Comparison of Botulinum Toxin Injections in Forearm FLexor Plus EXtensor Muscles vs. Flexor Muscles Alone for Treatment of Essential Hand Tremor(FLEX-D ET)

Comparison of Botulinum Toxin Injections in Forearm FLexor Plus EXtensor Muscles Versus Flexor Muscles Alone for the Treatment of Essential Hand Tremor (FLEX-D ET)

To compare the efficacy of botulinum toxin (BoNT) injections in forearm flexors plus extensor muscles versus flexors alone for the treatment of essential hand tremor (ET).

The investigators propose a pilot, single center, double blind, randomized, parallel, placebo controlled trial comparing 2 (BoNT) injection patterns for treatment of moderate to severe essential tremor. The investigators will recruit 20 patients with (ET).

Inclusion Criteria:

1. Age 18 and over, male or female patient with (ET) involving at least their dominant hand, as diagnosed by a movement disorders neurologist.
2. Having bothersome hand tremor in dominant hand with a hand TRS ≥2
3. On stable medications during last 30 days prior to enrollment.

Exclusion Criteria:

1. Presence of secondary causes of tremor, such as dystonia and parkinsonism
2. Any contraindication to botulinum toxin injections (e.g. motor neuron disease, neuromuscular junction disease, etc.)
3. History of surgical treatment for (ET).
4. Dementia as defined by DSM-V criteria
5. Patients with suboptimally treated depression and significant depressive symptoms as defined by a PHQ-9 score of ≥15 (PHQ-9 scores 1-4 Minimal depression; 5-9 Mild depression; 10-14 Moderate depression; 15-19 Moderately severe depression; 20-27 Severe depression). Antidepressant medications, prescribed for depression or anxiety, will be allowed if the patient has been on a stable dose for at least 30 days.
6. Patients with suboptimally treated anxiety and significant anxiety symptoms as defined by a GAD-7 score of ≥15 (GAD-7 scores 0-4: minimal anxiety; 5-9: mild anxiety; 10-14: moderate anxiety; 15-21: severe anxiety). Anti-anxiety medications, prescribed for anxiety, will be allowed if the patient has been on a stable dose for at least 30 days.
7. Significant renal, hepatic, cardiac and thyroid disease