28. Toxic/Metabolic and Nutrition Related Neurological Disorders

What are the three key symptoms of B1 deficiency?

Confusion, ocular abnormalities, and ataxia

What are the ocular abnormalities seen in B1 deficiency?

Nystagmus and ophthalmoplegia

What is the cause of ophthalmoplegia in B1 deficiency?

Difficulty moving the eyes

What are major risk factors for B1 deficiency?

Malnutrition, GI surgeries, hyperemesis gravidarum, alcohol use disorder

What must be given before glucose in suspected B1 deficiency?

IV thiamine

Why must thiamine be given before glucose?

To prevent worsening of B1 deficiency

What is a key symptom of central pontine myelinolysis?

Progressive weakness in all limbs

When does weakness occur in central pontine myelinolysis?

Days after over-rapid correction of chronic hyponatremia

What are risk factors for chronic hyponatremia?

Certain medications, poor nutrition, alcohol use disorder

What causes central pontine myelinolysis?

Over-rapid correction of chronic hyponatremia

What is the prevention strategy for central pontine myelinolysis?

Gradual correction of chronic hyponatremia

What is the sodium correction goal to prevent CPM?

No more than 8 mEq/L/day

What is the key symptom of botulinum toxin exposure?

Progressive flaccid paralysis

What reflex finding is seen in botulism?

Areflexia

Which muscles are affected in botulism?

Bulbar and limb muscles

What is preserved in botulism?

Sensation

What organism produces botulinum toxin?

Clostridium botulinum (gram-positive anaerobic rod)

What does botulinum toxin block?

Acetylcholine release at the neuromuscular junction

What is a risk factor for infant botulism?

Ingesting honey containing bacterial spores

How is foodborne botulism contracted?

Eating food contaminated with C. botulinum spores

What is the treatment for botulism?

Remove exposure and provide respiratory support

What is the hallmark symptom of tetanus?

Lockjaw (trismus)

What muscle symptoms are seen in tetanus?

Progressive stiffness and spasms

Which reflexes are increased in tetanus?

Deep tendon reflexes

What happens to muscle tone in tetanus?

Increased tone

What organism produces tetanus toxin?

Clostridium tetani (gram-positive anaerobic rod)

What does tetanus toxin block?

Glycine and GABA release

What is a classic tetanus exposure scenario?

Rusty nail wound in an unimmunized individual

What are treatments for tetanus?

Remove exposure, give tetanus immunoglobulin, muscle relaxants, and respiratory support

What is the main physiologic effect of anticholinesterase toxicity?

Parasympathetic overactivation

What mnemonic is used to remember symptoms of anticholinesterase poisoning?

DUMBBELLS

What are common sources of anticholinesterase exposure?

Organophosphate pesticides and other cholinesterase inhibitors

What is the treatment for anticholinesterase poisoning?

Remove exposure and give antimuscarinics like atropine

What part of the spinal cord is affected by B12 deficiency?

Dorsal columns and corticospinal tracts

What sensory symptom is seen in B12 deficiency?

Vibration sense loss

What motor signs occur in B12 deficiency?

Spasticity and hyperreflexia

What are risk factors for B12 deficiency?

Malnutrition, GI surgeries, alcohol use disorder, vegan diet, atrophic gastritis

What is the treatment for B12 deficiency?

B12 repletion (oral or IM depending on cause)

What is a hallmark feature of delirium?

Fluctuating attention

What are common causes of delirium?

Metabolic abnormalities, medication side effects

What is a major risk factor for delirium?

Underlying dementia

What is the treatment approach for delirium?

Supportive care and minimizing risk factors