Isoniazid: A rare drug-induced cause for bilateral dentate nuclei hyperintensity

Abstract

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.

A Case of Isoniazid‐Induced Cerebellar Syndrome

“…Magnetic resonance imaging (MRI) revealed symmetric hyperintensities in both dentate nuclei on diffusion‐weighted, T 2 , and fluid‐attenuated inversion recovery sequences (Fig. 1), consistent with isoniazid‐induced cerebellitis 1 . Isoniazid was stopped, with complete resolution of his symptoms and signal changes on MRI 1 month later.…”

Isoniazid-Induced Cerebellitis in a Chronic Kidney Disease Patient

“…Cerebellitis, or inflammation involving the cerebellum, has several etiologies, including various pathogens, autoimmune disorders, or drugs like metronidazole or isoniazid 5 . In association with isoniazid, so far, cerebellitis has only been reported in known cases of renal impairment 11,12 . Diagnosis of cerebellitis requires MRI brain and CSF examination to narrow down and eliminate the differential diagnoses.…”

“…5 In association with isoniazid, so far, cerebellitis has only been reported in known cases of renal impairment. 11,12 Diagnosis of cerebellitis requires MRI brain and CSF examination to narrow down and eliminate the differential diagnoses.…”

Reversible Signal Abnormalities in Bilateral Dentate Nuclei Secondary to Isoniazid Neurotoxicity

“…Eighteen days after cessation of isoniazid, her exam returned to baseline, and MRI demonstrated resolution of the abovementioned signal changes (Figure 1D, Figure 1E, Figure 1F). Seizure, abnormal cerebellar exam, and bilateral dentate nuclei lesions on MRI may reflect reversible manifestations of supratherapeutic isoniazid [1].…”