Rhabdomyolysis Associated with Severe Levodopa-Induced Dyskinesia in Parkinson's Disease: A Report of Two Cases and Literature Review

Dyskinesia-hyperpyrexia syndrome in Parkinson's disease triggered by overdose of levodopa - a case report and literature review

Dyskinesia-hyperpyrexia syndrome, a rare medical emergency in Parkinson's disease, is first described in 2010. It is characterized by severe continuous dyskinesia associated with rhabdomyolysis, hyperthermia and subsequent alteration of the mental state. Gradual reduction of dopaminergic dose or DBS is recommended treatment. The prognosis is usually good, but sometimes fatal. But so far, this potentially fatal complication is not widely recognized by clinicians. In emergency, if clinicians fail to make prompt diagnosis and treatment, patients' conditions may get worse, and their lives may be threatened in serious cases.

Drug-Induced Movement Disorders

Drug-induced movement disorders (DIMDs) are most commonly associated with typical and atypical antipsychotics. However, other drugs such as antidepressants, antihistamines, antiepileptics, antiarrhythmics, and gastrointestinal drugs can also cause abnormal involuntary movements. Different types of movement disorders can also occur because of adverse drug reactions. Therefore, the important key to diagnosing DIMDs is a causal relationship between potential offending drugs and the occurrence of abnormal movements. The pathophysiology of DIMDs is not clearly understood; however, many cases of DIMDs are thought to exert adverse mechanisms of action in the basal ganglia. The treatment of some DIMDs is quite challenging, and removing the offending drugs may not be possible in some conditions such as withdrawing antipsychotics in the patient with partially or uncontrollable neuropsychiatric conditions. Future research is needed to understand the mechanism of DIMDs and the development of drugs with better side-effect profiles. This article reviews the phenomenology, diagnostic criteria, pathophysiology, and management of DIMDs.

Parkinsonism-Hyperpyrexia Syndrome and Dyskinesia-Hyperpyrexia Syndrome in Parkinson's Disease: Two Cases and Literature Review

Parkinsonism-hyperpyrexia syndrome (PHS) and dyskinesia-hyperpyrexia syndrome (DHS) are rare but exhibit life-threatening complications in Parkinson’s disease (PD). We herein presented two cases of PD patients and performed a comprehensive and comparative literature review for these two syndromes. The first case was diagnosed as PHS with cerebral salt wasting syndrome caused by abrupt withdrawal of antiparkinsonian medication. Her symptoms were gradually remitted with reinstitution of the medication. The second one was an early-stage PD patient diagnosed as DHS in association with abuse of antiparkinsonian drugs. Her symptoms were gradually remitted with reduced dosage of dopaminergic drugs. Results of literature reviews revealed a total of 56 and 13 cases of PHS and DHS, respectively, and they were more likely to occur in elderly and long-term PD patients. These two syndromes showed different female-to-male ratio, similar mortality, and different recovery time. There were stark differences between PHS and DHS, including triggers (abrupt drug stoppage versus drug abuse), symptoms (worsened tremor and rigidity versus continuous dyskinesia), and treatment (drug reinstitution versus drug reduction). In summary, our reports and the review provide new insights into PHS and DHS in association with PD and may facilitate rapid discrimination of the syndromes for timely and proper treatment to reduce mortality.

Entacapone alleviates acute kidney injury by inhibiting ferroptosis

Acute kidney injury (AKI) is a common clinical problem and an efficacious treatment is lacking. Ferroptosis, a newly discovered type of programmed cell death, has been reported to alleviate renal tubular injury in ischemia/reperfusion-induced acute kidney injury (I/R-AKI). Entacapone is a specific inhibitor of catechol-O-methyltransferase, which is used as an adjuvant drug against Parkinson's disease. We demonstrated that entacapone prevents renal I/R injury by inhibiting ferroptosis. Compared with a sham group, entacapone treatment mitigated I/R-induced pathological alterations, improved renal function, and inhibited ferroptosis. In HK-2 cells, entacapone treatment significantly reduced the lipid peroxidation and iron accumulation induced by the ferroptosis inducers erastin and RSL3, and significantly regulated expression of ferroptosis-related proteins. Entacapone upregulates p62 expression and affects the p62-KEAP1-NRF2 pathway, thereby upregulating nuclear translocation of NRF2. This action results in increased expression of the downstream SLC7A11, and significant suppression of oxidative stress and ferroptosis. Our results identify entacapone as a ferroptosis inhibitor that enhances antioxidant capacity. Entacapone may serve as a novel strategy to improve treatment of, and recovery from, I/R-AKI.