Contralateral blink reflex abnormality in right trigeminal neuralgia: A case report

@#Trigeminal neuralgia can be a manifestation of contralateral cerebellopontine angle tumor. We report here a 34 year old female patient who presented with right sided facial pain in first and second divison of right trigeminal nerve but her blink reflex was abnormal on the left side. Her brain MRI revealed a left cerebellopontine angle tumor displacing the pons as well as the basilar artery. The distortion and displacement of brainstem and the basilar artery contribute to the genesis of the trigeminal neuralgia contralaterally

Bilaterally Abnormal Head Impulse Tests Indicate a Large Cerebellopontine Angle Tumor

BACKGROUND AND PURPOSE: Tumors involving the cerebellopontine angle (CPA) pose a diagnostic challenge due to their diverse manifestations. Head impulse tests (HITs) have been used to evaluate vestibular function, but few studies have explored the head impulse gain of the vestibulo-ocular reflex (VOR) in patients with a vestibular schwannoma. This study tested whether the head impulse gain of the VOR is an indicator of the size of a unilateral CPA tumor. METHODS: Twenty-eight patients (21 women; age=64+/-12 years, mean+/-SD) with a unilateral CPA tumor underwent a recording of the HITs using a magnetic search coil technique. Patients were classified into non-compressing (T1-T3) and compressing (T4) groups according to the Hannover classification. RESULTS: Most (23/28, 82%) of the patients showed abnormal HITs for the semicircular canals on the lesion side. The bilateral abnormality in HITs was more common in the compressing group than the non-compressing group (80% vs. 8%, Pearson's chi-square test: p<0.001). The tumor size was inversely correlated with the head impulse gain of the VOR in either direction. CONCLUSIONS: Bilaterally abnormal HITs indicate that a patient has a large unilateral CPA tumor. The abnormal HITs in the contralesional direction may be explained either by adaptation or by compression and resultant dysfunction of the cerebellar and brainstem structures. The serial evaluation of HITs may provide information on tumor growth, and thereby reduce the number of costly brain scans required when following up patients with CPA tumors.

Meningioma related trigeminal neuralgia presenting as odontalgia: A case report

Classical trigeminal neuralgia is characterized by recurrent attacks of lancinating pain in the trigeminal nerve distribution, and no cause of the symptoms can be identified, other than vascular compression. This type of injury may rarely be caused by identifiable conditions, including tumor in the cerebellopontine angle. If the patient is suspected for secondary trigeminal neuralgia, further evaluation is required to diagnose and treat correctly. We report a case of a 49-year-old woman with a 1-month history of facial pain, who was initially misdiagnosed as odontalgia, and even treated with the extraction of her molar teeth. This case with the review of secondary trigeminal neuralgia may highlight the difficulties of diagnosis, and the importance of early diagnostic imaging, when trigeminal neuralgia occurs with a brain tumor.

Bilateral Vestibulopathy due to Bilateral Cerebellopontine Angle Tumors in Neurofibromatosis Type 2

Bilateral vestibulopathy (BV) is characterized by oscillopsia and imbalance during locomotion. Half of the cases of BV are idiopathic, and BV due to brain tumor has been reported only rarely. We report a case of BV due to bilateral cerebellopontine-angle tumors in a patient with neurofibromatosis type 2. Careful history on oscillopsia and imbalance during locomotion, and regular follow-ups using the head-impulse test and dynamic visual acuity are warranted in patients with neurofibromatosis type 2.

Collet-Sicard Syndrome with Dysphagia due to Cerebellopontine Angle Meningioma : A case report

Collet-Sicard syndrome is one of the syndromes of the multiple lower cranial nerve palsies, characterized by unilateral paralysis of 9th through 12th cranial nerves. Meningioma has rarely been reported as a cause of Collet-Sicard syndrome. This case was a 34-year-old man who had dysphagia, loss of taste, and dysarthria. Brain MRI showed a mass in the left cerebellopontine angle. Videofluoroscopic swallowing study revealed severe dysphagia during pharyngeal phase and cricopharyngeal dysfunction. Laryngoscopy revealed left vocal cord palsy, and eletrodiagnostic study showed paralysis of the left IX, X, XI and XII cranial nerves.

Microsurgery for secondary trigeminal neuralgia: Clinical analysis of 37 cases / 中国微创外科杂志

Objective To explore the curative effect of microsurgery via posterior approach through the sigmoid sinus in the treatment of secondary trigeminal neuralgia. Methods Clinical data of 37 cases of trigeminal neuralgia secondary to cerebellopontine angle (CPA) tumor from October 2000 to July 2006 were studied, including 18 cases of cholesteatoma, 8 cases of meningoma, 6 cases of acoustic neuroma, and 5 cases of trigeminal schwannoma. All tumors were removed with microsurgery through a posterior approach by way of the sigmoid sinus. Results A total resection was achieved in 23 cases, a subtotal resection in 10 cases, and a partial resection in 4 cases. Symptoms of neuralgia disappeared in 35 cases (including 32 cases of immediate relief and 3 cases of relief 2 months after operation). There was no improvement in 2 cases. Conclusions Microsurgery via posterior approach through the sigmoid sinus in the treatment of secondary trigeminal neuralgia is safe and effective.

Four Cases of Large Cerebellopontine Angle Tumors Removed by Translabyrinthine Approach / 대한이비인후과학회지

Several approaches to the cerebellopontine angle and internal auditory canal have been described for the removal of large acoustic tumors. Of these, the translabyrinthine removal of the large cerebellopontine angle tumors requires extensive removal of bones in order to manage the low-lying tegmen, the anterior sigmoid sinus, and the high jugular bulb. We removed 4 large cerebellopontine angle tumors by the translabyrinthine approach alone. All tumors were totally removed with acceptable facial nerve function. There was a case of CSF leak which was repaired at the revision surgery.

Electrophysiologic Neuromonitoring Changes during Tumor Surgery in Cerebellopontine Angle

BACKGROUND: Intraoperative neurophysiologic monitoring(INM) is well known to be useful method to reduce intraoperative complications during tumor surgery in cerebellopontine angle(CPA). We investigated the changes of INM during the surgery. It might be helpful to keep one's eyes on which monitoring modalities are reluctant to change during the operation. METHODS: We included 49 subjects who had undergone CPA tumor surgery under INM. Their pathology was as follows; vestibular schwannoma in 37, other cranial nerve schwannoma in 3, meningioma in 5 , cyst in 2. The modalities of monitoring were short latency auditory evoked potentials(AEP), somatosensory evoked potentials(SEP) , facial and trigeminal nerve EMG(EMG). Stimulation of SEP was on left or right median, posterior tibial nerves. We studied the frequency of abnormal INM changes and the factors affecting it. RESULTS: The subjects who had abnormal changes in at least one monitoring modality were 19(38.8.%). AEP changes were in 6.1%, SEP in 12.2% and EMG in 24.5%. The AEP monitoring had no potentials from II through V wave in 28 subjects(57.1%). SEP monitoring had improvement in 2 subjects and aggravation in 6, especially involved in median nerve SEP. Tonic EMG activities were observed in 3 facial muscles of 3 subjects, 2 of 4, 1 of 5. Regarding the pathology of tumor, meningioma had much more changed INM than vestibular schwannoma. The volume of tumor was bigger in abnormal INM group than normal group although it is not statistically significant. Also abnormal SEP and EMG group had bigger mass than normal group. CONCLUSIONS: INM has frequent electrophysiologic changes during tumor surgery in CPA. Especially EMG can be changed the most frequently. The larger tumor are, the more frequently abnormal changes in INM of CPA tumor surgery are.

Neurotologic Analysis of Cerebellopontine Angle Tumor / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The authors performed seven removal operations cerebellopontine angle tumor, six of which were acoustic neuroma. The purpose of this research is to analyze different cases of cerebellopontine angle tumor, determine their clinical characteristics, and evaluate the efficacy of various surgical approaches. MATERIALS AND METHODS: We performed neurotological analysis of both clinical characteristics and the results of each surgical approach for seven patients who have been treated for cerebellopontine angle tumor. RESULTS: The most frequent symptom was the complaint of hearing disturbance, where the mean PTAs measured were 66 dB, and the mean speech discrimination score was 35%. The average size of tumors measured by MRI was 3.9 cm. The following surgical approaches were used: translabyrinthine in 4 cases, modified translabyrinthine in 2 cases, transcochlear in one case. Complete removal of the tumor was possible in six patients. Facial nerve was preserved anatomically in six patients, and hearing preservation was possible in one patient for whom we performed the modified translabyrinthine approach. CONCLUSION: Early diagnosis and treatment is important in order to improve the facial nerve function after the operation. The modified translabyrinthine approach is worth performing for hearing preservation.

Cerebellopontine Angle Lipoma Representing Trigeminal Neuralgia: Case Report

A case of rare symptomatic cerebellopontine angle lipoma treated by surgical decompression is described. In this 28-year-old male with intermittent facial pain 17 years, a mass was noted in the right cerebellopontine angle on C-T and MRI. Partial removal of the mass was made for decompression of the lesion from the trigeminal nerve root entry zone. The surgical biopsy results was lipoma. This represents, to our knowledge, the first lipoma in the cerebellopontine angle reportes in the Korean literature.

Clinical Analysis of Cerebellopontine Angle Tumors

Although the cerbellopontine area is a relatively small portion in the intracranial cavity, various kinds of tumors could be found in this area due to it's anatomical characteristics. There are several cranial nerves, brain stem, aquaduct of Sylvius, cerebellum and important vascultures in this area, so various neurological symptoms and signs could be occurred when the tumor developed in this region. A clinical analysis of 49 patients with cerebellopontine angle tumors during the last 5 years at the department of neurosurgery of C.U.M.C was done retrospectively. There were 19 men and 30 women with mean age of 43.8 years. The most frequent tumor was acoustic neuroma-37 of these patients(75.8%) and followed by meniningioma and ependymoma in frequency. The most frequent clinical symptom were headache and hearing disturbance. On the radiological evaluation, simple plain X-ray film showed normal in 43.3% and CT scan of the brain showed hydrocephalus and asymmetric cistern in 28 % and in 25% of patients respectively. Surgery was done by total extirpation in 19 cases and partial removal in 23 cases and the result were excellent or good in 29 cases.

Retroamstoid Suboccipital Approch to Cerebellopontine Angle Tumors

Eight patients with cerebellopontine angle tumors larger than 3cm in diameter were operated on through retromastoid suboccipital approach with microsurgical technique. Patients were placed in lateral decubitus position with the head fixed by a three point Mayfield head-pin and the face was turned about fourty degree down as the imaginary petrous ridge directed to the floor, vertically. There are six acoustic neuromas, one meningioma and one hemangioblastoma presented in this report. The total tumor removal was done in all cases but one and the facial nerve was preserved anatomically in six of eight patients and in one of the other two the nerve was anastomosed in the same operative field following tumor excision. Functionally, two cases of facial paresis and one facial paralysis were resulted. Above results show that this approach is just suitable for total removal of the large cerebellopontine angle tumors with preservation of the facial nerve by neurosurgeon under best obtained neuroanatomical knowledge.