21.1 Case Report

A 73-year-old right-handed man presented with a 1-year history of visual hallucinations. The hallucinations were described as the sight of intruders, about 20–30 people who were seen in his living-room and sometimes threaten him with their eyes. He frequently asked his wife about these people and how she could tolerate their presence. He also made complaints to the front door clerks about allowing these people to enter the building. Sometimes he saw children and animals running around the house. The hallucinations were vivid, well-formed and exclusively visual. He often had psychomotor agitation in response to the visions. Associated with the hallucinations, he began to present forgetfulness described as difficulties in word finding, decreased speed of thought, difficulty reasoning, occasional difficulties in understanding long sentences, and difficulty in learning new information. His relatives noted difficulties in recognition of objects through vision and intense fluctuation in the level of attention, with periods when the patient “stared at the walls” and periods of daytime drowsiness. He had an episode of topographical disorientation where he could not find his way back home. His clinical picture was described as slowly progressive.

The patient was evaluated in another service for the hallucinations, being prescribed a selective serotonin reuptake inhibitor (paroxetine), with worsening of the symptoms. After that, he received low doses of a typical neuroleptic (haloperidol – dose 0.5 mg/day), but had early impregnation symptoms (severe stiffness and bradykinesia) and had to discontinue the medication. During a hospitalization to investigate acute worsening of cognition, he received promethazine and risperidone through psychomotor agitation. Again, he had severe stiffness and drowsiness.

Neurologic examination showed bradykinesia in repetitive movements of the fingers in the left hand with mild stiffness and cogwheel rigidity, which could be caused by previous use of antipsychotics. He also had ideomotor apraxia for transitive (object-related) pantomime gestures. On cognitive evaluation, he scored 18/30 in the Mini-Mental State Examination (MMSE) (time orientation: 2/5; spatial orientation: 4/5; immediate memory: 1/3; attention and calculation: 1/5; evocation: 2/3; naming 2/2; repetition of sentence: 1/1; verbal command: 3/3; written command: 1/1; phrase: 1/1; copy of the pentagons: 0/1). He also had impaired late recall on visual memory, reduced semantic fluency (animals), and visuospatial/executive impairments on the clock-drawing test (Figure 21.1). His score in the Functional Activities Questionnaire (FAQ) was 18. In this questionnaire, score ranges from 0 to 30, with higher scores being indicative of functional impairment.¹

Figure 21.1 Copy of the pentagons (MMSE) and clock-drawing test in the first visit.

Magnetic resonance imaging depicted diffuse mild atrophy, more intense in medial temporal lobes (more evident to the right side) and mild, non-confluent white matter hyperintensities. Fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated bilateral asymmetrical (right more than left) hypometabolism in the temporal and parietal lobes with posterior extension to the occipital lobes (Figure 21.2).

Figure 21.2 Fluorodeoxyglucose positron emission with three-dimensional stereotactic surface projection (3D-SSP): bilateral asymmetrical (right more than left) hypometabolism in the temporal and parietal lobes with posterior extension to the occipital lobes.

21.2 Diagnosis

The main findings in this case were cognitive impairment with well-formed visual hallucinations and evident fluctuations of attention and alertness. Besides, early changes in visuospatial function (difficulty in the copy of the pentagons of the MMSE and very poor performance in the clock design) and extreme sensitivity to neuroleptic medications (early impregnation with low doses of haloperidol and possible neuroleptic syndrome with promethazine and risperidone) had been observed. Even in the absence of spontaneous (nondrug induced) parkinsonism, these features must be a red flag to the diagnosis of Lewy body dementia (LBD).^2–5 LBD is considered the second most frequent cause of degenerative dementia in the senile population (after Alzheimer’s disease – AD) and the third most frequent cause of dementia after AD and vascular dementia.^2–4 LBD is characterized by progressive cognitive decline in which memory may not be the main cognitive domain that is affected initially. Attention, executive functions, and visuospatial processing deficits are often the earliest impaired cognitive functions. In addition to cognitive impairment, central features include spontaneous parkinsonism, visual hallucinations, and fluctuation in arousal and alertness. Additionally, extreme sensitivity to neuroleptic medications, rapid eye movement (REM) sleep behavior disorder, daytime sleepiness, and dysautonomia can be found, in some cases, even before the cognitive and motor symptoms.^{2, 3, 5}

LBD neuropathology is characterized by cortical and subcortical accumulation of Lewy bodies (LB), which are alpha-synuclein-positive intracytoplasmic neuronal inclusions, usually present in the monoaminergic and cholinergic nuclei of the brainstem in idiopathic Parkinson’s disease (PD).^2–6 LBD is very similar to the dementia found in the advanced stages of PD, called Parkinson’s Disease Dementia (PDD), but LBD usually manifests with more severe cognitive and neuropsychiatric impairment and less severe motor symptoms. The “one year” rule has been used to differentiate the two entities, but in clinical practice this didactical split is difficult to apply.⁵ If the cognitive symptoms precede or appear in the first year of the motor symptoms, it is classified as LBD. In cases where the cognitive deficit begins after the first year of motor symptoms, the diagnosis is PDD. This division is arbitrary and probably both entities represent the spectrum of a clinical-pathological continuum.

LBD is characterized by an intense and precocious cholinergic deficit, and some of the symptoms may be more clearly responsive to anticholinesterase medications, at least in the initial clinical phases when compared with AD.⁷