European Journal of Cardiovascular Medicine

Myeloneuropathies, disorders affecting both the spinal cord and peripheral nerves simultaneously [1], present with a variety of clinical symptoms. These include walking difficulties, weakness in the lower limbs, ataxic gait, and sensory disturbances in a glove and stocking distribution. Physical examination typically reveals myelopathic signs such as hyperreflexia, spasticity, extensor plantar responses, and sometimes bladder and bowel dysfunction. The Romberg sign, indicative of posterior column involvement, is also often noted. Neuropathic signs typically include sensory loss in a glove and stocking pattern, diminished or absent ankle reflexes, and muscle wasting in the distal limbs[2,3].

Symptoms like unsteady gait, varying limb weakness, bladder and bowel issues, and different sensory symptoms could point to myelopathy. However, it's important to note that these symptoms can also coexist in peripheral neuropathy cases[4]. Therefore, conducting a thorough neurological examination and detailed diagnostic evaluation is crucial for the accurate diagnosis of myeloneuropathy.

Long-standing peripheral neuropathy can lead to permanent morphological changes in the foot, such as pes cavus or hammer toes, often seen in hereditary peripheral neuropathies[5]. Identifying subtle signs of peripheral neuropathy becomes challenging when upper motor neuron signs are predominant. In cases with prominent myelopathic features, significantly reduced ankle deep-tendon reflexes and atrophy in the distal lower limbs may be key indicators of concurrent peripheral neuropathy[6]. Additionally, myelopathic signs might be masked by more pronounced lower motor neuron symptoms[1].

This article reports on the etiological profile of myeloneuropathy observed in a tertiary care hospital in Northeast India

OBJECTIVE

The objective of the study was to determine the etiological profile of patients diagnosed with myeloneuropathy.

This prospective observational study was carried out on a cohort of patients admitted with myeloneuropathy to the Neurology Ward and Allied Departments of Gauhati Medical College and Hospital, Guwahati, Assam, India. The study spanned from November 2021 to October 2023. The inclusion criteria for the study were patients diagnosed with myeloneuropathy based on clinical and diagnostic criteria. A total of 14 patients were included in the study, providing a comprehensive sample for analysis.

The methodology involved an extensive array of diagnostic procedures. In addition to routine blood tests, which included assessments of vitamin B12, folate, and copper levels, patients underwent a series of diagnostic investigations. These encompassed chest X-rays and urinalysis, which provided crucial insights into underlying systemic conditions that might contribute to the myeloneuropathy. Nerve conduction studies were conducted to evaluate the function of peripheral nerves, offering essential data on the extent and nature of neuropathy.

Moreover, advanced imaging techniques were employed, including MRI scans of the brain and spinal cord. These imaging modalities played a pivotal role in detecting structural and pathological changes that could be contributing to the myeloneuropathy. Cerebrospinal fluid analysis was another key component of the investigation, aiding in the identification of infectious, inflammatory, or demyelinating processes that might be at play. Additionally, an extensive immunological, infectious, and metabolic profile was obtained for each patient, based on the pattern of involvement observed. This comprehensive approach ensured a thorough evaluation of each case, facilitating an in-depth understanding of the various etiologies underlying myeloneuropathy in this patient population.

Throughout the study, patients who did not meet the diagnostic criteria for myeloneuropathy were excluded to maintain the specificity of the research findings. The study's design and methodology aimed at providing a detailed and accurate etiological profile of myeloneuropathy, contributing valuable insights to the existing literature on this complex neurological condition.

Our study had a total of 14 patients (8 men and 6 women) who presented with myeloneuropathy of different etiologies (Vitamin B12 and Folate deficiencies, Hashimoto’s disease, Chronic liver disease, Neurosarcoidosis, HIV and Unknown).

In the study, the etiological findings were diverse among the 14 patients diagnosed with myeloneuropathy. The most common cause identified was Vitamin B12 deficiency, accounting for 6 cases or 42.8% of the patient population. This highlights the significant role that Vitamin B12 deficiency plays in the development of myeloneuropathy. Folate deficiency was another contributing factor, though less common, identified in 1 patient, making up 7.1% of the cases. Similarly, HIV was found to be the etiological factor in 1 patient, also representing 7.1% of the cases. Chronic liver disease was observed as a cause in a slightly higher proportion of patients, with 2 cases accounting for 14.2% of the total. Neurosarcoidosis and Hashimoto’s disease each were identified as the cause in 1 patient, comprising 7.1% of the cases individually. Interestingly, there were 2 cases, equivalent to 14.2% of the total, where the etiology remained unknown, indicating the complexity and diagnostic challenges associated with myeloneuropathy. These findings underscore the varied etiological spectrum of myeloneuropathy and the importance of considering a broad range of potential causes when diagnosing and treating this condition.

The prevalence of Vitamin B12 deficiency (42.8%) as a leading cause in our study echoes the findings of similar studies. A study by Healton et al. [7] noted that Vitamin B12 deficiency accounts for a significant proportion of myeloneuropathy cases, emphasizing the need for routine screening in at-risk populations. The correlation between Vitamin B12 deficiency and myeloneuropathy has been well-established, with deficiencies leading to neurological manifestations due to demyelination in the spinal cord and peripheral nerves.

Folate deficiency, identified in 7.1% of our cases, is less commonly reported as a primary etiology in the literature. This contrasts with a study by Reynolds [8], which suggested a higher prevalence of folate-related myeloneuropathy, particularly in regions with poor dietary folate intake. The discrepancy could be attributed to geographical variations in diet or differences in study populations.

HIV, causing 7.1% of the cases in our study, aligns with the findings of Maritz et al. [9], where HIV was identified as a significant factor in myeloneuropathy, especially in populations with a high prevalence of HIV. The neurotropic nature of the virus contributes to a spectrum of neurological disorders, including myeloneuropathy.

Chronic liver disease was noted as an etiology in 14.2% of our patients. This is slightly higher compared to a study by Montagnese et al. [10], which reported a lower incidence. This variation could be reflective of regional differences in the prevalence of liver disease and its complications.

Neurosarcoidosis and Hashimoto’s disease, each accounting for 7.1% of cases in our study, are less frequently reported in the literature. A study by Pawate et al. [11] found a lower prevalence of neurosarcoidosis in myeloneuropathy, suggesting that our findings might indicate a unique demographic or genetic predisposition in our patient population.

The unknown etiologies in 14.2% of our cases highlight the challenges in diagnosing myeloneuropathy, as echoed by Flanagan et al. [12], who reported a similar proportion of idiopathic cases. This underlines the need for ongoing research and advanced diagnostic modalities to better understand and identify the underlying causes of myeloneuropathy.

In summary, our study contributes to the understanding of myeloneuropathy etiologies, with a notable prevalence of Vitamin B12 deficiency. It also highlights the importance of considering a range of potential causes, including less common etiologies such as Neurosarcoidosis and Hashimoto’s disease, and the need for comprehensive diagnostic approaches in cases with unknown etiology

This study conducted in a tertiary care hospital in Northeast India offers a crucial insight into the etiological diversity of myeloneuropathy, a complex neurological disorder. The findings indicate that Vitamin B12 deficiency is the most prevalent cause, identified in nearly half of the cases (42.8%). This high prevalence highlights the critical role of nutritional deficiencies in the pathogenesis of myeloneuropathy and underscores the importance of considering dietary history and nutritional assessment in patient evaluations.

The study also reveals the involvement of various other etiological factors. Chronic liver disease, responsible for 14.2% of the cases, suggests a link between systemic organ dysfunction and neurological manifestations. The presence of HIV in 7.1% of cases reflects the neurotropic nature of the virus and its impact on the nervous system. Similarly, autoimmune conditions like Neurosarcoidosis and Hashimoto’s disease, each accounting for 7.1% of the cases, emphasize the need for an autoimmune workup in myeloneuropathy.The identification of Folate deficiency in 7.1% of patients further underlines the importance of comprehensive nutritional evaluation. The remaining 14.2% of cases with unknown etiology highlight the diagnostic challenges and the need for advanced investigative modalities in myeloneuropathy.

In conclusion, the study underscores the necessity for a multidimensional diagnostic approach in myeloneuropathy, considering a range of potential etiologies from nutritional deficiencies to infectious and autoimmune disorders. This comprehensive understanding is crucial for the development of targeted therapeutic strategies and improving patient outcomes.

1. Garg RK, Malhotra HS, Kumar N. Approach to a case of myeloneuropathy. Ann Indian Acad Neurol. 2016;19(2):183-7.
2. Goodman BP. Diagnostic approach to myeloneuropathy. Continuum (Minneap Minn). 2011;17(5 Neurorehabilitation):744-60.
3. Kumar N. Metabolic and toxic myelopathies. Semin Neurol. 2012;32(2):123-36.
4. Herrera Herrera I, Garrido Morro I, Guzmán de Villoria Lebiedziejewski J, Ordoñez González C, Rovira À. Clinical-radiological approach to nontraumatic myelopathy. Radiologia (Engl Ed). 2020;62(6):464-80.
5. Fink JK. Hereditary myelopathies. Continuum (N Y). 2008;14(1):58-74.
6. Goodman BP, Bosch EP, Ross MA, Hoffman-Snyder C, Dodick DD, Smith BE. Clinical and electrodiagnostic findings in copper deficiency myeloneuropathy. J Neurol Neurosurg Psychiatry. 2009;80(5):524-7.
7. Healton EB, Savage DG, Brust JC, Garrett TJ, Lindenbaum J. Neurologic aspects of cobalamin deficiency. Medicine (Baltimore). 1991;70(4):229-45.
8. Reynolds EH. Folate deficiency and neurological disease. Clin Neurol Neurosurg. 2006;108(5):407-15.
9. Maritz J, Benatar M, Dave JA, Harrison TB, Badri M, Levitt NS, Heckmann JM. HIV- associated myelopathies. J Neurovirol. 2018;24(4):411-23.
10. Montagnese S, Amodio P, Morgan MY. Hepatic encephalopathy: a neurochemical, neuroanatomical, and neuropsychological study. J Hepatol. 2004;40(2):165-74.
11. Pawate S, Moses H, Sriram S. Neurosarcoidosis: Clinical manifestations, diagnosis and treatment. Pract Neurol. 2013;13(3):176-88.