Negative myoclonus as the leading symptom in acute cefepime neurotoxicity

An 86-year-old woman was diagnosed with hospital-acquired pneumonia with Pseudomonas aeruginosa and treated with cefepime adjusted to her renal clearance. After 4 days, she developed acute-onset negative myoclonus without signs of altered mental status. After ruling out an acute intracranial haemorrhagic or ischaemic stroke as well as other metabolic and endocrine causes of negative myoclonus, the antibiotic was switched to piperacillin/tazobactam due to a suspicion of cefepime neurotoxicity. The patient improved within 24 hours and her symptoms fully resolved within 4 days. These observations suggest a link of the negative myoclonus to acute cefepime neurotoxicity, which may occur without or with minimal alteration of mental status, thus extending its spectrum of clinical presentation.

Role of high-density EEG (hdEEG) in pre-surgical epilepsy evaluation in children: case report and review of the literature

Introduction Electrical source imaging (ESI) and especially hdEEG represent a noninvasive, low cost and accurate method of localizing epileptic zone (EZ). Such capability can greatly increase seizure freedom rate in surgically treated drug resistant epilepsy cases. Furthermore, ESI might be important in intracranial record planning. Case report We report the case of a 15 years old boy suffering from drug resistant epilepsy with a previous history of DNET removal. The patient suffered from heterogeneous seizure semiology characterized by anesthesia and loss of tone in the left arm, twisting of the jaw to the left and dysarthria accompanied by daze; lightheadedness sometimes associated with headache and dizziness and at a relatively short time distance negative myoclonus involving the left hand. Clinical evidence poorly match scalp and video EEG monitoring thus requiring hdEEG recording followed by SEEG to define surgical target. Surgery was also guided by ECoG and obtained seizure freedom. Discussion ESI offers an excellent estimate of EZ, being hdEEG and intracranial recordings especially important in defining it. We analyzed our results together with the data from the literature showing how in children hdEEG might be even more crucial than in adults due to the heterogeneity in seizures phenomenology. The complexity of each case and the technical difficulties in dealing with children, stress even more the importance of a noninvasive tool for diagnosis. In fact, hdEEG not only guided in the presented case SEEG planning but may also in the future offer the possibility to replace it.

A Case of Myoclonic Epilepsy Presenting with Status Epilepticus in an Elderly Male Patient

Myoclonic epilepsy in the form of status epilepticus is an extremely rare reported presentation. Herein, we describe an 87-year old male patient presenting with abrupt-onset rhythmic myoclonic jerks that were evaluated as synchronous positive and negative myoclonus. Further etiological investigations revealed that the myoclonus was associated with ictogenesis, and appropriate antiepileptic treatment provided total cessation of the movements. To my knowledge, this is a unique case of myoclonic status epilepticus in an elderly patient, which may have been associated with a cerebrovascular disease. In the presentation of this case, we will review the related literature and discuss some considerations to explain the pathophysiology of epileptic myoclonic movements and the possible role of pontine lesions.

Myoclonus

Myoclonus is defined as brisk, shock-like, involuntary movements. Hiccup and nocturnal myoclonus are physiological myoclonus. Myoclonus is usually caused by abrupt, instantaneous contraction of muscles (positive myoclonus), but it can be also caused by transient interruption of the ongoing muscle contraction (negative myoclonus, asterixis). Myoclonus is usually irregular, but some myoclonus may occur at certain intervals (rhythmic or periodic myoclonus). Myoclonus is caused by excessive excitation of motor neurons in the motor cortex (cortical myoclonus, epileptic myoclonus), in the brainstem, or in the spinal cord (spinal myoclonus). Cortical myoclonus is commonly associated with convulsive seizures and is also called epileptic myoclonus. Syndromes characterized by myoclonus, generalized convulsion, and cognitive impairment are coined the progressive myoclonus epilepsies and are caused by multiple neurodegenerative diseases.