These results in a large group of patients confirm previous work. Apart from apparent success in 13 to 23% of patients, there is also a small but significant group of patients (7 to 9%) in whom olfactory function decreases after surgery. Because this decrease was mostly found in patients with relatively good preoperative olfactory function, this group should receive specific attention when counseling patients about the potential risks of nasal surgery.

Chemotherapy has a significant but transient effect on olfactory and gustatory function, possibly causing reduced appetite, a low energy intake, and weight loss. Additional spices and flavoring may compensate for this diminished chemosensory function, enhancing patient compliance and quality of life.

In many patients, local application of corticosteroids appears to have little or no positive effect on olfactory dysfunction, especially when considering long-term changes. Duration of disease, the patient's age/sex, or the presence of parosmia does not appear to predict the response to therapy with corticosteroids.

Olfactory dysfunction is a frequent nonmotor symptom in idiopathic Parkinson's disease (PD) and may be considered as an early clinical feature of the disease preceding motor symptoms by years. According to recent neuropathological staging concepts, impaired olfaction is assumed to indicate an early pathological process and might be associated with structural changes in the brain. A morphometric analysis of magnetic resonance images [voxel-based morphometry (VBM)] was used to investigate gray matter atrophy related to psychophysically measured scores of olfactory function in early PD patients (n ϭ 15, median Hoehn and Yahr stage 1.5), moderately advanced PD patients (n ϭ 12, median Hoehn and Yahr stage 2.5), and age-matched healthy controls (n ϭ 17). In PD patients, but not in controls, cortical atrophy in olfactory-related brain regions correlated specifically with olfactory dysfunction. Positive correlations between olfactory performance and gray matter volume were observed in the right piriform cortex in early PD patients and in the right amygdala in moderately advanced patients. The results provided first evidence that olfactory dysfunction in PD is related to atrophy in olfactory-eloquent regions of the limbic and paralimbic cortex. In addition, olfactory-correlated atrophy in these brain regions is consistent with the assumption that olfactory impairment as an early symptom of PD is likely to be associated with extranigral pathology.

ObjectiveUsing multidisciplinary treatment modalities the majority of children with cancer can be cured but we are increasingly faced with therapy-related toxicities. We studied brain morphology and neurocognitive functions in adolescent and young adult survivors of childhood acute, low and standard risk lymphoblastic leukemia (ALL), which was successfully treated with chemotherapy. We expected that intravenous and intrathecal chemotherapy administered in childhood will affect grey matter structures, including hippocampus and olfactory bulbs, areas where postnatal neurogenesis is ongoing.MethodsWe examined 27 ALL-survivors and 27 age-matched healthy controls, ages 15–22 years. ALL-survivors developed disease prior to their 11th birthday without central nervous system involvement, were treated with intrathecal and systemic chemotherapy and received no radiation. Volumes of grey, white matter and olfactory bulbs were measured on T1 and T2 magnetic resonance images manually, using FIRST (FMRIB’s integrated Registration and Segmentation Tool) and voxel-based morphometry (VBM). Memory, executive functions, attention, intelligence and olfaction were assessed.ResultsMean volumes of left hippocampus, amygdala, thalamus and nucleus accumbens were smaller in the ALL group. VBM analysis revealed significantly smaller volumes of the left calcarine gyrus, both lingual gyri and the left precuneus. DTI data analysis provided no evidence for white matter pathology. Lower scores in hippocampus-dependent memory were measured in ALL-subjects, while lower figural memory correlated with smaller hippocampal volumes.InterpretationFindings demonstrate that childhood ALL, treated with chemotherapy, is associated with smaller grey matter volumes of neocortical and subcortical grey matter and lower hippocampal memory performance in adolescence and adulthood.