TRIPPED UP BY AN UNUSUAL DIAGNOSIS?

Case History A 62–year–old man presented with a 3–month history of increasing daytime somnolence, unsteadiness, falls, tremor and amnesia. For the last 3 years he had been immunosuppressed with prednisolone and azathioprine due to suspected Sjögren's disease with positive anti–Ro antibodies and raised ESR. The azathioprine was stopped 4 months prior to admission as there was some doubt of the diagnosis of Sjögren's. He had a pituitary macroadenoma and had recently been started on the dopamine agonist Carbergoline. He was born in Sierra Leone but had lived in the UK for the last 41 years, his last visit to Africa being 29 years ago. Examination/Initial Investigations On examination he was orientated; profoundly bradyphrenic; Parkinsonian and had slowed horizontal saccades. There was mild right–sided facial weakness but no limb weakness or signs of ataxia or neuropathy. He had a normocytic anaemia and thrombocytopaenia. Voltage–gated–potassium channel antibody (VGKC Ab) and n–methyl–d–aspartate receptor antibody (NMDAR Ab) titres were markedly elevated. MRI brain showed grey and white matter abnormalities including bilateral signal change in the substantia nigra. The were radiolucent lesions in the skull. Cerebrospinal fluid (CSF) analysis showed 250 lymphocytes/mm3, protein of 0.57 g/l and a glucose of 4.7 mmol/l. Progression 3 months after admission he was stuporose and having frequent generalised tonic–clonic seizures. At this time results from the bone marrow, undertaken because of pancytopaenia, became available and revealed trypanosomes, pathognomic for human African trypanosomiasis (CSF PCR later confirmed the species as Trypanosoma brucei gambiense). The patient was then transferred for urgent treatment and management at the Hospital for Tropical Diseases. He received nifurtimox and eflornithine combination treatment for the trypanosomiasis and two courses of plasma exchange for persistently elevated VGKC Ab titres. He was discharged home 3 months later, with resolution of the Parkinsonism and significant cognitive and functional improvement. Discussion West African trypanosomiasis (“African sleeping sickness”) is caused by the protozoa Trypanosoma brucei gambiense. Neurological symptoms, characterised by increasing somnolence and cognitive disturbance, manifest during stage II of the disease when the parasite invades the central nervous system. Stage II disease is generally fatal if left untreated. We believe that this case demonstrates the longest