Clinical characteristics and treatment of perianal fistulising Crohn's disease in Colombia: Results of a multicentric registry. / Características clínicas y tratamiento de la enfermedad de Crohn perianal fistulizante en Colombia: resultados de un registro multicéntrico.

INTRODUCTION: Perianal fistulizing Crohn's disease (CD) is a phenotype with a poor prognosis. There are no studies in our country. Our objective is to determine the clinical, sociodemographic and treatment characteristics of perianal fistulizing CD in a Colombian multicenter registry. MATERIALS AND METHODS: A retrospective, multicenter observational study was carried out, with prospective data collection, in the main reference centers for inflammatory Bowel disease (IBD) in the country. Continuous variables were expressed as medians and interquartile ranges. The categorical outcome variables were compared by the Chi-square test. RESULTS: Sixty-five patients with perianal fistulizing CD were documented, with a median age of appearance of perianal fistula of 31.0 years (range: 24-42), predominantly in men (61.5%; H:M ratio: 1.4:1). Complex perianal fistulas were more frequent than simple ones (75.35 vs. 24.6%). Regarding medical treatment, 66.2% of the patients received antibiotics, 64.6% steroids, 78.5% biological therapy, 47.7% non-cutting setons, and 46.2% required surgical management, other than seton placement. Only 29.2% achieved complete remission of the fistula, and 9.2% of the patients ended up in a definitive colostomy. CD patients with complex fistulas received more biological therapy, compared to CD patients with simple fistulas (84.8 vs. 56.3%; P: 0.038). CONCLUSIONS: Perianal fistulizing CD has a poor prognosis in our setting, only 3 out of 10 patients achieve complete remission despite treatment. A multidisciplinary management is essential for the comprehensive management of this difficult pathology.

Promise and challenges of dystonia brain banking: establishing a human tissue repository for studies of X-Linked Dystonia-Parkinsonism.

X-Linked Dystonia-Parkinsonism (XDP) is a neurodegenerative disease affecting individuals with ancestry to the island of Panay in the Philippines. In recent years there has been considerable progress at elucidating the genetic basis of XDP and candidate disease mechanisms in patient-derived cellular models, but the neural substrates that give rise to XDP in vivo are still poorly understood. Previous studies of limited XDP postmortem brain samples have reported a selective dropout of medium spiny neurons within the striatum, although neuroimaging of XDP patients has detected additional abnormalities in multiple brain regions beyond the basal ganglia. Given the need to fully define the CNS structures that are affected in this disease, we created a brain bank in Panay to serve as a tissue resource for detailed studies of XDP-related neuropathology. Here we describe this platform, from donor recruitment and consent to tissue collection, processing, and storage, that was assembled within a predominantly rural region of the Philippines with limited access to medical and laboratory facilities. Thirty-six brains from XDP individuals have been collected over an initial 4 years period. Tissue quality was assessed based on histologic staining of cortex, RNA integrity scores, detection of neuronal transcripts in situ by fluorescent hybridization chain reaction, and western blotting of neuronal and glial proteins. The results indicate that this pipeline preserves tissue integrity to an extent compatible with a range of morphologic, molecular, and biochemical analyses. Thus the algorithms that we developed for working in rural communities may serve as a guide for establishing similar brain banks for other rare diseases in indigenous populations.

Neuroinflammation and histone H3 citrullination are increased in X-linked Dystonia Parkinsonism post-mortem prefrontal cortex.

Neuroinflammation plays a pathogenic role in neurodegenerative diseases and recent findings suggest that it may also be involved in X-linked Dystonia-Parkinsonism (XDP) pathogenesis. Previously, fibroblasts and neuronal stem cells derived from XDP patients demonstrated hypersensitivity to TNF-α, dysregulation in NFκB signaling, and an increase in several pro-inflammatory markers. However, the role of inflammatory processes in XDP patient brain remains unknown. Here we demonstrate that there is a significant increase in astrogliosis and microgliosis in human post-mortem XDP prefrontal cortex (PFC) compared to control. Furthermore, there is a significant increase in histone H3 citrullination (H3R2R8R17cit3) with a concomitant increase in peptidylarginine deaminase 2 (PAD2) and 4 (PAD4), the enzymes catalyzing citrullination, in XDP post-mortem PFC. While there is a significant increase in myeloperoxidase (MPO) levels in XDP PFC, neutrophil elastase (NE) levels are not altered, suggesting that MPO may be released by activated microglia or reactive astrocytes in the brain. Similarly, there was an increase in H3R2R8R17cit3, PAD2 and PAD4 levels in XDP-derived fibroblasts. Importantly, treatment of fibroblasts with Cl-amidine, a pan inhibitor of PAD enzymes, reduced histone H3 citrullination and pro-inflammatory chemokine expression, without affecting cell survival. Taken together, our results demonstrate that inflammation is increased in XDP post-mortem brain and fibroblasts and unveil a new epigenetic potential therapeutic target.

Defects in the striatal neuropeptide Y system in X-linked dystonia-parkinsonism.

Neuropeptide Y is a novel bioactive substance that plays a role in the modulation of neurogenesis and neurotransmitter release, and thereby exerts a protective influence against neurodegeneration. Using a sensitive immunohistochemical method with a tyramide signal amplification protocol, we performed a post-mortem analysis to determine the striatal localization profile of neuropeptide Y in neurologically normal individuals and in patients with X-linked dystonia-parkinsonism, a major representative of the neurodegenerative diseases that primarily involve the striatum. All of the patients examined were genetically verified as having X-linked dystonia-parkinsonism. In normal individuals, we found a scattered distribution of neuropeptide Y-positive neurons and numerous nerve fibres labelled for neuropeptide Y in the striatum. Of particular interest was a differential localization of neuropeptide Y immunoreactivity in the striatal compartments, with a heightened density of neuropeptide Y labelling in the matrix compartment relative to the striosomes. In patients with X-linked dystonia-parkinsonism, we found a significant decrease in the number of neuropeptide Y-positive cells accompanied by a marked loss of their nerve fibres in the caudate nucleus and putamen. The patients with X-linked dystonia-parkinsonism also showed a lack of neuropeptide Y labelling in the subventricular zone, where a marked loss of progenitor cells that express proliferating cell nuclear antigen was found. Our results indicate a neostriatal defect of the neuropeptide Y system in patients with X-linked dystonia-parkinsonism, suggesting its possible implication in the mechanism by which a progressive loss of striatal neurons occurs in X-linked dystonia-parkinsonism.

Immediate Impact on Tear Osmolarity Following the Application of Different Ocular Lubricants in Patients Experiencing Moderate Dry Eye Symptoms.

PURPOSE: This study addresses the growing concern of Dry Eye Disease (DED), which has become increasingly prevalent due to modern lifestyles characterized by prolonged screen usage, global warming, polypharmacy, and extended life expectancy. METHODS: Grounded in the Dry Eye Workshop II (DEWSII) diagnosis framework, the study focuses on DED as a multifactorial condition affecting the ocular surface's tear film homeostasis. The study evaluates the short-term impact of 5 commercially available ocular lubricants on disrupting the hyperosmolar environment and determine whether these lubricants can offer potential treatment benefits for DED. RESULTS: Conducted on 300 eyes (from 150 patients) with 5 preservative-free lubricants compared to a control group, the study reveals that all lubricants effectively reduced tear film osmolarity within 15 minutes of application. Notably, the control group exhibited an increase in average osmolarity (+0.98 mOsm/L) without lubricant use. Siccafluid demonstrated the most substantial osmolarity reduction after 15 minutes, with an average decrease of 11.54 mOsm/L. Statistical significance was observed for Siccafluid, Optive Fusion unique dose (UD), and Systane Ultra UD, while Hyabak and Freegen preservative free (PF) showed lower significance. CONCLUSIONS: Emphasizing the importance of disrupting the hyperosmolar environment to break the cycle of inflammation, the study concludes that ocular lubricants, at least as an immediate post-application effect, can interrupt this cycle and improve the hyperosmolar environment of the ocular surface.

Factors associated with intention to be vaccinated with the COVID-19 booster dose: a cross-sectional study in Peru.

Introduction: The pandemic of COVID-19 continues to impact people worldwide, with more than 755 million confirmed cases and more than 6.8 million reported deaths. Although two types of treatment, antiviral and immunomodulatory therapy, have been approved to date, vaccination has been the best method to control the spread of the disease. Objective: To explore factors associated with the intention to be vaccinated with the COVID-19 booster dose in Peru. Material and Methods: Cross-sectional study, using virtual and physical surveys of adults with two or more doses of COVID-19 vaccine, where the dependent variable was the intention to be vaccinated (IBV) with the booster dose. We calculated prevalence ratios with 95% confidence intervals, using generalized linear models of the Poisson family with robust varying, determining associations between sociodemographic, clinical, and booster dose perception variables. Results: Data from 924 adults were analyzed. The IBV of the booster doses was 88.1%. A higher prevalence was associated with being male (aPR = 1.05; 95% CI [1.01-1.10]), having a good perception of efficacy and protective effect (PR = 3.69; 95% CI [2.57-5.30]) and belonging to the health sector (PR = 1.10; 95% CI [1.04-1.16]). There was greater acceptance of the recommendation of physicians and other health professionals (aPR = 1.40; 95% CI [1.27-1.55]). Conclusions: Factors associated with higher IBV with booster dose include male gender, health sciences, physician recommendation, and good perception of efficacy.

Tissue-specific and repeat length-dependent somatic instability of the X-linked dystonia parkinsonism-associated CCCTCT repeat.

X-linked dystonia-parkinsonism (XDP) is a progressive adult-onset neurodegenerative disorder caused by insertion of a SINE-VNTR-Alu (SVA) retrotransposon in the TAF1 gene. The SVA retrotransposon contains a CCCTCT hexameric repeat tract of variable length, whose length is inversely correlated with age at onset. This places XDP in a broader class of repeat expansion diseases, characterized by the instability of their causative repeat mutations. Here, we observe similar inverse correlations between CCCTCT repeat length with age at onset and age at death and no obvious correlation with disease duration. To gain insight into repeat instability in XDP we performed comprehensive quantitative analyses of somatic instability of the XDP CCCTCT repeat in blood and in seventeen brain regions from affected males. Our findings reveal repeat length-dependent and expansion-based instability of the XDP CCCTCT repeat, with greater levels of expansion in brain than in blood. The brain exhibits regional-specific patterns of instability that are broadly similar across individuals, with cerebellum exhibiting low instability and cortical regions exhibiting relatively high instability. The spectrum of somatic instability in the brain includes a high proportion of moderate repeat length changes of up to 5 repeats, as well as expansions of ~ 20- > 100 repeats and contractions of ~ 20-40 repeats at lower frequencies. Comparison with HTT CAG repeat instability in postmortem Huntington's disease brains reveals similar brain region-specific profiles, indicating common trans-acting factors that contribute to the instability of both repeats. Analyses in XDP brains of expansion of a different SVA-associated CCCTCT located in the LIPG gene, and not known to be disease-associated, reveals repeat length-dependent expansion at overall lower levels relative to the XDP CCCTCT repeat, suggesting that expansion propensity may be modified by local chromatin structure. Together, the data support a role for repeat length-dependent somatic expansion in the process(es) driving the onset of XDP and prompt further investigation into repeat dynamics and the relationship to disease.

Understanding XDP through imaging, pathology, and genetics.

The X-linked dystonia-parkinsonism (XDP) is a severe, progressive, adult-onset, X-linked endemic disorder in Filipinos, which is characterized by dystonic movements that start in the third or fourth decade, and replaced by parkinsonism beyond the 10th year of illness. Understanding the pathophysiology of XDP and development of rational therapies will depend on observations from imaging, pathological, and genetic studies. In this paper we summarize the results of these studies on patients with XDP. The cranial magnetic resonance imaging shows hyperintense putaminal rim in both dystonic and parkinsonian stages, and atrophy of the caudate head or putamen in the parkinsonian stage. Neuropathological findings show atrophy of the caudate nucleus and putamen, with mild to severe neuronal loss and gliosis. In the neostriatum, the dystonic phase of XDP shows the involvement of striosomes and matrix sparing, while the later, i.e., parkinsonian phase, shows matrix involvement as well. In the dystonic phase, the loss of striosomal inhibitory projections lead to disinhibition of nigral dopaminergic neurons, perhaps resulting in a hyperkinetic state; while in the parkinsonian phase, severe and critical reduction of matrix-based projection may result in extranigral parkinsonism. Genetic sequencing of the XDP critical region in Xq13.1 has revealed an SVA retrotransposon insertion in an intron of TAF1. This may reduce neuron-specific expression of the TAF1 isoform in the caudate nucleus, and subsequently interfere with the transcription of many neuronal genes, including DRD2. Findings from imaging, pathology, and genetics studies are gradually shedding light on the pathophysiology of XDP, which hopefully will lead to more rational and directed therapies.

Dissection of TAF1 neuronal splicing and implications for neurodegeneration in X-linked dystonia-parkinsonism.

X-linked dystonia-parkinsonism (XDP) is a monogenic neurodegenerative disorder of the basal ganglia, which presents as a combination of hyperkinetic movements and parkinsonian features. The underlying genetic mechanism involves the insertion of a SINE-VNTR-Alu retrotransposon within the TAF1 gene. Interestingly, alterations of TAF1 have been involved in multiple neurological diseases. In XDP, the SINE-VNTR-Alu insertion in TAF1 has been proposed to result in alternative splicing defects, including the decreased incorporation of a neuron-specific microexon annotated as 34'. This mechanism has become controversial as recent studies failed to provide support. In order to resolve this conundrum, we examined the alternative splicing patterns of TAF1 mRNAs in XDP and control brains. The impact of the disease-associated SINE-VNTR-Alu on alternative splicing of microexon 34' was further investigated in cellular assays. Subsequently, microexon 34' incorporation was explored by RT-PCR and Nanopore long-read sequencing of TAF1 mRNAs from XDP and control brains tissues. Using cell-based splicing assays, we demonstrate that presence of the disease-associated SINE-VNTR-Alu does not affect the inclusion of microexon 34'. In addition, we show that (1) microexon 34'-containing TAF1 mRNAs are detected at similar levels in XDP as in controls and that (2) the architecture of TAF1 transcripts is remarkably similar between XDP and controls brains. These results indicate that microexon 34' incorporation into TAF1 mRNA is not affected in XDP brains. Our findings shift the current paradigm of XDP by discounting alternative splicing of TAF1 microexon 34' as the molecular basis for this disease.

Radiation-induced glioblastoma of the conus medullaris from radiation treatment of cervical cancer.

Radiation-induced spinal glioblastoma is an extremely rare disease with only four previously published reports in the literature. We report the fifth case, a 69-year-old woman who previously underwent treatment with brachytherapy for cervical cancer, and thereafter presented with neurologic deficits from a conus medullaris tumour. Biopsy and histopathology confirm glioblastoma, not otherwise specified. Treatment of spinal glioblastoma consists of surgery, either biopsy or excision and chemoradiation. However, results are still unsatisfactory and prognosis remains poor.

SVA insertion in X-linked Dystonia Parkinsonism alters histone H3 acetylation associated with TAF1 gene.

X-linked Dystonia-Parkinsonism (XDP) is a neurodegenerative disease linked to an insertion of a SINE-VNTR-Alu (SVA)-type retrotransposon within an intron of TAF1. This SVA insertion induces aberrant TAF1 splicing and partial intron retention, thereby decreasing levels of the full-length transcript. Here we sought to determine if these altered transcriptional dynamics caused by the SVA are also accompanied by local changes in histone acetylation, given that these modifications influence gene expression. Because TAF1 protein may itself exhibit histone acetyltransferase activity, we also examined whether decreased TAF1 expression in XDP cell lines and post-mortem brain affects global levels of acetylated histone H3 (AcH3). The results demonstrate that total AcH3 are not altered in XDP post-mortem prefrontal cortex or cell lines. We also did not detect local differences in AcH3 associated with TAF1 exons or intronic sites flanking the SVA insertion. There was, however, a decrease in AcH3 association with the exon immediately proximal to the intronic SVA, and this decrease was normalized by CRISPR/Cas-excision of the SVA. Collectively, these data suggest that the SVA insertion alters histone status in this region, which may contribute to the dysregulation of TAF1 expression.

Caracterización de pacientes con enfermedad de ojo seco en una institución de referencia en la ciudad de Medellín, Colombia / Characterization of patients with dry eye disease from distinguished ophthalmology clinic in Medellín, Colombia

Introducción: La enfermedad de ojo seco ha sido definida como una entidad multifactorial en la cual se pierde la homeostasis de la película lagrimal. Objetivo: Caracterizar a los pacientes con enfermedad de ojo seco atendidos en la unidad de ojo seco de la Clínica de Oftalmología Sandiego. Materiales y métodos: Estudio observacional, descriptivo, de cohorte retrospectiva. Se documentaron pruebas cualitativas, cuantitativas, cuestionario OSDI y tipo de ojo seco de los pacientes que consultaron en el periodo de marzo de 2016 a diciembre de 2017 con diagnóstico confirmado de enfermedad de ojo seco. Resultados: En 107 pacientes se confirmó el diagnóstico de ojo seco, 80.4% fueron mujeres. La mediana de edad fue 53 años (38-69). El 64.5% tenía ojo seco evaporativo, 12.2% acuodeficiente y 23.4% mixto. El OSDI fue mayor a 33 en 67 pacientes. La osmolaridad lagrimal y la MMP-9 estuvieron alteradas en 78.5 y 76.6%, respectivamente. Conclusión: La realización de pruebas clínicas, laboratorio y cuestionarios de síntomas, permiten realizar el diagnóstico integral de la enfermedad ojo seco según las recomendaciones del DEWS II, apoyando la clasificación del mismo, reconocimiento de factores de riesgo y planteamiento de posibles etiologías que ayudan en el tratamiento.

ackground: Dry eye disease has been defined by DEWS II as a multifactorial entity in which tear film homeostasis is altered. Objective: To characterize patients with dry eye disease evaluated in the dry eye unit of Clínica de Oftalmología Sandiego. Materials and methods: Observational, descriptive, retrospective cohort study. Information was collected from patients who consulted the dry eye unit in the period from March 2016 to December 2017 and who were diagnosed with dry eye disease. The results of qualitative and quantitative tests, as well as the dry eye symptoms questionnaire, were documented.

The natural history of sex-linked recessive dystonia parkinsonism of Panay, Philippines (XDP).

Sex-linked dystonia parkinsonism (XDP) was reported by Lee et al. in 1975 occurring endemically in Panay, Philippines. It is an adult onset, sex-linked, predominantly male, severe, progressive movement disorder with high penetrance and a high frequency of generalization. The movement disorder is characterized by dystonic movements usually starting in the third or fourth decade, focal at the onset, spreading to generalization within 2-5 years. The dystonia co-exist or is replaced by parkinsonism usually beyond the 10th year of illness. As of June 2001, 376 XDP cases have been registered. One hundred and fifteen cases have died. The prevalence of XDP in the island of Panay is 5.24 per 100,000; 0.34/100,000 in the general population. The prevalence varies in the different provinces; it is highest in Capiz at 18.88/100,000, 7.46/100,000 in Aklan, 1.28 in Iloilo and 0.83 in Antique. The 376 cases are from 188 families and 92% of cases have positive family history. Ninety-nine percent of the cases are males. The mean age of onset is 39.48 years. Duration of illness is 12.95 years. Ninety-four percent of patients initially manifest with dystonic symptoms, while only 6% present with Parkinsonian traits. Among those presenting with dystonia, the initial presentation is in the lower extremities in 33%, craniofacial in 27%, cervical and shoulder in 25%, upper extremities in 14%, and trunk in 1%. Regardless of the site of onset, the dystonia spreads in 98% and generalizes within 5 years in 84%. Neuroimaging (magnetic resonance imaging, MRI) was done in 16 patients. In the patients who have just manifested the disease usually when dystonia predominates and parkinsonism is absent. MRI showed minimal atrophy of the caudate and putamen or subtle putaminal signal abnormality. In the late course, where Parkinsonism predominates, severe atrophy of the caudate and putamen as well as marked increase in signal abnormality are seen. There are six autopsied cases of XDP. Neuropathology revealed marked atrophy of the caudate and putamen mostly in the cases with longstanding illness. The sex-linked pattern of inheritance has been established. Genetic studies have located the affected gene (DYT3) to Xq13.1. Nemeth's group has mapped the XDP gene to a <350 kb locus in the DXS 7117-DX 559 region. To date, no treatment has been proven consistently effective.

Características clínicas y tratamiento de la enfermedad de Crohn perianal fistulizante en Colombia: resultados de un registro multicéntrico / Clinical characteristics and treatment of perianal fistulising Crohn's disease in Colombia: Results of a multicentric registry

Introducción: La enfermedad de Crohn (EC) perianal fistulizante es un fenotipo de mal pronóstico. No existen estudios en nuestro medio. Nuestro objetivo es determinar las características clínicas, sociodemográficas y el tratamiento de la EC perianal fistulizante en un registro multicéntrico colombiano. Materiales y métodos: Se realizó un estudio observacional multicéntrico, retrospectivo, con recolección prospectiva de la información, en los principales centros de referencia de enfermedad inflamatoria intestinal (EII) del país. Las variables continuas se expresaron como medianas y rangos intercuartílicos. Las variables de resultado categóricas fueron comparados por la prueba de Chi-cuadrado. Resultados: Se documentaron 65 pacientes con EC perianal fistulizante, con una mediana de edad de aparición de fistula perianal de 31,0 años (rango: 24-42), predominando en hombres (61,5%; razón H:M: 1,4:1). Las fístulas perianales complejas fueron más frecuentes que las simples (75,35 vs. 24,6%). En cuanto al tratamiento médico, el 66,2% de los pacientes recibieron antibióticos, el 64,6% esteroides, el 78,5% terapia biológica, el 47,7% setones no cortantes y el 46,2% requirieron manejo quirúrgico, diferente a la colocación de setones. En solo el 29,2% se logró remisión completa de la fístula, y el 9,2% de los pacientes terminaron en colostomía definitiva. Los pacientes con EC con fístulas complejas recibieron más terapia biológica comparado con pacientes con EC y fístulas simples (84,8 vs. 56,3%; p: 0,038). Conclusiones: La EC perianal fistulizante es de mal pronóstico en nuestro medio, solo 3 de cada 10 pacientes logran la remisión completa a pesar del tratamiento. Un manejo multidisciplinario es fundamental para el manejo integral de esta difícil enfermedad.(AU)

Introduction: Perianal fistulizing Crohn's disease (CD) is a phenotype with a poor prognosis. There are no studies in our country. Our objective is to determine the clinical, sociodemographic and treatment characteristics of perianal fistulizing CD in a Colombian multicenter registry. Materials and methods: A retrospective, multicenter observational study was carried out, with prospective data collection, in the main reference centers for inflammatory Bowel disease (IBD) in the country. Continuous variables were expressed as medians and interquartile ranges. The categorical outcome variables were compared by the Chi-square test. Results: Sixty-five patients with perianal fistulizing CD were documented, with a median age of appearance of perianal fistula of 31.0 years (range: 24-42), predominantly in men (61.5%; H:M ratio: 1.4:1). Complex perianal fistulas were more frequent than simple ones (75.35 vs. 24.6%). Regarding medical treatment, 66.2% of the patients received antibiotics, 64.6% steroids, 78.5% biological therapy, 47.7% non-cutting setons, and 46.2% required surgical management, other than seton placement. Only 29.2% achieved complete remission of the fistula, and 9.2% of the patients ended up in a definitive colostomy. CD patients with complex fistulas received more biological therapy, compared to CD patients with simple fistulas (84.8 vs. 56.3%; P: 0.038). Conclusions: Perianal fistulizing CD has a poor prognosis in our setting, only 3 out of 10 patients achieve complete remission despite treatment. A multidisciplinary management is essential for the comprehensive management of this difficult pathology.(AU)

Understanding XDP through imaging,pathology,and genetics

The X-linked dystonia-parkinsonism (XDP) is a severe progressive, adult-onset X-linked endemic disorder in Filipinos, which is characterized by dystonic movements that start in the third of fourth decade, and replaced by parkinsonism beyond the 10th year of illness. Understanding the pathophysiology of XDP and development of rational therapies will depend on observations from imaging pathological and genetic studies. In this paper we summarize the results of these studies on patients with XDP. The cranial magnetic resonance imaging shows hy-perintense putaminal rim in both dystonic and parkinsonian stages, and atrophy of the caudate head or putamen in the parkinsonian stage. Neuropathological findings show atrophy of the caudate nucleus and putamen, with mild to severe neuronal loss and gliosis. In the neostriatum, the dystonic phase of XDP shows the involvement of striosomes and matrix sparing, while the later, i.e., p[arkinsonian phase, shows matrix involvement as well. In the dystonic phase, the loss of striosomal inhibitory projections lead to disinhibition of nigral dopaminergic neurons, perhaps resulting in a hyperkinetic state; while in the parkinsonian phase, severe and critical reduction of matrix-based projection may result in extranigral parkinsonism. Genetic sequencing of the XDP critical region in Xq13.1 has revealed an SVA retronsposon insertion in an intron of TAF1. This may reduce neuron-specific expression of the TAF1 isoform in the caudade nucleus, and subsequently interfere with the transcription of many neuronal genes, including DRD2. Findings from imaging, pahtology, and genetics studies are gradually shedding light on the pathophysiology of XDP, which hopefully will lead to mare rational and directed therapies.

Functional anatomy of the basal ganglia in X-linked recessive dystonia-parkinsonism.

Dystonia is a neurological syndrome characterized by sustained muscle contractions that produce repetitive twisting movements or abnormal postures. X-linked recessive dystonia parkinsonism (XDP; DYT3; Lubag) is an adult-onset disorder that manifests severe and progressive dystonia with a high frequency of generalization. In search for the anatomical basis for dystonia, we performed postmortem analyses of the functional anatomy of the basal ganglia based on the striatal compartments (ie, the striosomes and the matrix compartment) in XDP. Here, we provide anatomopathological evidence that, in the XDP neostriatum, the matrix compartment is relatively spared in a unique fashion, whereas the striosomes are severely depleted. We also document that there is a differential loss of striatal neuron subclasses in XDP. In view of the three-pathway basal ganglia model, we postulate that the disproportionate involvement of neostriatal compartments and their efferent projections may underlie the manifestation of dystonia in patients with XDP. This study is the first to our knowledge to show specific basal ganglia pathology that could explain the genesis of dystonia in human heredodegenerative movement disorders, suggesting that dystonia may result from an imbalance in the activity between the striosomal and matrix-based pathways.