Gentamicin-induced Myoclonus

Abstract

AIM, although rare, should be considered as a potential cause of multifocal myoclonus in patients with advanced age or renal insufficiency. The prognosis of AIM appears favorable, with several cases resolving after withdrawal of the antibiotic.

The clinical heterogeneity of drug-induced myoclonus: an illustrated review

“…The presumed anatomic structures and neurotransmitters involved are suggested to differ per causative agent. Drug-induced myoclonus was usually reversible following withdrawal of the offending drug [10, 44], and only a single case of persistent myoclonus has been reported [75]. We here describe the characteristics of myoclonus caused by the four classes of drugs most often reported in relation to myoclonus (opiates, antidepressants, antipsychotics, and antibiotics) and by the group of drugs involved in our case B (NMDA antagonists).…”

“…It is commonly accompanied by other symptoms, such as altered mental state, seizures (similar to our case A), aphasia, chorea, and skin rash [75]. Myoclonus due to β-lactam antibiotics clinically varies from subtle peri-ocular twitching to generalized myoclonus [75]. Myoclonus due to quinolones can be generalized [21, 38] or multifocal [81].…”

“…Antibiotic-induced myoclonus mainly occurs in association with high or toxic doses of antibiotics and/or underlying renal disease [75]. It is commonly accompanied by other symptoms, such as altered mental state, seizures (similar to our case A), aphasia, chorea, and skin rash [75].…”

“…Myoclonus due to quinolones can be generalized [21, 38] or multifocal [81]. It is hypothesized that β-lactam antibiotics selectively antagonize [75] and quinolones completely inhibit [71] gamma aminobutyric acid (GABA) receptors, decreasing their inhibitory activity at nerve terminals, thus inducing a hyperexcitable neuronal state of the central nervous system that triggers myoclonus. Sulfonamides have been associated with multifocal and generalized myoclonus.…”

“…Myoclonus can be classified by distribution (focal, segmental, multifocal, and generalized) [75], by localization of the ‘pulse generator’ (cortical, subcortical, brainstem, spinal, or peripheral) [44], and by aetiology (physiological, essential, epileptic, symptomatic, and psychogenic) [44, 52]. In this paper, we review the phenomenon of drug-induced myoclonus, a subgroup of symptomatic myoclonus, with an emphasis on the clinical and pathophysiological heterogeneity of this phenomenon, which could mislead clinicians and result in insufficient consideration of drugs as the cause of myoclonus.…”