Petrous bone cholesteatoma

Petrous bone cholesteatoma is a rare pathologic entity and may be a difficult surgical challenge because of potential involvement of the facial nerve, carotid artery, dura mater, otic capsule, and risk of cerebrospinal fluid leak. The objective of this article is to present a personal classification of petrous bone cholesteatomas, a survey of recent surgical attitudes, and our present surgical strategy based on our experience with 54 operations between 1978 and 1990. Radical petromastoid exenteration with marsupialization and the middle cranial fossa approach were used only for small pure infra- or supralabyrinthine cholesteatomas, respectively. The enlarged transcochlear approach with closure of the external auditory canal was used for infralabyrinthine, infralabyrinthine-apical, and massive petrous bone cholesteatomas. Five cases with petrous bone cholesteatomas in different locations are described in detail to present the signs and symptoms together with the management.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Mastoidectomy in noncholesteatomatous chronic suppurative otitis media: is it necessary?

Chronic suppurative otitis media (CSOM) without cholesteatoma, the surgical treatment of which is still controversial, is a common diagnosis in otologic practice. A retrospective analysis of 323 patients who underwent surgery for noncholesteatomatous chronic otitis media in the Gruppo Otologica, Piacenza, Italy, between April 1983 and December 1993 is presented. Cases were separated into three groups according to different surgical treatment modalities and conditions of the ears at the time of operation. Group I (n = 53) consisted of cases of CSOM treated by tympanoplasty without mastoidectomy (TLWOM). Group II (n = 28) included cases of CSOM treated by tympanoplasty with mastoidectomy (TLWM). Intact canal wall technique was used in these cases. The ears in both these groups were discharging severely at the time of surgery. Group III (n = 242) included patients whose ears were dry at the time of surgery but who had had previous recurrent episodes of suppuration and who were treated by TLWOM. At the last follow-up, graft success rates for groups I, II, and III were 90.5%, 85.7%, and 89.2%, respectively, and mean residual gaps were 17.2 dB, 20.1 dB, and 19.4 dB, respectively. There was no statistically significant difference between the three groups either on graft success rates (p > 0.05) or on final functional hearing outcome (p > 0.05). TLWM is the preferable treatment modality for most surgeons in noncholesteatomatous CSOM. Nevertheless, in our experience TLWOM yields comparable results for this group of patients. In addition, we could not find any significant difference in results of graft success and final functional hearing rates between dry and discharging ears (p > 0.05).

Lavender (Lavandula angustifolia Mill.) Essential Oil Alleviates Neuropathic Pain in Mice With Spared Nerve Injury

Low treatment efficacy represents an important unmet need in neuropathic pain patients and there is an urgent need to develop a more effective pharmacotherapy. An increasing number of patients choose complementary medicine to relieve pain. Lavender essential oil (LEO) is approved by the European Medicines Agency as herbal medicine to relieve anxiety and stress. However, the capability of LEO to relieve other nervous system disorders such as neuropathic pain has never been established. Our work aimed to evaluate the antineuropathic properties of lavender on a spared nerve injury (SNI) model of neuropathic pain in mice. An acute oral administration of LEO (100 mg/kg) alleviated SNI-induced mechanical allodynia, evaluated in the von Frey test, with an intensity comparable to the reference drug pregabalin. Investigations into the mechanism of action showed that LEO markedly decreased the phosphorylation of ERK1, ERK2, and JNK1, and decreased the levels of iNOS in the spinal cord; involvement of the endocannabinoid system was also detected using in vitro inhibition of the FAAH and MALG enzymes as well as in vivo experiments with the CB1 antagonist. Conversely, no effect on P38 phosphorylation and NF-kB activation was detected. These antihyperalgesic effects appeared at the same dose able to induce antidepressant-like, anxiolytic-like, and anorexic effects. In addition, gavage with LEO did not significantly alter animals' gross behavior, motor coordination, or locomotor activity, nor impaired memory functions. Oral administration of LEO could represent a therapeutic approach in the management of neuropathic pain states.

Cholesteatoma surgery: the individualized technique

A retrospective analysis of 433 cholesteatoma cases, surgically treated at the Gruppo Otologico, Piacenza, Italy, over a 7-year period, is reported. The purpose of this study was to delineate actual indications for individualizing open and closed procedures and to compare their results as regards residual or recurrent disease and hearing. The total incidences of residual and recurrent cholesteatoma in the open cavity procedures were 10% and 2.38%, respectively, while the closed procedures showed higher incidences of residual and recurrent cholesteatoma: 31.22% and 11.16%, respectively. The problem of a persistently discharging cavity was encountered in only 1 case of an open procedure, while 2 patients had persistent otorrhea among the closed cavity cases. The hearing results, although slightly better in the closed procedures, were not significantly different from those in the open procedures.

Meningoencephalic herniation into the middle ear: a report of 27 cases

Meningoencephalic herniation into the middle ear is a rare and potentially life-threatening condition that may require prompt surgical intervention. Preoperative diagnosis is based on a high index of suspicion. Sometimes, however, meningoencephalic herniation is discovered during surgery. High-resolution computed tomography and magnetic resonance imaging should be performed to confirm the diagnosis and to evaluate the extension of the herniated tissue. This article discusses the diagnostic approach, management strategy, and surgical technique used in 27 patients with meningoencephalic herniation. In an attempt to avoid infective complications, the authors used the middle cranial approach in patients with large herniations.

The HDAC1/c-JUN complex is essential in the promotion of nerve injury-induced neuropathic pain through JNK signaling

Histone deacetylase inhibitors (HDACIs) interfere with the epigenetic process of histone acetylation and are known to have analgesic properties in models of chronic inflammatory pain. Administration of a selective HDAC1 inhibitor (LG325) in SNI-subjected mice significantly attenuated behavior related to injury-induced pain. Understanding the HDAC1 pathway in epigenetic regulation of pathological pain is of great medical relevance. Spared nerve injury (SNI) mice showed a significant increase in the HDAC1 protein levels within spinal cord in coincidence with the nociceptive phenotype at 1 and 3 weeks after nerve injury. No variation in HDAC3, DNMT3a, AcH3, MBD3 and MeCP2 levels was detected. Increased expression of HDAC1 is accompanied by activation of the JNK-c-Jun signaling pathway. A robust spinal JNK-1 overphosphorylation was observed post nerve-injury along with a selective JNK-dependent increase in p-c-Jun and HDAC1 protein levels. Co-immunoprecipitation experiments showed the presence of a heterodimeric complex between HDAC1 and c-Jun in SNI mice indicating that these transcription factors can act together to regulate transcription through heterodimerization. Stimulation of c-Jun phosphorylation was prevented by the selective HDAC1 inhibitor LG325. We found that HDAC1 was associated with c-Jun in nuclei of spinal dorsal horn astrocytes expressing JNK. On the other hand, the presence of HDAC1 and c-Jun interaction was not detected in control mice. These findings provide new insights into the mechanisms underlying the anti-nociceptive activity of HDAC inhibitors. Taken together, these data support a role for histone deacetylase in the emergence of neuropathic pain.

Lower cranial nerve schwannomas involving the jugular foramen

Schwannomas involving the jugular foramen are rare lesions, and no consensus exists on their management. This paper reports on 20 such cases treated in our centers. Nineteen cases were operated on for removal of the tumors, and the remaining case is being managed by watchful expectancy. Fifteen cases were operated on by the petro-occipital trans-sigmoid approach with or without labyrinthectomy, 2 by the infratemporal fossa approach, 1 by the modified transcochlear approach, and 1 by the jugulo-petrosectomy approach. The petro-occipital trans-sigmoid approach allowed single-stage, total tumor removal with preservation of the facial nerve and of middle and inner ear functions. Lower cranial nerve paralysis was the major complication and seemed to be inherent to the disease rather than to the approach used. No cerebrospinal fluid leak or meningitis occurred in the present series. So far, no recurrence has been detected.

Lateral approaches to the median skull base through the petrous bone: the system of the modified transcochlear approach

Twenty-three patients with intradural lesions of the petroclival region and prepontine cistern were managed in our centres by the modified transcochlear approach. Total tumour removal was accomplished in 17 patients, while a second stage was planned for the remaining six patients. Two cases died in the immediate post-operative period. All the remaining cases showed a good outcome and returned to work. The basic approach type A is further classified according to its anterior, superior and inferior extension into types B, C and D respectively. The surgical procedure, classification, illustrative case reports and patients' summaries are presented.

Pleiotropic effect of histamine H4 receptor modulation in the central nervous system

The histamine H4 receptor (H4R) is expressed primarily on cells involved in inflammation and immune responses. Recently, it has been reported the functional expression of H4R within neurons of the central nervous system, but their role has been poorly understood. The present study aimed to elucidate the physiopathological role of cerebral H4R in animal models by the intracerebroventricular administration of the H4R agonist VUF 8430 (20-40 μg per mouse). Selectivity of results was confirmed by the prevention of the effects produced by the H4R antagonist JNJ 10191584 (3-9 mg/kg p.o.). Neuronal H4R activation induced acute thermal antinociception, indicating that neuronal histamine H4R might be involved in the production of antinociception in the absence of an inflammatory process. An anxiolytic-like effect of intensity comparable to that exerted by diazepam, used as reference drug, was produced in the light-dark box test. VUF 8430 reversed the scopolamine-induced amnesia in the passive avoidance test and showed anorexant activity in food deprived mice. Conversely, the H4R activation did not modify the immobility time in the tail suspension test. Rotarod performance test was employed to demonstrate that the effects observed following the administration of VUF 8430 and JNJ 10191584 were not due to impaired motor function of animals. Furthermore, both compounds did not alter spontaneous mobility and exploratory activity in the hole board test. These results show the antinociceptive, antiamnesic, anxiolytic and anorexant effects induced by neuronal H4R agonism, suggesting that H4 modulators may have broader utility further the control of inflammatory and immune processes.

Lower skull base: anatomic study with surgical implications

With advances in the lateral approaches to the skull base and the increasing success of the management of jugular foramen lesions, a thorough knowledge of the anatomy of this region is needed. The purpose of the present work is to study the detailed microsurgical anatomy of the lower skull base and the jugular foramen area as seen through the lateral approaches. Forty preserved skull base specimens and 5 fresh cadavers were dissected. The shape of the jugular bulb and its relationship to nearby structures were recorded. The different venous connections of the bulb were noted. The hypoglossal canal was identified and its contents were observed. The lower cranial nerves were studied at the level of the upper neck, at their exit from the inferior skull base, and in the jugular foramen. The results of the present study showed the complex and variable anatomy of this area. The classic compartments of the jugular foramen were not always present. Cranial nerves IX through XI followed different patterns while passing through the jugular foramen, being separated from the jugular bulb by bone, thick fibrous tissue, or thin connective tissue.

The surgical management of childhood cholesteatoma

The results of treatment of 124 cases of childhood cholesteatoma are reported in the present study and compared with an adult group of patients. Intact canal wall tympanoplasty was performed in over 90 per cent of cases in children and the procedure was staged in nearly 80 per cent of cases. The children had a 43.8 per cent incidence of residual cholesteatoma and an 8.8 per cent incidence of recurrent cholesteatoma in intact canal wall tympanoplasty cases. Intact canal wall tympanoplasty remains the technique of choice in our hands for the treatment of childhood cholesteatoma; pre-planned staging of the operation is mandatory for the detection and elimination of residual cholesteatoma which occurs more frequently in children.

Hearing preservation in vestibular schwannoma surgery: fact or fantasy?

This study reviews 57 papers dealing with the issue of hearing preservation in vestibular schwannoma surgery published in otolaryngologic and neurosurgical literature between the years 1977 and 1994. The authors', in this review, have made an attempt to verify whether the claims of hearing preservation are real, whether there is a price to be paid in terms of morbidity and whether there are univocal criteria for reporting results. The review shows that there is a wide disarray in reporting hearing results and the claims of hearing preservation are often unreal and misleading. On retabulating the results of a few series according to the minimal prerequisites for normal hearing (PTA < or = 30 dB and SDS > or = 70 per cent) and according to other various commonly reported criteria, it became evident that rates of hearing preservation differed a lot depending upon criteria. While any measurable hearing could be preserved in many cases, only a few had normal hearing preserved.

Degenerative changes in the distal stump of the severed human facial nerve

Specimens of distal segments of the human facial nerve obtained at reinnervation surgery (hypoglossal-facial anastomosis) were studied by light and electron microscopy. Severance of the facial nerve led to the Wallerian degeneration in the distal segment. When the lesion was made at the intracranial level of the nerve, the sensory bundle remained intact. In a specimen 17 days after section, motor fibers either had disappeared or had loss of axons and advanced stage of myelin breakdown. Sensory fibers appeared intact. In two specimens three months after severance, many Schwann cells of degenerated fibers still possessed degraded myelin; most Schwann cells had ingested myelin and formed endoneurial tubes (bands of Büngner). Endoneurium showed proliferation of fibroblasts and increased collagen deposition. A specimen obtained seven months after section showed fibrosis only. The fifth specimen obtained 30 months after severance of the tympanic segment showed only mild collagenization and well formed, not appreciably shrunken Schwann tubes. The distal stump of human facial nerve appears to undergo less denervation atrophy than demonstrated in the peripheral nerves of experimental animals. The collagenization process appears to be essentially completed already after three months denervation with little change after that. The distal stump of the human facial nerve appears to provide a good structural basis for reinnervation even after prolonged denervation.

The retroangular flap for nasal reconstruction

Many techniques can be used for nasal reconstruction. This paper describes the preliminary results of our study and shows a one-stage method for partial nasal reconstruction performed with a fasciocutaneous island flap with a retrograde blood supply based on the angular artery. This flap is called the retroangular flap. Six patients had been treated from January of 1993 to January of 1994. The technique is illustrated, and the correlated complications and results are also shown. The flap's color and texture have always been satisfactory. In one patient, the thickness of the flap required a secondary defatting. No sequelae were observed in the donor site.

Surgical treatment of cholesteatoma in children

Treating cholesteatoma in children is still controversial. This article reviews 93 cases of pediatric cholesteatoma operated on from 1983 to 1991 in the Gruppo Otologico, Placenza, Italy, and details the results in 83 children who underwent the intact canal wall technique. During second-stage surgery, residual cholesteatoma was detected in 38% of patients. Recurrent cholesteatoma was detected in 10% of patients treated with the intact canal wall technique. Residual cholesteatoma was seen in the middle ear cleft in 63%, in the epitympanum in 26%, and in the mastoid in 11% of cases. Social hearing level (< 25 dB) was achieved in 85% of cases with suprastructure, whereas only 53% of patients without suprastructure had these levels. In the treatment of cholesteatoma in children by use of the intact canal wall technique, a preplanned second-look operation is mandatory to eradicate the disease.

Electromyographic evaluation of facial nerve damage in acoustic neuroma surgery

OBJECTIVE

This study aimed to determine whether postoperative facial nerve paralysis or surgical manipulation causing paralysis could be predicted on train responses during intraoperative facial nerve monitoring in acoustic neuroma surgery.

STUDY DESIGN AND SETTING

This was a prospective study performed at a tertiary referral center.

PATIENTS AND METHODS

Train responses were recorded on a floppy disk and compared with postoperative facial nerve function in 51 patients who underwent enlarged translabyrinthine acoustic neuroma surgery.

MAIN OUTCOME MEASURES

The number, duration, frequency, and peak-to-peak amplitude of train responses were analyzed and compared with postoperative facial nerve function.

RESULTS

Trains were observed in 42 of 51 patients. Six of seven patients with high-amplitude trains more than 250 microV, and three of five patients with bomber-type high-frequency trains elicited during tumor dissection from the facial nerve or stretching the nerve, showed severe facial nerve dysfunction. On the other hand, seven of the nine patients with no trains also showed severe facial nerve dysfunction.

CONCLUSIONS

The presence of high-amplitude or high-frequency trains elicited by surgical manipulation to the facial nerve seems to indicate a critical situation for the facial nerve. However, certain types of mechanical trauma resulting in severe facial nerve paralysis cannot be identified by train responses.

Histamine H4 receptor agonist-induced relief from painful peripheral neuropathy is mediated by inhibition of spinal neuroinflammation and oxidative stress

BACKGROUND AND PURPOSE

Neuropathic pain is under-treated, with a detrimental effect on quality of life, partly because of low treatment efficacy, but also because pathophysiological mechanisms are not fully elucidated. To clarify the pathobiology of neuropathic pain, we studied the contribution of neuroinflammation and oxidative stress in a model of peripheral neuropathy. We also assessed an innovative treatment for neuropathic pain by investigating the effects of histamine H₄ receptor ligands in this model.

EXPERIMENTAL APPROACH

A peripheral mononeuropathy was induced in mice, by spared nerve injury (SNI). Neuroinflammation and oxidative stress parameters were evaluated by spectrophotometry. The mechanical (von Frey test) and thermal (plantar test) nociceptive thresholds were evaluated.

KEY RESULTS

SNI mice showed increased expression of the pro-inflammatory cytokines IL-1ß and TNF-α, decreased antioxidant enzyme Mn-containing SOD (MnSOD), increased levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an indicator of oxidative DNA damage, and of PARP, nuclear enzyme activated upon DNA damage. Intrathecal administration of VUF 8430 (H₄ receptor agonist) reversed the mechanical and thermal allodynia and was associated with decreased expression of IL-1ß, TNF-α, 8-OHdG and PARP and with restoration of MnSOD activity in the spinal cord and sciatic nerve. These effects were prevented by JNJ 10191584 (H₄ receptor antagonist).

CONCLUSION AND IMPLICATIONS

In the SNI mouse model of neuropathic pain, neuronal H₄ receptor stimulation counteracts hyperalgesia and reduces neuroinflammation and oxidative stress in the spinal cord and sciatic nerve. Targeting both oxidative stress and pro-neuroinflammatory pathways through H₄ receptor-mediated mechanisms could have promising therapeutic potential for neuropathic pain management.

Management of the high jugular bulb in the translabyrinthine approach

A high jugular bulb is a frequent problem in the translabyrinthine approach. This article described a safe technique for effective inferior displacement of the high bulb.

Cerebrospinal fluid leak after translabyrinthine acoustic neuroma surgery

Cerebrospinal fluid leakage is the most common complication of translabyrinthine acoustic neuroma surgery. This retrospective study reviews patients who had translabyrinthine acoustic neuroma surgery at the Gruppo Otologico, Piacenza, Italy, and ENT Department of Bergamo General Hospital, Bergamo, Italy, during the last 6 years. The incidence of postoperative cerebrospinal fluid leakage was 6.2%, and 75% of these patients underwent another surgery to control the cerebrospinal fluid leakage. A modification of translabyrinthine approach was used in patients with highly pneumatized temporal bones to prevent cerebrospinal fluid leakage in these high-risk patients.

Impact of cholesterol lowering treatment on plasma kynurenine and tryptophan concentrations in chronic kidney disease: relationship with oxidative stress improvement

BACKGROUND AND AIM

Tryptophan (Trp) degradation via indoleamine (2,3)-dioxygenase (IDO), with consequent increased in kynurenine (Kyn) concentrations, has been proposed as marker of immune system activation. Oxidative stress (OS) might contribute to the pro-inflammatory state in chronic kidney disease (CKD) through the activation of NF-kB, with consequent activation and recruitment of immune cells.

METHODS AND RESULTS

Serum concentrations of Trp and Kyn, oxidative stress indices malondialdehyde (MDA) and allantoin/uric acid (All/UA) ratio and anti-oxidant amino acid taurine were measured in 30 CKD patients randomized to 40 mg/day simvastatin (group 1), ezetimibe/simvastatin 10/20 mg/day (group 2) or ezetimibe/simvastatin 10/40 mg/day (group 3) and treated for 12 months. Baseline Kyn and Kyn/Trp ratio were higher in CKD patients vs. healthy controls (1.67 ± 0.62 μmol/L vs 1.25 ± 0.40 μmol/L, p < 0.01 and 0.036 ± 0.016 vs 0.023 ± 0.010, p < 0.001 respectively). Both Kyn and Kyn/Trp ratio significantly decreased after cholesterol lowering treatment, to values comparable with healthy controls after one year treatment (1.67 ± 0.62 μmol/L vs 1.31 ± 0.51 μmol/L, p < 0.0001 and 0.036 ± 0.016 vs 0.028 ± 0.012 p < 0.0001, respectively). This was paralleled by a significant decrease in MDA (218 ± 143 nmol/L vs 176 ± 123 nmol/L, p < 0.01) and All/UA ratio (1.47 ± 0.72 vs 1.19 ± 0.51, p < 0.01) in CKD patients.

CONCLUSIONS

Amelioration of both oxidative and inflammation status after cholesterol lowering treatment in CKD might be mediated by restoration of antioxidant taurine concentrations during therapy (from 51.1 ± 13.3 μmol/L at baseline to 63.1 ± 16.4 μmol/L, p < 0.001 by ANOVA), suggesting that improvement of both oxidative and inflammation status in CKD patients could be explained, at least partly, by the cholesterol lowering effects.

A posterolateral approach to the skull base: the petro-occipital transsigmoid approach

This posterolateral approach is directed to the petro-occipital skull base and is a combination of a suboccipital craniotomy, with an inferoposterior petrosectomy. The areas exposed are the jugular foramen, occipital condyle, lower clivus to the midline, petrous apex, tympanic cavity, the vertical portion of the intrapetrous carotid artery below the level of the eustachian tube, cerebellopontine angle, the jugulocarotid space in the upper neck. We evaluated 45 cases as follows: 13 chemodectomas, 14 lower cranial nerve schwannomas, 10 meningiomas, and 8 other lesions. The approach is indicated for extra-, intra-, and transdural lesions of the jugular foramen area. The transdural lesions could be extirpated in a single procedure without cerebrospinal fluid leak. This, in addition to preservation of the facial nerve, middle and inner ear functions, constituted the main advantages of this approach. Lower cranial nerve deficit formed the major morbidity in the present series and is still an unsolved problem in such cases.