Stereognosis Test: Definition, Assessment, Kit, Activities, vs. Graphesthesia, vs. Astereognosis

Content:

• What is Stereognosis Test?
• Definition
• Assessment
• Kit
• Activities
• Stereognosis vs. Graphesthesia
• Stereognosis vs. Astereognosis

What is Stereognosis Test?

The Stereognosis Test is a neurological sensory assessment used to evaluate a person’s ability to recognize objects by touch alone, without visual input. During this test, the patient closes their eyes while the examiner places a familiar object—such as a coin, key, or paperclip—into their hand. The patient is then asked to identify the object based solely on tactile information. This test assesses higher cortical sensory processing, particularly within the parietal lobe of the brain.

Stereognosis is an important part of the sensory examination because it goes beyond basic touch sensation. A person may feel pressure, texture, and temperature normally, yet still be unable to recognize objects by touch if cortical integration is impaired. The stereognosis test is commonly used in neurology, physical therapy, and occupational therapy to detect cortical sensory deficits following stroke, brain injury, or neurodegenerative disease.

Definition

Stereognosis is defined as the ability to perceive and recognize the form, shape, size, and texture of objects using the sense of touch. It relies on intact peripheral nerves, spinal pathways, thalamic relays, and cortical processing centers in the brain. This function allows individuals to perform everyday tasks such as finding keys in a pocket or identifying objects in the dark.

Loss or impairment of stereognosis suggests dysfunction in the sensory cortex or its connecting pathways. Importantly, stereognosis is considered a cortical sensory function, not a basic sensation. This means that even when light touch and pain sensation are preserved, stereognosis may still be abnormal. Identifying this deficit helps clinicians localize neurological damage more precisely.

Assessment

Assessment of stereognosis is typically performed as part of a comprehensive neurological examination. The examiner asks the patient to close their eyes or look away, then places a small, familiar object into one hand at a time. The patient is allowed to manipulate the object using their fingers but not their other hand or vision. The response is compared between both hands to detect asymmetry.

Abnormal results may indicate lesions in the contralateral parietal lobe, peripheral neuropathy, or spinal cord disease. Clinicians must ensure that basic sensations such as touch and proprioception are intact before interpreting stereognosis results. If the patient cannot feel the object at all, the issue may not be cortical but rather peripheral or spinal in origin.

Kit

A stereognosis test kit typically includes a set of small, everyday objects with varying shapes and textures. Common items include coins, keys, buttons, marbles, paper clips, screws, and small blocks. Some clinical kits are standardized for occupational therapy or neurological assessment, making testing more consistent and reproducible.

In therapy settings, kits may be adapted to the patient’s age and cognitive level. Pediatric kits often include toy shapes, letters, or textured objects, while adult kits focus on practical items. Using a consistent set of objects helps track progress over time, especially in rehabilitation following stroke or hand injuries.

Activities

Stereognosis activities are commonly used in rehabilitation to improve sensory integration and hand function. These activities involve identifying objects hidden in a bag, sorting items by shape or size without vision, or matching objects using touch alone. Such exercises help retrain the brain’s ability to process tactile information.

Occupational therapists frequently incorporate stereognosis activities into daily functional tasks. For example, patients may practice finding coins in a purse or identifying utensils in a drawer. These activities not only enhance sensory recovery but also improve independence in daily living, especially after neurological injury.

Stereognosis vs. Graphesthesia

Stereognosis and graphesthesia are both cortical sensory functions, but they assess different abilities. Graphesthesia refers to the ability to recognize numbers or letters traced on the skin, usually on the palm, without visual input. While stereognosis focuses on object recognition, graphesthesia evaluates symbolic sensory processing.

Both tests help localize parietal lobe dysfunction, and they are often performed together during a sensory examination. A patient may have impaired graphesthesia with preserved stereognosis, or vice versa, depending on the nature and location of the brain lesion. Using both tests provides a more complete picture of cortical sensory function.

Stereognosis vs. Astereognosis

Astereognosis is the inability to recognize objects by touch despite intact basic sensation. It is essentially the pathological counterpart of stereognosis. Patients with astereognosis can feel the object but cannot identify it, indicating a cortical processing deficit rather than a loss of touch.

Astereognosis is commonly seen in parietal lobe lesions, strokes, tumors, or advanced neurodegenerative conditions. Identifying astereognosis during testing is clinically significant because it helps differentiate between peripheral sensory loss and higher-level cortical dysfunction. This distinction is crucial for diagnosis, treatment planning, and rehabilitation strategies.