1/16. Post-traumatic olfactory dysfunction.OBJECTIVES: This study demonstrates histopathologic and immunocytochemical changes in the olfactory bulb of a patient with post-traumatic olfactory dysfunction. These results are analyzed in light of current understanding of the pathophysiology of anosmia and dysosmia following head trauma. Emphasis is placed on potential mechanisms of human regeneration and recovery. STUDY DESIGN: The current study documents the history of a patient with the initial complaint of complete anosmia following minor head trauma. Two months after the injury the patient developed persistent, severe dysosmia with debilitating weight loss. Neurosurgical treatment, including removal of the olfactory bulbs and tracts, resulted in permanent resolution of dysosmia. methods: Histopathologic and immunocytochemical analysis of the olfactory bulbs was undertaken and compared with age-matched control tissue. RESULTS: Pathological analysis of the olfactory bulb revealed a marked reduction in the number of nerve processes with few intact olfactory glomeruli compared with an age-matched control. Specific immunohistochemical staining for the olfactory neuron-specific protein OMP, however, demonstrated the presence of intact axonal projections between the olfactory mucosa and the bulb. CONCLUSIONS: These results support the hypothesis that post-traumatic anosmia involves, at least in part, damage to peripheral olfactory nerve fibers with histological changes in the olfactory bulb. Potential mechanisms for the development of post-traumatic dysosmia are also discussed.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
2/16. Neural-dural transition at the medial anterior cranial base: an anatomical and histological study with clinical applications.OBJECT: Few anatomical studies have been focused on the morphological features and microscopic anatomy of the transition from the intracranial space to the medial anterior cranial base. The authors of the current study performed histological analyses to define the structure of the transition from neural foramina to the cranial base (neural-dural transition) at the cribriform plate, particularly as related to cerebrospinal fluid (CSF) fistula formation and surgical intervention in the region. methods: The medial anterior cranial base was resected in six cadaveric specimens. Histological methods were used to study the anatomy of the region on the microscopic level. Results of these examinations revealed a multilayered neural-dural transition at the cribriform plate, which consisted of an arachnoid membrane and a potential subarachnoid space as well as dura mater, periosteum, ethmoid bone, and associated layers of submucosa and mucosa of the paranasal air spaces. A subarachnoid space was identified around the olfactory nerves as they exited the neural foramina of the cribriform plates. The dura mater eventually thinned out and became continuous with the periosteum in the ethmoid bone. The dura, arachnoid membrane, and associated potential subarachnoid space were obliterated at a place 1 to 2 mm into the olfactory foramen. The authors present a case of recurrent CSF rhinorrhea successfully treated using a technique of multilayered reconstruction with pericranium, fat, and bone. CONCLUSIONS: The findings provide an anatomical basis for CSF fistula formation in the region of the cribriform plate and help to explain the unusual presentations in patients who have CSF rhinorrhea and meningitis. These results may facilitate the treatment of CSF fistulas, repair of defects in the medial anterior cranial base, and approaches to tumors and other pathological entities in the region.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
3/16. Olfactory event-related potentials in normal subjects and patients with smell disorders.We developed a device to record olfactory event-related potentials (OERP) from the human scalp. Methyl-cyclopentenolone was used as the odorant element. A total of 50 stimuli were delivered. Each stimulus lasted 0.5 sec and was delivered once every three inspirations. Normal OERPs were obtained with this device. The positive peak latencies were approximately 350 msec (P1) and 700 msec (P2), respectively. OERPs were also recorded in 40 patients with smell disorders. A positive response at about 300-400 msec was recorded in 7 patients (all females, 15-59 years old). The other 33 patients showed no response. The high potential area of this positive peak was located in the centro-occipital region of the scalp. The latency and the high potential area of this peak were similar to P1 recorded in normal subjects. The source of this peak was considered identical to that of P1. This may be a response to the trigeminal nerve during odor administration. P2 was not recorded in the patients with smell disorders. P2 may therefore be a response to the olfactory nerve.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
4/16. Acute hyposmia in type 2 diabetes.During treatment for type 2 diabetes with a diabetic diet (without medication), a 61-year-old Japanese man suddenly developed hyposmia. The fasting plasma glucose was 208 mg/dl and haemoglobin A1c was 8.6%. On investigation, there were no indications of disease of the brain, or the nasal or paranasal sinuses. The intravenous olfaction test yielded no response, indicating suspected neural hyposmia. After 6 months, the symptoms of hyposmia improved without medication, and the intravenous olfaction test results were normal. This clinical course is very similar to that seen with diabetic neuropathy of the third and sixth cranial nerves. We speculate that hyposmia in this case may have been caused by diabetic mononeuropathy of the first cranial nerve.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
5/16. Devastating complications from alcohol cauterization of recurrent Rathke cleft cyst. Case report.Rathke cleft cysts are commonly found on autopsy but are seldom symptomatic. Conventional treatment of these lesions consists of transsphenoidal drainage with partial excision of the cyst, and recurrence is rare. Alternatively, the instillation of absolute alcohol into the cyst has been described in several reports, with no complications. The authors report on a woman with Rathke cleft cyst that recurred three times after the initial treatment; the lesion was treated with alcohol cauterization on the final recurrence with devastating complications. This 51-year-old woman presented in 1992 with headaches and visual disturbances. Admission magnetic resonance imaging revealed a sellar/suprasellar lesion that was treated with conventional surgery and was subsequently confirmed to be a Rathke cleft cyst. The patient again presented with recurrence of the cyst at 22, 26, and 31 months after the initial presentation. On the final recurrence the cyst was treated with alcohol cauterization. Postoperatively, the patient awoke blind and suffered a seizure from leakage of the alcohol. The patient remains completely blind in both eyes and is also anosmic and has left lid ptosis and exotropia, which signify damage to the first through third cranial nerves. Rathke cleft cysts have been known to recur after primary surgery; however, this is the first report of a single cyst recurring three times despite conventional surgical treatment. Additionally, this is the first report in which devastating complications from alcohol cauterization of the cyst have been described. The authors therefore advocate caution when attempting alcohol cauterization and advise that meticulous care be taken to ensure the patency of the cyst.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
6/16. Management of a sporadic malignant subfrontal peripheral nerve sheath tumor.Malignant subfrontal (olfactory) peripheral nerve sheath tumors (MPNSTs) are exceedingly rare. Although meningiomas are the most common subfrontal extra-axial lesions, it is important to recognize that MPNSTs, which are radiographically similar to meningiomas, can also be present in this location. MPNSTs require more aggressive surgical and postoperative management than meningiomas. In this paper, we describe a patient with a subfrontal MPNST with unusual histological characteristics and present a review of the literature. A 49-year-old woman presented with chronic sinusitis and progressive headaches. A neurological examination revealed left-sided anosmia. brain-imaging studies revealed a large left subfrontal mass with extension into the frontal and ethmoid sinuses and the nasal cavity. The patient underwent both a bifrontal transbasal craniotomy and a transnasal approach for an attempt at total resection of both the intradural and extradural components of the MPNST. The patient was treated postoperatively with radiation therapy, and had no evidence of recurrence at her follow-up examination 1-year after treatment. Subfrontal PNSTs are extremely rare and usually benign. The specific cell and nerve of origin for these tumors remains unknown. Our case shows that these rare lesions can present as a malignant variant and thus require aggressive surgical and postoperative management to provide long-term tumor control.- - - - - - - - - - ranking = 3keywords = nerve (Clic here for more details about this article) |
7/16. Rare first symptoms of multiple sclerosis.The most frequent first symptoms of multiple sclerosis are the following: sensory symptoms, optic neuritis, motor and cerebellar syndromes. Three female patients have been diagnosed with multiple sclerosis on the basis of Poser's criteria. The onset of the disease was manifested in these cases with non-typical and rare symptoms. Patient 1, a woman, aged 24. The first symptom of the disease was an isolated lesion of nerve VI on the right side. Patient 2, a women, aged 30. The first symptom of the disease was acute pain localised within the area of the lumbar-sacral spine. Patient 3, a woman, aged 43. The first symptom of the disease was loss of taste and smell.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
8/16. Moebius syndrome in kallmann syndrome.A girl born with congenital paresis of cranial nerves III, IV, and VII (Moeblus syndrome) subsequently developed a progressive peripheral neuropathy. There was suggestive evidence of a familial neuropathy with autosomal dominant inheritance in three family members. The patient also had hypogonadotrophic hypogonadism and anosmia (kallmann syndrome).- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
9/16. Generalized argyrosis in man: neurotological, ultrastructural and X-ray microanalytical findings.Generalized argyrosis can produce a number of abnormalities, including skin discoloration, liver and kidney dysfunction. We describe a patient with generalized argyrosis following long-term self-treatment with oral silver intake, in whom skin discoloration, progressive taste and smell disorders, vertigo and hypesthesia were observed. These findings were confirmed by chemosensory tests and electrophysiological investigations. The development of hypogeusia was assessed by subjective tests, while the progression of hyposmia was followed by recording olfactory evoked cortical potentials. light and electron microscopy of tissue samplings demonstrated electron-dense mineral deposits in basal membranes, in macrophages, in the perineurium of peripheral nerves, along elastic and collagenous fibers, and in necrotic cells of the oral submucosa. silver and sulfur deposits in affected tissues could be defined by X-ray microanalysis. The quantitative ratio between silver and sulfur in involved tissues was similar to that of an inorganic silver-sulfide (Ag2S) standard. The minute increase in the sulfur content when compared to the inorganic standard suggested a sulfur containing organic matrix of the tissue precipitates. Our findings indicate that the affinity of silver for membrane and neuronal structures and the deposition of silver as an insoluble compound (Ag2S) induce the progression of clinical disease.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
10/16. Pituitary changes in Kallmann's syndrome: a histologic, immunocytologic, ultrastructural, and immunoelectron microscopic study.Pituitary cytology was studied in a man with untreated Kallmann's syndrome who died at the age of 61. All the adenohypophyseal cells were normal except the gonadotrophs. The identifiable gonadotrophs were scanty and had few and small secretory granules, which gave a weak positivity for beta -follicle-stimulating hormone (FSH) and beta -luteinizing hormone (LH). The tests showed marked hypogenesis, while the adrenals and the thyroid were normal. In the hypothalamus, the lateral tuberal nuclei were undeveloped, and the nucleus subventricularis exhibited nerve cell hypertrophy. The morphologic findings are in accord with the results of endocrine investigations, which showed that the hypogonadism was due to a failure in the secretion of luteinizing hormone-releasing hormone.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
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