Is nocturnal eating in restless legs syndrome linked to a specific psychopathological profile? A pilot study.

The purpose of the study was to evaluate psychological comorbidity in drug-naive or drug-free primary restless legs syndrome (p-RLS) patients with nocturnal eating disorder (NED), and to analyze the association of comorbid p-RLS and NED with obsessive-compulsive, mood and anxiety symptoms, and personality. Participants comprised 20 consecutive female outpatients with p-RLS, 10 without NED and 10 with NED, and 10 female controls matched for age. Both patients and controls were evaluated by the Hamilton Depression and the Anxiety Rating Scales, the State-Trait Anxiety Inventory, the Maudsley Obsessive Compulsive Inventory and the temperament and character inventory-revised. Compared to controls, p-RLS patients without and with NED had higher trait anxiety and current anxiety and obsessive-compulsive symptoms. p-RLS patients with NED also had significantly higher doubting compared to p-RLS patients without NED. Furthermore, groups differed for harm avoidance (HA), with p-RLS patients with and without NED having higher scores than controls. Untreated p-RLS patients, particularly those with nocturnal eating, report anxiety and obsessive-compulsive symptoms, perceive stressful situations as dangerous and threatening and tend to respond with anxiety to such situations. They have higher tendency to respond intensely to aversive stimuli, inhibiting behavior to avoid punishment, novelty, and frustrative omission of expected rewards. We hypothesize that higher levels of HA, a biologically determined personality trait, might constitute a diathesis predisposing individuals to display obsessive-compulsive symptoms, namely increasingly severe compulsive nocturnal eating.

Low brain iron content in idiopathic restless legs syndrome patients detected by phase imaging.

BACKGROUND: The objective of this study was to use phase imaging to evaluate brain iron content in patients with idiopathic restless legs syndrome (RLS). METHODS: Fifteen RLS patients and 15 healthy controls were studied using gradient-echo imaging. Phase analysis was performed on localized brain regions of interest selected on phase maps, sensitive to paramagnetic tissue. Differences between the 2 subject groups were evaluated using ANCOVA including age as a covariate. RESULTS: Significantly higher phase values were present in the RLS patients compared with healthy controls at the level of the substantia nigra, thalamus, putamen, and pallidum, indicating reduced iron content in several regions of the brain of the patients. CONCLUSIONS: We have used MRI phase analysis to study brain iron content in idiopathic RLS in vivo for the first time. Our results support the hypothesis of reduced brain iron content in RLS patients, which may have an important role in the pathophysiology of the disorder.

Abnormal medial thalamic metabolism in patients with idiopathic restless legs syndrome.

Pathophysiology of restless legs syndrome is poorly understood. A role of the thalamus, specifically of its medial portion which is a part of the limbic system, was suggested by functional magnetic resonance imaging and positron emission tomography studies. The aim of this study was to evaluate medial thalamus metabolism and structural integrity in patients with idiopathic restless legs syndrome using a multimodal magnetic resonance approach, including proton magnetic resonance spectroscopy, diffusion tensor imaging, voxel-based morphometry and volumetric and shape analysis. Twenty-three patients and 19 healthy controls were studied in a 1.5 T system. Single voxel proton magnetic resonance spectra were acquired in the medial region of the thalamus. In diffusion tensor examination, mean diffusivity and fractional anisotropy were determined at the level of medial thalamus using regions of interest delineated to outline the same parenchyma studied by spectroscopy. Voxel-based morphometry was performed focusing the analysis on the thalamus. Thalamic volumes were obtained using FMRIB's Integrated Registration and Segmentation Tool software, and shape analysis was performed using the FMRIB Software Library tools. Proton magnetic resonance spectroscopy study disclosed a significantly reduced N-acetylaspartate:creatine ratio and N-acetylaspartate concentrations in the medial thalamus of patients with restless legs syndrome compared with healthy controls (P < 0.01 for both variable). Lower N-acetylaspartate concentrations were significantly associated with a family history of restless legs syndrome (ß = -0.49; P = 0.018). On the contrary, diffusion tensor imaging, voxel-based morphometry and volumetric and shape analysis of the thalami did not show differences between the two groups. Proton magnetic resonance spectroscopic findings in patients with restless legs syndrome indicate an involvement of medial thalamic nuclei of a functional nature; however, the other structural techniques of the same region did not show any changes. These findings support the hypothesis that dysfunction of the limbic system plays a role in the pathophysiology of idiopathic restless legs syndrome.

Group I nonreciprocal inhibition in restless legs syndrome secondary to chronic renal failure.

BACKGROUND: Neurophysiological investigations disclosed spinal cord hyperexcitability in primary restless legs syndrome (p-RLS). Uremic RLS (u-RLS) is the most common secondary form, but its pathophysiological mechanisms remain unsettled. Aim of this study was to explore spinal cord excitability by evaluating group I nonreciprocal (Ib) inhibition in u-RLS patients in comparison with p-RLS patients and healthy subjects. METHODS: Eleven u-RLS patients undergoing long-term hemodialysis treatment, nine p-RLS patients and ten healthy subjects were studied. Soleus H reflex latency (HR-L), H(max)/M(max) ratio, and Ib inhibition were evaluated. Ib inhibition was tested measuring the amplitude changes in soleus H reflex following stimulation of the synergist gastrocnemius medialis (GM) nerve at rest. Nerve conduction studies were performed in the uremic patients. RESULTS: The H(max)/M(max) ratio did not differ in the three groups. The u-RLS patients showed a normal Ib inhibition comparable with the healthy group, whereas the p-RLS group had evidence of a reduced active inhibition compared with both u-RLS patients (P = 0.04) and controls (P = 0.007), prominently at 5 ms (P = 0.007) and at 6 ms (P = 0.02) of conditioning-test interval. Neurophysiological examination disclosed abnormalities ranging from higher HR-L to clear-cut polyneuropathy in most u-RLS patients. CONCLUSIONS: Unlike p-RLS patients, u-RLS patients had normal Ib inhibition, suggesting a regular supraspinal control of Ib spinal interneurons. Subclinical peripheral nerve abnormalities were detected in most uremic patients. Peripherally disrupted sensory modulation may represent the major pathophysiological determinant of uremic RLS.

Morvan chorea and agrypnia excitata: when video-polysomnographic recording guides the diagnosis.

INTRODUCTION: Morvan chorea is an antibody-mediated limbic encephalopathy characterized by severe insomnia, mental confusion, hallucinations, enacted dreams, hyperhidrosis, and neuromyotonia. CASE DESCRIPTION: In a 78 years old man presenting with progressive insomnia apathy and depression, a video-polysomnogram documented enacted dreams mimicking daily life activity (oneiric stupor). This finding led us to perform a search for serum antibodies to voltage-gated K+ channels, which was positive. A diagnosis of Morvan chorea was done. The patient underwent plasma exchange with complete resolution of the clinical picture. CONCLUSIONS: Oneiric stupor may represent a useful precocious diagnostic marker in Morvan chorea.

Rud syndrome with focal cortical dysplasia: a case report.

We report a female patient with ichthyosis, epilepsy, mental retardation, hypergonadotrophic hypogonadism, polyneuropathy, and cranial dysmorphisms. This clinical picture may satisfy the main diagnostic criteria that characterize Rud syndrome (RS), a rare neurocutaneous disease. The patient underwent extensive clinical evaluation, neurophysiological studies (wakefulness and sleep EEG, EMG), dermatological and endocrinological evaluation and neuroimaging study (3 Tesla brain MRI). Interestingly, brain MRI unveiled a malformation of cortical development, never reported previously in RS. Although seizure semiology and EEG features could not provide clear cut information suggesting a focal onset, the role of this MRI finding in the genesis of the epileptic seizures cannot be ruled out. The finding of a focal cortical dysplasia in RS might be related to genetic abnormalities affecting the development of both epidermis and neural structures with the same embryological origin.