Assessment of neural alterations in obstructive sleep apnoea syndrome: can apparent diffusion coefficient measurements be useful?

BACKGROUND AND AIMS: Our aim was to investigate whether neurological alteration in patients with obstructive sleep apnoea syndrome (OSAS) with apparently normal cerebral and cerebellar structures can be assessed by means of apparent diffusion coefficient (ADC) measurement and to investigate the association between OSAS severity and ADC values. METHODS: Following the acquisition of diffusion-weighted cranial magnetic resonance imaging, ADC measurements were performed in 24 different apparently normal cerebral and cerebellar structures, including the bilateral frontal and parietal cortices, insulae, cingulate gyri, hippocampi, frontal and parieto-occipital periventricular white matter (PWM), caudate nuclei, putamen, thalami, cerebellar hemispheres, pons and mesencephalon in 47 OSAS patients and 20 control subjects. The ADC values of the patients and the control group were compared. The association between the apnoea-hypopnoea index (AHI) and the ADC values of the patients were investigated. RESULTS: The ADC values in the bilateral frontal PWM were lower in the patient group than those in the control subjects (P < 0.05). The measurements in the right cingulate gyri of the OSAS patients exhibited significantly higher ADC values than those of the control group (P = 0.002). Bilateral thalamic ADC values in severe OSAS patients were significantly higher than those in mild and moderate OSAS patients (P < 0.05). CONCLUSION: The ADC measurement is a simple and effective technique to evaluate neural alteration of the brain in patients with OSAS. ADC measurements can also be useful in the evaluation of the association between the AHI and the degree of neural alteration in the central nervous system.

Stereological and Morphometric Analysis of MRI Chiari Malformation Type-1.

OBJECTIVE: In this study, we aimed to investigate the underlying ethiological factors in chiari malformation (CM) type-I (CMI) via performing volumetric and morphometric length-angle measurements. METHODS: A total of 66 individuals [33 patients (20-65 years) with CMI and 33 control subjects] were included in this study. In sagittal MR images, tonsillar herniation length and concurrent anomalies were evaluated. Supratentorial, infratentorial, and total intracranial volumes were measured using Cavalieri method. Various cranial distances and angles were used to evaluate the platybasia and posterior cranial fossa (PCF) development. RESULTS: Tonsillar herniation length was measured 9.09±3.39 mm below foramen magnum in CM group. Tonsillar herniation/concurrent syringomyelia, concavity/defect of clivus, herniation of bulbus and fourth ventricle, basilar invagination and craniovertebral junction abnormality rates were 30.3, 27, 18, 2, 3, and 3 percent, respectively. Absence of cisterna magna was encountered in 87.9% of the patients. Total, IT and ST volumes and distance between Chamberlain line and tip of dens axis, Klaus index, clivus length, distance between internal occipital protuberance and opisthion were significantly decreased in patient group. Also in patient group, it was found that Welcher basal angle/Boogard angle increased and tentorial slope angle decreased. CONCLUSION: Mean cranial volume and length-angle measurement values significantly decreased and there was a congenital abnormality association in nearly 81.5 percent of the CM cases. As a result, it was concluded that CM ethiology can be attributed to multifactorial causes. Moreover, congenital defects can also give rise to this condition.

Pneumocephalus and pneumorrhachis after spinal surgery: case report and review of the literature.

Trauma is a common cause of pneumocephalus, or air in the cranial cavity, and of pneumorrhachis, or the presence of intraspinal air. After spinal surgery, occurrence of pneumocephalus, especially with pneumorrhachis, is extremely rare. We report the case of a patient who developed pneumocephalus and pneumorrhachis after lumbar disc surgery and pedicle screw fixation. There was no cerebrospinal fluid leakage during surgery. On postoperative day 1, the patient complained of headache, nausea, and dizziness. Brain and lumbar computed tomography scans revealed pneumocephalus and pneumorrhachis. With conservative treatment, the patient's complaints resolved within 10 days.

Association of Chiari I malformation and cerebellar ectopia with sensorineural hearing loss.

We aimed to examine the prevalence of cerebellar tonsil ectopia and Chiari 1 malformation in sensorineural hearing loss (SHL) that has, to the best of our knowledge, not been studied previously. Magnetic resonance imaging records of 166 subjects with SHL and 50 controls without known otologic disturbances were included in the study. A tonsils descent more than 2 mm was assumed as cerebellar ectopia, and a descent equal to or more than 5 mm was assumed as Chiari 1 malformation. A tonsil descent group was also formed by summation of both groups. Transverse diameters of bilateral intracranial vertebral arteries and transverse sinuses were also measured, and all parameters were analyzed using appropriate statistics. A significant difference of frequencies of Chiari 1, ectopia, and tonsil descent was detected between patients and controls. In comparison of cerebellar ectopia and Chiari 1 groups, SHL did not show any significant difference. The left lateral sinus diameter showed positive correlation with tonsil descent. There was no significant correlation for the diameters of other vessels. A powerful correlation was detected between SHL and age. In addition, right and vertebral artery diameters showed positive correlations with age. Chiari 1 malformation and cerebellar ectopia showed an association with SHL. These patients should also be evaluated for otologic disturbances. Further high-resolution magnetic resonance imaging studies to explain the exact cause of this currently unknown association seems required.

Association of the polymorphisms of vitamin D receptor and aggrecan genes with degenerative disc disease.

The aim of this study was to investigate the association between the polymorphisms of the vitamin D receptor (VDR) and aggrecan genes and degenerative disc disease in young Turkish patients. Aggrecan and VDR proteins are the main components of bone and cartilage. In our study, the polymorphisms of the VDR and aggrecan genes were investigated in a total of 300 individuals regarding disc degeneration and herniation. An association was found in the patients having VDR gene TT, Tt, FF, and Ff genotypes with the protrusion type of disc herniation, whereas the patients having tt and ff genotypes were associated with extrusion/sequestration types of the disease. Also, an association was observed between TT and FF genotypes of the VDR gene and mild forms of disc degeneration; and tt, ff, and Ff genotypes and severe forms of the disease. There was also an association between shorter, normal, and longer alleles of the aggrecan gene and a protrusion type of disc herniation. An association was found between short alleles and multilevel and severe disc degeneration, as well as normal and long alleles and mild disc degeneration. This study revealed that the polymorphisms of the VDR and aggrecan genes are associated with disc degeneration and herniation.

Evaluation of mental foramina in adult living crania with MDCT.

PURPOSE: Multi-detector Computed Tomography (MDCT) is an exquisite technique in demonstrating the cranial foramina. This study aimed to assess the anatomic variations and locations of mental foramina in living adult mandible by MDCT. METHODS: MDCT data of 100 dentulous adult subjects were collected from the high-resolution examinations that covered the mandible. Presence and number of foramina, their diameter and distance from the mid line that is mid sagittal plane and alveolar ridge were recorded. RESULTS: Mental foramina was clearly identified, localized and characterized in all subjects. Duplication was observed in four patients. Among them, one subject had bilateral accessory foramina. Mid line distances were significantly higher in men than women. Distances and diameters of right foramina were insignificantly higher in the males. Also, left foramina was insignificantly wider in women. Positive correlations were noticed between the measurements of right and left foramina. CONCLUSIONS: This is the first study on mental foramina in living mandible with MDCT. With its tremendous capabilities, MDCT may be established in anatomical studies and preoperative planning.

Prenatal diagnosis of a fetal intracranial immature teratoma.

Congenital intracranial teratoma is a rare disease. A fetus with a congenital intracranial teratoma presenting with a hydrocephalus at 27 weeks' gestation is presented. Prenatal ultrasonography and fetal magnetic resonance imaging demonstrated a huge, heterogeneous intracranial mass including the infra- and supratentorial region and polyhydramnios. At 28 weeks' gestation, a cesarean section was performed to avoid divisive operation during delivery. The infant died after 10 min from respiratory failure. Histological examination revealed the diagnosis of immature teratoma. Early detection of congenital intracranial tumors is crucial. The prognosis is poor with death usually occurring shortly after birth.

Variations of supraorbital foramina in living subjects evaluated with multidetector computed tomography.

BACKGROUND: We aimed to evaluate the anatomic variations of supraorbital foramina/notches in living subjects using multidetector CT (MDCT) related to age, sex, and side. METHODS: Computer records of 399 patients (207 men and 192 women) referred for high-resolution CT examinations were evaluated for presence, shape, width, and distance from the nasion. RESULTS: The most common presentation was single notch. Presence of double foramen/notch was higher in the right. Bilateral notches were wider in men. Bilateral foramina and left notches were located more lateral in men. Notches were closer to nasion than foramina. Positive correlations were found between right and left sides for the diameters and distances to nasion. Widths of foramina showed negative correlation with the distances to nasion. CONCLUSIONS: This is the first study showing supraorbital foramen/notch variations in living crania. MDCT should be established in anatomical studies and may be used in preoperative evaluation.

Polycystic ovary syndrome is related to idiopathic intracranial hypertension according to magnetic resonance imaging and magnetic resonance venography.

Magnetic resonance imaging and magnetic resonance venography findings of 30 women with polycystic ovary syndrome and headache were studied prospectively. Our magnetic resonance imaging and magnetic resonance venography findings support that polycystic ovary syndrome with severe headache is a promoter of idiopathic intracranial hypertension.

The effects of levodopa use on diffusion coefficients in various brain regions in Parkinson's disease.

We aimed to evaluate the effects of l-dopa use on apparent diffusion coefficient (ADC) values of different brain regions in Parkinson's disease (PD) patients. Thirty-five subjects underwent magnetic resonance imaging (MRI), including 21 PD patients (13 men, 8 women; mean age, 63 years+/-8), and 14 sex and age-matched control subjects. PD patients were separated into two groups according to the duration of l-dopa usage: patients using l-dopa less and more than 1 year. According to the disease duration two other groups were formed: patients diagnosed less and more than 1 year. Unified Parkinson Disease Rating Scale (UPDRS) scores of PD patients were detected. Diffusion weighted images (DWI) and ADC maps of patients and controls were evaluated and regional ADC (rADC) measurements were performed. Patients' age was not significantly different between groups. UPDRS was significantly different between the patient groups. There was no significant difference of rADC values between PD and control groups, and within the different PD groups. Short- and long-term l-dopa usage in PD patients did not cause any change rADC values in various brain regions.

Hemodynamic changes in the cephalic vein of patients with hemodialysis arteriovenous fistula.

PURPOSE: To assess via Doppler sonography the hemodynamic changes in the cephalic vein after creation of an arteriovenous fistula, and to compare radiocephalic and brachiocephalic fistulas. METHODS: Thirty-three hemodialysis patients and 54 controls were enrolled in the study. The cephalic vein was examined with a 7.5-MHz linear-array transducer. Doppler waveform parameters (resistance index, pulsatility index), time-averaged maximum flow velocity (TAV), peak systolic velocity (PSV), end-diastolic velocity (EDV), and the cross-sectional area of the vessel (A) were measured. Cephalic vein flow volume (CVFV) was calculated as TAV x A. RESULTS: CVFV, PSV, EDV, A, RI, and PI were 45.5, 7.2, 6.7, 7.7, 1.2, and 1.32 times higher, respectively, in the cephalic vein of hemodialysis patients compared with controls. Both CVFV and A were higher in brachiocephalic patients compared with radiocephalic patients (1,983 +/- 1,199 versus 870 +/- 322 ml/min [p < 0.05] and 50.3 +/- 38.9 versus 21.0 +/- 7.8 mm(2) [p < 0.05], respectively). CONCLUSION: The increase in cross-sectional area and flow volume of the cephalic vein is larger in patients with brachiocephalic fistulas than in those with radiocephalic fistulas; however, flow velocities and waveform parameters are not different.

Large cystic infiltrating ductal carcinoma in male breast.

Cystic infiltrating ductal carcinoma is a very rare entity that, to the best of our knowledge, has not yet been reported in males. We report the sonographic and CT findings of a large cystic infiltrating ductal carcinoma in a 51-year-old man. Cystic infiltrating ductal carcinoma is a very rare entity that, to the best of our knowledge, has not yet been reported in males. We report the sonographic and CT findings of a large cystic infiltrating ductal carcinoma in a 51-year-old man.

Cerebral and cerebellar ADC values during a migraine attack.

INTRODUCTION: We investigated the diffusion-weighted MRI changes, apparent diffusion coefficient (ADC) values, and conventional MRI findings in specific brain areas during migraine attacks in patients with and without aura. METHODS: Included in the study were 22 patients (2 male, 20 female) aged between 17 and 49 years who were diagnosed as having migraine according to the diagnostic criteria of the International Headache Society. Also included in the study were 18 age- and sex-matched healthy volunteers. Hyperintense lesions were evaluated in conventional MR images. Heavily diffusion-weighted images, ADC maps, and segmented ADC maps generated for regional ADC (rADC) measurements, were also studied. ADC values from specific brain areas were used with appropriate region of interests (ROI). RESULTS: Migraine with aura was diagnosed in 13 patients and migraine without aura was diagnosed in 9 patients. A total of 23 hyperintense lesions within the periventricular white matter and deep white matter were detected in five patients (21.8%). All of these hyperintense lesions were seen in migraine patients with aura. In only one patient did a hyperintense lesion show an increased diffusion pattern on diffusion-weighted images and ADC maps. One hyperintense lesion was detected in the control group (5.5%). There was no significant difference in ADC values between the migraine and control groups. CONCLUSION: T2-weighted hyperintense lesions were significantly more frequent in migraine patients especially in those with aura than in the control group. No diffusion alterations in diffusion-weighted images were detected in the infra- and supratentorial brain areas during migraine attacks in patients with and without aura.

Doppler sonography evaluation of flow velocity and volume of the extracranial internal carotid and vertebral arteries in healthy adults.

PURPOSE: To measure with Doppler sonography the velocity and volume of blood flow in the extracranial internal carotid artery (ICA) and vertebral artery (VA) of healthy adults and to calculate total cerebral blood flow volume (tCBFV). METHODS: Bilateral ICA and VA were examined sonographically in 180 healthy adults. Angle-corrected peak systolic (Vps), end-diastolic (Ved), and time-averaged maximum blood flow velocity (TAV) were measured in pulsed Doppler mode, and the resistance index (RI) and pulsatility index (PI) were calculated. The cross-sectional area (A) was measured on gray-scale images. Volume flow was calculated as FV = TAV x A, and tCBFV was calculated as the sum of the right and left ICA and VA volume flow. RESULTS: tCBFV was 651 +/- 96 ml/min for the entire population. There was a significant decrease in Vps, Ved, TAV, and tCBFV with age in all arteries. RI and PI values initially declined and then increased with age. Cross-sectional area increased with age in ICA but not in VA. PI and RI were higher in men than in women. Blood flow velocity and volume were higher, and RI was lower in the left than in the right VA. CONCLUSION: The Doppler sonographic assessment of extracranial ICA and VA blood flow volume may be useful for the study of cerebral hemodynamic changes in patients with cerebrovascular disorders. Age-dependent changes should be considered, for instance, in the management of intensive care patients with impaired cerebral perfusion.

Acute effect of smoking on gallbladder emptying and refilling in chronic smokers and nonsmokers: a sonographic study.

AIM: To ultrasonographically evaluate the acute effects of smoking on gallbladder contraction and refilling in chronic smokers and nonsmokers. METHODS: Fifteen chronic smokers (21-30 years old) and fifteen nonsmokers (21-35 years old) participated in this study. Chronic smokers were selected among the volunteers who had been smoking for at least 5 years and 10 cigarettes per day (mean 17.5/d). Examinations were performed in two separate days. In the first day, basal gallbladder (GB) volumes of volunteers were measured after 8-h fasting. After the examinations, participants had a meal containing at least 30-40 gram fat. Gallbladder volume was assessed at 5, 15, 30, 60, 120 and 180 min after the meal. In the second day, participants smoked 2 cigarettes after 8-h fasting. Then, they had the same meal, and gallbladder measurements were repeated at the same time points. Same procedures were applied to both groups. RESULTS: The mean starving GB volumes were 23.3 +/- 3.3 mL in the first day, 21.9 +/- 3.0 mL in the second day in nonsmoker group and 18.3 +/- 3.0 mL in the first day, 19.5 +/- 2.8 mL in second day in smoker group. There was no significant difference between starving GB volumes. We did not find any significant difference between the GB volumes measured at 5, 15, 30, 60, 120 and 180 min in the first and second days in nonsmoker group. In smokers, post cigarette GB volume was found significantly higher at 5, 15 and 30 min which corresponded to GB contraction phase (P < 0.05). Control GB volume measurements were not significantly different between the two groups. Post-smoking GB volumes were also not significantly different between the two groups. CONCLUSION: Smoking prolongs the maximal GB emptying time both in smokers and in nonsmokers though it is not significant. It delays GB contraction in chronic smokers and causes a significant decrease in GB emptying volume. Smoking causes no significant delay in GB refilling in both smokers and nonsmokers. These effects of smoking observed in acute phase result in bile stasis in GB. Bile stasis is the underlying cause of most GB disorders in chronic process.

Effects of sildenafil citrate (Viagra) on renal arteries: an evaluation with Doppler ultrasound.

INTRODUCTION: We aimed to determine hemodynamic alterations in renal arteries that may have resulted from oral intake of sildenafil citrate in healthy volunteers. MATERIALS AND METHODS: Twelve healthy volunteers were included in our study. Renal Doppler ultrasonography (US) was performed before the drug intake to assess the basal values. Maximum peak systolic velocity, and resistivity and pulsatility indices were measured from the segmental branches of both renal arteries in all the examinations. After the basal measurements 50 mg of sildenafil or placebo were randomly given to the 12 subjects. Renal Doppler US examinations were carried out 1 h after sildenafil or placebo intake. On the following day sildenafil was administered to the subjects who had previously taken placebo or vice versa. Renal Doppler US was repeated after 1 h. The effect of sildenafil on renal vascular hemodynamics was evaluated by comparison of basal values with postplacebo and postsildenafil values. RESULTS: No statistically significant differences were found between the basal values of bilateral renal arteries and maximum peak systolic velocity, and resistivity and pulsatility index values measured after the placebo or sildenafil intake. CONCLUSION: We demonstrated that single-dose sildenafil did not cause any significant effect on renal artery hemodynamics in healthy individuals.

Effect of sildenafil citrate on postprandial gallbladder motility.

OBJECTIVE: Sildenafil stimulates the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway through inhibition of type 5 phosphodiesterase. NO-cGMP pathway causes smooth muscle relaxation. The aim of this study is to evaluate the effects of sildenafil on gallbladder motility. METHODS: Twenty healthy male volunteers (21-35 years old) participated in this randomized, double blind, crossover, and placebo-controlled study. Oral sildenafil (50 mg) or placebo was randomly dispensed to each volunteer on two consecutive days. After the sildenafil or placebo, a special meal with a high fat content was administered. Gallbladder volume was measured using sonography preprandially and at 5, 15, 30, 60, 120 and 180 minutes postprandially. RESULTS: Sildenafil showed an inhibitory effect on gallbladder contraction in healthy volunteers that began at 30 minutes. Gallbladder volumes showed significant differences at 30 minutes following the test meal (approximately 50-60 min after the sildenafil intake), between placebo (15.4 +/- 5.1 mL) and the sildenafil groups (19.3 +/- 6.1 mL) (P < 0.05). In addition, gallbladder volume was significantly higher during the refilling phase in the sildenafil group (P < 0.05 at 180 min). Maximal contraction was achieved at 60 minutes in each group. CONCLUSIONS: Sildenafil constituted a significant inhibitory effect on gallbladder discharge in healthy individuals when compared with placebo group. Because of this inhibitory effect, sildenafil consumption for long periods may potentiate risks of gallbladder disorders and gallstone formation resulting from disturbed gallbladder motility.

Extracranial carotid Doppler ultrasound evaluation of cerebral blood flow volume in COPD patients.

OBJECTIVE: Doppler ultrasound of extracranial internal carotid artery (ICA) and vertebral artery (VA) were performed and total cerebral blood flow volume (tCBFV) was evaluated in chronic obstructive pulmonary disease (COPD) patients. CBFV changes due to blood gas changes were also evaluated. METHODS: Bilateral ICA and VA have been examined with 7.5 MHz linear array transducer in COPD patients. Angle-corrected time averaged flow velocity and cross-sectional areas of vessels have been measured. Flow volumes and tCBFV have been calculated. Flow velocities and waveform parameters have been measured. RESULTS: tCBFV, anterior-posterior CBFVs, left-right ICA flow volumes, bilateral ICA and VA cross-sectional areas and left ICA peak-systolic velocity were significantly higher in COPD patients than control group. Among COPD patients tCBFVs were highest in hypoxemic-hypercapnic ones, and lowest in normocapnic ones. Bilateral VA flow volumes, bilateral ICA (except left ICA V(ps)) and VA flow velocities and waveform parameters were not different in COPD patients compared with control group. When compared among the subgroups of COPD patients, there were no significant differences for all parameters. CONCLUSION: tCBFVs were found to be significantly higher in COPD patients. This increment which is probably due to balancing the oxygen deficit is low with hypoxemia and high with hypercapnia and hypoxemia. Particularly, bilateral ICA and VA cross-sectional area changes and increased left ICA V(ps) were considered as the main reason for increased tCBFV in COPD patients.

Evaluation of total cerebral blood flow volume in cerebral atrophy.

The goal of our study is to determine total cerebral blood flow volume (tCBFV) via extracranial Doppler ultrasound and to investigate its value in the differential diagnosis of dementia. Twenty-eight outpatients with cerebral atrophy confirmed by cranial computed tomography were enrolled into the study. Nine patients with Alzheimer's disease (AD) and nine patients with vascular dementia (VaD) based on neuropsychologic test and imaging findings, as well as 10 neurologically normal elderly subjects underwent Doppler sonographic examination of extracranial internal carotid artery (ICA) and vertebral artery (VA). Angle corrected time averaged flow velocity and cross-sectional areas of vessels have been measured. Flow volumes and tCBFV have been calculated. The measures of tCBFV, anterior CBFV (aCBFV), right CBFV (rCBFV) and right ICA flow volume were significantly lower in patients with dementia. The amounts of tCBFV, aCBFV, rCBFV and right ICA flow volume have been found to be low in AD and VaD patients compared with normal elderly group. Of all parameters measured for AD and VaD, no significant difference was found except Mini-Mental State Examination (MMSE) scores. To the best of our knowledge, this is the first reporting the CBF measurements using Doppler ultrasound of extracranial ICA and VA in the differential diagnosis of dementia in cerebral atrophy. The tCBFV, aCBFV, rCBFV and right ICA flow volumes and MMSE scores are significant in the diagnosis of dementia, whereas only MMSE scores are significant in the differential diagnosis of AD and VaD.