Sensory Alteration 👂
Deprivation vs overload · hearing aids · vision loss · aphasia
Too little input and too much input produce the same picture — confusion, irritability, disorientation. What tells them apart is the environment she is in, and that is what the questions test.
🧨 What starts it
- Sensory deprivation — not enough meaningful stimulation. A patient in isolation, on bed rest, with poor vision and hearing, in a quiet single room. She becomes drowsy, bored, withdrawn, then disoriented, and can hallucinate.
- Sensory overload — too much, unable to filter it. The classic setting is intensive care: alarms, lights, constant interruptions, pain, no sleep. She becomes restless, irritable, unable to concentrate, with racing thoughts.
- Both end in confusion, so look at the environment to tell which one it is.
- Older adults with reduced hearing, vision, taste and touch
- Anyone in isolation or on prolonged bed rest
- Intensive care patients, and anyone intubated or restrained
- Stroke patients with a visual field loss or neglect
- People who cannot use their aids — glasses left at home, a hearing aid with a flat battery
Give her back her glasses and hearing aid. An enormous share of “acute confusion” in an older adult is simply someone who cannot see or hear what is happening. Check for them before anything else.
🔎 What you will see
- For deprivation: increase meaningful input. Open the curtains, a clock and a calendar in view, radio or television she chooses, familiar objects from home, regular conversation, visitors, get her out of the room.
- For overload: reduce and cluster. Turn down alarms and lights, close the door, cluster care so she gets uninterrupted sleep, one person speaking at a time, simple short instructions, quiet periods.
- Both benefit from orientation — say your name, the day and where she is, every time you enter.
- Turn it off and open the battery door when it is out — that is what makes the battery last.
- Store it in a dry, safe container, away from heat and direct sun. Never in water.
- Clean the mold with a dry soft cloth; a wax loop for the opening. No alcohol, no solvents, never submerge it.
- Whistling means it is not seated properly or the volume is too high.
- Insert it with the volume low, then turn it up.
- Remove it before showering, swimming, or a hair dryer.
- Face her, at eye level, with the light on your face, not behind you.
- Speak normally and slightly slower. Do not shout — it distorts the sound and raises the pitch, which is the range she has already lost.
- Lower your pitch rather than raising your volume.
- Reduce background noise. One person at a time.
- Rephrase rather than repeat the same words louder.
- Use writing or a picture board, and a certified interpreter for sign language.
🔬 The tests
What each one looks like, how it is done, and what the result means. The pictures are the point — if you can picture the maneuver you can usually reason out the answer.
Hearing
Whisper test
How: Stand 1–2 ft behind her so she cannot read your lips. Press and rub the tragus of the other ear to block it. Breathe all the way out, then whisper three letters and numbers — “6–K–2”. Repeat with a different set for the other ear.
Normal: Repeats at least three of six items correctly.
Abnormal: Cannot repeat them — refer for audiometry. Do not keep raising your voice until she passes.
Weber test
How: Strike a 512 Hz fork on the heel of your hand and stand the base on the middle of her forehead, or the top of her head. Ask where she hears it, not whether.
Normal: Heard equally in both ears. No lateralization.
Abnormal: Lateralizes to the bad ear = conductive loss on that side (wax, fluid, a perforation) — the block keeps room noise out, so bone-conducted sound seems louder. Lateralizes to the good ear = sensorineural loss in the quiet ear.
Rinne test
How: Strike the fork, put the base on the mastoid and ask her to say when it stops. Immediately move the prongs 1–2 cm from the ear canal and ask whether she can still hear it.
Normal: Still hears it in the air after the bone sound has gone — air conduction beats bone conduction, roughly 2 to 1. This is a positive Rinne, and positive is normal.
Abnormal: Bone equal to or better than air = conductive loss. Both shortened but air still better = sensorineural loss.
Otoscopic exam
How: Adult or child over 3: pull the pinna up and back. Child under 3: down and back. Brace your hand against her head so a sudden movement moves the scope with her, and insert 1–1.5 cm angled down and forward.
Normal: Pearly gray, translucent, slightly concave, with the malleus visible and a cone of light at 5 o’clock in the right ear, 7 o’clock in the left.
Abnormal: Red, bulging, landmarks gone = acute otitis media. Dull, retracted, a fluid line or bubbles = otitis media with effusion. Perforation, wax plug or a foreign body will also block conduction.
Vision
Snellen chart — distance acuity
How: Stand her 20 feet from the chart, cover one eye at a time, and leave her glasses or contacts on — this is corrected acuity. Record the smallest line she can read.
Normal: 20/20. Note misses as she goes: 20/40 −2 means she read the 20/40 line but missed two letters.
Abnormal: The bigger the bottom number, the worse the vision: 20/40 means she sees at 20 feet what a normal eye sees at 40. Worse than 20/200 in the better eye, corrected, is legal blindness.
Near vision card
How: Hold a Rosenbaum or Jaeger card 14 inches away, one eye at a time, reading glasses on.
Normal: 14/14, or reads the smallest line comfortably.
Abnormal: Has to push the card further away to focus — presbyopia, which starts around 40 and is not a disease.
Confrontation visual fields
How: Sit about 2 ft away at her eye level. She covers her left eye, you cover your right. Both stare at each other’s nose. Bring a wiggling finger in from each of the four corners, midway between the two of you, and ask her to say the moment she sees it. Then swap eyes.
Normal: She sees the finger at the same moment you do — you are the control, which is why your own fields have to be normal.
Abnormal: A field cut. Losing the same half of the field in both eyes (homonymous hemianopsia) is typical after a stroke.
Six cardinal fields of gaze
How: Hold your finger about 12 inches away. Ask her to hold her head still and follow it with her eyes only, while you trace a wide H. Watch both eyes together, and pause at each corner.
Normal: Smooth, conjugate movement in all six directions. A couple of beats of nystagmus at the extreme edge is normal.
Abnormal: One eye lagging or not reaching a corner = a palsy of CN III, IV or VI. Sustained nystagmus or double vision is abnormal anywhere.
Pupils — PERRLA
How: Dim the room and ask her to look at something far away. Bring the penlight in from the side, never straight at her. Watch the lit pupil (direct) and the other one (consensual). Then hold a finger far away and move it toward her nose for accommodation.
Normal: Pupils Equal, Round, Reactive to Light and Accommodation. 2–6 mm, brisk. About one person in five has a small harmless difference in size.
Abnormal: A new unequal pupil, a sluggish one, or a fixed dilated pupil after a head injury means rising pressure in the skull — that is an emergency, not an assessment finding to chart and move on from. Pinpoint pupils suggest opioids.
Touch, vibration and position
Light touch
How: Eyes closed. Brush a wisp of cotton on the skin at irregular intervals so she cannot predict the rhythm, and ask her to say “now” each time. Compare left with right, and hands and feet with the trunk.
Normal: Feels every touch, and the two sides feel the same.
Abnormal: Glove-and-stocking loss = peripheral neuropathy. Loss in one band = a nerve root. Loss down one whole side = central, usually a stroke.
Sharp versus dull
How: Snap a tongue blade in half — one end is now sharp, the other blunt. Eyes closed, alternate them at random and ask “sharp or dull?” each time.
Normal: Identifies both correctly and consistently.
Abnormal: Cannot tell them apart, or feels neither — loss of pain and temperature sensation.
Vibration
How: Strike a 128 Hz fork and press the base on a bony point — the joint of the great toe, the medial malleolus, a knuckle. Ask her to say when the buzzing stops. Then damp it with your fingers while it is still on her skin, to check she is not guessing.
Normal: Feels the buzz, and says it has stopped at about the moment it actually does.
Abnormal: Cannot feel it, or loses it well before you do. Vibration is one of the first senses to go in diabetic peripheral neuropathy and in B12 deficiency.
Position sense (proprioception)
How: Hold the great toe by its sides, not its top and bottom — pressure on the nail bed tells her the answer without any position sense at all. Move it clearly up or down, eyes closed, and ask which way.
Normal: Correct every time, at the toe and at a finger.
Abnormal: Gets it wrong, or needs a big movement to tell. Position sense travels in the posterior columns, the same tract as vibration, so the two are usually lost together.
Romberg test
How: Feet together, arms at her sides. Eyes open for 20 seconds, then eyes closed for 20 seconds. Stand close with your arms ready — a positive Romberg means she falls.
Normal: Slight sway with the eyes shut, and she stays up.
Abnormal: Positive: she sways badly or falls only once the eyes close. She was using vision to stand up straight, and the proprioception or vestibular input underneath was gone.
10-g monofilament
How: Eyes closed. Hold the filament perpendicular to the skin and press until it buckles into a C — that bend is what makes it exactly 10 grams. Hold about a second, then lift. Test the sites in no fixed order, and throw in a couple of moments where you touch nothing.
Normal: Feels the filament at every site tested.
Abnormal: Any site not felt = protective sensation lost. She can stand on a tack, or wear a shoe that is rubbing a hole in her foot, and never know.
Cortical — the parietal lobe
Stereognosis
How: Eyes closed. Put a familiar object in her hand — a key, a coin, a paper clip, a button — and let her turn it over.
Normal: Names it within a few seconds.
Abnormal: Astereognosis. Note that this only counts when plain touch is normal: if she cannot feel the object at all, the problem is the nerve, not the parietal lobe.
Graphesthesia
How: Eyes closed. With the blunt end of a pen, draw a number 3–6 cm tall on her palm, the right way up from her point of view, and ask her what you wrote.
Normal: Identifies the number.
Abnormal: Agraphesthesia — again, parietal, and again only meaningful if plain touch is intact.
Two-point discrimination
How: Use a caliper, or the two ends of an opened paper clip. Eyes closed. Alternate touching with one point and with two, narrowing the gap until she can no longer tell two from one.
Normal: Fingertip 2–5 mm, palm 8–12 mm, back 40 mm or more. The number varies hugely by body part, so always compare with the same spot on the other side.
Abnormal: A distance much wider than the matching spot on her other side.
Extinction (double simultaneous touch)
How: Eyes closed. Touch both sides at the same instant — both forearms, both cheeks — and ask how many places you touched and where. Check each side alone first, so you know plain touch is intact.
Normal: Reports both touches, on both sides.
Abnormal: Extinction: she feels only one side, even though that same side is felt normally when touched on its own. It is the classic sign of neglect, usually after a right-hemisphere stroke, and it goes with a left-sided field cut.
Smell and taste
Smell — CN I
How: Eyes closed. Press one nostril shut and hold a familiar, non-irritating smell under the other — coffee, vanilla, soap, orange. Repeat on the other side with a different smell.
Normal: Detects and usually names it on both sides.
Abnormal: Anosmia. Common after a head injury (the olfactory fibers shear as they pass through the skull base), with nasal disease, with age, and as an early sign in Parkinson’s and Alzheimer’s disease.
Taste — CN VII and IX
How: Eyes closed, tongue out. Place a small amount of a test substance on the front two thirds (CN VII, facial), then on the back third (CN IX, glossopharyngeal). Rinse with water between each one.
Normal: Identifies sweet, salty, sour and bitter.
Abnormal: Loss on the front two thirds points at the facial nerve — Bell’s palsy affects taste as well as movement. Taste is also blunted by chemotherapy, radiation, dry mouth and many medications.
🩺 What you do
- Announce yourself when you enter and say when you leave — otherwise she is talking to an empty room.
- Explain what you are about to do before touching her.
- Keep everything in the same place and tell her if you move something.
- Sighted-guide technique: she takes your arm just above the elbow and walks half a step behind. You do not take hers.
- Describe the meal tray as a clock face — potatoes at three, meat at six.
- At home: remove rugs and clutter, tape down cords, good lighting, contrasting colors on step edges, grab rails.
- Expressive (Broca’s): she knows what she means and cannot get it out. Speech is effortful and short. She is aware of it and it is deeply frustrating. Give her time, do not finish her sentences, use yes-or-no questions and a picture board.
- Receptive (Wernicke’s): she speaks fluently but the words do not make sense, and she does not understand you. Use short simple sentences, gestures and demonstration. Confirm understanding by what she does, not what she says.
- Global: both. Use touch, gesture and consistency.
- Speak to her as an adult. Aphasia is not a loss of intelligence.
- Glasses and hearing aid — are they in, and do they work?
- Oxygen — hypoxia presents as confusion before anything else.
- Glucose, electrolytes, infection — a urinary tract infection is the classic cause of sudden confusion in an older adult.
- Medications — anticholinergics, sedatives, opioids.
- Pain, a full bladder, constipation, no sleep.
Do not label it dementia. Sudden confusion is delirium and delirium has a cause.