Heavy metals contaminating the environment of a progressive supranuclear palsy cluster induce tau accumulation and cell death in cultured neurons.

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder characterized by the presence of intracellular aggregates of tau protein and neuronal loss leading to cognitive and motor impairment. Occurrence is mostly sporadic, but rare family clusters have been described. Although the etiopathology of PSP is unknown, mutations in the MAPT/tau gene and exposure to environmental toxins can increase the risk of PSP. Here, we used cell models to investigate the potential neurotoxic effects of heavy metals enriched in a highly industrialized region in France with a cluster of sporadic PSP cases. We found that iPSC-derived iNeurons from a MAPT mutation carrier tend to be more sensitive to cell death induced by chromium (Cr) and nickel (Ni) exposure than an isogenic control line. We hypothesize that genetic variations may predispose to neurodegeneration induced by those heavy metals. Furthermore, using an SH-SY5Y neuroblastoma cell line, we showed that both heavy metals induce cell death by an apoptotic mechanism. Interestingly, Cr and Ni treatments increased total and phosphorylated tau levels in both cell types, implicating Cr and Ni exposure in tau pathology. Overall, this study suggests that chromium and nickel could contribute to the pathophysiology of tauopathies such as PSP by promoting tau accumulation and neuronal cell death.

The MAPT gene is differentially methylated in the progressive supranuclear palsy brain.

BACKGROUND: Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease causing parkinsonian symptoms. Altered DNA methylation of the microtubule-associated protein tau gene correlates with the expression changes in Alzheimer's disease and Parkinson's disease brains. However, few studies examine the sequences beyond the constitutive promoter. OBJECTIVES: Because activating different microtubule-associated protein tau gene control regions via methylation might regulate the differential tau expression constituting the specific signatures of individual tauopathies, we compared methylation of a candidate promoter, intron 0. METHODS: We assessed DNA methylation in the brains of patients with different tauopathies (35 Alzheimer's disease, 10 corticobasal degeneration, and 18 PSP) and 19 controls by intron 0 pyrosequencing. We also evaluated methylation in an independent cohort of 11 PSP cases and 12 controls. Frontal (affected by tau pathology) and occipital (unaffected) cortices were analyzed. RESULTS: In the initial samples, one CpG island site in intron 0 (CpG1) showed significant hypomethylation in PSP-affected frontal cortices when compared with controls (P = .022). Such hypomethylation was observed in replicate samples, but not in occipital cortices or other tauopathies. PSP and control samples (combining the initial and replicate samples) remained significantly different after adjustment for potential confounding factors (age, H1/H1 diplotype; P = .0005). PSP-affected tissues exhibited microtubule-associated protein tau RNA hyperexpression when compared with controls (P = .004), although no correlation with CpG1 methylation was observed. CONCLUSIONS: This exploratory study suggests that regions other than the constitutive promoter may be involved in microtubule-associated protein tau gene regulation in tauopathies and that intron 0 hypomethylation may be a specific epigenetic signature of PSP. These preliminary findings require confirmation. © 2016 International Parkinson and Movement Disorder Society.

A geographical cluster of progressive supranuclear palsy in northern France.

OBJECTIVE: To describe a cluster of progressive supranuclear palsy (PSP) in northern France. PSP has not been reported in geographical, temporal, or occupational clusters. A unit of Neurology and Neurogeriatrics opened in 2005 at the Centre Hospitalier de Wattrelos, serving the population of Wattrelos and Leers (combined population 51,551) and parts of neighboring towns. For most of the 20th century, this area was a center for chromate and phosphate ore processing, textile dyeing, and tanning. Significant industrial waste persists close to residential areas. METHODS: From 2005 to 2014, 92 patients with PSP at Centre Hospitalier de Wattrelos were identified and studied. Detailed residential data were available in the medical records. Eighty cases have had magnetic resonance head scanning and 60 have died, of whom 13 have been examined neuropathologically. RESULTS: The ratio of observed to expected PSP incidence over the period 2005 to 2012 was 12.3 (95% confidence interval: 7.4-35.9). Mean onset age was 74.3 years. The Richardson syndrome/PSP-parkinsonism ratio was 43%/42%. Four other phenotypes each occurred in 2% to 5%. Onset was gait/balance difficulty in 52%. None of the 92 affected patients were relatives and 7 were of North African ancestry. MRI was compatible with a clinical diagnostic of PSP in all cases. Histopathologic examination confirmed neurofibrillary degeneration and tufted astrocytes in all autopsied cases. Western blots revealed a typical tau 4R doublet. The tau H1 haplotype occurred in 95.8% of cases' chromosomes. CONCLUSIONS: We have identified a cluster of PSP in a geographical area with severe environmental contamination by industrial metals.

Prevalence of small cerebral bleeds in patients with progressive supranuclear palsy: a neuropathological study with 7.0-Tesla magnetic resonance imaging correlates.

INTRODUCTION: Progressive supranuclear palsy (PSP) is a degenerative disease affecting mainly the brain stem, basal ganglia and cerebellum. Associated cerebrovascular lesions, mainly small cerebral bleeds, are frequently observed in some neurodegenerative diseases such as Alzheimer dementia and rare in others such as frontotemporal lobar degeneration. The present post-mortem study investigates the prevalence and distribution of small cerebral bleeds in PSP brains. MATERIAL AND METHODS: Nineteen brains of PSP patients were compared to 12 age-matched controls. The prevalence and distribution of mini-bleeds were investigated on a coronal section of a cerebral hemisphere at the level of the mamillary bodies and on a horizontal section through the pons and cerebellum. In addition, out of these series T2*-weighted gradient-echo 7.0-Tesla magnetic resonance imaging (MRI) of 3 coronal sections of a cerebral hemisphere and of a brain stem and cerebellum was performed in 14 PSP and 11 control brains. RESULTS: Although the total number of mini-bleeds was the same on neuropathological examination of both groups, they prevailed around the dentate nucleus of the cerebellum (p = 0.05) and in the tegmentum pontis (p = 0.05) of the PSP brains. On MRI the small bleeds were also more frequent around the dentate nucleus of the cerebellum (p = 0.02) and in the pons (p = 0.04) of PSP brains. DISCUSSION: In PSP brains, mini-bleeds only prevail in the regions affected by the neurodegenerative process, similarly to what happens in frontotemporal lobar degeneration. They should be considered as the result of increased angiogenesis and microglial activation, leading to associated disturbances of the blood-brain barrier in the most affected regions of PSP. They are not indicative of cerebrovascular disease.

Geographic isolates of atypical Parkinsonism and tauopathy in the tropics: possible synergy of neurotoxins.

Over the last 60 years an abnormally high prevalence of atypical Parkinsonism has been reported in 5 different geographic isolates. It was first described on Guam, later in New Guinea and in the Kii peninsula, on Guadeloupe, and in New Caledonia. We investigated the phenotype of atypical Parkinsonism in three of these foci and observed several similarities with dementia in most and amyotrophic lateral sclerosis in some. This disappearance of this disease in two places--Guam and New Guinea--suggested an environmental origin which has not been clarified before the disease ended. The exposure to annonaceae acetogenins and/or rotenone has been documented in four of these places, and experimental studies in animals demonstrated annonaceae acetogenins neurotoxicity, which is similar to rotenone neurotoxicity. Simultaneous exposure to acetogenins and rotenone could produce a synergistic toxicity on neurons.

Atypical unclassifiable parkinsonism on Guadeloupe: an environmental toxic hypothesis.

We characterize the clinical features of Parkinson's syndrome on Guadeloupe and describe possible environmental causes. Consecutive patients who were referred to the University Hospital at Pointe a Pitre with parkinsonism from September 1996 to May 2002 were included. All cases were examined in a standardized manner by a neurologist with a special interest in movement disorders and independently by 3 external movement disorders specialists, using standard operational clinical diagnostic criteria. The subjects were 265 patients with Parkinson's syndrome living on Guadeloupe, four fifths of whom had been referred by primary care physicians and one fifth by neurologists. The levodopa response was assessed after a minimum period of 1 month of continuous treatment. All patients had brain computed tomography or brain magnetic resonance imaging scans and detailed neuropsychological examinations. Of 265 patients, only 66 were classified as Parkinson's disease, whereas 58 fulfilled the National Institute of Neurological Disorders and Stroke (NINDS) and Society for Progressive Supranuclear Palsy (SPSP) criteria for progressive supranuclear palsy, 100 had unclassifiable parkinsonism, characterized by dopa-unresponsiveness, marked axial rigidity, relative symmetry of parkinsonian features, early dysarthria, and frontolimbic cognitive impairment. Within this group, early postural instability, dysarthria, a frontal behavior disorder, cortical or subcortical atrophy, pyramidal signs, axial rigidity, and family history of neurodegenerative disorders were associated with poorer prognosis. A very large number of unclassifiable cases of atypical parkinsonism that do not fulfill operational criteria for Parkinson's disease or other defined motor neurodegenerations has been observed on Guadeloupe. Most patients closely resemble descriptions of bodig from Guam. In both geographic isolates, an environmental cause has been discussed. Annonaceae fruits and herbal teas are consumed on both islands. These plants contain several neurotoxins, particularly acetogenins, which induce dopaminergic neuron loss in animals. Neuronal death involves cholinergic and dopaminergic cells of the substantia nigra and GABAergic neurons of the striatum, associated with microglial proliferation. The development of atypical parkinsonism in Guadeloupe and probably elsewhere, could result from synergistic toxicity, but acetogenins are probably the most potent neurotoxin, acting as mitochondrial complex I inhibitor.

Atypical parkinsonism on Guadeloupe, comparison with the parkinsonism-dementia complex of Guam, and environmental toxic hypotheses.

INTRODUCTION: : On Guadeloupe, atypical parkinsonism is abnormally frequent, and represents 75% of progressive parkinsonism while Parkinson's disease (PD) accounts for only 25%, which is an inversed percentage in comparison with Europe. Herbal tea made with Annonaceae leaves (containing benzyltetrahydroisoquinolines (Be-TIQ), tetrahydroprotoberberines (THPB) and acetogenins (potent mitochondrial complex I inhibitors) are commonly used on Guadeloupe. CLINICAL STUDY: : Of 265 patients studied on Guadeloupe, 66 (25%) had PD, and 199 (75%) had atypical parkinsonism. This latter group includes 58 patients (29%) with progressive supranuclear palsy (PSP), and 100 patients (50%) with unclassifiable parkinsonism (UP). This focus resembles the parkinsonism-dementia complex (PDC) described on Guam, where a very high prevalence of atypical parkinsonism has been reported since the second World War, including one-third of PSP. A preliminary case-control study on Guadeloupe showed a significant higher consumption of fruits and herbal tea of Annonaceae in atypical parkinsonian cases (PSP and unclassifiable parkinsonism, UP), compared to hospital controls and to idiopathic PD. DISCUSSION: : The overrepresentation of atypical parkinsonism on Guadeloupe and Guam could be related to the consumption of plants containing (simultaneously) isoquinoline derivates which are toxic for dopaminergic neurons and inhibitors of the mitochondrial respiratory chain such as acetogenins. This hypothesis is in keeping with epidemiologic data and experimental studies showing neuronal loss after exposure to isoquinolines or acetogenins.

Detection and determination of reticuline and N-methylcoculaurine in the Annonaceae family using liquid chromatography-tandem mass spectrometry.

In Guadeloupe, the French West Indies, there is a high incidence of atypical parkinsonism or progressive supranuclear palsy, and all of the investigated patients had taken herbal tea or tropical fruits of the Annonaceae family. Local inhabitants consume the fruits, and also drink tea made from the leaves. In the present study, we used liquid chromatography-tandem mass spectrometry (LC/MS/MS) with multiple reaction monitoring (MRM) to detect low-molecular-weight neurotoxic benzylisoquinoline derivatives in the Annonaceae family. We detected reticuline and N-methylcoculaurine in every Annona muricata sample examined, except for pulp and seed. They were not detected in sweetsop fruits. Norreticuline was not detected in any sample. These three compounds were toxic to SH-SY5Y neuroblastoma cells and inhibited mitochondrial respiratory complex I. It is possible that uptake of the benzylisoquinoline derivatives reticuline and N-methylcoculaurine and their accumulation in the brain may be related to the pathogenesis of the local endemic disease.

[Peroneal nerve palsy induced by anterior tibialis pyomyositis]. / Pyomyosite du jambier antérieur: une cause inhabituelle de mononévrite du sciatique poplité externe.

A 16-year-old girl from Guadeloup developed paresis of the flexors of the right foot, associated with edema and acute pain located in the upper anterior tibialis muscle. Electromyography confirmed mononeuritis of the right peroneal nerve, with severe reduction of potential amplitude. Computed tomography of the right leg showed a heterogeneous mass involving the upper segment of the anterior tibialis muscle, close to the location of peroneal nerve. Muscle biopsy confirmed pyomyositis. Muscle culture was negative. Paresis improved soon after antibiotic therapy was started.

[Subacute motor neuropathy induced by T3 hyperthyroidism]. / Neuropathie motrice subaiguë révélatrice d'une hyperthyroïdie à T3.

Subacute motor neuropathy involving bulbar nerves is an unusual complication of hyperthyroidism. Clinical and neurophysiologic follow-up of such patients has been rarely reported. We describe a 41-year-old Colombian patient who developed respiratory failure associated with motor neuropathy and severe weight loss. The major clinical features included diffuse amyotrophy, bilateral facial paresis, and fasciculations, suggesting motor neuropathy. Electromyography confirmed the presence of axonal neuropathy, with predominant motor involvement. Goiter with hypervascularization was noticed, associated with pure T3 hyperthyroidism (T3l=26 pg/ml; N<3.8). The patient was given carbimazole which induced a severe skin vasculitis 10 days later. Carbimazole was stopped and replaced by propylthiouracile, which also induced vasculitis with secondary cardiac failure. Total thyroidectomy was then performed. General status improved rapidly as well as motor deficit, amyotrophy and pyramidal syndrome. Electromyographic abnormalities improved significantly within 3 months. This observation demonstrates that hyperthyroidism can produce motor axonal neuropathy, curable with radical surgery.

Progressive supranuclear palsy and its relation to pacific foci of the parkinsonism-dementia complex and Guadeloupean parkinsonism.

Steele, Richardson and Olszweski in 1964 described a distinctive clinical and pathological entity they called progressive supranuclear palsy (PSP). Now on Guadeloupe in the Carribbean French West Indies, Caparros-Lefebvre is identifying many patients with similar clinical and histological features. Others have a clinical syndrome of atypical parkinsonism that resembles the parkinsonism-dementia complex (PDC) of Guam and the Kii peninsula of Japan (PDC). But in those Pacific foci the histology is different and the abnormal tau is of Alzheimer's type rather than the PSP type of Guadeloupe. In both locales, neurotoxins of local foods are implicated in etiology. Future studies will confirm if Guadeloupean parkinsonism is truly a geographic focus of PSP, and if dietary factors account for both.

Neurological manifestations of Behçet's disease in a Caribbean population: clinical and imaging findings.

Behçet's disease (BD) is a chronic relapsing multisystem disorder. While most frequently occurring around the Mediterranean and in Japan, isolated cases of BD have been reported in Africa south of the Sahara and in the Caribbean. The aim of this study was to describe our experience of BD in Guadeloupe (French West Indies) where the presence of the disease has not been reported previously. We analysed retrospectively the charts, and clinical and imaging features of patients native to Guadeloupe who were diagnosed with neurological manifestations of BD between 1989 and 1999. In our series of 13 cases, seven had neurological involvement. Neurological manifestations included meningoencephalitis or meningoencephalomyelitis in four cases, cerebral venous thrombosis in one case and peripheral neuropathy in two cases associated with myositis in one. Patients received treatment with colchicine (n=7), corticosteroids (n=6), immunosuppressive therapy (azathioprine and/or cyclophosphamide; n=4), acetylsalicylic acid (n=2) and oral anticoagulation for venous thrombosis (n=1). Long-term sequelae occurred only in patients with recurrent neurological disease. This study suggests that the frequency of BD in this Afro-Caribbean population is higher than this reported in Caucasian populations. Meningoencephalitis is associated with a poor prognosis while other patients achieved recovery.

Guadeloupean parkinsonism: a cluster of progressive supranuclear palsy-like tauopathy.

An unusually high frequency of atypical Parkinson syndrome has been delineated over the last 5 years in the French West Indies. Postural instability with early falls, prominent frontal lobe dysfunction and pseudo-bulbar palsy were common and three-quarters of the patients were L-dopa unresponsive. One-third of all patients seen had probable progressive supranuclear palsy (PSP). This new focus of atypical parkinsonism is reminiscent of the one described in Guam and may be linked to exposure to tropical plants containing mitochondrial complex I inhibitors (quinolines, acetogenins, rotenoids). Two hundred and twenty consecutive patients with Parkinson's syndrome seen by the neurology service at Pointe à Pitre, Guadeloupe University Hospital were studied. Currently accepted operational clinical criteria for Parkinson's syndromes were applied. The pathological findings of three patients who came to autopsy are reported. Fifty-eight patients had probable PSP, 96 had undetermined parkinsonism and 50 had Parkinson's disease, 15 had amyotrophic lateral sclerosis with parkinsonism and one had probable multiple system atrophy. All three PSP patients in whom post-mortem study was performed had early postural instability, gaze palsy and parkinsonian symptoms, followed by a frontolimbic dementia and corticobulbar signs. Neuropathological examination showed an accumulation of tau proteins, predominating in the midbrain. There was an exceptionally large accumulation of neuropil threads in Case 1. Biochemical studies detected a major doublet of pathological tau at 64 and 69 kDa in brain tissue homogenates. All cases were homozygous for the H1 tau haplotype, but no mutation of the tau gene was observed. Clinical, neuropathological and biochemical features were compatible with the diagnosis of PSP, although some unusual pathological features were noted in Case 1. A cluster of cases presenting with atypical parkinsonism is reported. Guadeloupean parkinsonism may prove to be a tauopathy identical or closely related to PSP.

Toxicity of Annonaceae for dopaminergic neurons: potential role in atypical parkinsonism in Guadeloupe.

In the French West Indies there is an abnormally high frequency of levodopa-resistant parkinsonism, suggested to be caused by consumption of fruit and infusions of tropical plants, especially Annona muricata (corossol, soursop). To determine whether toxic substances from this plant can cause the neuronal degeneration or dysfunction underlying the syndrome, we exposed mesencephalic dopaminergic neurons in culture to the total extract (totum) of alkaloids from Annona muricata root bark and to two of the most abundant subfractions, coreximine and reticuline. After 24 hours, 50% of dopaminergic neurons degenerated with 18 microg/ml totum, 4.3 microg/ml (13 microM) coreximine, or 100 microg/ml (304 microM) reticuline. The effects of the alkaloid totum were not restricted to the population of dopaminergic cells since GABAergic neurons were also affected by the treatment. Nuclei in dying neurons showed DNA condensation or fragmentation, suggesting that neuronal death occurred by apoptosis. Cell death was not excitotoxic and did not require toxin uptake by the dopamine transporter. Neurodegeneration was attenuated by increasing the concentration of glucose in the culture medium, which also reduced the effect of the dopaminergic neurotoxin MPP+, a mitochondrial respiratory chain inhibitor. Toxin withdrawal after short-term exposure arrested cell death. Acute treatment with totum, coreximine, or reticuline reversibly inhibited dopamine uptake by a mechanism that was distinct from that causing neuronal death. GABA uptake was not reduced under the same conditions. This study suggests that alkaloids from A. muricata can modulate the function and the survival of dopaminergic nerve cells in vitro. It is therefore conceivable that repeated consumption could cause the neuronal dysfunction and degeneration underlying the West Indian parkinsonian syndrome.

Encephalomyelitis with rigidity complicating human immunodeficiency virus infection.

A 34-year-old man with human immunodeficiency virus type 1 (HIV-1) presented with axial rigidity, painful spasms, and delayed hemiparesis and dementia. Cerebrospinal fluid analysis showed no antiglutamic acid dehydrogenase antibodies but viral genome from Epstein-Barr virus was detected by polymerase chain reaction. Clinical features and possible viral aetiology of progressive encephalomyelitis with rigidity are briefly discussed.