Hypästhesie

Hypästhesie, or hypesthesia, refers to a reduced or diminished sensitivity to sensory stimuli in a defined area of skin. It denotes a partial loss of tactile perception, and may involve decreased ability to feel light touch, as well as changes in temperature or pain sensation. It is distinct from anesthesia, which is a complete loss of sensation, and from hyperästhesie, which is an increased sensitivity.

Causes of hypästhesie are diverse and often reflect underlying nerve pathology. Common sources include peripheral neuropathies (such as diabetic or alcohol-related neuropathy), radiculopathy and nerve entrapment syndromes (for example carpal tunnel), peripheral nerve injuries from trauma or surgery, and demyelinating diseases. Central nervous system processes, including stroke or multiple sclerosis, can also produce regional hypästhesie. Metabolic deficiencies and infections may contribute in some cases.

Clinical assessment involves a neurologic examination focused on sensory function. Key tests include Semmes-Weinstein monofilament testing to gauge light touch perception, two-point discrimination to assess spatial acuity, and evaluations of temperature and pain sensation. Mapping of affected areas helps localize the lesion. Imaging and nerve studies may be used when indicated to identify structural causes.

Differential diagnosis includes anesthesia (complete loss of sensation), hyperästhesie (increased sensitivity), paresthesie (abnormal tingling or “pins and needles”), and dysästhesie (unpleasant distorted sensation). Distinguishing among these states guides evaluation and management.

Management targets the underlying cause and, when appropriate, symptomatic relief. Approaches include management of metabolic or systemic conditions, decompression or repair of nerve injuries, and rehabilitation. Safety measures and protective skin care are important to prevent injury in areas of reduced sensitivity. Prognosis varies with etiology and timeliness of treatment.