Violent shaking may be haphazard or, as in the case of Israel, systematic and planned. In such cases, bruising may be found on the chest or shoulders where the victim was seized but otherwise there are few outward signs. In the acute phase there is usually headache, disorientation and often a changed mental state. The most severe cases demonstrate all the features, potentially fatal, that have been well documented in shaken infant syndrome – cerebral oedema, subdural haematoma and retinal haemorrhage, the last being the major sign that makes possible a diagnosis before death. It has been named the shaken adult syndrome.
Non-fatal brain trauma from violent shaking can potentially result in more subtle but clinically significant cognitive impairment possibly due to diffuse axonal injury, injury to the brain cells themselves. Non-fatal consequences of shaking may also include recurrent headaches, disorientation and mental status changes, all of which can become chronic. Violent shaking can also produce neck trauma, producing a whiplash mechanism of cervical strain. Cervical spine fracture with spinal cord compression may also occur, resulting in quadriplegia.