"String hallucinations": a case of Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) with multimodal visual and somatic disturbances.

Introduction: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a hereditary condition primarily caused by mutations on the NOTCH3 gene, leading to hypoperfusion and ischaemic events, with two-thirds of cases having lacunar infarcts mostly within the basal ganglia, thalamus, and brainstem. Here, we focus on an individual with CADASIL who had a thalamic stroke, which preceded symptoms of visual and somatic disturbances.

Methods: A single-case report is used to describe the visual and somatic disturbances experienced by a 52-year-old gentleman following a left-sided thalamic stroke, who is genetically heterozygous for c449A > G p.(Tyr150Cys) mutation in the NOTCH3 gene consistent with CADASIL, as well as their response to various psychotropic medications, through information gathered from the patient's clinical records.

Results: After trialling several antidepressants, and a trial of a cholinesterase inhibitor, there was no perceived benefit reported; with only lamotrigine, previously prescribed for thalamic pain, and olanzapine, providing the least amount of distress associated with their symptoms.

Conclusions: As the management of CADASIL appears to focus on symptom control, this case highlights the need for further research to elucidate the mechanisms driving such unusual perceptual disturbances to inform potential future treatments.