Neurological manifestations of scrub typhus

To evaluate the neurological manifestations of scrub typhus and correlate their clinical, EEG and MRI findings.

A cross-sectional study over 2 years included patients with scrub typhus diagnosed by solid phase immunochromatographic assay or Weil-Felix test. A detailed clinical evaluation including Glasgow Coma Scale (GCS) was documented. Blood counts, chemistry, ECG, chest radiograph, cerebrospinal fluid (CSF), EEG and cranial MRI were performed. Outcome on discharge and at 1 month were categorised into good and poor based on modified Rankin Scale.

Thirty-seven patients with ages ranging between 3 and 71 years were included; 51% of whom were females. All patients had fever and myalgia. Thirty-one (84%) patients had impaired consciousness, and six were deeply comatose (GCS score ≤8). Eight patients presented with status epilepticus. MRI revealed meningeal enhancement in only 1/25 (4%) patient and EEG showed generalised slowing in 6/28 (21.4%). Among 31 patients with altered sensorium, CSF studies were conducted on 28. Nineteen patients had meningoencephalitis and 9 encephalopathy, but no significant differences were observed in clinical, laboratory, EEG and MRI findings. All patients responded within 48 h to doxycycline and had good recovery at 1 month. Patients with low GCS score had significantly more focal neurological deficit (r=0.5; p=0.002), longer hospital stay (r=-0.4; p=0.03) and more disability on discharge (r=-0.4; p=0.01).

Meningoencephalitis/encephalopathy may be seen in two-third of patients with scrub typhus. Scrub typhus should be included in the differential diagnosis of febrile encephalopathy.