Cognition and Neglect After Stroke: The Deficits That Don’t Show

Cognition and neglect after stroke: the deficits that don’t show

A woman is discharged home after a right hemisphere stroke. She walks with a stick. Her speech is normal. She passed every physical test the rehabilitation ward set her.

At home she eats only the right half of what is on her plate. She bumps the left side of her body against door frames. She shaves the right side of her face and leaves the left. When her daughter points this out she is baffled, then irritated, then insists there is nothing wrong.

Nothing about her is confused in the ordinary sense. She knows the date, her address, her grandchildren’s names. What has happened is that one half of the world has stopped existing for her, and — the part that makes it so difficult — she cannot perceive that anything is missing, because the apparatus that would notice is the apparatus that is damaged.

This guide covers the cognitive consequences of stroke: the ones that are easy to miss, the one that is genuinely strange, and the one that causes the most conflict in families.

Hemispatial neglect

Neglect is a failure to attend to, or act upon, one side of space — most commonly the left side, following a right hemisphere stroke. It is not blindness. The eyes work and the visual pathways may be intact. The brain simply does not allocate attention to that side.

What it looks like in practice:

• Eating only food on one half of the plate
• Reading only the right half of a page or a sentence
• Writing that drifts into the right margin
• Shaving, making up or dressing only one side
• Colliding with obstacles on the neglected side
• Not responding to people approaching from that side
• In drawing tasks, copying only half of an object

Neglect can also apply to the person’s own body (personal neglect), to near space, or to far space, and some people neglect one side of imagined or remembered scenes too.

Its significance is practical: neglect is one of the strongest predictors of poor functional outcome after stroke, worse in many respects than the motor deficit, because a person who cannot attend to one side cannot safely walk, cook, cross a road or drive, however strong their limbs are.

Anosognosia: not knowing

Frequently accompanying neglect, and the hardest feature for families, is anosognosia — a lack of awareness of the deficit itself.

This is not denial in the psychological sense. The person is not refusing to accept bad news. The brain’s capacity to monitor its own performance in that domain is impaired, so there is genuinely no internal signal that anything is wrong. A person may acknowledge in the abstract that they had a stroke and simultaneously insist their left arm is fine while it lies motionless.

Arguing does not work, because you are not arguing with a belief. What tends to work better is demonstration rather than assertion — asking the person to attempt a task and letting the outcome speak — and even then, insight may not generalise.

The consequences are serious and specific: people with poor insight want to drive, want to go home alone, want to return to work, and resist the support they need. They are also at high risk of falls, because they do not account for their own limitations. This is the single most common cause of serious conflict between stroke survivors and their families, and framing it as stubbornness or difficulty makes everything worse.

What helps with neglect

Environmental arrangement, which is the mainstay and immediately useful. Put the plate, the drink, the phone, the call bell and the person you want them to engage with on the affected side, so attending to it is required — but position essential safety items where they will actually be found. Those two principles conflict, and the resolution is that therapy tasks go on the neglected side while safety items go where they will be seen.

Scanning training. Teaching a deliberate, systematic sweep of the environment — turning the head fully left, finding an anchor, working back. It takes practice to become habitual, and it generalises imperfectly.

Cueing, verbal and visual. A coloured line down the left margin of a page gives the eye a target to find. A tap on the left shoulder prompts a turn.

Limb activation. Using or moving the affected limb appears to improve attention to that side.

Approach from the affected side, and say the person’s name before speaking, so they orient.

Prism adaptation and other specific techniques are used in some centres with mixed evidence.

A note for support workers: it is instinctive and kind to put everything within easy reach on the person’s good side. In neglect, that deepens the problem. Ask the therapist where things should go — the answer differs by person and by whether safety or rehabilitation is the priority in that moment.

Executive function

Executive function is the management layer of cognition: planning, organising, initiating, sequencing, switching between tasks, holding a goal in mind, inhibiting inappropriate responses, monitoring your own performance, and judging risk.

It is damaged by strokes in a range of locations, particularly frontal and subcortical, and it is the deficit most likely to be missed entirely, because none of the obvious screening tests detect it. A person can score well on orientation, memory and language, and be unable to run a week of their own life.

What it looks like:

• Cannot plan or sequence a multi-step task — a meal, a load of washing, getting out of the house on time
• Starts things and does not finish them
• Cannot switch between tasks or cope with an interruption
• Does the same thing repeatedly despite it not working
• Poor judgment of risk, including financial risk
• Does not initiate, even when willing
• Does not notice their own errors
• Managing medication, bills and appointments becomes unsafe

This is why the NDIS self-management domain matters so much after stroke, and why it is the domain most often omitted from applications. A person who looks physically recovered and cannot organise their medication, judge a financial decision or run a household has substantially reduced functional capacity, and the only way anybody will know is if the application says so with examples.

Memory, attention and processing speed

Processing speed slows after most strokes, which has knock-on effects everywhere — conversation, reading, driving, decision-making under time pressure.

Divided attention is commonly impaired. The person can walk, or talk, but not both. This is worth knowing because it is a falls risk: talking to someone while they are walking on uneven ground is genuinely unsafe for some stroke survivors.

Memory is affected in some strokes, usually in the encoding and retrieval of new information rather than loss of established memories.

Vascular cognitive impairment is the broader term for cognitive decline from cerebrovascular disease. A single large stroke can cause it; so can an accumulation of small vessel changes. Where it progresses, it becomes vascular dementia, which is the second most common form of dementia and is named on NDIS List B. The critical point for anybody under 65 is that dementia diagnosed before 65 is younger onset dementia, which sits inside the NDIS rather than the aged care system.

Secondary prevention matters here beyond preventing another obvious stroke: controlling blood pressure, cholesterol, diabetes and atrial fibrillation also slows the accumulation of small vessel damage that drives cognitive decline.

Getting it properly assessed

Cognitive change after stroke is under-assessed in Australia, and the screening tools used on the ward are not adequate for it.

Bedside screens such as the MMSE or MoCA are brief and useful for flagging gross impairment. They substantially under-detect executive dysfunction and neglect, and they are confounded by aphasia — a person with language impairment will score badly on a verbal test regardless of their reasoning.

Neuropsychological assessment is the proper instrument: several hours, mapping each domain separately, producing a profile rather than a score. It is the thing to ask for when a consequential decision depends on cognition — driving, return to work, capacity, financial decision-making, or an NDIS application that rests on self-management. Psychology is $252.99 per hour under the 2026–27 NDIS price limits and a full assessment plus report runs to several hours, so it is not trivial, but it is the right spend when a decision turns on it.

Occupational therapy functional cognitive assessment is the complement, and often more useful day to day: watching the person actually attempt a real task — making a cup of tea, following a recipe, managing a shopping trip — and identifying where it breaks down.

Ask for both where possible. A test score tells you what is impaired; a functional assessment tells you what that means on a Tuesday.

What actually helps

The evidence favours compensation over restoration, which is to say: training the strategy and the environment more than training the underlying function.

Externalise everything. One calendar with alarms, on the phone. A whiteboard in the kitchen. A written daily routine. Checklists for multi-step tasks. Medication in a dated blister pack. The aim is to move the executive load out of the person’s head and into the environment.

Reduce decisions through routine. Same order, same time, same place. Routines consume no executive function.

Break tasks into written steps, and make the first step small enough to be startable.

One thing at a time, with interruptions minimised.

Prompting rather than doing. The difference between a support worker who makes the sandwich and one who prompts through each step is the difference between maintenance and rehabilitation.

Error-reduction rather than error-correction for learning new routines — set things up so the person succeeds rather than letting them practise the mistake.

Manage the fatigue, because cognitive performance after stroke falls sharply with fatigue, and a person assessed at 4pm is not the same person who was assessed at 9am. See fatigue and mood after stroke.

Protect financial safety without removing autonomy. Graduated arrangements — a separate account with a limited balance, a second signatory on larger transactions, alerts to a trusted person — preserve control over spending while limiting the consequences of impaired risk judgment. Removing all financial control from a competent adult because of one bad decision is both common and wrong.

Visual field loss, which is not neglect

Worth separating, because the two get confused and the management differs.

Hemianopia is loss of half the visual field in both eyes, caused by damage to the visual pathways behind the eye. The person genuinely cannot see that half. Crucially, most people with hemianopia know something is missing and can compensate by turning the head and scanning.

Neglect is a failure of attention, not of vision. The information arrives and is not processed, and the person typically does not know anything is missing.

Why it matters: hemianopia responds well to scanning training, and many people adapt substantially. Neglect is harder, because you cannot train someone to compensate for something they do not perceive as absent. Someone can have both, which is the worst combination.

Practical implications for either: an optometry or ophthalmology assessment should happen rather than being assumed from the stroke; reading is often affected and a ruler or a finger marking the start of the line helps; and both have serious implications for driving, discussed in driving and work after stroke.

Two other visual problems after stroke are frequently missed. Double vision from eye movement weakness, which is sometimes correctable with prisms or patching. And visual processing problems — difficulty recognising faces or objects, or judging depth and distance — which are not refractive and will not be picked up by a standard eye test.

Capacity, and getting it right

Cognitive change after stroke raises questions about decision-making, and they get handled badly in both directions — autonomy removed from people who have it, and risk ignored in people who do not.

The principles that apply in Australia:

Capacity is presumed until the contrary is established.

Capacity is decision-specific. A person may lack capacity to manage complex finances and retain capacity to decide where they live, who visits, and what medical treatment they accept. A single global finding of incapacity is almost always wrong.

Capacity is not the same as agreeing with you. An unwise decision by a person with capacity is their right.

Communication difficulty is not incapacity. This matters enormously where there is aphasia — the person may need pictures, yes/no, writing or simply time, and still be deciding for themselves.

Supported decision-making comes first. Providing information in an accessible form, allowing time, and involving trusted people is the default. Substituted decision-making — a guardian or administrator appointed by a state tribunal — is a last resort for specific decisions.

Where a formal assessment is needed, a neuropsychological assessment combined with an occupational therapy functional assessment is the usual basis, and it should address specific decisions rather than capacity in general.

Explaining it to other people

A recurring difficulty: the person looks well, so nobody believes there is a problem.

What helps is describing the consequence rather than the deficit. “He has executive dysfunction” means nothing to an employer, a bank or a brother-in-law. “He can do each step of a task but cannot work out the order, so he needs the sequence written down” lands.

Some phrasings that work:

• “The information gets in and gets out, just more slowly — he needs longer to answer, not simpler words.”
• “She can’t see the left side of things, so please come up on her right and say her name first.”
• “He can’t start things on his own. If you ask him to do it he will, happily — he just can’t initiate it.”
• “She’ll agree to anything to be polite. Ask her to tell you the plan back.”

It is also worth having a short written summary — half a page — that can be given to a new GP, a locum, an employer or a hospital. After a stroke people encounter a lot of professionals who have five minutes and no history, and a written profile prevents the same explanation being attempted twenty times by someone who finds explaining difficult.