Cranial nerve palsy following central neuraxial block in obstetrics - a review of the literature and analysis of 43 case reports

Background: Cranial nerve palsy is a rarely reported complication of central neuraxial block in obstetrics. The aetiology is diverse and includes both decreased and increased intracranial pressure.

Methods: Medline, CINAHL, and EMBASE databases were searched to identify cases of cranial nerve palsy following obstetric central neuraxial block. Possible aetiology, clinical symptoms and signs, treatment, and time to resolution were assessed.

Results: Forty-one articles containing 43 case reports of cranial nerve palsy following obstetric central neuraxial block were identified. Four cranial nerve palsies were bilateral; the remainder being unilateral. The cranial nerves most commonly affected were the abducens (17 case reports) and facial (12 case reports) nerves. Epidural block was implicated in 25 cases. Classical post-dural puncture headache preceded cranial nerve palsy in 27 cases. Subdural haematomas were reported in six cases and cortical venous or transverse sinus thrombosis in one case. Epidural blood patch was administered for treatment of cranial nerve palsy in 17 cases. Thirty-five patients had complete resolution of symptoms but in eight the cranial nerve palsy was permanent. No case reports of olfactory, oculomotor, glossopharyngeal, accessory or hypoglossal nerve palsy were identified.

Conclusion: Intracranial hypotension is the most common aetiology of cranial nerve palsy after central neuraxial block in obstetrics. Neuroimaging is recommended in every case, to exclude other neurological causes. Epidural blood patch was the most utilised treatment for post-dural puncture cranial nerve palsy, but outcomes were variable. The majority of cranial nerve palsies resolved over the subsequent weeks and months.