Rapidly progressive neurodegenerative dementias.

BACKGROUND: Neurodegenerative dementias are typically characterized by an insidious onset and a relatively slowly progressive course. Less common are patients with a rapidly progressive course to death.
OBJECTIVE: To characterize patients with a neurodegenerative disease and a rapidly progressive course to death. DESIGN, SETTING, AND PATIENTS: Using a text word search for "rapid" and "dementia" in the same sentence, the Mayo Clinic Medical Records Linkage system was used to identify all patients evaluated between January 1, 2000, and September 30, 2007, with brain autopsy (N = 96) at a tertiary care medical center. Of these 96 patients, we included only those with disease duration of less than 4 years to death and with histological diagnosis of a neurodegenerative disease. MAIN OUTCOME MEASURES: Rapidly progressive dementia with death sooner than 4 years after onset and pathological diagnosis at our institution of a neurodegenerative disease.
RESULTS: We included 22 patients (10 men). Although 8 cases (36%) had Creutzfeldt-Jakob disease (CJD), the rest had frontotemporal lobar degeneration with motor neuron degeneration (5 cases [23%]), a tauopathy (progressive supranuclear palsy or corticobasal degeneration) (4 cases [18%]), diffuse Lewy body disease (3 cases [14%]), or Alzheimer disease (2 cases [9%]). All of the patients with CJD died 12 months or sooner after onset, whereas the others had an illness duration longer than 12 months. Notably, all of the 3 patients with diffuse Lewy body disease but no others initially experienced a transient postoperative or illness-associated encephalopathy, then relative normality for 2 years, and finally a rapidly progressive dementia and decline to death in 4 to 12 months.
CONCLUSIONS: Based on this cohort, although CJD is the most likely cause of a rapidly progressive neurodegenerative dementia, frontotemporal lobar degeneration with motor neuron degeneration, diffuse Lewy body disease, tauopathies, and Alzheimer disease can also cause a rapidly progressive dementia. If illness duration is beyond 12 months, a non-CJD neurodegenerative disease may be more likely than CJD to be the diagnosis.