The COVID-19 Pandemic and Elective Spine Surgery-A Single Center Experience.

Background and objective: The COVID-19 pandemic had a profound impact on medical practice worldwide. In this study, we aimed to investigate the trends of elective spine surgery in our department before and during the pandemic. Materials and methods: Total number of spine procedures due to disc herniation (DH) or spinal stenosis (SS) was collected during 2019-2021 in the Department of Neurosurgery, University Hospital Center Osijek, Croatia. In order to elucidate potential risk factors in the post-pandemic period, demographic data were collected for patients who underwent surgery during 2021. Results: In 2020, there was a 22.1% decrease in the number of surgeries compared to 2019 (205 vs. 263), but during 2021 we observed an increase of 36.1% compared to 2020 (279 vs. 205). The mean age of patients in 2021 was 53.14 years (53.14 ± 13.05) with body mass index of 28.31 kg/m2 (28.31 ± 4.89). There were 179 overweight patients (74%) and 103 smokers (42.6%). Although male and female patients were equally represented (121 each), there was a significant interaction of weight class and sex (p = 0.013). Patients younger than 65 were more likely to undergo surgery due to DH (p < 0.001), whereas older patients were more likely to suffer from SS (p < 0.001). Conclusions: The volume of elective spine surgeries decreased in the first year of the pandemic and increased the following year. Our results suggest that public health policies in the early pandemic period reduced elective surgical procedures, which was followed by a compensatory increase in the following period.

Are the Persistent Postural-Perceptual Dizziness (PPPD) Patients More Anxious than the Patients with Other Dizziness?

BACKGROUND: The Behavioral Subcommittee of the Bárány Society Committee for Classification of Vestibular Disorders recently established the diagnostic criteria for a persistent postural-perceptive dizziness (PPPD). OBJECTIVES: This study aims to determine how significant the degree of anxiety and depression of PPPD patients is, compared to the patients with other dizziness. SUBJECTS AND METHODS: The study was conducted on 78 patients, 39 (50%) of whom suffer from PPPD, and of a control group consisting of the same number of patients with other types of dizziness. All the patients filled out the DHI and HADS questionnaire and were subjected to a VNG and VEMP examination. RESULTS: The DHI showed significant disability in the majority of patients, slightly more in the control group. The HADS showed an equal degree of anxiety in both groups of patients, but significantly higher pathological anxiety in the PPPD group (49%:31%). CONCLUSIONS: Majority of the patients in both groups experienced mild anxiety, while those with the pathological degree were more represented in the PPPD group. Depression was more expressed in the group of other dizziness. We can consider only the patients with a pathological degree of anxiety as predisposed to the emergence of PPPD.

FACTORS AFFECTING OUTCOME IN THE TREATMENT OF GLIOBLASTOMA.

Treatment of glioblastoma is challenging due to its aggressive and highly invasive nature, and no significant advances in survival have been achieved recently. The aim of our retrospective study was identification of predictive factors and consequent survival outcome in patients who underwent surgical and oncologic treatment of glioblastoma. The study was conducted at the Department of Neurosurgery, Osijek University Hospital Centre. The authors designed a retrospective cohort study in 63 patients who underwent surgical and oncologic treatment between January 1, 2012 and December 31, 2017. Data were collected by reviewing medical records of the patients with histologically proven glioblastoma. Statistical analysis of study results revealed a significant impact of postoperative radiotherapy (p=0.002) and chemotherapy (p=0.016) on progression-free survival and overall survival (p=0.001 and p=0.009, respectively). Postoperative Karnofsky performance scale (p=0.027) was found to be significant in progression-free survival, and so was the interval between surgery and commencement of oncologic therapy (p=0.049). In conclusion, overall survival and prognosis in the treatment of glioblastoma remain poor, although prompt approach in postoperative adjuvant treatments improved progression-free survival.

POSTERIOR PENETRATING INJURY OF THE NECK: A CASE REPORT.

- A 45-year-old male patient was admitted to the emergency unit due to posterior stab wound of the neck. The knife was directed diagonally from the left to the right side of the neck in the dorsoventral axis. The patient was fully conscious upon admission with pain and paresthesia along the upper right extremity. The patient underwent computed tomography (CT) and CT angiography scan of the neck, which revealed the knife blade piercing the left sided neck muscles and through the intervertebral ligaments of the C IV/C V in direction to the contralateral internal carotid artery, vertebral artery and the C5 nerve root. The patient underwent an urgent surgery according to the radiographs. Electromyography was performed during the early postoperative care and revealed an acute lesion of the right-sided C5 nerve root. Postoperative follow-up magnetic resonance imaging revealed intact brachial plexus bundles at the site of injury. Symptoms of reduced muscle strength and limited range of motion of the upper right extremity prevailed. Penetrating neck injuries represent a rare entity of all trauma injuries. Meticulous preoperative radiographs revealed close proximity of the knife blade tip to the right-sided vertebral artery and common carotid artery. Limited abduction at the right shoulder during postoperative period correlated to the C5 nerve root injury.

Health-related quality of life and ways of coping with stress in patients with migraine.

The aim of our study was to examine the relationship between the mode of coping and health-related quality of life (HRQoL) in patients with migraine. We have also tried to examine the relationship of disease duration and the frequency of attacks with HRQoL and the ways of coping with stress. The research was done on a sample consisting of 106 participants (95 women and 11 men); mean age of 40 years (IQR 28-48) with the migraine lasting for 10 years (IRQ 5-20 years). The average number of attacks, over the last month, was two attacks (IRQ 1-3 attacks). Ways of coping questionnaire were used to estimate the mode of coping with stress and SF-36 questionnaire for HRQoL. The result showed the self-control as the most common way of coping with stress in patients with migraine. They also confirmed the existence of a significant connection of ways of coping with stress and HRQoL in people with migraine. There is a larger number of significant correlations of ways of coping connected with the domains of mental health than with the physical health. Escape/avoidance is significantly negatively correlated with the largest number of HRQoL domains, especially with existence of significant mental health (ρ = -0.447) and role limitation due to the emotional problems (ρ = -0.361). The number of migraine attacks has greater influence on HRQoL in patients with migraine than the disease duration. Our study showed the existence of significant correlations between the ways of coping with stress and HRQoL, especially with mental domains. In some domains, the correlation was even stronger than the one showing the disease duration and the number of attacks. The above-mentioned results suggest the directions in further formulation of psychological interventions that would be helpful for the additional treatment of migraine.

Tongue somatosensory evoked potentials reflect midbrain involvement in patients with clinically isolated syndrome.

AIM: To test the hypothesis that tSSEP findings reflect clinical and MRI MS lesions, the aim of this study was to investigate tSSEP changes in patients with clinically isolated syndrome (CIS) in relation to clinical and brainstem MRI findings. The second aim was to investigate whether the interpretation of the tSSEP results in the form of the tSSEP score enables better evaluation of the afferent trigeminal pathway involvement than analyzing each tSSEP parameter separately. METHODS: 115 consecutive CIS patients were enrolled from August 1, 2014 until March 1, 2016. Facial sensory symptoms and brainstem MRI (1.5 T) lesions were analyzed. tSSEP testing was performed for each patient from the raw tSSEP data. The tSSEP score was calculated separately for the left and right side (according to the cut-off values for absent response and prolonged latency of the main component, P1 (0=normal response, 1=prolonged latency, 3=absent response) and the two values were summed. RESULTS: There was no difference in the absolute values of the tSSEP variables regarding the presence of clinical symptoms. No association was found between tSSEP abnormalities and clinical symptoms (P=0.544). Brainstem lesions (midbrain and pons) were associated with the absent tSSEP responses (P=0.002 and P=0.005, respectively). tSSEP score was significantly higher in patients with brainstem lesions (P=0.01), especially midbrain (P=0.004) and pontine (P=0.008) lesions. Binary logistic regression showed that tSSEP score had a significant effect on the likelihood that patients have midbrain MR lesions, ?2(1)=6.804, P=0.009; and the model correctly classified 87% of cases. CONCLUSIONS: The consistent finding of this study was the association between tSSEP and midbrain lesions on MRI, indicating that tSSEP evaluates proprioception of the face. This study establishes the value of tSSEP in assessing brainstem function in early multiple sclerosis.

Stroke Caused by Lung Cancer Invading the Left Atrium.

We describe a 59-year-old stroke patient presented with sudden onset left side weakness and a speech disorder due to a major acute cerebral infarction in the area of the right middle cerebral artery, right posterior cerebral artery, and small infarctions in the area of the left middle and left posterior cerebral artery. For the previous month, the patient had been feeling weak and had no appetite. The patient had not been previously seriously ill. A chest x-ray showed a large mass in the upper zone of the right lung. Chest computed tomography scan and echocardiography were performed and revealed advanced lung cancer invading the left atrium. Spontaneous tumor embolism is a rare cause of stroke and should be considered in the differential diagnosis of stroke in a cancer patient. Also, sometimes stroke can be the first manifestation of advanced cancer.

Transcranial sonography and the pocket smell test in the differential diagnosis between parkinson's disease and essential tremor.

The aim of this study was to determine the specificity and sensitivity of transcranial sonography (TCS) and the Pocket Smell Test (PST) in differing Parkinson's disease from essential tremor. The results were compared with the dopamin transporter scan (DaTSCAN) findings. Based on the DaTSCAN finding we formed a group of patients with essential tremor (51 patients) and a group with the Parkinson's disease (59 patients). The control group consisted of 26 healthy one. To evaluate the olfactory dysfunction the PST was used, whereas by TCS the substantia nigra hyperechogenicity was marked. The sensitivity and specificity of each diagnostic method was statistically calculated. In confirming Parkinson's disease the specificity of TCS was 88.2 % and the sensitivity 94.9 %. The specificity of PST was 80.4 % whereas the sensitivity was 74.6 %. TCS and PST should be performed to evaluate which patients need to be examined by DaTSCAN.

Type I persistent proatlantal artery associated with fusiform subclavian artery aneurysm: Report of one case.

We report a 61 years old male presenting with a right cerebral infarction, along with a type I persistent left proatlantal artery (PA), which is a form of primitive carotid-basilar anastomosis. The patient had an absence of the ipsilateral vertebral artery (VA) and hypoplasia of the contralateral VA, while the basilar artery was supplied by the PA. Other vascular anomalies present were a fusiform aneurysm of the right subclavian artery, and an A1 segment aplasia of the hypoplastic anterior right cerebral artery, which originated from the anterior communicating artery. To our knowledge these anomalies were not described previously.

[CROATIAN GUIDELINES FOR DIAGNOSIS AND MANAGEMENT OF BENIGN PAROXYSMAL POSITIONAL VERTIGO (BPPV)]. / HRVATSKE SMJERNICE ZA DIJAGNOSTIKU I LIJECENJE BENIGNOGA PAROKSIZMALNOG POZICIJSKOG VERTIGA (BPPV-A).

BPPV is generally the most common cause of vertigo, caused by a pinch-off of tiny calcium carbonate crystals (called the otoconia or the otoliths) from the macula utriculi, most frequently due to the degenerative processes or a trauma, whereby the crystals, under the action of gravity in certain head positions coinciding with its direction, arrive to some of the semicircular canals, usually the posterior one, due to the existent anatomical circumstances and relationships, thus creating an inadequate stimulus of the cupular senses while floating through the endolymph and provoking symptoms of a strong and short-term dizziness. Two main clinical forms can be distinguished: canalolythiasis, with an accommodation of otolithic debris in the semicircular canal, and cupulolythiasis, with their location immediately next to the cupular sense. The diagnosis is established by a positive positioning test, Dix-Hallpike for the posterior and the supine roll for the lateral canal. Although one can expect a spontaneous recovery subsequent to few weeks or months, various methods of otolith repositioning to a less sensitive place lead to a prompt improvement while reducing or withdrawing the symptoms completely. These guidelines are intended for all who treat the BPPV in their work, with an intention to assist in the diagnosis and application of an appropriate therapeutic method.

The impact of the comorbid seizure/epilepsy on the health related quality of life in people with multiple sclerosis: an international multicentric study.

Introduction: The health-related quality of life (HRQoL) of people with (Pw) multiple sclerosis (MS) is usually deteriorated. It has been recently suggested that comorbidities may have the negative influence on the quality of life of the PwMS, but according to the best of our knowledge, only one study investigated, although in a very small cohort, the impact of individual comorbidity on the quality of life of PwMS. The aim of our investigation was to assess, in an international, multicentric study, the impact of comorbid seizure/epilepsy on the HRQoL in PwMS. Methods: We conducted cross-sectional study at numerous neurological centers in Serbia, Croatia, Bulgaria, Montenegro, Northern Macedonia, and Bosnia and Herzegovina (Federation of Bosnia and Herzegovina and Republic of Srpska). For each patient, demographic and clinical data were collected, including Expanded disability status scale (EDSS) score. Beck Depression Inventory (BDI) and the 36-Item Short Form Health Survey (SF-36) questionnaires were administered to all patients. Results: The study comprised 326 PwMS in total, 127 PwMS with seizure/epilepsy and 209 PwMS without. Both mean Physical health composite (PHC) and mental health composite (MHC) scores, were statistically significantly higher in PwMS without seizure/epilepsy, implicating worse quality of life in PwMS with comorbid seizure/epilepsy. Presence of seizure/epilepsy in pwMS was statistically significant independent predictor of both PHC and MHC, in multivariate linear regression model after adjustment for potential confounding variables. The hierarchical multivariate regression analysis was performed in order to establish the most important predictors of the PHC and MHC of the SF-36, in PwMS with seizure/epilepsy; older age, higher level of disability, as measured by EDSS, higher depression score, drug-resistant epilepsy and shorter time since last seizure were found to significantly predict worse MHC score in PwMS with seizure/epilepsy. Discussion: Our results point to the possible role of theinterventions related to the adequate control of epilepsy along with improvement of the mental health status to be important in order to reduce MS burden in the PwMS with comorbid seizure/epilepsy.

Ultrasound evaluation of extracranial carotid artery lesions in Parkinsonian patients.

The purpose of this investigation was to determine the atherosclerotic changes in patients with vascular parkinsonism and in patients with idiopathic Parkinson's disease, in order to evaluate the possible influence of the extracranial pathology of carotid arteries in developing lacunar cerebral infarcts. Degree of stenosis and plaque morphology of the extracranial part of carotids in both group of patients were evaluated by color Doppler flow imaging ultrasound investigation and the results were compared. We selected two matched groups of patients with parkinsonism: 22 patients with vascular parkinsonism, and 28 with idiopathic Parkinson's disease.The atherosclerotic changes found in patients with Parkinson's disease showed mild carotid lesions with mostly stable calcified plaques and lesser risk for embolic cerebral intravascular events contrary to the higher degree of carotid stenosis found in patients with vascular parkinsonism with mostly mixed plaques prone to embolization. Therefore, we suggest performing ultrasonographic examination of the extracranial part of carotid arteries in all patients with parkinsonism to assess risk of vascular accidents originating from carotid lesions. That would enable adequate treatment of parkinsonism and prevent further occurrence of intracranial vascular changes.

Total Antioxidant Status in Stable Chronic Obstructive Pulmonary Disease.

Objective: This study evaluates the total antioxidant status (TAS) in plasma of stable chronic obstructive pulmonary disease (COPD) patients. Earlier studies of their relationship showed inconsistent findings. Patients and Methods: We compared TAS between 90 COPD patients and 30 age- and sex-matched controls (mean age 67 ± 7.9, 87 males and 33 females) according to airway obstruction severity, gender, smoking status (current/ former/ non-smoker), smoking-dose, the number of exacerbations in the previous year, nutritional status and hypercapnia. Results: There were no differences in pack-years between COPD and controls, neither in COPD groups. The median time from the last exacerbation was 5 months (interquartile range 3-8.3). TAS was significant higher in COPD than controls (1.68 [1.55-1.80] versus 1.59 [1.54-1.68], respectively; P = 0.03). TAS was significantly higher in COPD men than women (1.7 [1.6-1.8] versus 1.57 [1.5-1.7], respectively; P = 0.001). In COPD groups, there were no significant differences between the severity of airway obstruction and TAS. We found significant positive correlation between pack-years and TAS in all participants (Rho = 0.429, P = 0.004) and COPD patients (Rho = 0.359, P = 0.02), but not in controls. TAS was a significant predictor of COPD (ß = 3.26; P = 0.04; OR = 26.01; 95% CI: 1.20 to 570.8). We failed to find significant differences between TAS and smoking status, frequency of exacerbations in the previous year, nutritional status and hypercapnia. Conclusion: TAS was a significant predictor of COPD. TAS was a significantly higher in stable COPD than controls, higher in COPD men than women, but there was no significant correlation between TAS and the airway obstruction severity. Our results suggest that it could be appropriate to include the time from the last exacerbation in the oxidant-antioxidant balance analysis of COPD patients.

Age-related pattern of the antiepileptic drug utilization in active epilepsy: a population-based survey.

The aim of this study was to investigate the relationship between antiepileptic drug (AED) utilization and patient age in a population of patients treated by primary health care physicians. Data were collected by using questionnaires completed by family physicians and paediatricians working in primary health care. Only patients with active epilepsy confirmed previously by neurologists or neuropaediatricans were included. One hundred and twenty-three physicians provided the requested data for 966 patients (range 1-92 years). Most frequently prescribed AEDs were barbiturates (BARB) (37%) and carbamazepine (CBZ) (37%). Valproic acid derivates (VPA) were prescribed in 28%, but the rate was higher (51%) in children. By calculating the correlation between age and the prescription of single AEDs across the whole sample, linear correlations were found for BARB (r = 0.94; p < 0.01), VPA (r = -0.93; p < 0.01) and for topiramate (TPM) (r = -0.90; p < 0.01). Since our results showed significant correlations between age and the use of the majority of AEDs, we concluded that the age may be considered a methodological bias in the presentation of data. Therefore we calculated AED utilization as the age-adjusted prevalence rates (per/1000 inhabitants). For the most commonly prescribed AEDs they were: BARB 1.8 (95% CI 1.6-2.0), CBZ 1.9 (95% CI 1.7-2.1), VPA 1.3 (95% CI 1.1-1.5), lamotrigine (LTG) 0.7 (CI 95% 0.6-0.8), TPM 0.6 (CI 95% 0.5-0.7). In conclusion, the age of patients has a significant impact on the prescription patterns not only between children and adults, but at every age. Therefore we suggest that reporting of AED utilization pattern should also include age-standardized prevalence rates of individual AED utilization.

Vestibular atelectasis: Decoding pressure and sound-induced nystagmus with bilateral vestibulopathy.

We present the case of a 27-year-old male who presented with vertigo when pressing the entrance of his right auditory meatus and exposing his right ear to loud noise. A diagnostic procedure revealed bilateral labyrinth weakness, which was confirmed by caloric and rotational testing. The ocular vestibular evoked myogenic potentials investigation demonstrated a significant weakness of the right utriculus, whereas the cervical vestibular evoked myogenic potentials were normal, indicating preservation of the saccular response. Radiologic studies did not show evidence of labyrinthine dehiscence. We suspect the newly described association of this clinical syndrome with the previously described histopathology of vestibular atelectasis accounts for these findings. Laryngoscope, 129:1685-1688, 2019.

Effect of vestibular rehabilitation on recovery rate and functioning improvement in patients with chronic unilateral vestibular hypofunction and bilateral vestibular hypofunction.

BACKGROUND: The minimal number of studies have documented the impact of Vestibular rehabilitation (VR) on the recovery rate of patients with Chronic Unilateral Vestibular Hypofunction (CUVH) and Bilateral Vestibular Hypofunction (BVH). OBJECTIVES: The goal of the study was to show and compare the impact of vestibular rehabilitation (VR) in patients with CUVH and BVH. METHODS: We analysed the data of 30 patients with CUVH and 20 with BVH treated with VR. The patients with CUVH during their eight-week treatment were controlled every two weeks, while the patients with BVH were controlled every three months during their one-year treatment; they filled in the DHI and ABC questionnaires every time. RESULTS: In both groups of patients, there was significantly less disablement between the initial and final DHI scores (from 59-20 in CUVH and 74-41 in BVH group). There was a significant increase in the balance confidence between the initial and final ABC Scale in both groups of patients (from 49.5-90% in CUVH and 42-73% in BVH group). CONCLUSIONS: Well-planned and individually adjusted system of vestibular exercises leads to a significant decrease in clinical symptoms and improvement of functioning and confidence in activities in both the CUVH and the BVH patients.

Impaired cerebrovascular reactivity in chronic obstructive pulmonary disease.

Impaired cerebrovascular reactivity (CVR) is associated with stroke. Cerebrovascular diseases are common comorbidity in chronic obstructive pulmonary disease (COPD) patients. The aim of our study was to quantify CVR in the anterior and posterior cerebral circulation during voluntary breath-holding in COPD patients according to airflow limitation severity. In this cross-sectional study, we compared 90 COPD patients without previous cerebrovascular disease and 30 age- and sex-matched healthy volunteers (mean age 67 ± 7.9, 87 males). Using transcranial Doppler ultrasound and breath-holding index (BHI), we analysed baseline mean flow velocities (MFV) and CVR of middle cerebral artery (MCA) and basilar artery (BA). Our results demonstrated that COPD patients had lower baseline MFV of both MCA and BA than controls. COPD patients had significantly lower BHImMCA and BHImBA than controls (0.8 and 0.7 versus 1.24 and 1.07, respectively; p < 0.001). With the severity of airflow obstruction, there were significant declines of BHImMCA and BHImBA in mild (0.94 and 0.83), moderate (0.8 and 0.7) and severe to very severe COPD (0.7 and 0.6), respectively (p < 0.001). For all participants, we found a significant and positive correlation between forced expiratory volume in one second (FEV1) and BHImMCA (Rho = 0.761, p < 0.001) and between FEV1 and BHImBA (Rho = 0.409, p < 0.001). COPD patients have impaired CVR in anterior and posterior cerebral circulation. Impairment of CVR increase with the airflow limitation severity. CVR is an appropriate marker to identify vulnerable COPD subjects at high risk to develop cerebrovascular disease. Prospective studies are needed for further evaluation.

25 (OH) D3 levels, incidence and recurrence of different clinical forms of benig paroxysmal positional vertigo.

INTRODUCTION: Benign paroxysmal positional vertigo is the most common cause of dizziness in the general population. It is a condition with potential impact of reduced levels of vitamin D on its recurrent attacks. OBJECTIVES: The aim of this study was to measure the serum levels of 25-hydroxyvitamin D3 (25-OH D3) in patients with benign paroxysmal positional vertigo and determine whether there is a difference in the serum levels of vitamin D3 between patients with and without recurrence, as well as between the different clinical forms of benign paroxysmal positional vertigo. METHODS: The study included 40 patients who came to the regular medical examination, diagnosed with posterior canal-benign paroxysmal positional vertigo based on the positive Dix-Hallpike's test. All patients underwent Epley manoeuvre after the diagnosis. Patients were classified according to current guidelines for levels of vitamin D3 in the serum in three groups: the deficiency, insufficiency and adequate level. RESULTS: The average serum level of 25-OH D3 among respondents was 20.78ng/mL, indicating a lack or insufficiency of the aforementioned 25-OH D3. According to the levels of 25-OH D3, most patients suffer from deficiency (47.5%). 7 (17.5%) respondents had adequate blood level of 25-OH D3, and 14 (35%) respondents suffer from insufficiency. A significant difference was not found in the serum level of 25-OH D3 between patients with and without benign paroxysmal positional vertigo recurrence. There was a significant difference in the serum levels of 25-OH D3 in comparison to the clinical form of the disease. Lower 25-OH D3 values were found in patients with canalithiasis compared to those with cupulolithiasis. CONCLUSIONS: There were no significant differences in the vitamin D3 serum level in patients with and without recurrence. The study showed a low level of serum vitamin D3 in most patients, indicating the need for supplemental therapy.

Role of Vestibular Evoked Myogenic Potentials as an Indicator of Recovery in Patients with Benign Paroxysmal Positional Vertigo.

Ocular vestibular evoked myogenic potentials (oVEMP) and cervical VEMP (cVEMP) are newer diagnostic methods, which allow an insight into the otolith senses. Our aim was to determine changes in certain parameters of the VEMP wave complex after successfully performed repositioning procedure, as an indicator of the state of recovery in patients with benign paroxysmal positional vertigo (BPPV). This may confirm the theory of otolith returning into the area of otolithic senses. The study included 48 patients with unilateral posterior semicircular canal BPPV. On their first arrival, otoneurological examinations, oVEMP and cVEMP tests were performed. The same were included in follow up check-ups scheduled at seven days and six months after successful implementation of Epley maneuvers. The initial measurement revealed a significantly reduced amplitude of oVEMP on the affected side. On the 7-day measurement, the amplitude increase was observed on the affected side, with significant reduction in the amplitude ratio (p=0.693), which reached statistical significance on the last measurement at 6 months (p=0.006). These findings confirmed the hypothesis of the return of otoconia into the utricular area.