Abstract Background Cobalamin deficiency is a common disorder associated with numerous neuropsychiatric presentations. Prior literature addresses the neurocognitive and affective symptoms, which include psychotic presentations. We present the first reported case of an individual with isolated auditory and visual hallucinations in the absence of other neurocognitive, mood, or psychotic symptoms. Case Report Mr. C, a 74-year-old male with a psychiatric history of PTSD (in remission), presented to the emergency department with one month of gait instability, frequent urinary incontinence while sleeping, and near-daily auditory and visual hallucinations. Given hallucinations, psychiatry was consulted. Mr. C had no other active psychiatric symptoms at time of interview and demonstrated a high degree of insight about his hallucinations. There were no cognitive deficits, delusions, or confusion discernible on exam. Medical work-up was remarkable for vitamin B12 of 148 pg/mL (normal 200-900 pg/mL) and increased red cell distribution width of 17% (normal 11.5-14.5%) with normal folate. Cobalamin was replenished with a 1000 mcg injection of cyanocobalamin and daily oral supplementation (100 mcg). He experienced complete resolution of hallucinations over five days. Discussion Our case demonstrates that hallucinations can be a presenting symptom of cobalamin deficiency without other neurocognitive, psychotic, or mood symptoms. We will review the literature on psychosis and cobalamin deficiency, discuss the neurobiological explanations for neuropsychiatric effects of cobalamin deficiency, and provide diagnostic and treatment recommendations. Conclusion Consultation-liaison psychiatrists should be aware of isolated auditory and visual hallucinations as a presentation of cobalamin deficiency since prompt treatment can lead to rapid resolution of symptoms.

中文翻译：

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老年男性的钴胺素缺乏症和急性发作的听觉和视觉幻觉

摘要背景钴胺素缺乏症是一种常见的疾病，与许多神经精神症状相关。先前的文献涉及神经认知和情感症状，其中包括精神病性表现。我们提出了第一个报告的病例，即在没有其他神经认知、情绪或精神病症状的情况下，出现孤立的幻听和幻视。病例报告 C 先生，一名 74 岁男性，有 PTSD（缓解期）精神病史，因步态不稳、睡眠时频繁尿失禁以及几乎每天出现幻听和幻视而到急诊室就诊. 鉴于幻觉，咨询了精神病学。C 先生在面谈时没有其他活跃的精神症状，并且对他的幻觉表现出高度的洞察力。在考试中没有可辨别的认知缺陷、妄想或混乱。医学检查结果显示，维生素 B12 的浓度为 148 pg/mL（正常值为 200-900 pg/mL），并且叶酸正常时红细胞分布宽度增加了 17%（正常值为 11.5-14.5%）。通过注射 1000 mcg 氰钴胺素和每日口服补充剂 (100 mcg) 补充钴胺素。他经历了五天的幻觉完全解决。讨论 我们的案例表明，幻觉可能是钴胺素缺乏的一个表现症状，没有其他神经认知、精神病或情绪症状。我们将回顾有关精神病和钴胺素缺乏症的文献，讨论钴胺素缺乏症对神经精神病学影响的神经生物学解释，并提供诊断和治疗建议。