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Biomedical subjects

A Visot

Publications and source records attributed to A Visot.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Prolactin microadenoma in men. Study of 14 cases].

Macroprolactinomas have been well documented in men over the past several years. By contrast, to the best of our knowledge, there have been no reports of microprolactinomas in men. We describe here 14 cases of microprolactinomas occurring in male patients (14 to 53 years old) and discovered on the basis of endocrine symptoms. Nine patients complained of impotence and/or decreased libido, 8 had gynecomastia with or without galactorrhea, 1 had undergone incomplete puberty. All patients had hyperprolactinemia (225 +/- 65 micrograms/l, mean +/- SEM, N less than 13 micrograms/l); plasma testosterone levels were low in 9 (162 +/- 33 ng/dl, mean +/- SEM; N = 308 - 876 ng/dl), while plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels and their responses to LH-releasing hormone (LHRH) were normal in all cases. Among the 14 patients, 12 had no hypopituitarism and 2 had only partial corticotrope insufficiency; none had visual disturbances and only one complained of headaches. The sella turcica was normal in size and shape in 2 cases but a double floor and/or a thinner part of the floor was observed in 12. CT scan of MRI demonstrated in all cases an intrasellar microadenoma with a mean size of 7 mm (range, 3 to 10 mm) and no preferential localization. One patient was treated with bromocriptine, while the others underwent surgery via the transsphenoidal route. Immunocytochemistry demonstrated immunoreactive-prolactin (IR-PRL) cells in all the adenomas. Surgery resulted in normalization of plasma PRL in 11 of the 13 patients and in lowering PRL levels in the others 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Apparently silent somatotroph adenomas.

We describe here 9 patients with somatotroph adenomas associated with mild features of acromegaly and basal plasma GH levels in the normal range. In 5 women and 4 men, 26 to 61 yrs old, the diagnosis of prolactinoma or non-secreting pituitary adenoma had been previously made on the basis of amenorrhea-galactorrhea or tumoral symptoms. However, they had discrete signs of coarsening of the facial features and moderate but evolutive changes of hand and foot sizes. Basal GH levels were in the normal range (0.4 to 4.5 micrograms/l, N less than 5 micrograms/l) but unaffected by oral glucose and insulin tolerance tests while IGF-I concentrations were elevated in all the cases (range 1.7 to 5.8 U/ml, N: 0.37-1.41 U/ml). Plasma PRL concentrations were elevated in 5 patients (range 16 to 80 micrograms/l, N less than 13 micrograms/l in men and N less than 19 micrograms/l in women). The 9 patients had a macroadenoma with an extrasellar extension in 8 of them and all were operated on by the transsphenoidal route. Immunocytochemical studies demonstrated IRGH-cells in all the adenomas and IRPRL-cells in 5 of them. Electron microscopic analysis of 3 tumors showed that the secretory granules were sparse and the Golgi apparatus poorly developed. Molecular biology of 7 tumors showed the presence of small amounts of GH mRNA. This result was in agreement with the morphological aspect, suggesting a low rate of GH synthesis. Thanks to these different approaches the diagnosis of silent somatotroph adenoma should sometimes be reconsidered.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1989

[Stereotaxic treatment in Parkinson's disease].

For the stereotactic treatment of Parkinson's disease, the target is usually located in the thalamus; this point is related to nearby structures (third ventricle). Then the position is controlled by electrophysiological recordings. The lesion of the target results in permanent suppression of the contralateral tremor and/or rigidity but it changes neither the course of the disease nor the akinesia. Owing to the risk of dysarthria with bilateral procedures, the main indication for surgery is parkinsonism with unilateral tremor or rigidity. Particularly interesting for the future are the possibilities of stimulation through implanted chronic electrodes.

Humans↗
PubMed1986

[Treatment of abnormal movements by thalamic lesions].

Thalamic targets in the treatment of involuntary movements include the lateral and usually the intermediary ventral nuclei. Destruction of their afferents in Forel's fields provides the same therapeutic result but the size of the lesion must then be very small due to the proximity of essential structures, particularly corpus Luysi. Efficacy of treatment depends partly on the aetiology of the involuntary movement (and thus from the indication for surgery) and also on the technical possibilities of electrophysiologic mapping. The true dystonic element of the involuntary movement is usually little improved whereas tremors of all types are improved or suppressed. Essential tremor, familial or not, of large amplitude and very disabling, is an ideal indication for stereotaxic surgery when it presents as intention tremor. In Parkinson's disease, the treatment is effective against tremor and rigidity but akinesia is unaltered and the progressive course of the disease uninterrupted. Indications for surgery have become rare since the availability of L-dopa, perhaps too rare for the slowly progressive forms with predominant tremor poorly relieved by dopa-therapy, surgery has a curative and probably preventive effect on the involuntary movements of limbs induced by this treatment. Suppression of post-traumatic tremor and that due to multiple sclerosis is dependent on various factors: electrophysiologic precise mapping of the target since "electrical silences or holes" exist that disturb or prevent collection of evoked potentials or spike activity; multiple neurologic lesions that may be worsened by an additional thalamic lesion; finally residual cerebellar disturbance unmasked by the suppression of tremor, a poor "functional" result despite a good operative result.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Injuries↗
PubMed1985

Surgical treatment of prolactinomas. Short- and long-term results, prognostic factors.

All 347 patients surgically treated for a prolactinoma from January 1, 1976 to December 31, 1982, in the neurosurgical ward of Foch Hospital, were retrospectively studied. The frequency of postoperative normalisation of plasma prolactin (PRL) depends on prolactinoma size, preoperative PRL level, duration of first clinical symptom, previous oestroprogestative contraception, and adenoma necrosis. Postoperative PRL values were normalized in 75% of small prolactinomas (grade 0, 1 or 2) with preoperative PRL values less than 200 ng/ml, and clinical duration less than 5 years (n = 102). There was no operative death and minor morbidity (2.7%). Among the 96 patients with postoperative PRL normalisation, operated between 1976 and 1979, 70 were followed up for an average time of 4.4 +/- 0.2 years. 17% of patients had hyperprolactinemia recurrence with a delay of 1.5 +/- 0.4 years. Postoperative PRL levels near the upper normal limit, and weak PRL response to TRH tests were found to be unfavourable prognostic factors for hyperprolactinemia recurrence. Pregnancy did not increase the risk of recurrence, but could reflect genuine long-lasting remission. Selective adenomectomy remains an interesting treatment for prolactinoma, particularly if the adenoma is small, recent and with PRL moderately increased. The frequency of postoperative PRL normalisation after surgery is less than with bromocriptine, but surgery is the only treatment able to achieve a definitive cure with a low iatrogenic risk.

Adenoma↗
PubMed1982

Hyperostosing meningiomas of the sphenoid ridge--clinical features, surgical therapy, and long-term observations: review of 49 cases.

Thirty-three patients with en plaque, 9 with en masse (but with extensive bone involvement), and 7 with recurrent hyperostosing meningiomas of the sphenoid ridge were operated on. All patients underwent large extradural resection of the base of the skull as well as extirpation of the intradural tumors or adjacent plaques. The periorbita was involved in 13 patients (26.5%). Seventeen patients (34.7%) needed reconstruction of the base of the skull. This was achieved with autogenous bone grafts. In all but 3 patients, invasion of the bone by meningiomatous tissue was demonstrated histologically. Operative mortality was 4%. Total removal was possible in 91% of the patients with meningiomas located at the pterion or middle third of the sphenoid ridge. More difficult was the total removal of meningiomas of the inner third or of the entire sphenoid ridge (47%). However, long-term results have proved to be satisfying. Early surgical therapy should always be considered as the treatment of choice for such meningiomas.

Adolescent↗
PubMed1980

Endocrine outcome after transsphenoidal adenomectomy for prolactinoma: prolactin levels and tumor size as predicting factors.

The level of prolactin in the serum was determined pre- and postoperatively in 90 patients who were operated upon transsphenoidally for prolactin-secreting pituitary adenomas. Twenty-three had microadenomas and 67 had macroadenomas. Those patients who were cured had a distinctly lower mean prolactin level (about 200 ng/ml or less) than those who were not cured. Of those patients whose adenomas were larger than 10 mm in diameter, only 39% were cured. The relationship between prolactin levels and tumor size and the return of menses and cure is discussed.

Adenoma↗
PubMed1980

[Optic chiasm gliomas (author's transl)].

A follow up study of 40 cases of optic chiasm gliomas is presented. Histological examination was obtained in 26 cases. All were bipolar spongioblastomas. Four of these were optic nerve gliomas, 17 chiasmatic gliomas and 19 invasive optohypothalamic tumors. The main clinical features are reviewed with special attention to endocrine disorders, including precocious puberty and diencephalic emaciation. Neurofibromatosis was present in 30%. Diagnostic difficulties are outlined, especially in chiasmatic tumors without optic nerve involvement: event with C T scan, the differential diagnosis with ectopic pinealomas, craniopharyngiomas and primary hypothalamic tumors, may be difficult. The operative mortality was 12% (3/25). All but one, had radiotherapy either alone or post operative. All four of the patients with unilateral optic nerve gliomas have a normal C T scan more than 10 years after treatment. Of the 17 patients with chiasmatic gliomas, 14 are alive with normal C T scan in 2 cases, and with reduction in size of the tumor in 7. Eleven of 19 patients with invasive gliomas are alive with diminished size of the tumor in 7. Improvement in visual acuity, reduction in size of tumor mass, persistent increase in size of non irradiated tumor and lack of recurrence of optic nerve glioma even with histological proven chiasmatic involvement is taken as evidence of the effect of radiotherapy. The sub frontal approach is emphasized for optic nerve and optic chiasm tumors: it provides direct surgical verification with the opportunity for complete removal, large biopsy, decompression of the optic foramina or cyst removal. Regarding secondary endocrine disorders, radiotherapy is discussed in children. If necessary it must be managed under careful evaluation of endocrine status, principally growth function.

Adolescent↗
PubMed1977

[Attempt at explaining decompensation of hydrocephalus by modifications of reticular activity].

A correlative study is done between observation of cases of shunted hydrocephalus with mesencephalic signs such as Parinaud's syndrome and a multiunitary recording of mesencephalic and bulbar reticular formation activities during acute and chronic intracranial hypertension in cats. Clinical and experimental data are first separately analysed and then superimposed. This results in analysing the evolution of such intracranial hypertension in three stages: first stage of "tolerance" with minimal clinical signs and no change of reticular activity; second stage of "uncompensation" when mesencephalic signs appear and with increased mesencephalic activity and unchanged bulbar activity; third stage of "exhaustion" where can be noted disorders of consciousness, decerebration fits, and cardiorespiratory disorders; mesencephalic activity falls down to lower levels than basal ones, bulbar activity increases first and then also decreases rapidly. This suggests a mechanism of exhausting stocks of monoamines but also of change of the local cerebral blood flow. Increase and then fall of the reticular activity may be the general way, even without any herniation, of evolution of any intracranial hypertension of traumatic or tumoral origin.

Cerebrospinal Fluid Shunts↗
PubMed1976

Diagnosis of pinealoblastomas by positive response to cobalt-therapy.

Surgical excision of pineoblastomas is considered dangerous, and relief of raised intracranial pressure by shunting followed by cobalt therapy is the preferred treatment. Demonstration by pneumoencephalography of tumour shrinkage after therapy confirms the diagnosis of pineoblastoma. Failure of the tumour to become smaller indicates a different pathology which calls for a surgical approach, except in the case of a brain stem tumour.

Adolescent↗