Concomitant Vitamin B1 and Vitamin B12 Deficiency Mimicking Thrombotic Thrombocytopenic Purpura.

Vitamin B12 deficiency-induced pseudo-thrombotic thrombocytopenic purpura (pseudo-TTP) is a rare condition. In reported literature, most cases were due to pernicious anemia (confirmed by the presence of anti-parietal cells or anti-intrinsic factor antibodies). Nutritional vitamin B12 deficiency causing pseudo-TTP is a much rarer entity. Differentiating thrombotic thrombocytopenic purpura (TTP) cases from pseudo-TTP (from any cause) should be done as soon as possible since the etiology, treatment, and outcome are different. Hematological findings from pseudo-TTP (when associated with vitamin B12 deficiency) respond to B12 replacement but do not respond to plasmapheresis. Neurological symptoms are one of the criteria for TTP, and altered mentation or psychosis in these cases is presumed secondary to either TTP or vitamin B12 deficiency. However, neurological symptoms are more characteristic of TTP rather than pseudo-TTP. In the rarer subsets of patients concerned with nutritional deficiency and neuropsychiatric symptoms, prompt consideration of concomitant vitamin B1 deficiency and Wernicke encephalopathy is essential. Immediate empiric treatment with high-dose IV thiamine should be started. If unrecognized and left untreated, thiamine deficiency can cause rapid progression to irreversible neurological symptoms, coma, and death, despite hematological improvement with B12 replacement. We report a rare case of concomitant vitamin B12 and vitamin B1 deficiency presenting with confusion, severe hemolytic anemia, acute renal failure, diarrhea, and thrombocytopenia mimicking TTP.

EEG-EMG Correlation Analysis with Linear and Nonlinear Coupling Methods Across Four Motor Tasks.

Correlation between brain and muscle signal is referred to as functional coupling. The amount of correlation between two signals greatly depends on the motor task performance. In this study, we designed the experimental paradigm with four types of motor tasks such as real hand grasping movement (RM), movement intention (Inten), motor imagery (MI) and only looking at virtual hand in three dimensional head mounted display (OL). We aimed to investigate EEG-EMG correlation with linear and nonlinear coupling methods. The results proved that high correlation could be occurred in RM and Inten tasks rather than MI and OL tasks in both linear and nonlinear methods. High coherence occurred in beta and gamma bands of RM and Inten tasks whereas no coherence was detected in MI and OL tasks. In terms of nonlinear correlation, the high mutual information was detected in RM and Inten tasks. There was slight mutual information in MI and OL tasks. The results showed that the coherence in the contralateral brain cortex was higher than in the ipsilateral motor cortex during motor tasks. Furthermore, the amount of EEG-EMG functional coupling changed according to the motor task executed.

Electroencephalogram-Electromyogram Functional Coupling and Delay Time Change Based on Motor Task Performance.

Synchronous correlation brain and muscle oscillations during motor task execution is termed as functional coupling. Functional coupling between two signals appears with a delay time which can be used to infer the directionality of information flow. Functional coupling of brain and muscle depends on the type of muscle contraction and motor task performance. Although there have been many studies of functional coupling with types of muscle contraction and force level, there has been a lack of investigation with various motor task performances. Motor task types play an essential role that can reflect the amount of functional interaction. Thus, we examined functional coupling under four different motor tasks: real movement, intention, motor imagery and movement observation tasks. We explored interaction of two signals with linear and nonlinear information flow. The aim of this study is to investigate the synchronization between brain and muscle signals in terms of functional coupling and delay time. The results proved that brain-muscle functional coupling and delay time change according to motor tasks. Quick synchronization of localized cortical activity and motor unit firing causes good functional coupling and this can lead to short delay time to oscillate between signals. Signals can flow with bidirectionality between efferent and afferent pathways.