Acute self-limiting cerebellar syndrome is a poorly recognized complication of Mycoplasma pneumoniae infection 1 .
CASE HISTORYA woman aged 60, who 27 years earlier had had her mitral valve replaced with a prosthesis, developed '¯u-like symptoms and a productive cough for which her general practitioner prescribed amoxycillin. On day 6 he found signs of consolidation at the right lung base with continued fever, so clarithromycin was added. She had well-controlled atrial ®brillation and was on warfarin and digoxin; the prosthetic valve was functioning normally.On day 8 the international normalized ratio (INR) was checked and had risen to 8.2. On the advice of a haematologist she was given intravenous vitamin K. Because of concern over the anticoagulation, together with continuing fever, anorexia and persistent signs at the right base, she was admitted to hospital on day 9. On admission the chest X-ray con®rmed right basal consolidation. The INR was 2; clarithromycin was stopped because it was thought to be interfering with anticoagulant control. White cell count showed a slight lymphopenia (0.6610 9 /L). She was treated with intravenous ceftriaxone for 7 days and improved clinically and radiologically. On day 17 she was switched to oral co-amoxiclav and was discharged.On day 18 she was readmitted with relapse of her productive cough, fever and continued anorexia and weight loss. White cell count was 13.7610 9 /L (neutrophils 12.2, lymphocytes 0.4), erythrocyte sedimentation rate was 40 mm/h and C-reactive protein 97 mg/dL. Chest X-ray now showed left basal consolidation with resolution of the right basal consolidation. Increased antibody to M. pneumoniae was detected by the complement ®xation and gelatin particle agglutination tests, con®rmed by the presence of speci®c IgM by enzyme-linked immunosorbent assay in all samples apart from that collected on day 8. No signi®cant antibodies were detected by the complement ®xation test to adenovirus, in¯uenza virus type A, herpes simplex, Coxiella burnetii and/or Chlamydia psittaci, and speci®c IgM to Epstein±Barr virus was absent. Pseudomonas aeruginosa was grown from a sputum sample. She was treated with intravenous ceftazidime and gentamicin and with oral azithromycin.On day 20 she required catheterization for urinary retention and on day 21 she was noted to be very weak with slurred speech and complaining of double vision. Examination revealed bilateral horizontal nystagmus, upbeat nystagmus, slurring dysarthria, bilateral upper and lower limb ataxia and bilateral dysdiadochokinesis; the central and peripheral nervous systems were otherwise normal. A computed tomographic head scan and magnetic resonance imaging of the brain and cerebellum showed nothing abnormal. Thyroid function tests were normal. C-reactive protein peaked at 135 mg/dL. A lumbar puncture was not done because it seemed unlikely to help diagnostically and her INR was 4.6. On day 22 she no longer exhibited dysdiadochokinesis and on day 24 her nystagmus was less pronounced and she was able to walk aided....