[Trigeminal neuromas: modern diagnosis and treatment]. / Trigeminal'nye nevrinomy: sovremennaya diagnostika i lechenie.

Trigeminal neuroma (TN) is a benign neoplasm arising from trigeminal nerve sheath. The tumor can grow from any part of the nerve from the root in posterior cranial fossa to peripheral extracranial branches. Symptoms of trigeminal neuroma are variable and usually depend on location and dimensions of tumor. We present a review devoted to the problem of TN. Surgery was the only possible option in patients with TN for a long time. However, radiotherapy became one of the options and sometimes alternative to surgical treatment since the late 1980s. Besides active management of patients with TN, follow-up with regular radiographic control of small asymptomatic tumors also seems to be reasonable. When evaluating treatment outcomes, physicians consider quality of life and return to previous work and activity in addition to resection quality, neurological impairment, relapse-free period and tumor growth control. However, assessment of these indicators after certain treatment is rare. Thus, it is difficult to determine treatment strategy with maximum ratio of effectiveness and quality of life. Therefore, optimization of TN treatment is currently an urgent problem that requires further study.

[A Case of Trochlear Nerve Neurinoma Presenting with Pathological Laughter].

Trochlear nerve neurinomas are rare and solitary tumors without neurofibromatosis are extremely rare. We report a case of trochlear nerve neurinoma presenting with pathological laughter and diplopia. A 40-year-old male patient presented with diplopia and pathological laughter 2 months before admission. MRI showed a multicystic enhanced mass in the left tentorial incisura compressing the midbrain and the upper pons. The tumor was excised using the left trans-Sylvian approach with partial uncal resection. After excision of the tumor, the left trochlear nerve was identified on the surface of the lateral midbrain. The nerve was connected to the tumor. Pathological laughter completely resolved after the operation. This is the second reported case of trochlear nerve neurinoma presenting with pathological laughter. The lesion responsible for pathological laughter could be the midbrain, upper pons, diencephalon, or all of these.

The influence of prophylactic vasoactive treatment on cochlear and facial nerve functions after vestibular schwannoma surgery: a prospective and open-label randomized pilot study.

OBJECTIVE: Facial nerve paresis and hearing loss are common complications after vestibular schwannoma surgery. Experiments with facial nerves of the rat and retrospectively analyzed clinical studies showed a beneficial effect of vasoactive treatment on the preservation of facial and cochlear nerve functions. This prospective and open-label randomized pilot study is the first study of a prophylactic vasoactive treatment in vestibular schwannoma surgery. METHODS: Thirty patients were randomized before surgery. One group (n = 14) received a vasoactive prophylaxis consisting of nimodipine and hydroxyethylstarch which was started the day before surgery and was continued until the seventh postoperative day. The other group (n = 16) did not receive preoperative medication. Intraoperative monitoring, including acoustic evoked potentials and continuous facial electromyelograms, was applied to all patients. However, when electrophysiological signs of a deterioration of facial or cochlear nerve function were detected in the group of patients without medication, vasoactive treatment was started immediately. Cochlear and facial nerve function were documented preoperatively, during the first 7 days postoperatively, and again after long-term observation. RESULTS: Despite the limited number of patients, our results were significant using the Fisher's exact test (small no. of patients) for a better outcome after vestibular schwannoma surgery for both hearing (P = 0.041) and facial nerve (P = 0.045) preservation in the group of patients who received a prophylactic vasoactive treatment. CONCLUSION: Prophylactic vasoactive treatment consisting of nimodipine and hydroxyethylstarch shows significantly better results concerning preservation of the facial and cochlear nerve function in vestibular schwannoma surgery. The prophylactic use is also superior to intraoperative vasoactive treatment.

Pathological laughter in trigeminal schwannoma: case report and review of the literature.

Pathological laughter is an uncommon manifestation of neurosurgical diseases. Very few cases of trigeminal schwannoma have been reported in the literature presenting with pathological laughter as a predominant symptom. We are reporting on a case of multi-compartmental trigeminal schwannoma presenting as pathological laughter and discuss a review of the literature. A 23-year-old lady presented with pathological laughter, along with symptoms pertaining to other cranial nerves and cerebellar dysfunction. Magnetic resonance imaging (MRI) of the brain was suggestive of a dumbbell-shaped mass in the middle and posterior cranial fossa on the left side, causing significant compression of the pons. She was investigated and operated for multi-compartmental trigeminal schwannoma. Following surgery, abnormal laughter disappeared immediately and no recurrence of symptoms was -present for a follow-up of 16 months. This case supports the role of the brainstem, especially the pons, in the control of laughter and, perhaps, of the medial temporal lobe too.

[Paraganglioma of the head and neck--tumor control, functional results and quality of life]. / Paragangliome des Kopf-Hals-Bereiches--Tumorkontrolle, funktionelle Ergebnisse und Lebensqualität nach Operation.

BACKGROUND: Surgical therapy for paragangliomas (PG) of the head and neck is, due to the alternatives of radiation therapy and wait-and-scan strategy and because of postoperative morbidity, under ongoing discussion. MATERIAL AND METHODS: Between 1981 and 2004, 79 patients with 94 PG of the head and neck were treated at our department. These patients had follow-up examination within a clinical trial considering tumor control, functional results and for the first time neuropsychologically evaluated postoperative quality of life. Mean follow-up time was 65 months (1 to 228 months). RESULTS: Among the 94 PG there were 19 carotid body (GCP), 12 vagal nerve (GVP) and 63 jugular-tympanal paragangliomas (JTP). Of these, 87 tumors underwent surgery. In 68 patients (78.1 %), the tumor could be removed completely. In particular, complete resection of GCP was achieved in 100 %, of GVP in 90.9 %, of JTP type A in 100 %, of JTP type B in 83.3 %, of JTP type C in 66.6 % and of JTP type D in 61.5 %. During the follow-up period, residual or recurrent tumors were diagnosed in 17 patients (19.5 %). Six of the seven residual PG were observed by magnetic resonance tomography and did not show growth. One residual PG and 6 recurrencies were resected completely. One recurrent tumor was radiated and 3 others are under observation without showing growth tendencies. Two patients died postoperatively due to borderline operations of extended tumors. The quality of life after PG surgery showed a SIP of 4.8, which is comparably much better than after acoustic neuroma surgery (SIP 10.3). CONCLUSION: Whereas complete tumor resection of GCP and JTP types A and B is almost ever possible without cranial nerve palsies, surgery of GVP and advanced JTP causes often severe functional deficits. However, postoperative quality of life is mostly good. Nevertheless, advanced PG require an individualized therapeutic regime also including radiation and observation of tumor growth.

Localized transcranial electrical motor evoked potentials for monitoring cranial nerves in cranial base surgery.

OBJECTIVE: To describe a novel monitoring technique that allows "functional" assessment of cranial nerve continuity during cranial base surgery. METHODS: Facial motor evoked potentials (MEP) in 71 consecutive patients were obtained by localized transcranial electrical stimulation in all patients requiring facial nerve monitoring during the period from November 2002 to August 2004. With transcranial electrical stimulation localized to the contralateral cortex, facial nerve MEPs are obtained through stimulation of more proximal intracranial structures. RESULTS: Logistic regression revealed that the final-to-baseline facial MEP ratio predicted satisfactory (House-Brackmann Grade 1 and 2 function) immediate postoperative facial function (0.005 > P > 0.0005). Contingency table analysis showed high correlation (chi2, P < or = 2 x 10(8)) and acceptable test characteristics using a 50% final-to-baseline MEP ratio. CONCLUSION: Facial nerve MEPs recorded intraoperatively during cranial base surgery using the proposed technique predicts immediate postoperative facial nerve outcome. This technique can also be used to monitor other motor cranial nerves in cranial base surgery.

Pathological laughter in a patient with trigeminal neurinoma.

We present a 47-year-old woman with a long history of anxiety and a more recent history of shock-like facial pain and episodes of laughter without any motivation. She could not explain the laughing bursts and did not have a sense of mirth preceding it. On neurological examination she presented a VI nerve palsy and trigeminal hypoesthesia (V2 and V3) on the right side. Magnetic resonance imaging exhibited a large cystic lesion on the right middle fossa causing significant compression on the brain stem. A frontoorbitozygomatic and pretemporal combined approach was performed. During intra and extradural exploration a large tumor was found on the trigeminal nerve. The whole lesion was resected, revealing to be a neurinoma on pathological exhamination. She maintained a VI nerve palsy but had complete remission of the unmotivated laughing episodes during the one year follow up.

Pathological laughter as a presenting symptom of massive trigeminal neuromas: report of four cases.

OBJECTIVE AND IMPORTANCE: This is a report of four cases of huge trigeminal neuromas that presented with the principle symptom of pathological laughter (PL). CLINICAL PRESENTATION: All four patients were male and were in either the third or fourth decade of life. In addition to PL, there were neurological deficits related to trigeminal nerve, brainstem, and cerebellar dysfunctions. INTERVENTION: All tumors were radically excised via a lateral basal temporal approach. The PL was cured immediately after surgery. CONCLUSION: PL sometimes precedes other neurological manifestations and may be a useful localizing sign. The clinical and radiological features in our cases suggest that PL is a result of extra-axial compression of the pons and adjoining neural structures.

A comparison of inter-aural attenuation with the Etymotic ER-3A insert earphone and the Telephonics TDH-39 supra-aural earphone.

One of the many reported advantages of the insert earphone over the supra-aural earphone is increased inter-aural attenuation (IA). Minimum values of IA determine the need for masking of the non-test ear in air-conduction audiometry. The aim of the present study was to measure inter-aural attenuation for the Etymotic Research ER-3A insert earphone (with deep and shallow insertion of the ear plug within the ear canal) and compare this with the supra-aural Telephonics TDH-39/MX41-AR earphone/cushion combination. Subjects were 18 adults ranging in age from 38 to 68 years (mean 50 years). Each subject had no hearing in one ear following translabyrinthine surgery for removal of an acoustic neuroma. The opposite ear had hearing thresholds better than 40 dB HL and an air-bone gap of less than 10 dB at any audiometric frequency. Pure tone air-conduction thresholds were obtained in the range 0.25-8 kHz. Deep insertion of the insert earphone was deemed to occur when the outside edge of the ear plug was flush with the entrance of the ear canal. Shallow insertion was deemed to occur when half of the ear plug (6 mm) was inside the entrance of the ear canal. IA was defined operationally as the difference between the good-ear and poor-ear not-masked air conduction threshold for a given audiometric frequency and earphone. The results show that the TDH-39/MX41-AR combination provides a median IA of approximately 60 dB with a lower limit of approximately 45 dB. Greater IA was obtained with the ER-3A insert earphone but this depended on the depth of insertion. With a deep insertion, the 1A values were some 15-20 dB greater than with the supra-aural earphone. Although frequency-specific IA values are provided, a simple rule of thumb is to apply masking to the non-test ear when the pure tone airconduction signal from the ER-3A insert earphone exceeds the bone conduction threshold of the non-test ear by 55 dB HL or more. If it is not possible to obtain a deep insertion depth this value should be reduced by 5 dB.

Trochlear nerve neurinoma presenting as pathological laughter.

A case of trochlear nerve neurinoma in a 48-year-old women is reported. She presented with pathological laughter as her principal symptom which was cured by tumour resection. A brief review of the available literature on the subject is reported.

Pathological laughter as a presenting symptom of trigeminal neurinoma--case report.

A 26-year-old male presented with a trigeminal neurinoma manifesting as pathological laughter. After resection of the large tumor, the symptom disappeared completely. Pathological laughter sometimes precedes other manifestations of tumors around the brainstem and may be a useful localizing sign.

Direct cochlear nerve action potentials as an aid to hearing preservation in middle fossa acoustic neuroma resection.

A new application of auditory evoked potentials using direct cochlear nerve action potentials (CNAPs) for monitoring middle fossa acoustic neuroma resection with attempted hearing preservation is described. Twenty patients have been studied to date. With this technique, a monitoring electrode is secured between the floor of the internal auditory canal and the dura adjacent to the cochlear nerve in an extradural location. Standard auditory evoked potential techniques with click stimuli and microelectrical recording allow observation of nearfield waveforms in seconds versus several minutes required for farfield potentials recorded from the scalp. Advantages of this technique over auditory brainstem response monitoring may include nearly real time measurement of potentials, improved surgeon learning curve and possibly higher rates of hearing preservation, and applicability to all patients undergoing hearing-preservation surgery independent of presence or absence of ABR tracing. Immediate changes in amplitude and latency of waveforms appear to compare with reversible and irreversible intraoperative auditory system damage, thereby guiding surgical maneuvers.

Ukrain therapy of a recurrent astrocytoma of the optic nerve (case report).

An eight year old girl was twice operated (1989 and 1991) for a Grade I astrocytoma of the chiasma. Because of early recurrence and the fact that the tumour could only be extirpated subtotally Ukrain monotherapy was initiated.

Determinants and impact of headache after acoustic neuroma surgery.

Headache after acoustic neuroma surgery is known to occur clinically, but has not been studied systematically until recently. In the present study, 155 patients were surveyed regarding their experience of headache and associated symptoms following resection of an acoustic neuroma: 73 percent (n = 98) of patients undergoing suboccipital resection of an acoustic neuroma and 53 percent (n = 8) of patients undergoing translabyrinthine resection of acoustic neuroma complained of headache following surgery. The average pain intensity was greater for the suboccipital approach. Only 9 percent (n = 14) reported troublesome or frequent headaches preoperatively. Headache was described most often as tension type, with episodic acute exacerbations mimicking migraine. Clinical observations suggest that most patients are treated successfully with various combinations of reassurance, tricyclic antidepressants, nonsteroidal anti-inflammatory medications, trigger-point injections, adjunctive stress management techniques (relaxation), and physical therapy. The impact of recurrent headache on work and recreational function is notable. Several possible pathophysiological and biopsychosocial models are proposed to account for the prevalent headache problem. Although spontaneous resolution usually occurs over time, additional study is needed to determine the natural history of postoperative headache once it occurs.

Surgery of giant gliomas of chiasma and IIIrd ventricle.

During a period of 17 years (from 1976 till now) 45 patients with giant gliomas of the chiasma and the IIIrd ventricle out of a total amount of 120 patients with hypothalamic gliomas were operated. The following classification of tumours was used: I) tumours with predominant anterior growth; II) tumours which infiltrate chiasma and penetrate into the IIIrd ventricle; III) gliomas of the floor of the IIIrd ventricle and the chiasma, growing into the ventricle cavity; IV) tumours of the chiasma, optic tract and thalamus. The authors come to the conclusion, that surgical removal of giant tumours of the chiasma and the IIIrd ventricle, though risk, may result in an improvement or stabilisation of visual functions (77%) and a long period free from recurrencies (9.5%). The postoperative period is relatively favourable and the mortality is low (6%). The main contraindication in our opinion is a wide infiltration of adjacent brain structures by the tumour and spreading along both optical tracts. We consider the giant size of a tumour in itself a sufficient indication for surgery.

Thyroplasty in the functional rehabilitation of neurotologic skull base surgery patients.

Definitive management of lesions of the lateral cranial base is surgical. Functional outcome is dependent on cranial nerve preservation. In 1988 an effort was made to decrease the incidence of tracheotomy, the duration of hospital stay, and the period prior to unassisted oral intake, by establishing more immediate acquisition of glottic competence through laryngeal rehabilitation. The experience of one author (JLN) in over 40 phonosurgical procedures under local anesthesia is presented. Although tracheotomy provides excellent airway protection, it is accompanied by substantial morbidity. The technique of phonosurgery has dramatically improved recovery and functional outcomes of neurotologic skull base surgery patients, enabling them to realize "cure" rather than "control" of their disease.

Tympanic and transtympanic electrocochleography in acoustic neuroma and vestibular nerve section surgery.

Eighth nerve action potential (AP) amplitudes and latencies and cochlear microphonic (CM) amplitudes were compared using tympanic and transtympanic electrocochleography (ECOG) in two patient groups. Tympanic ECOG was performed with a wick electrode placed on the tympanic membrane (TM). Transtympanic ECOG was performed with a needle electrode placed on the promontory of the anesthetized patient. Eighteen subjects were tested by tympanic ECOG as part of a preoperative assessment for either acoustic neuroma removal or transection of the vestibular portion of the eighth cranial nerve. Surgery occurred within 1 week of the preoperative evaluation. Intraoperative auditory monitoring was performed using transtympanic ECOG. Baseline recordings were compared to the preoperative tympanic ECOG data. Stimuli were condensation and rarefaction clicks and tone bursts, presented by an insert earphone. As expected, the two methods resulted in essentially identical response latencies and large amplitude differences, although the response amplitudes were extremely variable. The AP amplitude and the CM amplitude did not increase by the same factor with the transtympanic (TT) electrode compared to the tympanic electrode. On comparison of preoperative and intraoperative response amplitudes with regard to stimulus polarity, tympanic electrocochleography appears to be a useful method of gathering preliminary information on the status of the patient's auditory system. In this study, tympanic ECOG was found to have some predictive value when trying to ascertain the best intraoperative monitoring situation.

[The results of direct electrostimulation of the involved optic nerves in neurosurgical patients]. / Rezul'taty priamoi élektrostimuliatsii porazhennykh zritel'nykh nervov u neuirokhirurgicheskikh bol'nykh.

The article generalizes experience in the restoration of vision by direct stimulation of damaged optic nerves after operations for pathological conditions of the chiasmal-sellar region (tumors of the chiasmal-sellar region, optochiasmic arachnoiditis, damage of the optic nerve in the bone canal) in 111 patients. The therapeutic effect was favourable in two thirds of the patients. Indications are determined for the use of the method in various types, duration, and severity of the disease. The use of the method with due regard for the determined indications increases the reliability, degree, and rate of restoration of vision in patients who underwent operation.

Electrical stimulation of cochlear nucleus in man.

Auditory percepts can be produced by electrical stimulation of the cochlear nucleus in man. The ability to locate accurately and stimulate selectively the cochlear nucleus after removal of an acoustic schwannoma was confirmed in this patient. The surgical approach, electrode design, and a discussion of the results and concerns of electrical stimulation are reviewed.

Gliomas of visual pathways and hypothalamus in children--a preliminary report.

26 children with gliomas of the visual pathway and hypothalamus were seen during 5 years. 4 of them had intraorbital tumors, in 22 children tumors were localized in the chiasmal/hypothalamic regions. In 25 patients the tumors were surgically explored. All 4 intraorbital gliomas were radically removed using a transcranial approach. Exploration without biopsy was performed 7 times, exploration plus limited biopsy in 3 cases. In the remaining 11 operated children partial or subtotal removal of the tumor was possible. One of the 18 histologically verified tumors was an anaplastic glioma, the others were typical pilocytic astrocytomas. 12 children had hydrocephalus. 7 patients died, 19 are still alive. The operative mortality was 4 out of our 25 operated cases (16%). All of these patients had large tumors with posterior spread into the hypothalamus. In future, surgery in these children should be confined to exploration and limited biopsy followed by radiotherapy. We advocate exploration and biopsy in all chiasma/hypothalamic tumors. The growth potential of these tumors is individually variable. We recommend to follow-up all patients at 3 months' intervals by means of visual evoked potentials, visual acuity, fundoscopy and visual field testing. CT scans and X-rays of the optic canals should be performed once a year. Surgery should only be considered if clinical and/or neuroradiological progression has been documented.