Endocrinopathies and renal outcomes in lithium therapy: impact of lithium toxicity

BACKGROUND

Lithium is the mainstay of treatment for bipolar disorder, mania and an augmentation therapy in patients with treatment resistant depression. It has a narrow therapeutic index, with recognized adverse multi-system and endocrine side effects.

AIM

To assess the impact of lithium therapy, in particular lithium toxicity, on the development of endocrine and renal disorders in a cohort of patients in a single tertiary referral centre in Ireland.

STUDY DESIGN

A retrospective analysis was performed of the prevalence of lithium toxicity and renal, thyroid and parathyroid dysfunction in our study population.

METHODS

We collected laboratory data from the Clinical Chemistry department of the Adelaide and Meath Hospital incorporating the National Children's Hospital (AMNCH), Dublin, Ireland. Our study population included all patients who had at least one serum lithium measurement from January 1st 2000 to December 31st 2014 inclusive.

RESULTS

A total of 580 patients were included in the study. Among our study group, 70 patients (12.1%) had 1 toxic lithium measurement (lithium level >1.2 mmol/l). 27.8% (n > 161) of patients developed stage 3 Chronic kidney Disease (CKD) or higher, which was commoner in those patients who developed toxic lithium levels (P < 0.0001) and in those who developed hypernatraemia (P > 0.0001). 16.2% of patients (n > 94) had one serum sodium >145 mmol/l during follow up. 60 patients(10.3%) had a TSH >10 mU/l, while complete suppression of TSH (<0.05 mU/l) was observed in 22 patients (3.8%) during follow-up. 4% (n > 37) of the study population had ≥1 serum corrected calcium level > 2.55 mmol/l, and 4 patients had biochemical confirmation of primary hyperparathyroidism but PTH levels were only performed in 2.8% (n > 16) of the studypopulation.

CONCLUSION

Stage 3 CKD is common in patients receiving lithium therapy. Lithium toxicity is associated with CKD and hypernatraemia. Thyroid dysfunction and hypercalcaemia are common in patients receiving lithium therapy. Patients receiving lithium therapy require surveillance of renal, thyroid and bone biochemistry.

Acromegaly

Acromegaly is a rare, chronic, progressive disease characterized by an excess secretion of growth hormone (GH) and increased circulating insulin-like growth factor 1 (IGF-1) concentrations. It is caused by a pituitary adenoma in the vast majority of cases. The clinical diagnosis, based on symptoms related to GH excess, is often delayed due to the insidious nature of the disease. Consequently, patients often have established systemic complications at diagnosis with increased morbidity and premature mortality. Serum IGF-1 measurement is recommended as the initial screen for patients with suspected acromegaly. The gold standard diagnostic test remains the oral glucose tolerance test with concomitant GH measurement. Therapy for acromegaly is targeted at decreasing GH and IGF-1 levels, ameliorating patients' symptoms and decreasing any local compressive effects of the pituitary adenoma. The therapeutic options for acromegaly include surgery, medical therapies (such as dopamine agonists, somatostatin receptor agonists and the GH receptor antagonist pegvisomant) and radiotherapy. A multidisciplinary approach is recommended with often a requirement for combined treatment modalities. With disease control, associated morbidity and mortality can be reduced. The recently published evidence-based guidelines by the Endocrine society addressed important clinical issues regarding the evaluation and management of acromegaly. This review discusses advances in our understanding of the pathophysiology of acromegaly, diagnosis of various forms of the disease and focuses on current treatment modalities, and on future pharmacological therapies for patients with acromegaly.

Heterogenous patterns of recovery of thirst in adult patients with adipsic diabetes insipidus

BACKGROUND

The natural history of adipsic diabetes insipidus (ADI) is not well described, and reports of recovery of thirst are rare.

DESIGN AND METHODS

Case histories presentation. ADI was identified by demonstrating absent thirst and arginine vasopressin (AVP) responses to hypertonic saline infusion.

RESULTS

Twelve patients with ADI were identified (craniopharyngioma 5, anterior communicating artery aneurysm (ACOM) repair 4, congenital 1, neurosarcoidosis 1, prolactinoma 1). Three patients died. Six patients had permanent ADI. Three patients had recovery of thirst, with a heterogenous pattern of recovery. In the first case, ADI had developed after clipping of an ACOM aneurysm. Ten years after surgery; he sensed the return of thirst; repeated hypertonic saline infusion showed recovery of thirst and AVP secretion. In the second case, a 41-year-old female with an intrasellar craniopharyngioma developed post-operative ADI with persistent hypernatremia. Two years post-operatively, she complained of thirst, and hypertonic saline infusion showed normalization of thirst but absent AVP responses, confirming recovery of thirst, but with persistent diabetes insipidus (DI). In the third case, a 29-year-old Caucasian had craniotomy and radiotherapy for craniopharyngioma and developed ADI post-operatively. Eight years post-op, she presented with thirst, seizures and pNa of 112 mmol/l. Hypertonic saline infusion showed persistent DI but thirst responses typical of compulsive water drinking; she has had recurrent hyponatraemia since then.

CONCLUSIONS

We report that 3/12 patients with ADI recovered thirst after longstanding adipsia with heterogenous pattern of recovery. Both the mortality of 25% and the recovery rate of 25% should be considered when planning long-term surveillance.

The thoracic anterior spinal cord adhesion syndrome

OBJECTIVES

This study included a series of middle-aged male and female patients who presented with chronic anterior hemicord dysfunction progressing to paraplegia. Imaging of anterior thoracic cord displacement by either a dural adhesion or a dural defect with associated cord herniation is presented.

METHODS

This is a retrospective review of cases referred to a tertiary neuroscience centre over a 19-year period. Imaging series were classified by two experienced neuroradiologists against several criteria and correlated with clinical examination and/or findings at surgery.

RESULTS

16 cases were available for full review. Nine were considered to represent adhesions (four confirmed surgically) and four to represent true herniation (three confirmed surgically). In the three remaining cases the diagnosis was radiologically uncertain.

CONCLUSION

The authors propose "thoracic anterior spinal cord adhesion syndrome" as a novel term to describe this patient cohort and suggest appropriate clinicoradiological features for diagnosis. Several possible aetiologies are also suggested, with disc rupture and inflammation followed by disc resorption and dural pocket formation being a possible mechanism predisposing to herniation at the extreme end of a clinicopathological spectrum.

Is there a causal relationship between the hypoxia-ischaemia associated with cardiorespiratory arrest and subdural haematomas? An observational study

The aim of this study was to determine the frequency of subdural haematomas (SDHs) occurring in infants presenting following atraumatic cardiorespiratory collapse. This study was a review of retrospective case notes, brain imaging and post-mortem examinations carried out in the paediatric intensive care unit (PICU) and emergency department (ED) in a tertiary paediatric centre in the UK. The study included infants and children less than 4 years old dying in the ED or admitted to the PICU after atraumatic cardiorespiratory arrest. We identified macroscopic SDHs on brain imaging or post-mortem examination. Of those children who experienced a cardiorespiratory arrest from a non-traumatic cause and met inclusion criteria, 33 presented and died in the ED and 17 were admitted to the PICU. These children had a post-mortem examination, brain imaging or both. None of these infants had a significant SDH. One child had a small clot adherent to the dura found on post-mortem and two had microscopic intradural haemorrhage, but it is unclear in each case whether this was artefact, as each had otherwise normal brains. Subdural haematoma arising in infants or young children in the context of catastrophic cardiorespiratory compromise from a non-traumatic cause was not observed.

Imaging of acute neurological conditions in pregnancy and the puerperium

Eclampsia is one of the most common acute neurological events occurring during pregnancy. However, there are many other conditions that can present during pregnancy and the puerperium and that may either mimic eclampsia or produce other acute neurological manifestations. Frequently the symptoms and signs are non-specific, and it can be difficult to differentiate between these conditions on clinical grounds alone. Neuroradiological studies can provide valuable diagnostic information, and interventional radiological procedures may play a part in the subsequent management of these conditions. This review focuses on the imaging of acute neurological conditions which may be associated with, or present during, pregnancy and the puerperium.

The influence of training on tinnitus perception: an evaluation 12 months after tinnitus management training

Sixty-five subjects were reviewed 12 months after tinnitus management training, which had been comprised variously of information, relaxation training and a therapeutic noise strategy. Seventy-four per cent of subjects reported increased habituation to tinnitus (n = 48), 65% reported reduced tinnitus annoyance (n = 42), and 52% reported an increased ability to cope with tinnitus (n = 34). Twenty-five per cent of subjects reported deterioration in coping ability (n = 16), 23% reported reduced habituation to tinnitus (n = 15) and 8% reported increased tinnitus-related annoyance (n = 5). None of the management strategies were found to be significantly more effective than others in facilitating improved coping or habituation to tinnitus. Subjects who reported reduced coping and habituation to tinnitus experienced greater levels of general life stress than subjects who reported increased habituation and coping ability. The use of relaxation therapies as applied in this study did not appear to influence the level of tinnitus distress or the level of life stress. Thirty-seven per cent of subjects given long-term low-level white noise (LTWN) stimulation reported benefit. However, LTWN stimulation did not significantly alter tinnitus awareness or the minimum masking level (MML) of tinnitus. Long-term low-level white noise stimulation appeared to influence cognitive reaction to tinnitus rather than its physical perception. Subjects who initially had low ability to cope with tinnitus and preferred a more active coping style reported significantly greater benefit from LTWN stimulation than subjects whose primary approach to coping was to regulate the emotional impact of tinnitus.

Managing tinnitus: a comparison of different approaches to tinnitus management training

A series of studies examining the interaction between the characteristics of individual tinnitus sufferers and the effectiveness of the methods used to assist them has been conducted. The first of these studies provided a baseline description of 96 people with tinnitus, according to a range of audiological and psychological variables. In the present paper four differing tinnitus management programmes are described and the related changes in tinnitus perception reported three months after tinnitus management training. For the majority of subjects, the tinnitus was less annoying and less distressing three months after attending tinnitus management training. However, the majority of subjects reported no change in tinnitus loudness, or tinnitus awareness and no change in their tinnitus coping ability. Subjects receiving low level white noise stimulation reported greater improvement in tinnitus coping ability than subjects who received information and relaxation training, although there was no associated improvement in tinnitus awareness. Subjects' beliefs about tinnitus and preferred coping style may have influenced the reported benefit or otherwise of the differing tinnitus management techniques.

Audiological and psychological characteristics of a group of tinnitus sufferers, prior to tinnitus management training

A profile of audiological and psychological characteristics, obtained before starting tinnitus management training, is presented for 96 subjects with tinnitus. Variability was marked in all measures. A history of headaches, neck or back pain, or balance problems was not related to the ability to cope with tinnitus. The coping strategies used to manage tinnitus were influenced by the beliefs held about tinnitus, but the coping strategies chosen were not necessarily effective. No gender differences were found in coping ability or overall stress levels, although there were gender differences on some psychological measures and stress influences. Subjects who had previously sought assistance differed from those who had not in the complexity of the tinnitus sounds, the level of emotional reaction and the use of coping behaviours.

Drugs, alcohol and road accidents in Tasmania

Drug analyses were performed on 200 blood samples that were taken for alcohol analysis from road users in Tasmania. Alcohol at a concentration of above 0.5 g was found in 75% of the samples, and other drugs were found in 17% of the samples. Cannabis was the most prevalent of these other drugs: it was detected in 6% of road users; benzodiazepine drugs were detected in 5% of road users; and barbiturate drugs were detected in 2% of road users. Alcohol was found in 50% and other drugs were found in 25%, of drivers, riders and pedestrians who were involved in road accidents that were serious enough to cause death or injury. In addition to alcohol, other drugs may be making a significant contribution to road accidents because all the drugs that were identified are capable of impairing psychomotor performance. Of particular concern is the prevalence of cannabis, which is an illegal drug, and barbiturate drugs, which are now prescribed rarely. A well-controlled study is required to quantitate the contribution of drugs other than alcohol to road accidents. In the meantime, drivers should be warned that drugs that depress the central nervous system can be expected to impair driving ability and to increase the risk of an accident.