Managing behavioural symptoms in Sanfilippo syndrome

10 Jul 2023

Managing behavioural symptoms in Sanfilippo syndrome

In Sanfilippo, the build-up of waste products causes cells to malfunction and can lead to cell death. In the brain, this contributes to the progressive loss of abilities and skills, speech, and mobility.

However, these changes are also accompanied by often severe behavioural symptoms that can be very hard for families to manage. These symptoms include attention difficulties, lack of fear (of danger), hyperactivity, impulsivity, anxiety, and sleeping problems. 

Research into the behavioural symptoms of Sanfilippo syndrome has been limited, however, the research that has been done over recent years, together with extensive clinical experience, has led to the publication of recommendations and guidelines to help support families and their healthcare teams to manage these challenging symptoms.

In 2017, a team of clinical experts published a mini-review article, following a 2016 international meeting to discuss the behavioural symptoms seen in neurological forms of mucopolysaccharidoses (MPS). These include MPS I (Hurler syndrome), MPS II (Hunter syndrome), and MPS III (Sanfilippo syndrome). This work discussed the common behavioural symptoms in these conditions and the best approaches to ‘trouble-shooting’ and managing these symptoms.

Most recently, a project driven by Sanfilippo Children's Foundation and Cure Sanfilippo Foundation, USA, led to the publication of the Sanfilippo Syndrome: Consensus Guidelines for Clinical Care. These Guidelines provide a best-practice approach to managing all of the healthcare needs of individuals with Sanfilippo syndrome, including the behavioural symptoms.

Investigating pain and other contributing factors

In both publications, the first recommended step is to investigate any potential pain or physical factors that might be contributing to behavioural symptoms in patients. Musculoskeletal or gastrointestinal issues, for example, may lead to agitation and mood swings. Enlarged tonsils and/or adenoids may lead to airway obstruction and sleep problems, and hearing loss may exacerbate behavioural symptoms. The authors note that identification of these individual factors, via audiology, imaging, sleep tests and other clinical evaluations, can help to manage their impacts on behaviour.

Practical interventions to increase safety

Once physical factors are taken into account, practical interventions and changes to the individual’s environment should also be considered, for example, modifications to the home to increase safety, such as removing breakable objects and using safety gates and soft furnishings. Structured schedules and routines can also positively impact symptoms.

Behavioural interventions

Behavioural interventions can be used, but are best supported by healthcare professionals who are able to establish a rapport with the child, are familiar with the behavioural characteristics of Sanfilippo, and consider the specific behaviours together with the cognitive skill levels of the individual. Applied Behavioural Analysis therapy has been found to be beneficial in some individuals with Sanfilippo and can help enhance communication skills, maintain motor abilities and reduce unsafe behaviours. However, as the disease progresses and cognitive decline worsens, different approaches may be needed. 

Medications on a case-by-case basis

Medications can also be considered, however, there is little published evidence for their use and long-term effectiveness. Some medications can also have unpredictable side effects in children with Sanfilippo. The Guidelines suggest that the use of stimulant medications, mood stabilisers, antipsychotics and anti-anxiety drugs should be considered on a case-by-case basis and with short-term trials, followed by a review to identify the potential risks and benefits for each individual. The effects that Sanfilippo syndrome can have on the heart, liver and kidneys should also be taken into account when considering the potential side effects and risks of a medication. 

Improving sleep

Sleep alterations are one of the most consistent features of Sanfilippo syndrome, affecting up to 90% of individuals. Holistic strategies that include sleep hygiene, behavioural strategies and safety are recommended, but importantly, a full medical examination should investigate potential physical causes of sleep disturbance. These could include pain, seizures, oesophageal reflux, dental disease, or obstructive respiratory causes such as enlarged adenoids or tonsils, which are common in Sanfilippo. 

Research has shown that circadian rhythms are disrupted in children with Sanfilippo and as such, some studies have shown that melatonin can be an effective pharmacological approach to help manage sleep. Finding the right dose should be done in conjunction with an experienced healthcare professional.

Accessing support

Access to support services, social support, and other services like professional respite care is also essential for families, and these avenues can assist in managing disease symptoms and coping with their impacts. 

In Australia, Dementia Support Australia provides a free Childhood Dementia Support service with trained consultants who understand the behavioural symptoms of childhood dementias like Sanfilippo syndrome. They can visit with the family and help to identify some of the causes and triggers and strategies to help manage the behavioural symptoms. You can find out more about this service here, or call their 24-hour helpline on 1800 699 799. 

Other supporting organisations can also be found on our webpage here.

You can find more information about the global consensus clinical care guidelines for Sanfilippo Syndrome and download a copy here.