Schizophrenia, bipolar disorder, or intracranial aneurysm? A case report

Abstract Background Mental disorders are a common finding among patients with unruptured intracranial aneurysms. Case The current case concerns a young man with an anterior communicating artery aneurysm who was misdiagnosed with schizophrenia and bipolar disorder due to his significant psychosis and mood episodes. Having undergone surgery on the unruptured intracranial aneurysm, the patient's psychiatric symptoms disappeared, and he maintained a stable mood during the 3‐year postoperative period. Discussion The case is indicative of the need to consider the possibility of organic brain lesions in patients with first episodes of psychiatric presentations.


CASE PRESENTATION
Mr. Z is a right-handed, 28-year-old young male. His symptoms were first manifested at the age of 17, when he complained of headache that felt like lava spreading out within his head. He reported this to his parents. In addition, he also began to experience paranoia, manifest in the proposition that one of his teachers was monitoring him. This manifestation was assumed to be related to the combined pressures of school life and homework. Specifically, the patient regarded the telephone as a monitoring device controlled by a particular teacher. In addition, his constant suspicion that he was under criminal investigation placed him in a perpetual state of fear. Overall, his sense of persecution caused him to feel stressed and unhappy at school. These feelings were expressed as hostility toward his teacher and a refusal to attend school. His parents felt that his behavior was abnormal and took him to a psychiatric clinic where he received a diagnosis of schizophrenia (based on ICD-10 criteria) and was subsequently treated with mirtazapine (up to 90 mg/day) and quetiapine (up to 300 mg/day). Moreover, he developed an unusual strong interest in pornography and easily became extremely excited when talking with his female classmates. Believing himself to be cured, the patient discontinued his medication when he was 19, without consulting his psychiatrist. Due to his poor performance in the National Higher Education Entrance Examination, he was obliged to attend a junior college instead of a university.
Subsequently, he struggled to complete his studies at junior college and became an office worker. He continued to suffer from repeated, albeit less severe mood swings and paranoia following a renewed onset of minor headache. Moreover, he did not have any period of emotional stability for more than 3 months. Consequently, he found it challenging to complete tasks and maintain relatively harmonious relationships with others.
Eight years after the initial onset of his delusions and 7 years after the first episode of detectable mood disorder, he attended an emergency department at age 25, having experienced a sudden onset of severe headache and nausea.
The physical examination performed upon admission found the patient to possess a painful demeanor. He was clearly conscious, with stable vital signs, and regular and coordinated limb movement. Both

DISCUSSION
Intracranial aneurysms are estimated to have a prevalence of 3.2% of the adult population worldwide, with peak onset between 40 and 60 years of age. Intracranial aneurysms are acquired lesions that are caused by degenerative changes in vessel walls. Some increase in size over a period of hours, days, weeks, or several years, and eventually either rupture or undergo stabilization and hardening. Most intracranial aneurysms are asymptomatic prior to rupture, although some patients may present with symptoms such as headache, transient ischemic attack, cranial neuropathies, double or blurred vision, and seizures (Thompson et al., 2015).
The early detection of unruptured intracranial aneurysms continues to present a challenge due to their nonspecific physical and psychological symptoms. As such, patients with unruptured intracranial aneurysms are occasionally misdiagnosed with psychogenic disorders.
Prior to the aneurysm rupturing, the patient in the current case presented with sporadic, endurable headaches, no visual irregularities, and no pyramidal dysfunction. However, the patient had experienced discernable mood swings and feelings of paranoia. The combined administration of mood stabilizers and atypical antipsychotic drugs caused both the headaches and psychological symptoms to improve. The psychiatrists' focus on the psychiatric symptoms exhibited by patient Z caused the progress of the physical manifestations to be overlooked.
Consequently, neither the psychiatrist nor the patient requested any imaging examination. Had they done so, the root cause of the symptoms would become clear. However, the patient's underlying illness remained undiagnosed.
A review of the treatment process suggests that several stages in the treatment process should be reviewed. First, the patient initially presented with headaches for which there was no clear cause. Rather than assuming that the headaches were a symptom of a psychiatric illness, it would have been preferable to have conducted cranial imaging evaluation at this early stage in order to rule out any organic abnormalities. Second, throughout the course of the disease, the patient's mental symptoms and headaches always occurred concurrently. The psychiatrist treated the patient with valproate, which is reported to be effective in preventing migraines, with the dosage being in the range of 500-1500 mg/day (Pringsheim et al., 2010). Therefore, even if the patient's headache reduced after using the drug, it was not possible to conclude that the improvement of the bipolar disorder symptoms was the cause of the headache relief. Third, the patient presented an inadequate response to effective doses of mood stabilizers and second-generation antipsychotics. He also showed confabulation, changes in personality, and impairment in memory, learning, attention, and executive functions, all of which are consistent with the neurobehavioral disturbances associated with intracranial aneurysms (Bottger et al., 1998 (Madhusoodanan et al., 2007). Adopting these measures may help to ensure that the possibility of intracranial organic lesions can be excluded as a cause of symptoms prior to the diagnosis of a mental disorder.
The specific clinical manifestations of patient Z also emphasize the importance of individualized diagnosis. Current research indicates that normative models can effectively reveal heterogeneous biology at an individual level (Marquand et al., 2019). Healthy individuals usually do not deviate significantly from the normative model. Patients with schizophrenia typically demonstrate significant reductions in gray matter in their frontal lobes, cerebellum, and temporal cortex.
Conversely, patients with bipolar disorder present with differences that are primarily confined to cerebellar regions (Wolfers et al., 2018).
In summary, the psychiatric symptoms caused by anterior communicating artery aneurysms could present in a manner akin to those caused by either schizophrenia or bipolar disorder. This case highlights the need for an elaborate differential diagnostic process, such as brain imaging, in cases where headaches are among the initial symptoms.