Abstract
Background Whilst stridor related to bilateral vocal cord paralysis (BVCP) is a recognised complication of increased intracranial pressure, it typically resolves with ventricular-peritoneal (VP) shunting. We present a case where tracheostomy was needed after successful VP shunting.
Case A 33-year-old-man presented with headache, slurred speech and immobility. His background included resected medulloblastoma with head-neck radiotherapy (aged 8), long-term VP shunt, and post-treatment ataxia which had progressed over 2 years with development of intermittent nocturnal stridor. He underwent emergent shunt revision for a distally blocked shunt, with resolution of hydrocephalus. Two days afterwards, he developed hiccups and worsened stridor which progressed to respiratory obstruction over 24 hours. Laryngoscopy showed tightly adducted midline vocal folds with coarse pharyngeal, palatal, and tongue myorhythmia (3 Hz). There was no response to benzodiazepines and no epileptiform activity on EEG. He had loss of gag reflex on neurological examination with normal eye movements. A cerebral and neck MRI showed resolution of hydrocephalus and post-treatment changes related to previous medulloblastoma. There has unfortunately been no improvement in vocal fold movement over 3 weeks.
Discussion Subacute stridor may be due to pathological upper motor neurone activation of the branchial motor component of the vagal nerves with this person’s background brain injury.1 Tight acute midline cord positioning and myoclonus may be unusually caused by bilateral recurrent laryngeal nerve lesions secondary to changes in intracranial pressure,2 3 but is not the favoured sole mechanism here. Botulinum toxin therapy could provide benefit but may compromise a future safe swallow.
References
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Mayhew JF, Miner ME, Denneny J. Upper airway obstruction following cyst-to-peritoneal shunt in a child with a Dandy-Walker cyst. Anesthesiology. 1985;62(2):183–4.
