RESUMO
OBJECTIVE: Visual snow (VS) is a rare clinical entity in neuro-ophthalmology. It is described as the presence of flickering dots affecting the whole visual field, often compared by patients to snow or pixelated television static. Importantly, it can be an alarming symptom for many patients, lowering their quality of life. Our purpose is to increase awareness of this disease, because many healthcare professionals have difficulty identifying symptoms as the nature of the condition is subjective. In this review, we aimed to describe the updates in the etiology and treatment of visual snow. We searched for articles in English, presenting original data and published after December 2019. Different studies show inconsistent data. Neuroimaging studies found, among other things, hypermetabolism of the lingual gyrus, increased gray matter in different brain areas, and altered connectivity in visual pathways. However, these findings were not present in all patients. According to the literature, among the most effective drugs is lamotrigine. Unfortunately, it also carries a risk of worsening the symptoms. It is crucial to remember that VS can be worsened or induced by alcohol, recreational drugs, and certain medication. In terms of treatment, nonpharmacological approaches such as color filters and repetitive Transcranial Magnetic Stimulation were also used. INTERPRETATION: Further studies are needed to understand the nature of VS fully. Even though the pathophysiology and effective treatment of the condition remains unknown, expanding the knowledge about visual snow can impact the comfort of patients.
RESUMO
Deficiency in dopaminergic system function may be one of the hypothetical reasons of the frailty syndrome but its role still remains unclear. The aim of our study was to assess the frailty phenotype prevalence in geriatric inpatients with mild parkinsonian signs (MPS) and to investigate levodopa test in the frail patients with MPS. We examined 118 participants: 90 with MPS and 28 in control group (without MPS). The frailty syndrome presence was evaluated by the Fried criteria. Deficiency in dopaminergic system function was assessed by one of the modifications of an acute levodopa challenge test (LCT): in MPS group every patient was examined by performing Up and Go Test and also Step Test before and 3 h after taking 125 mg of Madopar (levodopa + benserazide). Sixty-nine study subjects (58%) met criteria for frailty. Fifty-five participants in MPS group (61.1% of MPS group) and fourteen (50%) in control group. All of the patients that scored positive in walk speed criterion of frailty were frail. When all MPS patients were considered, the number of components scored positive for frailty was directly related to the walk speed (r = -0.70, p < 0.0001). In MPS group LCT scores were significantly higher for frailty patients compared to non-frailty (p = 0.0027). When all MPS patients were considered, the number of components scored positive for frailty was directly related LCT score (r = 0.37, p = 0.0004). There was a relationship between LCT and walk speed (r = -0.31, p = 0.0032). Our observations provide new information about the relationship between frailty and MPS, suggest the need for increased awareness of frailty in MPS patients and conversely. Our study provides data for a discussion on pathophysiological background of the frailty syndrome (FS), emphasizing the theories of the important impact of dopaminergic system deficit and encourages further research on the role of LCT in measuring it.
