Review Article

Post-COVID-19 Vaccination CNS Magnetic Resonance Imaging Findings: A Systematic Review

Table 1

Post-COVID-19 vaccination CNS MRI findings.

Author (year)VaccinePast medical historyGender/ageDiseasesOnset symptomsMRI findings

D’Agostino et al. (2021) [22]ChAdOx1 (AstraZeneca)NAF/54CVSTLeft side signs(i) Acute basilar thrombosis associated with the superior sagittal sinus thrombosis with the delineation of hyperacute ischemic lesions in the vascular territory of the right posterior cerebral artery and of the perforating pontine branches
(ii) Acute ischemic lesion with restricted diffusion involving the pons, mesencephalon, the right superior cerebellar hemisphere with the vermis, and the right posterior temporal lobe

Jamme et al. (2021) [23]ChAdOx1 (AstraZeneca)HTNF/69CVSTHeadache associated with behavioral symptoms unconscious(i) Bilateral frontal hemorrhage with brain herniation aggravating a cerebral venous thrombosis of the left internal jugular vein, sigmoid sinus, and superior sagittal sinus

Dutta et al. (2021) [24]ChAdOx1 (AstraZeneca)NAM/51CVSTHeadache and vomiting(i) Extensive venous collaterals in the superior sagittal sinus and transverse sinus observed in MRV

Ikenberg et al. (2021) [25]ChAdOx1 (AstraZeneca)NAF/30CVSTMild myalgia, a holocephalic headache, and chills(i) CVST of the left transverse and sigmoidal sinus with a left-temporal and left-cerebellar intracerebral hemorrhage

Wang et al. (2021) [26]ChAdOx1 (AstraZeneca)NAF/41CVSTFever, headache, pain, and swelling erythema on bilateral palms(i) The focal T1-w intermediate-signal-intensity and T2-w hyperintensity lesion within the posterior superior sagittal sinus
(ii) Filling defect within the posterior superior sagittal sinus

Syed et al. (2021) [27]mRNA-1273 (Moderna)DMM/45CVSTHeadaches and neck pain(i) Intracranial hemorrhage within the anterior left frontal lobe, bifrontal subarachnoid hemorrhage, and anterior superior sagittal sinus thrombosis

Yamaguchi et al. (2021) [28]Pfizer-BioNTechHyperuricemiaM/61CVSTHeadache and fever(i) Thrombosis in the superior sagittal sinus and the right transverse sinus

Braun et al. (2021) [29]ChAdOx1 (AstraZeneca)NAM/21CVSTFever and headache(i) Thrombosis of the superior sagittal sinus
(ii) Left-sided thrombosis in the internal jugular vein, sigmoid sinus, and lateral portion of the transverse sinus. Ischemia detected in the left cerebellar and the right high parietal and parieto-occipital cortex.

Finsterer and Nicset (2021) [30]Pfizer-BioNTechNAM/33CVSTHeadache in the left temporal region with nausea and vomiting(i) Venous sinus thrombosis of the left transverse and sigmoid sinuses

Nicolardi et al. (2022) [31]Pfizer-BioNTechNAM/56CVSTSevere asthenia, headache and acute confusional state(i) T2-w hyperintensity areas in both thalami
(ii) FLAIR: ischemic phenomena in thalami, left hippocampal, para hippocampal regions and central portion of splenium of the corpus callosum and hemorrhagic lesion in left para hippocampal region
(iii) SWI: heavy metal deposits in the aforementioned regions
(iv) PWI: low levels of CBF and CBV in affected areas

Qureshi et al. (2022) [32]Pfizer-BioNTechHTN, DM, CKD, essential tremors, anxiety, and depressionM/80CVSTHeadache, tinnitus, and visual disturbance(i) The MRV indicates a lack of blood flow in the left transverse sinus and left jugular vein within the cerebral venous sinuses

Elfil et al. [33]Ad26.COV2.S (Jcovden)NAM/28CVSTHeadache, blurry vision, diplopia, and photophobia(i) Filling defects within the superior sagittal sinus as well as the right transverse sinus extending into the right jugular vein

Bonato et al. (2021) [34]ChAdOx1 (AstraZeneca)NAF/26CVST and VITTHeadache, weakness, and visual disturbances(i) An extensive venous infarction with hemorrhagic transformation in the right parietal and left frontoparietal lobes
(ii) Multi-focal venous thrombosis, with bilateral blockage of the parietal cortical veins, straight sinus, vein of Galen, internal cerebral veins, and inferior sagittal sinus

Graf et al. (2021) [35]ChAdOx1 (AstraZeneca)NAM/29VITT with CVSTHeadache, abdominal pain, abdominal cramps, and hematemesis(i) Thrombosis of the left transverse and sigmoid sinuses, as well as the left proximal jugular vein

Wolf et al. (2021) [36]ChAdOx1 (AstraZeneca)NA(1) F/22VITT(1) Frontally accentuated headaches and a self-limited generalized epileptic seizure(1) Blood in the subarachnoid space adjacent to the falx cerebri on both sides. Thrombotic occlusion of the superior sagittal sinus, the left-hand transverse sinus, and the sigmoid sinus.
(2) F/46(2) Mild aphasia and hemianopia to the right(2) Thrombotic occlusion of the superior sagittal sinus and the left-hand transverse sinus and sigmoid sinus. An acute intracerebral hematoma in the left occipital lobe.
(3) F/36(3) Headache and somnolence with right-hand hemiparesis(3) Thrombotic occlusion of the straight sinus and a non-occlusive thrombus in the superior sagittal sinus. Congestive edema of both thalami with more pronounced on the left side.

Hsiao et al. (2022) [37]ChAdOx1 (AstraZeneca)NAF/40VITTChest pain, headache, and abdominal pain(i) MRV shows CVST

Goh Cy et al. (2022) [38]Pfizer-BioNTechNAM/76VITTLeft upper limb swelling(i) Acute left MCA thrombosis with infarction

Gattringer et al. (2022) [39]ChAdOx1 (AstraZeneca)NA(1) F/39VITT(1) Severe holocephalic headache(1) Left transverse sinus/sigmoid thrombosis but no brain parenchymal damage
(2) F/24(2) Severe persistent headache(2) Thrombosis, cortical veins, and a small frontal juxtacortical hemorrhage found on the right side of the brain

Yahyavi-Firouz-Abadi and Naik (2022) [40]Johnson & JohnsonNAF/30VITTWorsening head and neck pain(i) Large occlusive thrombus in the right transverse sinus extending to the right sigmoid sinus and jugular bulb

Jiang et al. (2022) [41]ChAdOx1 (AstraZeneca)Iron deficiency anemiaF/36VITTHeadaches accompanied by left upper limb clumsiness(i) T1-w hypointensity lesion at the right parietal lobe
(ii) T2-w FLAIR hypointensity lesion
(iii) SWI hypointensity “black dots” at the right parietal lobe
(iv) An irregular contour of the right transverse sinus in MRV

Rodriguez et al. (2022) [42]Johnson & JohnsonNAF/37VITTNeurological deterioration and right hemiplegia(i) Thrombosis of the major anterior part of the sagittal superior sinus with bilateral intraparenchymal hemorrhagic complications

Kania et al. (2021) [43]mRNA-1273 (Moderna)Atopic dermatitis and depressionF/19ADEMSevere headache, fever, back and neck pain with nausea and vomiting, and urinary retention(i) T2-w FLAIR hyperintense lesions in both brain hemispheres, pons, the medulla oblongata, and cerebellum. Few of them were contrast‐enhanced lesions.
(ii) T2‐w FLAIR widespread hyperintense area extended from medulla oblongata to T11 segment with overlapping few contrast‐enhancing lesions

Shimizu et al. (2021) [44]Pfizer-BioNTechDM and Alzheimer’s diseaseF/88ADEMImpaired consciousness, gaze, and evoked nystagmus(i) DWI, T2-w, and FLAIR hyperintensity of the middle cerebellar peduncles
(ii) CE MRI shows low signal intensity in the middle cerebellar peduncles

Nagaratnam et al. (2022) [45]ChAdOx1 (AstraZeneca)NAF/36ADEMBilateral optic neuritis, right-sided headache, photophobia, blurred vision, bilateral visual impairment, subjective color desaturation, painful eye movements, and fatigue(i) T2-w FLAIR hyperintensity lesions involving the subcortical WM, posterior limb of bilateral internal capsules, pons, and left middle cerebellar peduncle. The abnormal signal and enhancement of both optic nerves but more prominent on the left.

Yazdanpanah et al. (2022) [46]BIBP-CorV (Sinopharm)NAM/37ADEMProgressive weakness of 4 limbs, dysphagia, drooling, nausea, and vomiting. Symptoms of bilateral facial nerve paralysis.(i) T2-w FLAIR hyperintensity foci within the left corticospinal tract in the left cerebral peduncle, right and left sides of the pons, and medulla
(ii) Post-contrast T1-w: small enhancement in some of the lesions
(iii) DWI: significant restriction at the level of the pons
(iv) MRS: demyelination process by the presence of myoinositol and choline peaks

Poli et al. (2022) [47]Pfizer-BioNTechNAM/65ADEM, ocular myasthenia gravis, and autoimmune thyroiditisMild left-sided hemiparesis, contralateral dissociated sensory loss, dizziness, right-sided deafness, binocular horizontal diplopia, and ptosis of the right eye(i) Multiple acute inflammatory contrast-enhancing periventricular and brainstem lesions with involvement of vestibulocerebellar tract and cochlear nuclei

Ahmad et al. (2022) [48]Pfizer-BioNTechHTN and anxietyF/61ADEMProgressive generalized weakness and AMS(i) Diffuse and near symmetric acute leukoencephalopathy process involving the deep WM extending downward through the brainstem into the cerebellar WM tracts

Garg et al. (2022) [17]ChAdOx1 (AstraZeneca)NAF/67ADEMAMS, progressive loss of memory and cognitive ability, subtle personality changes, inability to concentrate, and lethargy(i) Multiple nodular/oval T2-w FLAIR hyperintensities involving the deep and periventricular cerebral WM asymmetrically, corpus callosum, subcortical regions, bilateral middle cerebellar peduncles, bilateral cerebellar hemisphere, and left basal ganglia without any mass effect

Poli et al. (2023) [49]Pfizer-BioNTechADEM with two fully remitted episodes 10-11 years agoM/65ADEMMuscle weakness and numbness in all extremities(i) Multiple acute inflammatory contrast-enhancing periventricular and right-sided brainstem lesions

Mumoli et al. (2021) [50]ChAdOx1 (AstraZeneca)Allergic asthma triggered by pollenM/45ADEM anti-MOG antibody-positiveBilateral lower limb weakness, urinary retention, vertigo, fever, diffuse myalgia, and back pain(i) Brain: FLAIR images showed large asymmetric lesions of WM, basal ganglia, and cortical GM with asymmetric involvement of thalami. Additionally, there is a tumefactive lesion present in the left frontal lobe
(ii) Spine: STIR images showed large confluent lesions extending over multiple segments until conus

Matsumoto et al. (2022) [51]mRNA-1273 (Moderna)Intraductal papillary mucinous neoplasm and HTNF/68MOG antibody-associated disorderNumbness on the right side of face(i) T2-w FLAIR hyperintensity lesion on the right lateral pontine and trigeminal nerve, and a middle cerebellar peduncle lesion was seen

Dams et al. (2021) [52]ChAdOx1 (AstraZeneca)NAM/59MOG-antibody-associated LTEMParesthesia, gait disturbance, and urinary and rectal dysfunction(i) On STIR images, it was observed that there is longitudinal myelopathy affecting the cervical, thoracic, and lumbar spinal cord, but without any contrast enhancement. The conus was also involved.

Sepahvand et al. (2021) [53]BIBP-CorV (Sinopharm)DM, HTN, and ischemic heart diseaseM/71LTEMHemiparesis, left paresthesia in both hands, and urinary retention(i) Longitudinally extensive T2-w hyperintense lesion without gadolinium enhancement from cervico-medullary junction to C3 level predominantly on the left side of the spinal cord

Miyaue et al. (2021) [54]Pfizer-BioNTechHTN, HLP, and prostate cancerM/75LTEMAscending paresthesia, lower back pain, reduced sensation during urination and defecation, and severe weakness in both legs(i) T2-w longitudinally extensive hyperintense lesion from the lower thoracic to lumbar spine was seen

Esechie et al. (2022) [55]mRNA-1273 (Moderna)Metastatic small-cell lung cancer, HTN, BPH, and chronic back pain with placement of a spinal stimulatorM/58LTEMParalysis of the lower extremity and sensory loss from chest down with overflow incontinence(i) Enhancing lesions from C7-T7 concerning for LTEM

Erdem et al. (2021) [56]Sinovac-CoronaVacNAF/78ATMTetraparesis, paresthesias of bilateral upper extremities, and urinary retention(i) Extensive TM from the C1 to the T3 spinal cord segment

Hirose et al. (2021) [57]mRNA-1273 (Moderna)HTN, hyperuricemia, and alcoholic liver cirrhosisM/70ATMBilateral lower extremities hypoesthesia and mild paraparesis(i) T2-w: multiple high-intense areas located at the T1/2 and T5/6 vertebral levels with weak gadolinium enhancement
(ii) CE T1-w: focal weak gadolinium enhancement in the T2-w high-intense area

Eom et al. (2022) [58]Pfizer-BioNTech(1) HTN and DM(1) M/71ATM(1) Bilateral hand weakness and numbness in fingers(1) High signal intensity and multi-focal nodular enhancement with an ill-defined signal increase on T2-w from the C1 to C3 vertebrae
(2) NA(2) F/23(2) Tingling sensation in both thighs, weakness of both legs, and urinary retention(2) High signal intensity lesion without contrast enhancement at the anterior portion of the conus medullaris on T2-w

Alabkal et al. (2021) [59]Pfizer-BioNTechPancreatitis and recurrent urinary tract infectionsF/26TMSaddle anesthesia and bilateral paresthesias, numbness, and intermittent allodynia ascending the plantar aspects of the feet up the posterior legs(i) T2-w hyperintense and diffusely enhancing lesion at T5, in keeping with TM
(ii) Three non-specific small patchy T2-w hyperintense lesions within the supratentorial deep WM (right anterior frontal lobe, right frontal operculum, and left internal capsule) which were felt to be non-specific

Chen et al. (2022) [60]NANAM/39Concurrent vasculitis in vertebral bodies and partial TMWeakness of left lower limb and aberrant sensation of the left lower trunk and limb from T9 level to toes(i) T2-w high signal in vertebral bodies of T3-T7 and at T7 spinal cord indicating an acute demyelinating lesion

Chen et al. (2023) [61](1) ChAdOx1 (AstraZeneca)(1) DM, HTN, and HLP(1) F/56(1) Acute myelitis(1) Numbness with burning sensation in right lower limb below inguinal region(1) High T2-w from T10 to the upper L1 level with minimal faint enhancement. Old lacunar infarction of the bilateral corona radiata, bilateral basal ganglia, and corpus callosum.
(2) Pfizer-BioNTech(2) MDD(2) M/64(2) Vaccine-associated herpes simplex encephalitis(2) Fever, AMS, nausea, and vomiting(2) Hyperintensity in the bilateral cingulate gyrus

Chen et al. (2021) [62]Inactivated virus vaccineNAF/middle-agedNMOSDMild fever, vomiting, diarrhea, cough, dizziness, and unsteady walking(i) Area postrema and bilateral hypothalamus lesions

Umezawa et al. (2022) [63]Pfizer-BioNTechGBSF/52NMOSDNeck pain, weakness of the left arm and leg, numbness of the left hand, and impaired temperature sensation of the right leg(i) T2-w and FLAIR hyperintense lesions reached from the C1 to C6 level. Gd-enhancement lesion from the C3 to C5 level and left lateral fasciculus
(ii) T2-w and DIR hyperintense lesions in the area postrema and the obex of the medulla
Nistri et al. (2021) [64]1–4. ChAdOx1(AstraZeneca)1, 3, and 5–13. MS(1) M/45MS (relapse)(1) Dysesthesia in both legs(1) C3 lesion
5 and 6. mRNA-1273 (Moderna)2 and 4. NA(2) F/48(2) Visual acuity deficit from right eye(2) Enhancing lesion in corpus callosum and multiple WM unenhanced lesions in periventricular areas and in the mesial occipital lobe
7–16. Pfizer-BioNTech(3) F/54(3) Hypoesthesia below the T6 level(3) New enhancing lesion in the thoracic cord
(4) F/66(4) Visual disturbance and postural instability on the right limbs(4) Multiple hyperintense lesions in the supra and infratentorial WM, four of which are with contrast enhancement
(5) F/42(5) Slight weakness of the left upper limb(5) New brain lesion with contrast enhancement
(6) F/57(6) Severe motor deficit in both legs(6) New enhancing bulbar lesion
(7) F/49(7) Numbness on the left hand and left side of her head(7) C3 lesion with contrast enhancement
(8) M/39(8) Paresthesia on the left leg(8) New brain enhancing lesion
(9) F/39(9) Dysesthesia on the right hand and foot(9) Contrast enhancing lesion in the mesencephalon
(10) F/60(10) Fatigue and numbness in both legs(10) New enhancing brain lesion
(11) F/30(11) Language disturbance(11) New enhancing brain lesion with conspicuous edema
(12) F/58(12) Headache, balance disturbances, urinary incontinence, difficulties in walking, and dysphagia(12) Active lesion with ring enhancement in the left frontal WM
(13) F/34(13) Neck pain and hypoesthesia on the right arm(13) Three new brain enhancing lesions, one of which is indicated by the arrow
(14) F/35(14) Paresthesia on the left side of the body(14) Three new enhancing lesions in the left temporal lobe and one, indicated here, in the left centrum semiovale
(15) F/54(15) Right hemiparesis(15) Two new ring-enhancing lesions localized in the WM adjacent to the left frontal horn and in the left middle periventricular region
(16) F/37(16) Weakness on the right limbs(16) New enhancing lesions, one of which is tumefactive, localized in the WM of the left centrum semiovale

Etemadifar et al. (2022) [65]BIBP-CorV (Sinopharm)MSF/50Anti-NMDAR encephalitis, acute MS relapse, or a combination of bothMyalgia, precipitation, vomiting, leg weaknesses, ataxia, dizziness, fatigue, and mildly agitated with an ataxic gait(i) Multiple new plaques in periventricular, juxtacortical, and cortical areas

Khayat‐Khoei et al. (2022) [66]1, 2, and 6. mRNA-1273 (Moderna)1, 3, and 6. MS(1) F/351, 3, and 6. MS exacerbation(1) Right arm dysmetria and gait ataxia(1) T2-w hyperintense lesion in the right cerebellum enhanced with gadolinium
3, 4, and 5. Pfizer-BioNTech2, 4, and 5. NA(2) F/262 and 5. Relapsing-remitting of MS(2) Blurred vision and pain of right eye(2) Multiple T2-w hyperintense periventricular, subcortical, posterior fossa, and spinal cord lesions (two of the lesions enhanced, one each in the brain and spinal cord)
7. Isolated demyelinating syndrome(3) F/24(4) Neuromyelitis optica(3) Vision changes and pain of the right eye(3) Several new enhancing brain lesions without any optic MRI abnormalities
(4) M/64(7) Clinically isolated demyelinating syndrome(4) Paresthesias, urinary retention, constipation, and balance/gait difficulty(4) Longitudinally extensive high signal abnormalities with cord swelling in the thoracic spinal cord. Gadolinium-enhanced T1-w: patchy posterior lesion enhancement at T1/2-T5 and T9-T10/11
(5) M/33(5) Blurred vision of the left eye(5) Multiple T2-w WM signal abnormalities in the corpus callosum with extension into the left frontal and parietal WM, suggestive of demyelination
(6) F/44(6) Ascending numbness and right-sided weakness(6) Periventricular and juxtacortical T2-w lesions typical of MS. Spine MRI: a T2-w hyperintense thoracic spinal cord lesion.
(7) F/48(7) Pain of the right eye and balance/gait difficulty(7) Periventricular and juxtacortical T2-w lesions and a new gadolinium-enhancing lesion in the centrum semiovale, adjacent to the falx in the left cerebral hemisphere
(8) Three new T2-w hyperintense WM lesions

Czarnowska et al. (2023) [67]Johnson & JohnsonHTNM/33MSRight upper and lower extremities numbness(i) Several demyelinating lesions, T1-w: subcortical region of the right frontal lobe lesion with gadolinium enhancement
(ii) T2-w hyperintense lesion located in corpus callosum
(iii) T2-w hyperintense acute lesion consistent with demyelination at C4/5 and one smaller lesion at the level of C3/C4, without enhancement

Patel et al. (2021) [68]ChAdOx1 (AstraZeneca)NAM/37GBSBack pain and progressive ascending muscle weakness(i) Both sides thickened cauda equina nerve rootlets, especially at the S1 level
(ii) CE T1-w showed significant augmentation of both the conus medullaris and the ventral cauda equina nerve roots

Allen et al. (2021) [69]ChAdOx1 (AstraZeneca)(1) NA(1) M/54GBS(1) Distal dysesthesia in the feet and hands and facial weakness(1) CE subtle enhancement bilaterally in the distal facial nerves at the internal auditory canal. There was symmetric enhancement of the labyrinthine, tympanic, the labyrinthine, tympanic, and descending parts of the facial nerves showed symmetric enhancement
(2) HTN(2) M/55(2) Bilateral thigh paresthesias, numbness in the sacral and lumbar regions, and development of facial diplegia(2) CE enhancement of the facial nerve within the right internal auditory canal

Nishiguchi et al. (2021) [70]Pfizer-BioNTechDMM/71GBSHeadache and ocular pain(i) Minor venous dilation of the middle cranial fossa

Dang and Bryson (2021) [71]ChAdOx1 (AstraZeneca)NAM/63GBSLower back pain, bilateral facial weakness, lower limb weakness, and paresthesia(i) CE enhancement of the facial and oculomotor nerves bilaterally

Berrim et al. (2022) [72](1) Ad26.COV2.S (Jcovden)(1) M/80GBS(1) Dysphonia, paresthesia, and quadriparesis(1) Small vessel ischemic disease was noted
(2) Pfizer-BioNTech(2) M/62(2) Peripheral facial weakness and ascending paralysis(2) Diffuse enhancement of the left facial nerve

Kobayashi et al. (2022) [73]Pfizer-BioNTechNAF/46AEAcute-onset diplopia(i) Lesion on the dorsal pons across the midline

Rastogi et al. (2022) [74]ChAdOx1(AstraZeneca) and mRNA-1273 (Moderna)NAF/59AEUnsteady gait, incoordination, dizziness, binocular diplopia, perioral paresthesia, right hand numbness, and lethargy(i) CE T1-w showed multiple focal, poorly defined regions of contrast enhancement in the cerebral cortex, deep grey matter, brainstem, and cerebellum

Vences et al. (2022) [75]Pfizer-BioNTechDM and HTNM/72AENausea, vomiting, malaise, headache, fever, confusion, aggressiveness, and gait alterations(i) After first dose: T2-w hyperintense lesions at the bilateral straight frontal gyri, left cingulate, and insula
(ii) After second dose: T2-w FLAIR lower-volume lesions in the bilateral frontal lobes compared to that in the previous MRI and new hyperintense lesions, predominantly in the left temporal region

Vences et al. (2022) [76]BIBP-CorV (Sinopharm)NAF/33AEHeadache, the sensation of thermal rise, conciliation insomnia, and transitory episodes of environment disconnection(i) T2-w FLAIR shows small hyperintense non-specific demyelinating lesions at the periventricular region, internal capsule, and bilateral subcortical areas
(ii) Second MRI: in the T2-w FLAIR sequence shows well-defined focal hyperintense lesions at the bilateral caudate nucleus and demyelinating lesions at the bilateral subcortical areas

Zhang et al. (2023) [77]BIBP-CorV (Sinopharm)NAM/29AEHeadaches, dizziness, muscle soreness, weakness, psychomotor agitation, intermittent confusion, intractable hiccups, and decreased appetite(i) Abnormal signals in the splenium of the corpus callosum

Huang et al. (2022) [78]ChAdOx1(AstraZeneca)NAF/38Autoimmune encephalopathyAcute-onset amnesia, language disturbance, and seizure(i) DWI-MRI: a subacute infarction at the right internal capsule and irregular vascular contour
(ii) MRV: irregularity of vascular contour

Youn and Yang (2021) [79]Pfizer-BioNTechNAM/22CLOCCsFebrile sensation and headache around the eyes and forehead(i) An oval-shaped restricted diffusion in the corpus callosum with low ADC values and lack of contrast mediated enhancement

Poussaint et al. (2021) [80]Pfizer-BioNTechLyme diseaseM/12CLOCCsSevere headache and visual hallucinations(ii) The splenium of the corpus callosum revealed T2-w prolongation and lower diffusivity

Procaccini et al. (2022) [81]Pfizer-BioNTechNAF/51CLOCCsFever, weakness, headache, palpitations, malaise, and AMS(i) Single oval-shaped lesion located in the splenium of the corpus callosum, hyperintense signal on T2-w and FLAIR, and restricted diffusivity on DWI
(ii) The first follow-up MRI, after 17 days: a complete resolution of the lesion in the splenium of the corpus callosum and several small round-shaped WM hyperintensities on T2-w and FLAIR
(iii) At the second follow-up MRI after 67 days: brain findings remained unchanged

Ohara et al. (2022) [82]Pfizer-BioNTech(1) NA(1) M/23CLOCCs(1) Nausea, mild headache, and fever1 and 2 brain MRI:
(2) Mild mental retardation and depression(2) F/33(2) Disturbance and headache(i) Restricted diffusion in the splenium with low ADC values, and FLAIR: a high signal intensity lesion at the midline of the splenium of the corpus callosum

Blauenfeldt et al. (2021) [83]ChAdOx1 (AstraZeneca)Hashimoto’s thyroiditis and HTNF/60Acute ischemic strokeHeadache and persistent abdominal pain(i) DWI: completed infarction in the entire area supplied by the right MCA
(ii) MRA: occlusion of the right internal carotid artery

Elaidouni et al. (2022) [84]BIBP-CorV (Sinopharm)NAM/36Acute ischemic strokeNumbness in his left arm and legs with headaches, asymmetry of the face, and disturbance of consciousness(i) An extensive stroke ischemic in the superficial and deep right parietal territory with the onset of hemorrhagic rearrangement of the right basal ganglia

Rattanawong et al. (2021) [85]Sinovac-CoronaVacNAF/24Acute prolonged motor aura resembling ischemic strokeVisual disturbance, numbness and weakness of the left arm, and tingling sensation over the fingers in the left hand(i) MRA: mild irregularity of the left pericallosal artery

Suwanwela et al. (2022) [86]Sinovac-CoronaVacMigraineF/24Prolonged migraine aura resembling ischemic strokeTingling progress to numbness at left arm and leg, pulsatile headache in the left temporal(i) Mild irregularities of the pericallosal branch of the intracranial artery

Yoshida et al. (2021) [87]Pfizer-BioNTechAtrial fibrillation and osteoarthritisF/83Cardioembolic strokeLeft hemiplegia and left hemispatial neglectBrain MRI after first dose:
(i) DWI: acute infarction in the left insular cortex and corona radiata. T2-w: susceptibility vessel signs are seen in the left middle MCA. MRA: the left MCA is occluded at the proximal M1 segment.
Brain MRI after second dose:
(ii) DWI shows acute infarction in the right insular cortex, caudate, and corona radiate
(iii) T2-w: susceptibility vessel sign in the right MCA
(iv) MRA: the right MCA is occluded at the proximal M1 segment

Fotiadou et al. (2022) [88]Pfizer-BioNTechNAM/59Spinal cord ischemiaRight lower limb weakness accompanied by abdominal pain and progressing to paraplegia(i) T2-w hyperintensities extending from T6 level to conus medullaris and bilaterally symmetric circular high signal foci in the anterior horn cells of the spinal cord

Ancau et al. (2022) [89]ChAdOx1 (AstraZeneca)(1) Hypothyroidism and polymyalgia rheumatica(1) M/61AHEM(1) Fever, headache, apathy, and generalized seizure(1) FLAIR hyperintense lesions with hemorrhagic involvement of the basal ganglia on both sides of the brain
(2) NA(2) F/25(2) Cephalgia, thoracic back pain, mild weakness, and ascending numbness in the legs(2) A longitudinal edema with modest contrast enhancement and isolated central hemorrhage in thoracic spinal cord. WM abnormalities in both hemispheres, as well as localized amplification in the WM
(3) NA(3) F/55(3) Developed progressive nausea, dizziness, and meningism(3) In the right occipital and left frontobasal regions, many FLAIR hyperintense and hemorrhaging lesions were seen in the right parietal and temporal areas

Kits et al. (2022) [90]Pfizer-BioNTechRheumatoid arthritisM/53AHEMConfusion, unconsciousness, agitation, and snoring(i) Multiple cortical and subcortical lesions with high T2-w and FLAIR signal and ubiquitous petechial hemorrhages
(ii) Repeated MRI: development of widespread lesions in cortical GM, thalami, basal ganglia, corpus callosum, brainstem, and cerebellum. Multiple lesions, mostly in the GM, in the cervical and thoracic medulla.
(iii) After three weeks, cortical laminar necrosis, a decrease in brain swelling, and regional encephalomalacia appeared in addition to increasing bilateral confluent lesions with increased signal in FLAIR and DWI, possibly representing delayed demyelination

Finsterer and Korn (2021) [91, 92]mRNA-based SARS-CoV-2MI, HTN, HLP, and nephrolithiasisM/52Intracerebral bleedingSudden-onset difficulties with reading and speaking (aphasia)(i) T2-w and SWI: intracerebral bleeding in the left temporal lobe

Elnahry et al. (2021) [93]ChAdOx1 (AstraZeneca)NAF/32Optic neuropathyBlurring of vision in the left eye, superior field loss, and pain with eye movement(i) Brain, orbit, and spine MRI: significant enhancement of left optic nerve
Bagella et al. (2021) [94]ChAdOx1 (AstraZeneca)NAM/49Inflammatory demyelinating polyneuropathyAsymmetric bilateral facial weakness and paresthesias in the tongue and face(i) Enhancement of the facial nerves and of the cauda equina and lower thoracic nerve roots

Abbott et al. (2022) [95]ChAdOx1 (AstraZeneca)NA(1) F/68Acute small fiber neuropathy(1) Dysesthesias and altered temperature sensation on hands and feet extending proximally(1) Multiple perineural cysts attached to bilateral L5‐S2 nerve roots deemed incidental. Cystic dilatation of the distal spinal cord central canal.
(2) F/55(2) Bilateral neuropathic pain and paresthesias in the hands and feet. Cheeks, nose, and tongue numbness and paresthesias.(2) Prominent central canal within the spinal cord from C4/C5 to mid T1-w vertebral level

Shalabi et al. (2022) [96]Pfizer-BioNTechNAM/41Unilateral multiple cranial neuropathyDysphagia, hoarseness, right side hearing loss, and diplopia(i) Enhancement in the right auditory canal, which involved the VIIth and VIIIth CNs

Manea et al. (2021) [97]Pfizer-BioNTechNAM/29Cranial nerve palsiesLeft oculomotor, abducens, diplopia, trigeminal, facial and Bell’s palsies(i) Diffuse gadolinium enhancement in the intra-canalicular and labyrinthic portion of the left facial nerve, intra-cisternal course of the left trigeminal, and oculomotor nerve

Cellina et al. (2021) [98]mRNA-1273 (Moderna)NAF/36Bell’s palsyDeep left latero-cervical pain and stiffness, followed by the sensation of not holding liquids properly in the mouth(i) Facial and vestibulocochlear nerves entering the internal auditory meatus with regular morphology and thickness
(ii) CE T1-w: enhancement of the distal intra-canalicular and labyrinthine segments of the left VII nerve

Correa et al. (2021) [99]ChAdOx1 (AstraZeneca)(1) HTN(1) M/64(1) Ischemic stroke(1) Right superior and inferior limbs paresia(1) Acute ischemic stroke in the left basal ganglia region, with hyperintense signal on FLAIR, associated with restricted diffusion, on DWI, with a reduced signal on ADC
(2) NA(2) M/42(2) Facial nerve palsy(2) Pain in the left ear, left facial muscles weakness, paresis of the left forehead’s muscles, left lagophthalmos and labial hypomobility, and left peripheral facial nerve palsy(2) Gadolinium enhancement in the canalicular and labyrinthine portions of the left facial nerve and in the left geniculate ganglion
(3) NA(3) M/65(3) Myelitis(3) Tetraparesia(3) Cervical spine MRI shows a hyperintense lesion on STIR and on T2-w extending from C4 to C6 level, lateralized to the left portion of the spinal cord

Kulsirichawaroj et al. (2022) [100]Pfizer-BioNTechNAF/16Polyneuritis cranialisNumbness and drooping on the right side of her face(i) CE T1-w: abnormal enhancement of right cranial nerve VII at the canalicular and labyrinthine segments and the genu

Kizawa and Iwasaki (2022) [101]Pfizer-BioNTechHTN, HLP, and osteoarthritisF/75Amyloid β-related angiitis of the CNSFrontal headache, depression, aphasia, apraxia, and a gait disturbance(i) DWI: abnormal hyperintensity, suggesting cerebral infarctions in the left parietal and occipital lobes

Mahajan et al. (2023) [102](1) ChAdOx1 (AstraZeneca)(1) NA(1) M/38Immune-mediated demyelination of the CNS(1) Bilateral lower limbs with sensory loss and bladder disturbance(1) Bilaterally symmetrical T2-w and FLAIR hyperintensities within the corticospinal tracts, involving the posterior internal capsules and corona radiate. Bilaterally symmetrical, long segment, T2-w hyperintensities in the spinal cord tracts involving the dorsal columns and bilateral lateral corticospinal tracts, extending from the cervicomedullary junction till the conus. Bilateral trigeminal nerve nuclei and intraparenchymal trajectory of trigeminal nerves also showed T2-w FLAIR hyperintensities.
(2) COVAXIN(2) Hypothyroidism(2) M/50(2) Tingling sensation in both feet, which progressed to involve the legs, and difficulty in walking(2) Bilaterally symmetrical hyperintensities within the corticospinal tracts, involving the posterior internal capsules and corona radiata, and medullary pyramids, with long segment T2-w hyperintensities in the spinal cord tracts involving the dorsal columns and bilateral lateral columns, extending from the cervicomedullary junction till the conus. The bilateral intraparenchymal trajectory of trigeminal nerves and trigeminal nerve nuclei also showed T2-w FLAIR hyperintensities
(3) NA(3) NA(3) M/38(3) Progressive symmetric quadriparesis involving the lower limbs first and then progressing to the bilateral upper limbs(3) Bilaterally symmetrical hyperintensities in the posterior limbs of the internal capsule, the bilateral intraparenchymal pontine trigeminal nerves, and the bilateral lateral columns and the dorsal columns of the spinal cord

Garg et al. (2022) [103]ChAdOx1 (AstraZeneca)HTNF/56Tumefactive demyelinating brain lesionWeakness of the right upper and lower limbs(i) T2-w FLAIR hyperintensities involving the WM of the left parietal lobe and extending into the body of the corpus callosum

Shiraishi et al. (2022) [104]mRNA-1273 (Moderna)Enlargement of the left testicle leads to testicular seminomaM/32Paraneoplastic tumefactive demyelinationRight-sided motor and sensory impairment(i) High-intensity lesion in the left internal capsule then the brain lesion had enlarged and progressed to a tumefactive lesion

Roncati and Manenti (2022) [105]Vaxzevria (formerly COVID-19 Vaccine AstraZeneca)NAF/28Pituitary apoplexyLong-lasting tension-type headache and menstrual changes(i) Signal alteration (related to a hemorrhagic event) detected in the right half of the sella turcica
(ii) The gadolinium CE MRI: pituitary apoplexy presence
Gogu et al. (2022) [106]Ad26.COV2.S (Jcovden)DMM/45Tolosa–Hunt syndromeFever, headache, and respiratory symptoms(i) T2-w and FLAIR: perineural tissue extending into the left cavernous sinus; hypersignal in the left temporal lobe, the hippocampal, and para hippocampal
(ii) CE T1-w: an inflammatory process involving the left cavernous sinus and orbital apex with perineural enhancement surrounding the left optic nerve sheath. MRV: thrombus in the cavernous sinus.

Santilli et al. (2022) [107](1) Pfizer-BioNTechNA(1) F/14Multi-system inflammatory syndrome with overlapping neurological involvement(1) Episode of unresponsiveness to stimuli, catatonia, and inability to move followed by agitation and confusion
(2) Agitation and headache, followed by drowsiness
(i) T2-w hyperintensity in the splenium of the corpus callosum with restricted diffusion
(2) mRNA-SARS-CoV2(2) M/9

Li et al. (2022) [108]Sinovac-CoronaVacReceived the third injection of COVID-19 vaccine when the cold symptoms were not completely goneM/70Cervical Staphylococcus aureus infectionSevere neck and shoulder pain, accompanied by numbness and fatigue in the limbs(i) Abnormal signals in the spinal cord at the level of C3 to C6 vertebrae, cervical vertebra infection, resulting in cervical abscess compression on the cervical spinal cord

Zhang et al. (2023) [109]BIBP-CorV (Sinopharm)Eczema and renal calculusM/39Charcot–Marie–Tooth disease type 1 (CMTX1)Aphasia, asyndesis, dysphagia, and dyspnea(i) Bilateral, symmetrical, and restricted diffusion, with T2-w hyperintensities in the corpus callosum and supratentorial WM