Huntington’s Disease and the NDIS: Access and Planning

Huntington’s disease and the NDIS: evidencing three conditions at once

At the end of December 2019, a Freedom of Information request established that 833 people with Huntington’s disease listed as a diagnosis held an NDIS package.

The best available estimate of the number of Australians living with Huntington’s is around 2,600.

Those two figures are not directly comparable — some people with HD are over 65 and outside the scheme, some are early in the disease and not yet seeking support, and the NDIS has grown since 2019. But the gap is wide enough to be worth taking seriously, because Huntington’s is in several respects an ideal fit for the NDIS: it is permanent, it is progressive, it typically begins between 30 and 50 so most people are well under the age limit at diagnosis, and it produces substantial functional impairment across multiple domains.

So the under-representation is not mainly about eligibility. It is about applications not being made, and about applications that are made being poorly evidenced — because Huntington’s is unusually difficult to document for the NDIS, for a reason this guide is largely about.

That reason: the part of HD that drives the most support need is the part an assessment is least likely to capture.

Huntington’s is on List B

The NDIS access lists work in two tiers. List A holds conditions the NDIA accepts as almost certainly meeting the whole disability test — permanence and substantially reduced functional capacity together. List B holds conditions accepted as likely to result in a permanent impairment, with functional impact still to be evidenced.

In the current operational guideline, Huntington’s disease appears on List B, under “Conditions primarily resulting in neurological impairment,” alongside Parkinson’s disease, Alzheimer’s dementia, vascular dementia, multi-infarct dementia, Creutzfeldt-Jakob disease and post-polio syndrome.

What that means in practice:

Permanence is not in dispute. The guideline states that for degenerative impairments, or those that get worse over time, the NDIA considers them permanent. In HD, with a genetically confirmed diagnosis, nobody is going to argue the point. It takes off the table a dispute that absorbs an enormous amount of effort elsewhere.

Functional capacity has to be evidenced, in at least one of six domains: mobility, communication, social interaction, learning, self-care and self-management. For Huntington’s, several of these will usually apply, and the ones that apply most strongly are the hardest to write up.

Age is usually not the problem. This distinguishes HD from most of the progressive neurological conditions covered elsewhere in this library. With a mean onset around 45, and about 25 per cent of people having onset after 50, the great majority of people with Huntington’s are comfortably under 65 when symptoms begin and can therefore join the scheme. The age issue in HD arrives later, as people age through the scheme, and as a boundary question for the minority with late onset.

The practical point for the minority who are near 65: NDIS access depends on age at application, not at diagnosis, and there is no exception. If HD is being investigated in somebody in their early sixties, the access request should go in now rather than after the diagnosis is confirmed.

Why the evidence is hard, and what to do about it

Here is the central problem. A person with Huntington’s disease attends an assessment. The assessor sees chorea — obvious, visible, easily documented. What the assessor does not see, in one hour, in a quiet room, with a family member answering the hard questions:

Executive dysfunction. The person cannot plan a week, sequence a task, start something without a prompt, or switch between activities. They can still answer questions in an interview. Nothing about an hour’s conversation reveals that they have not paid a bill in eight months.

Apathy. Not depression, not refusal — a loss of the mechanism that converts an intention into an action. This is among the strongest predictors of support need in HD and it is invisible in any setting where somebody else has organised the appointment.

Irritability and loss of impulse control. Which will not appear in a short, structured, polite interaction, and which may be the reason the person has lost their job, their relationship and their driver’s licence.

Lack of awareness of their own deficits. Common in HD, which means the person themselves will frequently under-report everything above, in good faith.

The combination effect. A person with chorea alone needs equipment. A person with chorea plus executive dysfunction plus apathy plus irritability needs a trained human being present for most of the day. Those are different plans and the difference is not visible in the movement disorder.

What fixes this. Four specific things, and they are worth insisting on.

A neuropsychological assessment. The single most valuable document in an HD access request, for the same reason it is in acquired brain injury: it converts invisible frontal-lobe impairment into measured, written findings. Ask for it by name, and ask for it to address executive function specifically rather than general cognition. Note that standard screens can mislead in HD — a person with HD may perform reasonably on a brief cognitive screen while being entirely unable to run their own life.

A functional report from somebody who has seen a real week. An occupational therapy functional assessment conducted at home, ideally over more than one visit, covering what actually happens rather than what the person can demonstrate on request.

A written account of a real week, by the family. Not a summary of difficulties — a diary. Monday: did not get out of bed until 2pm, did not eat until prompted, lost temper with the neighbour, could not find the car keys, left the stove on. This document is frequently the most persuasive thing in a file and families are rarely told to produce it.

A psychiatric or behavioural report where there are psychiatric symptoms, which there usually are. Depression affects around 40 per cent of people with HD at more than twice general population rates, and irritability, aggression, paranoid delusions and apathy are all frequent. These are support needs, not just clinical facts, and they should be documented as such.

What the clinical letter needs to say

Specialists write good clinical letters that make poor NDIS evidence, because the two documents have different jobs. Ask the HD service or neurologist to include:

The diagnosis, genetically confirmed, with the CAG repeat number and the date.

Each of the three domains separately — motor, cognitive, psychiatric — with current function described in tasks rather than scores.

Something in every applicable NDIS domain. Mobility, self-care, social interaction and self-management will usually all apply, and communication frequently does because dysarthria appears early. A domain the letter is silent on is a domain with no evidence behind it.

The trajectory, with dates. HD runs a median of 15 to 18 years, which means the progression within a plan period is real but gradual — a different drafting problem from MND. Something like: “At review two years ago he was working part-time and living independently. He now requires prompting for all personal care, cannot manage money, and cannot be left alone for a full day. On this trajectory, 24-hour support will be required within two to three years.”

An explicit statement that cognition and behaviour, rather than the movement disorder, drive the support requirement, where that is true. Planners default to reading HD as a movement disorder. Say otherwise in writing.

What happens without supports. Falls, weight loss, missed medication, social isolation, police contact, eviction, hospital admission, carer breakdown.

Getting a plan that fits

Ask for the plan to anticipate progression. Specify that the condition will deteriorate across the plan period and that funding should reflect anticipated rather than current need, with the trajectory sentence as justification.

Ask for flexible Core funding. Core supports are generally flexible between categories, so a plan with a generous Core allocation can absorb an increase in support hours without a formal variation. An itemised plan cannot.

Ask for support coordination, and insist. In a condition that needs neurology, psychiatry, neuropsychology, speech pathology, dietetics, occupational therapy, physiotherapy, behaviour support, a support provider and frequently a housing solution to all move together, over fifteen years, coordination is the plan rather than an addition to it. The 2020 gap analysis for Huntington’s Victoria recorded that the NDIS and aged care were both described as hard to navigate and often a poor fit for HD, particularly around risk and choice.

Ask for specialist behaviour support, and be specific about who delivers it. More on this below.

Ask for allied health as a category rather than a list of named practitioners, so the mix can change.

Ask for a case conference to be funded. Allied health time for multidisciplinary case conferencing is claimable and almost never requested, and in a three-domain condition it is where most of the value is.

Ask for therapy for the family, not only the person. Several of the strongest interventions in HD — behaviour strategies, communication approaches, environmental adjustments — are delivered through the people around the person.

And ask about staff continuity in the plan conversation. In HD this is clinical. Covered in supported independent living with Huntington’s.

Behaviour support in Huntington’s, done properly

This deserves its own section because it is where HD plans most often go wrong, in both directions.

Why it is needed. Irritability, explosiveness, aggression, disinhibition, perseveration and paranoid delusions are frequent in HD. Where paid support workers are involved and a behaviour of concern exists, a behaviour support plan is required, and if any regulated restrictive practice is in use — seclusion, chemical restraint, mechanical restraint, physical restraint or environmental restraint — the full regulatory framework applies: a plan written by an NDIS behaviour support practitioner, state authorisation, monthly reporting to the NDIS Quality and Safeguards Commission and a documented strategy to reduce and eliminate the practice. A locked kitchen or a locked front door is environmental restraint. Medication given to manage behaviour rather than to treat a diagnosed condition is chemical restraint — and in HD, where antipsychotics are legitimately prescribed for chorea and sometimes used to manage irritability, that distinction needs to be documented carefully by the prescriber rather than assumed. The general framework is in behaviour support and restrictive practices.

Why generic behaviour support frequently fails in HD. Most positive behaviour support training is built around learning: identify the function of the behaviour, teach a replacement, reinforce it. That model assumes the person can learn and generalise a new strategy. In Huntington’s, with executive dysfunction, impaired cognitive flexibility, perseveration and limited insight, the learning route is substantially closed. A plan built on teaching the person to use a different strategy when frustrated will not work, and when it does not work the person gets described as non-compliant.

What works instead is almost entirely environmental and relational: reducing demands, removing the triggers rather than teaching tolerance of them, absolute predictability of routine, giving warning before any change, not arguing with a fixed position, allowing far more time, and — more than anything — the same small group of workers who know the person’s early warning signs.

So the question to ask a behaviour support practitioner before engaging them is simply: how many people with Huntington’s disease have you written plans for? If the answer is none, the plan will probably be a generic one, and generic plans in HD generate restrictive practices rather than reducing them. Huntington’s Australia on 1800 244 735 can help identify practitioners with HD experience, and the state HD services can too.

If access is refused, or the plan is inadequate

Read the decision letter. It will name the limb of the test that was not met, which tells you what evidence to add.

Internal review under section 100 of the NDIS Act, within three months, with the NDIA having 90 days to decide. Add what was missing — usually the neuropsychological assessment and a functional report — rather than resending the same file.

Get an advocate. The NDIS Appeals programme funds free independent advocates for reviews and tribunal matters. They do this constantly and they cost nothing. Engage one at the start of a review, not after it fails.

Then the tribunal. The Administrative Review Tribunal took over from the Administrative Appeals Tribunal in October 2024. Applications are due within 28 days of the internal review decision, there is no fee for NDIS matters, and NDIS Appeals advocates can continue to assist.

For an inadequate plan rather than a refusal, request a plan reassessment on changed circumstances with fresh evidence, rather than waiting for the annual review. The 2020 gap analysis recorded that for the October to December 2019 quarter, the average time from access being met to an approved plan for HD participants was 79 calendar days, and that 53 plans were approved in that quarter. Plan processes take time, so start them before they are urgent.

Where health ends and the NDIS begins

Generally health-funded: diagnosis and genetic testing, neurology, psychiatry, medication including tetrabenazine on the PBS, hospital care, acute mental health care, and palliative care late in the disease. Genetic counselling for the person and their relatives is free through state genetic services. Specialist HD clinic attendance is health-funded, which means the age limit does not apply to it.

Generally NDIS-funded: personal care, overnight and 24-hour support, community participation, assistive technology and equipment, home modifications, support coordination, specialist behaviour support, and disability-related allied health including OT, physiotherapy and speech pathology for communication.

Contested in practice: dietetics, and speech pathology for swallowing. This matters in Huntington’s because nutrition is not a peripheral issue — weight loss is substantial, begins early and is clinically significant. See eating, weight and swallowing. Ask the HD service which route works in your state and, if one system refuses, ask the other.

Psychology and psychiatric care can fall either side depending on whether it is treating a mental illness or supporting disability-related function. Both arguments are available and the framing matters.