Semantic Memory and Lexical Availability in Parkinson's Disease: A Statistical Learning Study.

Parkinson's disease (PD) is a neurodegenerative disorder that causes a progressive impairment in motor and cognitive functions. Although semantic fluency deficits have been described in PD, more specific semantic memory (SM) and lexical availability (LA) domains have not been previously addressed. Here, we aimed to characterize the cognitive performance of PD patients in a set of SM and LA measures and determine the smallest set of neuropsychological (lexical, semantic, or executive) variables that most accurately classify groups. Thirty early-stage non-demented PD patients (age 35-75, 10 females) and thirty healthy controls (age 36-76, 12 females) were assessed via general cognitive, SM [three subtests of the CaGi battery including living (i.e., elephant) and non-living things (i.e., fork)], and LA (eliciting words from 10 semantic categories related to everyday life) measures. Results showed that PD patients performed lower than controls in two SM global scores (picture naming and naming in response to an oral description). This impairment was particularly pronounced in the non-living things subscale. Also, the number of words in the LA measure was inferior in PD patients than controls, in both larger and smaller semantic fields, showing a more inadequate recall strategy. Notably, the classification algorithms indicated that the SM task had high classification accuracy. In particular, the denomination of non-living things had a classification accuracy of ∼80%. These results suggest that frontostriatal deterioration in PD leads to search strategy deficits in SF and the potential disruption in semantic categorization. These findings are consistent with the embodied view of cognition.

Deep-brain stimulation in treatment-resistant obsessive-compulsive disorder: Clinical and molecular neuroimaging correlation / Estimulación cerebral profunda en el trastorno obsesivo compulsivo resistente a tratamiento: correlato clínico y de neuroimagen molecular

ABSTRACT Introduction: Obsessive-compulsive disorder is defined by the presence of obsessions and compulsions that cause marked anxiety or distress and has been associated with a disruption in corticostriato-thalamo-cortical circuitry. After treatment, around 50% of patients continue to experience incapacitating symptoms. Deep-brain stimulation has been shown to be an effective therapeutic alternative to regular treatment. Methods: Case report. Case presentation: A 54-year-old woman with a diagnosis of treatment-resistant obsessive-compulsive disorder was treated with deep-brain stimulation of the anterior limb of the internal capsule. Molecular imaging before and after the procedure was obtained and correlated with clinical features. Conclusions: Deep-brain stimulation may be a therapeutic alternative to regular care in treatment-resistant obsessive-compulsive disorder and can be correlated to functional changes in suspected anatomical structures.

RESUMEN Introducción: El trastorno obsesivo-compulsivo se define por la presencia de obsesiones y compulsiones que ocasionan ansiedad y malestar marcados, y se ha asociado con una alteración en los circuitos cortico-estriado-tálamo-corticales. Tras tratamiento, alrededor de la mitad de los pacientes permanecen con síntomas discapacitantes. La estimulación cerebral profunda ha mostrado ser una alternativa efectiva al tratamiento usual. Métodos: Reporte de caso. Presentación del caso: Una mujer de 54 años con diagnóstico de trastorno obsesivo-compulsivo resistente a tratamiento fue tratada con estimulación cerebral profunda del brazo anterior de la cápsula interna. Se obtuvieron imágenes moleculares antes y después de la intervención y fueron correlacionadas con el cuadro clínico. Conclusiones: La estimulación magnética profunda puede ser una alternativa terapéutica al tratamiento usual en el trastorno obsesivo compulsivo resistente a tratamiento, y puede correlacionarse con cambios funcionales en estructuras anatómicas de sospecha.

Deep-brain stimulation in treatment-resistant obsessive-compulsive disorder: Clinical and molecular neuroimaging correlation.

INTRODUCTION: Obsessive-compulsive disorder is defined by the presence of obsessions and compulsions that cause marked anxiety or distress and has been associated with a disruption in cortico-striato-thalamo-cortical circuitry. After treatment, around 50% of patients continue to experience incapacitating symptoms. Deep-brain stimulation has been shown to be an effective therapeutic alternative to regular treatment. METHODS: Case report. CASE PRESENTATION: A 54-year-old woman with a diagnosis of treatment-resistant obsessive-compulsive disorder was treated with deep-brain stimulation of the anterior limb of the internal capsule. Molecular imaging before and after the procedure was obtained and correlated with clinical features. CONCLUSIONS: Deep-brain stimulation may be a therapeutic alternative to regular care in treatment-resistant obsessive-compulsive disorder and can be correlated to functional changes in suspected anatomical structures.

Valproate-induced Hyperammonemic Encephalopathy Presenting as Catatonia.

Hyperammonemic encephalopathy secondary to the use of valproate is rare without evidence of hepatotoxicity, and it usually presents with confusion, agitation, irritability, cognitive disturbances, lethargy, coma, and death. We present the case of a 21-year-old woman presenting with catatonia as a manifestation of hyperammonemic encephalopathy that resolved with the normalization of ammonia and suspension of valproate.