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PubMed2002

Management of recurrent pituitary cysts with pituitary-nasal drain.

Pituitary cysts are usually craniopharyngiomas or remnants of Rathke's cleft. Histologically craniopharyngiomas are lined by stratified squamous epithelium whereas Rathke's cleft cysts are lined by cuboidal or columnar epithelium. The management of pituitary cysts remains difficult because of the risks associated with attempts at complete removal and the chances of recurrence after inadequate resection. We describe 3 cases of cystic craniopharyngiomas and one case of Rathke's cleft cyst which recurred after surgery and were subsequently managed successfully with pituitary-nasal drains.

Adult↗
PubMed2000

Visual electrophysiology in children with tumours affecting the visual pathway. Case reports.

In 9 children (8-14 years of age) with orbital, suprasellar or postchiasmal tumours, visual loss was studied by visual electrophysiology in relation to ophthalmologic and neuroimaging findings. Pattern electroretinography (PERG) and pattern visual evoked potentials (PVEP) to full and half-field pattern-reversal stimulation were recorded and PERG and PVEP changes were related to the tumour location. PERG wave P50 attenuation was found associated with the central retinal dysfunction in the child with orbital rhabdomyosarcoma; PVEP wave P100 delay was associated with the optic nerve dysfunction in a child with retrobulbar chondrosarcoma and in a child with optic nerve glioma; PVEP wave P100 asymmetry was associated with the crossed fibers dysfunction in a child with hypothalamic germinoma, and PVEP wave P100 uncrossed asymmetry was associated with postchiasmal dysfunction in children with postchiasmal tumours (one with pilocytic astrocytoma and two with angioma). On the other hand, normal PERG suggested that there was no central retinal dysfunction in a child with pleomorphic adenoma of the lacrimal gland, and normal PVEP to full and half-field stimulation excluded visual pathway dysfunction at the chiasm in a child with suprasellar arachnoidal cyst. Follow-up was useful in indicating whether visual dysfunction was progressive or not. We conclude that PERG and PVEP findings contributed to understanding whether the dysfunction originated was at the retina, in the optic nerve, chiasm or postchiasmal pathway.

Adolescent↗
PubMed1992

Preserved figure-ground segregation and symmetry perception in visual neglect.

A central controversy in current research on visual attention is whether figures are segregated from their background preattentively, or whether attention is first directed to unstructured regions of the image. Here we present neurological evidence for the former view from studies of a brain-injured patient with visual neglect. His attentional impairment arises after normal segmentation of the image into figures and background has taken place. Our results indicate that information which is neglected and unavailable to higher levels of visual processing can nevertheless be processed by earlier stages in the visual system concerned with segmentation.

Aged↗
PubMed1994

Mapping motor representations with positron emission tomography.

Brain activity was mapped in normal subjects during passive observation of the movements of an 'alien' hand and while imagining grasping objects with their own hand. None of the tasks required actual movement. Shifting from one mental task to the other greatly changed the pattern of brain activation. During observation of hand movements, activation was mainly found in visual cortical areas, but also in subcortical areas involved in motor behaviour, such as the basal ganglia and the cerebellum. During motor imagery, cortical and subcortical areas related to motor preparation and programming were strongly activated. These data support the notion that motor learning during observation of movements and mental practice involves rehearsal of neural pathways related to cognitive stages of motor control.

Adult↗
PubMed1994

Visual field interpretation with a personal computer based neural network.

The Computer Assisted Touch Screen (CATS) and Computer Assisted Moving Eye Campimeter (CAMEC) are personal computer (PC)-based video-campimeters which employ multiple and single static stimuli on a cathode ray tube respectively. Clinical studies show that CATS and CAMEC provide comparable results to more expensive conventional visual field test devices. A neural network has been designed to classify visual field data from PC-based video-campimeters to facilitate diagnostic interpretation of visual field test results by non-experts. A three-layer back propagation network was designed, with 110 units in the input layer (each unit corresponding to a test point on the visual field test grid), a hidden layer of 40 processing units, and an output layer of 27 units (each one corresponding to a particular type of visual field pattern). The network was trained by a training set of 540 simulated visual field test result patterns, including normal, glaucomatous and neuro-ophthalmic defects, for up to 20,000 cycles. The classification accuracy of the network was initially measured with a previously unseen test set of 135 simulated fields and further tested with a genuine test result set of 100 neurological and 200 glaucomatous fields. A classification accuracy of 91-97% with simulated field results and 65-100% with genuine field results were achieved. This suggests that neural networks incorporated into PC-based video-campimeters may enable correct interpretation of results in non-specialist clinics or in the community.

Diagnosis, Computer-Assisted↗
PubMed1999

Incidentally discovered pituitary lesions: high frequency of macroadenomas and hormone-secreting adenomas - results of a prospective study.

OBJECTIVE: With increasing use of computed tomography and magnetic resonance imaging, pituitary adenomas are being discovered incidentally with increasing frequency. However, limited data are available concerning the clinical importance and natural history of such 'incicentalomas'. We have undertaken a prospective study to investigate changes in adenoma size and endocrine and visual function in patients with incidentally discovered intrasellar masses. PATIENTS AND METHODS: Our study included 67 patients with incidentalomas of the pituitary gland during a 5-year period (1992-96). 50 of these patients were followed up prospectively over a mean period of 2.7 years. Initially, all patients underwent endocrine testing and ophthalmological examinations as well as magnetic resonance imaging or computed tomography scans. These investigations were repeated after 3 months and then annually. RESULTS: 42 (62.7%) out of 67 patients with incidentalomas had microadenomas whereas 37.3% had macroadenomas. Macroadenomas were found more frequently in men (52.2%). Visual field defects could be documented in 4.5% of the patients. Partial deficiency of anterior pituitary function was present in 14.9%. Eight patients (11.9%) had prolactinomas. An increase in adenoma size was detected in 3.2% of the microadenomas and in 26.3% of the macroadenomas within the follow-up period. CONCLUSION: Macroadenomas and hormone secreting adenomas are not uncommon in patients with pituitary incidentalomas. Macroadenomas should be closely monitored for tumour enlargement. All patients should undergo biochemical assessment and ophthalmological examination, since endocrine dysfunction or visual field defects may be present at the time a pituitary incidentaloma is detected.

Adenoma↗
PubMed2002

Traumatic chiasmal syndrome: a series of 19 patients.

PURPOSE: To present a clinical series of 19 patients with traumatic chiasmal syndrome. METHODS: A retrospective study was performed. This included all patients with traumatic chiasmal syndrome seen in the neuro-ophthalmology clinic at the Royal Adelaide Hospital between January 1970 and January 2000. RESULTS: Of the 19 study patients, most were young males involved in motor accidents. Two-thirds had skull fractures. Three-quarters of patients had a final visual acuity of 6/12 or better in at least one eye. Ten patients had a complete optic nerve palsy. The incidence of diabetes insipidus in this study was 37%. The incidence of cranial nerve lesions, hypopituitarism, carotid cavernous fistula, and other deficits were documented. Magnetic resonance imaging and surgical findings were consistent with known mechanisms of chiasmal injury. CONCLUSIONS: Trauma is a rare cause of chiasmal syndrome. Patients with bitemporal field defects should be questioned about prior head injury. In the acute setting, magnetic resonance imaging is the most useful investigation. The treating practitioner should anticipate and treat associated endocrine, ocular motility, and other disorders. Mechanisms of damage to the optic chiasm after trauma include direct tearing, contusion haemorrhage and contusion necrosis. These mechanisms should not be considered mutually exclusive. Unilateral temporal hemianopia with a fellow blind eye is not necessarily the result of chiasmal disruption.

Adolescent↗
PubMed2000

Disseminated infection due to Encephalitozoon cuniculi in a patient with AIDS: case report and review.

OBJECTIVE AND METHODS: Infections due to microsporidia are increasingly recognized as opportunistic infections in patients with AIDS. We describe here a case of disseminated infection due to Encephalitozoon cuniculi and review the literature on this microsporidial infection. RESULTS: All 12 patients reported in the literature had AIDS and nine presented with disseminated infection involving the kidneys, sinuses, lungs, brain and conjunctiva. Asymptomatic infection was seen in three patients. Microsporidia were detected by light microscopy examination of urine samples in all the cases. Species identification was performed by various genotypic methods or transmission electron microscopy. Eight of 12 patients who received albendazole therapy experienced clinical improvement with documented clearance of spores in five of these eight patients. Two patients relapsed. CONCLUSIONS: E. cuniculi infection should be considered in severely immunocompromised HIV-infected patients with multi-organ involvement and fever, especially when renal failure is present. Microsporidial spores are usually seen in urine samples and in the involved organ. Albendazole therapy seems to be effective.

AIDS-Related Opportunistic Infections↗
PubMed2003

[Bilateral spontaneous development of a frontal sinus pyocele--a rare diagnosis].

Due to the length and the narrowing of the sinus draining passage, mucoceles are typically located within the frontal sinus. This case report describes the pathology of a patient with bilateral formation of pyoceles of the frontal sinus without the history of trauma, sinus operation or nasal pathology. The patient visited an ophthalmologist and reported a slowly increasing visual loss and protrusion of the left bulbus in the course of one year. Coronal CT scan showed bilateral soft tissue densities within the frontal sinus with arrosion of the floor on the left side. Extranasal frontal sinus surgery with ethmoidectomy (Ritter-Jansen and Uffenorde mucosal plasty) was performed. Intraoperative view demonstrated bony defects of the floor and the posterior wall of the frontal sinus.

Aged↗
PubMed1983

[Palinopsia (visual preservation) and cerebral polyopia--clinical analysis and computed tomographic findings].

The positive visual phenomena of palinopsia and cerebral diplopia/polyopia have only rarely been recorded. The complex phenomenology (visual/oculomotor) is described based on two cases with right occipital infarcts and a review of the literature. In each case demonstrated CT revealed a small area of decreased density confined to the border region of the right area striata causing homonymous field defects. The phenomena are discussed in the light of what is known about visual after-images and hallucinations. The underlying neural mechanisms are still unknown; a defective cortical visual information processing is suggested.

Aged↗
PubMed1998

[Suprasellar meningioma. A disease still frequently diagnosed too late].

BACKGROUND AND OBJECTIVE: Suprasellar meningioma continues to be diagnosed very late after the onset of first eye symptoms. This study was aimed at demonstrating the effect of delay on the long-term visual loss. PATIENTS AND METHODS: In the course of a retrospective study all 53 consecutive patients operated on for suprasellar meningioma from 1982 to 1991 were contacted (47 women, 6 men; average age 49.5 years) 46 of the 49 surviving consented to the follow-up investigation. The extent of preoperative visual loss, tumour size, presence of optic nerve atrophy and duration of visual loss, data that provide an indirect measure of how soon the correct diagnosis was made, were analysed with regard to their effect on long-term ophthalmological results. RESULTS: The mean period elapsing from onset of first visual symptoms to the definitive diagnosis of suprasellar meningioma was 22.3 months. The data showed that the long-term results were the worse the later the diagnosis was made. CONCLUSIONS: The commonly very late diagnosis of suprasellar meningioma as cause of visual loss is an international problem and is presumably due to the low incidence of the tumour (1-2 cases per 1 mill. population per year). If long-term results are to be improved, primary care doctors must be made aware of the differential diagnosis of visual loss caused by pressure from a tumour.

Adult↗
PubMed1991

[Endoscopically-controlled endonasal orbital decompression in malignant exophthalmos].

In 6 patients with endocrine ophthalmopathy, indications, surgical technique and results of the endoscopic controlled endonasal orbital decompression are described in comparison to the common surgical procedures. When medical and radiation therapy fail, indications for decompression are a) loss of visual acuity or visual field defects, b) increasing strabismus, c) severe keratopathy due to eyelid retraction. The endoscopic-controlled endonasal surgical decompression technique is proceeded in three steps. First, an endonasal ethmoidectomy with resection of the middle turbinate is performed and the medial wall of the maxillary sinus is widely opened. Second, the medial and inferior wall of the orbital walls are removed, preserving the infraorbital nerve. In the last step, the periorbital area is incised and the orbital fat herniates. The advantages of this procedure consist in the absence of exterior scars and the known morbidity of a Caldwell-Luc antrotomy. The results were documented by computed tomographic scans (CT), magnetic resonance imaging (MRI), Hertel measurements, evaluation of ocular motility and ophthalmoscopy. An average of 3-4 mm improvement in Hertel-measurements could be reached. All patients had a postoperative improvement of visual acuity. 2 patients developed more significant diplopia postoperatively, whereas in all other patients ocular motility either improved or rested unaffected. Therefore, the endoscopic controlled endonasal procedure allows to obtain comparable results to the common extranasal and transantral procedures without the disadvantages of the latter.

Aged↗