1/53. Schwannoma in patients with isolated unilateral trochlear nerve palsy.PURPOSE: To describe the clinical features of patients with isolated unilateral trochlear nerve palsy secondary to imaging-defined schwannoma of the trochlear nerve. methods: A chart review of all patients seen at the Neuro-ophthalmology Unit at Emory University since 1989. Of 221 patients with trochlear nerve palsy, six had a lesion consistent with a trochlear nerve schwannoma. RESULTS: The six patients had isolated unilateral trochlear nerve palsy. Duration of diplopia before diagnosis averaged 6 months. magnetic resonance imaging demonstrated circumscribed, enhancing lesions along the cisternal course of the trochlear nerve, all measuring less than 5 mm in greatest dimension. Five of the patients were seen in follow-up, over periods ranging from 11 to 26 months from initial presentation (mean, 15.6 months; standard deviation, 6.0 months). All of these patients remained stable except one, who was slightly worse at 15 months by clinical measurements and magnetic resonance imaging. None of these patients have developed additional symptoms or signs of cranial nerve or central nervous system involvement. CONCLUSIONS: The differential diagnosis of an isolated unilateral fourth cranial nerve palsy should include an intrinsic neoplasm of the trochlear nerve. magnetic resonance imaging is useful, both for diagnosis and follow-up. These patients can remain stable and may not require neurosurgical intervention.- - - - - - - - - - ranking = 1keywords = central nervous system, nervous system (Clic here for more details about this article) |
2/53. Cutaneous-evoked tinnitus. I. Phenomenology, psychophysics and functional imaging.DC00166e and acute unilateral deafferentation of the auditory periphery (auditory and vestibular afferents) can induce changes in the central nervous system that may result in unique forms of tinnitus. These tinnitus perceptions can be controlled (turned on and off) or modulated (changed in pitch or loudness) by performing certain overt behaviors in other sensory/motor systems. Clinical reports from our laboratory and several other independent sources indicate that static change in eye gaze, from a neutral head-referenced position, is one such behavior that can evoke, modulate and/or suppress these phantom auditory events. This report deals with a new clinical entity and a form of tinnitus that can be evoked directly by cutaneous stimulation of the upper hand and fingertip regions. In 2 adults, cutaneous-evoked tinnitus was reported following neurosurgery for space-occupying lesions at the base of the skull and posterior craniofossa, where hearing and vestibular functions were lost completely and acutely in one ear (unilateral deafferentation) and facial nerve paralysis (unilateral deefferentation) was present either immediately following neurosurgery or had occurred as a delayed-onset event. Herein, we focus on the phenomenology of this discovery, provide perceptual correlates using contemporary psychophysical methods and document in one individual cutaneous-evoked tinnitus-related neural activity using functional magnetic resonance imaging. In a companion paper, neuroanatomical and physiological interactions between auditory and somatosensory systems, possible mechanistic accounts and relevant functional neuroimaging studies are reviewed.- - - - - - - - - - ranking = 1keywords = central nervous system, nervous system (Clic here for more details about this article) |
3/53. Sympathetic schwannoma: a case report.Schwannomas (also known as Neurilemomas or Neurinomas) are benign tumors of the nervous system that originate in the neural sheath and most commonly occur as solitary encapsulated subcutaneous tumors in otherwise healthy individuals. When they present as multiple tumors, they are histologically indistinguishable from the solitary tumors and, in such a case, they may be associated with neurofibromatosis 2 (NF2) in which the sensory roots of the cranial and spinal nerves are affected more often than the motor roots and the hallmark tumor of which is a vestibular schwannoma (also known as acoustic neuroma). They also may exist as a distinct clinical entity without any stigmata of neurofibromatosis known as schwannomatosis. Generally, schwannomas are less than 5 cm in diameter but sizes greater than 14 cm have been reported. They present as slow growing masses and may present with pain or neurological symptoms. Here we report a patient with sympathetic schwannoma who presented with right flank pain.- - - - - - - - - - ranking = 0.43629503222415keywords = nervous system (Clic here for more details about this article) |
4/53. The clinical spectrum of schwannomas presenting with visual dysfunction: a clinicopathologic study of three cases.Schwannomas (neurilemomas) are benign tumors that arise from schwann cells in the peripheral nervous system. The most commonly involved nerves that cause neuro-ophthalmic manifestations are cranial nerves V and VIII. In this series of three women, schwannomas presented as intraconal masses that mimicked a cavernous hemangioma, a superior orbital mass transgressing the superior orbital fissure, and an expansive frontal lobe mass with clinical symptoms and signs of increased intracranial pressure. Although all three complained of visual blurring, none of our patients presented with Vth or VIIIth cranial nerve dysfunction. Histopathologic studies demonstrated well-circumscribed, encapsulated spindle-cell lesions with classic Antoni A and B patterns. Histopathologic examination is essential to confirm the diagnosis of a schwannoma that may be otherwise clinically confusing. Direct optic nerve compression, globe indentation with induced hyperopia, or increased intracranial pressure with optic nerve compromise may be responsible for visual symptoms. A multidisciplinary approach is often required because of the size and location of schwannomas.- - - - - - - - - - ranking = 0.43629503222415keywords = nervous system (Clic here for more details about this article) |
5/53. Primary melanocytic schwannoma of cervical sympathetic chain.BACKGROUND: Primary melanocytic schwannoma arising from the cervical sympathetic chain is a rare pigmented nerve sheath tumor. Two cases are presented from an academic medical center. patients and methods patients were initially seen with an enlarging neck mass associated with sympathetic nervous system dysfunction. radiography demonstrated a mass located posterior to the carotid sheath. Primary therapy consisted of surgical excision and postoperative radiation therapy. RESULTS: The tumors were found to be melanocytic schwannomas arising from the cervical sympathetic chain. The pathologic characteristics of this neoplasm are reviewed. One patient remained disease free for 12 years after treatment, whereas 1 patient died as a result of local recurrence and distant metastases. CONCLUSIONS: Melanocytic schwannoma of the cervical sympathetic chain is a rare nerve sheath tumor of the head and neck that may be misdiagnosed as malignant melanoma. The clinical behavior of this neoplasm is variable. Preoperative neurologic findings, anatomic location, electron microscopy, and immunohistochemistry findings help to establish the diagnosis, and electron microscopy may have a role in distinguishing between benign and malignant lesions. Complete surgical excision is the treatment of choice.- - - - - - - - - - ranking = 0.43629503222415keywords = nervous system (Clic here for more details about this article) |
6/53. Intracanalicular schwannoma of the facial nerve: a manifestation of neurofibromatosis type 2.Primary facial nerve tumors, which are relatively uncommon, can present a diagnostic dilemma based on their location and variable pattern of symptoms. Of primary cranial nerve tumors, schwannomas of the facial nerve rank third in frequency after those of the eighth and fifth cranial nerves. We report an illustrative case of an intracanalicular schwannoma associated with several central nervous system tumors, consistent with neurofibromatosis type 2. Initially assumed to be an eighth cranial nerve tumor, the schwannoma was found intraoperatively to arise from the facial nerve. early diagnosis and treatment enabled excision of the tumor without sacrifice of the facial nerve. facial nerve schwannomas can resemble acoustic schwannomas in their clinical presentation. Only a heightened level of clinical vigilance will point to the correct diagnosis and result in an optimal therapeutic outcome for patients with these rare tumors.- - - - - - - - - - ranking = 1keywords = central nervous system, nervous system (Clic here for more details about this article) |
7/53. Intraventricular malignant triton tumour.The authors present the clinical and pathological features of a malignant triton tumour (MTT) in the lateral ventricle with neurofibromatosis type 1. A 57 year-old man presented with disorientation and memory disturbance. A Computed tomographic scan and magnetic resonance imaging studies revealed an enhancing lesion in the left lateral ventricle. A parieto-occipital transcallosal approach was taken and resection of the lesion was performed. The operative findings suggested that the tumour arose from the perivascular nerves. The final pathological diagnosis was a MTT. This is the first case of an intraventricular MTT. Aggressive treatment including radical surgery combined with radiochemotherapy is recommended for a MTT of the central nervous system.- - - - - - - - - - ranking = 1keywords = central nervous system, nervous system (Clic here for more details about this article) |
8/53. Type II neurofibromatosis presenting as quadriceps atrophy.A young woman aged 26 years presented with atrophy of the left quadriceps progressing over one year. magnetic resonance imaging (MRI) showed a large lesion of the lumbar plexus compatible with neurinoma. Cerebral MRI revealed a lesion in the right eighth cranial nerve also compatible with neurinoma. On further questioning of the patient, it was learned that her mother had undergone surgery twice for acoustic neurinoma. Type II neurofibromatosis was diagnosed from the basis of clinical picture, neuroimaging findings and family history. This case is unusual for the lack of central nervous system (CNS) symptoms. Expansive radicular lesions compatible with neurinoma should prompt cerebral MRI. Regular examination of family members at risk and early diagnosis can decrease the high mortality associated with this condition.- - - - - - - - - - ranking = 1keywords = central nervous system, nervous system (Clic here for more details about this article) |
9/53. Intraoperative diagnosis of tanycytic ependymoma: pitfalls and differential diagnosis.Smear preparations have become increasingly popular in the intraoperative assessment of central nervous system pathology. The cytological features of a histologically proven tanycytic ependymoma are presented with the pitfalls and differential diagnosis. The smear preparation showed a glial neoplasm composed of cells with long, bipolar glial processes and oval to spindle-shaped nuclei resembling those seen in pilocytic astrocytoma smears. The smear characteristics of an ependymoma usually show remarkably uniform round-to-oval nuclei, fluffy glial processes, and a perivascular nuclear-free zone (pseudorosetting). None of these features were present in our case. The accompanying frozen section showed a fascicular spindle-cell tumor that resembled a schwanomma, a commonly reported misinterpretation of the histology of tanycytic ependymomas on frozen sections. Careful attention to the radiological findings, the surgeon's impression, and the intraoperative smear preparation details should allow one to include this uncommon entity in the differential diagnosis of spinal neoplasms.- - - - - - - - - - ranking = 1keywords = central nervous system, nervous system (Clic here for more details about this article) |
10/53. Neurofibromatosis type 2 diagnosed in the absence of vestibular schwannomas. A case report and guidelines for a screening protocol for children at risk.A 5-year-old girl presented with multiple tumours of the central nervous system. As on the first MRI scan bilateral vestibular schwannomas were not detected due to their small size, she initially did not meet the criteria for neurofibromatosis type 2 (NF2), although her clinical symptoms were highly suggestive for the diagnosis. Using molecular studies, a mutation in the NF2 gene was found confirming the clinical suspicion at an early age and indicating the value of molecular analysis. Follow-up MRI 3 years later demonstrated bilateral vestibular schwannomas more clearly, since they had increased in size. CONCLUSION: In children, magnetic resonance imaging can be inconclusive for the diagnosis of neurofibromatosis type 2, since very small vestibular schwannomas may be missed. In these cases molecular studies may provide additional evidence for the diagnosis. We propose guidelines for a screening protocol for children at risk for having neurofibromatosis type 2.- - - - - - - - - - ranking = 1keywords = central nervous system, nervous system (Clic here for more details about this article) |
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