Amantadine and cognitive flexibility: decision making in Parkinson’s patients with severe pathological gambling and other impulse control disorders

Figures & data

Figure 1 Psychological tasks.

Notes: (A) Detailed procedure of a risk-taking task. (B) Detailed procedure of the Stroop task and the emotional Stroop task.

Table 1 Patient demographics

	Group A PD-PG (n=10)	Group B PD-ICD (n=9)	Group C PD-CTR (n=14)
Age (years)/male sex	60.6±6.8/7	59.3±6.8/6	59.0±9.5/7
Education (years)	11.7±2.6	10.3±3.2	11.7±1.9
Disease duration (months)	28.2±12.3	29.0±8.5	27.2±8.4
UPDRS III	20.5±6.8	21.4±4.2	21.6±6.9
Hoehn/Yahr stage	1.9±0.2	1.7±−0.3	1.7±0.02
MMSE	28.5±2.1	28.4±1.9	28.6±2.0
SOGS	13±2.5	4±0.5	0.8±0.3
YBOCS	9.3±3.8	8.3±7.8	2.1±0.9
Quip-RS	37.5±15.1	51.0±11.1	5.00±3.5
L-dopa equivalent dose (mg)	294.5±123.1	283.3±132.9	307±96.3

Abbreviations: CTR, control; ICD, impulse control disorder; L-dopa, L-3,4-dihydroxyphenylalanine; MMSE, mini–mental state examination; PD, Parkinson’s disease; PG, pathological gambling; Quip-RS, Questionnaire for Impulsive-Compulsive Disorders in Parkinson’s Disease-Rating Scale; SOGS, South Oaks Gambling Screen; UPDRS III, unified Parkinson’s disease rating scale motor part; YBOCS, Yale–Brown obsessive compulsive scale.

Table 2 Within-subjects task results

Group	Condition	Time	Mean	SD	t-value	df	P-value
Risk taking task
PD-PG	Risk	T0	42.8	16.4
		T1	28.7	16.2	2.40	9	0.039
	No risk	T0	40.6	13.8
		T1	56.4	21.6	−2.67	9	0.025
PD-ICD	Risk	T0	46.3	5.6
		T1	40.2	12.3	1.46	8	0.181
	No risk	T0	40.7	5.7
		T1	49.7	18.2	−1.30	8	0.229
PD-CTR	Risk	T0	42.5	18.4
		T1	46.3	0.9	−0.84	13	0.413
	No risk	T0	43.9	16.6
		T1	52.4	1.8	−1.84	13	0.088
Stroop task
PD-PG	Congruent	T0	85.7	15.5
		T1	83.1	14.3	0.32	9	0.75
	Incongruent	T0	88.9	7.1
		T1	91.6	8.1	−0.80	9	0.442
PD-ICD	Congruent	T0	88.3	6.6
		T1	88.3	16.6	0.00	8	1
	Incongruent	T0	93.9	3.1
		T1	90	17.4	0.72	8	0.489
PD-CTR	Congruent	T0	85.7	15.5
		T1	81.4	21.4	1	13	0.33
	Incongruent	T0	84.3	14.2
		T1	82.8	14.1	1	13	0.33
Emotional stroop task
PD-PG	Negative	T0	65.6	7.3
		T1	68.8	3.7	−1.92	9	0.086
	Positive	T0	64	8
		T1	29.3	3.9	15.83	9	0.000
PD-ICD	Negative	T0	67.1	3.3
		T1	70.8	1.7	−2.78	8	0.023
	Positive	T0	70.7	2.8
		T1	40	1.9	25.03	8	0.000
PD-CTR	Negative	T0	64	10.2
		T1	66.8	6.5	−1.11	13	0.28
	Positive	T0	66	5.4
		T1	56.8	19.8	−1.12	13	0.28

Abbreviations: CTR, control; ICD, impulse control disorder; PD, Parkinson’s disease; PG, pathological gambling; SD, standard deviation; T0, before amantadine add-on medication; T1, after amantadine add-on medication; df, degrees of freedom.

Figure 2 Within-group results.

Notes: Graphs show percentage of risky and non-risky choices in risk-taking task, and accuracy in Stroop task and emotional Stroop task, respectively, before (0) and after (1) amantadine add-on therapy. Vertical bars indicate standard deviations. *P<0.05; **P<0.0001.
Abbreviations: CTR, control; ICD, impulse control disorder; PD, Parkinson’s disease; PG, pathological gambling; resp, response.