In patients with PD, results obtained under the specific conditions used suggest that neuronal activity in the amygdala and hippocampus is reduced. Assuming an impact on olfactory-related regions early in PD, our findings support the idea that selective impairment of these brain regions contributes to olfactory dysfunction. Furthermore, neuronal activity in components of the dopaminergic, cortico-striatal loops appears to be upregulated, indicating that compensatory processes are involved. This mechanism has not yet been demonstrated during olfactory processing in PD.

Eustachian tube balloon dilation constitutes a safe and very promising treatment option for patients with Eustachian tube dysfunction based on early-outcome analysis. ETS and specifically tubomanometry appear promising as assessment tools but await validation for use in the diagnostic workup and outcome analysis after ETBD. The pathophysiologic mechanism of Eustachian tube balloon dilation remains unclear. Long-term analysis and stratification of patients are needed to better evaluate the definite value of Eustachian tube balloon dilation.

No abstract

Changes of olfactory function have been described in neurodegenerations such as Alzheimer and Parkinson diseases. Complex alterations of olfactory performance seem to be present in POAG patients as well.

The trigeminal and olfactory nerves share overlapping innervation areas in the nasal cavity and seem to work in an interactive way. Loss of olfactory function leads to a decreased trigeminal sensitivity, as shown in anosmic subjects. To report the impact of disturbed trigeminal sensitivity on the olfactory function, we present a patient with unilateral loss of trigeminal function resulting from a meningeoma. Thresholds to a selective olfactory stimulus were elevated by a factor of 64 on the affected side. Recordings of event-related potentials in response to olfactory stimuli showed a significantly reduced response on the affected side. This report indicates that loss of trigeminal function may affect the sense of smell.