Can AI predict walking independence in patients with stroke upon admission to a recovery-phase rehabilitation ward?

Ono K, Takahashi R, Morita K, Ara Y, Abe S, Ito S, Uno S, Abe M, Shirasaka T. Can AI predict walking independence in patients with stroke upon admission to a recovery-phase rehabilitation ward? Jpn J Compr Rehabil Sci 2024; 15: 1-7. Objective: This study aimed to develop a prediction model for walking independence in patients with stroke in the recovery phase at the time of hospital discharge using Prediction One, an artificial intelligence (AI)-based predictive analysis tool, and to examine its utility. Methods: Prediction One was used to develop a prediction model for walking independence for 280 patients with stroke admitted to a rehabilitation ward-based on physical and mental function information at admission. In 134 patients with stroke hospitalized during different periods, accuracy was confirmed by calculating the correct response rate, sensitivity, specificity, and positive and negative predictive values based on the results of AI-based predictions and actual results. Results: The prediction accuracy (area under the curve, AUC) of the proposed model was 91.7%. The correct response rate was 79.9%, sensitivity was 95.7%, specificity was 62.5%, positive predictive value was 73.6%, and negative predictive value was 93.5%. Conclusion: The accuracy of the prediction model developed in this study is not inferior to that of previous studies, and the simplicity of the model makes it highly practical.

Factors associated with symptomatic urinary tract infection in persons with spinal cord lesions who perform clean intermittent catheterization with single-use catheters.

OBJECTIVES: To investigate factors associated with symptomatic urinary tract infection (sUTI) in persons with chronic spinal cord lesion (SCL) who were using single-use catheters for intermittent self-catheterization (ISC). METHODS: Among respondents to an internet survey on the burden of illness on persons with SCL who were considered to be able to perform ISC, 111 persons using single-use catheters were included to examine factors associated with self-reported sUTI by univariate as well as multivariable analysis. RESULTS: The incidence of sUTI was significantly higher in males than in females (56.9% vs. 31.6%, p = .011), persons with stocks of antibiotics than those without it (82.9% vs. 28.6%, p < .011), and persons with more frequent bleeding during catheterization than those with less frequent bleeding (100% vs. 46.5%, p = .036). The incidence did not significantly differ between respective groups when various variables were evaluated by other characteristics of the participants, adherence to ISC procedures, and complications. On multivariable analysis, male gender and stocks of antibiotics were significant independent factors for sUTI. CONCLUSIONS: Male gender and stocks of antibiotics were associated with sUTI in persons with SCL who were performing ISC with single-use catheters.

Time-resolved laser-induced fluorescence spectroscopy using CW diode laser for diagnostics of argon-ion velocity distribution near AC-biased electrode.

Controlling the ion velocity in an ion sheath by applying an alternating current (AC) voltage to an electrode and/or a substrate is critical in plasma material processes. To externally control the velocity distribution of incident ions on a substrate, the application of tailored-waveform AC voltages instead of sinusoidal voltages has garnered interest in recent years. In this study, to investigate temporal changes in ion-velocity distributions, we developed a time-resolved laser-induced fluorescence spectroscopy (LIF) system using a continuous-wave diode laser as an excitation-laser source. A time-resolved LIF system entails the capture of temporally continuous and spectrally discrete LIF spectra during an AC voltage cycle. By measuring temporal changes in the LIF signal intensity at various excitation-laser wavelengths, the argon-ion velocity distribution near the electrode following the AC voltage can be characterized. The results of applying sinusoidal, triangular, and rectangular bias waveforms indicate that the LIF measurement scheme proposed herein can be used to investigate the dynamic behavior of ion-velocity distributions controlled by tailored-waveform AC voltages.

A novel mouse model for investigating α-synuclein aggregates in oligodendrocytes: implications for the glial cytoplasmic inclusions in multiple system atrophy.

The aggregated alpha-synuclein (αsyn) in oligodendrocytes (OLGs) is one of the pathological hallmarks in multiple system atrophy (MSA). We have previously reported that αsyn accumulates not only in neurons but also in OLGs long after the administration of αsyn preformed fibrils (PFFs) in mice. However, detailed spatial and temporal analysis of oligodendroglial αsyn aggregates was technically difficult due to the background neuronal αsyn aggregates. The aim of this study is to create a novel mouse that easily enables sensitive and specific detection of αsyn aggregates in OLGs and the comparable analysis of the cellular tropism of αsyn aggregates in MSA brains. To this end, we generated transgenic (Tg) mice expressing human αsyn-green fluorescent protein (GFP) fusion proteins in OLGs under the control of the 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNP) promoter (CNP-SNCAGFP Tg mice). Injection of αsyn PFFs in these mice induced distinct GFP-positive aggregates in the processes of OLGs as early as one month post-inoculation (mpi), and their number and size increased in a centripetal manner. Moreover, MSA-brain homogenates (BH) induced significantly more oligodendroglial αsyn aggregates than neuronal αsyn aggregates compared to DLB-BH in CNP-SNCAGFP Tg mice, suggestive of their potential tropism of αsyn seeds for OLGs. In conclusion, CNP-SNCAGFP Tg mice are useful for studying the development and tropism of αsyn aggregates in OLGs and could contribute to the development of therapeutics targeting αsyn aggregates in OLGs.

TMEM119-positive microglia were increased in the brains of patients with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that has been reported to be affected by inflammatory cells, such as microglia and macrophages, through the concept of non-cell autonomous neuronal death. Resident microglia in the human brain and monocyte-derived macrophages (MoDM) infiltrating in tissues are difficult to distinguish. Therefore, the effects of microglia and MoDMs in ALS remain poorly understood. This study aimed to investigate the role of resident microglia and MoDMs in the pathogenesis of ALS using postmortem brain and spinal cord samples. The samples used for immunohistochemical analysis included 11 cases of sporadic ALS and 11 age-matched controls. We stained the cells with TMEM119 to detect resident microglia and CCR2 to detect MoDMs. In ALS cases, TMEM119-immunopositive resident microglia were abundant in the motor cortex and subcortical white matter (SWM) of the motor area, whereas CCR2-immunopositive MoDM was similar to control cases. In addition, the mean density of CD68-immunopositive cells in the SWM significantly correlated with the mean density of pTDP-43-positive GCIs. These results suggest that resident microglial activation plays an important role in the cerebral pathogenesis of ALS and may provide novel therapeutic strategies to target excessive activation of resident microglia in ALS.

Decreased grip strength is associated with paraspinal muscular oxidative stress in female lumbar degenerative disease patients.

We aimed to investigate the relationship between superoxide dismutase 2-related oxidative stress in the paraspinal muscles and spinal alignment, clinical skeletal muscle parameters, and mitochondrial function. Multifidus muscle samples from patients who underwent posterior lumbar surgery were analyzed. Patients with diseases affecting oxidative stress and spinal alignment were excluded. The superoxide dismutase 2 redox index was defined as the ratio of reactive oxygen species (superoxide) to antioxidant enzymes (superoxide dismutase 2) and was used as an index of oxidative stress. Patients were divided into two groups based on the superoxide dismutase 2 redox index. Spinal alignment, clinical skeletal muscle parameters, and succinic dehydrogenase (SDH) mean grayscale value were compared between the groups, with analyzes for both sexes. Multiple regression analyzes were used to adjust for the confounding effect of age on variables showing a significant difference between the two groups. Thirty-five patients with lumbar degenerative diseases were included. No significant differences were observed between the two groups for any of the parameters in males; however, females with a higher superoxide dismutase 2 redox index had greater lumbar lordosis, lower grip strength, and higher SDH mean grayscale value than those with a lower index. Multiple regression analyzes revealed that the superoxide dismutase 2 redox index was an independent explanatory variable for lumbar lordosis, grip strength, and SDH mean grayscale value in female patients. In conclusion, superoxide dismutase 2-related oxidative stress in the paraspinal muscles was associated with mitochondrial dysfunction and decreased grip strength in female lumbar degenerative disease patients.

Basic Science in Movement Disorders: Fueling the Engine of Translation into Clinical Practice.

Basic Science is crucial for the advancement of clinical care for Movement Disorders. Here, we provide brief updates on how basic science is important for understanding disease mechanisms, disease prevention, disease diagnosis, development of novel therapies and to establish the basis for personalized medicine. We conclude the viewpoint by a call to action to further improve interactions between clinician and basic scientists. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

HELLP Syndrome at 20 Gestational Weeks Managed Using the Mississippi Protocol: A Case Report.

Hemolysis, elevated liver enzyme levels, and low platelet count (HELLP) syndrome is one of the most severe complications of hypertensive disorders of pregnancy. HELLP syndrome occurring before 22 gestational weeks (GWs) is extremely rare, and patients prevalently exhibit underlying maternal diseases or fetal abnormalities. Here, we report the case of a pregnant woman who had HELLP syndrome at 20 GWs without any obvious underlying maternal diseases or fetal abnormalities. A 38-year-old pregnant woman was referred to Kobe University Hospital from another hospital at 19 + 5/7 GWs for hypertension, proteinuria, generalized edema, and fetal growth restriction. She was diagnosed with partial HELLP syndrome according to the Mississippi classification at 20 + 2/7 GWs. The patient was managed following the Mississippi protocol, including intravenous dexamethasone, magnesium sulfate, and antihypertensive drugs. She received intensive blood pressure and laboratory data monitoring using an arterial line and additional treatments, including platelet transfusion, intravenous haptoglobin infusion, and human atrial natriuretic peptide. The pregnancy ended in an induced delivery at 20 + 3/7 GWs, and she was discharged without complications 10 days postnatal. We performed laboratory tests for diagnosing underlying diseases but identified no obvious underlying diseases. This report indicates that early and intensive treatment of patients with HELLP syndrome occurring before 22 GWs according to the Mississippi protocol may enable clinicians to complete pregnancy termination without maternal complications and provide useful information to clinical practitioners in perinatal medicine.

Current trends in basic research on Parkinson's disease: from mitochondria, lysosome to α-synuclein.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive degeneration of dopaminergic neurons in the substantia nigra and other brain regions. A key pathological feature of PD is the abnormal accumulation of α-synuclein protein within affected neurons, manifesting as Lewy bodies and Lewy neurites. Despite extensive research efforts spanning several decades, the underlying mechanisms of PD and disease-modifying therapies remain elusive. This review provides an overview of current trends in basic research on PD. Initially, it discusses the involvement of mitochondrial dysfunction in the pathogenesis of PD, followed by insights into the role of lysosomal dysfunction and disruptions in the vesicular transport system. Additionally, it delves into the pathological and physiological roles of α-synuclein, a crucial protein associated with PD pathophysiology. Overall, the purpose of this review is to comprehend the current state of elucidating the intricate mechanisms underlying PD and to outline future directions in understanding this disease.

Ictal Direct Current Shifts Preceded Much Earlier Than High Frequency Oscillations After Status: Is It the Effect of Status or Antiseizure Medication?

PURPOSE: While spikes and sharp waves are considered as markers of epilepsy in conventional electroencephalography, ictal direct current (DC) shifts and high-frequency oscillations (HFOs) appear to be useful biomarkers for epileptogenicity. We analyzed how ictal DC shifts and HFOs were affected by focal status epilepticus and antiseizure medications (ASMs). METHODS: A 20-year-old female patient who underwent long-term intracranial electrode implantation for epilepsy surgery presented with 72 habitual seizures and a focal status epilepticus episode lasting for 4 h. Ten, 3, and 10 consecutive habitual seizures were analyzed before the status, after the status, and after ASM (valproate) loading, respectively. RESULTS: Before and immediately after the status, ictal DC shifts remained the same in terms of the amplitude, duration, and slope of DC shifts. High-frequency oscillations also remained the same in terms of the duration, frequency, and power except for the power of the lower frequency band. After ASM loading, the duration, amplitude, and slope of the ictal DC shift were significantly attenuated. The duration, frequency, and power of the HFOs were significantly attenuated. Furthermore, the interval between the DC onset and HFO onset was significantly longer and the interval between the HFO onset and ictal DC shift peak was significantly shorter. CONCLUSIONS: The attenuation of ictal DC shifts and HFOs after ASM loading implies that astrocyte and neuronal activity may be both attenuated by ASMs. This finding may help with our understanding of the pathophysiology of epilepsy and can aid with the discovery of new approaches for epilepsy management.

Combined genetic polymorphisms of the GSTT1 and NRF2 genes increase susceptibility to cisplatin-induced ototoxicity: A preliminary study.

OBJECTIVE: The genotype-phenotype relationship in cisplatin-induced ototoxicity remains unclear. By assessing early shifts in distortion product otoacoustic emission (DPOAE) levels after initial cisplatin administration, we aimed to discriminate patients' susceptibility to cisplatin-induced ototoxicity and elucidate their genetic background. STUDY DESIGN: A prospective cross-sectional study. SETTING: Tertiary referral hospital in Japan. PATIENTS: Twenty-six patients with head and neck cancer were undergoing chemoradiotherapy with three cycles of 100 mg/m2 cisplatin. INTERVENTIONS: Repetitive pure-tone audiometry and DPOAE measurements, and blood sampling for DNA extraction were performed. Patients were grouped into early ototoxicity presence or absence based on whether DPOAE level shifts exceeded the corresponding reference limits of the 21-day test interval. MAIN OUTCOME MEASURES: Hearing thresholds after each cisplatin cycle, severity of other adverse events, and polymorphisms in cisplatin-induced ototoxicity-associated genes were compared. RESULTS: Early ototoxicity was present in 14 and absent in 12 patients. Ototoxicity presence on DPOAEs was associated with greater progression of hearing loss in frequencies ≥2 kHz throughout therapy and with higher ototoxicity grades compared with ototoxicity absence. Ototoxicity was further associated with grade ≥2 nausea. Ototoxicity presence was genetically associated with the GSTT1 null genotype and G-allele of NFE2L2 rs6721961, whereas ototoxicity absence was associated with the GSTM1 null genotype. Dose-dependent progression of hearing loss was the greatest in the combined genotype pattern of GSTT1 null and the T/G or G/G variants of rs6721961. CONCLUSION: Early DPOAE changes reflected genetic vulnerability to cisplatin-induced ototoxicity. Hereditary insufficiency of the antioxidant defense system causes severe cisplatin-induced hearing loss and nausea.

Specific consistency score for rational selection of epilepsy resection surgery candidates.

OBJECTIVE: Degree of indication for epilepsy surgery is determined by taking multiple factors into account. This study aimed to investigate the usefulness of the Specific Consistency Score (SCS), a proposed score for focal epilepsy to rate the indication for epilepsy focal resection. METHODS: This retrospective cohort study included patients considered for resective epilepsy surgery in Kyoto University Hospital from 2011 to 2022. Plausible epileptic focus was tentatively defined. Cardinal findings were scored based on specificity and consistency with the estimated laterality and lobe. The total points represented SCS. The association between SCS and the following clinical parameters was assessed by univariate and multivariate analysis: (1) probability of undergoing resective epilepsy surgery, (2) good postoperative seizure outcome (Engel I and II or Engel I only), and (3) lobar concordance between the noninvasively estimated focus and intracranial electroencephalographic (EEG) recordings. RESULTS: A total of 131 patients were evaluated. Univariate analysis revealed higher SCS in the (1) epilepsy surgery group (8.4 [95% confidence interval (CI) = 7.8-8.9] vs. 4.9 [95% CI = 4.3-5.5] points; p < .001), (2) good postoperative seizure outcome group (Engel I and II; 8.7 [95% CI = 8.2-9.3] vs. 6.4 [95% CI = 4.5-8.3] points; p = .008), and (3) patients whose focus defined by intracranial EEG matched the noninvasively estimated focus (8.3 [95% CI = 7.3-9.2] vs. 5.4 [95% CI = 3.5-7.3] points; p = .004). Multivariate analysis revealed areas under the curve of .843, .825, and .881 for Parameters 1, 2, and 3, respectively. SIGNIFICANCE: SCS provides a reliable index of good indication for resective epilepsy surgery and can be easily available in many institutions not necessarily specializing in epilepsy.

Functional vagal paraganglioma developing 15 years after resection of a retroperitoneal paraganglioma.

The patient, a 40-year-old woman, was diagnosed as having a functional right vagal paraganglioma (PGL) 15 years after undergoing resection for a retroperitoneal PGL. 123I-MIBG scintigraphy showed no accumulation, but as the blood noradrenaline and urinary normetanephrine concentrations were elevated, the tumor was judged as being functional, and surgery was scheduled. The patient was started on doxazosin infusion and embolization of the tumor feeding vessel was performed before the surgery. Intraoperative examination showed that the tumor was contiguous with the vagal nerve, necessitating combined resection of the vagal nerve with the tumor. Postoperatively, the catecholamine levels returned to normal range. Histopathologically, the tumor was diagnosed as a moderately differentiated, intermediate-malignant-grade PGL, with a GAPP score of 4 to 6. No non-chromaffin tissue was observed in the tumor background, so that the functional vagal PGL was considered as a sporadic metachronous tumor rather than as a metastasis from the retroperitoneal PGL. More than half of head and neck paragangliomas (HNPGLs) are reported to arise in the carotid body, and about 5% from the vagal nerve. In addition, HNPGLs rarely produce catecholamines. Herein, we consider the relationship with the previously resected retroperitoneal PGL based on a review of the literature.

Experimental Animal Models of Prodromal Parkinson's Disease.

There is an estimated 35-45% loss of striatal dopamine at the time of diagnosis of Parkinson's disease (PD), and cases clinically diagnosed in the early stages may already be pathologically in advanced stages. Recent large-scale clinical trials of disease-modifying therapies (DMT) also suggest the necessity of targeting patients at earlier stages of the disease. From this perspective, the prodromal phase of PD is currently the focus of attention, emphasizing the need for a prodromal mouse model that accurately reflects the pathophysiology, along with early biomarkers. To establish prodromal animal model of PD with high face validity that reflects the disease state, the model must possess high construct validity that accurately incorporates clinical and pathological features in the prodromal phase. Furthermore, as a preclinical model of DMT, the model must possess high predictive validity to accurately evaluate the response to intervention. This review provides an overview of animal models which reflect the characteristics of prodromal PD, including alpha-synuclein (aS) accumulation and associated early non-motor symptoms, with a focus on the aS propagation model and genetic model. In addition, we discuss the challenges associated with these models. The genetic model often fails to induce motor symptoms, while aS propagation models skip the crucial step of initial aS aggregate formation, thereby not fully replicating the entire natural course of the disease. Identifying factors that induce the transition from prodromal to symptomatic phase is important as a preclinical model for DMT to prevent or delay the onset of the disease.

High frequency of circulating non-classical monocytes is associated with stable remission in relapsing-remitting multiple sclerosis.

'No evidence of disease activity (NEDA)', judged by clinical and radiological findings, is a therapeutic goal in patients with multiple sclerosis (MS). It is, however, unclear if distinct biological mechanisms contribute to the maintenance of NEDA. To clarify the immunological background of long-term disease stability defined by NEDA, circulating immune cell subsets in patients with relapsing-remitting MS (RRMS) were analyzed using flow cytometry. Patients showing long-term NEDA (n = 31) had significantly higher frequencies of non-classical monocytes (NCMs) (6.1% vs 1.4%) and activated regulatory T cells (Tregs; 2.1% vs 1.6%) than those with evidence of disease activity (n = 8). The NCM frequency and NCMs to classical monocytes ratio (NCM/CM) positively correlated with activated Treg frequency and duration of NEDA. Co-culture assays demonstrated that NCMs could increase the frequency of activated Tregs and the expression of PD-L1, contributing to development of Tregs, was particularly high in NCMs from patients with NEDA. Collectively, NCMs contribute to stable remission in patients with RRMS, possibly by increasing activated Treg frequency. In addition, the NCM frequency and NCM/CM ratio had high predictive values for disease stability (AUC = 0.97 and 0.94, respectively), suggesting these markers are potential predictors of a long-term NEDA status in RRMS.

Mutant α-synuclein causes death of human cortical neurons via ERK1/2 and JNK activation.

Synucleinopathies refer to a group of disorders characterized by SNCA/α-synuclein (α-Syn)-containing cytoplasmic inclusions and neuronal cell loss in the nervous system including the cortex, a common feature being cognitive impairment. Still, the molecular pathogenesis of cognitive decline remains poorly understood, hampering the development of effective treatments. Here, we generated induced pluripotent stem cells (iPSCs) derived from familial Parkinson's disease (PD) patients carrying SNCA A53T mutation, differentiating them into cortical neurons by a direct conversion method. Patient iPSCs-derived cortical neurons harboring mutant α-Syn exhibited increased α-Syn-positive aggregates, shorter neurites, and time-dependent vulnerability. Furthermore, RNA-sequencing analysis, followed by biochemical validation, identified the activation of the ERK1/2 and JNK cascades in cortical neurons with SNCA A53T mutation. This result was consistent with a reverted phenotype of neuronal death in cortical neurons when treated with ERK1/2 and JNK inhibitors, respectively. Our findings emphasize the role of ERK1/2 and JNK cascades in the vulnerability of cortical neurons in synucleinopathies, and they could pave the way toward therapeutic advancements for synucleinopathies.

Risk factors for recurrence of frozen shoulder after shoulder manipulation under ultrasound-guided cervical nerve root block.

Background: This study aimed to investigate risk factors for recurrence of frozen shoulder after shoulder manipulation under ultrasound-guided cervical nerve root block (MUC). Methods: We retrospectively reviewed 135 frozen shoulders in 121 patients who underwent MUC. We defined frozen shoulder as a limited shoulder range of motion (ROM) (passive forward flexion <120°, external rotation <30°, or internal rotation lower than L3). Patients fulfilling any one criteria were considered to have frozen shoulder. If patients continued to have severe pain and limited ROM at 3 months after MUC, we defined as recurrence of frozen shoulder and they were offered a further MUC or arthroscopic capsular release (ACR). We compared the ROM, Constant Shoulder (CS) score, and University of California, Los Angeles score before and 3 months after MUC between patients with the successful of MUC group (Success group) with those recurrence of frozen shoulder who required a further MUC or ACR group (Recurrence group). Multiple logistic regression analysis was used to identify risk factors for recurrence of frozen shoulder after MUC. Results: Patients who underwent MUC were retrospectively enrolled and divided into: the successful of MUC group (Success group, n = 112) and required a further MUC or ACR group (Recurrence group, n = 9). The Recurrence group had significantly lower external rotation and CS score before MUC than those in the Success group (P < .05). The Recurrence group showed significantly inferior all ROM and functional scores 3 months after MUC (P < .05). The levels of blood glucose and hemoglobin A1c both before and 3 months after MUC in the Recurrence group showed inferior compared with those of Success group. The difference, although not statistically significant, trended towards significance (before MUC/3 months after MUC; the glucose levels P = .06/.06, the hemoglobin A1c levels P = .07/.09, respectively). The visual analog scale pain score (at rest, during activity, at night) both before and 3 months after MUC in the Recurrence group showed significantly higher scores compared with those of Success group (P < .05). Multiple logistic regression analysis revealed that lower CS score before MUC was independent risk factor for recurrence of frozen shoulder after MUC. Conclusion: The overall incidence of recurrence of frozen shoulder after MUC was 7.4%. The lower CS score before MUC was an independent risk factor for recurrence of frozen shoulder after MUC. Moreover, patients in the Recurrence group tended to have poorly controlled diabetes and higher visual analog scale pain score both before and 3 months after MUC.

Early Postoperative Stiffness After Arthroscopic Rotator Cuff Repair Correlates With Improved Tendon Healing.

PURPOSE: To assess whether early postoperative stiffness predicts long-term stiffness and its relationship with repair integrity in patients who undergo arthroscopic rotator cuff repair (ARCR). METHODS: This was a single-center retrospective study; 427 patients undergoing primary ARCR by a board-certified orthopaedic surgeon over 4 years were considered. Patients with at least 1 year of follow-up were categorized into stiff and non-stiff groups based on their range of motion (ROM) at 3 months' postoperatively. Stiffness was defined as passive forward flexion <120°, external rotation <30°, or internal rotation below L3. We evaluated clinical outcomes using demographics, ROM, Constant Shoulder (CS) score, University of California, Los Angeles (UCLA) score, and visual analog scale (VAS) for pain preoperatively and at 3, 6, and 12 months' postoperatively. Stiffness, retear rates, and tendon integrity were assessed via magnetic resonance imaging at 12 months. RESULTS: Of 155 patients meeting the inclusion criteria, 68 (43.9%) were stiff, and 87 (56.1%) were non-stiff. The stiff group had significantly lower preoperative CS and UCLA scores (P = .013/.014) and greater VAS score (P = .034). At 3 months, this group showed lower ROM and functional scores (P < .001), persisting at 6 and 12 months (except internal rotation) (P < .001). Their 12-month VAS score was greater (P = .024). Postoperative stiffness occurred in 10.3% of the stiff group and 2.3% of the non-stiff group (P = .035). The 12-month retear rate was 5.9% in the stiff group and 17.2% in the non-stiff group (P = .032). Minimal clinically important difference analysis indicated ROM changes but limited functional score changes in the 2 groups. CONCLUSIONS: This study showed that early postoperative shoulder stiffness correlates with lower preoperative functional scores and greater pain levels. Shoulder stiffness at 3 months' post-ARCR predicts 12-month shoulder stiffness but indicates better tendon integrity. While early stiffness is linked to lower functional scores and more pain, its long-term clinical impact seems limited. LEVEL OF EVIDENCE: Level III, retrospective comparison study.