Herpes simplex I encephalitis presenting as a brain haemorrhage with normal cerebrospinal fluid analysis: a case report.

Introduction: Herpes simplex encephalitis is a potentially lethal infection that should be recognised as soon as possible. The combination of clinical history and examination, brain computed tomography or magnetic resonance imaging and lumbar puncture has been used to establish a diagnosis.

Case Presentation: We present a patient who had a suggestive history but a totally normal lumbar puncture and only evidence of intracerebral haemorrhage in the brain magnetic resonance imaging. Diagnosis was made by using the cerebrospinal fluid polymerase chain reaction for herpes simplex virus.

Conclusion: Herpes simplex encephalitis is being increasingly diagnosed with the availability of new diagnostic techniques. Herpes simplex encephalitis can present with the combination of haemorrhage and normal cerebrospinal fluid. Awareness of this common but, if left untreated, devastating condition should increase.