Table 1.

Summary of clinical and MRI data from the different reports (EDTA: ethylenediaminetetraacetic acid, GP: globus pallidus, GPi: internal part of globus pallidus, NCh: head of caudate nucleus, PAS: para-aminosalicylic acid, SI: signal intensity, SN: substantia nigra, SNr: reticular part of substantia nigra, STN: subthalamic nucleus, y: years).

Publication	No. of the subjects	Age (y)	Time to the symptoms	Initial symptoms	MRI findings	Treatment	Outcome
Levin 2005 [33]	21	15–36 (21 ± 5.8)	3–14 (6.8 ± 4.9) months	Disorders of speech (33%) and gait (29%), fatigue (29%), bradykinesia (14%), affective symptoms (19%)	T1 bilateral symmetric SI in GPi, SNr—18 (86%); no correlation with duration of usage, dosage nor severity of the symptoms	EDTA, l-dopa, clonazepam, amantadine	Spontaneous regression of the symptoms—29%, worsening—33% even after 4 y abstinence
Sikk et al. 2007, 2010 [14, 34]	4 (case reports)	24–42	6 months–8 y	Gait disorder—2, hypophonia—2	T1 SI increase in GP, putamen, NCh—2 cases; decrease of SI in the same areas—1	Not reported	Initial improvement then stable—1, stable still using—1, slow progression of the symptoms—2
De Bie et al. 2007 [19]	1 (case report)	36	Not exactly reported, possibly 4–16 months	Decrease of libido; sleepiness, slowness	Symmetric SI increase in GP, SN dentate nucleus, and pontine tegmentum	Pramipexole, selegiline, l-dopa	No improvement
Sanotsky et al. 2007 [15]	6 (case reports)	23–45	2 months–1 y	Speech and gait disorder—1, plus bradyphrenia or depression—2, slowness—2, hyperthermia—1	Striking bilateral SI increase of lentiform nucleus, SN, dentate nucleus	EDTA, cerebrolysin, amantadine, l-dopa	Mild to moderate improvement—4, no improvement—2
Meral et al. 2007 [35]	2 (case reports)	21 and 32	Unknown, 4 months	Bradykinesia, gait and speech disorders	Bilateral SI increase in GP. After withdrawal of injections, improvement of MRI in case 2	Not reported	No improvement
Stepens et al. 2008 [17]	23	37.5 ± 6.5	5.8 ± 4.5 y	Gait disturbance—20 (87%), hypophonia—3 (13%)	T1 SI increase in GP—all 10 active users, in SN—9; former users had lesser degrees of change (SI increase in GP—11, SN—2, anterior midbrain—3)	L-dopa in 3 patients	No substantial improvement in 13 subjects after withdrawal for 2–6 y
Selikhova et al. 2008 [16]	13	18–46 (29.9)	8.5 ± 3.2 months	Loss of balance—7, slurred speech—4, mood disorders—2	T1 SI increase mostly in GPi,—all; other frequently involved structures—STN, SNr, putamen	L-dopa, amantadine, EDTA,	Significant residual deficit; delayed progression in some cases
Colosimo and Guidi 2009 [18]	1 (case report)	28	2 y	Gait and speech disturbance, mental slowness, generalized fatigue	Repeated MRI normal	Not reported	Some deterioration of motor signs
Yildirim et al. 2009 [36]	1 (case report)	29	9.5 y since start of abuse, 5 y abstinence	Gate disturbance, mood disorders	Normal	Piracetam, carbamazepine, fluoxetine, l-dopa	Gradual worsening over time
Varlibas et al. 2009 [37]	3 (case reports)	15–19	2–6 y	Postural instability, face and limb dystonias, tremor, dysphonia, dysarthria, bradykinesia	Bilateral symmetric SI increase in dentate nucleus, white matter of cerebellum, GP and putamen	EDTA, PAS, l-dopa	No improvement