Neurologic Exam-Pediatric | 3-month-old | Normal | Primitive Reflexes - Asymmetric Tonic Neck

3-month-old - Normal 17 - Primitive Reflexes - Asymmetric Tonic Neck: The asymmetric tonic neck reflex is present in the first 3 to 4 months of life. When the head is turned to one side, the ipsilateral arm and leg will extend while the contralateral extremities will be in flexion. The baby should be able to overcome this reflex and move out of this posture. If the asymmetric reflex is obligate (the infant can not move out of or overcome the reflex) or if the reflex persists beyond 6 months of age, then it is abnormal and can be seen in upper motor neuron disorders.