A case of progressive posterior cortical atrophy (PCA) with vivid hallucination: are some ghost tales vivid hallucinations in normal people?

Patients with Parkinson's disease (PD), diffuse Lewy body disease (DLBD), or dementia with Lewy body disease (DLB) unaccompanied by paranoia, delusions, REM sleep behaviour disorder, or an obvious sleep problem sometimes report experiencing extremely vivid visual hallucinations (VH) of ghosts or monsters.¹,² Here we describe two VH experienced by a patient with progressive posterior cortical atrophy (PCA) which are similar to Japanese folktales and personal ghost stories.

Case report

The patient was a 60 year old man who complained that he had begun to see ghosts frequently. He noted difficulty in writing when he was 57 years old because he could not remember Japanese characters well, and this was accompanied by severe insomnia. He frequently had VH both during the day and at night. Two typical hallucinations are described below.

(1) The patient was at home when suddenly six people broke into his living room and started cooking silently. He asked them why they had come and what they were doing, but no one answered. He questioned them repeatedly and tried to tap one on the shoulder, but as soon as his hand touched the ghost's shoulder, they all vanished instantaneously.

(2) One night, when the patient went to the toilet, he found his wife lying in the corridor stabbed to death and bleeding profusely. Although it was midnight and completely dark, he could see the fresh blood coming out of her neck wound. He was astonished and tried to help her up, but all images vanished as soon as he touched her.

Neurological examination showed Bálint syndrome accompanied by dressing apraxia, constructional apraxia, agraphia, and dyscalculia. The patient's mini‐mental state examination (MMSE) score was 17/30. He showed no bradykinesia, muscle rigidity, or finger tremor. He was also seen by a psychologist who found no emotional problems. MRI revealed bilateral parieto‐occipital, occipital, and mild left temporal cortical atrophy (fig 1), and cerebral perfusion estimated by xenon CT perfusion showed decreased cerebral blood flow in the bilateral parietal and frontal regions. CSF showed no abnormality. Administration of 10 mg/day of propericyazine ameliorated the VH.

Figure 1 MRI imaging of patient. T1 and T2 images show bilateral parieto‐occipital, occipital, and mild left temporal atrophy in horizontal (A) and coronal (B) sections.

The VH experienced by this patient resembles a ghost story published by the Japanese essayist Shinya Nishimaru nearly 50 years ago.³ One night when he was 23 years old, Shinya Nishimaru encountered a lady leaning against a concrete wall outside a factory. Although it was a dark, moonless night, he noticed the pattern of her clothes and outlines of her face and eyes precisely. At first, she appeared in the open air, but after 1 year began appear beside his bed. When he tried to touch her or hit her with a club, she disappeared as soon as he touched her clothes. One night, she suddenly looked him in the eye which really frightened him. He could hardly sleep a wink for several days, which made him fear for his life, so he fled the town. (A longer version of this story together with other ghost stories can be found in the supplemental information available at http://www.jnnp.com/supplemental.)

This hallucination is characterised by (i) the ghost appearing without any relation to sleep at first, (ii) purely visual hallucinations (that is, the ghost never talked or tried to touch him, and the image of the ghost was very clear), and (iii) the ghost vanishing when he tried to touch it. He consulted a psychiatrist but was diagnosed as sane. However, he later saw another vivid ghost while he was mountain climbing.

We also found ghost tales resembling the VH of our case in a record of authentic Japanese folklore written almost 100 years ago. Toh‐no Monogatari (The ‘Toh‐no' Folktales) edited by Kunio Yanagida, a famous Japanese folklorist, evaluated more than 300 short verbatim records of face to face encounters from old Japanese folklore, especially those involving traditional Japanese monsters, goblins, and elves. In Toh‐no Monogatari, we also found two other stories that referred to VH of ghosts, although both of them were experienced by children.⁴

Discussion

Although neuropathological examinations were not performed, our patient was diagnosed as having PCA with VH and the cause was considered to be DLBD or Alzheimer's disease on the basis of the clinical symptoms.¹,⁵

The VH of this patient are quite similar to descriptions in Japanese folktales and personal ghost stories. When we investigated these stories from a neurological point of view, we noted several similarities between the stories and the VH common in patients with DLBD, PD, DLB, or Charles Bonnet syndrome (CBS).¹ VH is usually considered one of the clinical symptoms of DLBD, PD with late developing dementia and rapid cognitive decline, and DLB.¹,² Similar VH are also reported in CBS, which was originally observed in elderly and visually impaired people without psychiatric or neurological problems. However, a close resemblance between CBS and PD related VH is also suggested.¹

Recent neuropathological and radiological studies revealed that VH in CBS are associated with hyperperfusion of the temporal cortex, striatum, and thalamus, as well as increased cerebral activation in the ventral extrastriatal region, while DLB patients with VH showed hypoperfusion or hypometabolism of the occipital cortex.¹ It was also reported that PD patients with VH also have alterations in or decreased cerebral activation in the temporo‐parietal, parietal, and occipital regions.¹ Our patient showed atrophy of the bilateral parieto‐occipital, occipital, and mild left temporal lobes and decreased cerebral perfusion in the parietal and frontal lobes, indicating that the VH in our case may be caused by dysfunction of these regions. Such VH are rarely experienced by normal people, but, once seen, some people may be convinced they are supernatural events. We neurologists pay attention to such reports, and note the similarity in content between ghost tales and VH, and pursue their mechanism of origin.

In conclusion, we propose that some ghost sightings are actually VH in normal people, which occur very rarely but more frequently than we in the medical establishment think.

Electronic‐database information

A longer version of the story by Shinya Nishimaru together with other ghost stories can be found in the supplemental information available at http://www.jnnp.com/supplemental.