53
Poročilo o primeru / Case reportPoročilo o primeru / Case report
ACTA MEDICO–BIOTECHNICA
2023; 16 (1): 53-56
Članek prispel / Received
27. 7. 2022
Članek sprejet / Accepted
14. 4. 2023
Abstract
Purpose: Polyneuritis cranialis 
(PNC) is a less known regional variant 
of Guillain-Barré syndrome and has 
rarely been described in children. Here, 
we report a case of an adolescent, who 
became perilously ill following severe 
acute respiratory syndrome-coronavirus 
2 infection. 
Case report: A 15-year-old boy pre-
sented with acute multiple cranial 
nerve palsies. The presence of GQ1b 
antibodies and nerve conduction studies 
confirmed the diagnosis of PNC. The 
patient was treated with plasmaphere-
sis and intravenous immunoglobulins, 
but clinical improvement was gradual 
and very slow.
Conclusion: PNC is a rare and severe 
neurologic condition that can be trigge-
red by coronavirus infection.
Izvleček
Namen: Kranialni polinevritis je 
manj znana oblika iz skupine Guilla-
in-Barréjevega sindroma in je zelo redko 
opisovan pri otrocih. V prispevku želimo 
opisati primer mladostnika, ki je zbolel 
po okužbi s SARS-CoV-2.
Poro~ilo o primeru: 15-letni fant je 
bil obravnavan zaradi hkratne paralize 
več možganskih živcev. Diagnozo smo 
potrdili z dokazom protiteles GQ1b in 
nevrofizioloških preiskav. Bolnika smo 
zdravili s plazmaferezo in intravenskimi 
imunoglobulini, njegovo klinično stanje 
pa se je izboljševalo zelo počasi in pos-
topoma. 
Zaklju~ek: Kranialni polinevritis je 
redko in hudo nevrološko obolenje, ki ga 
lahko sproži tudi covid-19.
Ključne besede:  
kranialni polinevritis, Miller-Fisherjev 
sindrom, okvare več možganskih 
živcev, covid-19
Key words: 
Polyneuritis cranialis, Miller Fisher 
syndrome, Multiple cranial nerve 
palsy, Coronavirus disease
Kranialni polinevritis, povezan z okužbo s 
SARS-CoV-2: prikaz primera
Polyneuritis cranialis related to SARS-
CoV-2 infection: a case report
Avtor / Author Peter Gradišnik1, Andreja Osterc Koprivšek1, Miha Rus2, Tanja Golli3, 
Hermina Damjan4
Ustanova / Institute 1Univerzitetni klinični center Maribor, Klinika za pediatrijo, Maribor, Slovenija; 2Univerzitetni 
klinični center Maribor, Enota za intenzivno nego in terapijo, Maribor, Slovenija; 3Univerzitetni 
klinični center Ljubljana, Ljubljana, Slovenija; 4Univerzitetni rehabilitacijski inštitut Soča, 
Ljubljana, Slovenija;
1University Medical Center Maribor, Department of Pediatrics, Maribor, Slovenia; 2University 
Clinical Center Maribor, Pediatric Intensive Care Unit, Maribor, Slovenia; 3University Medical 
Centre Ljubljana, University Children's Hospital, Department of Pediatric Neurology, 
Ljubljana, Slovenia; 4University Rehabilitation Institute, Ljubljana, Slovenia;
Naslov za dopisovanje /  
Correspondence
peter.gradisnik@ukc-mb.si
https://doi.org/10.18690/actabiomed.251, CC BY 4.0
© 2023 Avtor(ji) / The Author(s)
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Poročilo o primeru / Case reportPoročilo o primeru / Case report
INTRODUCTION
Polyneuritis cranialis (PNC) represents a variant of Miller-
Fisher syndrome (MFS), which is a form of Guillain-Barré 
syndrome (GBS), an acute immune-mediated peripheral 
neuropathy. The descriptive term “oculopharyngeal 
variant of GBS” has been proposed and partly adopted as 
an alternative name for PNC, an acute immune-mediated 
peripheral neuropathy (1,2). There is a significant 
overlap of MFS variants within the spectrum of GBS 
and significant differences among clinical descriptions 
of PNC reported by patients. Although the number and 
severity of involved cranial nerves can considerably vary, 
cranial nerves I and II are typically spared. Increased titers 
of anti-ganglioside GQ1b antibodies (Abs) are found in 
more than 90% of MFS cases and often present in those 
with the PNC variant (2). 
CASE PRESENTATION
A 15-year-old boy with no previous history of neurologic 
or other chronic disease presented with a short episode of 
fatigue and signs of mild respiratory infection. Two weeks 
later, his voice deepened and became hoarse. Over the 
next 3 days, the patient reported episodes of diplopia and 
dysphagia, which in deteriorated over a period of 2 days to 
complete piecemeal deglutition accompanied by progressive 
dysarthria and, ultimately, aphonia. 
On admission, he was afebrile, alert, and orientated, 
but could only communicate through gesticulations and 
written messages, and exhibited slight asymmetrical facial 
diplegia, which was complete on the left and very obvious 
on the right. The patient was also unable to move the 
right corner of his mouth, but could partially lower his 
right upper eyelid, or protrude his tongue, while lateral 
tongue movements were markedly reduced. No gag reflex 
could be elicited and sialorrhea was observed. The strength 
of the trapezius muscle was normal, while that of the 
sternocleidomastoid muscle was reduced. Bilateral inability 
to turn the eye outwards resulted in convergent strabismus 
and disturbing diplopia. Function of cranial nerves 2–5 and 
8 was normal. The patient also exhibited signs of anosmia, 
dysgeusia, and ataxia. Finger-to-nose and heel-to-shin testing 
showed no limb ataxia or dysmetria. The tendon reflexes 
were clearly present in the lower limbs, but absent in the 
upper limbs. Accordingly, muscular strength was normal in 
the legs, but diminished in the arms and hands, especially 
on the left. Peristalsis was diminished. Other neurologic 
indices were normal.
All conventional blood chemistry parameters were normal. 
Testing of nasopharyngeal swabs for SARS-CoV-2 was 
negative by polymerase chain reaction analysis, but positive 
for Abs against SARS-CoV-2. Magnetic resonance imaging 
(MRI) of the brain revealed no abnormalities. Initial analysis 
of the cerebrospinal fluid (CSF) was normal (protein, 300 
mg/L; 1 cell; immunoglobulin G index, 0.5; negative for 
oligoclonal bands). Malignancies, tuberculosis, sarcoidosis, 
borreliosis, and granulomatosis with polyangiitis were 
excluded, as were botulism and myasthenia gravis. Contrast-
enhanced MRI of the brain showed no abnormalities. 
Due to signs of dysphagia, parenteral nutrition was started. 
Exclusion of other possible causes of multiple cranial 
neuropathies strengthened our suspicion of PNC. We 
confirmed the presence of immunoglobulin G Abs against 
GQ1b ganglioside yet later, but we initiated the polyvalent 
intravenous immunoglobulins (IVIG) administration on 
hospitalization day 3. Testing for other ganglioside Ab types 
was negative.
The patient’s condition deteriorated on hospitalization 
day 4 due to the development of fever, dyspnea, and 
hypoxemia. Serum levels of C-reactive protein increased 
from normal to 237 mg/L. A second lumbar puncture 
showed slight pleocytosis (protein, 380 mg/L, 11 cells). 
An X-ray revealed extensive aspiration pneumonia in the 
right lung. Hence, the patient was sedated and intubated 
for mechanical ventilation. In addition, five courses of 
membrane plasmapheresis every 2 days were  started. 
On day 4 of antibiotic treatment, the patient was afebrile 
again and all markers of inflammation had gradually 
normalized.  Extubation was attempted, but unsuccessful 
despite sufficient respiratory muscle strength. Maintaining 
an open airway could not be sustained due to hypotonia 
of the oropharyngeal muscles and the inability to swallow 
saliva. After a few hours, the patient was sedated and re-
intubated. Artificial ventilation was continued for 2 weeks. 
Termination of artificial ventilation by classical surgical 
tracheostomy improved airway aspiration.
For the first 3 weeks, only parenteral nutrition was possible. 
Peristalsis was weak and had to be stimulated by laxatives 
and metoclopramide. Neostigmine was not administered 
to avoid enhanced salivation. Later, the patient was fed 
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Poročilo o primeru / Case reportPoročilo o primeru / Case report
through a nasogastric tube. Apart from the days requiring 
deep sedation, his consciousness remained intact and he 
was able to communicate through writing. The patient 
consented to tracheostomy, but not gastrostomy for removal 
of the nasogastric tube. His motor function declined due 
to muscular wasting.
The patient was transferred to a tertiary rehabilitation 
center 6 weeks after appearance of the initial symptoms, 
where feeding with a nasogastric tube and tracheostomy 
were continued. Because the clinical symptoms improved 
very slowly, he was referred to our tertiary Pediatric 
Neurology Department at 8.5 weeks after admission for 
further evaluation. Follow-up contrast-enhanced MRI 
of the brain and cervical spinal cord was normal and 
testing for neurodegenerative diseases was negative. Nerve 
conduction studies (NCSs) and electromyography (EMG) 
were conducted at 9 weeks after admission. NCSs of the 
upper and lower limbs were normal, except for prolonged 
F response latencies, low F response persistence, and signs 
of chronodispersion in several nerves of the upper and 
lower limbs. NCSs of the facial nerves showed very low 
amplitude compound muscle action potential responses in 
all branches and markedly prolonged distal latency of one of 
the six tested facial nerve branches, changes consistent with 
predominant axonal damage and possible demyelination. 
Needle EMG changes were consistent with a subacute 
neuropathic process.
Two addition courses of IVIG at 4-week intervals were 
administered at the rehabilitation center and symptoms 
steadily, but slowly, improved. The patient’s ability to 
taste and smell returned at about 8 weeks after the initial 
symptoms. IVIG was discontinued after the four courses  
(12 weeks after admission), as the clinical manifestations 
continued to improve. The patient’s ability to swallow was 
sufficient at 13 weeks to start partial peroral feeding with 
dense liquids. The tracheal cannula was removed shortly 
afterward.  After decannulation, the patient’s voice was very 
weak and his speech dysarthric, but gradually improved 
to near normal. While the tracheostomy wound healed, 
he used special maneuvers to communicate. Discrete 
facial asymmetry and slight facial muscle weakness, more 
pronounced on the left side, were still obvious at 18 
weeks, but disappeared at 23 weeks. Muscular strength 
was eventually restored, allowing the patient to walk without 
problems, while functioning of his arms and hands had 
returned to normal. The nasogastric tube was removed 
once normal eating was possible and diplopia had subsided 
at 23 weeks. 
Figure 1: The patient at 6 weeks after admission. 
Note convergent strabismus, facial diplegia, and inabil-
ity to swallow. A cuffed tracheostomy tube was used to 
prevent further problems with aspiration.
DISCUSSION
Our patient exhibited rapid progression of slightly 
asymmetrical cranial nerve palsies after an upper respiratory 
tract infection. Despite early and aggressive treatment, there 
was no immediate improvement. Most patients with PNC 
recover and are discharged from the hospital in about 11 
weeks (2). A fast and full recovery was reported in a case of 
a 10-year-old boy with PNC after just two courses of IVIG 
(3). Because PNC was not the only differential diagnosis 
in this case, diagnosis was extended to other possible 
causes. Multiple cranial neuropathies can occur with 
several infectious, inflammatory, or neoplastic lesions of 
the skull base or brainstem (4). Systemic diseases, including 
diabetes mellitus, have also been linked to PNC. However, 
laboratory tests and neuroimaging excluded these causes in 
this patient. Myasthenia gravis, which was ruled-out, can 
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Poročilo o primeru / Case reportPoročilo o primeru / Case report
also initially present with involvement of multiple cranial 
nerves. Albuminocytological dissociation is common with 
GBS, but only 67% of reported PNC cases (2). Analysis of 
the first lumbar puncture of this patient was completely 
normal, while the second showed slight pleocytosis, 
although no elevated protein levels in the CSF, which is 
less common but does not exclude a diagnosis of PNC (4). 
An antecedent respiratory infection is common with PNC, 
as demonstrated with our patient, who exhibited a complete 
loss of smell, which was attributed as a consequence of 
SARS-CoV-2 infection, rather than a sign of the involvement 
of the first cranial nerve in PNC. Involvement of the upper 
limbs might represent an overlap to the pharyngeal-cervical-
brachial form of GBS, which often involves the presence 
of anti-GT1a Abs. However, this patient was negative for 
anti-GT1a Abs. Limb weakness is uncommon in patients 
with oculopharyngeal involvement and is more suggestive 
of MFS. Our patient, however, showed no signs of ataxia 
and deep tendon reflexes were preserved in the lower limbs.
Although the nasopharyngeal swabs were negative, the lack 
of relevant medical history, presence of anti-GT1a Abs, 
and loss of taste and smell supported the presumption 
that SARS-CoV-2 triggered PNC in this patient. Several 
cases of MFS have been reported as an adverse effect of 
vaccines against COVID-19 (5). However, our patient 
was not vaccinated. Common neurologic complications 
among adults hospitalized for COVID-19 include myalgia, 
headache, encephalopathy, dizziness, dysgeusia, and 
anosmia (6). Stroke, movement disorders, motor and 
sensory deficits, ataxia, and seizures have been described, 
but are less common. Neurologic deficits can arise both 
from the direct effects of the virus as well as systemic 
responses to infection. Anosmia is considered to be a direct 
consequence of olfactory bulb injury (7). Among immune-
mediated complications, several cases of GBS have been 
described in patients with COVID-19, but only one case 
of PNC in an adult (8). 
CONCLUSION
Autoimmune response-related complications of 
COVID-19 might be the most serious. PNC is a rare 
neurologic condition that can be triggered by COVID-19 
and affects children most gravely. Vaccination of the 
pediatric population not only helps to prevent spread of 
the virus, but also prevents serious complications, which 
are also possible in children. 
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