Pat. with essential tremor not response to propranolol and primidone .what is next management?

Essential Tremor: Dear patient please refer to the following mayo clinic website http://www.Mayoclinic.Com/health/essential-tremor/ds00367/dsection=treatments%2dand%2ddrugs.

Many: Propranolol can be incr to as much as 320 mg a day if hr and BP permit. Primidone can be increased to as much as 750 mg/day, limited initially by n, v, and ataxia (incoordination). Other drugs are: gabapentin, alprazolam, topiramate and finally, deep brain stimulation. Tremor that does not cause impairment or embarrassment does not require treatment.