///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47+00:00

Anesthetic Management of a Parturient with Hyperekplexia

Abstract Number: F-07
Abstract Type: Case Report/Case Series

Anthony Chau M.D.1 ; Marni Roitfarb M.D., M.P.H.2; Jean Marie Carabuena M.D.3; William Camann M.D.4

Introduction: Hyperekplexia (HK) is a hereditary disorder caused by a mutation encoding the postsynaptic inhibitory glycine receptors (GLRA1, GLRB) and presynaptic glycine transporter (SLC6A5) resulting in abnormal glycinergic neurotransmission.(1) Patients with HK experience exaggerated startle reflex in response to unexpected acoustic, tactile or other stimuli such as emotional stress. (2) Neonates may present with hypertonia, developmental delays, apnea and sudden death.(3) Clonazepam, an allosteric potentiator of GABA(A) receptor, is the mainstay of treatment.(1)

Case: A 38 yo G6P1 presented for antenatal anesthesia consultation regarding her diagnosis of HK with symptoms including excessive generalized startle, hypertonia, and hyperreflexia to stimuli since birth. The patient was diagnosed after a workup of autonomic instability, postural hypotension, syncope and sinus tachycardia. The maternal grandmother and mother have history consistent with HK. Her first pregnancy was an uncomplicated vaginal delivery with epidural analgesia. The first baby boy developed feeding discoordination, increased startling and hypertonia at 2 weeks of age. Her current pregnancy was accompanied by worsening autonomic dysfunction and orthostatic presyncope. Her HK is well controlled on clonazepam and paroxetine. The patient returned at term with spontaneous labor and epidural analgesia was inserted uneventfully. In addition to establishing a rapport with the patient and her husband, every step during the epidural placement including skin sterilization, local anesthetic infiltration, and epidural needle insertion were preempted by meticulous verbal forewarning. Four hours later, patient delivered a baby girl (APGAR 9 and 9) with neonatology on standby. The baby was observed in NICU for 24 hours without problems and both patient and her baby were discharged on postpartum day 2.

Discussion: The inheritance pattern for HK can be autosomal dominant or recessive.(3) Our patient has a strong family and clinical history consistent with the autosomal dominant form of HK, and thus early consultation by anesthesiology and neonatology were crucial. Early epidural was recommended to minimize painful contraction stimuli and allow a more gentle, methodical approach to epidural placement, including copious preemptive warnings. Despite her autonomic dysfunction, the patient’s hemodynamics remained stable throughout the labor. Babies born to mothers with HK should be monitored for signs of respiratory distress, chest wall rigidity and apnea. Equipment for Intubation, mechanical ventilation and rescue intravenous midazolam were prepared in advance in anticipation for acute crisis.

References:

1. Thomas RH, et al. Brain. 2013;136(10):3085–95

2. Harvey RJ, et al. Trends in Genetics. 2008;24(9):439–47

3. Mineyko A, et al. Can J Neurol Sci. 2011;38(3):411–6

SOAP 2014