History and onset of Capgras Delirium after Subarachnoid Haemorrhage (SAH)
59-year-old female patient with a degree in exact sciences and former high school teacher. She is the eldest of three siblings. She describes her happy childhood, was very close to her father, was an outgoing, sociable and independent child. Intellectually brilliant, she soon lived independently, moving several times from city to city according to professional requirements. She had a psychotic break with paranoid ideation at the age of 30 after her planned wedding was called off. The manic and depressive episodes alternated, some of them requiring hospital admission, although she was able to lead a normal life without work-related problems between periods until the third of her admissions in 2005, motivated by a depressive episode and coinciding with the recent death of her father, at which time the patient applied for work incapacity (absolute ILP granted in 2006). The relapses were always related to the abandonment of lithium treatment. Alcohol abuse was also observed during this time. Diagnosis until December 2009: "Bipolar disorder with congruent and non-congruent psychotic symptoms, with remission" and "Alcohol abuse". Since she became independent she has hardly any relationship with her parents and siblings, because of her lifestyle and manic symptomatology she is considered the "black sheep" of the family.
In 2009 she suffered a subarachnoid haemorrhage (SAH). The CT scan revealed left temporoparietal involvement surrounded by extensive oedema; mass effect on the ipsilateral ventricular system and acute left parietal haematoma with severe involvement of the level of consciousness, sensitivity, motor skills and speech. On waking up from the coma, he says that the first thing he sees is the face of a former teacher colleague with whom he had an affectionate relationship. After this he says that his siblings "are not his siblings", attributing the change to the teacher friend. The CD extends to friends and acquaintances. Abandoned by her partner at the time, it is the brother who takes responsibility for her care.
Evolution of the case after SAH. Subsequently, she required several hospital admissions due to decompensation of psychiatric symptoms; asymptomatic periods practically ceased. In the acute unit prior to admission to the EMU he presented: potomania, psychotic decompensation with paranoid-type delirious ideation, kinaesthetic hallucinations, social isolation and disorganised thinking, hyperthymic mood, insomnia, and slight disinhibition. Lithium salts were withdrawn due to nephropathy secondary to diabetes insipidus, and valproic acid was introduced. Diagnosis: "Mixed schizoaffective disorder, with congruent and non-congruent psychotic symptoms"; "Alcohol abuse". In February 2012 he was admitted to the EMU to start an "individualised rehabilitation plan".
- The medical-nurse assessment found moderate functional limitation with generalised hypotonia. History of hypothyroidism and NIDDM, both in remission. Potomania and enuresis secondary to episodes of nephrogenic diabetes insipidus that were corrected with self-registration and thiazides.
- The neuropsychological examination (WAIS IV) showed cognitive impairment in both working memory and processing speed, although the levels reflect a "normal" level, around an IQ of 100, which was previously assumed to be much higher given his academic and professional history. He exhibits socially inappropriate verbal behaviour suggesting frontal involvement, perhaps as a result of his long history of alcohol abuse.
- Psychopathological evaluation: Presence of several delusions of bodily influence, telepathy and DC, and some simple hallucinatory phenomena. The same teacher who causes impersonation also throws things at him and pushes him. He communicates telepathically with him through the numbers on the TV and the clicks he hears in the windows. The characteristics of the CD are shown in table 1. It should be noted that although at the beginning he showed some hostility towards the "brother's double", his feelings became positive, in fact he now gets along much better with him than before the SAH episode. Psychopathological stabilisation is achieved with Depakine 1300 mg/day, Olanzapine 20 mg/day, Risperidone 6 mg/day, Vitamin B Complex. He participates in the "treatment adherence group". Discharged in December 2012. Residual positive psychotic symptomatology and partial insight.

