Case presentation

A 19-year-old right-handed woman was admitted with a progressive, 10-day history of headache, malaise, fever and dysarthria. The headache was increasingly severe and refractory to analgesia. She experienced phonophobia, photophobia, tinnitus and recurrent vomiting. She had pain in her lower back and legs. She was a student and had been previously healthy. She did not smoke or take recreational drugs and drank little alcohol. She had not travelled abroad in the previous year, but her father was from an area of higher tuberculosis (TB) prevalence. On examination, she was confused and dysarthric but orientated to time and place. Upper limb reflexes were brisk. She was in painful urinary retention.

Urine culture was positive for Escherichia coli. She was started on oral amoxicillin and underwent urethral catheterisation. On day 2 of admission, she developed meningism, opsoclonus and stimulus-sensitive myoclonus. Funduscopy was unsuccessful due to opsoclonus. She had an unusual and worsening speech disorder: her sentences started clearly, then became progressively less intelligible, with overlapping and poorly timed syllables and dyspraxic errors. Her comprehension was preserved. Tone and power were normal throughout, reflexes remained brisk in the upper limbs but diminished in the lower limbs. Plantar responses were flexor. There were no sensory signs. There was bilateral dysmetria and intention tremor and she was severely ataxic.

Question 1: what is the most likely site of the lesion?

The symptoms do not localise to a single lesion. There are meningitic features. Ataxia suggests cerebellar involvement. Dysarthria may localise to several areas: cerebellum, cranial nerve involvement due to meningitis and parenchymal disease in the brainstem or supratentorial regions. Localisation of opsoclonus is incompletely understood but may involve nuclei in the pons or cerebellum.1 Urinary retention localises to spinal cord, conus, cauda equina or peripheral nerves. Limb pain and back pain could represent spinal cord or radicular involvement or reflect systemic upset. This seems …