Stimulation of the right entorhinal white matter enhances visual memory encoding in humans.

BACKGROUND: While deep brain stimulation has been successful in treating movement disorders, such as in Parkinson's disease, its potential application in alleviating memory disorders is inconclusive. OBJECTIVE/HYPOTHESIS: We investigated the role of the location of the stimulating electrode on memory improvement and hypothesized that entorhinal white versus gray matter stimulation would have differential effects on memory. METHODS: Intracranial electrical stimulation was applied to the entorhinal area of twenty-two participants with already implanted electrodes as they completed visual memory tasks. RESULTS: We found that stimulation of right entorhinal white matter during learning had a beneficial effect on subsequent memory, while stimulation of adjacent gray matter or left-sided stimulation was ineffective. This finding was consistent across three different visually guided memory tasks. CONCLUSIONS: Our results highlight the importance of precise stimulation site on modulation of human hippocampal-dependent memory and suggest that stimulation of afferent input into the right hippocampus may be an especially promising target for enhancement of visual memory.

Does the Change in the Indications of Endoscopic Sinonasal Surgery Continue? Data between 1994-2018.

OBJECTIVE: Endoscopic sinonasal surgery (ESS) has changing over the years in parallel with the developments in endoscopy devices, video-imaging techniques, and surgical instruments. In the present study we investigated whether the indications of patients who underwent surgery over a period of 25 years have accommodated to these changes. METHODS: We retrospectively evaluated 1173 patients who underwent surgery in our clinic from 1994 through 2007, and 954 patients who underwent surgery from 2008 through 2018. The patients were divided into three groups as follows: chronic rhinosinusitis with polyps (CRSwNP), chronic rhinosinusitis without polyps (CRSsNP), and others. The changes in the indications during the first 14 years and the following 11 years were compared, and the results were statistically evaluated. RESULTS: A significant decrease was observed in the number of patients who underwent surgery following the diagnosis of CRSsNP (p<0.001). In addition, a statistically significant increase was found in CRSwNP (p<0.001) and other (p<0.001) indications. CONCLUSION: When ESS indications identified in our clinic were reviewed, it was observed that the increasing trend in CRSwNP rate in the first 14 years continued, there was a significant increase in non-CRS indications in the last 11 years, and there has been an increase in patients with fungal sinusitis, especially in this group.

Vestibular evoked myogenic potential responses in Parkinson's disease.

BACKGROUND AND PURPOSE: - Our objectives were to determine the differences in the vestibular evoked myogenic potential (VEMP) responses in patients diagnosed with early staged idiopathic Parkinson's disease (PD) compared to the normal population and evaluate the vestibular system disorder causing balance-posture disorders. Second aim of this study was to investigate caloric test responses particularly in early staged PD compared to normal popu-lation. METHODS: Thirty patients (14 females and 16 males; mean age, 60.6 ± 13.1 years) diagnosed with idiopathic PD and 28 healthy subjects (20 males and 8 females; mean age, 59.1 ± 6.4 years) were included. The patient and control groups were subdivided according to their age, gender and the patient group was subdivided according to onset time of the Parkinson symptoms, Hoehn-Yahr staging. The subgroups were compared for VEMP and caloric test responses. RESULTS: There were no significant differences between the study and control groups for right and left VEMP measurements. Patients over 60 years and under 60 years did not show significant differences in terms of right and left mean VEMP measurements. However, P1 amplitude was significantly lower in patients over 60 years old (P = .004). Gender, disease duration, BERG balance scale and Hoehn-Yahr stage had no effect on the VEMP amplitudes. There was no significant correlation with the side of Parkinsonian symptoms to the side of canal paresis (P = .566) and the side on which no VEMP response was obtained in caloric test. CONCLUSION: VEMP responses were not different between PD and healthy subjects. VEMP P1 amplitude was decreased with age in PD group. Canal paresis and symptoms side were not statistically correlated in caloric test.

Correlation of sleep-disordered breathing and laryngopharyngeal reflux: a two-channel triple-sensor pHmetry catheter study.

PURPOSE: To investigate the relationship between sleep-disordered breathing with gastroesophageal reflux (GER) and laryngopharyngeal reflux (LPR) using a two-channel triple-sensor pHmetry catheter. METHODS: The study was carried out on a total of 34 people with complaints of snoring, witnessed apnea and daytime sleepiness. 24-h pH monitoring with a two-channel, triple-sensor antimony pH catheter was applied to individuals simultaneously with polysomnography (PSG) on the day they would sleep in the sleep laboratory. Obstructive sleep apnea syndrome (OSAS) severity and reflux grade were compared with each other. Data obtained from PSG and pHmetry results were numerically compared with each other. The relationship between apnea, hypopnea, and arousal periods and reflux episodes was then examined by overlaying pHmetry graphics for each patient. RESULTS: A total of 34 individuals (18 males-52.9% and 16 females-47.1%), age ranging from 27 to 71 years (mean 50.5 ± 11.0) participated in the study. GER was detected in 52.9% and LPR in 85.3% of the patients. In 35.3% of cases, pathologic GER was not observed despite LPR detection. No statistically significant relationship was found between the numerical values of apnea-hypopnea index (AHI) and arousal numbers and reflux parameters of individuals and between OSAS severity and LPR and GER (p > 0.05). There was no statistically significant correlation between respiratory events and reflux episodes with regard to timing (p > 0.05). CONCLUSION: The prevalence of GER and LPR is found to be high in patients with sleep-disordered breathing. There is no significant relationship between OSAS severity and GER and LPR grade or respiratory events and reflux episodes with regard to timing.

Theta-burst microstimulation in the human entorhinal area improves memory specificity.

The hippocampus is critical for episodic memory, and synaptic changes induced by long-term potentiation (LTP) are thought to underlie memory formation. In rodents, hippocampal LTP may be induced through electrical stimulation of the perforant path. To test whether similar techniques could improve episodic memory in humans, we implemented a microstimulation technique that allowed delivery of low-current electrical stimulation via 100 µm-diameter microelectrodes. As thirteen neurosurgical patients performed a person recognition task, microstimulation was applied in a theta-burst pattern, shown to optimally induce LTP. Microstimulation in the right entorhinal area during learning significantly improved subsequent memory specificity for novel portraits; participants were able both to recognize previously-viewed photos and reject similar lures. These results suggest that microstimulation with physiologic level currents-a radical departure from commonly used deep brain stimulation protocols-is sufficient to modulate human behavior and provides an avenue for refined interrogation of the circuits involved in human memory.

Short-Range Temporal Interactions in Sleep; Hippocampal Spike Avalanches Support a Large Milieu of Sequential Activity Including Replay.

Hippocampal neural systems consolidate multiple complex behaviors into memory. However, the temporal structure of neural firing supporting complex memory consolidation is unknown. Replay of hippocampal place cells during sleep supports the view that a simple repetitive behavior modifies sleep firing dynamics, but does not explain how multiple episodes could be integrated into associative networks for recollection during future cognition. Here we decode sequential firing structure within spike avalanches of all pyramidal cells recorded in sleeping rats after running in a circular track. We find that short sequences that combine into multiple long sequences capture the majority of the sequential structure during sleep, including replay of hippocampal place cells. The ensemble, however, is not optimized for maximally producing the behavior-enriched episode. Thus behavioral programming of sequential correlations occurs at the level of short-range interactions, not whole behavioral sequences and these short sequences are assembled into a large and complex milieu that could support complex memory consolidation.

Speed modulation of hippocampal theta frequency correlates with spatial memory performance.

Hippocampal theta rhythm is believed to play a critical role in learning and memory. In animal models of temporal lobe epilepsy (TLE), there is evidence that alterations of hippocampal theta oscillations are involved in the cognitive impairments observed in this model. However, hippocampal theta frequency and amplitude at both the local field potential (LFP) and single unit level are strongly modulated by running speed, suggesting that the integration of locomotor information into memory processes may also be critical for hippocampal processing. Here, we investigate whether hippocampal speed-theta integration influences spatial memory and whether it could account for the memory deficits observed in TLE rats. LFPs were recorded in both Control (CTR) and TLE rats as they were trained in a spatial alternation task. TLE rats required more training sessions to perform the task at CTR levels. Both theta frequency and power were significantly lower in the TLE group. In addition, speed/theta frequency correlation coefficients and regression slopes varied from session to session and were worse in TLE. Importantly, there was a strong relationship between speed/theta frequency parameters and performance. Our analyses reveal that speed/theta frequency correlation with performance cannot merely be explained by the direct influence of speed on behavior. Therefore, variations in the coordination of theta frequency with speed may participate in learning and memory processes. Impairments of this function could explain at least partially memory deficits in epilepsy.

Congenital bilateral parotid gland agenesis in Klinefelter syndrome.

Bilateral parotid gland agenesis is a rare clinical entity and it's an etiopathogenesis remains obscure. The literature contains no reports of the co-existence of bilateral parotid gland agenesis and Klinefelter syndrome. The condition is usually asymptomatic and causes asymmetry in the head and neck areas. Its diagnosis is generally made in the light of accompanying developmental anomalies. Herein we report the clinical and radiological findings of a 17-year-old male with Klinefelter syndrome accompanied by unilateral peripheral facial nerve paralysis and isolated congenital bilateral parotid gland agenesis.

Atypical lipomatous tumor in the submental region.

A 54-year-old male patient presented to our outpatient clinic complaining of a mass under his chin, which appeared nearly 1 year earlier. Pathologic diagnosis was atypical lipomatous tumor. To the best of our knowledge, this is the first reported case to localize subcutaneously in the head and neck region. Atypical lipomatous tumors/well-differentiated liposarcomas are rarely reported in the head and neck. We review the clinical and management features of atypical lipomatous tumors.

Sensorineural hearing loss after radiotherapy for head and neck tumors: a prospective study of the effect of radiation.

INTRODUCTION: In the treatment of head and neck cancers, the cochlea may be damaged if it is within the radiotherapy (RT) area; however, the severity and mechanism of such damage have yet to be clearly defined. The purpose of this study was to analyze the rates of early- and late-stage sensorineural hearing loss (SNHL) in patients receiving RT due to head and neck cancer and to investigate the reliability of distortion product otoacoustic emissions (DPOAEs) measurements and audiometric evaluation. STUDY DESIGN: Prospective. METHOD: The study included 38 ears of 19 patients scheduled for RT due to head and neck cancer diagnoses. The patients received RT at a fractioned dose of 200 cGy (5 d/wk) and were evaluated pretreatment and posttreatment (1st and 12th mo), both audiometrically and with DPOAE measurement. Any decrease greater than 10 dB was considered SNHL. The amplitudes of DPOAE measurements were statistically compared. RESULTS: The audiometric evaluation performed in the 1st posttreatment month showed no SNHL in any of the patients, whereas in the 12th month, 47% of the ears had SNHL. In all the patients that developed SNHL, the amplitudes obtained in DPOAE measurements in the first posttreatment month were statistically significantly lower. CONCLUSION: The results of the present study show that DPOAE measurement is a reliable method for determining which patients are at risk of developing SNHL in the early post-RT period.

Meningoencephalocele as a rare cause of cerebrospinal fluid fistula during dacryocystorhinostomy.

A meningoencephalocele is a herniation of meninges and brain out of the cranial fossa through a bony defect. Cerebrospinal fluid leakage may occur due to a defect in the wall of the meningoencephalocele. The defect may be traumatic, iatrogenic, or may appear spontaneously. In this report, the authors present an unrecognized transethmoidal meningoencephalocele that resulted in a cerebrospinal fluid leak during dacryocystorhinostomy.

The effects of merocel and glove finger tampon applications on the nasal septum mucosa of rabbits.

OBJECTIVE: The use of tampons after nasal septum surgery is important for both prevention of postoperative bleeding and stabilization of the nasal flaps and the septum. One of the most important factors in achieving rapid postoperative recovery is the choice of the nasal tampon material, among many, to produce minimal damage on the nasal mucosa. In this study, the histopathological effects of the glove finger and merocel tampons, which are commonly used in clinical applications, have been investigated on the nasal mucosa of rabbits. MATERIALS AND METHODS: In this study, merocel and glove finger tampons were used for nasal packing in one-sided nasal cavities of 16 adult New Zealand rabbits. The animals were randomized into two groups, each consisting of eight animals. The tampons were removed after 48 hours. RESULTS: Histological examination showed that if the merocel was in a glove finger, it did not create any damage to mucosal integrity and lamina propria. However, in the group where merocel was used directly, the epithelium of the nasal mucosa was shortened and demonstrated loss of cilia and in four of the eight specimens, it was partly from lamina propria. CONCLUSION: It is concluded that the use of merocel in glove finger tampon leads to a lesser degree of damage in the lamina propria, and may facilitate rapid mucosal wound healing postoperatively.

Development of maxillary accessory ostium following sinusitis in rabbits.

OBJECTIVES/HYPOTHESIS: Maxillary accessory ostium is one of the anatomical variations that may play a role in the development of chronic maxillary sinusitis. Although some authors claim that accessory ostia develop following acute maxillary sinusitis, it is not clear whether they are congenital or acquired. STUDY DESIGN: Animal experimental study. METHODS: Ten New Zealand type rabbits were used in the study. In phase 1, lateral nasal walls of five New Zealand type rabbits were examined for the presence of natural and accessory ostia of the maxillary sinus and any area resembling fontanelles in humans. In phase 2, experimental sinusitis was induced in the right sides of the other five rabbits. Following sacrifice, lateral nasal walls were examined for the development of accessory ostia. RESULTS: Six of the ten sides of phase 1 animals contained a membranous part in the medial wall of the maxillary sinus resembling the fontanelles in humans (60%). None of them had an accessory maxillary ostium. Accessory ostia developed in two of the five sides with sinusitis (40%). CONCLUSIONS: We have shown for the first time that accessory maxillary ostia develop following experimental sinusitis in rabbits. Further studies in humans are indicated.

The presence of Helicobacter pylori in the larynx pathologies.

OBJECTIVE: The well-known relation of Helicobacter pylori to the MALT-lymphoma and gastric carcinoma suggested a possible presence in the laryngeal tissues of patients with squamous cell carcinoma of the larynx by using Polymerase Chain Reaction (PCR) investigations, and PCR results of benign laryngeal pathologies were compared. METHODS: Polymerase Chain Reaction investigations were carried out in biopsy samples of 21 patients with squamous cell carcinoma of the larynx and of 19 patients with benign laryngeal pathologies like vocal polyp and nodules. RESULTS: The PCR results of 17 out of the 21 samples (80.9%) of the patients with laryngeal squamous cell carcinoma were positive for H. pylori. Moreover, any genomic material of H. pylori was not found in the PCR results of the 19 patients with benign laryngeal pathology. It was also determined that the presence of the H. pylori in the patients with laryngeal squamous cell carcinoma was statistically significant (p=0.0001). In the patients with laryngeal squamous cell carcinoma, the comparison of the H. pylori presence within the normal and tumoral tissues revealed that 16 normal tissue samples (76.19%) were positive, while 9 of the tumoral tissue samples (42.85%) were positive. The ratio of bacterial presence in both the normal and tumor tissue samples was 38.09% (8 patients). The rates of presence revealed a statistically significant difference between the normal and tumoral tissue samples (p=0.039). CONCLUSIONS: The presence of the genomic material of H. pylori within the laryngeal tissue of patients with squamous cell carcinoma of the larynx is a proof of the colonization of the bacterium in that tissue. While this may suggest a possible relation of the bacterium to the development of laryngeal squamous cell carcinoma, no conclusion is possible to be drawn about the mechanism of the process.

Comparison of levo-bupivacaine and lidocaine for postoperative analgesia following septoplasty.

The aim of this study is to compare the efficacy of levo-bupivacaine, a long-acting local anesthetic and lidocaine in postoperative analgesia following septoplasty. 112 patients randomized into two groups were included in the study. 56 patients were operated using levo-bupivacaine and 56 using lidocaine as the local anesthetic. All patients were asked to mark their pain levels on a Visual analogue scale (VAS) at 1st, 2nd, 4th, 6trh 8th, 12th, and 24th hours postoperatively. In addition, the amount of analgesics used by each patient was recorded. The results indicated that the VAS scores of the levo-bupivacaine patients were significantly lower within the postoperative 4 hours (p < 0.05) compared to the lidocaine group. In the levobupivacaine patients the earliest time for analgesic need was delayed (p < 0.001) and the total amount of analgesics used was significantly lower when compared to lidocaine group (p < 0.001). In conclusion, levo-bupivacaine is effective for obtaining postoperative analgesia following septoplasty with local anesthesia. When compared to lidocaine, it increases the postoperative comfort of the patients by reducing pain levels.

Can postoperative pains following tonsillectomy be relieved by honey? A prospective, randomized, placebo controlled preliminary study.

OBJECTIVE: To compare the effectiveness of acetaminophen versus acetaminophen-plus-honey following pediatric tonsillectomy and adenoidectomy. DESIGN: Prospective, randomized, and placebo controlled clinical trial. SETTING: Tertiary care facility in Ankara, Turkey. PATIENTS: Sixty consecutive tonsillectomy patients randomized to two groups. INTERVENTIONS: The acetaminophen group was treated with antibiotics (amoxicillin-clavulonic acid), acetaminophen and placebo, acetaminophen-plus-honey group was treated with antibiotics (amoxicillin-clavulonic acid), acetaminophen, and honey. Visual analogue scale (VAS) was applied for subjective assessment of postoperative pains, while the number of painkillers taken daily and awakening at night due to pain were used for objective assessment. The amount of epithelization was used for assessment of tonsillary fossa recovery. OUTCOME MEASURES: The difference between acetaminophen and acetaminophen-plus-honey groups was statistically significant both in terms of VAS and number of painkillers taken within the first 2 postoperative days (p<0.001). Although there was no statistically significant difference between groups regarding the VAS scores on the 3rd postoperative day and after, the number of painkillers taken differed significantly until the 8th postoperative day (p<0.001 for first 7 postoperative days; p=0.003 for 8th day). No significant difference was found between groups regarding the number of awakening at night (p=0.36). Tonsillary fossa epithelization was more rapid in the acetaminophen-plus-honey group (p<0.001). CONCLUSION: Oral administration of honey following pediatric tonsillectomy may relieve postoperative pain and may decrease the need for analgesics. Prospective, randomized, and double-blind studies should further be conducted in order to confirm the data obtained in this study and develop a standard protocol to achieve maximum clinical efficiency.