When can deep tendon reflexes be expected to recover in patients with Guillain‑Barré syndrome?

Recovery of Deep Tendon Reflexes in Guillain-Barré Syndrome

Deep tendon reflexes in GBS patients are typically decreased or absent at presentation and nadir, but recovery patterns are highly variable and can extend beyond 3 years after disease onset, with some patients never fully regaining reflexes while others—particularly those with the AMAN subtype and anti-GM1 antibodies—may paradoxically develop hyperreflexia during early recovery. 1

Expected Timeline and Recovery Patterns

The recovery of deep tendon reflexes (DTRs) in GBS does not follow a predictable, uniform timeline. According to the 2019 Nature Reviews Neurology guideline, recovery can continue for more than 3 years after disease onset, and this applies to all neurological functions including reflexes 1. Most extensive recovery occurs within the first year, with approximately 80% of patients regaining independent walking ability by 6 months 1.

Key Clinical Patterns:

Classic Presentation:

• Reflexes are decreased or absent in most patients at presentation
• Almost all patients show areflexia at nadir (maximum disability) 1
• Recovery of reflexes typically parallels overall neurological recovery
• Some patients may have persistent areflexia despite functional motor recovery

Atypical Patterns with Preserved or Exaggerated Reflexes:

A critical caveat that clinicians must recognize: approximately 10% of GBS patients maintain normal or even exaggerated reflexes throughout their entire disease course 1. This occurs particularly in:

• Pure motor variant with AMAN subtype (acute motor axonal neuropathy) on electrophysiology 1
• Patients with anti-GM1, GM1b, GD1a, or GalNAc-GD1a antibodies (present in 74-89% of DTR-preserved cases) 2, 3, 4
• Those with milder disease severity 3

Hyperreflexia as a Recovery Sign

In 13% of patients—especially those with AMAN and anti-GM1 antibodies—hyperreflexia develops during the early recovery phase (typically within the first few weeks after nadir) 3. This represents increased motor neuron excitability and is actually associated with:

• Milder peak disability 3
• More rapid clinical recovery (improvement by ≥2 Hughes grades within 2 weeks in some cases) 4
• Better overall prognosis 4

One case report documented reflexes beginning to improve 2-3 days following IVIG treatment 5, though this represents an unusually rapid response.

Clinical Implications and Pitfalls

Common Pitfall: Do not exclude GBS based solely on preserved reflexes. The presence of normal or hyperactive DTRs does not rule out GBS, particularly in patients with:

• Pure motor weakness without sensory signs (87% of DTR-preserved cases) 2
• Ability to walk 5 meters independently at nadir (70% of DTR-preserved cases) 2
• Preceding Campylobacter jejuni or Haemophilus influenzae infection 2, 4

Diagnostic Approach: When evaluating reflex recovery, consider:

• Serial examinations over weeks to months
• Electrophysiological subtype (AMAN vs AIDP)
• Anti-ganglioside antibody testing if available
• Overall functional recovery trajectory using mEGOS scoring 1

Long-term Expectations

Recovery of reflexes may still occur beyond 5 years after disease onset 1, though most improvement happens earlier. Patients should be counseled that:

• Persistent areflexia does not necessarily correlate with functional disability
• Some patients achieve excellent functional recovery despite absent reflexes
• Conversely, reflex recovery does not guarantee complete resolution of other symptoms (fatigue, pain, weakness) 1

The absence of reflex recovery should not be used as the sole prognostic indicator, as overall functional outcomes depend on multiple factors including age, disease severity at nadir, and response to immunotherapy 1.