical diagnosis could not be made with certainty were investigated with raclopride PET or dopamine transporter single-photon emission computed tomography (SPECT), or both. Findings: A clinical diagnosis of parkinsonism could not be established at baseline in 38 patients. At 12 months, 39 patients were clinically categorised as having iPD. Compared with endpoint diagnosis, the sensitivity of TCS at baseline was 90%7% and the specificity was 82·4%; the positive predictive value of TCS for iPD was 92·9% and the classification accuracy was 88·3%. Interpretation: TCS is an easy to implement, non-invasive, and inexpensive technique that could help in the early differential diagnosis of parkinsonian syndromes. The routine use of TCS in the clinic could enable disease-specific therapy to be started earlier. Funding: Michael J Fox Foundation for Parkinson''s Research. [Copyright &y& Elsevier]

Abnormal substantia nigra morphology in healthy individuals, viewed with transcranial ultrasound, is a significant risk factor for Parkinson's disease. However, little is known about the functional consequences of this abnormality (termed 'hyperechogenicity') on movement. The aim of the current study was to investigate hand function in healthy older adults with (SN+) and without (SN−) substantia nigra hyperechogenicity during object manipulation. We hypothesised that SN+ subjects would exhibit increased grip force and a slower rate of force application compared to SN− subjects. Twenty-six healthy older adults (8 SN+ aged 58 ± 8 years, 18 SN− aged 57 ± 6 years) were asked to grip and lift a light-weight object with the dominant hand. Horizontal grip force, vertical lift force, acceleration, and first dorsal interosseus EMG were recorded during three trials. During the first trial, SN+ subjects exhibited a longer period between grip onset and lift onset (i.e. preload duration; 0.27 ± 0.25 s) than SN− subjects (0.13 ± 0.08 s; P = 0.046). They also exerted a greater downward force prior to lift off (−0.54 ± 0.42 N vs. −0.21 ± 0.12 N; P = 0.005) and used a greater grip force to lift the object (19.5 ± 7.0 N vs. 14.0 ± 4.3 N; P = 0.022) than SN− subjects. No between group differences were observed in subsequent trials. SN+ subjects exhibit impaired planning for manipulation of new objects. SN+ individuals over-estimate the grip force required, despite a longer contact period prior to lifting the object. The pattern of impairment observed in SN+ subjects shares similarities with de novo Parkinson's disease patients. [ABSTRACT FROM AUTHOR]

Identification of risk factors and prodromal markers for Parkinson's disease (PD) and the understanding of the point in time of first occurrence is essential for the early detection of incident PD. In this three-center longitudinal, observational study, we evaluated the specific risk for PD associated with single or combinations of risk factors and prodromal markers. In addition, we evaluated which risk factors and prodromal markers emerge at which time before the diagnosis of PD. Of the 1,847 at-baseline PD-free individuals ≥50 years, 1,260 underwent the 5-year follow-up assessment. There were 21 cases of incident PD during the study period. Enlarged hyperechogenic substantia nigra was the most frequent baseline sign in individuals developing PD after 3 years (80.0 %) and 5 years (85.7 %) compared to healthy controls (17.5 %) followed by the occurrence of mild parkinsonian signs and hyposmia. Evaluation of the signs at the first follow-up assessment showed that individuals developing PD after two additional years showed the same pattern of signs as individuals who developed PD 3 years after baseline assessment. [ABSTRACT FROM AUTHOR]

Transcranial sonography (TCS) is a valuable tool in the diagnosis of Parkinson’s disease (PD). However, substantia nigra hyperechogenicity (SN+) in TCS has been shown to be also evident in about 8–10% of healthy persons. Neuroimaging studies and slight motor deficits in subjects with SN+ indicate functional impairment of the nigrostriatal system associated with the ultrasound sign. We questioned, whether SN+ may also be associated with neuropsychological deficits and whether there is a relation to other PD premotor markers. Thirty-six subjects with SN+ and 34 control persons (SN−) older than 50 years were investigated. The delayed verbal memory recall (LogII) of subjects with SN+ was significantly reduced compared to the performance of the control group ( P = 0.02). Binary logistic regression analysis revealed that, besides UPDRS-III ( P < 0.001) and positive family history for PD ( P < 0.01), LogII ( P < 0.05) seems to be independently associated with SN+. [ABSTRACT FROM AUTHOR]