Hoe Leong  SII

CASE REPORT:
We report a case of paraparetic spectrum of GBS in a 53-year-old lady who presented with rapidly progressive acute flaccid paralysis involving both lower extremities with areflexia eight days after the first dose of Sinovac vaccine for SARS-CoV-2 in Malaysia. Cerebrospinal fluid (CSF) albuminocytological dissociation was seen and nerve conduction study (NCS) revealed sensory neuropathy. The diagnosis of GBS was made based on the Brighton criteria. Patient responded well to intravenous immunoglobulin (IVIG).

DISCUSSION:
GBS is the commonest cause of acute, severe flaccid paralysis globally and the diagnosis remains based on the clinical presentation and ancillary CSF and NCS findings (1). In classical GBS, flaccid weakness involve bilateral extremities in an ascending pattern with reduced or absent deep tendon reflexes, and there may be presence of additional clinical features such as mild sensory symptoms or signs, cranial nerve involvement, autonomic dysfunction, albumin-cytologic dissociation on CSF analysis and electrophysiological evidence of neuropathy(1). Till January 2022, Malaysia had recorded 2.7-million confirmed SARS-CoV-2 cases with an overall fatality rate of approximately 1.1% (5). Neurological sequelae of SARS-CoV-2 include headache, anosmia and dysgeusia to serious events such as stroke, meningoencephalitis and GBS (6). In particular, GBS was reported in 73 patients with preceding SARS-CoV-2 infection, and most of them developed GBS manifestation within 2 weeks from disease onset (7). SARS-CoV-2 associated GBS is likely triggered by an aberrant autoimmunity against the ganglioside components of the peripheral nerves, which then affects various antigens in the axonal subtypes of GBS, resulting in peripheral axon or myeline nerve damage (6). This mechanism is coined as humoral molecular mimicry and has been proven in various infection caused by bacterial and viral pathogens, commonly Campylobacter jejuni sp., Haemophilus influenzae sp., Influenza virus and Epstein- Barr virus (6). Similar to SARS-CoV-2 infection, SARS-CoV-2 vaccination related GBS has been reported. The first global SARS-CoV-2 vaccination programme was initiated in December 2020 as a response to SARS-CoV-2 pandemic with Malaysia began its vaccination programme in February 2021. As of January 2022, Malaysia has vaccinated approximately 80% of its total population and nearly 30% of them has received a third or booster dose [5]. SARS-CoV-2 vaccines demonstrate an efficacy of at least 90% against symptomatic disease in different clinical trials participated by several countries (8). While the potential link between immunisation against SARS-CoV-2 and GBS has not yet been fully proven, it is postulated that SARS- CoV-2 vaccines trigger antibody cross-reaction when the vector containing DNA encoding the S glycoprotein/ spike proteins of SARS-CoV-2 bind to sialic acid-containing gangliosides on cell surfaces (9). According to a recent systematic review of 39 SARS- CoV-2 vaccination associated GBS cases, the commonest clinical GBS variants is the classic form, reported in more than half of cases, followed by bilateral facial palsy with paraesthesia (~30%), paraparetic form (~10%) and GBS- Miller Fisher syndrome overlap variant (<1%) (10). On the other hand, AIDP is the commonest electrophysiological features of SARS-CoV-2 vaccination associated GBS (10). The clinical presentation of our patient with ascending bilateral lower extremities weakness without the involvement of upper extremities would suggest the paraparetic GBS spectrum. The NCS findings of our patient was equivocal and did not fulfil a specific subtype of GBS. Previous cohort study of patient with GBS who underwent NCS (n=440) also reported a forty-two percent of normal or equivocal NCS (11). The clinical features of our patient remained the hallmark of the diagnosis of GBS. Majority of patients recovered with or without neurological deficits after treatment with intravenous immunoglobulin or plasmapheresis with approximately one-fifth required mechanical ventilation during hospitalisation after the diagnosis of SARS-CoV-2 vaccination associated GBS (10). Early recognition and subsequent treatment of GBS could have prevented the rapid progression of the disease course and our patient was discharged and able to ambulate again after received treatment with IVIG. There is still no clear evidence on temporal association between SARS-CoV-2 vaccination and GBS. To the best of our knowledge, this is the first published case report of SARS-CoV-2 vaccine associated GBS in Malaysia and does not imply any causation. Clinicians should remain vigilant and consider GBS in the differential diagnosis of patient who presents with rapidly progressive, symmetric weakness of extremities with reduced or absent deep tendon reflexes, with or without sensory deficits post SARS-CoV-2 vaccination. The benefits of SARS-CoV-2 vaccination far outweigh the risks and this case report should not be seen as a deterrent to the public to receive the vaccination.