Shunting in tuberculous meningitis: a neurosurgeon’s nightmare

Abstract

I read with interest the original paper by Sil et al. entitled “Shunting in tuberculous meningitis: a neurosurgeon’s nightmare” [Childs Nerv Syst (2008) 24:1029–1032]. I am delighted and congratulate the authors on presenting their valuable work on shunting in tuberculous meningitis, which is indeed a difficult decision-making process and associated with a variable outcome. They conclude that early shunting is the best option to prevent long-term neurological sequelae. Tuberculous meningitis still continues to be a grave problem in Indian population at large, especially in children. It frequently forms an important differential diagnosis for childhood chronic meningitis. The sequelae can be devastating and contributes significantly to the economic burden of the family as well as the nation. The CSF diversion procedure is largely based on the Palur’s grading system for tubercular meningitis. In the era prior to effective antitubercular medication, there was a little choice for the clinician apart from a shunt procedure for hydrocephalus. The potential ill effects of shunt infection and a relatively high incidence of repeated shunt blockade have always been worrisome and precluded easy decision making for shunt insertion. Following an effective antitubercular medication and steroids for tubercular meningitis, aggressive neurosurgical intervention was largely avoided and a wait and watch policy was adopted. However, in absence of an objective criterion, the uniformity for cerebrospinal fluid (CSF) diversion procedure is still questionable among neurosurgical fraternity and ranges from close neurological observation to a delayed time interval for CSF diversion procedure. An intellectual indifference and a false sense of security could occur on the part of the clinician which could result in delay for intervention, especially since the symptomatology of meningitis secondary to vasculitis and arachnoiditis versus raised intracranial pressure tend to overlap and/or coexist. There is little controversy about the role of shunt in noncommunicating hydrocephalus in tuberculous meningitis which is confirmed readily on serial imaging. The decision for shunt insertion in communicating hydrocephalus could be difficult and needs to be appropriately measured. The neurosurgeon’s role in tuberculous meningitis is largely restricted to the cerebrospinal fluid diversion procedures as mentioned by the authors. The selection of the patient for cerebrospinal fluid diversion is important for optimal outcome [1, 2]. The outcome of CSF diversion procedure is more gratifying if the timing of intervention is appropriate. The decision to perform a CSF diversion procedure is a sum product of the clinical profile of the patient and radiological imaging. It is a function of time. It requires to be stressed that the clinical history of the patient is paramount. This is reflected by the author’s results in which Palur grade II patients had a better outcome. The moderate hydrocephalus in Palur grades I and II should be closely monitored clinically for the need of possible early intervention to maximize the neurological outcome and prevent potential irreversible morbidity. Nature and homeostatic mechanisms allow a certain time frame for optimal outcome. The neurosurgeon should be Childs Nerv Syst (2008) 24:1383–1384 DOI 10.1007/s00381-008-0741-2