Dementia With Lewy Bodies: Case Assessment and Diagnosis

Clinical Presentation

Patient KM's current medication is Prothiaden, which is used to treat depression and to limit feelings of anxiety. The case file indicates a normal MRI and no previous diagnosis of neurological disorders such as Parkinson's disease. Patient KM has complained of depression and anxiety related to the passing of her mother. Progressive functional and cognitive decline has been present ever since her mother died four years ago.

Although the patient worked until the age of 60 as an accountant, within the last 18 months she has experienced fluctuations in mood, confusion, mild word-finding difficulties, and spatial disorientation. She also reports visual hallucinations and violent dreams. She has experienced recent falls and a slowing of motor skills. These symptoms extend to an inability to carry out motor sequences with either hand or double alternating hand movements. Although she can detect shapes well, she has poor ability in number location and dot counting. When instructed to draw a cube, she did so well; however, when instructed to draw a cross, she could not form one properly. She was also unable to draw the hands on a clock, though she could draw the clock face itself.

Neuropsychological Assessment

Dementia with Lewy bodies (DLB) has a notably faster progression than Parkinson's disease; Parkinson's progression typically takes between 10 and 20 years, whereas Lewy body dementia can progress within 18 months — consistent with KM's presentation. KM's REM-circadian sleep disorder also points toward a Lewy body diagnosis. The clinical information reveals numerous indicators of functional decline, a crucial identifier for dementia.

Alzheimer's disease (AD) can be ruled out based on KM's neuropsychological scores. Her predicted (pre-morbid) IQ, as rated by the National Adult Reading Test, was average, despite her 17 years of education. On the Wechsler Adult Intelligence Scale – Third Edition (WAIS-III), which uses a maximum score of 10, KM scored 6 (1.3 standard deviations from the normative data), classifying as borderline; a score of 10 is intact, and a score of 5 or below is considered impaired. Her WAIS-III subtest scores were as follows: picture completion — above average; similarities — above average; comprehension — borderline average; block design — impaired; digit span — impaired; information — intact; arithmetic — borderline average. Her average, above-average, and intact scores on the Wechsler Memory Scale – Third Edition (WMS-III) serve to rule out AD.

There is marked impairment as shown in the Rey Complex Figure Test. The Controlled Oral Word Association Test (COWAT) score was −6, indicating severe impairment. The Colour Form Sort, which identifies flexible thinking ability, revealed significant impairment as KM was unable to complete it. The Trail Making Test Part A was impaired, and Part B was discontinued. Depression, Anxiety and Stress Scale scores suggest possible toxicity to the hippocampus, which can cause dementia.

The physical assessment, including asking the patient to draw the time on a clock, produced mixed results. KM can see a clock and identify its numbers but cannot position the hands to indicate a specified time. The lowest raw scores were in mental control (11), visual reproduction percentage retention (8), digit span (7), and block design (4). The patient also reported vivid hallucinations, such as seeing "elephants in the house," acts out violent dreams, and experiences confusion and memory lapses. Her recent falls indicate potential neurological problems.

Differential Diagnosis

Several major neurodegenerative conditions share parkinsonian features, which may include bradykinesia, tremor, rigidity, and gait disturbances (Gaddipati and Umaiorubahan, 2014). Such disorders have multifaceted clinical presentations reflecting degeneration across numerous neuronal systems. Because of their shared parkinsonian features, these illnesses have been collectively termed Parkinson-plus syndromes. People with these conditions frequently have a history of responding poorly to standard Parkinson's disease treatment protocols. An insufficient response to treatment in a patient presenting with parkinsonian symptoms suggests the possibility of a Parkinson-plus condition, warranting further investigation for signs of degeneration in other neuronal systems (Hohler and de Leon, 2011, p. 1860).

In addition to a lack of response to dopamine agonists or carbidopa/levodopa (Sinemet) in the early phases of illness, other clinical signs indicative of Parkinson-plus conditions include the following:

Modern immunocytochemical methods and genetic findings suggest that Parkinson-plus syndromes can be classified into two types: tauopathies and synucleinopathies. Clinically, researchers have identified five distinct Parkinson-plus conditions:

Corticobasal ganglionic degeneration (CBGD) is a sporadic neurodegenerative tauopathy that manifests as both a movement disorder and a cognitive dysfunction syndrome — known as corticobasal syndrome — as well as a medically defined illness. Corticobasal syndrome is characterized by progressive dementia, limb apraxia, and Parkinsonism; however, these features may arise from a variety of pathological substrates (Armstrong et al., 2013). The most typical are Pick complex disorders, but Alzheimer's disease and even rare conditions (such as Niemann–Pick type C and CNS Whipple disease) can also be associated with corticobasal presentation. Histopathologically confirmed CBGD may also present clinically as primary progressive apraxia or primary progressive aphasia, even in patients who had no prominent movement disorder earlier in life.