Table 2.

Clinical Features of Parkinsonism and Dementia in Cases with Essential Tremor

Case #	Parkinsonism on Neurological Examination	Latency from ET to Parkinsonism on Neurological Examination (y)	PD or Atypical Parkinsonism Diagnosed During Life	Treated with carbidopalevodopa	Cognitive Complaints	Normal Cognition on Examination	Clinical Diagnosis of Dementia	Latency from ET to Dementia (y)	Latency from last neurological examination to death (m or y)
1	RT, B, ePI	20	Yes (PD, age 76)	Yes	No	Yes	No	NA	1m
2	None	NA	No	No	Yes	No	Yes (AD, age 93)	5	5.5 y
3	RT, B, ePI, deep NLFs	45	No	No	Yes	No	Yes, (Dementia, age 88)	47	3.5 y
4	RT only	NA1	No	No	Yes	No	Yes (AD, age 96)	44	1 y
5	RT, + pull test	28	No	No	No	Yes	No	NA	1 y
6	RT, B, R, PI	41	Yes (PD, age 76)	Yes	Yes	No	Yes (Dementia, 75)	40	9 m
7	RT, +pull test	35	No	No	No	Yes	No	NA	8 m
8	RT, hypophonia	49	No	No	Yes	Yes	No	NA	3 m
9	RT, mild B, + pull test	68	No	No	No	Yes	No	NA	1.5 y
10	RT, mild B, mild hypomimia	11	No	No	No	Yes	No	NA	1 y
11	RT, R	35	Yes	Yes	No	Yes	No	NA	4 m

AD = Alzheimer disease, B = bradykinesia, ePI = early postural instability, ET = essential tremor, F = female, L = left, NA = not applicable, m = months, NLFs = nasolabial folds, PD = Parkinson disease, PI = postural instability, R = right, RT = rest tremor, y = years, + = positive

¹Case 4 only had mild rest tremor in the setting of severe, longstanding ET. There was no bradykinesia or other features of parkinsonism.