Man hallucinates youngsters’ obscene acts, snakes in his sleep; diagnosis goes beyond initial suspicion of dementia

It was a case of dementia. However, the prominent visual hallucinations necessitated a deeper exploration to pinpoint the underlying cause.

ByChetana Belagere

Published May 14, 2024 | 7:00 AMUpdatedMay 14, 2024 | 7:00 AM


For 60-year-old Raju’s family, his behaviour for over three months was very concerning. Raju had begun to complain about seeing snakes in his dreams, leading to fear and disrupted sleep patterns.

Along with this, he expressed concern over witnessing young boys and girls engaged in explicit activities. He would shout and scream at the boys and girls asking them to stop indulging in obscene activities.

His unsettling complaints continued to perplex those around him until his family members decided to seek professional help.

Dr Sudhir Kumar, a noted neurologist from Apollo Hospital in Telangana took a detailed history of the patient and found that there has been memory impairment of a one-year duration.

“He would forget where he kept items of daily use. He would repeatedly ask for food, even after having had the meals,” he explained.

“Over a period, he forgot the names of his relatives and friends. He would get lost while returning home from nearby shops and could not reach the houses of his well-known friends,” added Kumar.

He also noted of the patient: “He had difficulty in calculations and was not able to shop on his own. He required assistance with banking transactions.”

The doctor then pointed out: “Gradually, his self-care also deteriorated. He would not take a bath or brush his teeth unless coaxed by his family members.”

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What was the diagnosis?

Kumar told South First that the clinical diagnosis — given the symptoms mentioned above — was very obvious. “It was a case of dementia,” he explained.

However, the presence of prominent visual hallucinations necessitated a deeper exploration to pinpoint the underlying cause.

He said differential diagnosis — which is when the symptoms of a patient match more than one condition — played a crucial role in narrowing down the possibilities.

While conditions like Diffuse Lewy Body Disease initially seemed plausible, the absence of certain clinical features ruled them out.

“In this case, the two main features were dementia (affecting several cognitive domains) and prominent well-formed visual hallucinations,” noted Kumar.

“In a patient with dementia and hallucinations, the first diagnosis that comes to mind is Diffuse Lewy Body disease (DLBD) or Lewy Body Dementia (LBD). The other diagnosis to consider with such presentation is Parkinson’s Disease Dementia (PDD),” he explained.

He explained that LBD accounted for 30 percent of the cases of dementia in people aged 65 and above. However, the doctor ruled out the LBD as such patients usually present with dementia, extrapyramidal features (such as tremors, slowness, and rigidity), and hallucinations.

“In our patient, extrapyramidal features were lacking. Therefore, LBD could be clinically excluded,” he added.

Similarly, PDD was considered, but deemed unlikely due to the patient’s clinical presentation and medication history.

Kumar explained that patients with PDD also present with extrapyramidal features and dementia. “Dementia is a late feature in patients with PD, and can affect about 10 percent of patients with PD, especially after a decade of the disease onset,” he noted.

“Patients with PD can develop hallucinations due to adverse effects of anti-Parkinsonian drugs (such as trihexyphenidyl, ropinirole, and levodopa). Our patient had no features of PD, and he was not on any anti-parkinsonian drugs, so PDD could be easily excluded,” added the doctor.

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Scans that can differentiate dementias

In such cases, Kumar argued, advanced imaging techniques such as MRI and PET scans emerged as valuable tools in differentiating between LBD and Alzheimer’s Disease (AD).

“MRI and PET scan are the most valuable brain imaging tools to differentiate various types of dementia. MRI brain is an excellent imaging modality to evaluate the structural changes in the brain,” he explained.

He said, there is more profound cortical atrophy in AD, with prominent atrophy of medial temporal lobes. On the other hand, cortical atrophy is less prominent in LBD, with relative preservation of medial temporal lobes.

In LBD, grey matter atrophy is prominent in the posterior parietal regions. In AD, the cortical grey matter atrophy predominantly involves temporoparietal association areas.

These findings are in corroboration with the notion that LBD is a result of neuronal synaptic dysfunction, not neuronal loss.

Meanwhile, in patients with LBD, the FDG-PET scan shows reduced glucose metabolism in occipital lobes, visual association cortices and posterior parieto-temporal areas. In AD, reduced glucose metabolism tends to affect other cortical areas as well.

These imaging modalities provided insights into the structural and functional changes in the brain, aiding in the final diagnosis of Alzheimer’s Disease.

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Hallucinations in AD

Dr Sudhir Kumar explained to South First that hallucinations in AD were not uncommon. However, they were not very well recognised by general public as well as physicians.

He said hallucinations could occur in around 25 percent of cases of AD.

“This means, one in four patients with AD can develop hallucinations. It is associated with greater cognitive impairment and a more rapid deterioration. Hallucinations have also been associated with an increase in mortality,” he explained.

He said about the time of onset that hallucinations have been reported to occur at all stages of AD.

However, their overall presence increases slowly with disease progression. There is no correlation between gender and the development of hallucinations.

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With the diagnosis in hand, Kumar initiated a comprehensive treatment plan for the patient, focusing on managing symptoms and slowing the progression of the disease.

Medications targeting the cognitive decline and visual hallucinations were prescribed, leading to notable improvements during the follow-up visits.

“At the one-month follow-up, his hallucinations had reduced. There was mild improvement in his cognitive functions as well,” recalled the doctor.

“His condition was stable during six months of follow-up. He tolerated the drugs well and did not report any adverse effects,” added Kumar.

He also talked about how Raju’s case was an example of the complexity of neurodegenerative disorders like Alzheimer’s disease and the importance of a multidimensional approach to diagnosis and treatment.

Well-formed visual hallucinations could occur in people with Alzheimer’s disease, and family members would need to be counselled on the response of the patient and some concerning behaviours.

(Edited by Arkadev Ghoshal)