Physician Memorial Healthcare Organization Hollywood, Florida, United States
Case Diagnosis: New onset visual hallucinations in an Embolic Stroke Patient
Case Description: 76 year old female with a history of visual impairment secondary to glaucoma, hypertension, and hyperlipidemia was admitted to acute inpatient rehab with cortical, cerebellar, and basal ganglia embolic strokes. She was started on modafinil 100 milligrams daily for post stroke neurostimulation. The following day, her therapist reported she was engaging more during therapy sessions, but she was also having significant, new-onset visual hallucinations leading to the discontinuation of modafinil.
Discussions: Although rare, hallucinations are a known, serious potential side effect of modafinil use. During Modafinil clinical trials, the majority of the patients that experienced hallucinations had a history of psychiatric illness and were taking high daily doses. This patient did not have either of these risk factors leading to questions as to why she developed visual hallucinations. One hypothesis is that in this patient modafinil lead to increased stimulation of the cortical visual areas leading to, essentially, a medication induced Charles Bonnet Syndrome (CBS). CBS is a phenomenon where patients with acquired vision loss develop complex visual hallucinations. The proposed pathophysiology involves visual sensory deafferentation leading to excessive cortical compensation which results in visual hallucinations.
Conclusions: Modafinil is a common pharmacologic agent used in post stroke patients for neurostimulation. Per clinical trials of modafinil, patients with psychiatric illnesses and those taking high daily doses had the greatest risk of developing visual hallucinations as a side effect. Further research could assess if stroke patients with acquired visual impairments are more likely to develop visual hallucinations from modafinil compared to patients without visual impairments. This would support the hypothesis of pharmacologic neurostimulation with modafinil inducing CBS.
