Anxiety is a relevant problem in dental practice. The Visual Analogue Scale for Anxiety (VAS‐A), introduced in dentistry in 1988, has not yet been validated in large series. The aim of this study is to check VAS‐A effectiveness in more than 1000 patients submitted to implantology. The VAS‐A and the Dental Anxiety Scale (DAS) were administered preoperatively to 1114 patients (459 males and 655 females, age 54.7 ± 13.1 years). Statistical analysis was conducted with Pearson correlation coefficient, the receiver operating characteristic (ROC) curve, and McNemar tests. A close correlation between DAS and VAS‐A was found (r = 0.57, P < .0001); the VAS‐A thresholds of dental anxiety and phobia were 5.1 and 7.0 cm, respectively. Despite a significant concordance of tests in 800 cases (72%), disagreement was found in the remaining 314 cases (28%), and low DAS was associated with high VAS‐A (230 cases) or vice versa (84 cases). Our study confirms that VAS‐A is a simple, sensitive, fast, and reliable tool in dental anxiety assessment. The rate of disagreement between VAS‐A and DAS is probably due to different test sensitivities to different components of dental anxiety. VAS‐A can be used effectively in the assessment of dental patients, using the values of 5.1 cm and 7.0 cm as cutoff values for anxiety and phobia, respectively.

Cerebral blood flow tests have increasingly been advocated for the confirmation of brain death (BD). Four-vessel angiography has been considered the most reliable investigation in the diagnosis of BD for >30 yrs, but it is invasive. 99mTc-HMPAO SPECT provides noninvasive, multiplanar imaging of brain tissue perfusion. The aim of this study was to check the reliability of SPECT compared with contrast angiography. Prospective, blind study. Neurointensive care unit of a university hospital. Consecutive clinically brain dead patients with flat electroencephalogram. BD was diagnosed according to Italian law. 99mTc-HMPAO SPECT and four-vessel angiography were performed in the same session; the rater of each investigation ignored the results of the other. Blood pressure, Spo2, and Peco2 were monitored throughout the study: any episode of hypoxia or hypotension caused exclusion of the patient from the study. Twenty brain dead patients were enrolled. The cause of BD was head injury in seven cases (35%), subarachnoid hemorrhage in seven (30%), spontaneous hemorrhage in one (10%), brain tumors in two (10%), stroke in two (10%), and thrombosis of the sagittal sinus in one (5%). Both angiography and SPECT confirmed BD in 19 of 20 patients: angiography showed the absence of filling of intracranial arteries, while SPECT showed a picture of “empty skull.” For the remaining patient, angiography showed slight and late filling of left vertebral, basilar, and posterior cerebral arteries, while SPECT showed faint traces of uptake in the posterior fossa on the right side and on the midline. For this patient, the tests were repeated 48 hrs later, and both showed the arrest of intracranial circulation, thus confirming BD. Our results confirm the reliability of SPECT in the diagnosis of BD; because SPECT is noninvasive, it is a good candidate for the “gold standard” of diagnosis.

Science exists to refute dogmas; nevertheless, dogmas may be introduced when undemonstrated scientific axioms lead us to reject facts incompatible with them. Several studies have proposed psychobiological interpretations of near-death experiences (NDEs), claiming that NDEs are a byproduct of brain functions gone awry; however, relevant facts incompatible with the ruling physicalist and reductionist stance have been often neglected. The awkward transcendent look of NDEs has deep epistemological implications, which call for: a) keeping a rigorously neutral position, neither accepting nor refusing anything a priori; and b) distinguishing facts from speculations and fallacies. Most available psychobiological interpretations remain so far speculations to be demonstrated, while brain disorders and/or drug administration in critical patients yield a well-known delirium in intensive care and anesthesia, the phenomenology of which is different from NDEs. Facts can be only true or false, never paranormal. In this sense, they cannot be refused a priori even when they appear implausible with respect to our current knowledge: any other stance implies the risk of turning knowledge into dogma and the adopted paradigm into a sort of theology.