Essential tremor-Parkinson's disease: A double whammy

Abstract

Background Surprisingly little has been written about the combined clinical entity, essential tremor-Parkinson’s disease (ET-PD), which is the result of a double disease hit. We carefully quantified tremor burden using a wide range of measures (tremor severity, tremor-related disability, tremor-related quality of life) and furthermore, studied additional motor and non-motor features in ET-PD. Methods In this prospective, clinical-epidemiological study, we performed a standardized, structured clinical evaluation of 27 ET-PD patients, comparing them to age-matched samples of 35 PD and 109 ET patients. Results The number of hours/day shaking was lowest in PD (median = 3.0), intermediate in ET (median = 10.0) and highest in ET-PD (median = 14.0) (p<0.001). All measures of mobility and balance (Berg Balance test, Activities-specific Balance Confidence Scale, Timed Up and Go test) worsened across groups in a stepwise manner from ET to PD to ET-PD (p<0.05). Mini-mental state test scores worsened (p = 0.002) and daytime sleepiness increased (p = 0.002) across groups from ET to PD to ET-PD. Conclusions The ET-PD patient seems to be more than just a PD patient with a little more kinetic tremor. Aside from a significantly greater tremor burden, ET-PD patients exhibited more cognitive and sleep problems and more mobility and balance problems than patients with isolated PD.

Emerging concepts on bradykinesia in non‐parkinsonian conditions

“…In addition, the presence of bradykinesia in patients with HD may indicate a specific disease variant, namely, the Westphal variant. Patients with hyperkinetic movement disorders may also develop bradykinesia during the disease course, as in late stage HD [84] or in ET‐PD [186]. This also implies that patients who have initially been diagnosed with a non‐parkinsonian condition may possibly require treatment for bradykinesia when clinically relevant.…”

Parkinsonism in essential tremor cases: A clinicopathological study

“…Some elderly individuals may therefore have both ET and PD by chance alone. There is ongoing debate over the frequency of co‐occurrence, clinical diagnosis, course, long‐term clinical profile, different PS variants, and the significance of the co‐prevalence of PS in ET cases …”

“…Several clinical and epidemiological studies have reported on the ET‐PD co‐prevalence . Significance of such studies is limited because the brain pathology was not identified.…”

“…Several clinical and epidemiological studies have reported on the ET-PD co-prevalence. 6,14,21,23 Significance of such studies is limited because the brain pathology was not identified. One clinicopathological study suggested an increased risk of PD, 20 but another reported higher risk of PSP 25 in ET cases.…”

The features of the pathogenesis and clinical picture of Parkinson's disease that has developed in essential tremor

“…При сравнительном анализе моторных симптомов не выявлено различий между группами ЭТ-БП и БП на одинаковых стадиях болезни [20,24,25]. Ряд авторов сходится во мнении, что выраженность тремора у пациентов с ЭТ-БП больше, чем у пациентов с БП и даже ЭТ [20,[25][26][27][28], и только в исследовании R.М. Simoes и соавт.…”