The confused binge drinker

Diagnosis. Making the correct diagnosis is challenging because the clinical presentation can be variable. No lab or imaging studies confirm the diagnosis. The triad of signs considered to support the diagnosis include ocular signs such as nystagmus, cerebellar signs, and confusion. These signs occur in only 8% to 10% of patients in whom the diagnosis likely.^1,2

Attempts to increase the likelihood of making an accurate lifetime diagnosis of
Wernicke’s encephalopathy include expanding the focus to 8 clinical domains:
• dietary deficiency
• eye signs
• cerebellar signs
• seizures
• frontal lobe dysfunction
• amnesia
• mild memory impairment
• altered mental status.¹

The sensitivity of making a correct diagnosis increases to 85% if at least 2 of 4 features—namely dietary deficiency, eye signs, cerebellar signs, memory impairment, and altered mental status—are present. These criteria can be applied to alcoholic and nonalcoholic patients.¹Table 2_³ lists common and uncommon symptoms of Wernicke’s encephalopathy.

Although CT scan of the brain is not a reliable test for the disorder, MRI can be powerful tool that could support a diagnosis of acute Wernicke’s encephalopathy.¹ We did not consider MRI in Mr. P’s case because the consulting neurologist thought this was unnecessary because of the quick improvement in his cognitive status with IV thiamine—although MRI might have helped to detect the disease earlier. In some studies, brain MRI revealed lesions in two-thirds of Wernicke’s encephalopathy patients.¹ Typically, lesions are symmetrical and seen in the thalamus, mammillary body, and periaqueductal areas.^1,4 Atypical lesions commonly are seen in the cerebellum, dentate nuclei, caudate nucleus, and cerebral cortex.¹

Treatment. Evidence supports use of IV thiamine, 200 mg 3 times a day, when the disease is suspected or established.^1,2 Thiamine has been associated with sporadic anaphylactic reactions, and should be administered when resuscitation facilities are available. Do not delay treatment because resuscitation measures are unavailable because you risk causing irreversible brain damage.¹

In Mr. P’s case, prompt recognition of the need for thiamine likely led to a better outcome. Thiamine supplementation can prevent Wernicke’s encephalopathy in some patients. Prophylactic parenteral administration of thiamine before administration of glucose in the ED is recommended, as well as vitamin B supplementation with thiamine included upon discharge.^1,2 Studies support several treatment regimens for patients with Wernicke’s encephalopathy and those at risk of it.^1,3,5

Neither the optimal dosage of thiamine nor the appropriate duration of treatment have been determined by randomized, double-blind, controlled studies; empirical clinical practice and recommendations by Royal College of Physicians, London, suggest that a more prolonged course of thiamine—administered as long as improvement continues—might be beneficial.⁶

Left untreated, Wernicke’s encephalopathy can lead to irreversible brain damage.²
Mortality has been reported as 17% to 20%; 82% of patients develop Korsakoff’s syndrome, a chronic condition characterized by short-term memory loss. One-quarter of patients who develop Korsakoff’s syndrome require long-term residential care because of permanent brain damage.²

Making a diagnosis of Wernicke’s encephalopathy is a challenge because no specific symptom or diagnostic test can be relied upon to confirm the diagnosis. Also, patients might deny that they have an alcohol problem or give an inaccurate history of their alcohol use,² as Mr. P did. The disorder is substantially underdiagnosed; as a consequence, patients are at risk of brain damage.²

Bottom Line

Not all patients who present with aggressive behavior, mania, and psychiatric
symptoms have a primary psychiatric diagnosis. It is important to consider
nutritional deficiencies caused by chronic alcohol abuse in patients presenting
with acute onset of confusion or altered mental status. Wernicke’s encephalopathy
might be the result of alcohol abuse and can be treated with IV thiamine.

Disclosure
The authors report no financial relationships with any company whose products are mentioned in this article or with manufacturers of competing products.