Rapid point-of-care detection of SARS-CoV-2 infection in exhaled breath using ion mobility spectrometry: a pilot study

BACKGROUND

An effective testing strategy is essential for pandemic control of the novel Coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Breath gas analysis can expand the available toolbox for diagnostic tests by using a rapid, cost-beneficial, high-throughput point-of-care test. We conducted a bi-center clinical pilot study in Germany to evaluate breath gas analysis using multi-capillary column ion mobility spectrometry (MCC-IMS) to detect SARS-CoV-2 infection.

METHODS

Between September 23, 2020, and June 11, 2021, breath gas measurements were performed on 380 patients (SARS-CoV-2 real-time polymerase chain reaction (PCR) positive: 186; PCR negative: 194) presenting to the emergency department (ED) with respiratory symptoms.

RESULTS

Breath gas analysis using MCC-IMS identified 110 peaks; 54 showed statistically significant differences in peak intensity between the SARS-CoV-2 PCR-negative and PCR-positive groups. A decision tree analysis classification resulted in a sensitivity of 83% and specificity of 86%, but limited robustness to dataset changes. Modest values for the sensitivity (74%) and specificity (52%) were obtained using linear discriminant analysis. A systematic search for peaks led to a sensitivity of 77% and specificity of 67%; however, validation by transferability to other data is questionable.

CONCLUSIONS

Despite identifying several peaks by MCC-IMS with significant differences in peak intensity between PCR-negative and PCR-positive samples, finding a classification system that allows reliable differentiation between the two groups proved to be difficult. However, with some modifications to the setup, breath gas analysis using MCC-IMS may be a useful diagnostic toolbox for SARS-CoV-2 infection.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov on September 21, 2020 (NCT04556318; Study-ID: HC-N-H-2004).

[Prospective monitoring of a university rheumatology outpatient clinic throughout the first wave of the COVID-19 pandemic : What lessons can be learned?]

Hintergrund

Im März 2020 breitete sich die SARS-CoV-2-Pandemie initial v. a. in Bayern aus. Zu diesem Zeitpunkt war weitgehend unklar, wie mit der immunmodulatorischen Therapie bei Rheumapatienten umzugehen ist.

Ziel der Arbeit

Das Ziel war es, den Einfluss der Pandemie auf klinische Entscheidungen zu erfassen.

Material und Methoden

Es wurden zwischen dem 16.03. und 31.07.2020 Patienten eingeschlossen, die sich in der Rheumaambulanz des Klinikums rechts der Isar vorstellten. Anpassungen der Therapie erfolgten nach klinischem Ermessen und in Anlehnung an die Handlungsempfehlungen der DGRh.

Ergebnisse

Es wurden 322 Patienten eingeschlossen. Die häufigsten Diagnosen waren die rheumatoide Arthritis mit 17 %, die ANCA-assoziierte Vaskulitis (AAV) mit 14 % sowie der SLE mit 12 %; 262 Patienten erhielten eine DMARD-Therapie und 77 Patienten orale Glukokortikoide. Es lagen 5 SARS-CoV-2-Verdachtsfälle vor. Kein Patient erkrankte nachweislich an COVID-19. Eine Therapieänderung erfolgte aufgrund der Pandemie bei 40 Patienten. Dabei kam es bei 3 Patienten zu einem Flare der Grunderkrankung. Eine Therapiedeeskalation erfolgte am häufigsten bei AAV, IgG4-assoziierter Erkrankung sowie bei gleichzeitig bestehenden Malignomen und beim Einsatz von Rituximab.

Diskussion

In dieser Single-Center-Kohorte legt das gänzliche Fehlen von nachweislichen SARS-CoV-2-Infektionen in einer sonst relativ stark betroffenen Region den Schluss nahe, dass kein überproportional erhöhtes Infektionsrisiko für Patienten mit entzündlich rheumatischen Erkrankungen zu bestehen scheint. Eine Fortführung der meisten immunsuppressiven Therapien erscheint daher sinnvoll.

4G versus 3G-enabled telemedicine in prehospital acute stroke care

Background

Time to reperfusion treatment is closely related to outcome in ischemic stroke. Prehospital stroke work-up in CT-equipped mobile stroke units is effective in reducing time to thrombolytic treatment. Current evidence predominantly comes from mobile stroke units staffed with neurologists but telemedicine-guided management may be acceptable for providing neurological expertise in ambulances. With unsatisfactory experiences in third-generation (3G)-based approaches, fourth-generation (4G) networks may provide adequate audio-visual quality but systematic comparisons of technological parameters and decision-making are lacking.

Methods

Trained actors presented stroke symptoms and paramedics assisted the remotely guided extended National Institutes of Health Stroke Scale (eNIHSS) assessment on the mobile stroke unit in Berlin, Germany. We compared technical parameters of 4G and 3G connections, assessed audio-visual quality of examination, and analyzed reliability of neurological assessment and treatment decisions made by the remote neurologist versus the mobile stroke unit neurologist.

Results

4G and 3G connections were evaluated in 40 scenarios each. Connectivity was not available in 17% of 4G- and 15% of 3G-attempts with 6% simultaneous unavailability of both networks. The remote examiners graded audio and video quality in 4G better than in 3G with slightly shorter assessment duration in 4G (mean: 9 (SD:5) vs. mean 11 (SD:3) min, p = 0.10). Reliability of the eNIHSS sum scores was high with intraclass correlation coefficients of 0.99 (95% CI: 0.987–1.00) for 4G and 0.98 (95% CI: 0.96–0.99) for 3G. None of the remote treatment decisions differed from onsite decisions.

Conclusions

4G mobile communications provided higher quality of video-examination and allowed reliable remote assessment of stroke symptoms but coverage was still incomplete in both networks.

Characterization of motor and somatosensory function for stroke patients

In a pilot study, stroke patients with a lesion related to the motor system were studied using magnetoencephalography (MEG) and electromyography (EMG). The patients performed sustained finger movements for 30 s followed by 30 s of rest and 20 repetitions of this sequence in total. Task-related cortical signals derived from MEG were observed here at very different frequency scales. Slow signals below 0.1 Hz were extracted by independent component analysis and are associated with the sustained activation of the motor cortex, the dcMEG motor activation. MEG-EMG coupling phenomena in the 10-30 Hz range were analyzed using the imaginary part of coherency and are attributed to cortico-muscular coupling driving the muscles. Additionally a signal from the somatosensory cortex due to an electrical stimulation at the wrist, the N20m, was recorded as a physiological marker. Field maps and time series associated with the three types of signals are presented for one patient and one control subject as the signal quality of the patient data was not sufficient to achieve a group result. The feasibility of a comprehensive electrophysiological measuring and analysis procedure of the motor function for stroke research is demonstrated by the results.

Non-esterified fatty acids impair insulin-mediated glucose uptake and disposition in the liver

AIMS/HYPOTHESIS

We investigated the effect of elevated circulating NEFA on insulin-mediated hepatic glucose uptake (HGU) and whole-body glucose disposal (M) in eight healthy male subjects.

METHODS

Studies were performed using positron emission tomography (PET) and [(18)F]-2-fluoro-2-deoxyglucose ([(18)F]FDG) during euglycaemic hyperinsulinaemia (0-120 min) and an Intralipid/heparin infusion (IL/Hep; -90-120 min). On a different day, similar measurements were taken during euglycaemic hyperinsulinaemia and saline infusion (SAL). Graphical and compartmental analyses were used to model liver data.

RESULTS

Circulating NEFA increased approximately three-fold during IL/Hep, and declined by 81+/-7% in the SAL study ( p</=0.01). Both M (-28+/-7%) and HGU (-25+/-9%) were significantly lowered by NEFA elevation ( p=0.004 and p=0.035 respectively). In the whole data set, the decreases in M and HGU were positively correlated ( r=0.78, p=0.038). No evidence of [(18)F]FDG outflow was detected during the scanning time. HGU was correlated with the phosphorylation rate parameter ( r=0.71, p=0.003) as derived by compartmental modelling.

CONCLUSIONS/INTERPRETATION

In healthy men, NEFA impair insulin-mediated HGU and whole-body glucose uptake to a similar extent. Our data suggest that multiple intracellular NEFA targets may concur to down-regulate glucose uptake by the liver.

Endoscopic treatment of a Zenker's diverticulum using argon plasma coagulation in a patient with massive cachexia and esophageal obstruction: a case report and review of literature

A case report is presented of an 86-year-old man in a very poor general condition with a 10-year history of a Zenker's diverticulum as a cause of a complete obstruction of the esophagus with subsequent aphagia and massive cachexia. Because of high surgical risk and contraindications to general anesthesia, an approach with the flexible endoscope to perform cricopharyngeal myotomy was undertaken. Several attempts with the flexible endoscope by experienced investigators had been performed until the esophageal inlet was intubated and argon plasma coagulation could be applied in several sessions to divide the tissue bridge between the esophagus and the Zenker diverticulum to successfully restore the pharyngoesophageal passage.

Characterization of vagal input to the rat esophageal muscle

There is recent morphological evidence for an interaction of autonomic nerve fibers and extrinsic motor nerves of the rat esophagus. The aim of the present study was to investigate a possible functional role of this autonomic innervation of vagal motor fibers on rat esophageal smooth and striated muscle function in vitro. The entire esophagus with both Nn vagi, including the Nn recurrentes, was dissected and placed in an organ bath with oxygenated Krebs-Ringer buffer. Contractile activity was measured in longitudinal direction with a force transducer. Both Nn vagi were placed on a bipolar platinum electrode 2 cm apart from the esophagus. Vagal stimulation, applied for 1 s (40 V, 0.5 ms, 20 Hz) resulted in a biphasic contractile response, which was completely blocked by tetrodotoxin (10(-6) M). The first part consisted of a tetanic striated muscle contraction, which was abolished by tubocurarin (10(-5) M) but unaffected by atropine (10(-6) M) or hexamethonium (10(-4) M). In contrast, the second part was completely abolished by hexamethonium (10(-4) M) and atropine (10(-6) M), whereas tubocurarine (10(-5) M) showed no influence, suggesting a stimulation of preganglionic nerve fibers supplying esophageal smooth muscle (muscularis mucosae). In order to characterize possible autonomic transmitters of the ENS of the esophagus, the following experiments were carried out. The magnitude of the striated muscle response was unaffected by VIP (10(-7) M), 5-HT (10(-6) M) and galanin (10(-8) - 10(-7) M), whereas they caused an inhibition of the smooth muscle response (VIP: -53.8 +/- 4.2%; galanin 10(-8) M: - 18.5 +/- 2.2%; 10(-7) M: -40.4 +/- 2.9%; 5-HT: -78.2 +/- 2.1%). The inhibitory effects of VIP and galanin on smooth muscle were reversible by the antagonists VIP 10-28 and galanin 1-15. In the presence of the nitric oxide synthase (NOS) inhibitor L-NNA (10(-4) M), the smooth and striated muscle contraction were not significantly influenced. Exogenous application of the NO-donor DEA-NO (10(-4) M) reduced the smooth muscle contraction by -81.6 +/- 7.4%, but had no significant effect on the striated muscle contraction. Though immunohistochemical findings are highly suggestive of an nitrergic autonomic modulation of striated muscle contraction by enteric neurons, we could not demonstrate a NO-mediated action on striated muscle activity. Therefore, the physiological relevance of the immunohistochemical findings remain unclear.

[Splenic thrombosis and celiac disease: a fortuitous association?]

BACKGROUND

Rare cases of venous thrombosis associated with celiac disease have been reported.

CASE REPORT

We report a case of 40-year-old woman with splenic infarction and splenic venous thrombosis associated with celiac disease. This patient was homozygous for the C677T mutation of the methyltetrahydrofolate reductase (MTHFR) gene and had moderately elevated homocysteinemia.

DISCUSSION

We discuss the link between celiac disease and thrombosis as well as the interest and appropriate duration of anticoagulation and hypothesize a mechanism of thrombotic disease in this setting with hyperhomocyseinemia.

Endomorphin-1 and -2, endogenous ligands for the mu-opioid receptor, inhibit striated and smooth muscle contraction in the rat oesophagus

Recently, morphological evidence for an interaction of autonomic nerve fibres and extrinsic motor innervation of the rat oesophagus has emerged. The aim of the present study was to investigate the possible influence of endogenous and exogenous opioids on rat oesophageal smooth and striated muscle function in vitro. The entire oesophagus (excluding the lower oesophageal sphincter) with both Nervi (Nn) vagi, including the Nn recurrentes, was dissected and placed in an organ bath (100 mL, 37 degrees) with oxygenated Krebs-Ringer buffer. Contractile activity was measured in a longitudinal direction with a force transducer. Both Nn vagi were placed on a bipolar platinum electrode 2 cm distant from the oesophagus. Vagal stimulation (VS), applied for 1 s (40 V, 0.5 ms, 20 Hz) resulted in a biphasic contractile response that was completely blocked by 10(-6) M tetrodotoxin. The first part consisted of a tetanic striated muscle contraction, as it was abolished by tubocurarine (10(-5) M, n=5) but unaffected by atropine (10(-6) M, n=3) or hexamethonium (10(-4) M, n=4). In contrast, the second part was completely inhibited by hexamethonium (10(-4) M) and atropine (10(-6)M), whereas tubocurarine (10(-5) M) showed no influence, indicating a stimulation of preganglionic nerve fibres supplying oesophageal smooth muscle (muscularis mucosae) via relays in myenteric ganglia. In order to characterize opioid influence on the oesophageal striated and smooth muscle contractility, the following experiments were carried out. 10(-6) M endomorphin-1 and -2, endogenous mu-opioid-receptor agonists, reduced the contractile response of the striated (EM-2, -25.1+/-5.3%; n=16), and the smooth muscle (EM-2, -81.9+/-3.3%; n=11). Both effects were reversible by the opioid receptor antagonist naloxone (10(-6) M) and therefore, mediated via opioid receptors. Neither SNC-80, an agonist on the delta-opioid-receptor, U-69593, an agonist on the kappa-opioid-receptor, nor nociceptin, an agonist at the ORL1 (opioid receptor-like) receptor, had a significant effect on the striated muscle contraction. In contrast to SNC-80, U-69593 and nociceptin inhibited smooth muscle contraction but this relaxation could not be antagonized by naloxone. None of the opioid receptor antagonists used had an effect on basal tonus or muscle contraction following VS. Our data provide evidence for an autonomic modulation of vagal motor innervation of the striated and smooth oesophageal muscle. Endomorphin-1 and -2, both selective mu-opioid receptor agonists, cause an inhibition of striated and smooth muscle response which is reversible by naloxone, an opioid receptor antagonist. The location of the mu-opioid receptor still has to be established.

A critical appraisal of the reporting of the National Acute Spinal Cord Injury Studies (II and III) of methylprednisolone in acute spinal cord injury

From the beginning, the reporting of the results of National Acute Spinal Cord Injury Studies (NASCIS) II and III has been incomplete, leaving clinicians in the spinal cord injury (SCI) community to use or avoid using methylprednisolone in acute SCI on the basis of faith rather than a publicly developed scientific consensus. NASCIS II was initially reported by National Institutes of Health announcements, National Institutes of Health facsimiles to emergency room physicians, and the news media. The subsequent report in the New England Journal of Medicine implied that there was a positive result in the primary efficacy analysis for the entire 487 patient sample. However, this analysis was in fact negative, and the positive result was found only in a secondary analysis of the subgroup of patients who received treatment within 8 hours. In addition, that subgroup apparently had only 62 patients taking methylprednisolone and 67 receiving placebo. The NASCIS II and III reports embody specific choices of statistical methods that have strongly shaped the reporting of results but have not been adequately challenged or or even explained. These studies show statistical artifacts that call their results into question. In NASCIS II, the placebo group treated before 8 hours did poorly, not only when compared with the methylprednisolone group treated before 8 hours but even when compared with the placebo group treated after 8 hours. Thus, the positive result may have been caused by a weakness in the control group rather than any strength of methylprednisolone. In NASCIS III, a randomization imbalance occurred that allocated a disproportionate number of patients with no motor deficit (and therefore no chance for recovery) to the lower dose control group. When this imbalance is controlled for, much of the superiority of the higher dose group seems to disappear. The NASCIS group's decision to admit persons with minor SCIs with minimal or no motor deficit not only enables statistical artifacts it complicates the interpretation of results from the population actually sampled. Perhaps one half of the NASCIS III sample may have had at most a minor deficit. Thus, we do not know whether the results of these studies reflect the severely injured population to which they have been applied. The numbers, tables, and figures in the published reports are scant and are inconsistently defined, making it impossible even for professional statisticians to duplicate the analyses, to guess the effect of changes in assumptions, or to supply the missing parts of the picture. Nonetheless, even 9 years after NASCIS II, the primary data have not been made public. The reporting of the NASCIS studies has fallen far short of the guidelines of the ICH/FDA and of the Evidence-based Medicine Group. Despite the lucrative "off label" markets for methylprednisolone in SCI, no Food and Drug Association indication has been obtained. There has been no public process of validation. These shortcomings have denied physicians the chance to use confidently a drug that many were enthusiastic about and has left them in an intolerably ambiguous position in their therapeutic choices, in their legal exposure, and in their ability to perform further research to help their patients.

[Subacute distal motor neuropathy disclosing malignant non-Hodgkin lymphoma: improvement under chemotherapy]

A non Hodgkin's lymphoma strictly located in the bone marrow, was discovered in a patient presenting with asymetric muscle weakness of upper and lower limbs. Both the lymphoma and the neurological syndrome were successfully treated with chemotherapy.

Depression following traumatic brain injury: a 1 year longitudinal study

A group of 66 patients hospitalized for the treatment of closed head injury, were assessed for the presence of mood disorders during their hospital admission and at 3, 6 and 12 months follow-up. A total 28 patients met DSM-III-R diagnostic criteria for major depression at some time during the study (17 in the acute stage, 11 during follow-up). The mean duration of major depression was 4.7 months. However, there appeared to be a group of transiently depressed patients (41%) who where depressed inhospital but were no longer depressed at 3 months follow-up. Throughout the follow-up period, major depression showed a strong relationship with poor social functioning. There was not, however, a consistent relationship between depression and quantitative measures of either physical or cognitive impairment. Location of the brain lesion was associated with the development of major depression only in the acute stage. Transient depressive syndromes were associated with left dorsolateral frontal and/or left basal ganglia lesions.

Comparison between acute- and delayed-onset depression following traumatic brain injury

Sixty-six patients admitted for the treatment of acute closed head injury were assessed for the presence of mood disorders during the in-hospital period and at 3-, 6-, and 12-month follow-ups. Diagnosis was made using a structured psychiatric interview and DSM-III criteria. A total of 28 patients had major depression at some time during the study: 17 had acute-onset depression and 11 had delayed-onset depression. Acute-onset depressions are related to lesion location and may have their etiology in biological responses of the injured brain, whereas delayed depressions may be mediated by psychosocial factors, suggesting psychological reaction as a possible mechanism.

Comprehensive predictions of outcome in closed head-injured patients. The development of prognostic equations

A comprehensive diagnostic evaluation was administered to 162 closed head-injured patients within 1 to 21 days (mean, 7.5 days) after injury. Each evaluation consisted of (1) power spectral analyses of electroencephalogram (EEG) recorded from 19 scalp locations referenced to age-matched norms, (2) brainstem auditory evoked potentials, (3) computed tomography (CT)-scan, and (4) Glasgow Coma Score (GCS) at time of admission (GCS-A) and at time of EEG test (GCS-T). Functional outcome at one year following injury was assessed using the Rappaport Disability Rating Scale (DRS), which measures the level of disability in the six diagnostic categories of (1) eye opening, (2) best verbal response, (3) best motor response, (4) self-care ability for feeding, grooming, and toileting, (5) level of cognitive functioning, and (6) employability. The ability of the different diagnostic measures to predict outcome at one year following injury was assessed using stepwise discriminant analyses to identify patients in the extreme outcome categories of complete recovery versus death and multivariate regression analyses to predict patients with intermediate outcome scores. The best combination of predictor variables was EEG and GCS-T, which accounted for 74.6% of the variance in the multivariate regression analysis of intermediate outcome scores and 95.8% discriminant accuracy between good outcome and death. The best single predictors of outcome in both the discriminant analyses and the regression analyses were EEG coherence and phase. A gradient of prognostic strength of diagnostic measures was EEG phase greater than EEG coherence greater than GCS-T greater than CT-scan greater than EEG relative power. The value of EEG coherence and phase in the assessment of diffuse axonal injury was discussed.

Pituitary pathology in Cushing's disease

Pituitaries of 137 cases with Cushing's disease were microscopically and immunohistologically studied. Many alterations and parameters (sex, age, anamnesis, cortisol plasma levels, tumor size, invasiveness, localization, differentiation of adenomas, immunohistological hormone content, capillarity, recurrences, peritumorous ACTH cell hyperplasia, and Crooke's cells) were analyzed and compared. Whereas most parameters were not correlated, we found some important statistically significant correlations: Undifferentiated adenomas are more frequently invasive than differentiated ones. Invasive adenomas recur more frequently than non-invasive adenomas. Extremely laterally localized adenomas are more often invasive. Larger adenomas are more frequently invasive than micro-adenomas. ACTH cell hyperplasia are more often demonstrable in specimens from total hypophysectomies (confined to our earlier series) than from partial hypophysectomies and adenomectomies. Recurrences of adenomas are more frequent in pituitaries with periadenomous ACTH cell hyperplasia. Very rarely ACTH cell hyperplasia are the only source of ACTH hyperfunction. The more Crooke's cells are demonstrable, the longer the post-operative replacement dose of Cortisol is required. Adenomas in Cushing's disease and adenomas in Nelson's syndrome differ significantly in the following points: Adenomas in Nelson's syndrome are larger and contain more plurinuclear cells. In the ultrastructure, adenomas in Cushing's disease show more cytofilaments. Paraadenomous Crooke's cells are lacking in Nelson's syndrome.

Use of titanium wire in cervical spine fixation as a means to reduce MR artifacts

MR imaging of the cervical spine is valuable for assessing traumatic injuries to the spinal cord and bony ligamentous structures. MR is also useful for detecting such long-term complications of spinal cord injury as syrinx, arachnoid cyst, cord adhesion, and persistent mechanical impingement on the spinal cord or spinal nerve roots. Treatment of cervical spine injuries that are mechanically unstable entails fixation and fusion. However, previous attempts at our institution to obtain clinically useful MR images of the cervical region after posterior wire fixation have failed because of image artifacts arising from ferromagnetic stainless steel wires. Use of biocompatible titanium wire for fixation allowed undistorted imaging of the spinal cord and spinal canal adjacent to the surgical fixation in a cadaver and in eight patients.

[A case of pheochromocytoma with cardiac localization. Review of the literature]

In a 26-year old man who died post-operatively, post-mortem examination revealed the presence of a phaeochromocytoma located in the atrio-ventricular sulcus and involving the trunk and bifurcation branches of the left coronary artery. Pre-operative investigations, including whole-body computerized tomography, and exploratory laparotomy had failed to detect the tumour. In contrast with the case reported here, the 4 other cases previously published concerned intrapericardial phaeochromocytomas in contact with the posterior wall of the left atrium.

Agenesis of the right diaphragm: repaired with marlex

A case of a female newborn with agenesis of the right hemidiaphragm is presented. The defect was corrected with a double sheet of Marlex, attached to a rim of endothoracic fascia and muscle. At the age of 5 yr, the child is in perfect health.

[Hereditary coproporphyria. 7 cases]

Hereditary coprophyria, known since 1955, is a rare variety of hepatic porphyria. The clinical picture is similar to that of acute intermittent porphyria with certain minor differences; neurological manifestations being rarer in particular. The essential biological characteristic is the massive excretion, in the urine and faeces, of coproporphyrins whilst the excretion of porphobilinogen and delta-amino-laevulinic acid is only slightly increased. As in acute intermittent porphyria, certain medications have an adverse effect, especially the barbiturates. The exact nature of the biochemical lesion is not understood but its hereditary nature has been demonstrated. 25 families have been reported in the literature up to the present time. The authors report two cases of hereditary coproporphyria with peripheral paralysis and respiratory failure, the outcome being fatal in one case. Study of the families led to the discovery of 3 other cases in the second family and 2 latent forms in the first.

[Primary hyperparathyroidism. Round calcification as a sign of cervico-mediastinal localization of a parathyroid adenoma]

The authors report the case of a man aged 59 years, with primary hyperparathyroidism; removal of a first adenoma, did not lead to recovery. Later, an egg-shell calcification was found together with a second large cervico-mediastinal parathyroid adenoma, the removal of which caused all the symptoms to disappear. After a review of other cases in the world literature with calcification of the parathyroid glands, the authors consider, before using more complicated techniques for preoperative localisation of parathyroid adenomas, one should carry out careful radiological examination of the cervical and mediastinal region. Under these conditions, one may detect significant calcifications which have escaped routine examination and may contribute to the topographic diagnosis of the parathyroid lesion sought.