Table 2

- Clinical characteristics of magnet displacement according to the reason of migration.

Author, yearCause of migrationCases (n)GenderMean age (SD) (years)MRI dose/indicationHead bandage/pain during the MRIClinical presentationClinical examination
Bawazeer et al 201918MRI1-281.5T-/YProgressive neurologicalillness-
Brian et al 201320MRI1Male41.5 T/Spine and brain tumorY/Y--
Broomfield et al 201323MRI1Female641.5 T/spinal cord compression suspection-/YGait disturbance upper limb weaknessBilateral skin reactions
Cuda et al 201326MRI1Male721.5 T/biliary duct pathologyY/-Pain and hotnessFocal skin alteration over the left inner coil
Demir et al 201932MRI1Female71.5 T/congenital scoliosis follow upN/YInability to use the implant due to a woundRedness, wound scarring and edema on the implant body and magnet site
Deneuve et al 20086MRI1Male81.5 T/neurologic disorder progressionY/Ylocal erythema with edema and tendernesslocal erythema, edema, tenderness, the magnet was outside the SR
Di Nardo et al 201231MRI1Female311.5 T/64-MHz brain MRI/mitochondrial myopathy sudden detorioationN/YPain and a burning sensationBulge in the receiver-stimulator
Epperson et al 201916MRI1Female101.5 T/central hypothyroidism suspectionY/YIntermittent fever and tenderness over the processor/magnet site.-
Leinung et al 202017MRI9Male (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 20189MRI1Male671.5 T/suspected cervical and lumbar radiculopathyY/YDiscomfort and a bulge-
Kim et al 20157MRI1Female251.5 T/malignant ependymomaY/Y--
Özgür et al 201936MRI1Male43 T/suspected diabetes insipidusY/YSwelling over the magnet siteThe magnet had turned upside down, the external part was reversed (inside facing out) and still attracting the internal part.
Tam et al 202050MRI2Female36 and 74----
Young et al 201652MRI1Female11.61.5 TY/-Discomfort and swelling of the soft tissue overlying the portion of the device.-
Hassepass et al 2014283 cases post-head trauma,19 cases post-MRI22------
Loundon et al 2010461 case post-MRI, 2 cases post-head trauma3----/Y--
Bhadania et al 201840Head trauma2------
Jiang et al 201643Head trauma1------
Keereweer et al 201433Head trauma1Male1.5--The sound processor could no longer connect to the CIDiffuse swelling without erythema of the skin overlying the CI.
Kim et al 200845Head trauma2Female4 and 6----
Mickelson et al 200834Head trauma1Male1.8---The magnet was palpable anteroinferiorly.
Migirov et al 201047Head trauma3------
Nichani et al 2006 352 cases post head trauma2 unexplanied reasons, without history of apparent trauma4Male (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 201248Head trauma2------
Stokroos et al 200712Head trauma1Female44 y--Known to have seizuresA slight bulge over the processor part of the implant and some local tenderness with a small, firm, palpable but less-well-defined mass.
Head trauma1Male3 y--Loss of the function of the implantA slight bulge of the skin was visible over the implant site, and a small, firm swelling was felt over the processor part.
Tarkan et al201351Head trauma1------
Wilkinson et al 200439Head trauma1Male13 m--No response in the external coil-
Chan et al 201113No apparent trauma1Male4 y--Poor response to soundSmall and firm bulge over the processor part of the implant.
Qiu et al 201149Unexplained reasons1------
Raghunandhan et al 201037Unexplained reasons1Female13 y--Rapid deterioration in auditory verbal skillsA small boggy swelling in the mastoid region over the internal RS coil site.
Sefein et al 201844Associated with chronic suppurative otitis media1Male-----
Yun et al 200511Head trauma1Male70 m---Magnet was external to the SR by palpation.
No apparentcause1Male31 m--Swelling precludng use of the external device.Ridge was palpable over the anterior body of the SR. Erythema without fluctuance
Head trauma1Male28 m--Tender knot over the RSMagnet was found to be freely mobile under the flap
Wild et al 201038No apparentcause1Male34 m---Skin irritation over the implant site
Playing with magnetic toys1Female67 m---Dislocated magnet lateral to the receiver aerial
Playing with magnetic toys1Female56 m--Dislocated magnet-
  • Y, yes; N, no; y, years; m, months; CI, cochlear implant; RS, receiver-stimulator MRI; magnetic resonance imaging.