Heart Failure Awareness Survey in a Turkish Population: HFAS-TR.

OBJECTIVE: Heart failure is a leading cause of death and the most common diagnosis leading to hospitalization. Its awareness is lower than that of other cardiovascular diseases, both in the general population and among patients with heart failure (HF). This study aimed to establish the current level of knowledge about HF in patients with HF with reduced ejection fraction (HFrEF) and mildly reduced ejection fraction (HFmrEF) in Türkiye. METHODS: This questionnaire-based survey study is multicenter, conducted across 34 centers from December 2021 to July 2022. We performed a survey consisting of two sets of questions focusing on individual characteristics of the patients and HF-related knowledge. RESULTS: The study included a total of 2,307 outpatient HF patients, comprising 70.5% males and 29.5% females with a mean age of 64.58 ± 13 (56-74) years and a mean body mass index value of 32.5 ± 10 kg/m2. HFrEF and HFmrEF were determined in 74.7% and 25.3% of patients, respectively. Thirty percent of the patients were unaware that they had HF. While 28.7% of the patients thought that they had sufficient information about HF, 71.3% believed they lacked adequate knowledge. In the study, 25.2% of the participants identified dyspnea, 22% identified tiredness, and 25.4% identified leg edema as the most common symptoms of HF. Only 27.4% of patients recognized all three typical symptoms of HF. CONCLUSION: We found that the study population's knowledge about HF symptoms and the nature of the disease was poor. Educational and awareness activities are necessary to optimize outcomes and benefits.

Evaluation of the correlation of neutrophil/lymphocyte ratio with prognostic classification systems in papillary thyroid carcinoma patients.

We aimed to evaluate the use of cost-effective NLR (Neutrophil Lymphocyte Ratio) in determining the prognosis and recurrence risk of thyroid papillary carcinoma patients. This retrospective, cross-sectional and single-center study was carried out in the Department of General Surgery, Istanbul Gaziosmanpasa Training and Research Hospital. Between 2018 and 2021, who were diagnosed with papillary thyroid cancer and underwent total thyroidectomy, and patients who underwent total thyroidectomy due to multinodular goiter were analyzed. For patients in the malignancy group, the NLR cutoff value was determined as 1.73, the sensitivity was calculated as 51.77% and the specificity as 86.15%. NLR in the malignant group was found to be 9.5 times higher than the NLR in the control group (Odds Ratio: 9.5). A statistically significant difference was found between NLR and papillary thyroid carcinoma prognostic classification systems (AJCC/TNM, AMES, and MACIS). NLR medians differ according to ATA recurrence risk classification (P = .020). According to the results we obtained in our study, we believe that cost-effective NLR can be a useful indicator in terms of predicting malignancy in a patient with thyroid nodule and in determining the prognosis and risk of recurrence in patients with thyroid papillary carcinoma.

Correlation between breast and axillary pathologic complete response after neoadjuvant chemotherapy in breast cancer.

AIM: The aim of this study was to evaluate the correlation of the pathological response in breast tissue and the axilla of patients with breast cancer who underwent surgery following neoadjuvant chemotherapy. METHOD: This retrospective cohort study included patients with T1-4, N1-3, M0 breast cancer who underwent surgery following neoadjuvant chemotherapy at Gaziosmanpasa Training and Research Hospital between 2013 and 2022. The response of the breast tissue to chemotherapy was evaluated with the Miller-Payne grading system, and the response of the axillary lymph nodes to chemotherapy was evaluated with the Pinder grading system. The patients were grouped histopathologically as luminal A, luminal B, Her-2 enriched, or triple negative breast cancer (TNBC). RESULTS: The study was completed with 140 patients. Pathological complete response (pCR) was seen in the breast in 40 patients and in the axilla in 34. Of the patients with pCR in the breast, pCR was also determined in the axilla in 45%. In the patients with pCR in both the breast and axilla, Her-2 enriched subtype, estrogen receptor negativity, progesterone receptor negativity, Her-2 neu positivity, and Ki-67 level >25% were determined to be effective (p<0.05). Her-2 neu positivity was evaluated as statistically significant in the development of pCR in both the breast and axilla (OR: 4.06, 95% CI:1.2-13.6, p=0.023). CONCLUSION: The development of pCR in the breast, especially in the Her-2 enriched subgroup, can be accepted as a predictive factor for the evaluation of axillary response in patients with breast cancer. The least compatibility was seen in the luminal A subgroup. KEY WORDS: Breast cancer, Miller-Payne, Neoadjuvant chemotherapy Pathological complete response, Pinder.

Predictors of coronary tortuosity in patients with chronic coronary syndrome.

Aim    Coronary artery tortuosity is a common coronary angiographic finding. This tortuosity can cause myocardial ischemia even in the absence of significant coronary artery stenosis. Our aim was to compare the demographic, clinical and echocardiographic features of patients with chronic coronary syndrome (CCS) and with and without coronary artery tortuosity.Material and methods    361 patients who underwent elective coronary angiography (CAG) due to CCS were included in the study. These patients divided into two groups, those with coronary tortuosity (Group 1) and those without (Group 2). Univariable and multivariable logistic regression analysis was performed to identify predictors associated with coronary artery tortuosity.Results    The mean age of the 361 CCS patients (44 % female; 56 % male) was 56.7±11.5 years. In the univariable regression analysis, age, female sex, hypertension (HT), PR interval, QTc interval, ST / T segment changes, left ventricle diastolic dysfunction (LVDD), left ventricle hypertrophia (LVH) were identified as predictors of coronary tortuosity. In the multivariable regression analysis, age (OR: 1.059; 95 %CI: 1.032-1.087, p<0.001) and hypertension (OR: 0.484; 95 %CI: 0.278-0.843, p=0.01) were identified as independent predictors of coronary tortuosity.Conclusion    Coronary artery tortuosity is an angiographic finding that develops as a result of adaptive mechanisms in the heart and can cause myocardial ischemia. Predictors of coronary artery tortuosity in patients with CCS were long PR and QTc intervals, ST / T segment changes, LVH, LVDD, advanced age, and female gender. Evaluation of these demographic, electrocardiographic, and echocardiographic data may help clinicans to anticipate coronary artery tortuosity in patients with CCS and to be precautious for PCI.

The Definition of Sarcomeric and Non-Sarcomeric Gene Mutations in Hypertrophic Cardiomyopathy Patients: A Multicenter Diagnostic Study Across Türkiye.

BACKGROUND: Hypertrophic cardiomyopathy is a common genetic heart disease and up to 40%-60% of patients have mutations in cardiac sarcomere protein genes. This genetic diagnosis study aimed to detect pathogenic or likely pathogenic sarcomeric and non-sarcomeric gene mutations and to confirm a final molecular diagnosis in patients diagnosed with hypertrophic cardiomyopathy. METHODS: A total of 392 patients with hypertrophic cardiomyopathy were included in this nationwide multicenter study conducted at 23 centers across Türkiye. All samples were analyzed with a 17-gene hypertrophic cardiomyopathy panel using next-generation sequencing technology. The gene panel includes ACTC1, DES, FLNC, GLA, LAMP2, MYBPC3, MYH7, MYL2, MYL3, PLN, PRKAG2, PTPN11, TNNC1, TNNI3, TNNT2, TPM1, and TTR genes. RESULTS: The next-generation sequencing panel identified positive genetic variants (variants of unknown significance, likely pathogenic or pathogenic) in 12 genes for 121 of 392 samples, including sarcomeric gene mutations in 30.4% (119/392) of samples tested, galactosidase alpha variants in 0.5% (2/392) of samples and TTR variant in 0.025% (1/392). The likely pathogenic or pathogenic variants identified in 69 (57.0%) of 121 positive samples yielded a confirmed molecular diagnosis. The diagnostic yield was 17.1% (15.8% for hypertrophic cardiomyopathy variants) for hypertrophic cardiomyopathy and hypertrophic cardiomyopathy phenocopies and 0.5% for Fabry disease. CONCLUSIONS: Our study showed that the distribution of genetic mutations, the prevalence of Fabry disease, and TTR amyloidosis in the Turkish population diagnosed with hypertrophic cardiomyopathy were similar to the other populations, but the percentage of sarcomeric gene mutations was slightly lower.

[Temporary and persistent visual phenomena in neurology]. / Passagere und anhaltende visuelle Phänomene in der Neurologie.

Temporary and persistent visual phenomena are a frequent reason for a neurological presentation. The diagnosis can usually be made with the help of a structured anamnesis with determination of the time of onset, the course and symptoms as well as the monocular vs. binocular manifestation. The visual aura in migraine is certainly the most frequent entity to be differentiated. In particular, persistent visual phenomena such as visual snow syndrome, hallucinogen persisting perception disorder and the Charles Bonnet syndrome (CBS) seem to be underdiagnosed in clinical practice for various reasons and are probably not that rare. Instrumental diagnostics are mostly used for exclusion diagnostics and are a component of a complete patient education, but can be indicative for certain questions (CBS, epilepsy). This article presents the most frequent visual phenomena from the neurological practice and their differential diagnoses, guided by a case history.

The effect of the Covid 19 pandemic on the number of patients treated for acute and complex acute appendicitis.

AIM: The aim of this study was to compare the increase in the number of complicated cases in patients who underwent surgery for acute appendicitis during the COVID-19 pandemic and the previous year. MATERIAL AND METHODS: A retrospective examination was made of the files of patients who presented at the Emergency Department and were diagnosed with acute appendicitis and underwent surgery within 24 hours or were followed up between 11 March and 1 June 2020 during the COVID-19 pandemic, and in the same period in the previous year. The patients in the pandemic period were named the pandemic group (PG) and the patients from the previous year, the control group (CG). The definition of complicated appendicitis included peri-appendicular abscess and perforated appendix. RESULTS: The number of patients in the PG was 38.33% lower than in the CG. The duration of symptoms was 2 days in the PG and 1 day in the CG, and the difference was statistically significant (p=0.001). The mean neutrophil count was determined to be higher in the PG than in the CG (p=0.018). The rate of perforated appendix was determined to be 10.9 higher in the PG than in the CG. CONCLUSION: The number of patients presenting at the Emergency Department reduced during the pandemic, especially during periods of lockdown, and it was seen that fewer but more complicated patients presented at our centre. KEY WORDS: Acute appendicitis, COVID-19, Perforation.

Frontal QRS/T angle can predict mortality in COVID-19 patients.

AIMS: The frontal QRS-T (fQRS) angle has been investigated in the general population, including healthy people and patients with heart failure. The fQRS angle can predict mortality due to myocarditis, ischaemic and non-ischaemic cardiomyopathies, idiopathic dilated cardiomyopathy, and chronic heart failure in the general population. Moreover, no studies to date have investigated fQRS angle in coronavirus disease 2019 (COVID-19) patients. Thus, the purpose of this retrospective multicentre study was to evaluate the fQRS angle of COVID-19 patients to predict in-hospital mortality and the need for mechanical ventilation. METHODS AND RESULTS: An electrocardiogram was performed for 327 COVID-19 patients during admission, and the fQRS angle was calculated. Mechanical ventilation was needed in 119 patients; of them, 110 died in the hospital. The patients were divided into two groups according to an fQRs angle >90° versus an fQRS angle ≤90°. The percentages of mortality and the need for mechanical ventilation according to fQRS angle were 67.8% and 66.1%, respectively, in the fQRs >90° group and 26.1% and 29.9% in the fQRS ≤90°group. Heart rate, oxygen saturation, fQRS angle, estimated glomerular filtration rate, and C-reactive protein level were predictors of mortality on the multivariable analysis. The mortality risk increased 2.9-fold on the univariate analysis and 1.6-fold on the multivariate analysis for the fQRS >90° patient group versus the fQRS ≤90° group. CONCLUSION: In conclusion, a wide fQRS angle >90° was a predictor of in-hospital mortality and associated with the need for mechanical ventilation among COVID-19 patients.

White matter volume loss drives cortical reshaping after thalamic infarcts.

OBJECTIVE: The integration of somatosensory, ocular motor and vestibular signals is necessary for self-location in space and goal-directed action. We aimed to detect remote changes in the cerebral cortex after thalamic infarcts to reveal the thalamo-cortical connections necessary for multisensory processing and ocular motor control. METHODS: Thirteen patients with unilateral ischemic thalamic infarcts presenting with vestibular, somatosensory, and ocular motor symptoms were examined longitudinally in the acute phase and after six months. Voxel- and surface-based morphometry were used to detect changes in vestibular and multisensory cortical areas and known hubs of central ocular motor processing. The results were compared with functional connectivity data in 50 healthy volunteers. RESULTS: Patients with paramedian infarcts showed impaired saccades and vestibular perception, i.e., tilts of the subjective visual vertical (SVV). The most common complaint in these patients was double vision or vertigo / dizziness. Posterolateral thalamic infarcts led to tilts of the SVV and somatosensory deficits without vertigo. Tilts of the SVV were higher in paramedian compared to posterolateral infarcts (median 11.2° vs 3.8°). Vestibular and ocular motor symptoms recovered within six months. Somatosensory deficits persisted. Structural longitudinal imaging showed significant volume reduction in subcortical structures connected to the infarcted thalamic nuclei (vestibular nuclei region, dentate nucleus region, trigeminal root entry zone, medial lemniscus, superior colliculi). Volume loss was evident in connections to the frontal, parietal and cingulate lobes. Changes were larger in the ipsilesional hemisphere but were also detected in homotopical regions contralesionally. The white matter volume reduction led to deformation of the cortical projection zones of the infarcted nuclei. CONCLUSIONS: White matter volume loss after thalamic infarcts reflects sensory input from the brainstem as well the cortical projections of the main affected nuclei for sensory and ocular motor processing. Changes in the cortical geometry seem not to reflect gray matter atrophy but rather reshaping of the cortical surface due to the underlying white matter atrophy.

Reorganization of sensory networks after subcortical vestibular infarcts: A longitudinal symptom-related voxel-based morphometry study.

BACKGROUND AND PURPOSE: We aimed to delineate common principles of reorganization after infarcts of the subcortical vestibular circuitry related to the clinical symptomatology. Our hypothesis was that the recovery of specific symptoms is associated with changes in distinct regions within the core vestibular, somatosensory, and visual cortical and subcortical networks. METHODS: We used voxel- and surface-based morphometry to investigate structural reorganization of subcortical and cortical brain areas in 42 patients with a unilateral, subcortical infarct with vestibular and ocular motor deficits in the acute phase. The patients received structural neuroimaging and clinical monitoring twice (acute phase and after 6 months) to detect within-subject changes over time. RESULTS: In patients with vestibular signs such as tilts of the subjective visual vertical (SVV) and ocular torsion in the acute phase, significant volumetric increases in the superficial white matter around the parieto-opercular (retro-)insular vestibular cortex (PIVC) were found at follow-up. In patients with SVV tilts, spontaneous nystagmus, and rotatory vertigo in the acute phase, gray matter volume decreases were located in the cerebellum and the visual cortex bilaterally at follow-up. Patients with saccade pathology demonstrated volumetric decreases in cerebellar, thalamic, and cortical centers for ocular motor control. CONCLUSIONS: The findings support the role of the PIVC as the key hub for vestibular processing and reorganization. The volumetric decreases represent the reciprocal interaction of the vestibular, visual, and ocular motor systems during self-location and egomotion detection. A modulation in vestibular and ocular motor as well as visual networks was induced independently of the vestibular lesion site.

Evaluation of treatment response and symptom progression in 400 patients with visual snow syndrome.

AIMS: To gather information on useful medications to treat visual snow syndrome (VSS) as well as to validate an instrument to assess its clinical severity and the course of the disorder over time. METHODS: Four hundred patients with VSS were included in this web-based prospective questionnaire study. All subjects completed a treatment questionnaire and a clinical diary. The first allowed evaluation of the effects of previous medications on visual snow, while the second measured VSS symptoms daily over the course of 30 days. RESULTS: Patients commonly reported previous use of medications such as antidepressants, antiepileptics, antibiotics and benzodiazepines. However, none of these drug classes was beneficial for the majority of patients. Recreational drugs and alcohol worsened visual snow symptoms in several reports. Vitamins and benzodiazepines had high therapeutic ratios, although in most cases they did not change the course of VSS.The monthly diary confirmed that the static in VSS is a consistent symptom over time. It also showed that indoor and fluorescent lights have a worse effect on symptoms when compared with natural outdoor lighting. CONCLUSIONS: The study confirms clinical experience that medications are generally ineffective in VSS, with the exception of vitamins and perhaps benzodiazepines, which could be beneficial in some patients. The 30-day diary represents a useful tool to measure symptom progression over time, which could be used in future trials on VSS.

Diagnosis and follow-up evaluation of central nervous system vasculitis: an evaluation of vessel-wall MRI findings.

OBJECTIVE: To approach the clinical value of MRI with vessel wall imaging (VWI) in patients with central nervous system vasculitis (CNSV), we analyzed patterns of VWI findings both at the time of initial presentation and during follow-up. METHODS: Stenoocclusive lesions, vessel-wall contrast enhancement (VW-CE) and diffusion-restricted lesions were analyzed in patients with a diagnosis of CNSV. On available VWI follow-up, progression, regression or stability of VW-CE were evaluated and correlated with the clinical status. RESULTS: Of the 45 patients included, 28 exhibited stenoses visible on MR angiography (MRA-positive) while 17 had no stenosis (MRA-negative). VW-CE was found in 2/17 MRA-negative and all MRA-positive patients (p < 0.05). 79.1% (53/67) of stenoses showed VW-CE. VW-CE was concentric in 88.3% and eccentric in 11.7% of cases. Diffusion-restricted lesions were found more frequently in relation to stenoses with VW-CE than without VW-CE (p < 0.05). 48 VW-CE lesions in 23 patients were followed over a median time of 239.5 days. 13 VW-CE lesions (27.1%) resolved completely, 14 (29.2%) showed partial regression, 17 (35.4%) remained stable and 4 (8.3%) progressed. 22/23 patients received immunosuppressive therapy for the duration of follow-up. Patients with stable or progressive VW-CE were more likely (p < 0.05) to have a relapse (14/30 cases) than patients with partial or complete regression of VW-CE (5/25 cases). CONCLUSION: Concentric VW-CE is a common finding in medium/large-sized vessel CNSV. VW-CE might represent active inflammation in certain situations. However, follow-up VWI findings proved ambiguous as persisting VW-CE despite immunosuppressive therapy and clinical remission was a frequent finding.

Patients with chronic pain exhibit individually unique cortical signatures of pain encoding.

Chronic pain is characterised by an ongoing and fluctuating intensity over time. Here, we investigated how the trajectory of the patients' endogenous pain is encoded in the brain. In repeated functional MRI (fMRI) sessions, 20 patients with chronic back pain and 20 patients with chronic migraine were asked to continuously rate the intensity of their endogenous pain. Linear mixed effects models were used to disentangle cortical processes related to pain intensity and to pain intensity changes. At group level, we found that the intensity of pain in patients with chronic back pain is encoded in the anterior insular cortex, the frontal operculum, and the pons; the change of pain in chronic back pain and chronic migraine patients is mainly encoded in the anterior insular cortex. At the individual level, we identified a more complex picture where each patient exhibited their own signature of endogenous pain encoding. The diversity of the individual cortical signatures of chronic pain encoding results bridge between clinical observations and neuroimaging; they add to the understanding of chronic pain as a complex and multifaceted disease.

Age- and frequency-dependent changes in dynamic contrast perception in visual snow syndrome.

OBJECTIVE: Patients with visual snow syndrome (VSS) suffer from a debilitating continuous ("TV noise-like") visual disturbance. They report problems with vision at night and palinopsia despite normal visual acuity. The underlying pathophysiology of VSS is largely unknown. Currently, it is a clinical diagnosis based on the patient's history, an objective test is not available. Here, we tested the hypothesis that patients with VSS have an increased threshold for detecting visual contrasts at particular temporal frequencies by measuring dynamic contrast detection-thresholds. METHODS: Twenty patients with VSS were compared to age-, gender-, migraine- and aura-matched controls in this case-control study. Subjects were shown bars randomly tilted to the left or right, flickering at six different frequencies (15 Hz, 20 Hz, 25 Hz, 30 Hz, 35 Hz, 40 Hz). The contrast threshold (CT) for detection of left or right tilt was measured in a two-alternative adaptive forced-choice procedure (QUEST). The threshold was defined as the Michelson contrast necessary to achieve the correct response in 75% of the cases. RESULTS: The CT increased for higher flicker frequencies (ANOVA: main effect frequency: F (5,180) = 942; p < 0.001), with an additional significant frequency*diagnosis interaction (ANOVA: F (5,180) = 5.00; p < 0.001). This interaction effect was due to an increased CT at a flicker frequency of 15 Hz in the VSS cohort (VSS: MC = 1.17%; controls: MC = 0.77%). At the other frequencies, group comparisons revealed no differences. Furthermore, in the VSS cohort we observed an increase of CT with higher age (r = 0.69; p < 0.001), which was not seen in controls (r = 0.30; p = 0.20). CONCLUSIONS: This study demonstrates a lower visual contrast sensitivity exclusively at 15 Hz in VSS patients and demonstrates frequency-dependent differences in dynamic contrast vision. The peak sensitivities of both parvo- and magnocellular visual pathways are close to a frequency of about 10 Hz. Therefore, this frequency seems to be of crucial importance in everyday life. Thus, it seems plausible that the impairment of contrast sensitivity at 15 Hz might be an important pathophysiological correlate of VSS. Furthermore, the overall age-related decrease in contrast sensitivity only in VSS patients underscores the vulnerability of dynamic contrast detection in VSS patients. Dynamic CT detection seems to be a promising neurophysiological test that may contribute to the diagnosis of VSS.

Visual Phenomena Associated With Migraine and Their Differential Diagnosis.

BACKGROUND: Visual phenomena are of many different kinds; their differential diagnosis is usually possible with directed history-taking. In this review, we describe common visual phenomena that must be distinguished from a migraine aura. METHODS: This review is based on publications retrieved by a selective search in PubMed and the Web of Knowledge/Science, with special attention to the current classification of the International Headache Society and the recommendations of the German Migraine and Headache Society. The following search terms were used: "visual phenomena/phenomenon," "migraine aura," and "persistent/complication/ long-lasting/ongoing." RESULTS: The most helpful questions for differential diagnosis are whether the symptoms are present in one eye only or in both, whether their onset was sudden or over minutes or days, and whether the phenomenon has occurred only once or repeatedly, or is persistently present. A visual aura associated with migraine must be distinguished, in rare cases, from an isolated epileptic aura, from cerebral/retinal ischemia, or from visual snow. Further differential diagnoses include a persisting perceptual disturbance after hallucinogen use (HPPD, "hallucinogen persisting perception disorder") and the Charles Bonnet syndrome (CBS); the latter arises as a consequence of severely impaired vision. Posterior reversible encephalopathy syndrome (PRES) is rare and generally reveals itself over its further course through the appearance of additional clinical manifestations. Primary ophthalmological causes can usually be readily identified and classified by ophthalmological examination. CONCLUSION: Patients with visual phenomena typically consult physicians from various medical specialties. A correct differential diagnosis can be made based on the history if the physician views the symptoms in their overall context to determine the particular disease entity that is responsible.

tVNS in the management of headache and pain.

First clinical observations of the therapeutic effect of vagus nerve stimulation were of patients who were treated for refractory epilepsy with a fully implanted vagus nerve stimulator, who also reported an improvement of their migraine and cluster headache. With the development of non-invasive vagus nerve stimulation, first clinical studies concerning a possible therapeutic effect in migraine and cluster headache were performed. In a controlled study, transcutaneous cervical vagus nerve stimulation (tcVNS) showed a significant but limited effect in acute treatment of a migraine attack. There was no significant prophylactic effect in episodic migraine. Concerning cluster headache, there was a clear beneficial effect in the prophylaxis of chronic cluster headache and in the attack treatment in episodic cluster headache. There are fewer studies in the literature on the effect of transcutaneous auricular vagus nerve stimulation (taVNS), with a partial overlap with studies on electrical ear acupuncture. In a small controlled clinical trial, there was a significant effect of taVNS in the prevention of chronic migraine. In less defined clinical studies, there were some positive signs that the method may be beneficial in chronic back pain and in unspecific gastro-intestinal pain in adolescents. Based on the available evidence, it is probable that vagus nerve stimulation can have a clinically meaningful influence on pain syndromes, but there are still several questions (e.g. frequency of the stimulation; duration of the stimulation; differential effects of auricular vagus stimulation and cervical vagus stimulation) to answer before vagus stimulation can be used widely in the clinic.

Localised increase in regional cerebral perfusion in patients with visual snow syndrome: a pseudo-continuous arterial spin labelling study.

OBJECTIVES: We aimed to investigate changes in regional cerebral blood flow (rCBF) using arterial spin labelling (ASL) in patients with visual snow syndrome (VSS), in order to understand more about the underlying neurobiology of the condition, which remains mostly unknown. METHODS: We performed an MRI study in which whole-brain maps of rCBF were obtained using pseudo-continuous ASL. Twenty-four patients with VSS and an equal number of gender and age-matched healthy volunteers took part in the study. All subjects were examined with both a visual paradigm consisting of a visual-snow like stimulus, simulating key features of the snow, and a blank screen at rest, randomly presented. RESULTS: Patients with VSS had higher rCBF than controls over an extensive brain network, including the bilateral cuneus, precuneus, supplementary motor cortex, premotor cortex and posterior cingulate cortex, as well as the left primary auditory cortex, fusiform gyrus and cerebellum. These areas were largely analogous comparing patients either at rest, or when looking at a 'snow-like' visual stimulus. This widespread, similar pattern of perfusion differences in either condition suggests a neurophysiological signature of visual snow. Furthermore, right insula rCBF was increased in VSS subjects compared with controls during visual stimulation, reflecting a greater task-related change and suggesting a difference in interoceptive processing with constant perception of altered visual input. CONCLUSION: The data suggest VSS patients have marked differences in brain processing of visual stimuli, validating its neurobiological basis.