Respiratory Arrest: A Complication of Arnold-Chiari Malformation in Adults

Abstract

We describe the cases of 2 adult patients who developed respiratory arrest and were found to have Arnold-Chiari malformation on magnetic resonance imaging. Following posterior fossa decompression both patients improved, though one of them subsequently died during sleep. Imaging of the craniocervical junction should be part of the workup of patients with unexplained apneic episodes.

Acute respiratory arrest following partial suboccipital cranioplasty for cerebellar ptosis from Chiari malformation decompression

“…Additionally, acute respiratory arrest has been reported previously at 2, 3, and 42 hours, and as late as 2 months after suboccipital craniectomy for CM-I. 5,9,14,27 Sudden respiratory deterioration due to the initial procedure has been described, possibly as a result of the loss of respiratory center neurons in the morbid condition, with this loss possibly due to congenital deformity or lengthy compression. 15,23 Although there was no obvious tether identified intraoperatively on the spinal cord or brainstem in either case, one wonders if stretching on the vulnerable cervicomedullary junction from the elevation of the cerebellum during the cerebellar shelving procedure is possibly responsible.…”

Central sleep apnoea in Arnold-Chiari malformation: evidence of pathophysiological heterogeneity

“…Type II ACM is a more extensive malformation, which also includes downward displacement of the medulla [4].…”

“…The most common findings include motor deficiency, sensory loss, lower cranial palsy, and cerebellar syndrome [5,6]. Respiratory insufficiency seems to be particularly uncommon [6], and is frequently unmasked in situations characterized by increased ventilatory demand [4]. It is of note, that central and obstructive apnoeas often associate with ACM [1,4].…”

“…Respiratory insufficiency seems to be particularly uncommon [6], and is frequently unmasked in situations characterized by increased ventilatory demand [4]. It is of note, that central and obstructive apnoeas often associate with ACM [1,4].…”

“…The first patient has the "hypercapnic type" of CSA, with impairment or loss of the automatic control of ventilation. Causative mechanisms may include: 1) lack of functional chemoreceptor afferents, owing to carotid body denervation via injury to the 9th cranial nerve pair; 2) insensitivity of peripheral chemoreceptors, owing to lo-wer brain stem involvement [14]; 3) compression of the phrenic motoneurons in the anterior horn of the medulla by the associated syringomyelia, or compromised vascular supply to the brain stem [4]; and 4) direct bulbar compression of the respiratory centre by an odontoid apophysis or by downward displacement of the cerebellar tonsils [15].…”