Piriformis syndrome is a rare cause of sciatica, which results in low backache due to sciatic nerve Dentate nucleus, the largest deep nucleus of the cerebellum, is affected by numerous conditions, including leukodystrophies, toxins, drugs, infections, and various metabolic and inflammatory conditions. This case report is a drug‑induced cerebellitis, caused by isoniazid (INH), characterized in magnetic resonance imaging (MRI) as bilateral dentate nuclei hyperintensity. Isoniazid, an antituberculosis therapy (ATT) drug, is both neurotoxic and hepatotoxic but cerebellitis is a rare complication. INH‑induced cerebellitis is characterized in MRI by bilateral and symmetrical T2/fluid‑attenuated inversion recovery (FLAIR) hyperintensity in dentate nuclei. Though metronidazole is the most common drug associated with such MRI signal changes in the dentate nucleus, the uncommon association with INH has been described in literature especially in patients with renal function impairment. MRI findings together with clinical signs of cerebellar involvement, in a patient with abnormal renal function tests and in whom the ATT regimen was recently initiated, favors the diagnosis of INH toxicity. INH withdrawal and pyridoxine supplementation can reverse this condition.
Keywords: : Dentate nucleus hyperintensity; drug‑induced cerebellitis; isoniazid neurotoxicity
Introduction
The dentate nucleus is the largest deep cerebellar nuclei and is affected by many benign and potentially treatable conditions with favorable prognosis.[1] Metronidazole is the most common cause for drug‑induced cerebellitis, affecting the bilateral dentate nuclei.[1] In developing countries
where tuberculosis (TB) is prevalent, isoniazid (INH) an antituberculosis drug, induced cerebellitis, though rare,[2] is a possible condition to be aware of.