- Clinical characteristics of magnet displacement according to the reason of migration.
| Author, year | Cause of migration | Cases (n) | Gender | Mean age (SD) (years) | MRI dose/indication | Head bandage/pain during the MRI | Clinical presentation | Clinical examination |
|---|---|---|---|---|---|---|---|---|
| Bawazeer et al 201918 | MRI | 1 | - | 28 | 1.5T | -/Y | Progressive neurologicalillness | - |
| Brian et al 201320 | MRI | 1 | Male | 4 | 1.5 T/Spine and brain tumor | Y/Y | - | - |
| Broomfield et al 201323 | MRI | 1 | Female | 64 | 1.5 T/spinal cord compression suspection | -/Y | Gait disturbance upper limb weakness | Bilateral skin reactions |
| Cuda et al 201326 | MRI | 1 | Male | 72 | 1.5 T/biliary duct pathology | Y/- | Pain and hotness | Focal skin alteration over the left inner coil |
| Demir et al 201932 | MRI | 1 | Female | 7 | 1.5 T/congenital scoliosis follow up | N/Y | Inability to use the implant due to a wound | Redness, wound scarring and edema on the implant body and magnet site |
| Deneuve et al 20086 | MRI | 1 | Male | 8 | 1.5 T/neurologic disorder progression | Y/Y | local erythema with edema and tenderness | local erythema, edema, tenderness, the magnet was outside the SR |
| Di Nardo et al 201231 | MRI | 1 | Female | 31 | 1.5 T/64-MHz brain MRI/mitochondrial myopathy sudden detorioation | N/Y | Pain and a burning sensation | Bulge in the receiver-stimulator |
| Epperson et al 201916 | MRI | 1 | Female | 10 | 1.5 T/central hypothyroidism suspection | Y/Y | Intermittent fever and tenderness over the processor/magnet site. | - |
| Leinung et al 202017 | MRI | 9 | Male (22%) | 37.2 (21.7) | Y (n=6)/- | Pain (4), swelling (5), redness (2), palpable displacement (3), inability to wear the CI processor (7) | ||
| Leong et al 20189 | MRI | 1 | Male | 67 | 1.5 T/suspected cervical and lumbar radiculopathy | Y/Y | Discomfort and a bulge | - |
| Kim et al 20157 | MRI | 1 | Female | 25 | 1.5 T/malignant ependymoma | Y/Y | - | - |
| Özgür et al 201936 | MRI | 1 | Male | 4 | 3 T/suspected diabetes insipidus | Y/Y | Swelling over the magnet site | The magnet had turned upside down, the external part was reversed (inside facing out) and still attracting the internal part. |
| Tam et al 202050 | MRI | 2 | Female | 36 and 74 | - | - | - | - |
| Young et al 201652 | MRI | 1 | Female | 11.6 | 1.5 T | Y/- | Discomfort and swelling of the soft tissue overlying the portion of the device. | - |
| Hassepass et al 201428 | 3 cases post-head trauma,19 cases post-MRI | 22 | - | - | - | - | - | - |
| Loundon et al 201046 | 1 case post-MRI, 2 cases post-head trauma | 3 | - | - | - | -/Y | - | - |
| Bhadania et al 201840 | Head trauma | 2 | - | - | - | - | - | - |
| Jiang et al 201643 | Head trauma | 1 | - | - | - | - | - | - |
| Keereweer et al 201433 | Head trauma | 1 | Male | 1.5 | - | - | The sound processor could no longer connect to the CI | Diffuse swelling without erythema of the skin overlying the CI. |
| Kim et al 200845 | Head trauma | 2 | Female | 4 and 6 | - | - | - | - |
| Mickelson et al 200834 | Head trauma | 1 | Male | 1.8 | - | - | - | The magnet was palpable anteroinferiorly. |
| Migirov et al 201047 | Head trauma | 3 | - | - | - | - | - | - |
| Nichani et al 2006 35 | 2 cases post head trauma2 unexplanied reasons, without history of apparent trauma | 4 | Male (100%) | 3 (82) | - | - | (2) erythema and swelling of the scalp over the RS site | (1) swelling over the magnet site(3) erythema and swelling of the scalp over the RS site. |
| Orhan et al 201248 | Head trauma | 2 | - | - | - | - | - | - |
| Stokroos et al 200712 | Head trauma | 1 | Female | 44 y | - | - | Known to have seizures | A slight bulge over the processor part of the implant and some local tenderness with a small, firm, palpable but less-well-defined mass. |
| Head trauma | 1 | Male | 3 y | - | - | Loss of the function of the implant | A slight bulge of the skin was visible over the implant site, and a small, firm swelling was felt over the processor part. | |
| Tarkan et al201351 | Head trauma | 1 | - | - | - | - | - | - |
| Wilkinson et al 200439 | Head trauma | 1 | Male | 13 m | - | - | No response in the external coil | - |
| Chan et al 201113 | No apparent trauma | 1 | Male | 4 y | - | - | Poor response to sound | Small and firm bulge over the processor part of the implant. |
| Qiu et al 201149 | Unexplained reasons | 1 | - | - | - | - | - | - |
| Raghunandhan et al 201037 | Unexplained reasons | 1 | Female | 13 y | - | - | Rapid deterioration in auditory verbal skills | A small boggy swelling in the mastoid region over the internal RS coil site. |
| Sefein et al 201844 | Associated with chronic suppurative otitis media | 1 | Male | - | - | - | - | - |
| Yun et al 200511 | Head trauma | 1 | Male | 70 m | - | - | - | Magnet was external to the SR by palpation. |
| No apparentcause | 1 | Male | 31 m | - | - | Swelling precludng use of the external device. | Ridge was palpable over the anterior body of the SR. Erythema without fluctuance | |
| Head trauma | 1 | Male | 28 m | - | - | Tender knot over the RS | Magnet was found to be freely mobile under the flap | |
| Wild et al 201038 | No apparentcause | 1 | Male | 34 m | - | - | - | Skin irritation over the implant site |
| Playing with magnetic toys | 1 | Female | 67 m | - | - | - | Dislocated magnet lateral to the receiver aerial | |
| Playing with magnetic toys | 1 | Female | 56 m | - | - | Dislocated magnet | - | |
Y, yes; N, no; y, years; m, months; CI, cochlear implant; RS, receiver-stimulator MRI; magnetic resonance imaging.