NATURAL-HISTORY AND SURVIVAL OF 14 PATIENTS WITH CORTICOBASAL DEGENERATION CONFIRMED AT POSTMORTEM EXAMINATION

Objective-To analyse the natural history and survival of corticobasal degeneration bg investigating the clinical features of 14 cases confir med by postmortem examination. Methods-Patients with definite corticob asal degeneration were selected from the research and clinical files o f seven tertiary medical centres in Austria, the United Kingdom, and t he United States, Clinical features were analysed in detail. Results-T he sample consisted of eight female and six male patients; mean age at symptom onset was 63 (SD 7.7) years, and mean disease duration was 7. 9 (SD 2.6) years. The mast commonly reported symptom at onset included asymmetric limb clumsiness with or without rigidity (50%) or tremor ( 21%). At the first neurological visit, on average 3.0 (SD 1.9) years a fter symptom onset, the most often encountered extrapyramidal features included unilateral limb rigidity (79%) or bradykinesia (71%), postur al imbalance (45%), and unilateral limb dystonia (43%). Ideomotor apra xia. (64%), and to a lesser extent cortical dementia (36%), were the m ost common cortical signs present at the first visit. During the cours e of the disease, virtually all patients developed asymmetric or unila teral akinetic rigid parkinsonism and a gait disorder. No patient had a dramatic response to levodopa therapy Median. survival time after on set of symptoms was 7.9 (SD 0.7) (range, 2.5-12.5) years, and, after t he first clinic visit, 4.9 (SD 0.7) (range, 0.8-10) years. Early bilat eral bradykinesia, frontal syndrome, or two out of tremor, rigidity, a nd bradykinesia, predicted a shorter survival. Conclusion-The results confirm that unilateral parkinsonism unresponsive to levodopa and limb ideomotor apraxia are the clinical hallmarks of corticobasal degenera tion, and only a minority of patients with corticobasal degeneration p resent with dementia. The study also suggests that a focal cognitive a nd extrapyramidal motor syndrome is indicative of corticobasal degener ation. Survival in corticobasal degeneration was shortened by the earl y presence of (more) widespread parkinsonian features or frontal lobe syndrome.