Olfactory Dysfunction, Olfactory Bulb Volume and Alzheimer's Disease: Is There a Correlation? A Pilot Study1.

BACKGROUND: Olfactory dysfunction is present since the earliest stage of Alzheimer's disease (AD). In AD patients, the olfactory impairment has been correlated with atrophy of some structures of the olfactory system, but the role of the olfactory bulb remains unclear. OBJECTIVE: The aim of our work is to test if patients suffering from AD exhibit a statistically significant reduction of the average volume of the olfactory bulb (OBV) compared to healthy subjects. METHODS: 78 subjects were enrolled in the study and divided into three groups: 28 healthy elderly (22 females, 6 males, mean age 69.4 ± 9.2), 25 patients with mild cognitive impairment (MCI) amnestic type (14 females, 11 males, mean age 74.5 ± 7.5), and 25 mild AD patients (14 females, 11 males, mean age 73.7 ± 6.8). Every subject underwent an MRI study of the olfactory bulb and an olfactory assessment with the Sniffin' Stick Extended Test. RESULTS: The statistical analysis showed no correlation between the OBV and MCI or AD. Moreover, olfactory function and OBV were not correlated in any of the three groups. CONCLUSION: The reduction of OBV does not seem to represent an index of neuronal damage in the earliest stages of AD.

Olfactory deficit and hippocampal volume loss for early diagnosis of Alzheimer disease: a pilot study.

BACKGROUND: The aim of this pilot study was to verify the role of olfactory test and volumetric magnetic resonance imaging measure of hippocampus to predict conversion from mild cognitive impairment to Alzheimer disease (AD). MATERIALS AND METHODS: Eighteen patients with amnesic mild cognitive impairment, broadly defined, were followed at 12 months. Hypothesized baseline predictors for follow-up conversion to AD were olfactory deficit and hippocampal volumes loss. RESULTS: In the 1-year follow-up, 5 patients converted to AD. The 2 clinical predictors olfactory test and hippocampal volume loss showed the same sensitivity of 92.3% but the olfactory test showed a higher specificity than the hippocampal volume loss (75% vs. 60%). CONCLUSIONS: Our findings suggest the potential utility of olfactory test and hippocampal volume loss for early detection of AD.

Fibrous dysplasia of the maxilla: diagnostic reliability of the study image. Literature review.

Objective Fibrous dysplasia (FD) is a benign bone disorder in facial bones. This study evaluates the possibility of diagnosing fibrous dysplasia on imaging alone, without biopsy of the lesion, which is often burdensome for the patient. Materials and Methods The authors bring their experience of four cases of bone lesions of the maxillofacial region and present a review of published studies. The imaging techniques evaluated are computed tomography (CT) and magnetic resonance imaging (MRI) with and without contrast. Results The literature review demonstrates that it is impossible to make diagnosis of fibrous dysplasia exclusively by imaging. Radiographic images often show a ground-glass appearance, which is characteristic but not pathognomonic of fibrous dysplasia. Conclusion Although CT and MRI images may in many cases suggest a diagnosis of fibrous dysplasia, histological examination or follow-up imaging should follow.

Role of genetic and acquired prothrombotic risk factors in genesis of sudden sensorineural hearing loss.

The methylenetetrahydrofolate reductase C677T mutation, factor V G1691A (factor V Leiden) mutation, prothrombin G20210A mutation and 8 other laboratory values associated with increased thrombotic risk were analyzed in 40 patients with sudden sensorineural hearing loss (SSHL). The results were compared with those obtained from 120 controls not affected by SSHL. We found a statistically significant higher frequency of hyperhomocysteinemia in the SSHL group compared with controls, and that this was also associated with the presence of homozygosity for the MTHFR C677T mutation. The study results suggest that SSHL might be caused, among other factors, by a combination of these 2 variables. We suggest that this analysis of the MTHFR C677T mutation should be further investigated to establish the etiology of SSHL, and that the same analysis should be taken into account in those patients with high levels of homocysteine.