Scabies-induced lichen simplex chronicus misdiagnosed as psychogenic pruritus: a case report.

Introduction: Lichen simplex chronicus has been defined as a localized skin condition characterized by thickening, hyperpigmentation and accentuated skin markings from chronic itching and from repeated scratching. The affected skin area is usually described as demarcated, and often circumscribed. It has even been defined as a "psychogenic pruritic disorder".

Gender differences in cerebral metabolism for color processing in mice: A PET/MRI Study.

Introduction: Color processing is a central component of mammalian vision. Gender-related differences of color processing revealed by non-invasive functional transcranial Doppler ultrasound suggested right hemisphere pattern for blue/yellow chromatic opponency by men, and a left hemisphere pattern by women.

Materials And Methods: The present study measured the accumulation of [18F]fluorodeoxyglucose ([18F]FDG) in mouse brain using small animal positron emission tomography and magnetic resonance imaging (PET/MRI) with statistical parametric mapping (SPM) during light stimulation with blue and yellow filters compared to darkness condition.

Gender-related differences in physiologic color space: a functional transcranial Doppler (fTCD) study.

Simultaneous color contrast and color constancy are memory processes associated with color vision, however, the gender-related differences of 'physiologic color space' remains unknown. Color processing was studied in 16 (8 men and 8 women) right-handed healthy subjects using functional transcranial Doppler (fTCD) technique. Mean flow velocity (MFV) was recorded in both right (RMCA) and left (LMCA) middle cerebral arteries in dark and white light conditions, and during color (blue and yellow) stimulations.

Gender-related asymmetric brain vasomotor response to color stimulation: a functional transcranial Doppler spectroscopy study.

Background And Purpose: The present study was designed to examine the effects of color stimulation on cerebral blood mean flow velocity (MFV) in men and women.

Methods: The study included 16 (8 men and 8 women) right-handed healthy subjects. The MFV was recorded simultaneously in both right and left middle cerebral arteries in Dark and white Light conditions, and during color (Blue, Yellow and Red) stimulations, and was analyzed using functional transcranial Doppler spectroscopy (fTCDS) technique.

High-frequency ultrasound imaging of the duodenum and colon in patients with symptomatic giardiasis in comparison to amebiasis and healthy subjects.

Aim: The application of ultrasound may be suitable for evaluating the effects of intestinal cytoskeletal rearrangement of the duodenum and colon as a result of exposure to live Giardia lamblia trophozoites. We studied the sonographic appearance of the duodenum and colon in giardiasis compared with amebiasis and healthy subjects.

Methods: Sonographic images obtained from 100 consecutive patients with symptomatic giardiasis were compared to those taken from 40 patients with amebiasis and 40 healthy subjects.

Cerebral lateralisation for facial processing: gender-related cognitive styles determined using Fourier analysis of mean cerebral blood flow velocity in the middle cerebral arteries.

Facial processing was studied in 16 (eight men and eight women) right-handed healthy participants using a new functional transcranial Doppler technique called functional transcranial Doppler spectroscopy (fTCDS). MFV was recorded simultaneously in both right and left middle cerebral arteries in dark condition and during visual processing of object and facial tasks. fTCDS used Fourier analysis of mean flow velocity (MFV) time series to derive spectral density estimates that correlate with expected mental activity.

Cerebral lateralization and general intelligence: gender differences in a transcranial Doppler study.

The present study evaluated cerebral lateralization during Raven's progressive matrices (RPM) paradigm in female and male subjects. Bilateral simultaneous transcranial Doppler (TCD) ultrasound was used to measure mean blood flow velocities (MBFV) in the right and left middle cerebral arteries (MCAs) in 24 (15 females and 9 males) right-handed normal subjects. The female subjects used a left hemisphere strategy, while males used a right hemisphere strategy to successfully solve RPM tasks.

Asymmetry in cerebral blood flow velocity with processing of facial images during head-down rest.

Introduction: Ability to interpret facial expression is crucial for non-verbal communication among humans, and could be affected by changes in cerebral circulation during exposure to microgravity or its simulation.

Methods: There were 16 subjects (8 men and 8 women) who were exposed to 24 h of -6 degrees head-down rest (HDR). Transcranial Doppler ultrasonography was used to monitor mean blood flow velocity (MBFV) in the middle cerebral arteries bilaterally during processing of facial images before, at 6 and 24 h of HDR, and after HDR (Pre-, 6H-, 24H-, and Post-HDR, respectively).

Cerebral lateralization for motor tasks in simulated microgravity a transcranial Doppler technique for astronauts.

In Space, central cognitive operations are unaffected but humans are slower in perceptual-motor performance. Transcranial Doppler ultrasonography was used to monitor blood flow velocity in both middle cerebral arteries during unilateral and bilateral fingers' movements before, during and after -6 degrees 24 hours of head-down tilt (HDT) in 14 (8 males and 6 females) subjects. Physiologic hemisphere dominance was assessed by breath-holding test.

Application of risk analysis and geographic information system technologies to the prevention of diarrheal diseases in Nigeria.

Among the poor in developing countries, up to 20% of an infant's life experience may include diarrhea. This problem is spatially related to the lack of potable water at different sites. This project used risk analysis (RA) methods and geographic information system (GIS) technologies to evaluate the health impact of water source.

Cerebral lateralization in random letter task in the visual modality: a transcranial Doppler study.

Seven right handed volunteers were studied to determine cerebral lateralization patterns for a visually presented random letter task. The subjects participated in three conditions, which included resting baseline, passive fixation (nonlinguistic), and random letter (linguistic) tasks. Mean blood flow velocity (MBFV) was recorded using bilateral simultaneous transcranial Doppler measurements in the posterior cerebral arteries in these conditions.

Cerebrovascular dysautoregulation syndrome complex--brain hypoperfusion precedes hypotension and cardiac asystole.

A 43-year-old male with history of recurrent episodes of syncope, non-sustained wide complex tachycardia and structurally normal heart was studied. Syncope was induced with upright tilt provocation, while monitoring cerebral blood flow velocity with Doppler ultrasound, concurrently with invasive blood pressure, heart rate and rhythm determination. Postural induced cerebral hypoperfusion preceded hypotension and cardiac asystole.

Perfusion of the visual cortex during pressure breathing at different high-G stress profiles.

The effects of pressure breathing for G protection (PBG) on perfusion of the visual cortex were studied in a subject during various high-G stress profiles. Blood flow velocity was measured in the posterior cerebral artery using a transcranial Doppler (TCD) ultrasound instrument. The G profiles examined included gradual and rapid onset rates.

Isoproterenol induced cerebral hypoperfusion in a heart transplant recipient.

To determine the effect of tilt isoproterenol provocation on cerebral perfusion in a patient with denervated heart, transcranial Doppler sonography was used to assess changes in cerebral blood flow velocity during upright tilt test. A 51-year-old man with history of syncopal spells after heart transplantation was evaluated by using upright tilt test with and without isoproterenol for 30 minutes, respectively, at 80 degrees inclined. Mean cerebral blood flow was measured in the main stem of the right middle cerebral artery.

Critical limits of pressure-flow relation in the human brain.

Background: This study was designed to determine the minimal mean flow velocity and pressure-flow relation necessary to preserve human consciousness.

Methods: Passive upright tilt provocation was used in conjunction with transcranial Doppler in 80 patients with a history of syncope of unknown etiology. Cerebral blood flow velocity, blood pressure, and heart rate were monitored noninvasively.

Cerebral lateralization and color perception: a transcranial Doppler study.

Eight normal subjects were examined in dark, light and color conditions. Mean cerebral blood flow velocity (MBFV) were recorded almost simultaneously from their posterior cerebral arteries (PCA) using transcranial Doppler (TCD) ultrasound. The side-to-side difference was significant during the dark (p = 0.

Cerebral lateralization in linguistic and nonlinguistic perception: analysis of cognitive styles in the auditory modality.

Twenty-two normal subjects (9 left-handers, 13 right-handers) and five dyslexic patients (3 right-handers, and 2 left-handers) were characterized by physiologic hemisphere dominance. The latter was determined by the response of the middle cerebral artery (MCA) blood flow velocity, measured using the transcranial Doppler (TCD) technique, to hypoventilation (hypercapnia). Using bilateral almost simultaneous TCD measurements of mean blood flow velocity in the MCA, lateralization was determined in response to linguistic and nonlinguistic paradigms.

Fourier analysis of the cerebrovascular system.

We performed Fourier analysis of the middle cerebral artery blood flow velocity waveform envelope in 14 normal subjects (group A) and 15 patients, of whom five had arteriovenous malformations (group B), five had cerebral vasospasm (group C), and five had arterial hypertension (group D). Measurements were obtained under conditions of normocapnia, hypercapnia, and hypocapnia. The Fourier coefficients measured in the first five harmonics of the Doppler waveforms of group A were used as the reference baseline and were compared with the coefficients found in the other three groups.

Transcranial Doppler evaluation of syncope: an application in aerospace physiology.

A non-invasive method which combines the simultaneous measurement of mean arterial blood pressure (MBP), heart rate (HR) and mean cerebral blood flow velocity (MFV) was used to monitor patients with history of syncope, in horizontal and vertical posture tilt at 80 degrees. MFV in the right middle cerebral artery was measured using a transcranial Doppler instrument (TCD). MFV decreased concurrently with the onset of symptoms, and at the time of syncope reached an average of 68% below pre-tilt values.