Selected Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other Current Assets [Line Items]
Prepaid insurances	$ 419	$ 351
Prepaid consulting, subscriptions and other expenses	132	290
Prepaid conferences, travel	42	94
Prepaid clinical research organizations	0	46
Clinical consulting services refund receivable	0	46
Total	$ 593	$ 827

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