A woman in her 20s developed Wernicke's encephalopathy—a brain condition caused by thiamine deficiency—after eight weeks of uncontrolled vomiting from cannabinoid hyperemesis syndrome.
Emergency physicians treating CHS, heavy cannabis users experiencing persistent vomiting, and clinicians who associate Wernicke's encephalopathy only with alcoholism.
What the researchers found
This case describes an uncommon but serious cascade: heavy cannabis use triggered cannabinoid hyperemesis syndrome (CHS), which caused weeks of persistent vomiting, which led to severe thiamine (vitamin B1) deficiency, which ultimately caused Wernicke's encephalopathy—a neurological emergency typically associated with alcoholism.
The patient, a woman in her 20s, presented after eight weeks of nausea and vomiting. She had lost more than 10 kg of body weight. Two weeks before admission, she developed double vision, unsteady gait, and confusion—the classic triad of Wernicke's encephalopathy. Brain MRI confirmed the diagnosis, showing the characteristic symmetric thalamic lesions.
The good news: intravenous thiamine produced a rapid and dramatic recovery. The important lesson: Wernicke's encephalopathy is not just an alcoholic's disease. Any condition that causes prolonged vomiting and malnutrition—including CHS—can deplete thiamine stores enough to damage the brain.
CHS itself is well-recognized: cyclic vomiting in heavy cannabis users, typically relieved by hot showers, that resolves when cannabis use stops. But this case shows that the vomiting phase can become dangerous in its own right if it persists long enough to cause nutritional deficiencies.
Why it matters
Most CHS discussions focus on the vomiting itself and the relief from hot showers. This case reveals a downstream risk that clinicians may not anticipate: prolonged CHS vomiting can cause nutritional deficiencies severe enough to produce brain damage. It also highlights that Wernicke's encephalopathy should be on the differential diagnosis for any patient with prolonged vomiting and new neurological symptoms—not just alcoholic patients.
The numbers in context
8 weeks of nausea and vomiting. >10 kg weight loss. Double vision and ataxia developed 2 weeks before admission. Rapid recovery with IV thiamine.
How the study worked
Single case report of a woman in her 20s presenting with Wernicke's encephalopathy secondary to thiamine deficiency caused by prolonged vomiting from cannabinoid hyperemesis syndrome. Diagnosis confirmed by brain MRI showing T2/FLAIR symmetric thalamic hyperintensities.
Who was studied
One woman in her 20s with a history of nausea and vomiting.
What this study cannot tell us
Single case report—cannot establish how common this complication is among CHS patients. No information on the patient's cannabis use patterns (frequency, potency, duration). The dramatic response to thiamine confirms the diagnosis but doesn't tell us whether early supplementation could have prevented the neurological complications.
How to read the evidence
Single case report—the lowest tier of evidence, but valuable for identifying rare complications that wouldn't be captured in larger studies.
When this study was published
Published in 2025, adding to the growing CHS literature.
The bigger picture
CHS has become increasingly recognized as cannabis potency and use frequency have risen (see RTHC-00162 on increasing cannabis-related emergency visits). This case adds a new dimension to the CHS clinical picture—it's not just about managing vomiting and dehydration, but about preventing the nutritional complications that can follow prolonged emesis. The Wernicke's encephalopathy connection also parallels how other chronic conditions (eating disorders, bariatric surgery, hyperemesis gravidarum in pregnancy) can cause thiamine deficiency through the same mechanism.
Replication
Not stated in abstract.
Funding
Not reported in abstract.
Conflicts of interest
Not reported in abstract.
Questions still open
- How often do CHS patients develop clinically significant nutritional deficiencies? Should thiamine supplementation be standard care for CHS patients with prolonged vomiting? Are there other nutritional deficiencies being missed in the CHS population?
Read the original research
Wernicke's Encephalopathy Secondary to Cannabis Hyperemesis Syndrome.
Journal of Brown hospital medicine, 5(1), 151455
The Journal of Brown Hospital Medicine publishes clinical research and case reports in the field of hospital medicine.
Citation
Kattamuri, Lakshmi; Senapati, Sidhartha Gautam; Popuri, Harshitha; Fernandez, Lorena; Sharma, Kunal; Sirineni, Srija; Duvvuru, Sparsha Reddy; Vulisha, Abhinav. (2025). Wernicke's Encephalopathy Secondary to Cannabis Hyperemesis Syndrome.. Journal of Brown hospital medicine, 5(1), 151455. https://doi.org/10.56305/001c.151455
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