[Olfactory dysfunction : Update on diagnosis and treatment]. / Riechstörungen : Update zur Diagnostik und Therapie.

Olfactory dysfunction is a common disorder, particularly in elderly people. From the etiologic point of view, we distinguish between sinunasal and non-sinunasal causes of dysosmia. As an important early symptom of neurodegenerative disease, dysosmia is particularly relevant in the diagnosis of Parkinson's or Alzheimer's disease. In addition to complete ENT examination and olfactory testing, e.g., with "Sniffin' Sticks", modern imaging procedures, e. g. MRI, are becoming more and more important for diagnostics, prognosis, and treatment decisions. Olfactory testing in children needs to be adapted to their shorter concentration span and limited range of known olfactory stimuli. Depending on the etiology, olfactory training, antiphlogistic measures, and surgical procedures are most promising. In cases of intracranial causes of dysosmia, neurosurgeons should know and respect anatomic structures of the olfactory signal pathway, not least for long-term prognosis.

[Dysosmia : current aspects of diagnostics and therapy]. / Riechstörungen : Aktuelles zur Diagnostik und Therapie.

Olfactory dysfunction is a common disorder, especially in elderly people. From the etiological point of view a differentiation is made between sinunasal, traumatic and non-sinunasal causes of dysosmia. Olfactory disorders are often observed in neurodegenerative diseases, especially in patients with Parkinson's disease or Alzheimer's disease. Apart from an extensive medical history important diagnostic tools are a complete ear nose and throat (ENT) examination including nasal endoscopy and olfactory testing, for example, with "sniffin' sticks". For diagnostic purposes modern imaging procedures, such as magnetic resonance imaging (MRI) are becoming more and more important. For testing children, olfactory testing needs to be adapted and depending on the etiology, olfactory training, antiphlogistic and surgical procedures are the most promising therapeutic approaches. In cases of intracranial causes of dysosmia neurosurgeons should know and respect the anatomical structures of the olfactory signal pathway, not least for the long-term prognosis.

Rosette-forming glioneuronal tumor of the fourth ventricle in an elderly patient.

Rosette-forming glioneuronal tumor of the fourth ventricle (RGNT) is a rare condition, which previously has been described predominantly in middle-aged patients. There is limited experience with this kind of tumor in the elderly. Clinical, neuroimaging, and histological features of an example in a 70-year-old male who presented initially with vertigo are detailed and compared with published cases. Neuroimaging studies demonstrated a 4-cm cystic lesion in posterior fossa containing a 1-cm contrast-enhancing nodule on its lateral margin. The lesion was confined to the fourth ventricle and initially thought to be a hemangioblastoma until angiography clarified the minimal tumor vascularization. Gross total resection was achieved. Pathological examination showed a rosette-forming low grade tumor with a cell proliferation rate of 2% being consistent with RGNT. The postoperative course was uneventful and clinical symptoms resolved completely. There was no tumor recurrence after 2 years follow-up. We confirm that the rare and only recently characterized tumor entity of RGNT can also be found in elderly patients; furthermore, it can be associated with a benign course. The main differential diagnosis of RGNT resulting from CNS-imaging modalities in elderly patients are pilocytic astrocytoma and hemangioblastoma of the posterior fossa, which after metastasis are the most common primary adult intra-axial posterior fossa tumors. Therefore, a subtle preoperative radiological diagnosis is warranted and surgery should be performed by experienced hands to avoid neurological deterioration.

[Importance of preoperative and intraoperative imaging for operative strategies]. / Bedeutung der prä- und intraoperativen Bildgebung für die operative Strategie.

Recent advances in preoperative and postoperative imaging have an increasing influence on surgical decision-making and make more complex surgical interventions possible. This improves the possibilities for frequently occurring challenges and promoting improved functional and oncological outcome. This manuscript reviews the role of preoperative and intraoperative imaging in surgery. Various techniques are explained based on examples from hepatobiliary surgery and neurosurgery, in particular real-time procedures, such as the online use of augmented reality and in vivo fluorescence, as well as new and promising optical techniques including imaging of intrinsic signals and vibrational spectroscopy.