Transient Global Amnesia Recurrence: Prevalence and Risk Factor Meta-analysis.

Background and Objectives: Transient global amnesia (TGA) is an acute amnestic disorder with unclear pathophysiology. Although considered a benign phenomenon, the possibility of a recurrence is a major concern for the patient. Our objective is to identify the prevalence and risk factors of relapse to help clinicians counsel patients about it. Methods: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidance, we screened 1,658 studies from MEDLINE, Lilacs, and Embase databases, published from 1985 to April 2021, in English or Spanish. We included 36 observational case-control and cohort studies that included patients with TGA according to the Caplan or Hodges and Warlow diagnostic criteria. We performed a meta-analysis with a random effect model for proportions and calculation of odds ratio (OR) for identified risk factors. Methodological quality was assessed according to the Newcastle-Ottawa scale. Results: We identified 4,514 TGA cases and 544 recurrence events (12.73%). A follow-up had no effect on its variance. We identified a statistically significant association between recurrence and sexual activity as a trigger, a personal history or current state of migraine and depression (OR 1,481 95% CI [1.0341-2.1222] p = 0.04; OR = 2.0795 95% CI [1.3892-3.1128] p = 0.003; and OR = 4.4871 95% CI [1.890-10.651] p = 0.0288, respectively). Discussion: The analysis showed that approximately 1 of 8 participants may experience recurrence, with an increased risk in the case of a history or current state of migraine, depression, or sexual intercourse before the event. A personal history of migraine and depression was associated with 2 and 4 times risk, respectively.

Correlation between 99mTc-TRODAT-1 SPECT and 18F-FDOPA PET in patients with Parkinson's disease: a pilot study.

OBJECTIVE: To determine whether technetium-99m-labeled tropane derivative single-photon emission computed tomography (99mTc-TRODAT-1 SPECT) provides results comparable to those of the less widely available, less accessible tool fluorine-18-labeled fluorodopa positron-emission tomography (18F-FDOPA PET) in the setting of a movement disorders clinic. MATERIALS AND METHODS: In this prospective pilot study, eight subjects with a clinical diagnosis of Parkinson's disease were randomly selected from among patients under treatment at a movement disorders clinic and submitted to 99mTc-TRODAT-1 SPECT and 18F-FDOPA PET. The results were read by two experienced observers, and a semiquantitative analysis was performed. RESULTS: The visual and semiquantitative analyses were concordant for all studies, showing that radiotracer uptake in the contralateral striatum on the most affected side was lower when 99mTc-TRODAT-1 SPECT was employed. The semiquantitative analysis demonstrated a significant correlation between 18F-FDOPA PET and 99mTc-TRODAT-1 SPECT (r = 0.73; p < 0.01). CONCLUSION: It appears that 99mTc-TRODAT-1 SPECT is a valid option for the study of dopaminergic function in a clinical setting.

OBJETIVO: Determinar se a 99mTc-TRODAT-1 SPECT fornece resultados comparáveis aos da 18F-FDOPA PET, ferramenta menos acessível e menos amplamente disponível, no contexto de uma clínica de distúrbios do movimento. MATERIAIS E MÉTODOS: Neste estudo prospectivo, oito indivíduos com diagnóstico clínico de doença de Parkinson foram selecionados aleatoriamente entre pacientes em tratamento em uma clínica de distúrbios do movimento e submetidos a 99mTc-TRODAT-1 SPECT e 18F-FDOPA PET. Os resultados foram lidos por dois observadores experientes e uma análise semiquantitativa foi realizada. RESULTADOS: As análises visual e semiquantitativa foram concordantes para todos os estudos, mostrando que a captação do radiotraçador no estriado contralateral do lado mais afetado foi menor quando a 99mTc-TRODAT-1 SPECT foi empregada. A análise semiquantitativa demonstrou uma correlação significativa entre 18F-FDOPA PET e 99mTc-TRODAT-1 SPECT (r = 0,73; p < 0,01). CONCLUSÃO: A 99mTc-TRODAT-1 SPECT parece ser uma opção válida para o estudo da função dopaminérgica em um ambiente clínico.

Correlation between 99mTc-TRODAT-1 SPECT and 18F-FDOPA PET in patients with Parkinson's disease: a pilot study / Correlação entre 99mTc-TRODAT-1 SPECT e 18F-FDOPA PET em pacientes com doença de Parkinson: um estudo piloto

Abstract Objective: To determine whether technetium-99m-labeled tropane derivative single-photon emission computed tomography (99mTc-TRODAT-1 SPECT) provides results comparable to those of the less widely available, less accessible tool fluorine-18-labeled fluorodopa positron-emission tomography (18F-FDOPA PET) in the setting of a movement disorders clinic. Materials and Methods: In this prospective pilot study, eight subjects with a clinical diagnosis of Parkinson's disease were randomly selected from among patients under treatment at a movement disorders clinic and submitted to 99mTc-TRODAT-1 SPECT and 18F-FDOPA PET. The results were read by two experienced observers, and a semiquantitative analysis was performed. Results: The visual and semiquantitative analyses were concordant for all studies, showing that radiotracer uptake in the contralateral striatum on the most affected side was lower when 99mTc-TRODAT-1 SPECT was employed. The semiquantitative analysis demonstrated a significant correlation between 18F-FDOPA PET and 99mTc-TRODAT-1 SPECT (r = 0.73; p < 0.01). Conclusion: It appears that 99mTc-TRODAT-1 SPECT is a valid option for the study of dopaminergic function in a clinical setting.

Resumo Objetivo: Determinar se a 99mTc-TRODAT-1 SPECT fornece resultados comparáveis aos da 18F-FDOPA PET, ferramenta menos acessível e menos amplamente disponível, no contexto de uma clínica de distúrbios do movimento. Materiais e Métodos: Neste estudo prospectivo, oito indivíduos com diagnóstico clínico de doença de Parkinson foram selecionados aleatoriamente entre pacientes em tratamento em uma clínica de distúrbios do movimento e submetidos a 99mTc-TRODAT-1 SPECT e 18F-FDOPA PET. Os resultados foram lidos por dois observadores experientes e uma análise semiquantitativa foi realizada. Resultados: As análises visual e semiquantitativa foram concordantes para todos os estudos, mostrando que a captação do radiotraçador no estriado contralateral do lado mais afetado foi menor quando a 99mTc-TRODAT-1 SPECT foi empregada. A análise semiquantitativa demonstrou uma correlação significativa entre 18F-FDOPA PET e 99mTc-TRODAT-1 SPECT (r = 0,73; p < 0,01). Conclusão: A 99mTc-TRODAT-1 SPECT parece ser uma opção válida para o estudo da função dopaminérgica em um ambiente clínico.

Quantification methods comparison in brain 18F-FDOPA PET.

18F-FDOPA PET is one of the most widely used molecular imaging techniques to assess presynaptic dopaminergic activity. A variety of analytical methods have been developed to quantify 18F-FDOPA PET images and in most, the striatal-to-occipital ratio (SOR) is used as a quantitative parameter. A manual strategy is typically used for quantification purposes, which can have some caveats, being time-consuming and having some inter-rater variability. In the present study we aimed to test whether automated quantification methods can provide an efficient alternative to manual quantification to overcome its limitations and compare each method's capacity to discriminate between normal and abnormal subjects. 18F-FDOPA PET images of 60 subjects were analyzed and quantified with one manual and two automated methods. SUVRs were obtained for caudate and putamen nucleus in both cases. We were able to reach the same level of discrimination with manual and automated strategies, and a threshold for normal/abnormal discrimination could be obtained. We believe automated strategies for VOI quantification can help molecular imaging physicians in the process of interpretation of studies, making the process faster, yet reliable and objective.

Headache and Treatment of Unruptured Intracranial Aneurysms.

BACKGROUND AND PURPOSE: The relationship between unruptured intracranial aneurysms (UIAs) and chronic headache and the impact of aneurysm treatment on headache outcome are controversial. The aim of this study was to determine clinical features of a supposedly primary headache in patients with UIA. We also assessed changes in headache characteristics after UIA treatment. METHODS: We examined clinical and imaging data of patients in whom a UIA was diagnosed during diagnostic workup of a suspected primary headache. Medical records were reviewed and personal telephone follow-ups were performed after UIA treatment to assess changes in the frequency and intensity of the headache. RESULTS: Forty-two patients (76%) reported a substantial improvement in headache frequency and intensity after UIA treatment. Forty-five patients (81%) reported a decrease in headache frequency from a median of 8 days/month before treatment to 1 day/month after treatment (95% confidence interval [CI] 81-83, P < .001). The average intensity in an analog pain scale was 7.7 ± 1.6 before treatment and 5.6 ± 2.4 after treatment (P < .001). Higher headache frequency was associated with a greater odd of improvement after treatment (odds ratio 1.12, 95% CI 1.0-1.26, P = .03). No associations were found between the type of headache, type of treatment (endovascular versus surgical), number, size, or localization of the aneurysms and the response to treatment. CONCLUSIONS: The treatment of UIA had a robust beneficial effect on previous headache. Although a "placebo" effect of aneurysm treatment cannot be ruled out, these results suggest a potential association between UIA and certain chronic headaches usually considered to be primary.

Bilateral Paramedian Thalamic Infarction.

INTRODUCTION: Rarely, both paramedian thalami receive arterial blood flow from a single unilateral vessel arising from the first segment of 1 posterior cerebral artery. This artery has received the name of artery of Percheron (AP). There is no consensus regarding the true prevalence of this anatomical variant. Bilateral paramedian thalamic infarcts are uncommon (0.1% to 2% of ischemic strokes). The main cause is the occlusion of the AP due to cardioembolism. Diffusion-weighted magnetic resonance imaging demonstrates the lesion in the acute setting. MATERIALS AND METHODS: From September 2004 to October 2011, we identified 5 patients who had bilateral paramedian thalamic infarcts. We describe clinical findings and diagnostic imaging patterns observed in these cases and review the literature. RESULTS: Three men and 2 women with bilateral paramedian thalamic infarction probably due to occlusion of AP are described. Mean age at presentation was 58±24 years. Magnetic resonance imaging showed the lesion in all patients. Four patients presented loss of consciousness as initial symptom. Only 1 patient evidenced mesencephalic extension of the infarct on magnetic resonance imaging, although 4 presented abnormal ocular signs. No patients received intravenous thrombolisis because of delayed diagnosis. All patients were discharged home. A 90-year-old woman recovered completely and the other 4 subjects persisted with cognitive symptoms and gaze abnormalities. CONCLUSIONS: Clinical presentation and imaging patterns described in this group of patients were similar to published data. High level of suspicion based on clinical and imaging findings is essential for early diagnosis of this rare condition. None of our patients had an early diagnosis of acute ischemic stroke and received proper thrombolytic treatment.

Lack of maintenance of gait pattern as measured by instrumental methods suggests psychogenic gait.

Fluctuation is a common feature of all psychogenic gait disorder (PGD) patterns. Whether this fluctuation involves only the degree of impairment or whether it affects the gait pattern itself remains an interesting question. We hypothesize that, on repeated measurements, both normal and abnormal gait may present quantitative differences while maintaining their basic underlying pattern; conversely, in psychogenic gait, the basic pattern appears not to be preserved. Using an optoelectronic system, data acquired from 19 normal subjects and 66 patients were applied to train a neural network (NN) and subsequently classify gait patterns into four different groups (normal, ataxic, spastic-paraparetic and parkinsonian). Five patients who fulfilled clinical criteria for psychogenic gait and six controls were then prospectively evaluated on two separate occasions, three months apart. Normal controls and ataxic, parkinsonian or spastic patients were correctly identified by the NN, and categorized within the corresponding groups at baseline as well as at a three-month follow-up evaluation. NN analysis showed that after three months, no PGD patient preserved the gait pattern detected at baseline, even though this finding was not clinically apparent. Modification of gait pattern detected by repeated kinematic measurement and NN analysis could suggest the presence of PGD, particularly in difficult-to-diagnose cases.