A new medical report details the case of a woman who started showing strange "altered behavior" and was diagnosed with dementia for five years. However, her symptoms were actually reversible.

The unnamed woman, discussed in BMJ Case Reports, started exhibiting a gradual change in behavior, which was noticed by her family. As well as no longer cooking, keeping her house tidy or washing properly, she started to show worrying signs associated with dementia. She walked naked through the streets near her house in Cape Verde and sometimes appeared to be talking to people who weren't there.

The 61-year-old was taken to the hospital by her sister after she witnessed her losing consciousness and suffering jerky seizure-like movements. Here, she was given blood tests and a CT scan of her head, both of which showed no signs of abnormalities. An EEG of her brain showed generalized slowing, but no epileptiform activity (EEG patterns consistent with epilepsy). However while in the hospital's care, she went on to have another seizure and was sent home with medication.

At home, she continued to show psychotic symptoms.

"She continued talking and shouting about the spirits of dead relatives whom she could see clearly and who told her not to take her medication," her sister told her doctors.

She believed her family were trying to poison her and wouldn't share meals with them. As well as this, she continued to struggle to remember things and would get lost and distracted easily, making her unable to return home alone upon leaving the house.

Referred to the Department of Psychiatry at the Nova Medical School in Lisbon, she was found to have a vitamin B12 deficiency. The vitamin, found mainly in fish, meat, dairy, and eggs, is important for brain function as well as forming red blood cells.

The doctors believe that the deficiency damaged the fatty layer around her spinal cord, which led to the degeneration of her backbone and triggered psychotic symptoms, Brinkwire reports.

After five years of dementia-like symptoms, the woman was diagnosed with pernicious anemia, an inability to make enough healthy red blood cells, and doctors were able to treat her properly.

"The patient had a remarkable neuropsychiatric recovery after vitamin replacement and psychopharmacological management," the authors write in the report.

She was given a vitamin B12 supplement called cyanocobalamin, as well as an anti-psychotic medication. Soon after this treatment, she stopped showing signs of psychosis and aggressive behavior.

"The patient’s cognitive status improved dramatically," the authors write. "She became oriented in time and space, her speech became coherent and logical, and her functional status returned to what her relatives considered to be normal. She could now cook, help around the house, go out shopping and be entirely independent in daily activities."

The doctors who wrote the case report, titled "Reversible dementia, psychotic symptoms and epilepsy in a patient with vitamin B12 deficiency", note that cognitive decline combined with psychosis and seizures is an extremely rare occurrence in people with vitamin B12 deficiencies.

They urge clinicians to consider vitamin B12 deficiencies when diagnosing patients with psychosis and seizures, especially when seen with cognitive decline.

"Our case suggests that dementia associated with vitamin B12 deficiency can still be reversed with vitamin replacement therapy, even after a prolonged deficit status."