Sudden unexpected nocturnal death in Chiari type 1 malformation and potential role of opioid analgesics

Abstract

Background:Chiari malformation type 1 (CM1) is a common congenital anomaly of the craniocervical junction. CM1 is reported to run a usually benign course and patients typically experience no symptoms or chronic, slowly progressive symptoms. However, recent reports indicate that a subset of patients with CM1 may present with acute deterioration and sudden unexpected death (SUD). We report a case of SUD during sleep in a young man with CM1, which we believe was related to the administration of common and therapeutic doses of narcotic analgesics for the management of pain. We will clarify the pathophysiology of acute deterioration and SUD in CM1 and the possibility that the adverse effects of opiate analgesics likely were the leading cause of death in our patient.Case Description:In this review, we present a 29-year-old male with worsening headache secondary to previously diagnosed CM1. The patient died suddenly and unexpectedly after administration of common and therapeutic doses of narcotic analgesics for the management of pain.Conclusion:The mechanism(s) of acute neurological deterioration and sudden death in patients with CM1 remains poorly understood. We believe the rapid fatal deterioration in our patient following administration of opioids suggests that this category of medication may cause sudden unexpected “neurogenic” cardiac death in CM1 patients by inducing sleep-related breathing difficulties and associated hypercapnia. Hypercapnia by further increasing intracranial pressure can result in a sudden pressure-induced decompensation of the cardiopulmonary control centers in the brain stem and cause instantaneous cardiorespiratory arrest.

Unexpected Progression of Tonsillar Herniation in Two Pediatric Cases with Chiari Malformation Type I and Review of the Literature

“…Because of the rarity of these types of cases, the pathophysiology and outcomes are not known in an increased tonsillar herniation yet. Moreover, a few cases with sudden unexpected death were previously reported in CM-1, of which the pathophysiology was still poorly understood [27]. Due to the suspense on etiology of sudden death in CM-1, any progression in the degree of tonsillar prolapsus should be taken care of immediately for preventing acute deterioration, and even sudden death.…”

Sudden unexpected nocturnal death in Chiari type 1 malformation and potential role of opioid analgesics

“…Our recent article entitled “Sudden unexpected nocturnal death in Chiari type 1 malformation and potential role of opioid analgesics”[ 5 ] was criticized by Jonathan and Shlomi. [ 3 ] They challenged our opinion without any reference to authenticate their assertions.…”

“…The term “trapped fourth ventricle” is used to describe a dilated fourth ventricle due to obstruction of both its inlet and outlet. [ 1 5 ] Shortly before his death, the patient had undergone brain imaging examinations at two different institutions. These studies as well as a postmortem examination excluded the possibility of a trapped fourth ventricle based on the apparent patency of the Sylvius aqueduct.…”

“…These studies as well as a postmortem examination excluded the possibility of a trapped fourth ventricle based on the apparent patency of the Sylvius aqueduct. [ 5 ] Cystic dilatation of the fourth ventricle is a well-known feature of DLCFV. [ 1 5 ] Different mechanisms have been postulated to explain the fourth ventricle dilation and distribution of periventricular edema observed in DLCFV.…”

“…[ 5 ] Cystic dilatation of the fourth ventricle is a well-known feature of DLCFV. [ 1 5 ] Different mechanisms have been postulated to explain the fourth ventricle dilation and distribution of periventricular edema observed in DLCFV. [ 1 5 ] Our experience and published literature indicate that the most likely etiology of DLCFV is increased fragility of the surrounding fourth ventricle tissues to elevated intraventricular pressure, or unequal distribution of intraventricular pressure in tension hydrocephalus such that the intraventricular hypertension primarily affects the ventricle closest to the point where the flow of the cerebrospinal fluid (CSF) is obstructed.…”