Spatial orientation: A relationship with inferential memory.

Two branches of the scientific literature have dominated our understanding of hippocampal function. One focuses on the support this structure offers to declarative memory, while the other views the hippocampus as a part of a system dedicated to spatial navigation. These two different visions can be reconciled in relational theory, which suggests that the hippocampus processes all kinds of associations and sequences of events. According to this, processing would be similar to a route calculation based on associations of spatial information acquired during navigation and the associative relationship established between memories without spatial content. In this paper, we present a behavioral study of healthy individuals to explore the performance of inferential memory tasks and spatial orientation tasks in a virtual environment. Inferential memory and spatial orientation task performances were positively correlated. However, after controlling for a non-inferential memory task, only the correlation between allocentric spatial orientation and inferential memory remained significant. These results provide support for the similarity between the two cognitive functions, lending credence to the relational theory of the hippocampus. Additionally, our behavioral findings are in line with the cognitive map theory, which suggests a potential association between the hippocampus and allocentric spatial representations.

Cerebral venous thrombosis following an immunoglobulin-E mediated anaphylactic reaction.

BACKGROUND: Prothrombotic and pro-inflammatory states are known cerebral venous thrombosis risk factors. To date, two cases of venous thrombotic events after immunoglobulin-E mediated anaphylaxis have been reported. Herein, we describe the first case of cerebral venous thrombosis in close temporal relation with an immunoglobulin-E mediated anaphylactic event. CASE DESCRIPTION: A 51-year-old female presented with headache, language, and mental disturbance lasting for two days. Two days before the onset, she had undergone a provocative test with deflazacort to study an allergy history; after the test she developed a severe anaphylactic reaction. There were no other comorbidities, and in addition to contraceptive pill, she did not take other medications. On admission the patient was drowsy, with anomic aphasia, inattention and memory impairment. Magnetic Resonance Imaging depicted a left caudate and lenticulo-capsulo-thalamic venous infarct and thrombosis in the deep venous system. The patient was treated with anticoagulation and showed progressive improvement. Neoplastic and pro-thrombotic diseases were excluded. CONCLUSION: The close temporal association between the anaphylactic reaction and cerebral venous thrombosis suggests that anaphylactic reaction could have been a cerebral venous thrombosis precipitating factor. Immunoglobulin-E have been suggested to have prothrombotic activity by stimulating the release of platelet activation factor, thromboxane A2 and serotonin. This case adds on to the available information on possible cerebral venous thrombosis associated conditions.

Time perception changes in stroke patients: A systematic literature review.

Introduction: Time perception comprises the subjective experience of passing of time and of the duration of an event. Although already described in some neurological and psychiatric conditions, there is a paucity of details regarding this neurocognitive change in stroke patients. We aimed to describe time perception dysfunction in stroke patient. Methods: We performed a systematic review of the literature in Pubmed, PsycInfo and EMBASE including manuscripts from their inception until December 2020. We collected data regarding the type of time perception that was detected, type of stroke, most common location of lesions, evaluation tests that were used and time of evaluation after stroke onset. Results: A total of 27 manuscripts were selected, concerning a total of 418 patients (n = 253 male; 60.5%). Most manuscripts (n = 21) evaluated patients with ischaemic lesions (n = 407; 97.4%). The majority referred to evaluations between 2 months and seven years after stroke. Underestimation in temporal evaluation in sub- and supra-second was the most common dysfunction (n = 165; 41.7%). Overestimation of time (n = 116; 27.8%) and impaired time interval comparison (n = 88; 22.2%) were also found. Most patients had right hemisphere lesions (n = 219 patients; 52.4%). Common reported lesion locations included the thalamus, insula, basal ganglia, dorsolateral prefrontal cortex, parietal cortex including supramarginal, angular gyrus and right inferior parietal cortex and cerebellum. Conclusion: There are multiple stroke locations associated with time perception dysfunction, which highlights the complex system involved in time perception. There is still scarce knowledge about specific time perception deficits after stroke. Most studies rely in psychometric analysis without clear clinical and functional translation, namely regarding impact on daily activities.

Cognitive impairment in liver transplanted patients with transthyretin-related hereditary amyloid polyneuropathy.

INTRODUCTION AND AIM: Hereditary transthyretin-related amyloidosis (ATTR-FAP) is characterized by a progressive neuropathy, cardiomyopathy, nephropathy and ocular disease. More than 90% of amyloidogenic transthyretin is produced by the liver; however, this protein is also synthesized in the choroid plexus. Although some patients have transitory neurologic events, the impact on cognition is still unknown. The aim was to study the cognitive performance of ATTR-FAP V30M patients with long disease course. METHODS: A prospective observational study of a consecutive sample of patients with 10 or more years of disease duration was conducted. All patients underwent an extensive neuropsychological evaluation. RESULTS: Sixteen patients were included, with a mean age of 53 years and mean duration of disease of 18 years. All had been submitted to liver transplantation. The functional status was not incapacitating in the majority, with 75% needing at most a stick to walk and 38% still actively working. The neuropsychological evaluation disclosed episodic memory impairments in 31% and executive dysfunction in 25% of patients. CONCLUSIONS: These novel findings suggest that cognitive dysfunction can be a delayed manifestation of hereditary transthyretin-related amyloidosis. The putative relation of cognitive dysfunction with transthyretin-amyloid deposition can provide another model to study the amyloid hypothesis of cognitive impairment.

Laterality of Pneumonia in Acute Stroke.

BACKGROUND/AIMS: Previous studies demonstrated an alteration of diaphragmatic excursion on the paretic side after stroke; however, it is unclear if this change has clinical repercussions. We aimed to determine if there was an association between the paretic side and the laterality of pneumonia after stroke. METHODS: A retrospective analysis of a consecutive cohort of patients admitted to a stroke unit from 2008 to May 2016 was performed. Patients with the diagnosis of acute stroke and pneumonia were included. The laterality of pneumonia was determined through the blinded observation of chest X-rays. Fisher's exact test was applied to study the association between the side of paresis and pneumonia. RESULTS: One hundred and five patients were included. Sixty one percent (n = 64) had an ischemic stroke, 39% (n = 41) had brain hemorrhage, and 49.5% (n = 52) had right side paresis. We did not find in general an association between the side of paresis and the side of pneumonia (p = 1.00); however, we found a statistically significant association in patients with severe lower limb paresis (Medical Research Council, MRC ≤2; p = 0.035). CONCLUSION: We found an association between severe paresis of the lower limb (MRC ≤2) and ipsilateral pneumonia. We hypothesize that the proximity between the diaphragmatic and inferior limb corticospinal pathways could be the reason for this association.

Disfunción de los nervios craneales IV y V como manifestaciones iniciales de siderosis superficial del sistema nervioso central / IV and V cranial nerves dysfunction as initial manifestations of superficial siderosis of the central nervous system

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