The value of qualitative and quantitative assessment of lesion to cerebral cortex signal ratio on double inversion recovery sequence in the differentiation of demyelinating plaques from non-specific T2 hyperintensities.

OBJECTIVES: To assess the usefulness of the visual assessment and to determine diagnostic value of the lesion-to-cerebral cortex signal ratio (LCSR) measurement in the differentiation of demyelinating plaques and non-specific T2 hyperintensities on double inversion recovery (DIR) sequence. MATERIAL AND METHODS: DIR and fluid-attenuated inversion recovery (FLAIR) sequences of 25 clinically diagnosed multiple sclerosis (MS) patients and 25 non-MS patients with non-specific T2-hyperintense lesions were evaluated visually and LCSRs were measured by two observers independently. RESULTS: On DIR sequence, the calculated mean LCSR ± SD for demyelinating plaques and non-specific T2-hyperintense lesions were 1.60 ± 0.26 and 0.75 ± 0.19 for observer1, and 1.61 ± 0.27 and 0.74 ± 0.19 for observer2. LCSRs of demyelinating plaques were significantly higher than other non-specific T2-hyperintense lesions on DIR sequence. By using the visual assessment demyelinating plaques were differentiated from non-specific T2-hyperintensities with 92.8 % sensitivity, 97.5 % specificity and 95.1 % accuracy for observer1 and 92.8 % sensitivity, 95 % specificity and 93.9 % accuracy for observer2. CONCLUSION: Visual assessment and LCSR measurement on DIR sequence seems to be useful for differentiating demyelinating MS plaques from supratentorial non-specific T2 hyperintensities. This feature can be used for diagnosis of MS particularly in patients with only supratentorial T2-hyperintense lesions who are categorized as radiologically possible MS. KEY POINTS: • Demyelinating plaques and non-specific T2-hyperintensities have different SI on DIR images. • These differences can be assessed by LCSR measurement or visual assessment. • There is an excellent inter-observer agreement for both methods. • This feature can be used in radiologically possible MS cases.

Association of nerve conduction impairment and insulin resistance in children with obesity.

AIM: The objective of our study was to investigate nerve conduction in normoglycemic obese children. METHODS: A total of 60 children with obesity (30 female and 30 male) and 30 healthy children (15 female and 15 male) were enrolled in the study. Insulin resistance (IR) and other metabolic disturbances were investigated and nerve conduction was measured in all participants. Obese children were divided into groups according to the presence of IR. All results were compared between these subgroups. RESULTS: The nerve conduction velocity (NCV) of motor median nerves in the IR+ group was significantly higher than that in the IR- group and lower than that in the control group. The NCV of the motor peroneal nerve in the IR+ group was significantly lower than that in the IR- group. The sensory nerve action potential (SNAP) of the sensory median nerve was significantly lower in the IR+ group compared to that in the IR- group. The sensory sural nerve's SNAP was significantly lower in the IR+ group than that in the control group. CONCLUSION: Nerve conduction tests may help to detect early pathologies in peripheral nerves and to decrease morbidities in obese children.

The effect of nasal polyposis related nasal obstruction on cognitive functions.

Chronic rhinosinusitis with nasal polyposis is a chronic inflammatory disease of the respiratory mucosa of the nasal cavity and paranasal sinuses. The aim of this study was investigate the effect of nasal obstruction related to chronic rhinosinusitis with nasal polyposis on cognitive functions. Patients with chronic rhinosinusitis with nasal polyposis causing bilateral total or near total nasal obstruction were enrolled in the study. Symptoms of nasal congestion, loss of smell, postnasal drip, headaches, snoring, concentration difficulties and blunted affect were evaluated by Visual Analog Scale. Brief symptom inventory test, Stroop test, visual aural digit span, serial digit learning test and P300 test were used to evaluate cognitive functions. Three months after treatment, the tests done before surgery were repeated and the results were compared. A total of 30 patients were included in the study. On the Visual Analog Scale, all symptoms showed significant postoperative improvement in all patients (p < 0.001 for all symptoms). Preoperative nasal congestion accompanied with impaired concentration were detected in 27 patients (90%), and these symptoms recovered in all these patients after treatment (p = 0.035) (correlation coefficient 0.4). Only 22 patients completed the neuropsychological tests. The mean preoperative Stroop test (23.16 ± 5.30), visual aural digit span test (24.68 ± 3.52), and serial digit learning test (16.18 ± 5.35) scores were showed significant improvement compared with mean postoperative Stroop test (21.12 ± 5.69), visual aural digit span test (26.45 ± 2.98), and serial digit learning test (19.31 ± 4.47) scores (p = 0.047, p = 0.022, p = 0.005 respectively). The postoperative P300 latency values improved in 19 (63%) patients. The preoperative and postoperative latency values for P300 showed a significant difference (p = 0.029), whereas the preoperative and postoperative amplitude values for P300 did not differ (p = 0.096). In conclusion, the results of this study indicate that chronic rhinosinusitis with nasal polyposis (CRSwNP) has negative effects on cognitive functions, such as the ability to focus and maintain concentration. These cognitive functions improve after the patients undergo endoscopic sinus surgery to treat their CRSwNP.

Decreased cerebral vasomotor reactivity in patients with obstructive sleep apnea syndrome.

OBJECTIVE: In obstructive sleep apnea syndrome (OSAS), any of the activated neural, vascular, hemodynamic, metabolic, inflammatory, and thrombotic mechanisms may be related to increased cerebrovascular disease and risk of death; however, the possible pathophysiological process between obstructive sleep apnea syndrome and stroke has not been clearly explained. We hypothesize that alterations in vasomotor reactivity in patients may be responsible for their altered cerebral blood flow, and may contribute to the increased risk of ischemic stroke. METHODS: A total of 30 untreated patients with severe obstructive sleep apnea and 26 control subjects were included in the study. The mean blood flow velocity and breath holding index were measured in middle cerebral artery bilaterally in both patient and control groups by using transcranial Doppler ultrasound. We compared the values between two groups. RESULTS: The mean blood flow velocity and breath holding indexes were significantly decreased in the patient group when compared with the control group. There were no correlations between cerebral hemodynamic parameters and polysomnographic findings in patients. CONCLUSION: Our findings suggest that there was a deteriorated vasodilator response to hypercapnia in patients with OSAS. This deterioration may stem from chemoreceptors or endothelial damages that lead to vascular relaxation and vasodilatation in cerebrovascular circulation. This impaired cerebral vascular regulation may contribute to the increased risk of stroke in patients with OSAS.

Reduced breath holding index in patients with chronic migraine.

Migraine is a neurovascular disorder characterized by autonomic nervous system dysfunction and severe headache attacks. Studies have shown that changes in the intracranial vessels during migraine have an important role in the pathophysiology. Many studies have been conducted on the increased risk of stroke in patients with migraine, but insufficient data are available on the mechanism underlying the increase. This study aimed to evaluate basal cerebral blood flow velocity and vasomotor reactivity in patients with chronic migraine. We evaluated 38 patients with chronic migraine. Three of them were excluded because they had auras and four of them were excluded because of their use of medication that can affect cerebral blood flow velocity and breath holding index (beta or calcium channel blockers). Our study population consisted of 31 patients with chronic migraine without aura and 29 age- and gender-matched healthy individuals who were not taking any medication. The mean blood flow velocity and breath holding index were measured on both sides from the middle cerebral artery and posterior cerebral artery, with temporal window insonation. The breath holding index for middle cerebral artery and posterior cerebral artery was significantly lower in the migraine group compared to that of the control group (p < 0.05).The vasomotor reactivity indicates the dilatation potential of a vessel, and it is closely related to autoregulation. According to our results, the vasodilator response of cerebral arterioles to hypercapnia was lower in patients with chronic migraine. These findings showed the existence of impairments in the harmonic cerebral hemodynamic mechanisms in patients with chronic migraine. This finding also supports the existing idea of an increased risk of stroke in patients with chronic migraine due to impaired vasomotor reactivity.

The critical role of spinal 5-HT7 receptors in opioid and non-opioid type stress-induced analgesia.

The opioid and non-opioid types of stress-induced analgesia have been well defined. One of the non-opioid type involve the endocannabinoid system. We previously reported that the spinal serotonin 7 receptor (5-HT7) blockers inhibit both morphine and cannabinoid-induced analgesia, thus we hypothesized that descending serotonergic pathways-spinal 5-HT7 receptor loop might contribute to stress-induced analgesia. Stress-induced analgesia was induced with warm (32°C) or cold (20°C) water swim stress in male Balb-C mice. The effects of intrathecal injection of a selective 5-HT7 receptor antagonist, SB 269970, of the denervation of serotonergic neurons by intrathecal administration of 5,7-dihydroxytryptamine (5,7-DHT) and of lesions of the dorsolateral funiculus on opioid and non-opioid type stress-induced analgesia were evaluated with the tail-flick and hot plate tests. The expression of 5-HT7 receptors mRNA in the dorsal lumbar region of spinal cord were analyzed by RT-PCR following spinal serotonin depletion or dorsolateral funiculus lesion. The effects of the selective 5-HT7 receptor agonists LP 44 and AS 19 were tested on nociception. Intrathecal SB 269970 blocked both opioid and non-opioid type stress-induced analgesia. Dorsolateral funiculus lesion or denervation of the spinal serotonergic neurons resulted in a marked decrease in 5-HT7 receptor expression in the dorsal lumbar spinal cord, accompanied by inhibition of opioid and non-opioid type stress-induced analgesia. However, the systemic or intrathecal LP 44 and AS 19 alone did not produce analgesia in unstressed mice. These results indicate that descending serotonergic pathways and the spinal 5-HT7 receptor loop play a crucial role in mediating both opioid and non-opioid type stress-induced analgesia.