Essential tremor — Neurodegenerative or nondegenerative disease towards a working definition of ET

Abstract

Essential tremor (ET) is a syndrome of tremor in posture and movement, but recent studies have revealed additional cerebellar motor disturbances, cognitive disturbances, personality changes, hearing loss, and olfactory deficits. Even dementia and shortened life expectancy were found in one cohort. Recent postmortem studies have found limited Lewy body pathology in some patients and Purkinje cell loss with torpedoes and Bergmann gliosis in others. These findings have led to the hypothesis that ET is a syndrome produced by at least two neurodegenerative diseases with more widespread clinical consequences than previously appreciated. We review the evidence for and against this hypothesis and conclude that studies purporting to support this hypothesis have failed to control for age-associated comorbidities, depression, medications, and other confounding factors. We propose the alternative hypothesis that abnormal neuronal oscillation is the fundamental abnormality in ET, and the well-documented cerebellar signs and symptoms, the controversial non-motor signs, and even the cerebellar pathology of ET could be caused by this oscillation. A major problem for many studies is the lack of a diagnostic gold standard. Lacking such a standard, we propose a subclassification of ET into three categories: hereditary ET, sporadic ET, and senile ET, which we believe will help researchers resolve many of the controversies in this field.

Gait disorders and postural instability in patients with an essential tremor

“…Более раннее и ча-стое развитие нарушений тандемной ходьбы наблю-далось у пациентов с ЭТ, манифестировавшим по-сле 60 лет, что в целом поддерживает представления о возрастной гетерогенности этого заболевания [5]. Об этом же свидетельствует связь нарушений тан-демной ходьбы с аксиальными видами тремора (тре-мор головы и голосовых связок), которые более вы-ражены при позднем начале ЭТ [9,11].…”

“…Нейропсихологическое обследование свидетельствует об участии мозжеч-ка и его связей с лобной корой в развитии умерен-ного когнитивного дефицита, связанного с ЭТ [12][13][14]. Природа дисфункции мозжечка при ЭТ остается до конца не установленной, клиническая значимость минимальных дистрофических изме-нений, выявленных в немногочисленных патомор-фологических исследованиях, остается неясной [5,8]. О своеобразной природе дисфункции мозжечка при ЭТ свидетельствует парадоксальная нормали-зация ходьбы у пациентов с ЭТ при алкогольной пробе [10].…”

“…С одной стороны, это показывает, что нарушение тандем-ной ходьбы может играть роль своеобразного ин-дикатора общей тяжести заболевания. С другой стороны, его можно рассматривать как косвенное подтверждение гипотезы G. Deuschl и R. Elble, со-гласно которой дисфункция мозжечка при ЭТ мо-жет носить вторичный характер и объясняться вли-янием патологической колебательной активности, генерируемой в таламусе, базальных ганглиях и стволовых ядрах [5].…”

Novel Treatment Options for Advanced Parkinson’s Disease

“…6 In animal models of PD, neuronal activity is abnormally increased in the STN and These adverse events are most frequent during the first weeks after surgery and are often related to the complex interaction between drug withdrawal and stimulation adjustment during this initial stabilisation period. 9 Because STN-DBS aims at improving a patient's functional capacity and reducing disability by alleviating motor fluctuations and dyskinesia, it was important to prove that quality of life is indeed improved despite the potential adverse effects of the therapy on motor or non-motor domains.…”

Chiropractic management of essential tremor and migraine: a case report

“…1 It has also been discovered that cerebellar motor disturbances, cognitive disturbances, personality changes, hearing loss, and olfactory deficits are associated with ET. 1 Symptoms are usually seen in the arms, head, or voice with occasional involvement of the legs, chin, and trunk. 2 Essential tremor is often accompanied by a family history of similar tremors 2,3 and has also been linked to several genes.…”