• LEPTOMENINGEAL DISEASE
• PRIMARY TESTICULAR LYMPHOMA
• CSF
• CYTOLOGY
• PET

A previously healthy right-handed 48-year-old man presented initially with a 5-day history of progressive left facial weakness. He was diagnosed with Bell's palsy and discharged home; he fully recovered over 4 weeks. As he presented relatively late, he was not prescribed oral corticosteroids. Six months later, he developed a band of pain radiating around his back that persisted for 2 weeks. There was no radiation down his legs and no bladder or bowel involvement. Several days later he noted lower limb weakness and horizontal diplopia, both of which worsened over 2 months until he re-presented to hospital.

On examination, he had impaired upgaze and adduction of his left eye with diplopia, consistent with a partial left third nerve palsy, although at this point he had no ptosis and his pupils were equal and reactive. There was no other cranial nerve involvement, and upper limb examination was normal. Power was reduced (4/5) in all muscle groups in his legs with absent knee and ankle jerks, flexor plantar responses and distal sensory loss to all modalities.

Nerve conductions studies showed only bilateral carpal tunnel lesions with normal motor and sensory studies. Electromyography (EMG) suggested a nerve root or upper motor neurone problem with regular firing rates in the weak leg muscles. MR scan of brain and whole spine with gadolinium showed diffuse abnormal enhancement throughout intradural leptomeningeal structures. This was particularly evident around the lumbar expansion and conus medullaris, and to a lesser extent around the cervical cord and lower brainstem. Intracranial enhancement was most obvious within bilateral cisternal segments of the oculomotor and trigeminal nerves (figure 1), and within both internal auditory …