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Deafness is rare in ischaemic stroke but sometimes occurs as a result of lower pons infarction. The main cause of such deafness is occlusion of the anterior inferior cerebellar artery (AICA); occlusion of the superior cerebellar artery (SCA), which perfuses the higher pons, causes SCA syndrome and also results in deafness but is extremely rare.1 In the present report, we describe a patient with SCA syndrome, whose initial complaint was contralateral hearing loss.
A 64 year old male with untreated hyperglycaemia and hypertension was admitted 4 h after the sudden onset of deafness in his right ear. Hearing loss was the only complaint and other neurological signs were absent. Right sensorineural hearing loss was revealed by a hearing test (fig 1A). After several examinations including stapedial reflexes and speech discrimination, an initial diagnosis of sudden deafness was made. However, 8 h later the patient complained of diplopia, vertigo, and nausea. Impaired abducens function in the right eye and bilateral lateral gaze nystagmus were observed. Finger-nose and heel-knee tests suggested left cerebellar ataxia. Hence, a diagnosis of SCA syndrome was made, and argatroban, an anti-coagulant, was administered. Diffusion weighted magnetic resonance imaging (MRI) 12 h after onset showed infarctions in the left cerebellum (fig 1B) and lateral superior pons (fig 1C). Magnetic resonance angiography showed loss of blood flow in the lower basilar artery (fig 1D). Respiratory failure developed 4 h later, and the next day the patient also showed right hemiparesis and Horner’s syndrome. Bilateral cortical blindness was also present. A diagnosis of SCA syndrome with hemiparesis and cortical blindness was made. A fluid attenuated inversion recovery (FLAIR) image 2 weeks later showed an enlarged infarction in the left cerebellum, and a new infarction in the right cerebellum, dorsal pons, and bilateral occipital lobes (fig 1E). The patient’s symptoms remained unchanged 3 months later.
SCA syndrome shows ipsilateral cerebellar ataxia and Horner’s syndrome, contralateral superficial sensory disturbance and hearing loss, as well as nystagmus toward the impaired side, vertigo, and nausea.2 Fibres from the contralateral auditory nucleus join the lateral lemniscus, pass into the brain, and terminate in the hearing centre. Therefore, impairment of the lateral lemniscus on one side causes hearing loss on the other. In SCA infarction, the ischaemic lesion occurs in the area where fibres from the nucleus have already crossed, and therefore sensory hearing loss is observed in the contralateral side.
We describe a rare case of SCA syndrome which began with deafness in one ear. Although deafness sometimes occurs as a result of brainstem infarction, most cases of ipsilateral hearing loss are due to AICA infarction.3 To our knowledge, the study by Doyle et al is the only previous report of hearing loss due to contralateral SCA infarction.1 Amarenco et al described a large series of SCA syndrome cases, where no patient showed contralateral deafness.4 The present report presents a important finding regarding symptoms of ischaemic stroke, and suggests that hearing loss, although rare, can be the first symptom. It is necessary to carefully observe patients with sudden deafness.
Competing interests: none declared
The patient described in this letter consented to his details being published
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