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Biomedical subjects

P Derome

Publications and source records attributed to P Derome.

At least 19 recordsLinked to original sources
PubMed1992

Thalamocortical diaschisis: positron emission tomography in humans.

To investigate further the relations between cortical energy metabolism and neuropsychological impairment after unilateral thalamic lesion, 55 patients underwent positron emission tomography studies of either cortical oxygen consumption or glucose utilisation, including eight repeat studies, at times ranging from 4 days to 98 months after the onset of the lesion [stroke (n = 44) or stereotaxic VL-Vim thalamotomy performed for movement disorders (n = 11)]. Patients with thalamotomy were also studied preoperatively and the surgery induced a significant fall in cortical metabolism on both sides (more so ipsilaterally); post-operatively the magnitude of the ipsilateral cortex hypometabolism was positively correlated to the severity of global neuropsychological impairment; similar but less significant findings were obtained for the ipsilateral/contralateral cortical metabolic asymmetry. With respect to the whole patient sample, the cortical metabolic asymmetry was initially pronounced, with subsequent monoexponential recovery, in the cognitively impaired study group, but it was only mild and showed no meaningful trend for recovery in the cognitively unaffected study group; yet even soon (< 3 months) after thalamic lesion there was a noticeable overlap of individual asymmetry values among the two study groups. These results lend further support to the view that the neuropsychological impairment that frequently follows unilateral thalamic lesions is reflected in a depression of synaptic activity in both the overlying and the contralateral cerebral cortices. For individual patients, this study also illustrates the potentially misleading nature of the measured cortical metabolic asymmetry with respect to neuropsychological status, especially at late times after lesion, in part because side to side metabolic ratios do not reflect bilateral changes.

Adult↗
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↗
PubMed1991

Pituitary enlargement with suprasellar extension in functional hyperprolactinemia due to lactotroph hyperplasia: a pseudotumoral disease.

Beside the well characterized PRL-secreting adenomas, a wide spectrum of functional hyperprolactinemic states exists. We describe here five women, 21-38 yr old, all suspected of having a PRL-secreting adenoma because of a pseudotumoral appearance of the pituitary on computerized tomographic (CT) scan or magnetic resonance imaging (MRI). Four had oligomenorrhea with or without galactorrhea, one had amenorrhea with galactorrhea, and two complained of infertility. In the same patient, basal plasma PRL levels were variable on different days, sometimes normal (mean +/- SEM, 11.3 +/- 1.5 micrograms/L), sometimes elevated (49 +/- 7 micrograms/L), but in all cases, a PRL response of large amplitude to TRH (6- to 8-fold increase in the basal value) was observed. Basal plasma levels of estradiol were within luteal phase normal values (0.41 +/- 0.13 pmol/L), while progesterone levels were low (1.92 +/- 0.47 nmol/L). CT scan or MRI showed an intrasellar mass with suprasellar extension, suggesting a tumoral process. However, the signal intensity was homogeneous, and on coronal views, the suprasellar extension was pyramidal and symmetrical, and the pituitary stalk was always in the midline. The five patients were operated on by the transsphenoidal route, but no adenoma was found. Surgical biopsies were taken in four cases, and lactotroph hyperplasia, i.e. enlarged cell cords consisting mainly of PRL cells, was found in three of them. One case displayed a continuum between areas of lactotroph hyperplasia and adenomatous PRL cells. We conclude that functional hyperprolactinemia may mimic on CT scan or MRI a PRL-secreting adenoma.

Adult↗
PubMed1989

The effect of somatostatin analogue on chiasmal dysfunction from pituitary macroadenomas.

The long-acting somatostatin analogue SMS 201-995 has been shown to be efficient in the treatment of somatotropic and thyrotropic adenomas. In some cases, it can suppress adenoma secretion and lead to tumor shrinkage. Pituitary macroadenomas are often associated with a vision-threatening chiasmal syndrome. In this series, SMS 201-995 was administered subcutaneously to eight patients with pituitary macroadenomas of various types responsible for severe long-lasting visual defects. An obvious improvement of both visual fields and acuity occurred in six patients, in two of these during the first 4 to 6 hours of treatment; in two patients, gonadotropic adenomas were unresponsive. Maximal improvement (normalization of visual fields in three cases) occurred within 6 to 45 days and was sustained during the 1- to 12-month follow-up period. This effect seems independent of the type of adenoma since the adenomas secreting growth hormone (GH) and thyroid-stimulating hormone and silent corticotropic-secreting adenomas responded as well as did two of the non-functioning adenomas. In one acromegalic patient visual improvement was obtained while the abnormal GH secretion remained unaltered. In all cases but one, no tumor shrinkage could be demonstrated. These data demonstrate that SMS 201-995 can rapidly improve the chiasmal syndrome due to pituitary macroadenoma, and suggest that this effect might be independent of a reduction in tumor volume.

Adenoma↗
PubMed1988

[Treatment of post-neurosurgical diabetes insipidus with desmopressin by intramuscular route].

Desmopressin (DDAVP) is used intramuscularly in the treatment of post operative diabetes insipidus as soon as the condition is diagnosed to ensure continuous replacement of antidiuretic hormone secretion during the first 5 days of therapy. Two successive studies, each involving 15 patients, were conducted. The first study was designed to test the effectiveness and detect the possible side effects of intramuscular DDAVP, while the purpose of the second study was to evaluate the clinical application of the drug. With seven 2 mcg doses of DDAVP, administered 12-hourly by intramuscular injection to patients weighing more than 30 kg, continuous antidiuresis during 96 hours was achieved. This method is simple and effective, but it should not be prolonged beyond that period of time. Moreover, to prevent plasma hypo-osmolality, fluid intake must be strictly controlled and kept at the same level as or below diuresis.

Adolescent↗
PubMed1988

Absence of receptors for thyrotropin (TSH)-releasing hormone in human TSH-secreting pituitary adenomas associated with hyperthyroidism.

In patients with TSH-secreting pituitary adenomas associated with hyperthyroidism, TSH secretion usually does not respond to exogenous TRH stimulation. To determine the basis for this unresponsiveness, we studied TRH binding to the membranes of two such TSH-secreting pituitary adenomas. The patients, a 28-yr-old man and a 60-yr-old woman, had clinical and biochemical hyperthyroidism with increased serum TSH levels (15.7 and 14 mU/L, respectively; normal range, 1.1-7.2) and alpha-subunit to TSH molar ratios greater than 1 (2.4 and 1.7, respectively). Neither patients had an increase in serum TSH in response to TRH (200 micrograms, iv). Immunocytochemistry of the two adenomas, removed by transsphenoidal surgery showed a pure population of thyrotropic cells. Binding studies were performed by incubation of tumor cell membrane suspensions with increasing amounts of [3H]TRH. Two PRL-secreting adenomas and one normal human pituitary were used as controls. The characteristics of the TRH-binding sites from the control tissues were similar to those previously reported (Kd, 56, 30, and 49 nM; maximum binding, 187, 46, and 94 fmol/mg protein, respectively). In contrast, no specific TRH binding was found in the two TSH-secreting adenomas. We conclude that the unresponsiveness of TSH after TRH administration is related to the absence of specific TRH-binding sites in these thyrotropic tumors.

Adenoma↗
PubMed1988

Transsphenoidal pituitary surgery for the treatment of Cushing's disease: results in 64 patients and long term follow-up studies.

Transsphenoidal pituitary surgery was performed in 64 patients with Cushing's disease in search of a corticotroph adenoma. In 4 patients, profuse local bleeding prevented completion of the exploration. Of the 60 patients who had an adequate exploration, 4 could not be followed after surgery. Short term assessment of the surgical outcome (3-6 months postoperatively) was performed on 60 patients, including the 4 who had incomplete pituitary exploration. Forty-two patients (70%) were judged as immediate successes [urinary cortisol excretion, less than 90 micrograms (less than 248 nmol)/day]; the mean urinary cortisol excretion and plasma ACTH level fell from 463 +/- 70 (+/- SE) to 26.7 +/- 3.6 micrograms/day (1277 +/- 193 to 74 +/- 10 nmol/day; n = 33) and from 111 +/- 33 to 36 +/- 14 pg/mL (24 +/- 7 to 8 +/- 3 pmol/L; n = 23) in patients who had both measurements pre- and postoperatively. Eighteen patients (30%) were judged as immediate failures; neither urinary cortisol excretion nor plasma ACTH levels changed significantly in patients who had both measurements pre- and postoperatively. The preoperative epidemiological, clinical, hormonal, and radiological characteristics of the 2 groups were similar. Histological examination of pituitary fragments removed in 58 of the 60 patients evaluated postoperatively revealed the presence of tumoral tissue in a higher percentage of patients in the immediate success group (72%) than in the immediate failure group (24%; P less than 0.01). The 42 patients in the immediate success group were followed from 6 months to 7 yr (median, 2 yr); 6 patients had recurrences from 2-3 yr after operation. Actuarial analysis indicates that the probability of a patient remaining well 6 yr after surgery is 72 +/- 20% (95% confidence limit). Most of the patients in the immediate success group had transient ACTH deficiency preceding a progressive return to normal pituitary-adrenal function.

Adenoma↗
PubMed1988

[Stereotaxic guidance in open surgery of the brain].

The authors describe the technique used to precisely locate, before surgical ablation, small superficial or deep seated intracerebral lesions. When they are superficial, a burrhole is placed above the lesional site, that is reconstructed by superimposing the CT image onto a plain film radiogram taken during stereotaxy. Deep seated lesions are localized by inserting a guide under stereotaxy, prior to open surgery, which will lead the neurosurgeon without error from the cortex to the lesion. 37 observations are reported where this technique lead to a greatly simplified intervention with minimal cortical damage.

Brain↗
PubMed1986

[Middle-term course of craniopharyngiomas in children as a function of initial therapeutic choice].

Despite numerous studies and publications, the treatment of craniopharyngiomas in children remains controversial. The present series of 33 cases, followed for the last 10 years, is analysed according to therapeutic protocols jointly defined, case by case, from each patient's features and in restricting the extent of surgical excisions. In agreement with other recently published series, two options give superior results: complete excision, when the risk is low; in the other cases, partial excision or rather a simple biopsy or decompression, followed by irradiation. Risks of relapse are thus quite reduced and mortality greatly reduced. The unavoidable consequence of hypopituitarism is easily treated. However, the frequency of psychic and/or neurologic sequellae as well as the risk of post-radiation complications should not be disregarded when selecting treatment.

Adolescent↗
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↗
PubMed1979

[Anastomosis between subclavian artery and V. A. at C1-C2 level. Case report and reappraisal of surgical possibilities on the third portion of the vertebral artery (author's transl)].

A reappraisal of surgical possibilities on the third portion of the Vertebral Artery (V.A.) above C2, have been done from an anatomical study on 20 autopsied specimen. A route passing between the Internal Jugular Vein and the Sternocleido-mastoidian muscle allows a rather simple approach of the transverse process of C1. After dividing two muscles taking insertion on this process, 1,5 cm of the V.A. can be exposed. For larger exposure of the artery, the Foramen Transversaris of C1 must be unroofed and the artery dissected in the guttering of the posterior arch of Atlas. This surgical route was used in a case of aneurismal dysplasia at C3 level. An anastomosis between Subclavian Artery and V.A. at C1-C2 level was realized with an autologous saphenous vein graft. The keypoints are the highest possible freeing of the XI nerve and the head position. Rotation and extension move the transverse process and the posterior arch of Atlas superficially and anteriorly.

Humans↗
PubMed1979

[Double malformation discovered during investigations for hypertension; single pelvic kidney and occipitovertebral joint malformation (author's transl)].

A young Portuges eman with a spastic gait was found to have a kidney lying below the bladder. This was the only kidney present and its blood supply was derived from a renal artery which was also the only one present. This renal abnormality was associated with a major malformation of the occipitovertebral joint (occipitalization of the atlas, total occipito-atlanto-odontoid dissociation above the line of the digastric). The possible relationship between these two affections is discussed.

Abnormalities, Multiple↗
PubMed1978

Thalamic spatial variability and the surgical results of lesions placed with neurophysiologic control.

One hundred stereotactic thalamotomies performed for upper extremity tremor were reviewed and the spatial positions of the anterior limit of ventralis posterior (VP), the thalamic-internal capsular boundary and somatotopic areas within VP plotted with respect to the midline and the place of the anterior comissure. Considerable variability was noted as to the location of these points. The surgical results following 97 of the 100 thalamotomies were evaluated at least three months after the procedure. Fifty-six of 70 patients with Parkinsonian tremor had complete abolition of their upper extremity tremor, as did 20 out of 27 patients with intention tremon. Plotting the spatial positions of the lesions in those cases in which the tremor was abolished and those cases in which tremor continued revealed little difference. However, in all of the cases in which upper extremity tremor was totally abolished, the lesion site was situated in ventralis lateralis anterior to the VP representation of the buccal commissure, thumb, or index finger. This study not only demonstrates the wide range of individual spatial variability in thalamic structures, and the necessity for neurophysiologic corroboration of radiologic information during stereotactic surgery if optimal results are to be obtained, but also suggests a somatotopic organization within ventralis lateralis.

Adolescent↗
PubMed1977

Connections of latero-dorsal nucleus of the thalamus. II. Experimental study in Papio papio.

Modifications of the latero-dorsal (L.D.) nucleus of the thalamus have been observed earlier in man in relation to limbic lesion of various etiologies. Our proposal was to determine the role of L.D. in memory disturbances. We attempted to study the connections of L.D. in Papio papio baboon after surgical lesion using silver impregnations as well as traditional techniques. We found three afferent pathways: from the fornix, the posterior cingulate and the parietal cortex (area 7). The most important is the afferent system from the fornix, it terminates in the antero-dorso-medial part of L.D.; the other two afferent pathways have a postero-lateral projection in L.D. The three efferent systems to parietal cortex, cingulate and fornix were not delineated in this study. It was concluded that the antero-dorso-medial portion of L.D. is connected to the limbic system and the ventro-postero-lateral portion integrated into a large parieto-cingulo-parahippocampal circuit to which it is joined by direct and indirect projections with several relays. These connections have important implications, perhaps, in our understanding of memory disturbances.

Afferent Pathways↗