The fixation suppression test can uncover vertical nystagmus of central origin in some patients with dizziness

Des mesurages répétés de la fixation thyroïdienne de 10 minutes du 132I injecté intraveineusement on été effectués sur 55 malades euthyroïdiens sans et avec goitre et sur 16 malades hyperthyreoïdiens par 4 jours consécutifs. Immédiatement après le premier mesurage tous les malades recevaient une dose unique oral de 100 μg de Triiodothyronine (T3). Les valeurs de fixation 24, 48 et 72 heures après le T3 (moyen ± déviation standard) étaient de 75 ± 1,7, 64 ± 1,8, et 67 ± 1,9 dans le groupe euthyroïdien et le 106 ± 2,6, 104 ± 2,2 et 108 ± 4,0 dans le groupe hyperthyroïdien, exprimés en pourcentage du groupe controle. 48 heures après T3 tous les personnes euthyroïdiens, sauf une, avaient des valeurs en dessous de 88% tandis que la valeur la plus basse des personnes hyperthyroïdiens ce jour était de 93%. La séparation des valeurs 48 heures des deux groupes était complète après avoir respecté l’influence de la première fixation sur la valeur 48 heures. On peut donc supposer q’un test thyroïdien de suppression utilisable en clinique peut-être effectué en 48 heures après une administration oral de 100 μg de T3 et mesurage de la fixation 10 minutes après l’injection du radioisotope.

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A Comparison of Serum Thyroxine [T4(D)], RT3U Ratio and T4-RT3 Index with Radioiodine Uptake in the Triiodothyronine Suppression Test

Nuklearmedizin ◽

10.1055/s-0038-1624794 ◽

1972 ◽

Vol 11 (04) ◽

pp. 317-323

Author(s):

R. Höschl ◽

T. M. D. Gimlette

Keyword(s):

Free Thyroxine ◽

Radioiodine Uptake ◽

Serum Thyroxine ◽

Before And After ◽

Free Thyroxine Index ◽

Suppression Test

SummaryA total of 132 triiodothyronine suppression tests were performed using 100 μg of T3 for 7 days. Radioiodine uptake at four hours, serum thyroxine [T4(D)], T3 binding coefficient [RT3U ratio] and free thyroxine index [T4-RT3 index] were estimated before and after a course of triiodothyronine.T4(D) decreased significantly in only 38.4% of T3 suppression tests assessed as positive by the decrease in radioiodine uptake; it did not change or increased significantly in 84.7% of tests negative by radioiodine uptake.RT3U ratio showed little change in all groups. The changes in T4-RT3 index were similar to those of T4(D).The correlation of changes in T4(D) with 4 hour radioiodine uptake is poor (r = 0.34).Agreement between changes in radioiodine uptake and T4(D) was observed only in 54% of tests; between changes in uptake and T4-RT3 index in 69.4%.Estimation of serum thyroxine or free thyroxine index in the T3 suppression test cannot substitute for the radioiodine uptake for reasons which are discussed.

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SIMPLIFIED DEXAMETHASONE SUPPRESSION TEST

Acta Endocrinologica ◽

10.1530/acta.0.0610219 ◽

1969 ◽

Vol 61 (2) ◽

pp. 219-231 ◽

Cited By ~ 14

Author(s):

V. H. Asfeldt

Keyword(s):

Cushing’S Syndrome ◽

Normal Subjects ◽

Cushing's Syndrome ◽

Dexamethasone Suppression Test ◽

Clinical Value ◽

Suppression Test ◽

The One ◽

Steroid Excretion ◽

Dexamethasone Suppression

ABSTRACT This is an investigation of the practical clinical value of the one mg dexamethasone suppression test of Nugent et al. (1963). The results, evaluated from the decrease in fluorimetrically determined plasma corticosteroids in normal subjects, as well as in cases of exogenous obesity, hirsutism and in Cushing's syndrome, confirm the findings reported in previous studies. Plasma corticosteroid reduction after one mg of dexamethasone in cases of stable diabetes was not significantly different from that observed in control subjects, but in one third of the insulin-treated diabetics only a partial response was observed, indicating a slight hypercorticism in these patients. An insufficient decrease in plasma corticosteroids was observed in certain other conditions (anorexia nervosa, pituitary adenoma, patients receiving contraceptive or anticonvulsive treatment) with no hypercorticism. The physiological significance of these findings is discussed. It is concluded that the test, together with a determination of the basal urinary 17-ketogenic steroid excretion, is suitable as the first diagnostic test in patients in whom Cushing's syndrome is suspected. In cases of insufficient suppression of plasma corticosteroids, further studies, including the suppression test of Liddle (1960), must be carried out.

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DETERMINATION OF BLOOD CORTICOIDS USING THE IN VITRO RESIN UPTAKE OF 3H-PREDNISOLONE

Acta Endocrinologica ◽

10.1530/acta.0.0570023 ◽

1968 ◽

Vol 57 (1) ◽

pp. 23-32 ◽

Cited By ~ 2

Author(s):

Hironori Nakajima ◽

Mitsunori Murala ◽

Masumitsu Nakata ◽

Takeshi Naruse ◽

Seiji Kubo

Keyword(s):

Thyroid Function Test ◽

Normal Subjects ◽

Adrenal Function ◽

Function Test ◽

Before And After ◽

Adrenal Response ◽

Suppression Test

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.

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Pituitary apoplexy in Cushing's disease after a standard low-dose dexamethasone suppression test

Endocrine Abstracts ◽

10.1530/endoabs.37.ep1241 ◽

2015 ◽

Author(s):

Mouna Mezoued ◽

Djamila Meskine ◽

Amine Habouchi

Keyword(s):

Cushing’S Disease ◽

Low Dose ◽

Pituitary Apoplexy ◽

Dexamethasone Suppression Test ◽

Cushing's Disease ◽

Suppression Test ◽

Dexamethasone Suppression

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The Invisible Evil Twin of an Adrenal Adenoma

Journal of Clinical and Health Sciences ◽

10.24191/jchs.v4i1.7283 ◽

2019 ◽

Vol 4 (1) ◽

pp. 58

Author(s):

Aimi Fadilah Mohamad ◽

Fatimah Zaherah Mohamed Shah ◽

Nur Aisyah Zainordin ◽

Ur 'Aini Eddy Warman ◽

Nazimah Ab Mumin ◽

...

Keyword(s):

Adrenal Glands ◽

Adrenal Adenoma ◽

Definitive Diagnosis ◽

Dynamic Tests ◽

Venous Sampling ◽

Aldosterone Secretion ◽

Aldosterone Level ◽

Suppression Test ◽

The Right ◽

Secondary Causes

Primary aldosteronism (PA) causes a persistently elevated blood pressure (BP) due to excessive release of the hormone aldosterone from the adrenal glands. Classically, it is called Conn’s syndrome and is described as the triad of hypertension and hypokalemia with the presence of unilateral adrenal adenoma. It can be cured with surgical resection of the aldosterone-secreting adenoma leading to resolution of hypertension, hypokalemia and increased cardiovascular risk associated with hyperaldosteronism. We present a case of a man with previous ischemic heart disease (IHD) who presented with resistant hypertension. Investigations for secondary causes of hypertension revealed an elevated aldosterone level and saline suppression test confirmed the diagnosis of PA. Radiological examination revealed a left adrenal adenoma and a normal right adrenal gland. However, adrenal venous sampling showed lateralization of aldosterone secretion towards the right. He subsequently underwent a laparoscopic right adrenalectomy which improved his BP control promptly. This case highlights the importance of recognizing the need to investigate for secondary causes of hypertension. It also underscores the importance of dynamic tests, which may not be easily accessible to most clinicians but should pursue, to allow a definitive diagnosis and effective treatment.

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Upbeat vertical nystagmus after brain stem cavernoma resection: a rare case of nucleus intercalatus/nucleus of roller injury

Journal of Neurology ◽

10.1007/s00415-020-09891-4 ◽

2020 ◽

Vol 267 (10) ◽

pp. 2865-2870

Author(s):

Torstein R. Meling ◽

Aria Nouri ◽

Adrien May ◽

Nils Guinand ◽

Maria Isabel Vargas ◽

...

Keyword(s):

Rare Case ◽

Vascular Malformations ◽

Clinical Manifestations ◽

Neurological Injury ◽

Medial Longitudinal Fasciculus ◽

Blurred Vision ◽

Complete Excision ◽

First Case ◽

Vertical Nystagmus ◽

Upbeat Nystagmus

Abstract Introduction CNS cavernomas are a type of raspberry-shaped vascular malformations that are typically asymptomatic, but can result in haemorrhage, neurological injury, and seizures. Here, we present a rare case of a brainstem cavernoma that was surgically resected whereafter an upbeat nystagmus presented postoperatively. Case report A 42-year old man presented with sudden-onset nausea, vomiting, vertigo, blurred vision, marked imbalance and difficulty swallowing. Neurological evaluation showed bilateral ataxia, generalized hyperreflexia with left-sided predominance, predominantly horizontal gaze evoked nystagmus on right and left gaze, slight left labial asymmetry, uvula deviation to the right, and tongue deviation to the left. MRI demonstrated a 13-mm cavernoma with haemorrhage and oedema in the medulla oblongata. Surgery was performed via a minimal-invasive, midline approach. Complete excision was confirmed on postoperative MRI. The patient recovered well and became almost neurologically intact. However, he complained of mainly vertical oscillopsia. The videonystagmography revealed a new-onset spontaneous upbeat nystagmus in all gaze directions, not suppressed by fixation. An injury of the rarely described intercalatus nucleus/nucleus of Roller is thought to be the cause. Conclusion Upbeat nystagmus can be related to several lesions of the brainstem, including the medial longitudinal fasciculus, the pons, and the dorsal medulla. To our knowledge, this is the first case of an iatrogenic lesion of the nucleus intercalatus/nucleus of Roller resulting in an upbeat vertical nystagmus. For neurologists, it is important to be aware of the function of this nucleus for assessment of clinical manifestations due to lesions within this region.

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