Zechariah, the father of John the Baptist was unable to speak' after meeting an angel in the temple, but his tongue was loosed' shortly after John's birth. The apparently isolated voice loss was of rapid onset, complete and and similarly resolved suddenly and fully after a period of nine months on the day of John's circumcision.

The description implies loss of voice rather than disordered articulation ruling out dysarthria and dysphonia. Even aphonic patients, such as those with bilateral vocal cord paresis, can still whisper. The absence of any accompanying neurological deficit coupled with Zechariah's apparent retention of understanding and the ability to communicate by gesture effectively exclude a receptive or global aphasia. This is a motor aphasia.

A neoplastic cause (primary or secondary) is possible but would more likely have produce a gradual but worsening deficit. Infective processes (abscess, encephalitis) should be considered but are effectively ruled out by the speed of onset and absence of other constitutional symptoms. Hysteria is unusual in this age-group. The history points to a vascular aetiology but the absence of headache or impairment of consciousness make intracerebral haemorrhage or subdural haematoma unlikely diagnoses.

Given Zechariah's advanced age (vv7,18), the localised nature of the lesion and the duration of the deficit, Luke favours brain infarction from embolic occlusion of a branch of the middle cerebral artery. The sudden recovery is clearly miraculous.

At a spiritual level Zechariah's condition was the direct result of his disbelief in Gabriel's prophecy that his wife would have a son (v18) and was a sign confirming the truth of Christ's messiahship. The whole episode is a fitting reminder that nothing is impossible with God.