[Neuro-infections to be borne in mind].

We presented atypical manifestations in tuberculous meningitis (TbM) and herpes simplex encephalitis (HSE), lymphocytic dominant cerebrospinal fluid pleocytosis in bacterial meningitis, and a hitherto easily overlooked critical illness polyneuropathy (CIP) associated with sepsis. 1) We presented 2 TbM patients with atypical manifestations. One patient was a 25-year-old man who exhibited polymorphonuclear (PMN) dominant pleocytosis in CSF throughout his clinical course. He died the next day after a CSF culture yielded the growth of tuberculous bacilli, before receiving appropriate anti-TBM therapy. This was a rare TbM example of persistent PMN dominant CSF pleocytosis. The other patient was a 39-year-old woman whose CSF pleocytosis changed from lymphocytic dominant to PMN dominant about 1 month after the initiation of antituberculous chemotherapy. This CSF change was followed by multiple cerebral infarcts due to vauculitis caused by TbM. Administration of prednisolone caused marked improvement of the patient's symptomatology. Tuberculomas appeared transiently during anti-TbM therapy, consistent with paradoxical progression of tuberculoma. 2) A few patients with HSE may show atypical CSF findings such as PMN dominant pleocytosis, absence of pleocytosis, and low sugar value. Our national survey of HSE patients showed following percentages of these atypical findings: PMN dominant pleocytosis observed in 10% of the patients in the early stage and at the time of exacerbation, no pleocytosis in 0.9% (1 patient), and low sugar value in 4%. 3) Bacterial meningitis typically causes PMN dominant CSF pleocytosis. However, Listeria meningitis (LM) may cause lymphocytic dominant pleocytosis in 30% of the patients, particularly in elderly ones. We showed one such 69-year-old patient with persistent lymphocytic dominant CSF pleocytosis throughout the clinical course. 4) CIP, septic encephalopathy and critical illness myopathy are 3 major complications associated with sepsis. CIP is a frequent cause of neuromuscular weakness due to axonal dysfunction, which occurs to critically ill patients with sepsis, particularly when multiple organ dysfunctions are present. We showed our CIP patient associated with acute bacterial endocarditis and multiple organ failure. We should bear in mind these atypical manifestations, and frequent and important complications associated with sepsis such as CIP, to provide appropriate management to patients with neuro-infection and sepsis.