Orlando Graziani Povoas Barsottini

Syndrome of Hepatic Cirrhosis, Dystonia, Polycythemia, and Hypermanganesemia Caused by Mutations in SLC30A10, a Manganese Transporter in Man

Environmental manganese (Mn) toxicity causes an extrapyramidal, parkinsonian-type movement disorder with characteristic magnetic resonance images of Mn accumulation in the basal ganglia. We have recently reported a suspected autosomal recessively inherited syndrome of hepatic cirrhosis, dystonia, polycythemia, and hypermanganesemia in cases without environmental Mn exposure. Whole-genome mapping of two consanguineous families identified SLC30A10 as the affected gene in this inherited type of hypermanganesemia. This gene was subsequently sequenced in eight families, and homozygous sequence changes were identified in all affected individuals. The function of the wild-type protein and the effect of sequence changes were studied in the manganese-sensitive yeast strain Δpmr1. Expressing human wild-type SLC30A10 in the Δpmr1 yeast strain rescued growth in high Mn conditions, confirming its role in Mn transport. The presence of missense (c.266T>C [p.Leu89Pro]) and nonsense (c.585del [p.Thr196Profs(∗)17]) mutations in SLC30A10 failed to restore Mn resistance. Previously, SLC30A10 had been presumed to be a zinc transporter. However, this work has confirmed that SLC30A10 functions as a Mn transporter in humans that, when defective, causes Mn accumulation in liver and brain. This is an important step toward understanding Mn transport and its role in neurodegenerative processes.

Nonmotor and extracerebellar features in Machado-Joseph disease: a review.

Spinocerebellar ataxia type 3 or Machado‐Joseph disease is the most common spinocerebellar ataxia worldwide, and the high frequency of nonmotor manifestations in Machado‐Joseph disease demonstrates how variable is the clinical expression of this single genetic entity. Anatomical, physiological, clinical, and functional neuroimaging data reinforce the idea of a degenerative process involving extracerebellar regions of the nervous system in Machado‐Joseph disease. Brain imaging and neuropathologic studies have revealed atrophy of the pons, basal ganglia, midbrain, medulla oblongata, multiple cranial nerve nuclei, and thalamus and of the frontal, parietal, temporal, occipital, and limbic lobes. This review provides relevant information about nonmotor manifestations and extracerebellar symptoms in Machado‐Joseph disease. The main nonmotor manifestations of Machado‐Joseph disease described in previous data and discussed in this article are: sleep disorders, cognitive and affective disturbances, psychiatric symptoms, olfactory dysfunction, peripheral neuropathy, pain, cramps, fatigue, nutritional problems, and dysautonomia. In addition, we conducted a brief discussion of noncerebellar motor manifestations, highlighting movement disorders.

Cerebellar Cognitive Affective Syndrome in Machado Joseph Disease: Core Clinical Features

The cerebellum is no longer considered a purely motor control device, and convincing evidence has demonstrated its relationship to cognitive and emotional neural circuits. The aims of the present study were to establish the core cognitive features in our patient population and to determine the presence of Cerebellar Cognitive Affective Syndrome (CCAS) in this group. We recruited 38 patients with spinocerebellar ataxia type 3 (SCA3) or Machado–Joseph disease (MJD)-SCA3/MJD and 31 controls. Data on disease status were recorded (disease duration, age, age at onset, ataxia severity, and CAG repeat length). The severity of cerebellar symptoms was measured using the International Cooperative Ataxia Rating Scale and the Scale for the Assessment and Rating of Ataxia. The neuropsychological assessment consisted of the Mini-Mental State Examination, Clock Drawing Test, Wechsler Adult Intelligence Scale, Rey–Osterrieth Complex Figure, Wisconsin Card Sorting Test, Stroop Color–Word Test, Trail-Making Test, Verbal Paired Associates, and verbal fluency tests. All subjects were also submitted to the Hamilton Anxiety Scale and Beck Depression Inventory. After controlling for multiple comparisons, spatial span, picture completion, symbol search, Stroop Color–Word Test, phonemic verbal fluency, and Trail-Making Tests A and B were significantly more impaired in patients with SCA3/MJD than in controls. Executive and visuospatial functions are impaired in patients with SCA3/MJD, consistent with the symptoms reported in the CCAS. We speculate on a possible role in visual cortical processing degeneration and executive dysfunction in our patients as a model to explain their main cognitive deficit.

Brain SPECT imaging in Sydenham's chorea

The objective of the present study was to determine whether brain single-photon emission computed tomography (SPECT) imaging is capable of detecting perfusional abnormalities. Ten Sydenhams chorea (SC) patients, eight females and two males, 8 to 25 years of age (mean 13.4), with a clinical diagnosis of SC were submitted to brain SPECT imaging. We used HMPAO labeled with technetium-99m at a dose of 740 MBq. Six examinations revealed hyperperfusion of the basal ganglia, while the remaining four were normal. The six patients with abnormal results were females and their data were not correlated with severity of symptoms. Patients with abnormal brain SPECT had a more recent onset of symptoms (mean of 49 days) compared to those with normal SPECT (mean of 85 days) but this difference did not reach statistical significance. Brain SPECT can be a helpful method to determine abnormalities of the basal ganglia in SC patients but further studies on a larger number of patients are needed in order to detect the phase of the disease during which the examination is more sensitive.

Sleep disorders in cerebellar ataxias

Cerebellar ataxias comprise a wide range of etiologies leading to central nervous system-related motor and non-motor symptoms. Recently, a large body of evidence has demonstrated a high frequency of non-motor manifestations in cerebellar ataxias, specially in autosomal dominant spinocerebellar ataxias (SCA). Among these non-motor dysfunctions, sleep disorders have been recognized, although still under or even misdiagnosed. In this review, we highlight the main sleep disorders related to cerebellar ataxias focusing on REM sleep behavior disorder (RBD), restless legs syndrome (RLS), periodic limb movement in sleep (PLMS), excessive daytime sleepiness (EDS), insomnia and sleep apnea.

Genetic and environmental findings in early‐onset Parkinson's disease Brazilian patients

Parkinsons disease (PD) etiology has been attributed both to genetic and environmental factors. In this study, we investigated Brazilian early‐onset PD (EOPD) patients for mutations in PARK2 and PARK8, exposure to environmental factors and possible correlations between PARK2 polymorphisms, environmental exposure, and disease age of onset. We enrolled 72 EOPD index patients and 81 healthy volunteers. Both groups were investigated for environmental exposure. EOPD patients were screened for PARK2 and PARK8 mutations. PARK2 coding polymorphisms Ser167Asn and Val380Leu were investigated in both groups. Mutations were present in 18% of the patients and in 32% of those with a positive family history. PARK2 mutations represented 12.5% and PARK8 mutations accounted for 5.5% of the mutations. A novel PARK2 mutation (D53X) was identified in 2 patients. A positive correlation was found between EOPD and well water drinking. In patients exposed to well water, a later age of onset was observed for those who carried at least one PARK2 380Leu allele. PARK2 mutations have an important role in EOPD Brazilian patients and PARK8 might be the second most important disease causing gene in this group. Well water drinking exposure represents a risk factor for EOPD and the PARK2 coding polymorphism Val380Leu might be interacting with environmental factors acting as a disease modifier.

ALS5/SPG11/KIAA1840 mutations cause autosomal recessive axonal Charcot–Marie–Tooth disease

Mutations in the ALS5/SPG11/ KIAA1840 gene cause autosomal recessive hereditary spastic paraplegia or autosomal recessive juvenile amyotrophic lateral sclerosis. Montecchiani et al . show that KIAA1840 mutations can manifest also as recessive Charcot-Marie-Tooth disease. They describe 12 kindreds with 15 different mutations, two of which have not been reported previously.

Sleep Disorders in Machado–Joseph Disease: Frequency, Discriminative Thresholds, Predictive Values, and Correlation with Ataxia-Related Motor and Non-Motor Features

Sleep disorders are common complaints in patients with neurodegenerative diseases such as spinocerebellar ataxia type 3 (SCA3) or Machado–Joseph disease (MJD)—SCA3/MJD. We evaluated the frequency of sleep disorders in SCA3/MJD patients against controls matched by age and gender, and correlated data with demographic and clinical variables. The main sleep disorders evaluated were rapid eye movement (REM) sleep behavior disorder (RBD), restless leg syndrome (RLS), and excessive daytime sleepiness (EDS). We recruited 40 patients with clinical and molecular-proven SCA3/MJD and 38 controls. We used the following clinical scales to evaluate our primary outcome measures: RBD Screening Questionnaire, International RLS Rating Scale, and Epworth Sleepiness Scale. To evaluate ataxia-related motor and non-motor features, we applied the International Cooperative Ataxia Rating Scale, the Scale for the Assessment and Rating of Ataxia, and the Unified Parkinson’s Disease Rating Scale part III. Psychiatric manifestations were tested with the Hamilton Anxiety Scale, and Beck Depression Inventory. The frequency of RBD and RLS were significantly higher in the SCA3/MJD group than in the control group (p < 0.001). There was no difference between both groups with regard to EDS. The accuracy of RDBSQ to discriminate between cases and controls was considered the best area under the ROC curve (0.86). Within-SCA3/MJD group analysis showed that anxiety and depression were significantly correlated with RDB, but not with RLS. Additionally, depression was considered the best predictive clinical feature for RDB and EDS.

Dopaminergic Neuronal Imaging in Genetic Parkinson's Disease: Insights into Pathogenesis

Objectives To compare the dopaminergic neuronal imaging features of different subtypes of genetic Parkinsons Disease. Methods A retrospective study of genetic Parkinsons diseases cases in which DaTSCAN (123I-FP-CIT) had been performed. Specific non-displaceable binding was calculated for bilateral caudate and putamen for each case. The right:left asymmetry index and striatal asymmetry index was calculated. Results Scans were available from 37 cases of monogenetic Parkinsons disease (7 glucocerebrosidase (GBA) mutations, 8 alpha-synuclein, 3 LRRK2, 7 PINK1, 12 Parkin). The asymmetry of radioligand uptake for Parkinsons disease with GBA or LRRK2 mutations was greater than that for Parkinsons disease with alpha synuclein, PINK1 or Parkin mutations. Conclusions The asymmetry of radioligand uptake in Parkinsons disease associated with GBA or LRRK2 mutations suggests that interactions with additional genetic or environmental factors may be associated with dopaminergic neuronal loss.

Milestones in Friedreich ataxia: more than a century and still learning

Friedreich ataxia (FRDA) is the most common autosomal recessive ataxia worldwide. This review highlights the main clinical features, pathophysiological mechanisms, and therapeutic approaches for FRDA patients. The disease is characterized by a combination of neurological involvement (ataxia and neuropathy), cardiomyopathy, skeletal abnormalities, and glucose metabolism disturbances. FRDA is caused by expanded guanine-adenine-adenine (GAA) triplet repeats in the first intron of the frataxin gene (FXN), resulting in reduction of messenger RNA and protein levels of frataxin in different tissues. The molecular and metabolic disturbances, including iron accumulation, lead to pathological changes characterized by spinal cord and dorsal root ganglia atrophy, dentate nucleus atrophy without global cerebellar volume reduction, and hypertrophic cardiomyopathy. DNA analysis is the hallmark for the diagnosis of FRDA. There is no specific treatment to stop the disease progression in FRDA patients. However, a number of drugs are under investigation. Therapeutic approaches intend to improve mitochondrial functioning and to increase FXN expression.