Acute and chronic effects of hypercalcaemia on cortical excitability as studied by 5 Hz repetitive transcranial magnetic stimulation

Actigraphy measures show sleep improvement after parathyroidectomy for primary hyperparathyroidism

IMPORTANCE

The symptoms of primary hyperparathyroidism are often subtle, such as fatigue, mood changes, and sleep disturbances. After parathyroidectomy, patients often report improvement in sleep and mood; however, objective data supporting these improvements is lacking.

OBJECTIVE

This prospective study uses standard measures to objectively and subjectively assess sleep in patients with primary hyperparathyroidism before and after parathyroidectomy.

DESIGN

A longitudinal prospective study was conducted over three one-week-long periods: pre-parathyroidectomy, 1-week post-parathyroidectomy, and three months post-parathyroidectomy. During each time point, patients wore an actigraphy device, recorded a sleep diary, and completed the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Depression Anxiety Stress Scale (DASS). Statistical analysis was performed using repeated measures models to compare the average measures among the three time points and test for trends over time.

SETTING

Single institution, tertiary care center.

PARTICIPANTS

Patients with primary hyperparathyroidism from ages 18 to 89 years old.

EXPOSURE

Parathyroidectomy between September 2020 and January 2024.

MAIN OUTCOMES AND MEASURES

Actigraphy data, consensus sleep diary, Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Depression Anxiety Stress Scales - 21 Items (DASS).

RESULTS

Thirty-six patients were enrolled, and 34 patients completed the study. Actigraphy data showed a significant negative trend in average sleep latency (p = 0.045) and average time in bed (p = 0.046). Sleep diary data showed additional differences in the number of awakenings (p = 0.002), wake after sleep onset (p < 0.001), sleep quality (p < 0.001), and sleep efficiency (p = 0.02) among the three time points and/or as a significant negative trend. PSQI and ISI scores were significantly different among the three time points (p = 0.002 and p < 0.001, respectively) and also declined significantly over time (p = 0.008 and p = 0.007, respectively). DASS depression, anxiety, and stress scores were significantly different among the three time points (p < 0.001, p = 0.01, and p < 0.001, respectively), and stress also declined significantly over time (p = 0.005).

CONCLUSION AND RELEVANCE

This study represents the most extensive prospective study demonstrating objective and subjective sleep and mood improvement in patients with primary hyperparathyroidism after parathyroidectomy.

Impairment in muscle strength and its determinants in primary hyperparathyroidism: A study in postmenopausal women

Neuromuscular impairment is described among the non-classical complications of primary hyperparathyroidism (PHPT). However, the extent of this complications and related mechanisms have not been fully addressed. The study aimed at assessing muscle strength and its main determinants in postmenopausal women with PHPT. We studied 48 postmenopausal women with PHPT (mean age 60.8 ± 5.6 SD years; BMI 25.6 ± 5.5 kg/m²) and 38 healthy postmenopausal women (mean age 58.6 ± 5.9; BMI 25.2 ± 3.5). In all subjects, the maximum voluntary contraction (MVC, Newton, N) was measured by Hand held Dynamometer (Kayser Italia srl, Livorno, Italy) and the lumbar spine, total hip, femoral neck, and non dominant distal one-third radius areal BMD (aBMD) by dual X-ray absorptiometry (DXA) (Hologic, Waltham, MA). Serum ionized calcium (Ca⁺⁺), parathyroid hormone (PTH), phosphorus (P), and 25-hydroxyvitaminD [25(OH)D] levels were measured in both groups. A subgroup of 30 PHPT women agreed to participate to the follow-up sub-study and were re-assessed 24 months after parathyroidectomy (n = 15) or after baseline evaluation (n = 15). Patients with PHPT had significant lower MVC values compared to healthy women (p < 0.001). As expected, serum Ca⁺⁺ and PTH levels were higher and P lower in PHPT compared to controls. We observed a significant association between MVC and total hip and one-third radius aBMD (R = 0.320 and 0.370, p < 0.05) and negative association with Ca⁺⁺ (R = -0.340, p < 0.05) in the PHPT group; MVC was positively associated with one-third radius aBMD (R = 0.360, p < 0.05) and negatively with age, BMI and myostatin (R = -0.390, -0.340 and -0.450, p < 0.05) in the group of healthy women. The linear model using BMI, Ca⁺⁺, P, 25(OH)D, PTH, myostatin, and aBMD as covariates showed that one-third radius aBMD was positively associated with MVC in PHPT patients (p < 0.02) and in healthy subjects (p < 0.001). Additionally, serum PTH and myostatin were negatively associated with MVC in healthy subjects (p < 0.03 and p < 0.01). The linear model showed that surgery was associated with an increase in MVC (p < 0.05) in PHPT patients after 24 months, all other variables being equal and by controlling for baseline values of MVC. Handgrip strength is significantly impaired in postmenopausal women with PHPT. Some common mechanisms influencing muscle function exist in PHPT and in healthy subjects; they are associated with the reduced aBMD at cortical sites. Hypercalcemia seems to be one of the main determinants of impairment in muscle strength in PHPT, while no role is played by myostatin.

Comparison of toxicity and cellular responses following pulmonary exposure to different types of nanofibers

Pulmonary effects of inhaled microfibers are an emerging public health concern. In this study, we investigated toxicity following pulmonary exposure to synthetic polyethylene oxide fibroin (PEONF) and silk fibroin (SFNF) nanofibers and the cellular responses. When instilled intratracheally weekly for four weeks, body weight gain was significantly reduced in female mice exposed to the higher dose of SFNF when compared with the control group. The total number of cells in the lungs was more significant in all treated groups than in the control, whereas the relative portion of neutrophils and eosinophils increased significantly only in female mice exposed to SFNF. Both types of nanofibers induced notable pathological changes and increased pulmonary expression of MCP-1α, CXCL1, and TGF-β. More importantly, blood calcium, creatinine kinase, sodium, and chloride concentration were affected significantly, showing sex- and material-dependent differences. The relative portion of eosinophils increased only in SFNF-treated mice. In addition, both types of nanofibers induced necrotic and late apoptotic cell death in alveolar macrophages after 24 h of exposure, with accompanying oxidative stress, increased NO production, cell membrane rupture, intracellular organelle damage, and intracellular calcium accumulation. Additionally, multinucleated giant cells were formed in cells exposed to PEONF or SFNF. Taken together, the findings indicate that inhaled PEONF and SFNF may cause systemic adverse health effects with lung tissue damage, showing differences by sex- and material. Furthermore, PEONF- and SFNF-induced inflammatory response may be partly due to the low clearance of dead (or damaged) pulmonary cells and the excellent durability of PEONF and SFNF.

Brain dysfunction in tubular and tubulointerstitial kidney diseases

Kidney function has two important elements: glomerular filtration and tubular function (secretion and reabsorption). A persistent decrease in glomerular filtration rate (GFR), with or without proteinuria, is diagnostic of chronic kidney disease (CKD). While glomerular injury or disease is a major cause of CKD and usually associated with proteinuria, predominant tubular injury, with or without tubulointerstitial disease, is typically non-proteinuric. CKD has been linked with cognitive impairment, but it is unclear how much this depends on a reduced GFR, altered tubular function or the presence of proteinuria. Since CKD is often accompanied by tubular and interstitial dysfunction, we explore here for the first time the potential role of the tubular and tubulointerstitial compartments in cognitive dysfunction. To help address this issue, we have selected a group of primary tubular diseases with preserved GFR, in which to review the evidence for any association with brain dysfunction. Cognition, mood, neurosensory, and motor disturbances are not well characterized in tubular diseases, possibly because they are subclinical and less prominent than other clinical manifestations. The available literature suggests that brain dysfunction in tubular and tubulointerstitial diseases is usually mild and is more often seen in disorders of water handling. Brain dysfunction may occur when severe electrolyte and water disorders in young children persist over a long period of time before the diagnosis is made. We have chosen as examples to highlight this topic, Bartter and Gitelman syndromes and nephrogenic diabetes insipidus. We discuss current published findings, some unanswered questions, and propose topics for future research.

Isometric agonist and antagonist muscle activation interacts differently with 140-Hz transcranial alternating current stimulation aftereffects at different intensities

During transcranial electric stimulation, increasing intracellular Ca²⁺ levels beyond those needed for inducing long term potentiation (LTP) may collapse aftereffects. State-dependent plastic aftereffects are reduced when applied during muscle activation as compared with rest. Cortical surround inhibition by antagonistic muscle activation inhibits the center-innervated agonist. The objective of this study is to determine the interaction of state dependency of transcranial alternating current stimulation (tACS) aftereffects at rest and under activation of agonist and antagonist muscles during stimulation with different intensities. In 13 healthy participants, we measured motor-evoked potential (MEP) amplitudes before and after applying tACS at 140 Hz over the motor cortex in nine single-blinded sessions using sham, 1 mA, and 2 mA stimulation intensities during rest and activation of agonist and antagonist muscles. During rest, only 1 mA tACS produced a significant MEP increase, whereas the 2 mA stimulation produced no significant MEP size shift. During agonist activation 1 mA did not induce MEP changes; after 2 mA, first a decrease and later an increase of MEPs were observed. Antagonist activation under sham tACS led to an inhibition, which was restored to baseline by 1 and 2 mA tACS. Increasing stimulation intensity beyond 1 mA does not increase excitability, compatible with too strong intracellular Ca²⁺ increase. Antagonist innervation leads to MEP inhibition, supporting the concept of surround inhibition, which can be overcome by tACS at both intensities. During agonist innervation, a tACS dose-dependent relationship exists. Our results integrate concepts of "leaky membranes" under activation, surround inhibition, intracellular Ca²⁺ increase, and their role in the aftereffects of tACS.NEW & NOTEWORTHY Stimulation intensity and activation of center versus surround muscles affect cortical excitability alterations generated by 140-Hz tACS. At rest, excitatory aftereffects were induced by tACS with 1 mA, but not 2 mA stimulation intensity. With agonistic muscle activation, excitability first decreases, and then increases with 2 mA. For antagonist activation, the MEP amplitude reduction observed in the sham condition is counteracted upon by 1 and 2 mA tACS. This reflects the relation of LTP-like aftereffects to Ca²⁺ concentration alterations.

Diagnosis and management of hypocalcemia

The aim of this clinical narrative review is to summarize and critically appraise the literature on the differential diagnosis of hypocalcemia and to provide its correct management. Calcium is essential for muscle contraction and neurotransmitter release, but clinical manifestations of hypocalcaemia (serum calcium level <8 mg/dl; 2.12 mmol/L) may involve almost any organ and system and may range from asymptomatic to life-threating conditions. Disorders causing hypocalcemia can be divided into parathyroid hormone (PTH) and non-PTH mediated. The most frequent cause of hypocalcemia is postsurgical hypoparathyroidism, while a more comprehensive search for other causes is needed for appropriate treatment in the non PTH-mediated forms. Intravenous calcium infusion is essential to raise calcium levels and resolve or minimize symptoms in the setting of acute hypocalcemia. Oral calcium and/or vitamin D supplementation is the most frequently used as treatment of chronic hypocalcemia. In hypoparathyroidism, providing the missing hormone with the use of the recombinant human (rh) PTH(1-84) has been recently approved both by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA). This new therapy has the advantage of being effective for correcting serum calcium levels and significantly reducing the daily requirements of calcium and active vitamin D supplements. However, due to the high cost, a strict selection of candidates to this therapy is necessary. More challenging is the long-term hypocalcemia treatment, due to its associated complications. The development of long-acting recombinant human PTH will probably modify the management of chronic hypoparathyroidism in the future.

Acute psychosis secondary to suspected hyperparathyroidism: A case report and literature review

Introduction:

Hyperparathyroidism begins as a benign disease that is often left undetected unless the patient presents with severe symptoms. Often, the first sign of hyperparathyroidism is elevation in serum calcium.

Case Description:

A 38-year-old man presented with new onset acute psychosis. Laboratory testing revealed co-occurring untreated hyperparathyroidism.

Discussion:

A literature search was performed using PubMed to identify articles published in English with the following key terms: “hyperparathyroidism,” “psychosis,” and “hypercalcemia.” A review of findings follows the case report. Despite a thorough literature review, any pathophysiological explanation for psychiatric manifestations of hyperparathyroidism remains hypothetical.

No beneficial effects of vitamin D supplementation on muscle function or quality of life in primary hyperparathyroidism: results from a randomized controlled trial

CONTEXT

Impairments of muscle function and strength in patients with primary hyperparathyroidism (PHPT) are rarely addressed, although decreased muscle function may contribute to increased fracture risk.

OBJECTIVE

We aimed to assess the changes in muscle strength, muscle function, postural stability, quality of life (QoL), and well-being during treatment with vitamin D or placebo before and after parathyroidectomy (PTX) in PHPT patients.

DESIGN

A randomized placebo-controlled trial.

PATIENTS

We included 46 PHPT patients, mean age 58 (range 29-77) years and 35 (76%) were women.

INTERVENTIONS

Daily treatment with 70 μg (2800 IU) cholecalciferol or placebo for 52 weeks. Treatment was administered 26 weeks before PTX and continued for 26 weeks after PTX.

MAIN OUTCOME MEASURES

Changes in QoL and measures of muscle strength and function.

RESULTS

Preoperatively, 25-hydroxyvitamin D (25OHD) increased significantly (50-94 nmol/l) compared with placebo (57-52 nmol/l). We did not measure any beneficial effects of supplementation with vitamin D compared with placebo regarding well-being, QoL, postural stability, muscle strength, or function. In all patients, we measured marked improvements in QoL, well-being (P<0.01), muscle strength in the knee flexion and extension (P<0.001), and muscle function tests (P<0.01) after surgical cure. Postural stability improved during standing with eyes closed (P<0.05), but decreased with eyes open (P<0.05).

CONCLUSIONS

Patients with PHPT and 25OHD levels around 50 nmol/l did not benefit from vitamin D supplementation concerning muscle strength, muscle function, postural stability, well-being, or QoL. Independent of preoperative 25OHD levels, PTX improved these parameters.

Perioperative changes in cortical excitability, mood, and quality of life in patients with primary hyperparathyroidism: a pilot study using transcranial magnetic stimulation

OBJECTIVE

Serum calcium (Ca(2)(+)) and parathyroid hormone (PTH), amongst others, modify cortical excitability. Alterations in cortical excitability were shown in patients with epilepsy as well as hyper- or hypoparathyroidism. In patients with primary hyperparathyroidism (pHPT), preoperative elevated serum calcium and parathyroidectomy (PTx) may affect mood and quality of life. We hypothesized that perioperative changes in Ca(2)(+) and PTH in pHPT will affect cortical excitability and improve subjective health.

DESIGN AND METHODS

Transcranial magnetic stimulation (TMS) was performed before and after surgery in 15 pHPT patients. We measured resting motor threshold, cortical silent period (CSP), short intracortical inhibition, and intracortical facilitation. Health questionnaires were administered before, 1 day and 6 months after PTx, along with the disease-specific Pasieka's parathyroid assessment of symptoms (PAS), which was, to our knowledge, its first use in German.

RESULTS

SURGERY WAS SUCCESSFUL IN ALL PATIENTS. TMS-MEASUREMENTS REMAINED UNCHANGED WHEN ANALYZING ALL PATIENTS IN THIS PILOT STUDY. POSTOPERATIVELY, DEPRESSION DECLINED (P=0.05) AND QUALITY OF LIFE IMPROVED SIGNIFICANTLY (P=0.001) IN THE SF-36-SUBSCALES: vitality, social functioning, mental health and subjective health transition (post-hoc analysis). The PAS proved early relief of disease-specific symptoms (P<0.001).

CONCLUSIONS

We found unchanged cortical excitability comparing pre- and post-PTx in this pilot study. Mood and quality of life improved postoperatively. The German PAS is valuable in detecting disease-specific changes early after PTx.

Quality of life in patients with primary hyperparathyroidism

The clinical picture of primary hyperparathyroidism (PHPT) has changed over the last three decades and many asymptomatic patients are now diagnosed through the unexpected finding of high serum calcium levels. However, though not yet considered as typical features of the disease and therefore not included in the guidelines for surgery, many data are available on neuropsycological manifestations and their impact on quality of life in asymptomatic patients. PHPT patients indeed show early experience nonspecific symptoms, such as weakness, depression, sleep disturbance, memory loss and anxiety. Although the underlining mechanisms have not been still identified, the prevalence of psychiatric and cognitive deficits has been investigated in many studies, as well as the possible association with quality of life and well-being improvement after surgery. This article aims to review the current knowledge on quality of life in PHPT patients before and after surgery and the possible clinical implications of these findings.