astereognosis
Pronunciation: ay-ster-ee-og-NO-sis
Inability to identify objects by touch despite intact basic tactile sensation.
Full Definition
Astereognosis is a form of tactile agnosia characterized by the inability to recognize objects through touch alone, despite preserved elementary tactile sensations such as pressure, temperature, and vibration. This condition typically results from lesions in the parietal lobe, particularly the secondary somatosensory areas. Patients can feel that an object is present and may describe its basic properties (rough, smooth, hard, soft) but cannot integrate these sensations to identify the object. Astereognosis is distinguished from simple sensory loss and is an important sign of cortical dysfunction.
Usage
Usage note: Sometimes written as a-stereognosis; both forms are acceptable.
In Context
- "Testing revealed astereognosis in the patient's left hand following the parietal stroke." — Neurological examination findings
- "The presence of astereognosis suggested cortical rather than peripheral nerve involvement." — Differential diagnosis discussion