Tinnitus: an underreported condition following microvascular decompression for hemifacial spasm.

PURPOSE: While hearing loss is a well-known condition following microvascular decompression (MVD) for hemifacial spasm (HFS), tinnitus is an underreported one. This study aims to identify prevalence, characteristics, severity, and predictors of tinnitus following MVD for HFS. METHODS: A single-center cohort of 55 HFS patients completed a questionnaire approximately 5 years following MVD. Data encompassed tinnitus presence, side, type, onset, and severity measured by a 10-point Visual Analogue Scale (VAS). Descriptive, correlation, and logistic regression analyses were conducted. RESULTS  : At surgery, participants' median age was 58 years (IQR 52-65). The median duration of HFS symptoms before surgery was 5 years (IQR 3-8), slightly predominant on the left (60%). Postoperative tinnitus was reported by 20 patients (36%), versus nine (16%) that reported preoperative tinnitus. Postoperative tinnitus was ipsilateral on the surgical side in 13 patients (65%), bilateral in six (30%), and contralateral in one (5%). Among patients with bilateral postoperative tinnitus, 33% did not have this preoperatively. Tinnitus was continuous in 70% of cases and pulsatile in 30%. Onset of new tinnitus was in 58% immediately or within days, in 25% within three months, and in 17% between three months and one year after surgery. The mean severity of postoperative tinnitus was 5.1 points on the VAS. Preoperative tinnitus and presence of arachnoid adhesions had suggestive associations with postoperative tinnitus in initial analyses (p = 0.005 and p = 0.065). However, preoperative tinnitus was the only significant predictor of postoperative tinnitus (p = 0.011). CONCLUSION: Tinnitus is a common condition following MVD for HFS, with a moderate overall severity. Causes behind postoperative tinnitus remain obscure but could be related to those of postoperative hearing loss in this patient population. Clinicians should be aware of tinnitus following MVD and vigilantly monitor its occurrence, to facilitate prevention efforts and optimize outcome for HFS patients undergoing MVD.

To be thorough or tailored: influence of the arachnoid dissection range on the surgical outcomes of microvascular decompression for hemifacial spasm.

BACKGROUND: As one of the most fundamental elements in exposure and decompression, the dissection of arachnoid has been rarely correlated with the surgical results in studies on Microvascular decompression (MVD) procedures for Hemifacial spasm (HFS). MATERIALS AND METHODS: Patients' records of the HFS cases treated with MVD from January 2016 to December 2021 in our center was retrospectively reviewed. The video of the procedures was inspected thoroughly to evaluate the range of dissection of arachnoid. Four areas were defined in order to facilitate the evaluation of the dissection range. The correlation between the arachnoid dissection and the surgical outcomes were analyzed. RESULTS: The arachnoid structures between the nineth cranial nerve and the seventh, eighth cranial nerves were dissected in all cases, other areas were entered based on different consideration. The rate of neurological complications of the extended dissection pattern group was higher than that of the standard pattern group (P < 0.05). The procedures in which the arachnoid structure above the vestibulocochlear nerve was dissected, led to more neurological complications (P < 0.05). CONCLUSION: Thorough dissection as an initial aim for all cases was not recommended in MVD for HFS, arachnoid dissection should be tailored to achieving safety and effectiveness during the procedure.

[An analysis of clinical efficacy of microvascular decompression for 21 inpatients suffering from primary hemifacial spasm].

Objective:To assess the effectiveness of microvascular decompression（MVD） in treating inpatients suffering from primary hemifacial spasm（HFS）. Methods:A total of 21 inpatients with HFS underwent MVD. The clinical effect was follow up evaluated according to the clinical symptoms until post operative 6 months. Results:The effective rate of MVD for 1 day, 14 days, 1 month, 3 months and 6 months post-operation was 95.2%, 100%, 100%, 100% and 100%, respectively.one patient had transient tinnitus and the symptom disappeared within 6 days postoperatively.one patient developed postoperative incomplete facial paralysis（HB grade IV facial nerve function, grade Ⅱ） and recovered 6 days after surgery; There was no cerebrospinal fluid leakage, intracranial infection, death or disability occurred during follow-up. Conclusion:Microvascular decompression is a safe and effective method for the treatment of primary hemifacial spasm, which is worthy of clinical promotion.

White matter structural changes before and after microvascular decompression for hemifacial spasm.

Hemifacial spasm (HFS) is a syndrome characterized by involuntary contractions of the facial muscles innervated by the ipsilateral facial nerve. Currently, microvascular decompression (MVD) is an effective treatment for HFS. Diffusion weighted imaging (DWI) is a non-invasive advanced magnetic resonance technique that allows us to reconstruct white matter (WM) virtually based on water diffusion direction. This enables us to model the human brain as a complex network using graph theory. In our study, we recruited 32 patients with HFS and 32 healthy controls to analyze and compare the topological organization of whole-brain white matter networks between the groups. We also explored the potential relationships between altered topological properties and clinical outcomes. Compared to the HC group, the white matter network was disrupted in both preoperative and postoperative groups of HFS patients, mainly located in the somatomotor network, limbic network, and default network (All P < 0.05, FDR corrected). There was no significant difference between the preoperative and postoperative groups (P > 0.05, FDR corrected). There was a correlation between the altered topological properties and clinical outcomes in the postoperative group of patients (All P < 0.05, FDR corrected). Our findings indicate that in HFS, the white matter structural network was disrupted before and after MVD, and that these alterations in the postoperative group were correlated with the clinical outcomes. White matter alteration here described may subserve as potential biomarkers for HFS and may help us identify patients with HFS who can benefit from MVD and thus can help us make a proper surgical patient selection.

Objective demonstration of eyelid spasm relief with smartphone and custom software in hemifacial spasm patients.

PURPOSE: To objectively demonstrate eyelid spasms relief in hemifacial spasm (HFS) patients using a smartphone and a custom-made software. METHODS: Nineteen patients with HFS had standardized videos recorded with a smartphone (iPhone 6S, Apple) camera before and 15 days after receiving onabotulinumtoxinA injections. Nineteen age-matched control subjects were also assessed. The Eye Aspect Ratio (EAR) is an algorithm previously described to determine whether the eye is opened or closed. When the eye is closed, EAR tends to be closer to zero. Analogously, if the eye is wide open, values are greater. A custom-made software using the EAR concept was developed and pre- and post-treatment EARs were analyzed to assess HFS patients. RESULTS: Botulinum toxin (BoNT) injections led to a significant increase in the average EAR of the affected side: + 10.4% (p = 0.0175) of HFS patients, compared to baseline. Mean EAR before BoNT applications were significantly lower (16.2%) on the affected side (0.25 ± 0.05) of HFS patients when compared to controls (0.30 ± 0.05, p = 0.004). After BoNT injections, no statistically significant difference was observed for the average EAR between the affected side of HFS patients (0.27 ± 0.04) and controls (p = 0.20). CONCLUSIONS: Use of a smartphone and custom-made software objectively demonstrated eyelid spasm relief in patients with HFS. Additional refinement of this system could permit more accurate assessments of treatment response rates for each patient, making it possible to be used in clinical practice.

Comparison of Radiofrequency Ablation and Craniotomy Microvascular Decompression for Treatment of Hemifacial Spasm.

BACKGROUND: Hemifacial spasm (HFS) is distinguished by sudden and involuntary spasms of the facial muscles, predominantly on one side of the face. Microvascular decompression (MVD) is an efficacious surgical technique for treating HFS; however, MVD may occasionally lead to noteworthy postoperative complications. Previously, we reported the successful utilization of an innovative awake computed tomography-guided percutaneous puncture of the stylomastoid foramen for administering radiofrequency ablation (RFA) therapy in the treatment of HFS. STUDY DESIGN: Prospective clinical research study. SETTING: Department of Anesthesiology and Pain Medical Center, Ningbo, China. OBJECTIVES: The aim of this study was to compare and contrast the clinical outcomes and adverse reactions associated with attempts to use RFA and MVD to manage primary HFS. METHODS: Three hundred patients received either RFA or MVD treatment (Group R and Group M). We tracked and recorded each patient's cure rate, remission rate, intraoperative and postoperative complications, short-term and long-term therapeutic outcomes, hospitalization duration, hospitalization expenses, and operation time. RESULTS: One hundred and fifty-eight patients were placed in the R group, and 142 patients were sorted into the M group. In the R group, 87.34% of patients showed improvement, 9.49% experienced relief, and 3.16% experienced treatment failure. Similarly, in the M group, 85.92% of patients showed improvement, 10.56% experienced relief, and 3.52% experienced treatment failure. The difference in therapeutic efficacy between the 2 groups was not significant. However, the M group had significantly lower recurrence rates at 3 months, 6 months, and one year post-operation than the R group did. Notably, the M group also experienced a higher rate of postoperative complications. Among the complications reported in the M group were 25 cases of dizziness or headache (17.6%) following the operation, 22 cases of hearing damage, including one case of complete hearing loss on the side involved, and 28 cases of peripheral nerve injury with abnormal skin sensation. Postoperative facial paralysis occurred in 15 patients, including 10 cases of moderate to severe facial paralysis that were relieved to grade II after one year. In comparison, the R group had 40 cases of grade II and 53 cases of grade III, and no cases of more severe facial paralysis were found. There were also 13 cases of peripheral nerve injury, such as local skin numbness and tenderness. Importantly, there were no cases of facial hematoma, intracranial hemorrhage, infection, or any other complications in either group, and no fatalities occurred during the study period. LIMITATIONS: The limitations of this study are the exclusion of transient postoperative complications, the lack of in-person follow-up with patients, and the potential underestimation of certain complications. CONCLUSION: The short-term outcome was found to be comparable between the 2 treatment modalities. Notably, RFA demonstrates both safety and efficacy as a method for managing primary HFS; however, the procedure may lead to mild facial paralysis. In situations during which surgery is contraindicated, especially among elderly or high-risk surgical patients, percutaneous facial nerve RFA at the stylomastoid foramen may be considered as an alternative therapeutic approach.

Evaluating magnetic resonance imaging characteristics and risk factors for hemifacial spasm.

PURPOSE: The specific neurovascular compression (NVC) event responsible for the symptomatic manifestation of hemifacial spasm (HFS) remains difficult to assess accurately using magnetic resonance imaging (MRI). We aim to evaluate the MRI characteristics of HFS. METHOD: We retrospectively included patients with HFS and divided them into a test group (n = 186) and a validation group (n = 28). The presence, severity, and offending vessel type of NVC in each portion, and the orientation of the offending vessel around the facial nerve, were recorded. Conditional logistic regression analyses were performed to evaluate correlations using test group. The validation group was used to verify whether our findings improved diagnostic performance. RESULTS: Deformity in the proximal cisternal segment was significantly correlated with HFS occurrence (odds ratio [OR]: 256.58, p = .002), whereas contact was not (p = .233). Both contact and deformity in the root detachment point (OR: 19.98 and 37.22, p < .001 and p = .013, respectively) or attached segment (OR: 4.99 and 252.52, p = .001 and p < .001, respectively) were significantly correlated with HFS occurrence. Our findings improved specificity, positive predictive value, and accuracy of diagnosis than conventional diagnostic methods. The vertebral artery predominantly compress the facial nerve in the inferior-anterior position, the anterior inferior cerebellar artery predominantly in the inferior position, the posterior inferior cerebellar artery predominantly in the inferior position, vein predominantly in the posterior-superior position. CONCLUSIONS: This study further demonstrates that within the susceptible portion of facial nerve, different portions of the nerve respond differently to NVC. Each offending vessel has its own preferred conflict orientation. Our study offers reference for neurosurgeons in diagnosis and treatment.

Fully endoscopic microvascular decompression for hemifacial spasm: a clinical study and analysis.

Fully endoscopic microvascular decompression (MVD) of the facial nerve is the main surgical treatment for hemifacial spasm. However, the technique presents distinct surgical challenges. We retrospectively analyzed prior cases to consolidate surgical insights and assess clinical outcomes. Clinical data from 16 patients with facial nerve spasms treated at the Department of Neurosurgery in the First Affiliated Hospital of Bengbu Medical College, between August 2020 and July 2023, were retrospectively examined. Preoperatively, all patients underwent magnetic resonance angiography to detect any offending blood vessels; ascertain the relationship between offending vessels, facial nerves, and the brainstem; and detect any cerebellopontine angle lesions. Surgery involved endoscopic MVD of the facial nerve using a mini Sigmoid sinus posterior approach. Various operative nuances were summarized and analyzed, and clinical efficacy, including postoperative complications and the extent of relief from facial paralysis, was evaluated. Fully endoscopic MVD was completed in all patients, with the offending vessels identified and adequately padded during surgery. The offending vessels were anterior inferior cerebellar artery in 12 cases (75%), vertebral artery in 3 cases (18.75%), and posterior inferior cerebellar artery in 1 case (6.25%). Intraoperative electrophysiological monitoring revealed that the lateral spread response of the facial nerve vanished in 15 cases and remained unchanged in 1 case. Postoperative facial spasms were promptly alleviated in 15 cases (93.75%) and delayed in 1 case (6.25%). Two cases of postoperative complications were recorded-one intracranial infection and one case of tinnitus-both were resolved or mitigated with treatment. All patients were subject to follow-up, with no instances of recurrence or mortality. Fully endoscopic MVD of the facial nerve is safe and effective. Proficiency in endoscopy and surgical skills are vital for performing this procedure.

Microvascular decompression for hemifacial spasm after Bell's palsy: a retrospective clinical study.

OBJECTIVE: This study aimed to investigate the clinical characteristics of hemifacial spasm (HFS) after Bell's palsy and to evaluate the therapeutic efficacy of microvascular decompression (MVD). METHODS: A retrospective analysis was conducted on 18 patients who underwent MVD for HFS after Bell's palsy at our institution between January 1, 2017, and December 31, 2021. Clinical presentations, intraoperative findings, postoperative outcomes, and complications were comprehensively assessed. RESULTS: Neurovascular compression (NVC) was identified in all the 18 patients. The offending vessels included anterior inferior cerebellar artery (AICA) in 6 patients (33.3%), posterior inferior cerebellar artery (PICA) in 7 patients (38.9%), vertebral artery (VA) combined with AICA in 3 patients (16.7%), and VA alongside PICA in 2 patients (11.1%). Notably, marked arachnoid membrane adhesion was evident in 11 patients (61.1%). 15(83.3%) patients were cured immediately after MVD, delayed relief was found in 3 (16.7%) patients. During the follow-up period, recurrence was not documented. Surgical complications were limited to facial paralysis in 3 patients and auditory impairment in 1 patient. No additional surgical complications were recorded. CONCLUSIONS: In patients manifesting HFS after Bell's palsy, NVC predominantly underlies the etiology. MVD is a reliably safe and efficacious therapeutic intervention.

Letter to the editor: fully endoscopic microvascular decompression for hemifacial spasm: a clinical study and analysis.

This article presents a comprehensive analysis of microvascular decompression (MVD) surgery as a treatment option for hemifacial spasm (HFS). Beginning with a thorough literature review, it explores the historical context, prevalence, and underlying mechanisms of HFS, laying a robust foundation for discussing MVD. Various surgical techniques, from traditional microscopic to fully endoscopic approaches, are described, along with their procedural nuances and advantages. Clinical data, including patient demographics and surgical success rates, substantiate the efficacy of MVD in alleviating HFS symptoms. The discussion of postoperative complications provides valuable insights into practical challenges. However, limitations such as single-center design, lack of robust statistical analysis, and absence of comparative data between endoscopic and microscopic approaches diminish the article's potential impact. Recommendations for multicenter collaborations, enhanced statistical analyses, comparative studies, and discussions on surgical training could significantly enhance the article's contribution to neurosurgery practice.

The blink reflex and its modulation - Part 2: Pathophysiology and clinical utility.

The blink reflex (BR) is integrated at the brainstem; however, it is modulated by inputs from various structures such as the striatum, globus pallidus, substantia nigra, and nucleus raphe magnus but also from afferent input from the peripheral nervous system. Therefore, it provides information about the pathophysiology of numerous peripheral and central nervous system disorders. The BR is a valuable tool for studying the integrity of the trigemino-facial system, the relevant brainstem nuclei, and circuits. At the same time, some neurophysiological techniques applying the BR may indicate abnormalities involving structures rostral to the brainstem that modulate or control the BR circuits. This is a state-of-the-art review of the clinical application of BR modulation; physiology is reviewed in part 1. In this review, we aim to present the role of the BR and techniques related to its modulation in understanding pathophysiological mechanisms of motor control and pain disorders, in which these techniques are diagnostically helpful. Furthermore, some BR techniques may have a predictive value or serve as a basis for follow-up evaluation. BR testing may benefit in the diagnosis of hemifacial spasm, dystonia, functional movement disorders, migraine, orofacial pain, and psychiatric disorders. Although the abnormalities in the integrity of the BR pathway itself may provide information about trigeminal or facial nerve disorders, alterations in BR excitability are found in several disease conditions. BR excitability studies are suitable for understanding the common pathophysiological mechanisms behind various clinical entities, elucidating alterations in top-down inhibitory systems, and allowing for follow-up and quantitation of many neurological syndromes.

Unilateral periocular spasm.

ABSTRACT: Hemifacial spasm is an uncontrollable, recurrent facial muscular contraction that typically occurs on one side of the face, cannot be suppressed, and can last the entire day and during sleep. The most common underlying cause of facial nerve compression is an enlarged or abnormal tracking blood vessel at the brainstem level. Clinical diagnoses are frequently based on a patient's medical history and physical examination. Before deciding on a course of action, however, an electromyogram and MRI are performed to determine the underlying cause. Due to its high effectiveness (success rates of 85% to 95%) and low frequency of adverse reactions, botulinum toxin is the preferred therapy for hemifacial spasm and can provide transient symptomatic alleviation. Surgical microvascular decompression is a therapeutic approach that targets the underlying cause of this condition and has an average success rate of 85%.

[Historical Review of Hemifacial Spasm].

Facial spasm is a disorder characterized by mostly unilateral(hemifacial)involuntary facial muscle contractions, usually caused by vascular compression of the facial nerve. It has been known since ancient times and we can currently find both old medical and artistic presentations. Charles Bell has described at least one definite case(No. IV)with hemifacial spasm in his textbook published in 1830 as did the following physicians like Romberg, Hammond, Gowers, and Brissaud. Babinski coined the name hemispasme facial in 1905 and its English term "hemifacial spasm" appeared in the article by Ehni et al. in 1945. Neurovascular or microvascular decompression surgery was applied to treat this disease in the 1960s and remains a curative therapeutic procedure. Therapy with botulinum toxin appeared as a less invasive procedure in the 1980s and is currently the preferred treatment because of its high safety and efficacy. Secondary facial spasms may occur as a consequence of facial paresis or space-occupying lesion along the facial nerve pathway.

[Prevalences of Trigeminal Neuralgia and Hemifacial Spasm].

Neurosurgeons must have knowledge about the epidemiology of trigeminal neuralgia and facial spasm. The annual incidence of trigeminal neuralgia is 4.3-28.9 per 100,000 persons, with a prevalence of 76.8 per 100,000 persons, increasing with age. It is more common in women and on the right side, with SCA being the most common causative vessel. The long-term efficacy of MVD for trigeminal neuralgia is 80% with complete resolution of pain and 5.2% with complications, which is safe and highly effective when performed by an expert surgeon. Hemifacial spasm has an annual incidence of 0.78/100,000 with a prevalence of approximately 10 per 100,000, increasing with age. It is more common in women and on the left side. AICA alone is the most common causative vessel. The long-term efficacy of MVD for facial spasms is 87.1% with complete resolution of facial spasms and 3.0% with complications. As with trigeminal neuralgia, safe and highly effective treatment can be expected when treated by an expert surgeon.

[Botulinum Toxin Treatment for Hemifacial Spasm:Based on the Practical Clinical Experience in the Neurology Outpatient Clinic].

Botulinum toxin(BTX)treatment is the first-line neurological treatment for hemifacial spasm(HFS). In my neurology clinic, Clinique Kita Neurologique(CKN), I have provided a cumulative total of approximately 400 BTX treatments for approximately 50 HFS patients for 23 years. Based on my own practical clinical experience, I have demonstrated the efficacy of BTX treatment. In compressive HFS, BTX treatment is indicated in patients who are not indicated or unwilling to undergo neurodecompression surgery. This is also indicated in the case of a long waiting period before surgery. In postparetic HFS, BTX treatment is indicated in patients with spasm and synkinesia. The amount of each BTX injection in postparetic HFS should be less than that in compressive HFS because of latent facial paresis. Although BTX injections can be easily administered in neurology outpatient clinics, it is important to perform the procedure safely and promptly.

[Image Diagnosis for Hemifacial Spasm].

Cisternography using heavy T2-weighted images from 3-Tesla magnetic resonance imaging(MRI)and three-dimensional time-of-flight MR angiography(3D TOF MRA)is useful for identifying conflicting vessels in primary hemifacial spasm(HFS). Cisternography provides high-signal images of the cerebrospinal fluid and low-signal images of the cranial nerves and cerebral blood vessels, whereas 3D TOF MRA provides high-signal images with only vascular information. The combination of these two methods increases the identification rate of conflicting vessels. The neurovascular conflict(NVC)site in HFS is where the facial nerve exits the brainstem. However, on MRI, the true NVC site is often more proximal than the facial nerve attachment to the brainstem. On preoperative MRI, it is important to not miss the blood vessels surrounding the proximal portion of the facial nerve. If multiple compression vessels or deep vessels are located in the supraolivary fossette, they may be missed. Coronal section imaging and multiplanar reconstruction(MPR)minimize the chances of missing a compression vessel. Preoperative MRI and CT can also provide various other information, such as volume of the cerebellum, presence of emissary veins, shape of the petrosal bone, and size of the flocculus.

[Trigeminal Neuralgia and Hemifacial Spasm: What to Do If It Does Not Cure?]

Although microvascular decompression(MVD)is a highly effective treatment, there is little pathological evidence and some aspects of its mechanism remain unclear. Therefore, when symptoms appear after surgery, it is difficult to determine the pathological condition and select the treatment method. Therefore, we recommend dividing these factors into three categories. The first is "prolonged cure." Compressed nerves may take time to regenerate; therefore, it is necessary to wait at least one year to see if they recover naturally, especially in facial spasms. The second is "uncured." Intraoperative video and postoperative imaging findings should be reviewed. If a compressed blood vessel is overlooked or inappropriately decompressed, additional surgery should be performed. The third is "true recurrence," which is the loss of fixation of compressed blood vessels and granulomatization of the Teflon. Nerve bending that occurs again due to the retraction of the trigeminal nerve is corrected by reoperation. The therapeutic effects of reoperation are particularly strong in trigeminal neuralgia. Owing to the risk of nerve damage due to adhesion dissection, it is important to carefully consider and establish good communication with patients before surgery.

[Surgical Techniques for Microvascular Decompression in Hemifacial Spasm].

This study discusses the key microvascular decompression(MVD)techniques for the treatment of hemifacial spasm(HFS). The author's experience is based on their institution's cases, highlighting three critical techniques. (1)Vertebral artery(VA)repositioning: Repositioning the VA is essential in challenging cases. This article focuses on the relocation of the proximal portion of the VA and the importance of careful dissection. (2)Relocating vessels compressing the peripheral branches of the facial nerve: HFS can result from nerve compression at various locations, including the cisternal portion. This study addressed cisternal compression and considered the nearby nerves. (3)Considering the perforating branches during repositioning, cases may involve complex branching of the perforating arteries. This paper describes an approach that carefully repositions the vessels without damaging the perforating branches. The results from 100 VA-involved cases showed excellent outcomes, with 91.2% of patients experiencing T0(excellent)results. This study emphasized the need to adapt the surgical approach to each unique case to ensure the safety and effectiveness of MVD. This study provides insights into the critical MVD techniques for HFS, emphasizing the importance of continuous experience and knowledge accumulation. These techniques can be learned by other neurosurgeons, thereby expanding the availability of safe and successful MVD procedures for HFS.

[Microvascular Decompression:The Superiority of Transposition].

In this feature article, we underscore the advantages of Transposition over Interposition in the management of trigeminal neuralgia and hemifacial spasm. Interposition, while effective, has raised concerns owing to long-term complications associated with the use of artificial materials, such as Teflon and silicone sponges. Transposition, on the other hand, mitigates these issues, showcasing adaptability to a range of anatomical and pathological conditions and affirming its standing as a safer and more effective treatment alternative. Each technique has distinct applications that are governed by the patient's specific anatomical and pathological needs. While Transposition is emerging as a favored option, Interposition remains relevant in specific cases, underscoring the necessity for a personalized approach to neurovascular decompression. In offering a comprehensive overview, this article is not just an academic exercise, but also a practical resource. A nuanced exploration of these surgical interventions is meant to provide readers with actionable insights, blending the current findings with real-world applicability. The goal is to foster a deeper understanding and aid practitioners in making informed decisions that are finely attuned to each patient's unique needs and conditions, ensuring optimal outcomes, while prioritizing safety and effectiveness.