Neurology

TO THE EDITOR: The article by Stevens and Schweitzer1 contains many useful teaching pearls for frontline physicians and generalists. I concur with the final diagnosis reached and the excellent teaching points emphasised in the article. I would like to make two important points regarding localisation. First, binocular diplopia can be caused by diseases in a variety of locations in the neurological axis, not just the extraocular muscle. Other possible locations include the brainstem, the cranial nerves (III, IV and/or VI), the neuromuscular junction and the orbit itself. Accompanying features will help distinguish the location; for example, the presence of hemiparesis, cerebellar signs, or lower cranial nerve abnormalities would localise to the brainstem. Second, localisation is critical before organising neuroimaging, as knowing where the lesion is will prove useful for the radiologist. The likelihood of subtle pathologies being detected by the radiologist increases significantly when the site of potential localisation is included in the clinical request information. This helps to reduce the possibility of false negatives or misinterpretation if clinical correlation is not applied to test requests.2 Finally, there are two differential diagnoses to consider in this case. Myasthenia gravis, an uncommon disorder of the neuromuscular junction, is known to be a great mimicker and can cause various patterns of ophthalmoparesis and diplopia3 and it should be considered in all cases of binocular diplopia. In the article by Stevens and Schweitzer,1 this diagnosis was less likely in the patient given the painful nature of the ophthalmoparesis. The other rare differential diagnosis with serious implications to consider is a dural (or indirect) carotid‐cavernous fistula. Patients with this condition can present with painful diplopia without significant visual loss; they are frequently misdiagnosed by specialists and are eminently treatable endovascularly.4 The absence of orbital signs (eg, proptosis) and ocular signs (eg, arterialised “corkscrew” conjunctival vessels) assisted in excluding this condition as a differential in this case.

Benjamin Nham

The known: Recent advances in digital infrastructure in Australia allow linkage of administrative and clinical datasets.

Monique F Kilkenny · Joosup Kim · Nadine E Andrew · Vijaya Sundararajan · Amanda G Thrift · Judith M Katzenellenbogen · Felicity Flack · Melina Gattellari · James H Boyd · Phil Anderson · Natasha Lannin · Mark Sipthorp · Ying Chen · Trisha Johnston · Craig S Anderson · Sandy Middleton · Geoffrey A Donnan · Dominique A Cadilhac

To the Editor: Behavioural and psychological symptoms of dementia can manifest as aggression directed towards staff or other residents,1 often culminating in recourse to the local emergency department as a “permanent solution”. What does the law say? Under Division 2, User Rights Principles 2014 (section 96-1, Aged Care Act 1997), the only circumstances in which a provider may ask a care recipient to leave a residential care service are if (i) the service is closing; or (ii) the service no longer provides suitable accommodation and care (as assessed by an aged care assessment team or at least two medical or other health practitioners chosen by the recipient who are competent to assess their care needs) and the provider has not agreed to provide the care that the recipient presently needs; or (iii) the recipient no longer needs the care provided, as assessed by an aged care assessment team; or (iv) the recipient has not paid any agreed fees for a reason within their control; or (v) or the recipient has intentionally caused serious damage to the service or serious injury to staff or another care recipient; or (vi) the recipient is away continuously for 7 days or more from the service for reasons not permitted by the Aged Care Act or an emergency. The approved provider must neither imply nor take action to make the care recipient leave, unless suitable alternative accommodation is available that is affordable and meets the care recipient’s needs. Written notice must be given of the decision and reasons for it. A person cannot be asked precipitously to leave a nursing home or, in practical terms, hospital staff or family cannot be told that a bed is no longer available without adhering to the guidelines above. Intention regarding injury and behavioural and psychological symptoms of dementia is complex and cannot be used as grounds for discharge without proper assessment. An alternative is to use the Dementia Behaviour Management Advisory Service and Severe Behaviour Response Teams (24-hour helpline: 1800 699 799), which provide clinical support for carers of people with behavioural and psychological symptoms of dementia. Aged care consumers need to be aware of their rights around security of tenure, and facilities should be resourced sufficiently to fulfil their commitments under the Aged Care Act to care for residents with behavioural and psychological symptoms of dementia.

Carmelle Peisah · Tiffany Jessop · Henry Brodaty

To the Editor:I read with interest the article by Brukner and colleagues1 on traumatic cricket-related fatalities in Australia, which describes two autopsy-confirmed deaths due to subarachnoid haemorrhage following vertebral artery dissection, with a further 11 deaths suspected to be secondary to this condition. Two recent articles described a total of 230 cases of carotid or vertebral artery dissection temporally related to 45 different sports or recreational activities.2,3 The majority of episodes of arterial dissection were related to non-contact sports, including jogging, walking, swimming, golf, basketball, tennis and scuba diving. The mean age of patients was 35 years. The mechanism of non-traumatic dissection is thought to relate to shearing stress on the arterial wall with sudden neck rotation. Thus arterial dissection in golfers affected the right side in 11 of 14 patients (79%), and involved the posterior circulation in 12 of 14 patients (86%).4 Controversy regarding the association between neck manipulation and arterial dissection persists, although a retrospective case–control study found an odds ratio of 12.8 for prior neck manual therapy in individuals aged 55 years or less presenting with craniocervical arterial dissection.5 Arterial dissection may also occur spontaneously, the risk being increased in the setting of systemic lupus erythematosus, other connective tissue disorders, migraine and in the postpartum period. It is important that health professionals recognise that arterial dissection may occur spontaneously or as a result of non-contact sports and activities, and that persons of any age presenting with symptoms suggestive of anterior or posterior circulation ischaemia require urgent review and neuroimaging.

Adam Morton