Monitoring of human tissue hemodynamics is invaluable in clinics as the proper blood flow regulates cellular-level metabolism. Time-domain diffuse correlation spectroscopy (TD-DCS) enables noninvasive blood flow measurements by analyzing temporal intensity fluctuations of the scattered light. With time-of-flight (TOF) resolution, TD-DCS should decompose the blood flow at different sample depths. For example, in the human head, it allows us to distinguish blood flows in the scalp, skull, or cortex. However, the tissues are typically polydisperse. So photons with a similar TOF can be scattered from structures that move at different speeds. Here, we introduce a novel approach that takes this problem into account and allows us to quantify the TOF-resolved blood flow of human tissue accurately. We apply this approach to monitor the blood flow index in the human forearm in vivo during the cuff occlusion challenge. We detect depth-dependent reactive hyperemia. Finally, we applied a controllable pressure to the human forehead in vivo to demonstrate that our approach can separate superficial from the deep blood flow. Our results can be beneficial for neuroimaging sensing applications that require short interoptode separation.

Visual stimulation is one of the most commonly used paradigms for cerebral cortex function investigation. Experiments typically involve presenting to a volunteer a black-and-white checkerboard with contrast-reversing at a frequency of 4 to 16 Hz. The aim of the present study was to investigate the influence of the flickering frequency on the amplitude of changes in the concentration of oxygenated and deoxygenated hemoglobin. The hemoglobin concentrations were assessed with the use of a high resolution diffuse optical tomography method. Spatial distributions of changes in hemoglobin concentrations overlaying the visual cortex are shown for various stimuli frequencies. Moreover, the hemoglobin concentration changes obtained for different source-detector separations (from 1.5 to 5.4 cm) are presented. Our results demonstrate that the flickering frequency had a statistically significant effect on the induced oxyhemoglobin changes (p < 0,001). The amplitude of oxy hemoglobin concentration changes at a frequency of 8 Hz was higher in comparison with that measured at 4 Hz :[median(25th-75thpercentiles) 1.24

It is estimated that around 15 million people survived polio infection worldwide since early twentieth century. In 1950 effective vaccination was used for first time. Since that time number of affected people decreased. The last epidemic of Haine-Medine disease in Poland was in 1950s. Another rare cases of infections were observed till 1970s. About at least 15 years after polio virus infection, slowly progressive muscle limbs paresis with muscle atrophy, joints pain, paresthesia were observed in polio survivors. That constellation of symptoms was called post-polio syndrome (PPS). PPS frequency among people after paralytic and nonparalytic polio infectious is ranged from 30% to 80%. Fatigue that leads to physical and mental activity deterioration is another important symptom that is observed in 90% of patients with PPS. Etiology of disease remains elusive. Probably it is an effect of spine frontal horns motoneurons damage during acute virus polio infection that leads to overloading and degeneration of remaining ones. The most important risk factors of PPS are female sex and respiratory symptoms during acute polio infection. Electromyography is an important part of PPS diagnostic process. Electrophysiological abnormalities are seen in clinically affected and unaffected muscles. The most frequent are fasciculations and fibrillations during rest activity, extension of motor unit area, time duration and amplitude. In this study we described three cases of people who developed PPS years after Haine-Medine disease and correlation between their EMG results and clinical status. We also analyzed electromyography results both after one month since first PPS signs occurred as well as after few years. Presentation of dynamic changes in EMG was the most important aim of that study.

Usually limbic encephalitis (LE) is a paraneoplastic neurologic syndrome. LE symptoms can precede cancer even by a few years. Almost 50% of LE cases are connected with small cell lung carcinoma. Testis and breast cancers, granulomatous disease, thymoma, and teratomas are also often connected with LE. Other cases have infectious and autoimmunological aetiology. In LE limbic system dysfunction is observed, and it is accompanied by cerebellum and brain stem abnormalities as well as polyneuropathy. Paraneoplastic limbic encephalitis is sometimes a part of larger syndrome in which brain stem and spinal cord are involved in an inflammatory process called paraneoplastic encephalomyelitis. The main LE symptoms are: impairment of cognitive functions with subacute beginning, partial and generalised seizures, mental distress, disturbances of consciousness, and limb paresis. In MRI study hyperintensive lesions in the medial part of the temporal lobes in T2 and FLAIR sequences are present. Sharp and slow waves in electroencephalography in the temporal area are also frequent. In cerebrospinal fluid pleocytosis, elevation of protein level, intensification of immunoglobulin synthesis, and oligoclonal bands can be detected. The majority of patients with paraneoplastic LE have onconeural antibodies in the blood. The presented study is a description of the clinical course of the disease in four patients diagnosed with LE.

The course of brain stroke in the Polish population is more severe in patients over 85 years old than in younger ones. The key risk factor in this group is atrial fibrillation.

Interferometric near-infrared spectroscopy (iNIRS) is an optical method that noninvasively measures the optical and dynamic properties of the human brain in vivo. However, the original iNIRS technique uses single-mode fibers for light collection, which reduces the detected light throughput. The reduced light throughput is compensated by the relatively long measurement or integration times (∼1 sec), which preclude monitoring of rapid blood flow changes that could be linked to neural activation. Here, we propose parallel interferometric near-infrared spectroscopy (πNIRS) to overcome this limitation. In πNIRS we use multi-mode fibers for light collection and a high-speed, two-dimensional camera for light detection. Each camera pixel acts effectively as a single iNIRS channel. So, the processed signals from each pixel are spatially averaged to reduce the overall integration time. Moreover, interferometric detection provides us with the unique capability of accessing complex information (amplitude and phase) about the light remitted from the sample, which with more than 8000 parallel channels, enabled us to sense the cerebral blood flow with only a 10 msec integration time (∼100x faster than conventional iNIRS). In this report, we have described the theoretical foundations and possible ways to implement πNIRS. Then, we developed a prototype continuous wave (CW) πNIRS system and validated it in liquid phantoms. We used our CW πNIRS to monitor the pulsatile blood flow in a human forearm in vivo. Finally, we demonstrated that CW πNIRS could monitor activation of the prefrontal cortex by recording the change in blood flow in the forehead of the subject while he was reading an unknown text.

AbstractBrain stroke connected with aortic blood flow disturbances is a rare disease and its incidence is difficult to assume. Nevertheless, 10-50% of patients with aortic dissection may not experience any pain. In case of 18-30% patients with aortic dissection neurological signs are first disease presentation and among them ischemic stroke is the most common. The most popular aortic dissection classification is with use of Stanford system. Type A involves the ascending aorta and type B is occurring distal to the subclavian artery. Aortic dissection risk factors include hypertension, cystic medionecrosis, bicuspid aortic valve and Marfan’s or Ehlers-Danlos syndrome.

The key risk factor in this group is the atrial fibrillation. The elderly patients require an intensive monitoring of the health condition by reference to brain stroke risk factors, especially atrial fibrillation.