Note 11 - Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

	Year Ended December 31,
	201 8		201 7		201 6
Stock options and ESPP awards
Research and development	$	21	$	37	$	62
Selling, general and administrative		48		122		321
Restricted stock awards
Research and development		-		12		116
Selling, general and administrative		-		17		143
Restricted stock units
Research and development		85		70		28
Selling, general and administrative		417		163		216
Stock appreciation rights
Research and Development		61		-		-
Selling, general and adminstrative		51		-		-
Total stock-based compensation	$	683	$	421	$	886

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Year Ended December 31,
	201 8		201 7			201 6
Risk-free interest rate		–		2.01	%		1.49	%
Expected dividend yield		–		None			None
Expected volatility factor		–		119.00	%		106.70	%
Expected option life (in years)		–		5.77			5.77
Weighted average grant date fair value	$	–	$	0.86		$	5.66

	December 31, 2018			Grant Date(1)
Risk-free interest rate		2.54	%		2.84	%
Expected dividend yield		–			–
Expected volatility factor		134.17	%		125.03	%
Expected option life (in years)		5.75			5.75
Weighted average grant date fair value	$	1.65		$	4.53

Share-based Compensation, Stock Options, Activity [Table Text Block]

						Weighted-
						Average
				Weighted-		Remaining
				Average		Contractual
	Number of			Exercise		Term		Aggregate
	Options			Price		(years)		Intrinsic Value
Options outstanding at December 31, 2017		2,346		$	2,103.20			$	-
Granted		–			–
Canceled or forfeited		(33	)		876
Exercised		-			-
Options outstanding at December 31, 2018		2,313		$	2,358.44		6.87	$	-
Options exercisable at December 31, 2018		1,922		$	2,545.98		6.61	$	-
Options vested and expected to vest at December 31, 2018		2,313		$	2,358.44		6.87	$	-

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

			Options Outstanding						Options Exercisable
							Weighted-						Weighted-
					Weighted-		Average				Weighted-		Average
Range of					Average		Remaining				Average		Remaining
Exercise			Number of		Exercise		Contractual Life		Number of		Exercise		Contractual Life
Prices			Options		Price		in Years		Options		Price		in Years
$0.00	to	$11,484		2,246	$	475		7.06		1,855	$	569		6.82
$11,485	to	$22,968		18	$	17,869		1.14		18	$	17,869		1.14
$45,936	to	$57,420		13	$	56,460		0.21		13	$	56,460		0.21
$57,421	to	$68,904		18	$	60,457		0.18		18	$	60,457		0.18
$68,905	to	$80,348		7		76,020		1.66		7		76,020		1.66
$91,872	to	$103,356		8	$	98,442		0.91		8	$	98,442		0.91
$103,357	to	$114,840		3	$	106,001		<.01		3	$	106,001		<.01
				2.313	$	2,097		6.88		1,922	$	2,517.03		6.61

Schedule of Nonvested Share Activity [Table Text Block]

				Weighted-
				Average
	Number of			Grant-Date
	Shares			Fair Value
Non-vested at December 31, 2017		155		$	876.00
Granted		290,300			3.45
Vested		(155	)		876.00
Canceled or forfeited		-			-
Non-vested at December 31, 2018		290,300		$	3.45