Simultaneous wireless and high-resolution detection of nucleus accumbens shell ethanol concentrations and free motion of rats upon voluntary ethanol intake

Highly sensitive detection of ethanol concentrations in discrete brain regions of rats voluntarily accessing ethanol, with high temporal resolution, would represent a source of greatly desirable data in studies devoted to understanding the kinetics of the neurobiological basis of ethanol's ability to impact behavior. In the present study, we present a series of experiments aiming to validate and apply an original high-tech implantable device, consisting of the coupling, for the first time, of an amperometric biosensor for brain ethanol detection, with a sensor for detecting the microvibrations of the animal. This device allows the real-time comparison between the ethanol intake, its cerebral concentrations, and their effect on the motion when the animal is in the condition of voluntary drinking. To this end, we assessed in vitro the efficiency of three different biosensor designs loading diverse alcohol oxidase enzymes (AOx) obtained from three different AOx-donor strains: Hansenula polymorpha, Candida boidinii, and Pichia pastoris. In vitro data disclosed that the devices loading H. polymorpha and C. boidinii were similarly efficient (respectively, linear region slope [LRS]: 1.98 ± 0.07 and 1.38 ± 0.04 nA/mM) but significantly less than the P. pastoris-loaded one (LRS: 7.57 ± 0.12 nA/mM). The in vivo results indicate that this last biosensor design detected the rise of ethanol in the nucleus accumbens shell (AcbSh) after 15 minutes of voluntary 10% ethanol solution intake. At the same time, the microvibration sensor detected a significant increase in the rat's motion signal. Notably, both the biosensor and microvibration sensor described similar and parallel time-dependent U-shaped curves, thus providing a highly sensitive and time-locked high-resolution detection of the neurochemical and behavioral kinetics upon voluntary ethanol intake. The results overall indicate that such a dual telemetry unit represents a powerful device which, implanted in different brain areas, may boost further investigations on the neurobiological mechanisms that underlie ethanol-induced motor activity and reward.

Bilateral congenital cholesteatoma: report of an emblematic case

OBJECTIVES

To describe a case of bilateral congenital cholesteatoma (CC) of the middle ear with a focus on diagnostic clues, treatment and a review of the pertinent literature.

PATIENT AND METHODS

An 8-year-old child was incidentally noted to have whitish bilateral retrotympanic masses with normal hearing and referred to our department in January 2005. Microscopic examination of the ears and CT scan of the temporal bones led to a presumptive diagnosis of bilateral CC. The lesion on the right side was surgically removed, followed by that on the left side after 6 months; a retroauricular transcanal approach was adopted in both ears.

RESULTS

Anatomic integrity of the middle ear was achieved with preservation of pre-operative hearing. No signs of recurrence were evident 20 months after the last surgery.

CONCLUSIONS

Bilateral CC is a rare finding but otologists must be aware of it. Surgery must be planned early in order to achieve radical removal of the pathology and the preservation of middle ear structures.

Paget’s disease and cochlear implantation

Paget’s disease of bone is a common disorder of unresolved etiology characterized by excessive bone resorption followed by excessive bone formation. If the skull isaffected this may result in hearing loss and eventually develop into profound deafness. To date, no cases of cochlear implantation in patients with Paget’s disease have been reported.

The authors present a case of radiographically confirmed Paget’s disease of the skull in a 77-year-old man with a 20-year history of progressive bilateral sensorineural hearing losswho underwent cochlear implantation. A successful insertion of the Nucleus 24 Contour electrodearray was achieved without surgical and postoperative complications.

At the 10 months’ postoperative evaluation, the patient had gained useful open-set speech perception. In quiet conditions, his performance scores on the word and sentence recognition tests were 100 and 98 per cent, respectively. In the presence of noise (at +10 dB. signal-to-noise ratio), his performance scores on the word and sentence recognition tests were 96 and 94per cent, respectively.

Effects of gastroesophageal reflux disease in laryngeal carcinoma

Gastroesophageal reflux disease is associated with various otolaryngological disorders. The aim of this retrospective study was to determine the role of gastroesophageal reflux disease in the development of laryngeal squamous cell carcinoma (SCC) in non-smoking and non-drinking patients. The study population consisted of 36 consecutive non-smoking and non-drinking patients with histologically confirmed SCC of the larynx. As a control, a group of 125 lifetime non-smoking and non-drinking cancer-free subjects were selected. Patients with laryngeal cancer had a higher prevalence of gastroesophageal reflux disease than the control subjects (P < 0.0001). Our results confirm the fact that gastroesophageal reflux disease in itself is associated with an increased risk of laryngeal cancer.

Effects of gastroesophageal reflux disease in laryngeal carcinoma

Gastroesophageal reflux disease is associated with various otolaryngological disorders. The aim of this retrospective study was to determine the role of gastroesophageal reflux disease in the development of laryngeal squamous cell carcinoma (SCC) in non-smoking and non-drinking patients. The study population consisted of 36 consecutive non-smoking and non-drinking patients with histologically confirmed SCC of the larynx. As a control, a group of 125 lifetime non-smoking and non-drinking cancer-free subjects were selected. Patients with laryngeal cancer had a higher prevalence of gastroesophageal reflux disease than the control subjects (P < 0.0001). Our results confirm the fact that gastroesophageal reflux disease in itself is associated with an increased risk of laryngeal cancer.

Salvage surgery after radiation failure in squamous cell carcinoma of the larynx

AIM AND BACKGROUND

To investigate patients treated with radiotherapy (RT) for laryngeal squamous cell carcinoma (SCC) in order to estimate the recurrence rate and treatment used as salvage surgery. The survival rate in the group of patients treated with salvage surgery was compared to that of patients who had chemotherapy rather than surgery or who refused any treatment.

METHODS

From 1989 to 1999, 185 patients came to our institution for laryngeal SCC. All of them underwent RT as primary treatment. Only patients with a minimum of three years follow-up (n = 143) were included in the study group.

RESULTS

The 143 cases included 22 loco-regional recurrences (15.3%) during the minimum three years of follow-up. Recurrence was observed in the larynx in eighteen cases (81.8%), in cervical nodes in one case (4.55%) and in both the larynx and cervical nodes in one case (4.55%). There was peristomal recurrence in two cases (9.1%). Recurrence was observed after an average of 16.3 months. Fourteen patients (63.6%) out of the twenty-two cases of recurrence underwent salvage surgery. Surgery was not performed on the remaining eight patients (36.4%). The global survival rate was 92.3% after three years and 66.6% after five years in the group of patients treated with surgery. The actuarial survival rate was 100% after three years and 83.3% after five years. The global and actuarial survival rate was 20% after three years and 0% after five years in the group of patients who received chemotherapy rather than surgery or who refused any kind of treatment.

CONCLUSION

The RT seems to play an important role in the loco-regional control of laryngeal SCC (especially in glottic T1). Salvage surgery for recurrence results in a good survival rate.

Gastroesophageal reflux as a possible co-promoting factor in the development of the squamous-cell carcinoma of the oral cavity, of the larynx and of the pharynx

According to recent advances it is assumed that the gastroesophageal reflux (GER) is a possible co-promoting factor of the squamous-cell carcinoma development in the upper parts of the gastro-intestinal and respiratory systems, considering the higher frequency of lesions due to acid in the studied population interested by GER. The aim of this study is to investigate 274 patients with malignant neoplasm of the oral cavity, of the pharynx and of the larynx, by esophago-gastro-duodenoscopy (EGD) and to compare the incidence of GER in this group with a control group of healthy patients from their hospital. Acid exposure in the upper level of the esophagus often remains unknown using traditional pH-monitoring, especially if no pharyngeal probe is used. When necessary a good diagnostic test is EGD with mucosa biopsy; it allows to directly examine the lesion. We retrospectively studied the data of 274 patients suffering from a cancer of the upper aero-digestive tracts by EGD in order to diagnose lesions caused by GER. We compared non-smoking patients affected by GER and tumours a control group of healthy patients. Statistical analysis revealed a significant difference between the two groups using the z-Test (p = 0.0001). In our study, based on endoscopic data, we observed a high percentage of non-smoking patients affected by GER and squamous-cell carcinoma of the upper parts of the airways and the gastrointestinal system. For this reason we consider GER as a possible co-promoting factor of cancer in some patients.

Speech recognition in elderly cochlear implant recipients

The benefits of cochlear implantation in the adult and paediatric populations are well established. Cochlear implantation in the geriatric population still remains controversial because of the misconception that elderly patients might perform poorly. The purpose of this study was to report the speech performance of 16 patients over 65 years of age implanted with a Nucleus multichannel cochlear implant and to compare it with that of a control group of 14 adults aged between 41 and 59 years. At the 12 months postoperative evaluation, no significant differences were detected on speech performances between the elderly patients and the control group. The mean word recognition scores were 72.5% for the elderly group and 82% for the control group. The mean everyday sentence recognition scores were 72.5% for the elderly group and 85.7% for the control group. Overall, the results are encouraging and demonstrate that the elderly population with profound hearing loss obtain significant benefits from cochlear implantation despite the age-related auditory processing problems.

[Multi-channel cochlear implant in cochlear ossification]

Cochlear ossification, considered until only a few years ago as a contraindication for cochlear implants (C.I.), may now be managed by means of a wide variety of surgical techniques. In cases with massive ossification, the drill-out circummodiolar technique described by Gantz et al. in 1988 and successively modified by Balkany et al. in 1997 may be adopted. The technique of electrode insertion in the scala vestibuli, perfected by Steenerson et al. in 1990, may be used when cochlear ossification has spread no further than the scala tympani. Other methods call for a groove to be drilled along the proximal tip of the basal turn of the cochlea (Cohen and Waltzman, 1993), the insertion of electrodes through the middle cranial fossa (Colletti et al., 2000), or the utilization of a double electrode array (Bredberg et al., 1997, Lenarz et al., 2001). This study reports the experience conducted at the Cochlear Implants Centre of the Otorhinolaryngoiatrics, Otological and Otoneurological Microsurgery Section of the University of Parma in a group of 15 patients who underwent C.I. in the presence of varying degrees of ossification. In 3 cases the ossification was limited to the region of the round window and a few millimetres of the scala tympani; cochleostomy was performed anteriorly and inferiorly to the anterior niche of the round window. In 11 cases (of which 3 of pediatric age), the ossification had spread to the horizontal portion of the scala tympani; in these cases, the electrodes were inserted in the scala vestibuli. The scala vestibuli was opened by drilling anteriorly to the round window and superiorly to the spiral ligament. In the only case of massively ossified cochlea, it was possible to partially insert the electrodes in a circum-modiolar tunnel. In the 12-month follow-up hearing test, the 3 patients with ossification of the round window region and the first millimetres of the scala tympani respectively averaged 61.6% in recognizing 2-syllable words and 59% in recognizing words embedded in phrases. The averages on the 12-month follow-up hearing test in the 8 adult patients who received the implant in the scala vestibuli were 80.6% in recognizing 2-syllable words and 89.1% in recognizing words in phrases. The 3 pediatric patients were classified on the Geers and Moog scale, which situated 2 of them in the 6th category of perception and 1 of them in the 4th category of perception. As regards the only case of massive cochlear ossification, the patient underwent surgery recently, and the sole follow-up available is the one conducted after only 3 months; the vowel identification average was 55%; the average on the VCV test was 31%; and the 2-syllable word recognition average was 20%.

Congenital cholesteatoma of the tympanic membrane

We present two cases of congenital cholesteatoma of the tympanic membrane. Congenital cholesteatoma within the tympanic membrane is a rare entity with only few cases documented. The aetiopathogenesis of this lesion is still unknown. An embryologic origin is hypothesized when cholesteatoma develops in patients without previous history of otitis as in the two cases we report. In cases with previous history of inflammatory process of the external or middle ear an acquired origin is suspected due to the proliferation of the basal cell layer of the tympanic membrane epithelium. Despite the rarity of the congenital tympanic membrane cholesteatoma, we think that its early diagnosis is of utmost importance to allow an easy removal and avoid middle ear involvement.

The pectoralis major myocutaneous flap in head and neck reconstructive surgery: 16 years of experience

Wide defects resulting after resection of malignant tumors of the head and neck need an adeguate closure. In the last 16 years, 85 pectoralis major myocutaneous island flap procedures were carried out for the immediate reconstruction of surgical defects following extirpation of malignant tumors at various sites of the upper aerodigestive tract. The final functional and cosmetic results were satisfactory. Partial necrosis was observed in four cases. We did not have any cases of total flap necrosis. Post-operative fistulas were encountered in 14 cases (surgical closure was not necessary). The application and complications of the pectoralis major myocutaneous flap placed at cervical level are reviewed. The aspects of postoperative swallowing function of such surgery are discussed. Reconstruction with the pectoralis major myocutaneous flap is a safe and versatile procedure, yielding good clinical and functional results in patients with advanced head and neck tumors.

[Brainstem auditory evoked potentials in neonatology: the method and results in a group of normal newborns]

Brainstem evoked responses audiometry was performed on 10 newborn infants. They ranged in postnatal age from 19 hours to 5 days and in estimated gestational age from 39 to 42 weeks. Clicks of 0.1 msec duration were presented at a rate of 11.4 per second. Measurements were made at 50, 80 and 100 dB. Wave V latencies were evaluated at 50, 80 and 100 dB HL in order to measure the auditory threshold. The latency of wave V is the datum of interest. Wave V responses were obtained bilaterally at 50 dB HL. Waves I and III latencies were measured at 100 dB HL.

[Intraoperative tonal-threshold audiometry in the surgery of otosclerosis]

At the end of stapedioplasty, performed under local anesthesia, the surgeon usually tests the hearing function making questions to the patient turning his voice from a soft whisper to a loud tone. At the ENT Department, University of Parma Italy, a more precise method is employed in order to measure the air conduction threshold of the patient at the beginning and at the end of surgery. From April 1996 to October 1996, intraoperative pure-tone audiometry was performed in 36 patients who underwent stapedioplasty. A portable audiometer "Amplaid 161/C Amplifon" was used in the operating room. Air conduction thresholds were measured at 125-8000 Hz. Intraoperative pure-tone audiometry allows an instantaneous and a more accurate evaluation of the surgical functional results.

[Electrocochleography by extra- and transtympanic methods: the results in a group of normal subjects]

Electrocochleography (ECoG) is an electrophysiologic approach to the study of hearing. In ECoG, electrical activity that originates within the cochlea or the auditory nerve is recorded. ECoG represents an evoked or stimulus dependent measure. The electrical potentials which can be analyzed in ECoG are: the cochlear microphonic potential (CM), the summating potential (SP) and the acoustic nerve potential (AP). Two major types of electrocochleography electrodes can be used, transtympanic and extratympanic. Transtympanic ECoG is performed by inserting a long needle electrode, placed through the tympanic membrane onto the promontory. Extratympanic ECoG is recorded by using electrodes placed within the external meatus near the tympanic membrane. At the ENT Department of the University of Parma, ECoG was performed in 10 normal hearing subjects (4 males and 6 females. Their ages ranged from 21 to 29 years (mean 26 years). All subjects underwent ECoG recording simultaneously with extratympanic and transtympanic technique.

Craniofacial fibrous dysplasia associated with primary hyperparathyroidism

Isolated presentation of fibrous dysplasia or primary hyperparathyroidism is a common finding. Only few cases of craniofacial dysplasia associated with hyperparathyroidism have been reported in the literature. A case of a patient with fibrous dysplasia of craniofacial bones associated with primary hyperparathyroidism without additional endocrinophaties or associated disorders, will be presented. Beside the facial dysmorphism caused by dysplasia, the only clinical symptoms were due to the primary hyperparathyroidism.

[Progressive sensorineural hearing loss: neoplastic causes]

Acoustic neuromas represent about 90% of all space-occupying lesions of the cerebellopontine angle and account for approximately 6% of all intracranial tumors. Progressive unilateral sensorineural hearing loss is the most frequent initial symptom occurring in over 90% of patients. A sudden onset of hearing loss occurs in 5%, while 5% of cases present with normal hearing. The incidence of hearing loss does not seem to be related to tumor size. Accuracy of the tumor detection by gadolinium-enhanced magnetic resonance imaging has been reported as 99-100% even for intracanalicular tumors. The ABR false negative rate for intracanalicular tumors has been reported to be as high as 9-11%. Rare lesions of the cerebellopontine angle include: meningiomas, epidermoids, arachnoid cysts, trigeminal nerve neuromas, facial nerve neuromas, neurinomas of lower cranial nerves, glomus tumors and metastases. Therefore, a high suspicion index and awareness of symptoms and an adequate audiologic and neuroradiologic work-up are the clues to early diagnosis and appropriate surgical treatment.

Scutumplasty: costal cartilage versus bone paté

This study was carried out to evaluate the anatomical and hearing results of the reparation of attic defects in closed tympanoplasty. Reparation was carried out in 194 patients by using a costal cartilage allograft, and in 159 patients with a bone pate autograft. The follow-up was from 1 to 5 years. The study was not truly randomized owing to an occasional lack of allogenic costal cartilage. In the group 'costal cartilage' a partial resorption was observed in 5.7% and a complete resorption in 4.7% of the cases. In the group 'bone pate', partial resorption was observed in 5.5% and total resorption in 2.7% of the patients. Satisfactory hearing results were obtained in 86% of the patients of the group 'costal cartilage' and in 82% of the patients of the group 'bone paté'. Both graft materials may be recommended for repairing erosions caused by the cholesteatoma in the wall of the external auditory canal.