Therapeutic effect of an inhaled levodopa dry powder formulation on off episodes in patients with Parkinson's disease.

Background: Limited treatment options with a rapid onset of action are available to treat off episodes in Parkinson's disease (PD) patients. Therefore, the development of rapid onset formulations, for instance with levodopa, is warranted, which was the reason to investigate an inhalable formulation of levodopa. Objectives: The primary objective was to determine the duration until maximum effect is reached of inhaled levodopa on the improvement of motor function of PD patients. The secondary objective was to compare the time until maximal effect and the maximal effect of inhaled levodopa versus oral levodopa. Design: Open-label randomized two-way one-period crossover trial. Methods: Nine PD patients in the 'off state' received one dose of inhaled levodopa (90 mg) from Cyclops® and one dose of levodopa orodispersible tablet (100 mg) on two consecutive days in a randomized order. A timed tapping test, Timed Up and Go test (TUG test) and Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) III score were performed pre-dose and on set time points up to 90 min post-dose as measure for motor function. In addition, blood samples were taken for a pharmacokinetic evaluation (T max, C max and area under the concentration time curve (AUC) 0-3 h). Results: The maximal effect of inhaled levodopa was reached at 30 min (tapping test), at 75 min (TUG test) and at 60 min (UPDRS III). The positive effect on the UPDRS was statistically significant within 20 min after inhalation. After oral administration, C max and AUC 0-3 h were found to be significant higher (p = 0.028 and p = 0.028, respectively) than after pulmonary administration. T max was achieved significantly (p = 0.028) faster after inhalation. The motor function examinations showed a similar maximum clinical improvement after pulmonary and oral administration and although not significant, inhaled levodopa results in a shorter median duration to maximum clinical effect for the TUG and timed finger-tapping test compared with oral administration (TUG: inhalation 55.0 and oral 67.5 min, timed finger-tapping test: inhalation 35.0 and oral 57.5 min). After the levodopa inhalation, there were no adverse events observed and no significant differences found in long-function parameters. Conclusion: Inhaled levodopa from Cyclops® shows promising data as a rescue therapy for PD patients with off episodes, not responsive to the current oral therapies. Trial registration: The study protocol was approved by the local ethics board 'Regionale toetsingscommissie patiëntgebonden onderzoek' (RTPO) in Leeuwarden, The Netherlands (approval number RTPO1019). The study was registered in in the Dutch trial register (LTR) with identification number NL6876. From 5 March 2024 on, the research data on onderzoekmetmensen.nl are known as 'Overview of Medical Research in the Netherlands' (OMON). This means the use of the name LTR has thus been dropped. Now, it is registered in the OMON with the same identification number (NL6876, Effectiveness of inhaled levodopa in PD | Research with human participants (onderzoekmetmensen.nl)). All patients provided written informed consent.

Replenishing Cation-π Interactions for the Fabrication of Mesoporous Levodopa Nanoformulations for Parkinson Remission.

Directly assembling drugs into mesoporous nanoformulations will be greatly favored due to the combination of enhanced drug delivery efficiency and mesostructure-enabled nanobio interactions. However, such an approach is hindered due to the lack of understanding of polymer nanoparticles' formation mechanism, especially the relationship between polymerization, self-assembly, and the nucleation process. Here, by investigating the levodopa and dopamine polymerization process, we identify π-cation interaction as pivotal in the self-assembly and nucleation control of dopa molecules. Thus, through manipulation of the π-cation interaction, we present the direct assembly of a commercial drug, levodopa, into mesoporous nanoformulations. The synthesized nanospheres, approximately 200 nm in diameter, exhibit uniform mesopores of around 8 nm. These nanoformulations, abundant in mesopores, enhance chiral phenylalanine interaction with α-synuclein (Syn), curbing aggregation, safeguarding neurons, and alleviating Parkinson's pathology. When combating α-synuclein, the nanoformulation achieved ∼100% inhibition of protein aggregation and sustained neuron viability up to 300%. We believe that this study may advance mesoscale self-assembly knowledge, guiding future nanopharmaceutical developments.

Rate of motor progression in Parkinson's disease: a systematic review and meta-analysis.

Background: The search for neuroprotective treatments for Parkinson's disease (PD) still relies largely on motor disability scales. A limitation of these tools is the strong influence of symptomatic dopaminergic treatment effects. Drawing on a wealth of published information, we conducted a systematic review and meta-analysis of motor progression in PD and its relationships with dopaminergic therapy. Methods: We searched Medline, Embase, and Central to identify 84 publications with adequate serial motor scores to calculate progression, expressed as an increase in the percentage of maximum disability. Results: A random-effects model showed motor progression at 2.0% p.a. (95% CI 1.7-2.4%). There were no significant differences by baseline age, sample size, or observation period. However, untreated patients, in 8 publications, progressed at 4.5% p.a. compared to 1.6% p.a. in 76 studies containing individuals on dopaminergic drugs (p = 0.0004, q = 0.003). This was supported by research on phenoconversion in prodromal PD, where motor progression exceeded 5% p.a. in the 2 years before diagnosis. Starting levodopa improved pre-treatment disability by 40.3 ± 15.2%. Practically defined off state measurements increase faster than on scores by a modest degree (p = 0.05). Conclusion: This survey suggests that accurate long-term measurements of motor progression to assess disease-modifying therapies can be conducted despite the sequential commencement of dopaminergic drugs and sample attrition over time. While study designs involving prodromal or untreated PD avoid confounding effects of symptomatic treatment, different assumptions about motor progression may be needed. A defined off state with the levodopa test dose method maximizes information about the medication cycle once dopaminergic therapy has begun.

Greenness and whiteness appraisal for bioanalysis of quetiapine, levodopa and carbidopa in spiked human plasma by high performance thin layer chromatography.

A sustainable HPTLC-densitometric method was developed for quantitative determination of Quetiapine (QUET), Levodopa (LD) and Carbidopa (CD) in presence of Dopamine (DOP) as an internal standard. This applicable technique was achieved by spiking human plasma and extraction was performed using the protein precipitation approach. The mobile phase used was acetone, dichloromethane, n-butanol, glacial acetic acid and water (3: 2.5: 2: 2: 1.75, by volume). Method validation was done according to US-FDA guidelines and was able to quantify Quetiapine, Levodopa and Carbidopa in the ranges of 100-4000, 200-8000 and 30-1300 ng/mL, respectively. Bioanalytical method validation parameters were assessed for the studied drugs. Finally, the analytical suggested methodology was evaluated using various green and white analytical chemistry metrics and other tools, such as the green solvent selection tool, analytical eco-scale, green analytical procedure index, analytical greenness metric approach and the red-green-blue algorithm tool. The results revealed that the applied analytical method had a minor impact on the environment and is a relatively greener option than other previously reported chromatographic methods.

Implication of nutrition in severity of symptoms and treatments in quality of life in Parkinson's disease: a systematic review.

Parkinson's disease (PD) is characterized by motor and non-motor symptoms. Nutritional alterations are one of the non-motor symptoms that most influence the quality of life (QoL) in PD. Objective: Therefore, this review aims to evaluate whether nutritional alterations are related either to the severity of motor and non-motor symptoms through the gut-brain axis or to the different treatments for PD and whether all of this, in turn, impacts the QoL of patients. Methods: A systematic review was carried out in MEDLINE and EMBASE databases, and Mendeley from 2000 to June 2024, searching for articles related to nutritional alterations in PD that alter patients' QoL. A total of 14 articles (2,187 participants) of 924 records were included. Results: Among the 14 studies examined, two investigated the relationship between nutritional status and QoL in patients with PD. Poor nutritional status was associated with lower QoL scores. Four studies explored the connection between nutritional status and its impact on both motor and non-motor symptoms (psychiatric disturbances, cognitive impairment, and fatigue), revealing a link between nutritional status, activities of daily living, and the severity of motor symptoms. Three studies identified changes in body weight associated with the severity of symptoms related to mobility issues in PD patients. Three studies investigated the relationship between different PD treatments and their interaction with changes in weight and energy metabolism, highlighting that weight loss in the early stages of PD needs adequate monitoring of different treatments, as well as the interaction between the central and peripheral nervous systems in regulating these processes. Finally, two studies investigated how gastrointestinal alterations and changes in the microbiota were related to cognitive status, thus identifying them as risk factors and early signs of PD. Discussion: The systematic review highlighted the significant relationship between nutritional status and QoL in patients with PD, as well as how the PD treatments influenced their weight. An association was also observed in the gut-brain axis, where adequate nutritional status influenced the balance of intestinal microbiota, slowing cognitive decline, improving activities of daily living, and the QoL of PD patients. It is confirmed that the nutritional status of patients influenced both motor and non-motor symptoms of the disease, and therefore their QoL.

Risk factors for 3-year mortality in selected patients with Parkinson's disease from a Romanian cohort.

This study aimed to identify and analyze factors associated with a higher risk of 3-year mortality in patients with Parkinson's disease (PD) within a Romanian cohort, focusing on individuals with more advanced disease stages as indicated by the Hoehn and Yahr scale. We conducted a cross-sectional observational study on 42 patients with PD treated at the Neurology Clinic I, Cluj-Napoca County Emergency Clinical Hospital, between October 2019 and January 2021. All participants were at stages 2.5 or 3 on the Hoehn and Yahr scale at baseline. Various clinical, neuropsychological, and neurophysiological assessments were performed, including evaluations for motor and non-motor symptoms such as anhedonia (via the Snaith-Hamilton Pleasure Scale - SHAPS) and cognitive impairment. The use of antiparkinsonian medications and antidepressants was also recorded. Factors associated with higher mortality risk included a higher anhedonia score (SHAPS > 34; P = 0.03), higher levodopa doses (cutoff = 937.5 mg; P = 0.001), and the administration of mirtazapine (P = 0.04). These findings indicate that non-motor symptoms like anhedonia, along with higher medication doses and specific treatments, play a significant role in influencing mortality risk in advanced PD. This study highlights the multifaceted nature of mortality risk in patients with PD, particularly emphasizing the role of non-motor symptoms and pharmacological treatment. Tailored therapeutic strategies, including closer monitoring of anhedonia and careful management of medication dosages, may be essential in reducing mortality and improving patient outcomes in advanced stages of PD.

A rare patient with Parkinson's disease presenting with isolated progressive micrographia.

Although handwriting impairment is a frequent sign of Parkinson's disease (PD), its significance in the evaluation processes of these patients may be overlooked among physicians. Therefore, we would like to report an illustrative patient who presented with isolated micrographia initially; but received the diagnosis of PD in the follow-up.

Targeting the Sirtuin-1/PPAR-Gamma Axis, RAGE/HMGB1/NF-κB Signaling, and the Mitochondrial Functions by Canagliflozin Augments the Protective Effects of Levodopa/Carbidopa in Rotenone-Induced Parkinson's Disease.

Background and Objectives: Parkinson's disease (PD) is a pathological state characterized by a combined set of abnormal movements including slow motion, resting tremors, profound stiffness of skeletal muscles, or obvious abnormalities in posture and gait, together with significant behavioral changes. Until now, no single therapeutic modality was able to provide a complete cure for PD. This work was a trial to assess the immunomodulatory effects of canagliflozin with or without levodopa/carbidopa on rotenone-induced parkinsonism in Balb/c mice. Materials and Methods: In a mouse model of PD, the effect of canagliflozin with or without levodopa/carbidopa was assessed at the behavioral, biochemical, and histopathological levels. Results: The combination of levodopa/carbidopa and canagliflozin significantly mitigated the changes induced by rotenone administration regarding the behavioral tests, striatal dopamine, antioxidant status, Nrf2 content, SIRT-1/PPAR-gamma axis, RAGE/HMGB1/NF-κB signaling, and mitochondrial dysfunction; abrogated the neuroinflammatory responses, and alleviated the histomorphologic changes induced by rotenone administration relative to the groups that received either levodopa/carbidopa or canagliflozin alone. Conclusions: Canagliflozin may represent a new adjuvant therapeutic agent that may add value to the combatting effects of levodopa/carbidopa against the pathological effects of PD.

A 4-Year Follow-Up of Levodopa-Entacapone-Carbidopa Intestinal Gel Treatment in Parkinson's Disease.

BACKGROUND: Levodopa-entacapone-carbidopa intestinal gel (LECIG) infusion was introduced to the Swedish market in 2019 for Parkinson's disease (PD) with motor fluctuations. Long-term data are lacking. OBJECTIVES: To study long-term data on LECIG treatment. METHODS: A retrospective analysis of the first 24 patients receiving LECIG in Sweden from 2019 to 2023. RESULTS: Five of 24 (21%) patients discontinued LECIG because of side effects, mostly diarrhea. Eight of the 24 (33%) patients died while receiving LECIG. Eleven of 24 (46%) patients were still on LECIG. Median (range) for disease and treatment duration was 19 (9-30) and 3.6 (3.1-4.0) years, respectively, whereas health-related quality of life scales showed median (interquartile range; n) Parkinson's Disease Questionnaire 8-item summary index scores of 38 (4; n = 7), EuroQol 5D scores of 0.59 (0.17; n = 7), and EQ-5D visual analogue scale scores of 65 (10; n = 7). CONCLUSIONS: LECIG infusion is a viable treatment option for PD patients with motor fluctuations, for up to 4 years in our cohort.

The Overtreatment Trap: Navigating Dopamine Dysregulation Syndrome in Parkinson's Disease.

Dopamine dysregulation syndrome (DDS) is a rare but significant complication of Parkinson's disease (PD), affecting approximately 3-4% of patients on long-term dopamine replacement therapy (DRT). It is characterized by an addictive pattern of DRT use that exceeds the necessary dosages for managing motor symptoms. Patients may engage in self-medication, escalating their DRT doses beyond prescribed limits, and strongly resist attempts to reduce medication. This syndrome often leads to impulsive behaviors, severe dyskinesia, and notable disruptions in social and occupational functioning. DDS is associated with a range of neuropsychiatric symptoms, including punding behaviors, hallucinations, and delusions. The management of DDS presents significant challenges, requiring a delicate balance between adequate symptom control and preventing medication overuse. We present a case of a 68-year-old woman with DDS, highlighting her symptoms and the tailored management strategies we employed to address this challenging condition.

Acute Levodopa Challenge in Atypical Parkinsonism: Comprehensive Analysis of Individual Motor Responses.

The acute levodopa challenge is widely used to distinguish Parkinson's disease (PD) from atypical parkinsonian syndromes (APSs) such as multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). In APSs, very few patients present a clinically relevant response to levodopa. The aim of this study was to determine whether patients with atypical parkinsonism benefit from levodopa in any aspect of their multiple motor deficits despite the generally poor response. This retrospective study analyzed individual motor responses to the acute levodopa challenge using the MDS-UPDRS III in 47 PSP, 26 MSA, and 71 PD patients at Hannover Medical School. Despite the generally poor levodopa response in both PSP and MSA patients, bradykinesia and rigidity were the symptoms most notably affected by levodopa in PSP patients, while MSA patients experienced significant improvements in bradykinesia and action tremor. These findings underscore the variability in levodopa response among PSP and MSA patients and highlight the need for personalized treatment approaches in atypical parkinsonism.

Trends on Novel Targets and Nanotechnology-Based Drug Delivery System in the Treatment of Parkinson's disease: Recent Advancement in Drug Development.

Parkinson's disease (PD) is a neurodegenerative disease (ND) that affects many people. However, there remains no cure for PD and difficulties exist with conventional medicines. There has been a lot of discussion about using nanotechnology to increase the bioavailability of smallmolecule drugs to target cells in recent years. It is possible that PD treatment might become far more effective and have fewer side effects if medication delivery mechanisms were to be improved. Potential alternatives to pharmacological therapy for molecular imaging and treatment of PD may lie in abnormal proteins such as parkin, α-synuclein, leucine-rich repeat serine and threonine protein kinase 2. Published research has demonstrated encouraging outcomes when nanomedicine-based approaches are used to address the challenges of PD therapy. So, to address the present difficulties of antiparkinsonian treatment, this review outlines the key issues and limitations of antiparkinsonian medications, new therapeutic strategies, and the breadth of delivery based on nanomedicine. This review covers a wide range of subjects, including drug distribution in the brain, the efficacy of drug-loaded nano-carriers in crossing the blood-brain barrier, and their release profiles. In PD, the nano-carriers are also used. Novel techniques of pharmaceutical delivery are currently made possible by vesicular carriers, which eliminate the requirement to cross the blood-brain barrier (BBB).

Molecular Variability in Levodopa Absorption and Clinical Implications for the Management of Parkinson's Disease.

Levodopa is the most widely used medication for the symptomatic treatment of Parkinson's disease and, despite being an "old" drug, is still considered the gold standard for offering symptomatic relief. The pharmacokinetic and pharmacodynamics of levodopa have been studied extensively. Our review explores the molecular mechanisms that affect the absorption of this drug, focusing on the large intra- and interindividual variability of absorption that is commonly encountered in daily clinical practice, and on the interaction with other medications. In addition, we will explore the clinical implications of levodopa absorption variability and address current and future strategies for researchers and clinicians.

Winding Back the Clock on Advanced Therapies: It's Time to Get Smart.

Our language affects patients' perceptions of therapies. In Parkinson's disease, emergent response fluctuations and dyskinesias typically trigger conversations around commencing an "Advanced Therapy" which carries notions of Advanced Disease. The patient, resolute in their commitment to fighting the disease, is misled. Chasing reassurance that their disease has not yet progressed considerably; they may therefore resist a potentially life-changing therapy. Instead, we should offer a "Smart Therapy". This term more accurately and positively describes therapies on offer that stabilize response fluctuations and improve quality of life, without a focus on the negative connotations of progression to more advanced disease.

The language we use with our patients affects their perception of a therapy on offer and their willingness to take it up. In Parkinson's disease when motor response fluctuations and dyskinesias become extremely challenging and disabling for patients despite medication optimization, it might prompt conversations with the patient in appropriate circumstances about offering an "Advanced Therapy" such as deep brain stimulation surgery or continuous infusion pumps. However, from the patient's perspective, putting up a steadfast fight against their disease, this label carries unwanted and misleading connotations of Advanced Disease. This can lead to hesitation from taking up these potentially life-changing therapies. Therefore, in this Commentary we propose a rebranding in line with other modern technology like smart phones and smart homes, emphasizing the positive and personalized features of these therapies, and focusing on the goal of stabilizing symptoms and improving quality of life. We should offer patients "Smart Therapies". It's time to Get Smart!

Associations between Constipation and Use of Levodopa with Nutritional Status, Polypharmacy, and Stage of Parkinson's Disease.

INTRODUCTION: Parkinson's disease (PD) is a highly prevalent disease characterized by motor and non-motor symptoms; the latter include constipation, which is considered a prodromal symptom. On the other hand, sarcopenia, polypharmacy, and malnutrition due to deficits are common in PD and lead to poorer health and quality of life. OBJECTIVE: to associate constipation and use of levodopa with nutritional status, sarcopenia, duration and stage of the disease, and polypharmacy in individuals with PD. MATERIALS AND METHODS: analytical cross-sectional observational study where an online survey was applied to 161 people suffering from PD. RESULTS: a significant association is observed between constipation and BMI (p = 0.022), as well as between the use of levodopa with BMI (p = 0.049) and polypharmacy (p = 0.046). On the other hand, there is a relationship between the average time of PD diagnosis and constipation (p = 0.0047). Finally, there is a relationship between SARC-F score applied to those over 60 years of age (p = 0.0446) and the use of levodopa. Having sarcopenia, being overweight, and having had the disease for less than five years is associated with a higher probability of experiencing constipation, according to the logistic regression analysis (p > 0.005). CONCLUSION: nutritional assessment and subsequent follow-up is of vital importance to avoid complications that could be associated with levodopa use, constipation, and sarcopenia.

Instrumented timed up and go test and machine learning-based levodopa response evaluation: a pilot study.

BACKGROUND: The acute levodopa challenge test (ALCT) is a universal method for evaluating levodopa response (LR). Assessment of Movement Disorder Society's Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III) is a key step in ALCT, which is some extent subjective and inconvenience. METHODS: This study developed a machine learning method based on instrumented Timed Up and Go (iTUG) test to evaluate the patients' response to levodopa and compared it with classic ALCT. Forty-two patients with parkinsonism were recruited and administered with levodopa. MDS-UPDRS III and the iTUG were conducted in both OFF-and ON-medication state. Kinematic parameters, signal time and frequency domain features were extracted from sensor data. Two XGBoost models, levodopa response regression (LRR) model and motor symptom evaluation (MSE) model, were trained to predict the levodopa response (LR) of the patients using leave-one-subject-out cross-validation. RESULTS: The LR predicted by the LRR model agreed with that calculated by the classic ALCT (ICC = 0.95). When the LRR model was used to detect patients with a positive LR, the positive predictive value was 0.94. CONCLUSIONS: Machine learning based on wearable sensor data and the iTUG test may be effective and comprehensive for evaluating LR and predicting the benefit of dopaminergic therapy.

Nasojejunal Tube Placement for Levodopa-carbidopa Intestinal Gel Treatment by Neurologists in Patients with Advanced Parkinson's Disease: A Retrospective Observational Study.

Introduction Short-term levodopa-carbidopa intestinal gel (LCIG) treatment using nasojejunal (NJ) tubes (NJ-LCIG test) is recommended for patients with advanced Parkinson's disease to ensure compatibility with this treatment system prior to permanent percutaneous endoscopic gastrojejunostomy. However, there have been no studies on NJ tube insertion by neurologists or on possible differences in treatment efficacy based on the NJ tube insertion method or tube tip position. We therefore investigated the effects of LCIG with NJ tube placement performed by a neurologist. Methods This retrospective observational study included 13 patients with advanced Parkinson's disease and NJ tube placement between March 1, 2020, and October 31, 2023. A neurologist performed all NJ tube placements, and the daily off-time and dyskinesia time before and after NJ tube placement were compared. We also investigated the effects of differences in the NJ tube tip site. Results NJ tubes were placed using either a combination of X-ray fluoroscopy-guided insertion and gastric motility methods (23.1%) or X-ray fluoroscopy-guided insertion alone (76.9%). All tubes were successfully placed in the descending duodenum (15.4%), ascending duodenum (23.1%), or jejunum (61.5%). The off time decreased significantly after the NJ-LCIG test (pre-NJ-LCIG test, 6.6 h [5.1-8.1] vs. post-NJ-LCIG test, 2.0 h [0.8-3.5], p<0.01). There was no difference in effectiveness based on the site of NJ tube tip placement. Conclusion Our results suggest that neurologists can place NJ tubes and that the NJ-LCIG test can also improve off-time, regardless of the placement site.

Satisfaction with videoconferencing support for levodopa-carbidopa intestinal gel: An observational study.

Background: Levodopa-carbidopa intestinal gel (LCIG) is a continuously delivered Parkinson's disease therapy intended to stabilize plasma levodopa levels. Patients receiving LCIG require education and follow-up. Some LCIG support programs use video-assisted telenursing. Objective: To examine how videoconferencing impacts satisfaction with LCIG support programs. Methods: FACILITATE CARE (Feasibility of video-Assisted Care for Intestinal Levodopa Infusion with Telenursing - observAtional Trial Evaluating patient and Caregiver Acceptance in REal life) was a 12-week, prospective, open-label, 2-arm, parallel-group, observational study assessing satisfaction with LCIG support in patients who self-assigned to video or audio-only arms. Patients aged 18-85 years had completed LCIG titration and owned a videoconferencing device (video arm only). A visual analog scale measured satisfaction (1-10, 10 being most satisfied). Results: Patients' mean (standard deviation) ages were 67.9 (7.4, n = 26) and 71.1 (6.2, n = 15) years in the video and audio arms, respectively. Patients, caregivers, and physicians in both groups reported satisfaction scores of 8-10 with LCIG support personnel, communication access, and assistance with becoming independent. At week 12, the Modified Caregiver Strain Index least square means change from baseline was lower in the video vs. audio arm (-2.3 [1.0] vs. 1.6 [1.2]). LCIG support personnel travel time was lower in the video vs. audio arm (125.7 [70.2] vs. 203.0 [70.0] minutes). Conclusions: LCIG support programs are associated with high patient, caregiver, and physician satisfaction; video and audioconferencing satisfaction are similarly high. Video-assisted telenursing may be a convenient communication avenue and may reduce caregiver burden. Registration: ClinicalTrials.gov; NCT04500106.

Case report: Levodopa challenge test is important in identifying dopamine-induced freezing of gait in patient with Parkinson's disease.

Introduction: Freezing of gait (FOG) is a disabling and heterogeneous symptom in patients with Parkinson's disease (PD). Among them, dopamine-induced FOG is rare and difficult to identify. The treatment of dopamine-induced FOG is complex. Case presentation: We herein presented a case of PD patient who complicated with refractory FOG. It was identified as dopamine-induced FOG during levodopa challenge test. Her symptoms were alleviated after we reduced the total equivalent dosage of levodopa. Conclusion: Our report emphasizes the importance of levodopa challenge test in identifying different types of FOG, which is very important for further adjusting treatment.