Wernicke’s Encephalopathy in Setting of Hyperemesis Gravidarum and Unexpected Pregnancy! 4/4/2019

Credit goes to Dr. Jon Reitzenstein from Michigan State!

Today we went over a case featured on the Human Diagnosis Project.

A 28yo F with no medical history presents with 1 day history of unsteady gait, with associated “indifference” per her husband and intermittent diplopia. She also has been having significant N/V for the past 3-4 weeks, barely able to keep anything down. She was dehydrated on exam with elevated spec grav and ketones on the UA. Her pregnancy test returned positive (estimated 6 week old fetus). Ultimately she was given thiamine with rapid symptomatic improvement.

The final diagnosis is Wernicke’s Encephalopathy in setting of poor nutritional intake and increased metabolic demands secondary to unexpected/unknown pregnancy.


Wernicke’s Encephalopathy

Epidemiology

  • Most cases are associated with chronic EtOH use but not all the time!
  • Non-alcohol related:
    • Hyperemesis gravidarum
    • Bariatric surgery
    • Long-term TPN
    • HIV
    • Malignancies
    • Extreme poverty, war zones, refugees
  • More common in men
  • Up to 12.5% of pts with chronic EtOH

Pathophysiology

  • Chronic inadequate intake of thiamine (vitamin B1) leading to degeneration of the peripheral nerves, thalamus, mammillary bodies, and cerebellum.

Presentation: triad of

  • Encephalopathy (disorientation, inattentiveness, indifference)
  • Gait ataxia
  • Oculomotor symptoms (nystagmus, lateral rectus palsy, conjugate gaze palsies)
  • Triad only seen in 1/3 of patients, most only have around 2.
  • Other signs: Memory impairment, hypothermia, electrolyte derangements often related to dietary, withdrawal if related to alcohol

Diagnosis: Clinical but there is a proposed Caine Criteria, 2/4 of these meet Caine Criteria for Wernicke encephalopathy. Sensitivity up to 85%

  • Dietary deficiency
  • Oculomotor abnrl
  • Cerebellar dysfunction
  • Encephalopathy or memory impairment.
  • Serum thiamine is rarely tested and takes a while to come back, so when in doubt, start thiamine and don’t wait for levels.
  • MRI might show hyperintensities around the periaqueductal white matter and thalami

Management

  • Always give thiamine first and NOT glucose.
    • Thiamine must be repleted first or else glucose infusions may worsen symptoms.
    • Alcoholics should receive IV thiamine, at least 100mg, before receiving any IV glucose solutions.
  • Thiamine:
    • 500mg IV TID x 3 days, then 250mg IV daily for 3-5 days, then transition to 100mg PO daily.

Prognosis

  • Prompt thiamine treatment leads to improvement in ocular sx within hours to days.
  • Vestibular/gait improves within weeks.
  • 60% will have residual ocular symptoms and gait abnormalities. Up to 80% of patients might have residual memory deficits.

Korsakoff Syndrome: Irreversible. Memory loss (selective anterograde or retrograde amnesia), confabulation, +/- hallucinations

Hyperemesis Gravidarum

Presentation

  • Uncontrollable vomiting during pregnancy that results in dehydration, weight loss, and ketosis.
  • Usually begins at about 5 weeks of gestation, peaks at 9 weeks, and resolves by 16-18.
  • While vomiting in pregnancy (esp in the morning) is common, HG is an extreme form.

Diagnosis: Clinical, laboratory abnormalities

Management: Supportive, antiemetics

  • Doxylamine + Vit B6
  • Promethazine (Phenergan)
  • Metoclopramide (Reglan)
  • Ondansetron (Zofran)
  • Prochlorperazine
  • Corticosteroids (methylprednisolone) can be trialed if initial treatment is ineffective. Generally avoided prior to 6 weeks of gestation (organogenesis)