Mirtazapine in the treatment of essential tremor: an open-label, observer-blind study

Figures & data

Table 1 Primary, secondary, and key criteria in ET differential diagnosis

Primary criteria

– Bilateral action tremor of the hands and forearms (but no tremor while at rest) – Lack of other neurological signs, except the “gear-wheel” phenomenon – Isolated head tremor could be present, with no anomalous postures or dystonies

Secondary criteria

– Long period of time (> 3 years) – Family history – Reduction with intake of alcoholic beverages

“To be differentiated”

– Unilateral tremor, focal tremor, tremor of the legs, walking disorder, stiffness, bradykinesia, tremor at rest – Sudden or rapid appearance – Simultaneous therapy with tremor causing or tremor increasing drugs – Isolated head tremor with anomalous postures (bending or rotation)

Adapted from: Elble (2000).

Table 2 Tremor rating scale

	0	1	2	3	4
A – Resting tremor	absent	slight, intermittent, small amplitude, hardly disturbing, controlled by will	moderate, constant, amplitude is variable but less than 50 mm, disturbing to the subject, can be controlled by will	serious, constant, amplitude ranging from 50 to 100 mm, very disturbing for the subject, only temporarily suppressed by will	very serious, constant, over 100 mm amplitude, disabling, hardly controlled by will
B – Postural tremor (Rated with glass full to the brim)	absent	slight, intermittent, small amplitude, hardly disturbing, no spilling from glass	moderate, constant, variable amplitude but still slight, not very disturbing for the subject, intermittent and slight dripping from glass	serious, constant, average amplitude interferes with many activities, constant dripping from glass	very serious, constant, considerable amplitude, hindering activities, marked dripping from glass
C – Action tremor  C1: in alternating flexion/extension arm movements  C2: in reaching a target (index-nose test)	absent	slight, intermittent, small amplitude, hardly disturbing, controlled by will	moderate, constant, amplitude is variable but less than 50 mm, disturbing to the subject	serious, constant, amplitude ranging from 50 to 100 mm, interferes with many activities	very serious, constant, over 100 mm amplitude, hindering activities
D – Orthostatic tremor	absent	slight, intermittent, small amplitude	slight, constant, with variable oscillations	moderate, constant, average amplitude, can interfere with balance	serious, constant, with broad oscillations, can be disabling
E – Tremor of the head	absent	slight and intermittent	slight but constant, not disturbing	moderate, constant, interferes with some activities	serious, constant, interferes with most activities
F – Speech	normal	slight tremor of the voice, not steady, no difficulty in making oneself understood	slight tremor of the voice, constant, occasional difficulties in making oneself understood (rarely needs to repeat sentences)	moderate tremor of the voice, pronouncing words distinctly now and then, constant, a few incomprehensible sentences need to be repeated	serious tremor of the voice, articulating words and not very understandable
G – Writing	normal	slightly impaired, but legible	moderately impaired, but every word is legible	seriously impaired, a few words illegible	illegible
H – Overall subjective disability	absent	slight, variable	slight, constant	moderate	serious

Adapted from Deuschl (1987).

Table 3 Clinical evaluation of essential tremor (ET) before and after 1 month of treatment with mirtazapine (30 mg/daily) (number of patients = 27)

	Before treatment	After treatment	p
Resting tremor	–	–	–
Postural tremor	2.11 ± 0.42a	1.19 ± 0.56	< 0.01
Action tremor
C1: in alternating flexion/extension arm movements	1.41 ± 0.64	0.74 ± 0.71	< 0.01
C2: in reaching a target (index/nose test)	1.56 ± 0.75	0.89 ± 0.58	< 0.01
Orthostatic tremor	–	–	–
Tremor of the head	0.96 ± 1.01	0.48 ± 0.70	< 0.01
Speech	1.07 ± 0.96	0.59 ± 0.69	< 0.01
Writing	1.67 ± 0.68	0.89 ± 0.70	< 0.01
Overall subjective disability	2.15 ± 0.53	1.04 ± 0.65	< 0.01

a Values are means ± standard deviation of mean.

ElbleRJ2000Diagnostic criteria for essential tremor and differential diagnosisNeurology54Suppl 4S2610854344

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DeuschlGLuckingCHSchenckE1987Essential tremor: electro-physiological and pharmacological evidence for a subdivisionJ Neurol Neurosurg Psychiatry501435413694203

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