Palmar chin skin reflex: signs, symptoms and causes

Description

The palmar-chin skin reflex is characterized by a literal tug of the chin muscle resulting in the lower lip protruding anteriorly or wrinkled, as the examiner traces the skin of the patient's female tissue. The hand-chin skin reflex is a common primary reflex in infants. The reflex that reappears later is due to disease in the frontal lobe or due to age.

Causes

Common

Physiologic.

The weakness of Alzheimer's.

Forehead-temporal dementia.

Dementia circuit.

Less common

Parkinson disease.

HIV / AIDS.

Mechanism

The mechanism for re-emergence of the palmar-chin skin reflex is unknown. The reflexes appear to be controlled by the non-primary motor cortex, controlling the inhibitory effect of the myeloid reflex. Damage to this area can cause loss of inhibition and lead to a 'release' of the reflex.

Meaning

In a study of 39 patients with unilateral hand-chin skin reflex, bilateral hemisphere lesions were detected 44%, bilateral lesions were 36%, bilateral lesions 10%, and no 10% damage. The site of the reflex is not aligned with the site of injury. The hand-chin skin reflex can be detected in about 3–70% of normal cases.