Comparison of tremor induced by valproate and lithium in bipolar disorder using a hand steadiness tester

Abstract

Background: Quantitative measurement of valproate and lithium induced tremor using hand steadiness tester and their comparison in bipolar disorder. Methods: 200 newly diagnosed patients of bipolar disorder were randomly allocated into two equal groups receiving lithium (300mg twice daily) and sodium valproate (500 mg twice daily) after they fulfilled the inclusion / exclusion criteria of the study. 87 patients from Lithium group and 93 from Valproate completed the study.  Hand Tremor was assessed quantitatively at 0, 6, 12, 18 and 24 weeks using hand steadiness tester. Anxiety level of the study subjects was assessed to be insignificant using a standardized anxiety scale.  Final data was assessed after 24 weeks by using Stat Calc and Z test. P value <0.05 was considered to be significant. Results: No significant difference was found in terms of the development and transition of tremor induced by valproate and lithium (p=0.22).  However more men developed tremor with lithium when compared with females (p<0.05) and the mean age of patients who developed tremor appeared to be significantly higher in lithium group (54.7±3.9) than valproate (39.6±5.1). Conclusions: Tremor of hands is a common side effect of lithium and valproate treatment. Timely, objective assessment of onset and extent of tremor has always remained a challenge to the clinicians. Hand Steadiness tester is a simple, portable, inexpensive, non-invasive instrument that can be used to ascertain the development and transition of tremor in a quantitative manner. This would guide the clinicians as when to intervene for better management of such tremors.