The parietal lobes sit near the top and back of the head, and most of their work is interpretation. They take raw signals from touch, the body, and vision and turn them into a sense of where things are and how to act on them. Damage there rarely causes plain numbness or weakness. It causes trouble recognizing, locating, and using things.
Which side is damaged largely decides what that trouble looks like, so two people with “parietal lesions” can seem to have entirely different illnesses.1PubMed. The history of the neurophysiology and neurology of the parietal lobe Some of the most striking symptoms are ones the person cannot notice in themselves, which is why family members often spot them first.2PubMed. Anosognosia in parietal lobe syndrome
Changes in Touch and Body Sense
Damage to the front part of the parietal lobe tends to cause a “cortical sensory loss.” The person can feel being touched but cannot work out what is touching them.3PubMed Central. Clinical assessment of parietal lobe function They may be unable to identify a key or coin in their hand by feel alone, recognize a number traced on their palm, tell textures apart, or sense where a limb is without looking.4PubMed Central. Clinical assessment of parietal lobe function These problems appear on the side of the body opposite the damage and are usually more obvious in the arm than the leg.5PubMed Central. Clinical assessment of parietal lobe function
At home, this looks like fumbling for keys or change in a pocket without glancing down. Things get dropped because the hand gives poor feedback about grip. The clumsiness often eases when the person watches their hand, and they may not notice that the hand has ended up in an awkward or unsafe position.
This is not simple numbness. The signals still arrive; what fails is combining them into a shape, a texture, or a position. A quick check with a pin or light touch can come back normal, because the person still feels the contact. If clumsiness continues despite a normal basic exam, it is reasonable to ask for tests of object recognition and limb position sense.
Pain and temperature sense are usually less affected than fine touch.6PubMed. The history of the neurophysiology and neurology of the parietal lobe Damage deep in the parietal region near the insula can, however, lead to constant burning or ice-like pain across one half of the body.7JAMA Neurology. Parietal Pseudothalamic Pain Syndrome: Clinical Features and Anatomic Correlates That pain often comes with reduced ability to feel pinprick and temperature on the same side.8PubMed. Pain syndromes and the parietal lobe New, unexplained burning pain on one side after a parietal stroke is worth reporting, since central pain is a recognized complication.
Why the Side of the Damage Matters
The back part of the parietal lobe combines information from several senses to build a map of the body and surrounding space, used for attention and action.9PubMed. The history of the neurophysiology and neurology of the parietal lobe The two halves then specialize. In most right-handed people the left side handles language, so “dominant” in a report usually means left. Left-side damage therefore tends to show up in writing, reading, maths, and skilled movements, while right-side damage shows up in attention to space and the body.
Right-Side Damage Neglect and Unawareness
Neglect means failing to notice or respond to things on one side of space, most often the left after right-brain damage.10PubMed. Neuroanatomy of hemispatial neglect and its functional components: a study using voxel-based lesion-symptom mapping About half of people with a right-hemisphere stroke show it.11PubMed. Hemispatial neglect: Subtypes, neuroanatomy, and disability The lower parietal area on the right is a key region for this spatial attention,12PubMed. Neuroanatomy of hemispatial neglect and its functional components: a study using voxel-based lesion-symptom mapping though damage to connected frontal and parietal regions can produce neglect too.13PubMed. Visual extinction in relation to visuospatial neglect after right-hemispheric stroke: quantitative assessment and statistical lesion-symptom mapping
Day to day, a person may eat only the food on the right half of the plate and seem puzzled that they are still hungry. Grooming can be one-sided, such as shaving or applying makeup on only the right side of the face. They may bump into door frames or furniture on the left and miss objects on that side of the table. People standing on the left may go unanswered, which can look like rudeness or poor hearing but isn’t.
Neglect is not blindness; the eyes may work normally. Turning attention to the left can briefly bring things back, and a competing object on the right makes left-sided items vanish more easily.
People with right parietal damage often deny that a limb is paralysed.14PubMed. Anosognosia in parietal lobe syndrome In one series, patients kept choosing two-handed tasks like tying shoelaces and showed no frustration after failing repeatedly.15PubMed. Anosognosia in parietal lobe syndrome Related problems include indifference to the illness, a feeling that a limb doesn’t belong to them, or a sense of an extra limb.16PubMed Central. Beliefs in Right Hemisphere Syndromes: From Denial to Distortion
Arguing with unawareness rarely works, because the brain’s own body map is affected rather than the person being stubborn. Safety risks rise because they attempt tasks they can’t do, so gentle cues and supervision work better than persuasion.
Even without neglect, right parietal damage can weaken short-term memory for what was just seen, both locations and objects.17PubMed Central. The right parietal lobe is critical for visual working memory
Left-Side Damage Words Numbers and Actions
Damage in the lower part of the left parietal lobe can cause four linked problems: trouble writing, trouble with arithmetic, confusing left and right, and inability to name or identify fingers.18BrainFacts.org. Gerstmann’s Syndrome Together these are known as Gerstmann’s syndrome, and it can follow a stroke or other parietal damage.19BrainFacts.org. Gerstmann’s Syndrome Not everyone shows all four.
Damage in the lower left parietal lobe and the wiring beneath it can cause loss of both reading and writing.20PubMed. Damage to the Upper Portion of Area 19 and the Deep White Matter in the Left Inferior Parietal Lobe, Including the Superior Longitudinal Fasciculus, Results in Alexia with Agraphia Unlike some reading problems, where a person can still write words they then cannot read back, here writing is lost along with reading.
In daily life, writing a shopping list or signing a name may become hard or produce jumbled letters, even though the hand is strong. Handling change, paying bills, or keeping track of a phone number can suddenly become confusing for someone who managed easily before. Directions such as “turn left” and “turn right” may be mixed up, and naming which finger is which can fail.
Left parietal damage can also cause apraxia: trouble carrying out learned movements, such as miming tool use or copying a gesture, despite normal strength.21PubMed Central. Limb apraxia and the left parietal lobe A toothbrush or fork may be used awkwardly. The muscles work, but the movement plan goes wrong. Actions may go better automatically than on command, and the whole picture can look like confusion when it isn’t.
Damage on Both Sides Vision and Reaching
Damage to both parietal lobes can produce three problems: seeing only one object at a time, reaching inaccurately for what is seen, and trouble moving the eyes to a target.22PubMed. Bilateral parietal dysfunctions and disconnections in simultanagnosia and Bálint syndrome When severe, this combination is called Bálint syndrome; the brain can’t use visual space to guide the arm or eyes.23Wikipedia. Two-streams hypothesis Milder forms affect walking down steps, moving through crowds, and grasping,24Perkins School for the Blind. Higher-order visual pathways and the CVI brain and the features can occur singly or together.25PubMed Central. Impact of Cerebral Visual Impairments on Motor Skills: Implications for Developmental Coordination Disorders
A person may miss a cup when reaching for it, especially when it is off to the side, even though they can see it clearly. They may see a fork but not the plate around it, because they can take in only one object at a time. In busy places such as shops or stations they can become lost, since the whole scene never comes together. Their eyes may seem “stuck” on one item and struggle to shift to a new target.
Standard eye tests can still be normal. The eyes and sharpness of vision may be fine, because the problem lies in interpreting space. Assessment by a neurologist or neuro-optometrist is the place to ask for.
How Doctors Check for Parietal Symptoms
Doctors check touch by placing objects in the hand with the eyes closed and tracing numbers on the palm.26PubMed Central. Clinical assessment of parietal lobe function Neglect is tested by asking the person to cross out marks across a page or mark the middle of a line.27PubMed Central. Testing for Spatial Neglect with Line Bisection and Target Cancellation: Are Both Tasks Really Unrelated? These two tasks pick up somewhat different parts of the problem, so both are often used.28PubMed. Visual extinction in relation to visuospatial neglect after right-hemispheric stroke: quantitative assessment and statistical lesion-symptom mapping Brain imaging shows where the damage is.
The rest of the appointment is usually simple. The person may be asked to copy a drawing or draw a clock face, which shows problems with space and attention. They may be asked to name fingers, point to left and right, or mime using a comb or key. A written sentence and some simple sums check the left-side skills of writing and numbers. Family can help by reporting specific everyday incidents, especially problems the person doesn’t notice, and when the changes started.
Recovery and Treatment
Prism adaptation uses glasses that shift vision to the right while the person does short daily pointing exercises.29PubMed Central. Prism adaptation and spatial neglect: the need for dose-finding studies At first they point too far to the right, then adjust until they hit the targets, and this adjustment appears to retrain attention toward the left. It can improve neglect, with benefits for tasks like dressing lasting 6 months or more.30PubMed Central. Prism adaptation and spatial neglect: the need for dose-finding studies People whose damage spares the parietal lobe tend to benefit more than those with parietal damage itself.31PubMed. Prism adaptation effect on neural activity and spatial neglect depend on brain lesion site
Other rehabilitation works on real life. Occupational therapy practises tasks such as dressing and cooking, using strategies to compensate for what is lost. For neglect, therapists teach cueing, such as placing a bright line or object on the left edge to remind the person to look that way. For apraxia, practising the real task in its normal setting tends to help more than drilling isolated movements. Speech and language therapy can address reading and writing difficulties after left-side damage.
At home, approach the person and place items on the good side early on, then gradually move things toward the neglected side. Remove trip hazards, and supervise decisions about cooking and driving.
Parietal Damage in Children
In children, damage can reduce feeling down the opposite side, making them less aware of that part of the body.32The Royal Children’s Hospital Melbourne. Brain injury – an overview Visual-spatial damage can make reaching and eye movements inaccurate, sometimes mistaken for clumsiness.33PubMed Central. Impact of Cerebral Visual Impairments on Motor Skills: Implications for Developmental Coordination Disorders
A child may ignore one hand during play, using only the other even though the hand is strong. They may have trouble with stairs or catching balls, because judging space and guiding movement is difficult. They may struggle to find a toy in a cluttered box, since a crowded scene is hard to take in. If these signs appear, ask about an assessment for cerebral visual impairment.