xRead - Olfactory Disorders (September 2023)

20426984, 2022, 4, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/alr.22929, Wiley Online Library on [04/09/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

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INTERNATIONAL CONSENSUS ON OLFACTION

Benefit : Complete history and physical examination, with nasal endoscopy, guides the choice of appropriate diagnostic tests, helps avoid misdiagnosis, improves diag nostic accuracy, ensures that treatment is consistent with diagnosis, and guides patient expectations. Harm : Minimal discomfort during physical examina tion and nasal endoscopy. Cost : Minimal, although the cost of a doctor’s visit is dependent on the health care system. Benefits-harm assessment : Preponderance of benefit overharm. Value judgments :None. Policy level : Strong recommendation. Intervention : History-taking and basic physical exam ination are essential in the diagnosis of OD. Nasal endoscopy is additionally recommended to make an accu rate diagnosis, as when it is combined with patient history, it increases diagnostic accuracy and excludes alternative causes. B Imaging Classic workup of patients with OD relies on thorough medical history, clinical examination, and evaluation of OF. This workup allows for diagnosing OD and its etiol ogy in many patients. Additionally, imaging procedures are useful to better define the cause of OD, to rule out CNS dis ease processes including tumors, and to counsel patients regarding overall prognosis. In this review, we analyzed evidence for the use of diverse imaging modalities in patients with OD. CT of the paranasal sinuses There are four studies evaluating the usefulness of CT of the paranasal sinuses in patients with OD (Table VIII.2). All of these studies use noncontrast CT, viewed on bone window. Three studies (two case series and one prospective cohort study) found that CT was useful in identifying OC obstruction, in the context of obstructive OD, 1053 COVID 19–related OD, 1054 and OC syndrome. 1055 One retrospec tive study evaluated the usefulness of CT scan to diag nose OD resulting from sinonasal disease (SND), in com parison to clinical examination. 1056 This study found that CT could be useful in refining the diagnosis since it was able to both diagnose SND in 7% of patients with sus pected non-SND causes, as well as rule out SND in one third of patients with suspected SND, who then had normal CT imaging findings. Specifically, they found that 3% of patients with PIOD, 14% with PTOD, and 11% with IOD had signs of sinonasal inflammation. The authors therefore 1

propose that CT scans are useful in patients with suspected non-SND OD to diagnose a possible contributory compo nent of inflammatory olfactory loss. Indeed, identifying a conductive or an inflammatory cause underlying an olfac tory disorder is particularly important since these patients could benefit from known medical/surgical interventions directed at SND, possibly improving OF. Although CT imaging could provide valuable information, it has to be emphasized that conductive or inflammatory causes can also be identified, in a majority of patients, based on care ful medical history-taking and endoscopic examination. In these cases, adequate treatment will be proposed before CT imaging, according to available guidelines. 1057 CTscan (or other imaging, such as MRI) should be considered if the patient has unilateral pathology or suspicion of tumor or after failure of appropriate medical treatment. If tumor or malignancy is suspected, medical and imaging workup should be completed expeditiously. CT imaging for the evaluation and diagnosis of OD Aggregate grade of evidence : D (Level 3: one study; Level 4: three studies). Benefit : Potential identification of treatable obstruction of the OC or sinonasal disease. Harm : Minimal (low radiation dose using cone-beam CT). Cost : Moderate. Benefit-harm assessment : Relative balance of benefit and harm given low risk of imaging and yet low LOE. Value judgments : The question as to whether CT scan brings relevant additional information that will change the management and outcome of patients with normal endo scopic examination, or with OD from a clearly attributable cause (postinfectious or posttraumatic) remains unan swered and no recommendation can be made. In PTOD, CT scan can be considered for identifying bony sequalae (septal fracture, fracture to the cribriform plate) or when a CSF leak is suspected. When OD is suspected to be from sinonasal inflammatory causes, a CT scan is helpful in its confirmation. Policy level :Option. Intervention : In case of suspected OC syndrome or sinonasal disease causing OD, CT scan can be considered as an option to confirm the diagnosis. There is low-level evidence to support its use in other causes of OD. 2 Structural MRI Thirty-two studies assessing the morphology of olfactory pathways in patients with OD using structural MRI met our inclusion criteria (Table VIII.3: 12 prospective cohort studies; eight case series; 12 retrospective studies).