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Hypophysitis is defined as inflammation of the pituitary gland. It is a heterogeneous condition as it can originate from different parts of the pituitary gland, can be caused by different pathophysiological processes, and can be isolated or the manifestation of a underlying systemic disease. Hypophysitis usually presents with endocrine deficiencies, including diabetes insipidus, with varying patterns. A subset of patients presents with mass effects. The last decades major progress has been made in the understanding of this disease. New forms are now recognized, new diagnostics are being developed, and specific treatments are proposed. This review provides an overview of the current knowledge on hypophysitis using an aetiology-based approach and provides the clinician with a stepwise approach to the patient with (suspected) hypophysitis., (Copyright © 2021. Published by Elsevier Masson SAS.)

Primary brain tumours are relatively rare, but brain metastases are a frequent complication of the most common cancers elsewhere in the body (breast, lung, melanoma). Loss of function and excitation of brain nerves i.e. sensory loss, paralysis and pain in the head-and-neck region are specific features in base of skull tumours: meningioma, glomus tumours, vestibular Schwannoma, meningeal metastases by breast cancer, melanoma, and leukaemia, melanoma. In the diagnosis and treatment of brain tumours, special attention is required for rare complications in the head and neck region.

Three patients, aged 2, 2.5 and 24 years, presented with a skin lesion in the median or paramedian area at the nose, in the lumbar region and between the shoulders, respectively. The first patient suffered from recurrent infection, the skin lesion of the second patient was a coincidental finding, and the third patient had cosmetic problems. Although there were no signs of neurological deficits, neurodermal closing defects were found by MRI. Two patients underwent surgery to prevent infection and neurological complaints in the future. It is stressed that even if there are no neurological signs or infections, congenital dermal lesions situated in the midline should be considered as possible neural tube defects and therefore analysed by MRI. Ifa neurodermal dysraphism is found, patients should be referred to a neurosurgical centre. A good clinical assessment of the neural lesion, clinical signs and age will determine whether surgical resection is indicated to prevent or resolve neurological problems, infections or cosmetic complaints.

The discovery of endogenous opioids has markedly influenced the research on the biology of addiction and reward brain processes. Evidence has been presented that these brain substances modulate brain stimulation reward, self-administration of different drugs of abuse, sexual behaviour and social behaviour. There appears to be two different domains in which endogenous opioids, present in separate and distinct brain regions, are involved. One is related to the modulation of incentive motivational processes and the other to the performance of certain behaviours. It is concluded that endogenous opioids may play a role in the vulnerability to certain diseases, such as addiction and autism, but also when the disease is present, such as alcoholism.

Level-changing behavior is a form of anticipatory behavior of a male rat, when tested in a bilevel testbox. The male explores the testcage prior to introduction of a female. The female is introduced after 5 min. The number of level changes displayed by the male in this period reflects appetitive aspects of sexual behavior and it was suggested that analysis of this level-changing behavior may function as assessment of sexual motivation. In this study the increase of anticipatory level changes over repeated weekly tests was dependent upon (sexual) olfactory stimulation. The number of anticipatory level changes was reliably reduced by administration of the opioid antagonist naloxone, suggesting that endogenous opioids facilitate this behavior. These results suggest that the increase of anticipatory level changes over repeated tests is a response to olfactory stimuli and reflects appetitive aspects of sexual behavior, which are stimulated by endogenous opioids. These results are in accordance with the concept that analysis of anticipatory level-changing behavior can be used to assess sexual motivation.

Anticipatory level-changing behavior is a form of appetitive sexual behavior displayed by male rats prior to introduction of a female in a bilevel testbox. Analysis of this level-changing behavior may serve as assessment of sexual motivation. Because ejaculation affects appetitive aspects of sexual behavior, measures purporting to assess sexual motivation should be effected by ejaculation. We observed that ejaculation prior to testing reduced the number of anticipatory level changes of a male rat. This reduction was greater when tested after two than after one ejaculation. Our results support the concept that analysis of anticipatory level-changing behavior can be used to measure sexual motivation.

The sexual motivation and performance of male rats were observed in a bilevel testing chamber after bilateral infusion of 40 pmol beta-endorphin, 2.75 nmol naloxone or saline into the ventral tegmental area for four succeeding, weekly tests. In the 5 min prior to introduction of the female rat, the male rat explores the bilevel testing chamber. It was previously shown that the increase over tests of these anticipatory level changes is sexually motivated and a response to olfactory stimuli. Naloxone infusion into the VTA prevented the increase of anticipatory level changes. beta-Endorphin failed to affect the anticipatory level-changing behavior. The sexual performance was unaffected by naloxone or beta-endorphin treatment, but the number of ejaculating rats decreased with repeated testing after naloxone treatment. It is concluded that endogenous opioid systems in the ventral tegmental area contribute to the stimulation of sexual motivation and/or reward, presumably by stimulating the mesolimbic dopamine system in response to sex-related olfactory stimuli.

In recent years much has become known about the substrates in the brain involved in the regulation of masculine sexual behavior and the involvement of specific neurochemicals in these brain areas. In the present paper the experimental data concerning the involvement of a number of brain areas in sexual behavior are reviewed, in relation to an incentive motivational theory of sexual behavior. The review is restricted to the involvement of opioids and dopamine, of which the role in sexual motivation and behavior is best documented. Opioids in the medial preoptic area (mPOA) impair sexual performance, although the endogenous opioids systems may be quiescent in normal, sexually active rats. Dopamine in the mPOA has a facilitative role in the masculine sexual performance. The corticomedial amygdala is involved in processing of sensory information, especially olfactory stimuli, which are subsequently directed towards the mPOA. Local beta-endorphin infusion interferes with this processing. Endogenous opioids in the ventral tegmental area activate the mesoaccumbens dopamine system and stimulate the sexual motivation. Increased dopamine transmission in the nucleus accumbens correlates with increased sexual motivation and vice versa. The basolateral amygdala plays an essential role in the association of environmental stimuli with reward and therefore in the expression of conditioned sexual motivation. Finally, the reviewed data are integrated and a comprehensive view on the relations between various neural substrates is composed.

Local infusion of beta-endorphin (beta-END) into the medial preoptic area (MPOA) dose-dependently impaired the gating of the copulatory response and the execution of the sexual performance of sexually experienced, intact male rats. Local naloxone treatment prevented the impairment of the sexual response by beta-END, but failed to facilitate unimpaired copulation. Local infusion into the MPOA of equimolar doses of alpha-endorphin, dynorphin-A-(1-17) or met-enkephalin were less effective than beta-END. It is suggested that endogenous opioid systems in the MPOA are normally quiescent, and increased activity may be related to disrupted or inhibited male sexual behavior.

The sexual motivation and performance of sexually experienced male rats were tested during the light phase of the diurnal cycle after treatment with saline or 1 mg.kg-1 naloxone in a bilevel testing box. The sexual motivation during the light phase, as assessed by the increase in anticipatory level changes prior to introduction of a receptive female on subsequent weekly sessions, was comparable to that during the dark phase. Opioid blockade reduced the increase of level changes, suggesting that endogenous opioids are involved in sexual motivation. The sexual performance was impaired during the light phase. Naloxone treatment failed to affect the sexual performance, other than that the post ejaculatory refractory period was increased. This increased latency to re-initiate copulation may be an expression of the reduced sexual motivation. It is concluded that endogenous opioids are not involved in the regulation of the impaired sexual performance during the light phase of the diurnal cycle. In contrast, the sexual motivation, which displays no marked diurnal variation, may be stimulated by endogenous opioids.

gamma-Type endorphins mimic neuroleptics in inducing a grasping response in rats. It was studied whether the haloperidol-induced grasping response was altered after blockade of gamma-type endorphin activity in the rat brain. To achieve this blockade rats were injected i.c.v. with gamma-endorphin antiserum or with a monoclonal anti-idiotype desenkephalin-gamma-endorphin antibody, which may bio-inactivate the gamma-type endorphins or block the putative receptors for gamma-type endorphins, respectively. The results showed that both treatments attenuated the haloperidol-induced grasping response, particularly 3 h after haloperidol treatment. The influence of these antibodies appeared to be specific, since other sera were without effect. Thus there may be an interaction between the endogenous gamma-type endorphin activity and the haloperidol-induced grasping response.