PT  - JOURNAL ARTICLE
AU  - J R Hodges
AU  - D P Salmon
AU  - N Butters
TI  - Differential impairment of semantic and episodic memory in Alzheimer's and Huntington's diseases: a controlled prospective study.
AID  - 10.1136/jnnp.53.12.1089
DP  - 1990 Dec 01
TA  - Journal of Neurology, Neurosurgery & Psychiatry
PG  - 1089--1095
VI  - 53
IP  - 12
4099  - http://jnnp.bmj.com/content/53/12/1089.short
4100  - http://jnnp.bmj.com/content/53/12/1089.full
SO  - J Neurol Neurosurg Psychiatry1990 Dec 01; 53
AB  - A controlled prospective study compared the performance of 14 patients with dementia of Alzheimer type (DAT) and 14 patients with Huntington's Disease (HD), who were matched for overall level of dementia, on a battery of semantic and episodic memory tests. The DAT patients were significantly more impaired on measures of delayed verbal and figural episodic memory, and in addition showed a more rapid rate of decline on tests which depend upon the integrity of semantic knowledge (naming, number information, similarities and category fluency). In contrast, the HD patients were significantly worse, and showed a more rapid decline on the letter fluency test, a task especially sensitive to deficiencies in retrieval. The HD patients were also more impaired than DAT patients on a vocabulary test and on copying geometric figures. The observed double dissociations offer compelling evidence that aetiologically distinct forms of dementing illness result in different patterns of cognitive impairment.