Pharyngeal–Cervical–Brachial Variant of Guillain–Barré Syndrome: A Clinical Case Report

Abstract

Guillain-Barré syndrome (GBS) is an acute, immune-mediated polyradiculoneuropathy with several atypical variants. The pharyngeal-cervical-brachial (PCB) variant is a rare subtype characterized by rapidly progressive weakness of the oropharyngeal, neck, and upper limb muscles, often with relative sparing of the lower limbs. We present a patient who developed progressive upper-limb weakness and neck involvement without significant lower-limb deficit, clinically consistent with the PCB variant of GBS. Daily neurological assessments showed no improvement until the 3^rd day of admission, after which evolving findings of upper-limb hypotonia, absent reflexes, and preserved lower-limb power were observed. Serial monitoring of respiratory effort using single breath count remained satisfactory, ruling out early respiratory compromise. This case underscores the diagnostic importance of recognizing PCB-GBS, which may mimic brainstem or cervical spinal pathology and highlights the role of meticulous bedside monitoring and early immunotherapy in improving the outcomes.

INTRODUCTION

Guillain–Barré syndrome (GBS) represents a group of acute, monophasic, immune-mediated neuropathies typically presenting with ascending limb weakness and areflexia. However, atypical regional variants have been increasingly recognized. One such form is the pharyngeal-cervical-brachial (PCB) variant, first described by Wakerley et al in 1986, characterized by rapid paralysis of the oropharyngeal, cervical, and upper limb muscles with minimal or no involvement of the lower limbs.[1]

PCB-GBS is uncommon, accounting for 2%–5% of all GBS cases.[2] It is frequently associated with anti-GT1a and anti-GQ1b antibodies, which mediate immune-driven dysfunction at the nodes of Ranvier in motor fibers.[3] Clinically, PCB presents with dysphagia, neck flexor weakness, and proximal upper-limb weakness and may mimic brainstem stroke, myasthenia gravis, or botulism.[4] Early recognition is critical because treatment with intravenous immunoglobulin (IVIg) or plasmapheresis can substantially modify disease progression and improve prognosis.[5]

Here, we present the case of a patient exhibiting progressive upper-limb weakness, neck stiffness, and preserved lower-limb strength, clinically aligning with the PCB variant of GBS. This report emphasizes the diagnostic significance of detailed daily neurological evaluation and the necessity for clinicians to maintain a high index of suspicion for atypical GBS variants.

CASE REPORT

An 18-year-old male presented with a history of fever with chills for 7 days followed by bilateral upper limb weakness for 5 days, associated with slurring of speech and difficulty in swallowing. There was no nasal regurgitation. The patient also complained of mild neck weakness and difficulty in the changing position. There was no sensory loss, diplopia, or limb pain, and the lower limbs were unaffected.

On admission, vital parameters were stable, and single breath count (SBC) was 31, indicating adequate respiratory effort. Baseline investigations, including complete blood count, serum electrolytes, and renal function tests, were within the normal limits.

Neurological examination on admission (day 1)

• Cranial nerves:

  • Palatal weakness with absent gag reflex, suggestive of 10^th and 12^th cranial nerve involvement

  • Facial nerve examination was performed and wrinkling is absent with not able blow cheeks and close eye tightly with loss of B/L nasolabial fold

  • No ophthalmoplegia or facial asymmetry noted.

• Motor system:

  • Upper limbs: Tone hypotonic, power 2/5 bilaterally

  • Lower limbs: Tone and power (2/5).

• Reflexes:

  • Biceps: Absent bilaterally

  • Triceps: Absent bilaterally

  • Knee: 2+ bilaterally

  • Ankle: 2 + bilaterally

  • Plantar: Flexor bilaterally.

Sensation and coordination were intact.

Central nervous system examination– day 4–5

• The patient showed no worsening of symptoms

• Upper limbs: Power remained 3/5, tone persisted as hypotonia

• Lower limbs: Power and tone remained normal (5/5)

• Reflexes: Upper limb reflexes continued to be absent, lower limb reflexes 2+

• SBC: 30, adequate.

Central nervous system Examination– Day 7

• Marked clinical improvement noted.

• Tone: Normalized in upper limbs.

• Power: 4+/5 in upper limbs, 5/5 in lower limbs.

• Reflexes:

  • Upper limb: Biceps and triceps 1 + bilaterally

  • Knee and ankle: 2+ bilaterally [Table 1]

• Cranial nerves: Improved gag reflex and swallowing ability.

• SBC: 32, stable.

Table 1.

Reflexes

Reflex	Right	Left
Biceps	1+	Absent
Triceps	1+	1+
Knee	2+	2+
Ankle	↓	↓
Plantar	↓	↓

↓ Decreased reflex

Deep-tendon reflexes in the upper limbs were diminished, while those in the lower limbs were preserved. Plantar responses were flexor bilaterally. Sensation and coordination were intact.

Investigations

Nerve conduction studies (NCSs) demonstrated reduced compound muscle action potentials in upper limb motor nerves with preserved sensory responses, consistent with motor demyelinating neuropathy.

Neuroimaging (magnetic resonance imaging [MRI] of the brain and cervical spine and Ultrasonography abdomen): Unremarkable, ruling out structural lesions.

Cerebrospinal fluid (CSF) analysis:

• Appearance: Clear, colorless

• Total leukocyte count: 0–2 cells/mm³ (predominantly lymphocytes)

• Protein: 98–120 mg/dL (elevated)

• Glucose: 62 mg/dL (serum glucose: 98 mg/dL)

• Gram stain/ Acid Fast Bacilli (AFB)/Culture: Negative.

Diagnosis

Based on the NCS suggestive of motor demyelinating polyneuropathy involving all four limbs, possibility of early PCB variant of GBS was established.

DISCUSSION

GBS represents a heterogeneous spectrum of acute, immune-mediated polyneuropathies with variable clinical phenotypes. While the classic form manifests as an ascending areflexic paralysis, regional variants such as the PCB variant may show highly localized weakness and reflex changes confined to the oropharyngeal, neck, and upper limb muscles.[1,2] The PCB variant is rare, accounting for approximately 2%–5% of all GBS cases, but its recognition is clinically significant because early diagnosis enables prompt immunotherapy and reduces morbidity.[3]

The PCB variant, like other GBS subtypes, is believed to result from molecular mimicry between microbial antigens and peripheral nerve gangliosides, leading to autoimmune attack on motor fibers.[4] Campylobacter jejuni, Haemophilus influenzae, and cytomegalovirus have been implicated as antecedent infections.[5] Immunological studies have demonstrated a strong association between the PCB variant and anti-GT1a and anti-GQ1b IgG antibodies, which target gangliosides abundantly expressed at the nodes of Ranvier within lower cranial and cervical motor nerves.[6,7] The binding of these antibodies triggers complement-mediated demyelination and axonal injury, producing rapid paralysis of pharyngeal, cervical, and brachial musculature.[8]

Clinically, patients typically present with acute or subacute weakness involving the oropharyngeal muscles (causing dysphagia, nasal speech, or palatal weakness), neck flexors, and proximal upper limbs, while lower limb power is relatively preserved.[7] Deep-tendon reflexes in the affected limbs are diminished or absent, although lower limb reflexes may remain intact, as observed in our patient. Respiratory failure can occur if diaphragmatic or bulbar muscles become involved, making serial monitoring of SBC a simple but vital bedside tool.[8]

The diagnosis of PCB-GBS is primarily clinical, supported by electrophysiological and serological evidence. NCS often reveal reduced compound muscle action potentials with relatively preserved sensory responses, indicating motor-predominant demyelinating neuropathy.[8]

Differential diagnosis

PCB-GBS can mimic a variety of neurological disorders, particularly brainstem stroke, myasthenia gravis, botulism, and cervical cord lesions.[5] Differentiation relies on a combination of clinical pattern, imaging, and electrophysiology:

• Brainstem stroke typically presents with long-tract signs, sensory deficits, or gaze palsies – absent in this case. MRI was normal, excluding structural lesions

• Myasthenia gravis causes fatigable weakness and fluctuating ptosis, without sensory involvement or CSF abnormalities; edrophonium testing and antibody assays are negative in PCB-GBS

• Botulism presents with pupillary involvement and autonomic dysfunction, which were not seen here

• Cervical myelopathy would produce sensory level and sphincter disturbances, absent in this patient.

Hence, the combination of symmetrical upper limb weakness, areflexia, oropharyngeal involvement, preserved lower limb function, and CSF/NCS findings supports PCB-GBS as the most probable diagnosis.[6,7]

Management and prognosis

The mainstay of treatment for all GBS variants, including PCB, is immunotherapy with IVIg or plasma exchange, both shown to shorten recovery time and improve outcomes.[8] Our patient received standard IVIg therapy (0.4 g/kg/day for 5 days) and demonstrated progressive improvement in swallowing and limb strength within 2 weeks. Early intervention is crucial, as delayed therapy is associated with prolonged mechanical ventilation and residual weakness.[8] Supportive care – particularly respiratory monitoring, prevention of aspiration, and physiotherapy – remains integral to management.

Prognosis in PCB-GBS is generally favorable, with most patients achieving near-complete recovery within 3 months. However, severe cases with early bulbar or respiratory involvement may progress to generalized GBS or require ventilatory support. The presence of anti-GT1a antibodies has been associated with a more limited but protracted course.

Clinical relevance

This case highlights several important clinical lessons. First, PCB-GBS may present insidiously, and the absence of lower limb involvement can mislead clinicians away from considering GBS. Second, daily neurological documentation – including reflexes, tone, and power – enables the detection of evolving deficits before respiratory failure ensues. Third, a normal MRI with characteristic electrophysiological and serological findings should prompt the consideration of an immune-mediated neuropathy rather than central pathology.

Finally, this case reinforces that even in the resource-limited settings, clinical vigilance and timely immunotherapy can yield excellent functional recovery.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.