Table 1 Comparison of autosomal-dominant Alzheimer's disease with sporadic Alzheimer's disease
Measure | ADAD findings | SAD findings |
|---|---|---|
Clinical presentation | Episodic (recent) memory and judgment impairment in most; seizures and myoclonus not rare | Episodic (recent) memory and judgment impairment in most; seizures rare in early disease, more common in late disease |
Atypical presentation | Yes - behavioral presentations; spastic paraparesis | Yes - behavioral and language presentations; posterior cortical atrophy |
Age of onset | < 60 years for most, can be as early as mid-20s; > 60 years rarely reported | > 60 years for most; <50 years rarely reported |
Duration of illness | Average 6 to 9 years | Average 7 to 10 years |
Atrophy - volumetric MRI | Hippocampal atrophy, temporo-parietal cortical loss | Hippocampal atrophy, temporo-parietal cortical loss |
Hypometabolism - FDG-PET | Temporo-parietal hypometabolism | Temporo-parietal hypometabolism |
Amyloid imaging - PiB-PET | Precuneus/posterior cingulate and prefrontal; consistent striatal binding | Precuneus/posterior cingulate and prefrontal; less consistent striatal binding |
Pathology | Plaques and tangles in all; CAA in most; cottonwool plaques in some | Plaques and tangles in all; CAA in most |
CSF Aβ42 | Decreased | Decreased |
CSF tau, p-tau181 | Increased | Increased |
Blood Aβ42/Aβ40 ratio | Increased | Variable |