Augmentation: Criteria, Prevalence, and Differential Diagnosis

Preamble
Augmentation is a worsening of RLS symptom severity experienced by patients undergoing treatment for RLS. The RLS symptoms in general are more severe than those experienced at baseline
A. Basic features (all of which need to be met):
   1. The increase in symptom severity was experienced on five out of seven days during the previous week
   2. The increase in symptom severity is not accounted for by other factors such as a change in medical status, lifestyle, or the natural progression of the disorder
   3. It is assumed that there has been a prior positive response to treatment
In addition, either B or C or both have to be met
B. Persisting (although not immediate) paradoxical response to treatment: RLS symptom severity increases some time after a dose increase and improves some time after a dose decrease
OR
C. Earlier onset of symptoms:
   1. An earlier onset by at least four hours
OR
   2. An earlier onset (between two and four hours) occurs with one of the following compared to symptom status before treatment
      a. Shorter latency to symptoms when at rest
      b. Spreading of symptoms to other body parts
      c. Intensity of symptoms is greater (or increase in periodic limb movements [PLM] if measured by polysomnography [PSG] or the suggested immobilization test [SIT])
      d. Duration of relief from treatment is shorter
Augmentation requires criteria A + B, A + C, or A + B + C to be met
Several studies have reported a correlation between the presence of augmentation during dopaminergic treatment with the severity of RLS/WED symptoms at baseline and with a higher medication dosage, but not with age or gender [810]. Clinical experience shows that when severe, augmentation can result in a weakening or even a loss of essential RLS/WED features. Thus, symptoms are no longer reduced during inactivity or movement, and there is virtually no circadian pattern. The clinical picture obtained during dopaminergic augmentation resembles the one obtained in severe RLS/WED, with severe symptoms occurring most of the day and affecting all limbs. None of the clinical features of dopaminergic augmentation are specific to this condition or can be differentiated from RLS/WED itself. In fact, RLS/WED augmentation reflects a worsening of RLS/WED severity during dopaminergic treatment. Recently published recommendations on the management of augmentation from the International RLS Study Group (IRLSSG) identified a number of screening questions that may be used in clinical practice to identify possible augmentation, but these have yet to be validated [11].

Incidence of Augmentation Under Dopaminergic Agents

Dopaminergic augmentation is very common and mostly unidentified in everyday clinical practice. A community survey performed on 266 RLS/WED patients being treated by primary care physicians or neurologists in the USA, whose medical records were reviewed by independent experts, showed some degree of augmentation in 75% of patients (20% with definite augmentation and 55% had partial symptoms of augmentation) [12].
A number of studies claim to have evaluated the incidence of augmentation for different drugs either prospectively or retrospectively (See Table 12.2). However, several issues make it difficult to ascertain correct incident rates for the different treatments for RLS/WED: Firstly, as mentioned above, there was no operational definition for augmentation before 2002. Secondly, the estimation of augmentation rates has been performed retrospectively, using different diagnostic criteria, and frequently based on the evaluation of clinical cases. Studies were not specifically designed to measure augmentation and frequently lacked specific information on augmentation. Third, trials were frequently not long enough for augmentation to manifest: It is a long-term consequence of treatment, and therefore, trials need to be longer than 6 months for augmentation to be seen. Finally, there is a lack of comparative trials with one single exception [4].
Table 12.2
Incidences of augmentation with dopaminergic RLS/WED therapies (Ref taken from [20])
Study
Design
Duration
Sample size
Assessment
Incidence of augmentation
Levodopa
Allen 1996 [5]
Prospective case series
N/A
30
Increase in appearance and severity of RLS/WED symptoms
73.3% (22/30 patients)
Trenkwalder 2007 [21]
Double-blind, randomized, active-controlled (cabergoline) trial
30 weeks
Levodopa: 183
Cabergoline: 178
ASRS ≥ 1
Augmentation defined according to NIH criteria
Augmentation (ASRS ≥ 1)
Levodopa: 40.4%
Cabergoline: 21.1%
Discontinuations due to augmentation
Levodopa: 9.8% (18/183 patients)
Cabergoline: 4.0% (7/178 patients)
Hogl 2010 [22]
Open-label trial
6 months
60
Augmentation diagnosed by two experts using established criteria. Changes in ASRS, IRLS, and CGI were analyzed
Augmentation: 60% (36/60 patients)
Discontinuations due to augmentation: 11.7% (7/60 patients)
Rotigotine
Trenkwalder 2008 [23]
Double-blind, randomized, placebo-controlled trial
6 months
Rotigotine: 341
Placebo: 117
ASRS (4-item version)
No signs of augmentation noted
Hening 2010 [24]
Double-blind, randomized, placebo-controlled trial
6 months
Rotigotine: 405
Placebo: 100
ASRS (4-item version)
Retrospective analysis of study data by an expert panel using the MPI criteria
Clinically relevant augmentation: 1.5% (6/404 patients) on rotigotine
1% (1/100 patients) on placebo
Oertel 2011 [25]
Open-label, continuation of double-blind, randomized, placebo-controlled trial
5 years
295
ASRS
Retrospective analysis of study data by an expert panel using the MPI criteria
Clinically significant augmentation: 5% (15/295 patients) on EMA-approved dosea
Benes 2012 [26]
Retrospective assessment of two double-blind studies [24, 27] and their respective open-label extensions
DB: 6 months
OL: 12 months
DB: rotigotine, 745;
placebo, 214.
OL: 620
Expert review of study data (IRLS, RLS-6, CGI-1, ASRS) using the MPI criteria
Clinically relevant augmentation
DB: 1.5% (11/745 patients) on rotigotine; 0.5% (1/214) patients on placebo
OL: 2.9% (18/620 patients)
Cano 2013 [28]
Retrospective chart review
12 years
138
(112 received ≥1 RLS/WED medication)
Not specified
Rotigotine: 0% Clonazepam: 37.1%
Ropinirole: 40.4%
Inoue 2013 [29]
Open-label continuation of a double-blind trial
1 year
185
ASRS ≥ 5 used to identify patients with possible augmentation. These patients were then assessed by expert panel using the MPI criteria
Clinically significant augmentation: 2.7% (5/185 patients)
Miranda 2013 [30]
Switching study
18 months
10
None described
None reported
Ropinirole
Montplaisir 2006 [31]
Single-blind phase followed by double-blind treatment
SB: 24 weeks
DB: 12 weeks
202
Augmentation recorded as an adverse event (AE)
Possible augmentation
Ropinirole: 1.5% (3/202 patients)
Garcia-Borreguero 2007 [9]
Open-label, continuation of double-blind, randomized, placebo-controlled trial
52 weeks
310
Retrospective assessment of AEs
9.1% (28/309) had AEs coded to RLS
2.3% (7/30) had AEs recorded as augmentationb
Garcia-Borreguero 2012 [32]
Double-blind, randomized, placebo-controlled trial followed by open-label continuation
DB: 26 weeks
OL: 40 weeks
DB: 404
OL: 269
ASRS
Potential cases prospectively identified by a structured diagnostic interview and by reporting of AEs, and then evaluated by an expert panel based on the NIH criteria
Clinically significant augmentation
DB: 3% (5/197) patients on rotigotine; 0.48% (1/207) patients on placebo
OL: 2% (5/269 patients)c
Pramipexole
Montplaisir 2000 [33]
Open-label continuation of double-blind study
Mean: 7.8 months
7
Not specified
None reported
Ferini-Strambi 2002 [16]
Open-label trial
≥6 months
60
Not specified
8.3% (5/60 patients)
Silber 2003 [34]
Retrospective chart review
30 months
60
New development or increase in severity, duration, or anatomic distribution of RLS/WED earlier in the day than the time a medication for RLS/WED was taken
33% (16/49 patients)
Winkelman 2004 [15]
Retrospective chart review
Average of 21.2 ± 11.4 months; range: 6–60 months
59
Earlier RLS/WED symptom appearance (≥5 times/week) requiring earlier administration of medications (>2 h)
Extension of symptoms beyond legs
32% (19/59) of patients
Trenkwalder 2006 [35]
Double-blind, randomized, placebo-controlled withdrawal study
3 months (following 6 months OL treatment)
Pramipexole: 78
Placebo: 72
ASRS
None reported
Inoue 2010 [36]
Open-label, continuation of double-blind, randomized, placebo-controlled trial
52 weeks
141 (Japanese pts)
Patient diary
Defined as symptom appearance ≥ 2 h earlier than usual for ≥ 5 days/week

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Sep 23, 2017 | Posted by in NEUROLOGY | Comments Off on Augmentation: Criteria, Prevalence, and Differential Diagnosis

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