Hiccups in Parkinson's disease: an overlooked non-motor symptom?

An Unusual Cause of Intractable Hiccups

Hiccups are a minor nuisance for most people and usually resolve within minutes. However, for some, they can persist for years and result in severe symptoms and even death. This case report describes a patient found to have a mediastinal lipoma resulting in intractable hiccups. The discussion highlights the pathophysiology, etiologies, and treatments of hiccups.

Risk Factors for Hiccups after Deep Brain Stimulation of Subthalamic Nucleus for Parkinson's Disease

Background: After deep brain stimulation (DBS), hiccups as a complication may lead to extreme fatigue, sleep deprivation, or affected prognosis. Currently, the causes and risk factors of postoperative hiccups are unclear. In this study, we investigated the risk factors for hiccups after DBS of the subthalamic nucleus (STN) for Parkinson’s disease (PD) under general anesthesia. Methods: We retrospectively included patients who underwent STN DBS in the study, and collected data of demographic characteristics, clinical evaluations, and medications. According to the occurrence of hiccups within seven days after operation, the patients were divided into a hiccups group and non-hiccups group. The potentially involved risk factors for postoperative hiccups were statistically analyzed by logistic regression analysis. Results: A total of 191 patients were included in the study, of which 34 (17.80%) had postoperative transient persistent hiccups. Binary univariate logistic regression analysis showed that male, higher body mass index (BMI), smoker, Hoehn and Yahr stage (off), preoperative use of amantadine, hypnotic, Hamilton anxiety scale and Hamilton depression scale scores, and postoperative limited noninfectious peri-electrode edema in deep white matter were suspected risk factors for postoperative hiccups (p < 0.1). In binary multivariate logistic regression analysis, male (compared to female, OR 14.00; 95% CI, 1.74−112.43), postoperative limited noninfectious peri-electrode edema in deep white matter (OR, 7.63; 95% CI, 1.37−42.37), preoperative use of amantadine (OR, 3.64; 95% CI, 1.08−12.28), and higher BMI (OR, 3.50; 95% CI, 1.46−8.36) were independent risk factors for postoperative hiccups. Conclusions: This study is the first report about the risk factors of hiccups after STN DBS under general anesthesia for PD patients. The study suggests that male, higher BMI, preoperative use of amantadine, and postoperative limited noninfectious peri-electrode edema in deep white matter are independent risk factors for postoperative hiccups of STN-DBS for PD patients. Most hiccups after STN-DBS for PD patients were transient and self-limiting.

Protracted Hiccups Induced by Aripiprazole and Regressed after Administration of Gabapentin

Hiccups are sudden, repeated, and involuntary contractions of the diaphragm muscle (myoclonic contraction). It involves a reflex arc that, once activated, causes a strong contraction of the diaphragm immediately followed by the closure of the glottis translating into the classic "hic" sound. Hiccups can be short, persistent, and intractable depending on the duration. The most disabling hiccups often represent the epiphenomenon of a medical condition such as gastrointestinal and cardiovascular disorders; central nervous system (CNS) abnormalities; ear, nose, and throat (ENT) conditions or pneumological problems; metabolic/endocrine disorders; infections; and psychogenic disorders. Some drugs, such as aripiprazole, a second-generation antipsychotic, can induce the onset of variable hiccups. We describe herein the cases of three hospitalized patients who developed insistent hiccups after taking aripiprazole and who positively responded to low doses of gabapentin. It is probable that aripiprazole, prescribed at a low dosage (<7.5 mg/day), would act as a dopamine agonist by stimulating D₂ and D₃ receptors at the "hiccup center" level-located in the brain stem-thus triggering the hiccup. On the other hand, gabapentin led to a complete regression of the hiccup probably by reducing the nerve impulse transmission and modulating the diaphragmatic activity. The present case series suggests the use of low doses of gabapentin as an effective treatment for aripiprazole-induced hiccups. However, our knowledge of the neurotransmitter functioning of the hiccup reflex arc is still limited, and further research is needed to characterize the neurotransmitters involved in hiccups for potential novel therapeutic targets.

Dose-dependent L-dopa/carbidopa-induced hyponatremia presenting with hiccups

Levodopa (L-dopa) is the most effective antiparkinsonian agent and is well tolerated at all stages of the disease. However, both motor and nonmotor adverse events are reported with the use of L-dopa. Electrolyte imbalances such as hyponatremia and hiccups with L-dopa/carbidopa are very rare. For the first time, we are reporting a case of L-dopa/carbidopa-induced hyponatremia and hiccup cooccurring in a 75-year-old male. He symptomatically improved after reducing the dose of levodopa/carbidopa, indicating a dose-dependent nature of these adverse events. Clinicians who prescribe L-dopa/carbidopa should be mindful of the potential for precipitating SIADH and hiccups, especially in elderly patients.

Hiccups in Parkinson's disease: an analysis of cases reported in the European pharmacovigilance database and a review of the literature

BACKGROUND

Some reports have suggested an association between dopamine agonists and hiccups, involuntary contractions that merit full clinical attention because they can be very debilitating. Many drugs frequently used to treat hiccups are formally contraindicated in Parkinson's disease due to their liability to worsen motor symptoms, making the treatment of hiccups problematic in this disease. The objective of the present study was to analyze all spontaneous reports of hiccups from the European Pharmacovigilance Database in patients with Parkinson's disease and/or on dopaminergic drugs. Finally, we sought to identify evidence-based recommendations on the management of hiccups in Parkinson's disease.

METHODS

We searched for all reports of hiccups in the European Pharmacovigilance Database (EudraVigilance) and calculated proportional reporting ratios for dopamine agonists and hiccups. We reviewed the literature on Parkinson's disease, dopamine agonists, and hiccups, searching for specific treatment recommendations for hiccups in this disease.

RESULTS

Both rotigotine and pramipexole fulfilled the criteria to generate a safety signal. We found 32 and 13 cases of hiccups associated with dopamine agonists in EudraVigilance and the literature, respectively. There were no specific recommendations for the management of hiccups in Parkinson's disease in the clinical guidelines consulted.

CONCLUSIONS

We have found evidence that rotigotine and pramipexole are associated with the appearance of hiccups and that this adverse reaction occurs predominantly in males. Given the scarce information available, specific recommendations are needed in clinical guidelines for the adequate management of hiccups in Parkinson's disease.

Gender Differences in Hiccup Patients: Analysis of Published Case Reports and Case-Control Studies

CONTEXT

Although sporadic male predominance in hiccup patients has been reported, the association between gender differences and triggering factors has rarely been evaluated in patients with hiccups.

OBJECTIVES

The aim of this study was to investigate whether gender differences exist in hiccup patients by analyzing all previously published hiccup literature containing gender and etiology information.

METHODS

Published literature on this topic was identified using a standardized search strategy in the PubMed, SCOPUS, and CINAHL electronic databases. The literature search included studies published from January 1990 to December 2013. Searches were limited to English-language publications. Of 476 identified studies, 318 studies were eligible including eight case-control studies that contained nonhiccup control groups. Triggering factors for hiccups were categorized into two types: central nervous system (CNS) and non-CNS causes. Odds ratios (ORs) were calculated for the eight case-control studies and event rates for the other studies by meta-analysis. In addition, gender differences and mean ages were analyzed for the case studies.

RESULTS

Pooled OR was 2.42 (95% confidence interval [CI] 1.40-4.17) with inclination for male predominance. Subgroup analysis by cause showed clear male predominance in the non-CNS type with OR of 11.72 (95% CI 3.16-43.50), whereas indistinct in the CNS type with OR of 1.74 (95% CI 0.95-3.16). Of the remaining 310 studies with 864 patients, previous findings were consistent. Male predominance was consistent in non-CNS (85.1%, 95% CI 78.2-90.2) and unknown origin (82.2%, 95% CI 75.8-87.2) patients, whereas mitigating the sex discrepancy in those with CNS origin (65.8%, 95% CI 53.1-76.5).

CONCLUSION

We demonstrated male predominance in hiccup patients. This gender difference for hiccups was more pronounced in patients with non-CNS causes, whereas indistinct in patients with CNS causes.

Hiccup: mystery, nature and treatment

Hiccup is the sudden onset of erratic diaphragmatic and intercostal muscle contraction and immediately followed by laryngeal closure. The abrupt air rush into lungs elicits a "hic" sound. Hiccup is usually a self-limited disorder; however, when it is prolonged beyond 48 hours, it is considered persistent whereas episodes longer than 2 months are called intractable. A reflex arc involving peripheral phrenic, vagal and sympathetic pathways and central midbrain modulation is likely responsible for hiccup. Accordingly, any irritant in terms of physical/chemical factors, inflammation, neoplasia invading the arc leads to hiccups. The central causes of hiccup include stroke, space occupying lesions and injury etc, whereas peripheral causes include lesions along the arc such as tumors, myocardial ischemia, herpes infection, gastroesophageal reflux disease and applied instrumentations on human body etc. Besides, various drugs (eg, anti-parkinsonism drugs, anesthetic agents, steroids and chemotherapies etc) are the possible etiology. An effective treatment of persistent hiccup may be established upon the correct diagnosis of lesion responsible for the serious event. The pharmacotherapy of hiccup includes chlorpromazine, gabapentin, baclofen, serotonergic agonists, prokinetics and lidocaine. Non-pharmacological approaches such as nerve blockade, pacing, acupuncture and measures to hold breathing are also successful. Finally, alternative medicines and remedies are convenient to treat hiccups with uncertain effect. In conclusions, hiccup is likely to result from lesions involving the hiccup reflex arc. The lesion may need to be localized correctly for ablative treatment in patients with intractable hiccup. Apart from lesion ablation, drugs acting on reflex arc may be effective, while some other conventional measures may also be tried.