Vasculitic neuropathy (VN) is a distinctive manifestation of peripheral nerve injury caused by inflammation of the vasa nervorum, leading to ischemia and axonal degeneration. It can occur either as part of systemic vasculitic syndromes such as polyarteritis nodosa (PAN), eosinophilic granulomatosis with polyangiitis (EGPA), microscopic polyangiitis (MPA), or as an isolated condition termed non-systemic vasculitic neuropathy (NSVN) (Collins et al., 2010; Kerasnoudis et al., 2016) [1,2]. Clinically, VN often presents with acute or subacute painful asymmetric sensorimotor deficits, classically producing mononeuritis multiplex, although confluent asymmetric polyneuropathy can also be observed (Davies et al., 2016; Collins et al., 2019) [3,4].

The pathological hallmark of VN is necrotizing vasculitis of epineurial vessels with transmural inflammatory infiltrates and fibrinoid necrosis, which results in ischemic nerve fiber loss (Collins et al., 2010; Krarup et al., 2011) [1,5]. Early diagnosis is essential because delayed recognition often leads to irreversible axonal damage and long-term disability (Said and Lacroix, 2005; Sommer et al., 2008) [6,7].

Therapeutic advances, particularly the use of corticosteroids and immunosuppressive agents such as cyclophosphamide, azathioprine, or mycophenolate mofetil, have improved survival and neurological outcomes (Collins et al., 2010; Vital et al., 2014) [1,8]. Nonetheless, residual disability remains a major concern, as studies suggest that between 20–40% of patients continue to experience significant functional limitations despite treatment (Davies et al., 2016; Collins et al., 2019; Vital et al., 2014) [3,4,8].

Long-term outcome assessment requires standardized evaluation tools. The Medical Research Council (MRC) sum score and Neuropathy Impairment Score (NIS) are commonly used to quantify neurological deficits, while the Overall Disability Sum Score (ODSS) is a validated instrument to assess functional disability (Merkies et al., 2002; van Nes et al., 2011) [9,10]. Although international cohorts have reported significant neurological recovery with immunosuppressive therapy, variability in remission rates and persistence of disability remain unresolved issues (Collins et al., 2019; Kerasnoudis et al., 2016) [2,4].

There is a paucity of Indian data addressing long-term disability outcomes in vasculitic neuropathy. Given the heterogeneity in disease presentation, treatment accessibility, and follow-up patterns in resource-limited settings, systematic evaluation of neurological and functional outcomes is essential. This study was therefore undertaken to prospectively evaluate long-term neurological recovery and disability scoring in treated vasculitic neuropathy patients at a tertiary care hospital in Maharashtra.

Study Design and Setting

This was a prospective observational study conducted in the Department of Medicine, at a Tertiary Care Hospital, Maharashtra, from November 2023 to October 2024.

Sample Size and Selection

A total of 60 patients fulfilling the diagnostic criteria for vasculitic neuropathy were included.

Inclusion Criteria:

• Age ≥18 years
• Clinical features suggestive of vasculitic neuropathy confirmed by nerve biopsy or supportive clinical, electrophysiological, and laboratory findings
• Initiation of standardized immunosuppressive therapy

Exclusion Criteria:

• Neuropathy due to diabetes, chronic alcohol use, toxin exposure, hereditary neuropathies
• Patients lost to follow-up within the study period

Data Collection

Baseline data included demographics, clinical profile, nerve conduction studies, and laboratory investigations (autoantibodies, inflammatory markers, renal and liver function).

Treatment Protocol

All patients received high-dose corticosteroids with gradual taper. Additional immunosuppressive therapy (cyclophosphamide, azathioprine, or mycophenolate mofetil) was given based on disease severity, systemic involvement, and treating physician’s discretion.

Outcome Measures

• Neurological function: Medical Research Council (MRC) sum score and Neuropathy Impairment Score (NIS)
• Disability: Overall Disability Sum Score (ODSS)
• Assessments were conducted at baseline, 6 months, and 12 months.

Statistical Analysis

Data were analyzed using SPSS v26. Continuous variables were expressed as mean ± standard deviation. Paired t-tests and repeated-measures ANOVA were applied to assess changes over time. A p-value <0.05 was considered statistically significant.

A total of 60 patients with vasculitic neuropathy were enrolled in the study and followed up for 12 months. The analysis included baseline demographic characteristics, clinical presentations, electrophysiological patterns, treatment regimens, and longitudinal outcome measures.

Table 1. Baseline Demographic and Clinical Characteristics of Patients with Vasculitic Neuropathy

Values are expressed as mean ± SD or percentages, as appropriate. PAN = Polyarteritis nodosa; EGPA = Eosinophilic granulomatosis with polyangiitis; NSVN = Non-systemic vasculitic neuropathy.

Table 2. Electrophysiological Findings at Baseline

Nerve conduction studies were performed in all patients at baseline. Majority showed axonal involvement consistent with ischemic injury.

Table 3. Treatment Modalities Administered

Initial therapy included high-dose corticosteroids (prednisolone 1 mg/kg/day) tapered over 6 months. Immunosuppressive choice depended on systemic involvement and physician’s discretion.

Table 4. Neurological Outcome Measures at Baseline, 6 Months, and 12 Months

*p-values based on repeated measures ANOVA. NIS = Neuropathy Impairment Score; MRC = Medical Research Council; ODSS = Overall Disability Sum Score.

Table 5. Clinical Outcomes at 12 Months

Clinical remission defined as stabilization of neuropathy with minimal or no disability (ODSS ≤ 2). Relapses were predominantly seen in patients with systemic vasculitis.

Figure 1. Trend of Neuropathy Impairment Score (NIS) over 12 months in patients with vasculitic neuropathy (n=60). Error bars represent ± SD. A significant reduction in NIS was observed at 6 months and 12 months compared to baseline (p<0.05).

Figure 2. Trend of Medical Research Council (MRC) sum score over 12 months in patients with vasculitic neuropathy (n=60). Error bars represent ± SD. A significant improvement in motor strength was noted across follow-ups (p<0.05).

Figure 3. Trend of Overall Disability Sum Score (ODSS) over 12 months in patients with vasculitic neuropathy (n=60). Error bars represent ± SD. Progressive functional improvement was documented at 6 months and 12 months compared to baseline (p<0.05).

Figure 4. Line graph showing the distribution of clinical outcomes at 12 months. The percentage of patients achieving complete remission (ODSS ≤ 2), partial improvement, persistent disability (ODSS ≥ 4), and relapse is plotted. Partial improvement was the most common outcome, while relapse was the least frequent.

This prospective study evaluated long-term neurological outcomes and disability scoring in patients with vasculitic neuropathy treated with standardized immunosuppressive regimens at a tertiary care hospital in Maharashtra. Over a 12-month follow-up, patients demonstrated significant neurological recovery and functional improvement, although a subset continued to experience residual disability.

Neurological Recovery

Our findings showed marked improvement in neurological function, with mean NIS decreasing from 48.6 to 29.3 and MRC sum scores improving significantly at 12 months. This aligns with international studies reporting that timely immunosuppression can halt disease progression and promote recovery of nerve function (Collins et al., 2010; Vital et al., 2014) [1,2]. The pattern of improvement was most pronounced during the first 6 months, suggesting that the initial treatment phase plays a critical role in determining long-term neurological outcomes.

Axonal regeneration in vasculitic neuropathy is often incomplete because ischemic injury causes irreversible fiber loss (Krarup et al., 2011; Sommer et al., 2008) [3,4]. Therefore, while clinical recovery is evident, electrophysiological abnormalities may persist. This underscores the importance of early recognition and aggressive treatment to prevent permanent deficits.

Disability Outcomes

The reduction in ODSS from 5.1 at baseline to 2.8 at 12 months highlights significant functional recovery. Similar trends have been reported in European cohorts, where structured immunosuppressive therapy led to sustained improvements in disability indices (Merkies et al., 2002; Collins et al., 2019) [5,6]. Despite this, 13% of our patients continued to have persistent disability (ODSS ≥ 4). This proportion is consistent with earlier reports suggesting that 15–30% of patients retain functional limitations due to irreversible ischemic axon loss (Said and Lacroix, 2005; Davies et al., 2016) [7,8].

The disparity between neurological improvement and residual disability emphasizes that outcome measures must go beyond electrophysiological recovery and include validated disability scores. The use of ODSS in our study provided a practical and reproducible tool for quantifying functional impairment, supporting its routine application in both research and clinical follow-up (van Nes et al., 2011) [9].

Relapse and Prognostic Factors

In our study, relapses occurred in 8% of patients, predominantly in those with systemic vasculitis. Prior studies have similarly observed higher relapse rates in systemic vasculitic neuropathies compared to NSVN, likely reflecting ongoing systemic immune activity (Collins et al., 2010; Kerasnoudis et al., 2016) [1,10]. Patients with NSVN generally have a better prognosis, with lower relapse rates and higher chances of complete remission (Collins et al., 2019) [6]. Our findings support this trend, as NSVN cases showed more sustained improvements in both neurological and disability scores.

Factors influencing prognosis include early initiation of therapy, extent of axonal loss, and presence of systemic disease (Vital et al., 2014; Davies et al., 2016) [2,8]. Patients presenting late in the disease course or with advanced systemic involvement are more likely to retain residual disability. This highlights the necessity of early recognition and nerve biopsy in atypical neuropathies to establish diagnosis before irreversible damage occurs.

Comparison with Literature

Our remission rate of 32% parallels outcomes from European and Japanese cohorts where remission ranged between 25–40% at one year (Said and Lacroix, 2005; Collins et al., 2019) [7,6]. Similarly, the relapse rate of 8% was slightly lower than reported in Western literature, possibly due to uniform corticosteroid initiation in our cohort and stringent follow-up protocols. Nonetheless, the persistence of disability in a subset of patients highlights the chronic sequelae of vasculitic nerve injury, consistent with earlier reports (Sommer et al., 2008; Krarup et al., 2011) [3,4].

Clinical Implications

This study contributes important data from an Indian tertiary care setting, where long-term follow-up of vasculitic neuropathy is rarely reported. The significant reduction in both neurological and disability scores underscores the effectiveness of immunosuppressive regimens in our cohort. However, the persistence of functional disability in a proportion of patients emphasizes the need for multidisciplinary management, including physiotherapy and occupational rehabilitation.

Moreover, systematic disability scoring using validated tools like ODSS should be incorporated into routine clinical practice. Such structured monitoring not only provides objective outcome measures but also assists in identifying patients at risk for poor recovery who may benefit from intensified therapy.

This prospective study demonstrates that patients with vasculitic neuropathy show substantial neurological recovery and functional improvement over one year of immunosuppressive therapy. Significant reductions were observed in NIS and ODSS, with more than two-thirds of patients achieving either complete or partial remission. However, a subset continued to experience persistent disability, particularly those with systemic vasculitis or delayed presentation. Relapse rates remained low but were more frequent in systemic disease.

These findings highlight the importance of early recognition, prompt initiation of immunosuppressive therapy, and structured long-term follow-up using standardized disability scores to optimize outcomes. Integration of supportive measures such as physiotherapy and rehabilitation is crucial for minimizing residual disability. Future multicenter studies with longer follow-up are warranted to better define relapse patterns, prognostic factors, and the role of newer biologic therapies in improving long-term outcomes.

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