Miller Fisher Syndrome: A variant of Guillain Barre Syndrome characterized by the triad of ophthalmoplegia, ataxia, and areflexia, making it a close differential diagnosis due to overlapping symptoms.

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): Similar to Guillain Barre Syndrome but with a more chronic course, making it a consideration in patients with prolonged or recurrent symptoms.
Myasthenia Gravis: An autoimmune disorder affecting the neuromuscular junction, which can present with fluctuating muscle weakness, potentially mimicking the weakness seen in Guillain Barre Syndrome.
Botulism: A neurotoxic disorder that can cause descending paralysis, which might be confused with the ascending paralysis of Guillain Barre Syndrome, especially in the early stages.
Poliomyelitis: Although rare in areas with good vaccination coverage, polio can cause acute flaccid paralysis similar to Guillain Barre Syndrome.

Spinal Cord Compression: A condition that requires urgent intervention, as it can cause rapid progression of neurological deficits, including paralysis, and can be mistaken for Guillain Barre Syndrome if not promptly diagnosed.
Porphyric Neuropathy: A rare condition that can mimic Guillain Barre Syndrome but is associated with abdominal pain, psychiatric symptoms, and sometimes skin sensitivity, and requires specific treatment.
Diphtheritic Neuropathy: Caused by the diphtheria toxin, it can lead to neurological symptoms similar to Guillain Barre Syndrome, emphasizing the importance of vaccination and considering this diagnosis in unvaccinated individuals.
Tick Paralysis: A condition caused by a neurotoxin in the saliva of certain ticks, leading to ascending paralysis that can be indistinguishable from Guillain Barre Syndrome without a thorough history and examination.

Neuropathy due to Vitamin Deficiencies (e.g., Vitamin B12 deficiency): While not typically presenting with the acute onset of Guillain Barre Syndrome, severe deficiencies can cause neurological symptoms, including weakness and neuropathy.
Heavy Metal Poisoning (e.g., Lead, Arsenic): Certain heavy metals can cause neuropathy, which might be considered in the differential diagnosis, especially with a suggestive exposure history.
Sarcoidosis: A systemic disease that can affect the nervous system, causing neuropathy among other symptoms, and could be considered in patients with other systemic symptoms suggestive of sarcoidosis.
Lyme Disease: Neurological manifestations of Lyme disease, such as Lyme meningitis or radiculoneuritis, can occasionally be confused with Guillain Barre Syndrome, particularly in endemic areas.