Table 1.
Studies of anosmia with various etiologies: demographic information, clinical characteristics, and associated tests
| No. | MRI filed strength | Age, gender, and etiology | Duration of olfactory loss | Otorhinolaryngological evaluation | Psychophysical, physiological tests and questionnaire | Notes |
|---|---|---|---|---|---|---|
| Various etiology | ||||||
|
(Chung et al. 2018) Korea |
3T CX Philips 64-channel |
34 Pt. (15M/19F) 9–72 years CRS = 15 PIOD = 7 Trauma = 2 Idiopathic ` = 10 |
Mean = 59.2 months 2–552 months |
Nasal endoscopic |
Sniffin’ Sticks (Korean version) Sino-Nasal Outcome Questionnaire of Olfactory Disorder (QOD) |
|
|
(Hummel et al. 2015) Germany |
1.5T Signa Echospeed, GEMS |
378 Pt. (185M/193F) Mean age: 49 ± 14 CRS = 99 PIOD = 78 Trauma = 201 |
Nasal endoscopic Otorhinolaryngological investigation |
Sniffin’ Sticks | ||
|
(Goektas et al. 2009) Germany |
1.5T Symphony Vision |
10 Pt. PIOD = 3 Trauma = 4 Idiopathic ` = 3 |
Mean = 146 ± 203 7–600 months |
Nasal endoscopic | Sniffin’ Sticks | *Only anosmia Pt. were included in this study |
|
(Fonteyn et al. 2014) Belgium |
267 Pt. PIOD = 76 Trauma = 103 Idiopathic ` = 40 Congenital = 27 Toxic = 10 Neurological = 11 |
Sniffin’ Sticks |
Retronasal psychophysical performances were evaluated by the application of 20 standardized odorant powders on the mobile part of the patient’s tongue *Total participants were 469, but the rest is hyposmia |
|||
|
(Rombaux et al. 2006b) Belgium |
1.5T Sigma Echospeed GEMS |
33 Pt. PIOD = 11 (5M/6F) 27–63 years Trauma = 11 (5M/6F) 20–60 years NP = 11 (4M/7F) 35–60 years HC = 11 (5M/6F) 22–61 years |
Nasal endoscopic | Sniffin’ Sticks |
Retronasal Psychological performance was evaluated using 20 stimuli Stimulants were applied to the midline of the tongue |
|
| (Mueller et al. 2005) |
31 Pt. RVI = 22 (9 M/13 F) (mean age, 57 years) Trauma = 9 (7 M/2 F) (mean age = 52 years HC = 17 (4 M/13 F) (mean age = 49 years) |
3–108 months | Sniffin’ Sticks | Results are a combination of anosmia and hyposmia | ||
|
(Bitter et al. 2010b) Germany |
3.0T Magnetom TrioTim 12-channel |
17 Pt. (6M/11F) 19–64 years Mean age: 49.6 ± 13.8 PIOD = 4 Trauma = 5 Idiopathic ` = 8 17 HC (6M/11F) 22–65 years Mean age: 40.4 ± 14.9 *Right-handed |
12–252 months | Nasal endoscopic | Sniffin’ Sticks | |
|
(Peng et al. 2013) China |
3T Siemens Trio Tim Magnetom 8-channel |
19 Pt. (5M/14F) 28–57 years Mean age: 45.3 ± 10.2 PIOD = 13 Trauma = 4 Idiopathic ` = 1 20 HC (6M/14F) 24–59 years Mean age: 43.6 ± 14.8 *Right-handed |
2–240 months | Toyota and Takagi olfactometry | ||
|
(Rombaux et al. 2012) Belgium |
3T Philips Achieva 8-channel |
60 Pt. (21M/39F) 24–79 years Mean age: 50 PIOD = 28 Trauma = 32 |
Sniffin’ Sticks Retronasal psychophysical olfactory tests |
|||
| Idiopathic olfactory loss | ||||||
|
(Liu et al. 2018) China |
3T Siemens Trio Tim Magnetom 12-channel |
20 Pt. (8M/12F) 26–77 years Mean age: 44 ± 12 20 HC (8M/12F) 23–69 years Mean age: 44 ± 12 |
Mean = 26.4 months 4–96 months |
Nasal endoscopic and paranasal sinus examination |
Sniffin’ Sticks Toyota and Takagi olfactometry |
|
|
(Rombaux et al. 2010a) Belgium |
1.5T Signa Echospeed, GEMS |
22 Pt. (9M/13F) 31–78 years Mean age: 53.7 22 HC (9M/13F) 28–77 years Mean age: 52.00 |
Mean = 8.4 months 3–19 months |
Sniffin’ Sticks |
Retronasal psychophysical performances (R), using odorized powders presented to the oral cavity so that orthonasal olfactory stimuli were avoided Parosmia in three Pt |
|
|
(Yao et al. 2014) China |
3T Siemens Trio Tim Magnetom 12-channel |
16 Pt. (9M/7F) 29–61 years Mean age: 48.6 ± 9.9 16 HC 32–60 years Mean age: 52.5 ± 8.7 *Right-handed |
6–120 months | Nasal endoscopic |
Sniffin’ Sticks Toyota and Takagi olfactometry Mini-Mental-State-Examination |
|
| Upper respiratory tract infection (postinfectious olfactory loss) | ||||||
|
(Yao et al. 2018) China |
3T Siemens Trio Tim Magnetom |
19 Pt. (5M/14F) 21–50 years Mean age: 37.7 ± 8.4 20 HC (8M/12F) 22–49 years Mean age: 35.4 ± 7.9 *Right-handed |
Mean = 49.2 ± 31.2 months 6–104.4 months |
Nasal endoscopic |
Sniffin’ Sticks Toyota and Takagi olfactometry Mini-Mental-State-Examination |
|
|
(Rombaux et al. 2006a) Belgium |
1.5T Signa Echospeed, GEMS | 11 Pt. |
Mean = 6 months 1–15 months |
Nasal endoscopic Otorhinolaryngological investigation |
Sniffin’ Sticks | |
|
(Rombaux et al. 2009a) Belgium |
1.5T Signa Echospeed, GEMS | 122 Pt. but only 50 Pt. with OB measurement | Sniffin’ Sticks | |||
| Congenital anosmia | ||||||
| (Karstensen et al. 2018) |
3 T Siemens Magnetom Verio 32-channel |
17 Pt. (6M/11F) Mean age: 49.1 ± 13.8 16 HC (7M/9F) Mean age: 47.2 ± 16.1 |
*Taste, vision and hearing examination |
Sniffin’ Sticks MoCA |
||
| (Yousem et al. 1996b) |
3 Pt. (borderline function) |
Sinonasal endoscopic |
UPSIT Mini-Mental Status Examination |
*Total participants were 25, but the rest is hyposmia | ||
| (Frasnelli et al. 2013) |
1.5T Siemens Sonata 8-channel |
17 Pt. (11M/6F) Mean age: 40.30 ± 17.6 17 HC (5M/12F) Mean age: 39.2 ± 14.4 |
Sniffin’ Sticks | |||
|
(Huart et al. 2011) Brussels |
1.5T Signa Echo Speed (Brussel) 1.5T Siemens Magnetom Vision (Dresden) |
36 Pt. (12M/24F) Mean age: 38 7–79 years old 70 HC (34M/36F) Mean age: 36.5 7–72 years old |
Sniffin’ Sticks | |||
|
(Abolmaali et al. 2002) Germany |
1.5T Siemens Magnetom Vision |
21 Pt. (2M/19F) Mean age: 29 12–73 years old 8 HC (4M/4F) Mean age: 24 21–27 years old |
Sniffin’ Sticks | |||
|
(Peter et al. 2020) Sweden and Netherlands |
3T Siemens Magnetom Prisma 20-channel (Swedish) 3T Siemens Magnetom Verio 32-channel (Netherland) |
33 Pt. (13M/21F) (1 Pt. removed due to abnormal anatomy) 34 HC (12M/22F) |
Sniffin’ Sticks |
24/34 individuals with ICA had received a diagnosis from a physician 27/34 lacked bilateral OB 3/34 had identifiable (albeit small) OB 4/34 non-determinable due to the limited spatial resolution of 1 mm3 |
||
| Traumatic brain injury | ||||||
| (Han et al. 2018) |
1.5T Siemens Sonata 8-channel |
24 Pt. (15M/9F) Mean age: 53.7 ± 13.7 22 HC (17M/5F) Mean age: 45 ± 13.9 |
Mean = 32.2 ± 22 months | Sniffin’ Sticks | ||
| (Miao et al. 2015) |
26 Pt. (15M/11F) Mean age: 40.08 ± 10.70 21 HC (12M/9F) Mean age: 42.52 ± 11.64 *Right-handed |
Mean = 11.5 months 10 days–108 months |
Nasal endoscopic |
Sniffin’ Sticks Toyota and Takagi olfactometry |
Side of head trauma: occipital (19 Pt.) | |
| (Rombaux et al. 2006b) | 1.5T Signa Echospeed GEMS | 20 Pt. |
Mean = 14.9 months 3–60 months |
Nasal endoscopic |
Sniffin’ Sticks Psychophysical tests of olfactory function assessed both for the orthonasal (olfactory perception during sniffing) and retronasal routes perception during eating, drinking |
*Only anosmia Pt. were included in this study |
|
(Yousem et al. 1999) USA |
36 Pt. (21M/15F) Mean age: 36 ± 11.40 24 HC (12M/12F) Mean age: 39 ± 11.50 |
Mean = 52 months ± 95.6 | Nasal endoscopic |
UPSIT Picture Identification Test 30-item Mini-Mental Status Examination |
||
|
(Yousem et al. 1996a) USA |
25 Pt. (14M/11F) Mean age: 36 ± 9.80 |
3–183 months | Nasal endoscopic |
UPSIT Picture Identification Test 30-item Mini-Mental Status Examination |
||
|
(Jiang et al. 2009b) Taiwan |
1.5T Exite GEMS |
54 Pt. (32M/22F) 17–60 years Mean age: 39 30 HC (24M/6F) 20–79 years Mean age: 43.4 *Right-handed |
1–125 months | Nasal endoscopic | Phenyl ethyl alcohol (PEA) *odor detection threshold | |
| (Doty et al. 1997) |
148M Mean age: 40.4 ± 16.2 120F Mean age: 42.3 ± 17.8 |
UPSIT | ||||
Pt. patient, CRS chronic rhinosinusitis, RVI respiratory viral infection, IOL idiopathic olfactory loss, PIOD postinfectious olfactory dysfunction, NP nasal polyposis, HC healthy control, OB olfactory bulb, OS olfactory sulcus, GM gray matter, SFS superior frontal sulcus, MFG middle frontal gyrus, UPSIT University of Pennsylvania Smell Identification Test
*Sinonasal endoscopy was evaluated to exclude obstructive or inflammatory causes of smell dysfunction