Tuberculous optochiasmatic arachnoiditis and optochiasmatic tuberculoma in Malaysia

Background & Objectives: Arachnoiditis which involves the optic chiasm and optic nervecan rarely occurs in the patients with tuberculous meningitis (TBM). The primary objective of this study was to determine the incidence, assess the clinical and neuroimaging findings, and associations, understand its pathogenesis of these patients, and determine its prognosis. Methods: The patients admitted with TBM in the neurology wards of two tertiary care hospitals from 2009 to 2017 in Kuala Lumpur, Malaysia were screened. The patients with OCA and optochiasmatic tuberculoma were included in this study. We assessed the clinical, cerebrospinal fluid (CSF), imaging findings of the study subjects and compared with other patients without OCA or optochiasmatic tuberculoma. Results: Eighty-eight patients with TBM were seen during the study period. Seven (8.0%) had OCA and one (1.1%) had optochiasmatic tuberculoma. Five out of seven (71.4%) patients with OCA were newly diagnosed cases of TBM. The other two (28.6%) had involvement while on treatment with antituberculous treatment (paradoxical manifestation). The mean age of the patients with OCA was 27.3 +/- 11.7. All the OCA patients had leptomeningeal enhancement at other sites. All had hydrocephalus and cerebral infarcts on brain neuroimaging. Three (42.9%) patients had cerebral tuberculoma at sites other than suprasellar and optic chiasm areas. On univariate analysis, the presence of OCA and optochiasmatic tuberculoma was associated with raised CSF opening pressure (p=0.014), younger age (p=0.024), cerebral infarcts (p=0.018) and hydrocephalus (p=0.046). There was no statistically significant association on logistic regression. Only one (143%) patient had visual impairment. Conclusion: OCA and optochiasmatic tuberculoma were seen in 9% of a cohort of Malaysian TBM patients. They were more likely to be younger, have raised CSF opening pressure, cerebral infarcts and hydrocephalus, suggesting the association with a more severe exudative disease.