Table 1.

Comparison of clinical, instrumental, and laboratory characteristics of patients.

Patient no.	Age and sex	Trigger	Time from the onset of symptoms	CNS or PNS clinical syndrome (diagnosis)	Clinical features	Spine MRI	EDX study	CSF analysis		Anti-ACE2 antibodies (U/mL) c	Therapy
								Ly (/µL) a	Prot (g/L) b
1	38, F	Anti-SARS-CoV-2 vaccine	7 days after vaccine injection	PNS (immune mediated radiculitis)	Weak DTR in LL, distal burning paresthesia and dysesthesia in LL	CE in the proximal portion of nerve roots D12 to L5 bilaterally	NCS: absent F-waves in deep peroneal nerve bilaterally	11	0.40	37.76	Methylprednisolone
2	60, M	SARS-CoV-2 infection	20 days after negative rRT-PCR assay	PNS (GBS)	Distal weakness in UL and LL, hypoesthesia and paresthesia with stocking-glove distribution, gait ataxia, and global areflexia	NP	NCS: demyelinating sensory-motor polyneuropathy in UL and LL	4	0.85	35.22	PEX
3	80, M	Anti-SARS-CoV-2 vaccine	30 days after vaccine injection	CNS (MRI-negative myelitis)	Neurological examination disclosed exaggerated deep tendon reflexes in the lower limbs, clonus of the right ankle, pyramidal hypertonia in the right lower limb, and spastic-ataxic gait, without sensory levels or Lhermitte’s sign	Spine MRI: no spinal cord abnormalities	Normal MEPs and NCS	NP	NP	37.33	Methylprednisolone
4	57, M	SARS-CoV-2 infection	15 days after negative rRT-PCR assay	CNS (MRI-negative myelitis)	Proximal weakness and bilateral pyramidal hypertonia in LL, hyperreflexia in LL, R ankle clonus, and paraparetic–spastic gait	Brain MRI: unremarkable; spine MRI: no spinal cord abnormalities	EMG and NCS: normal; SSEPs and MEPs: impaired central conduction in LL limbs bilaterally (prominent MEPs alteration in the R UL and LL)	3	0.81	37.47	IVIg§

ACE2, angiotensin-converting-enzyme 2; CE, contrast enhancement; CNS, central nervous system; CSF, cerebrospinal fluid; DTR, deep tendon reflexes; EDX, electrodiagnostic; EMG, electromyography; F, female; GBS, Guillain–Barré syndrome; IVIg, intravenous immunoglobulins (§2 g/kg over 5 days); LL, lower limbs; Ly, lymphomonocytes; M, male; MEPs, motor evoked potentials; MRI, magnetic resonance imaging; NCS, nerve conduction studies; NP, not performed; PEX, plasma exchange; PNS, peripheral nervous system; Prot, total proteins; R, right; rRT-PCR, transcription real-time PCR; SSEPs, cortical somatosensory evoked potentials; UL, upper limbs.

^aReference range, <5.

^bReference range, <0.52.

^cCutoff, 30 U/mL.