Case report

Intractable hiccups resolved after resection of a cavernous malformation of the medulla oblongata

Hiccups are a well-known short-term phenomenon in daily life. If they persist or become intractable, they may be a primary symptom of a disease. Recent studies identified the medulla oblongata as the neuroanatomic center of the hiccup reflex arc. In previous cases, an isolated lesion at the dorsal side of the medulla oblongata induced intractable hiccups.

We herein describe a patient with a perimedullary arteriovenous fistula (PMAVF) at the craniocervical junction who had intractable hiccups. A 70-year-old male presented with a 3-year history of intractable hiccups that continued for a few days every week. An initial examination failed to identify the underlying cause, and neither medicine nor self-treatment attenuated his symptoms. Intracranial T2-weighted magnetic resonance imaging showed a hyperintensity area within the dorsolateral medulla and flow voids along the dorsal side of the cervical spine. Angiography revealed PMAVF fed by the left C1 radiculomedullary artery. Obliteration of the fistula was performed, after which intractable hiccups had completely disappeared within 1 week.

This is the first case report of PMAVF at the craniocervical junction presenting with intractable hiccups that suggested a lesion in the dorsal side of the medulla. The mechanisms underlying hiccups are also discussed.

The aim of this study was to evaluate the clinical features, surgical complications, and functional outcomes of the surgical treatment of patients with cavernous malformations (CMs) involving the medulla oblongata.

The charts of 69 patients undergoing surgical treatment of CMs in the medulla oblongata, pontomedullary, and cervicomedullary junctions between 2011 and 2017 were retrospectively reviewed. Patient demographics, lesion characteristics, operative documents, and patient outcomes were examined.

Of the 69 patients, the male-to-female ratio was 1.3. The mean patient age was 32.6 years, and the mean mRS score was 2.7 on admission. Postoperatively, 21 patients (30.4%) had deficits of cough reflexes, and 6 patients (8.7%) experienced respiratory rhythm disorder and dyspnea. The mean follow-up duration was 35.3 months. At the last follow-up evaluation, the mean mRS score was 1.8, and 53 patients (80.3%) had favorable outcomes, with mRS scores ≤2. The conditions of the patients improved in 45 cases (68.2%), remained unchanged in 11 cases (16.7%), and worsened in 10 cases (15.1%) relative to their preoperative baseline. The independent adverse factors for long-term functional outcome were increased age, multiple hemorrhages, presence of developmental venous anomalies, and lack of perilesional edema.

Respiratory dysfunction and deficits of cough reflexes can commonly occur during the early postoperative period for surgical resection of CMs involving the medulla oblongata. Favorable functional outcomes can be achieved by surgery, especially for younger patients who experience fewer hemorrhages and have lesions with perilesional edema and the absence of developmental venous anomalies.

Hiccups are defined as sudden-onset involuntary contractions of the diaphragm followed by immediate inspiration and laryngeal closure, and they are considered intractable if prolonged beyond 1 month. A reflux arc involving phrenic, vagal, and central midbrain modulation is likely responsible for hiccups. We herein report a case of intractable hiccups caused by compression of the dorsal aspect of the medulla oblongata after treatment of a partially thrombosed distal posterior inferior cerebellar artery (PICA) aneurysm.

A 51-year-old man presented with severe headache and was diagnosed with subarachnoid hemorrhage. Magnetic resonance imaging and cerebral angiography showed a partially thrombosed distal PICA aneurysm associated with a fusiform aneurysm in the ipsilateral vertebral artery. Based on the limited distribution of the clot, we performed endovascular coil occlusion of the aneurysm lumen followed by parent vessel occlusion for the distal PICA aneurysm. After the procedure, the patient presented with hiccups that could not be controlled by any medications. Magnetic resonance imaging showed an area of hyperintensity at the bilateral dorsal part of the medulla adjacent to the embolized aneurysm. The hiccups spontaneously disappeared 1 month after the procedure, and the abnormal signal findings also disappeared within the same period. The hiccups did not recur for 30 months postoperatively.

In this case, the precise location of the culprit lesion causing the patient's hiccups was the dorsal medulla oblongata. Clinicians should be aware of the possibility of structural or functional disorders of the reflux arc in patients with intractable hiccups.