Peripheral Polyneuropathies (including Guillain-Barré)

The most common manifestation of this is a Distal Symmetrical Polyneuropathy (DSPN), which is:

• Length-dependent

• In a “Glove and Stocking” distribution – Feet and distal legs first, hands later

Causes - CRAIG DAVID MC:

• Cancer

• Renal

• Amyloid

• Infection (HIV, Lyme)

• Guillain-Barre Syndrome

• Diabetes

• Alcohol

• Vit deficiencies (B12/Folate)

• Inherited (Charcot-Marie Tooth)

• Drugs (Chemo, HIV drugs)

• Metabolic (Hypothyroidism), Metals (Lead)

• Critical care

Guillain-Barre Syndrome (GBS)

This is an acute, symmetrical, ascending weakness +/- sensory symptoms that typically occurs 1-3 weeks post-infection, particularly due to campylobacter jejuni, cmv or ebv infections. In the process, there are cross-reactive antibodies produced by plasma cells, leading to an immune-mediated demyelination of different neurons (Molecular mimicry). The 3 types of it are:

• AIDP – Acute Inflammatory Demyelinating Polyradiculoneuropathy – Mixed GBS

• AMAN – Acute Motor Axonal Neuropathy – Pure Motor GBS

• AMSAN – Acute Motor Sensory Axonal Neuropathy – Pure Sensory GBS

Prognosis:

• 80% fully recover

• 15% left with some neurological deficit

• 5% die

Presentation

• Pain

• Symmetrical weakness, starting distally in lower limbs, and ascending proximally (Paresthesia may occur in the same pattern)

• Facial weakness

• LMN signs in lower limbs – Hypotonia, Areflexia, Flaccid paralysis

• Autonomic involvement – Cardiac, Bladder, Bowel

Can eventually ascend and lead to respiratory muscle involvement, which presents as T2 respiratory failure (i.e. hypoxic CO2 retention). These patients require ventilatory support.

Investigations

• LP – Raised protein w/normal cell count and glucose

• Vital capacity (VC) - Monitor and check for any respiratory involvement

• ABG – Check for T2 RF

• ECG - Cardiac monitoring

• NCS – Reduced signals – Shouldn’t be delayed

• HIV test

Management

IVIG (IV Immunoglobulins) or PLEX (Plasma Exchange)