BACKGROUND: Persistent post-COVID olfactory dysfunction continues to be studied due to the controversy in its pathophysiology and neuroimaging.
METHODS: The patients had confirmed mild COVID-19 infection with olfactory dysfunction of more than one month of evolution and they were compared to controls with normal olfaction, assessed using the Sniffin\' Sticks Olfactory Test and underwent brain, magnetic resonance imaging (MRI) of the olfactory bulb and olfactory function.
RESULTS: A total of 8 patients and 2 controls participated. The average age of the patients was 34.5 years (SD 8.5), and that of the controls was 28.5 (SD 2.1). The average score in the patients\' olfactory test was 7.9 points (SD 2.2). In brain and olfactory bulb MRI tests, no morphological differences were found. When evaluated by functional MRI, none of the patients activated the entorhinal area in comparison to the controls, who did show activation at this level. Activation of secondary olfactory areas in cases and controls were as follows: orbitofrontal (25% vs 100%), basal ganglia (25% vs 50%) and insula (38% vs 0%) respectively.
CONCLUSIONS: There were no observed morphological changes in the brain MRI. Unlike the controls, none of the patients activated the entorhinal cortex in the olfactory functional MRI.

BACKGROUND: In patients with COVID-19, olfactory dysfunction and anosmia have been reported, which in pregnant women occur in up to 24.2 %.
OBJECTIVE: To know the frequency at which pregnant women with SARS-CoV-2 infection have olfactory dysfunction.
METHODS: Age, gestational age, temperature, presence of nasal constipation or rhinorrhea, myalgia, headache, cough or chest pain were asked. Whether patients perceived and identified the scent of grape juice, coffee powder and menthol was evaluated. Central tendency and dispersion measures, frequencies and percentages were used. Sensitivity, specificity, positive and negative predictive value were calculated. Mann-Whitney\'s U-test and contrast of proportions were used for comparisons between groups.
RESULTS: There was a higher proportion of women with cough, headache, dyspnea, myalgia, odynophagia, rhinorrhea, chest pain, and anosmia in SARS-CoV-2-positive women. In patients without COVID-19, 88.9 % detected each one of the scents; only 31.8 % of the positive group detected grapes scent, 47.7 % coffee and 59.1 % menthol, which had the highest percentages of sensitivity (40 %), specificity (21 %), positive predictive value (59 %) and negative predictive value (11 %).
CONCLUSIONS: Olfactory dysfunction occurs in a significant percentage of pregnant women with COVID-19.
UNASSIGNED: En pacientes con COVID-19 se ha reportado disfunción olfatoria y anosmia; en la mujer embarazada se presenta hasta en 24.2 %.
UNASSIGNED: Conocer la frecuencia con la que las mujeres embarazadas e infección por SARS-CoV-2 tienen disfunción olfatoria.
UNASSIGNED: Se preguntó edad, edad gestacional, temperatura, presencia de constipación nasal o rinorrea, mialgias, cefalea, tos o dolor torácico, además de evaluar si las mujeres percibían e identificaban el aroma de jugo de uva, café en polvo y mentol. Se utilizaron medidas de tendencia central y dispersión, frecuencias y porcentajes. Se calculó sensibilidad, especificidad, valor predictivo positivo y negativo. La U de Mann-Whitney y el contraste de proporciones sirvieron para las comparaciones entre los grupos.
UNASSIGNED: Hubo mayor proporción de mujeres con tos, cefalea, disnea, mialgias, odinofagia, rinorrea, dolor torácico y anosmia en mujeres positivas a SARS-CoV-2. De las pacientes sin COVID-19, 88.9 % detectó cada uno de los aromas; solo 31.8 % del grupo positivo detectó el aroma a uva, 47.7 % el de café y 59.1 % el de mentol, el cual tuvo los porcentajes más altos en sensibilidad (40 %), especificidad (21 %), valores predictivos positivo (59 %) y negativo (11 %).
UNASSIGNED: la disfunción olfatoria se presenta en un porcentaje importante de las mujeres embarazadas con COVID-19.

Olfactory and taste dysfunction (OD, TD) have been considered symptoms of SARS-CoV-2 infection. However, its presence in certain populations, especially those with mild clinical symptoms, has not been clarified. The objective was to estimate the frequency of OD and TD, and its predictive validity in patients detected in Primary Care.
A cross-sectional study was carried out in the Spanish National Health System. An epidemiological survey was administered to patients who were requested the PCR test for SARS-CoV-2. Odds ratio (OR) were estimated to measure the magnitude of the association between OD and TD and the existence of SARS-CoV-2 infection. The sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of these symptoms in SARS-CoV-2 infection were calculated.
Of 1,038 patients screened, 20.1% had SARS-CoV-2 infection. OD and DG were present in 64.4% (95% CI 56.0-72.1) and 56.2% (95% CI 47.9-64.2) of the subjects with infection, respectively. The OR for OD was 12.2 (95% CI 8.26-18.06) and for TD was 7.95 (95% CI 5.48-11.53). TD presented a sensitivity of 41.1% (95% CI 34.4-46.1), a specificity of 91.9% (95% CI 89.8-93.7), a PPV of 56.2% (95% CI48.0-64.2) and a NPV of 86.1% (95% CI 83.6-88.3), while the OD showed a sensitivity of 45.0% (95% CI 37.6-51.5), a specificity of 93.7% (95% CI 91.8-95.0), a PPV of 64.4% (95% CI 56.0-72.1) and a NPV of 87.1% (95% CI 84.7-89.2).
More than half of the subjects with SARS-CoV-2 infection have OD or TD. The presence of OD or TD could be of diagnostic utility due to its ability to predict infection in more than half of the cases.

BACKGROUND: Hyposmia and substantia nigra hyperechogenicity (SN+) are characteristic markers of Parkinson\'s disease (PD), although their diagnostic value in isolation may be limited. We evaluated the combined prevalence of both disorders in patients diagnosed with PD and assessed their diagnostic yield compared to a sample with essential tremor (ET) and another group of healthy subjects.
METHODS: Patients diagnosed with PD and ET and treated in our outpatient clinic were enrolled. Olfaction was assessed using the \"Sniffin\' Sticks\" odour identification test (SS-12) and hyperechogenicity of the substantia nigra (SN+) was assessed by transcranial duplex ultrasound.
RESULTS: A total of 98 subjects were analysed, comprising 30 with PD, 21 with ET, and 47 controls. The respective prevalence rates of hyposmia (SS-12 < 8) and SN+ (area > .24cm(2)) were 70% and 83.3% in PD, 33.3% and 9.5% in ET, and 17% and 10.6% in controls. Both markers were present in 63% of patients with PD, none of the patients with ET, and only 2 of the controls.
CONCLUSIONS: Combined use of substantia nigra sonography and olfactory testing with SS-12, two rapid, safe, and accessible tests, was more specific than each isolated marker for distinguishing patients with PD from patients with ET and control subjects. Since both markers have been described in very early phases of PD, combined use may be helpful in providing early diagnosis of PD.