Alzheimer Disease vs Dementia with Lewy Bodies
Dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD) have overhanging features but can be differentiated based on clinical, cognitive, and imaging characteristics. This topic is always asked in NEETPG and INICET exams and hence these tables provide valuable 5-minute read that will help you ace this question like a champion
- Clinical Features
| Features | DLB | AD |
| Cognitive Decline | Fluctuating cognition with pronounced variations in attention and alertness | Gradual and steady decline, primarily affecting memory |
| Hallucinations | Early and well formed visual hallucinations | Late and less prominent hallucinations |
| Parkinsonism | Early -onset (within 1 year of cognitive symptoms), mild, with bradykinesia and rigidity | Late – onset or absent |
| REM sleep behavior disorder (RBD) | Common and often precedes cognitive symptoms | Rare |
| Autonomic dysfunction | Frequent (orthostatic hypotension, urinary incontinence) | Less common and occurs later |
| Neuroleptic sensitivity | Severe sensitivity to antipsychotics | Generally absent |
- Cognitive profile
- DLB: Early deficits in attention, visuospatial skills, and executive function, with relatively preserved memory.
- AD: Early impairment in episodic memory, progressing to language, visuospatial, and executive dysfunction.
- Imaging features:
| Modality | DLB | AD |
| MRI | Relative preservation of medial temporal lobe | Hippocampal and medial temporal atrophy |
| DaT scan (SPECT) | Reduced dopamine transporter uptake in basal ganglia | Normal |
| FDG – PET | Occipital hypometabolism | Temporal parietal hypometabolism |
- Biomarkers
| Biomarker | DLB | AD |
| CSF (Ab & tau levels) | May have normal or slightly altered Ab/tau ratio | ¯Ab42, ↑ total tau and phosphor-tau |
| α-synuclein pathology | Present (Lewy bodies in cortex) | Absent |
- Response to cholinesterase inhibitors
- DLB: Good response, but may worsen tremors
- AD: Modest improvement in cognition