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Biomedical subjects

C Raitta

Publications and source records attributed to C Raitta.

At least 73 records · Page 4Linked to original sources
PubMed1982

Changes in the electroretinogram and visual evoked potentials during general anaesthesia using enflurane.

Fourteen female patients 27.7 +/- 10.0 years of age were studied by electrophysiological means before and during general anaesthesia. A mixture of thiopentone sodium, enflurane and nitrous oxide was used for anaesthesia. Electroretinogram (ERG) and visual evoked potentials (VEP) were recorded with electrodes placed on the lower lid and scalp and an averaging technique was used. The recordings were made under standard conditions with the pupils dilated, the eyes adapted to the dark and after 15-20 min stable anaesthesia. The latency of the a-wave did not change, whereas the b-wave was delayed (P less than 0.01). The amplitude of the a-wave tended to decrease; however, an increase of amplitude was also present. Therefore the change was not significant. The b-wave was unchanged. Changes induced by anaesthesia were often noted in the shape of P130, where a change from V to W-form took place or the reverse. The latencies of the late components N180 and P220 were increased during anaesthesia (P = 0.006 and P = 0.001, respectively). No statistically significant change occurred in the N180 and P220 amplitudes. The amplitudes of N60 and P130 became smaller (P = 0.002 and P = 0.0003, respectively) during anaesthesia. The effect of enflurane on the components of the VEP seems to indicate a cortical site of action.

Anesthesia, General↗
PubMed1982

A variant of Jansky-Bielschowsky disease.

A series of 18 patients with Jansky-Bielschowsky disease is presented. Two children only showed the classical features of the disorder, whereas the remaining 16 differed from the cases previously published in the following respects. Clinically: later onset of age, early onset of visual failure and an intermediate course of the disease. Neurophysiologically: spikes in response to intermittent stimulation appeared by the age of 7-8 years and disappeared after 11 years. The visual evoked response was extinct at an advanced stage of the disorder. Morphologically: accumulation of cytosomes with curvi-linear and fingerprint profiles in solid tissues, but lymphocytes showed no storage material. Electron microscopy of the lymphocytes revealed nothing abnormal.

Child↗
PubMed1982

Mulibrey nanism, an autosomal recessive syndrome with ocular involvement.

Mulibrey nanism is a rare autosomal recessive condition characterized by a growth failure of pre-natal onset and several associated dysmorphic features. On ophthalmoscopy the optic disc and macula have a normal appearance while the midperiphery and more peripheral areas have revealed hypopigmentation and pigment scattering. By fluorescein angiography areas of focal choroidal hypoplasia have been noted. Histopathological examination of a typical case revealed atrophy of the corneal epithelium and thickening of the Bowman's membrane. The optic nerve and the macula appeared normal while the midperiphery showed focal choroidal hypoplasia with marked atrophy of the retina and of the pigment epithelium. Occasional drusen were also noted in this area. The findings do confirm the hypothesis that the choroidal changes represent one further manifestation originating from mesodermal tissues in these patients.

Abnormalities, Multiple↗
PubMed1982

Ocular findings in myotonic dystrophy.

Thirty-three patients (20 female and 13 male patients aged 13 to 52 years) with myotonic dystrophy (MyD) were studied. Ophthalmologic examination included tonography, electroretinography (ERG), and fluorescein angiography. Thirty patients had bilateral cataracts of the subcapsular type, two patients had aphakia in both eyes, and one patient had clear lenses. Hypotonia (intraocular pressure, less than or equal to 10 mm Hg) was a common finding in 19 of 66 eyes. The mean IOP was 11.8 mm Hg for the whole series and the mean outflow facility was c = 0.34 cu mm/min. Focal signs of retinouveal affection were present in nine patients. Clinically, they appeared as acquired lesions affecting the retina, pigment epithelium, and choroid. One patient was found to have an outburnt panuveitis. The ERG was normal in 11 patients, subnormal in five patients, and isoelectric in four patients. An extinguished ERG did not correlate to clinical findings of known hereditary retinal or choroidal dystrophies. The ophthalmologic findings may be explained by a primary defect related to the cell membrane.

Adolescent↗
PubMed1981

Dominant progressive cone-rod dystrophy.

The report describes a Finnish family in which retinal lesions associated with a considerable visual loss have been found in 19 probands in 5 consecutive generations. The progressive cone-rod dystrophy diagnosed in the probands shows an autosomal dominant mode of inheritance. The onset of the disease was noticed in most of the probands early during the first decade of life. In the young diseased probands the fundal lesions showed the pattern found in pure cone dystrophies. Elder probands, however, had lesions and dysfunctions indicating an obvious rod involvement in addition to the cone dystrophic pattern. The fundal lesions included very extensive pigmentation in most of the elder probands with the disease. In addition to the retinal lesions, considerable astigmatism and lens opacities at the level of the posterior capsule were found in a great proportion of the probands.

Adolescent↗
PubMed1981

Impaired color discrimination among viscose rayon workers exposed to carbon disulfide.

A possible effect of chronic carbon disulfide exposure on the optic nerve was studied by giving the Farnsworth Munsell 100-Hue Test for color discrimination to 62 exposed and 40 nonexposed men. Carbon disulfide exposure did not relate to specific pattern defects in color discrimination, but impaired color discrimination occurred significantly more often in the exposed group than among the referents. The abnormal findings suggest an impairment in the receptiveness of the ganglion cells or demyelination of the optic nerve fibers.

Adult↗
PubMed1980

[The significance of ciliary circulation in the development of iris neovascularisation (author's transl)].

Three cases of peripapillary choroidal filling defects demonstrated by fluorescein angiography are presented. In two cases the defect was interpreted as an occlusion of a posterior ciliary artery. One of these patients had neovascularization of the iris and ischemia of the upper half of the retina. Later a contralateral hemiplegia developed. The other patient had no other known vascular disease of the eye except occlusion of the posterior ciliary artery by giant cell arteritis. One patient had underfilling of the peripapillary choroid which was interpreted as insufficiency of the ciliary circulation; he had neovascularization of the iris, a nonperfused area in the retina and extensive microangiopathy due to arterial hypertension. It was concluded that ciliary hypoxia is the cause of iris and papillary neovascularization. Occlusion of one posterior ciliary artery is not enough to decompensate anterior segment circulation, unless other high risk factors such as carotid insufficiency or arterial hypertension are present.

Aged↗
PubMed1979

Changes in the electroretinogram and visual evoked potentials during general anaesthesia.

Ten patients (one male and nine females), aged 33.2+/-12.0 years, were given electrophysiological studies before and during general anaesthesia. A mixture of thiopentone sodium, halothane, and nitrous oxide was used for anaesthesia. Electroretinogram (ERG) and visual evoked potentials (VEP) were recorded with scalp electrodes, and an averaging technique was used to improve signal-noise ratio. The recordings were made under standard conditions 15 to 20 min after induction of the anaesthesia. The amplitudes of the a- and b-waves of the ERG were significantly diminished whereas their latencies remained unchanged. The peak-to-peak amplitudes of the early components N1 and P2 of the VEP were significantly lowered, and the latencies of N0, P1, and N1 were prolonged by anaesthesia. These modifications are suggested to reflect metabolic changes in the sensitive layers of the retina and in the optic tract.

Adult↗
PubMed1979

n-Hexane-induced changes in visual evoked potentials and electroretinograms of industrial workers.

Visual evoked potentials (VEPs) and averaged extraocular electroretinograms (ERGs) were recorded from 15 workers occupationally exposed to n-hexane for 5-21 years and from 10 healthy control persons. The amplitude of the VEP components was clearly smaller among the exposed subjects with the exception of N0, which tended to be larger. In addition, the latencies of P1 and N1 were longer among the exposed workers, while that of P2 was slightly shorter. The peak-to-peak amplitude of the ERGs was also diministed among the exposed subjects. The changes were interpreted to indicate cerebral dysfunction, probably conduction block in intracerebral axons. n-Hexane is an aliphatic hydrocarbon found in gasoline and used in various industrial applications. It has been shown to cause axonal neuropathy of the dying-back type in both experimental animals and humans. According to the present findings the central nervous system is alos susceptible to the toxic effects of n-hexane.

Adult↗
PubMed1979

[Butterfly-shaped dystrophy of the macula with absent pre-beta-fraction of the electropherogram of the serum lipoproteins (author's transl)].

A case of butterfly-shaped dystrophy of the macula is described. Clinical and electrophysiological data are compared with those of 11 cases described in the literature. An aberrant electropherogram of the lipoproteins examined at two different laboratories was found to be present. The serum lipoproteins showed total lack of the pre-beta-fraction. Two children of the patient were examined, too. They showed minimal macular changes which however did not justify the diagnosis of butterfly-shaped dystrophy. Their pre-beta-lipoprotein fractions of the electropherogram were below the Finish standards. The proband is the first case of butterfly-shaped macular dystrophy described from Finland and therefore it was not possible to control the laboratory findings on other cases. The absence of the pre-beta-lipoprotein fraction might be an important feature of butterfly-shaped dystrophy of the macula.

Adolescent↗
PubMed1978

N-hexane maculopathy in industrial workers.

A neuro-ophthalmologic examination, including fluorescein angiography and colour discrimination tests, was made of 15 workers (age range 30--65 years, mean 45.8 years) exposed to n-hexane (range of exposure 5--21 years) during vegetable oil extracting and adhesive bandage manufacturing. Visual acuity, visual fields, intraocular pressure, and biomicroscopical findings were normal. Ophthalmocopy revealed delicate macular changes in 11 or the 15 subjects. One subject had a history of central serous retinopathy in one eye. The macular changes consisted of an orange-like ophthalmoscopic appearance and a decreased macular lustre. Subtle defects of the pigment layer were present in the fluorescein angiography. Defective colour discrimination was found in 12 of the 15 subjects, one of whom had congenital deuteranopia. Colour defects were of the acquired type, mainly in the blue-yellow spectrum. Damage to the receptor lipids is suggested as the pathomechanism of the maculopathy found in this study.

Adult↗
PubMed1978

The management and prognosis of gliomas of the optic pathways in children.

A follow-up study was made of 24 children with gliomas of the optic pathways. In gliomas restricted to one optic nerve, total excision should be performed. The prognosis is excellent. Radiotherapy is not indicated. In gliomas of the anterior chiasma a biopsy should be taken; occasionally partial removal is indicated. The prognosis is good. Radiotherapy is indicated only if the follow-up shows a progression in the visual signs. In most cases the growth of the tumour seems to be arrested. The vision remains stable, and most patients have a useful degree of vision in at least one eye. In gliomas of the posterior chiasma with hypothalamic signs the prognosis is poor. A biopsy and radiotherapy are indicated. Occasionally, long remissions are seen.

Adolescent↗
PubMed1978

Pituitary function after pituitary apoplexy.

Pituitary function was studied in nine patients who had recovered from pituitary apoplexy. All the patients recovered spontaneously; none required immediate surgery. Four of the patients had acromegaly, two had pituitary-dependent Cushing's syndrome, and a "functionless" pituitary adenoma was found in three. Low serum growth hormone concentrations were observed in three patients with acromegaly whereas the concentration remained increased in the fourth one. Of the two patients with Cushing's syndrome, a selective ACTH-deficiency developed in one and Nelson's syndrome appeared with excessive secretion of ACTH in the other. Transient or persistent hypofunction of the anterior pituitary occurred in al patients. Three patients underwent hypophysectomy after respective intervals of three, eight and 12 months after pituitary apoplex. The operation revealed a hemorrhage in one functionless adenoma and a large cyst in another one. In the third patient who had acromegaly, no signs of the pituitary apoplexy were observed at operation.

Acromegaly↗
PubMed1977

Glaucomatocyclitic crisis.

Ten patients with glaucomatocyclitic crisis were examined for glaucoma during the interval. The follow-up period was over ten years. One patient had primary open angle glaucoma and two had suspicion of glaucoma. These findings confirmed our previous concept of an association between glaucomatocyclitic crises and open angle glaucoma. Six patients were examined during acute attacks. Focal segmental ischaemia of the iris of different degree was typical during the attack, later in the immediate postattack phase congestion, leakage and even extreme hypotony were found. Iris angiography during the interval showed generally a rich vascular pattern, and in some cases, tortuous vascular tufts. Stromal atrophy and atrophy of the sphincter were considered secondary to pressure attacks. The role of the abnormal reactivity of the vessels of the ciliary vascular system on the development of acute attacks is discussed.

Adult↗
PubMed1977

Photography of the nerve fiber layer in retinal disturbances.

The diagnostic value of nerve fiber layer photography is assessed. The series comprised 39 patients with various neuro-ophthalmological diseases. Photography of the nerve fibers in the retina is time consuming and requires skill on the part of the photographer. Differences in the papillomacular nerve fiber layer are difficult to distinguish using the present methods. The wasting of nerve fibers could be documented by photography in advanced cases with bitemporal hemianopia, but not in small relative scotomas. Cases with homonymous hemianopia are interesting because lesions in the optic tract can be differentiated from affections of the second neuron on the basis of retinal nerve fiber atrophy. In demyelinating diseases inspection of the retinal nerve fiber layer is of clinical importance and diagnostic changes appear,

Adolescent↗