Infection of the central nervous system with Nocardia sp. usually manifests as supratentorial abscesses. Supratentorial and cerebellar abscesses from infection with Nocardia sp. following immunosuppression with long-term corticosteroids for idiopathic thrombocytopenia (ITP) have not been reported. An 83 years-old, human immunodeficiency virus (HIV)-negative, polymorbid male with ITP for which he required corticosteroids since age 53 years developed tiredness, dyspnoea, hemoptysis, abdominal pain, and progressive gait disturbance. Imaging studies of the lung revealed an enhancing tumour in the right upper lobe with central and peripheral necrosis, multiple irregularly contoured hyperdensities over both lungs, and right-sided pleural effusions. Sputum culture grew Nocardia sp. Neurological diagnostic work-up revealed dysarthria, dysphagia, ptosis, hypoacusis, tremor, dysdiadochokinesia, proximal weakness of the lower limbs, diffuse wasting, and stocking-type sensory disturbances. The neurological deficits were attributed to an abscess in the upper cerebellar vermis, myopathy from corticosteroids, and polyneuropathy. Meropenem for 37 days and trimethoprime-sulfamethoxazole for 3 months resulted in a reduction of the pulmonary, but not the cerebral lesions. Therefore, sultamicillin was begun, but without success. Long-term therapy with corticosteroids for ITP may induce not only steroid myopathy but also immune-incompetence with the development of pulmonary and cerebral nocardiosis. Cerebral nocardiosis may not sufficiently respond to long-term antibiotic therapy why switching to alternative antibiotics or surgery may be necessary.
Adrenal Cortex Hormones/*adverse effects/*therapeutic use ; Aged, 80 and over ; Cerebellar Diseases/*chemically induced/*diagnosis/pathology ; Humans ; Immunosuppression ; Male ; Muscular Diseases/*chemically induced/pathology ; Nocardia Infections/*diagnosis ; Purpura, Thrombocytopenic, Idiopathic/*drug therapy

Cerebellitis is a rarely encountered complication of isoniazid therapy. Its occurrence is usually associated with concomitant renal disease and haemodialysis. Herein, we report the case of a patient with this complication who presented with isolated bilateral symmetrical dentate nucleus T2 hyperintensities on magnetic resonance imaging. Isoniazid neurotoxicity has never been reported to cause bilateral dentate hyperintensities, for which the differentials are few and include metronidazole toxicity.
Adult ; Antitubercular Agents ; adverse effects ; Cerebellar Diseases ; chemically induced ; Cerebellar Nuclei ; pathology ; Diagnosis, Differential ; Female ; Humans ; Isoniazid ; adverse effects ; Magnetic Resonance Imaging ; Renal Dialysis ; Renal Insufficiency ; therapy ; Tuberculosis ; drug therapy