“C3, 4, 5 Keeps the Diaphragm Alive.” Is Phrenic Nerve Palsy Part of the Pathophysiological Mechanism in Strangulation and Hanging? Should Diaphragm Paralysis be Excluded in Survived Cases?

Abstract

The phrenic nerve arises in the neck. It is formed from C3, C4, and C5 nerve fibers and descends along the anterior surface of the scalenus anterior muscle before entering the thorax to supply motor and sensory input to the diaphragm. Its anatomic location in the neck leaves the nerve vulnerable to traumatic injury. Phrenic nerve injury can arise as a result of transection, stretching or compression of the nerve, and may result in paralysis of the diaphragm. Consequences of diaphragm paralysis include respiratory compromise, gastrointestinal obstruction, and cardiac arrhythmias. There may be serious morbidity and onset of symptoms may be delayed. Cases of diaphragm paralysis occurring as a consequence of neck trauma are documented in the literature. In some cases, the forces involved are relatively minor and include whiplash injury, occurring in minor motor vehicle collisions, chiropractic manipulation, and compression of neck structures, including a case involving external neck compression by industrial machinery. It is concluded that phrenic nerve palsy might be part of the pathophysiological mechanism in strangulation and hanging, and clinical investigation to exclude diaphragm paralysis in survived cases should be considered.

Death caused by cardioinhibitory reflex cardiac arrest—A systematic review of cases

“…Circumstances of death and the known duration and time sequence of events are therefore essential to help experts distinguish CiRCA from other mechanism such as commotio cordis [44,45], contention gagging, vagal mediated cardiac arrest [46], phrenic paralysis [47], or other causes of sudden death such as arrhythmias resulting from channelopathies or excited delirium alone (Table 3) [40][41][42][43].…”

Accidental Strangulation with Cervical Nerve Root Injury Caused by the Entrapment of Clothing in a Soybean Milling Machine

“…Cervical nerve root injury in survivors of accidental strangulation is a rare event. Strangulation can injure the soft tissues of the neck; the larynx, trachea, esophagus, and cervical spine; and the nerves located in the neck, which include the laryngeal, facial, and phrenic nerves [8, 9]. These injuries may not be immediately apparent [10].…”

Possible death mechanisms other than respiratory asphyxia in a suicidal hanging case

“…At this point diaphragmatic paralysis due to compression of phrenic nerve, originating from 3 rd , 4 th and 5 th cervical nerve roots, could be blamed but there was no proven hypothesis to explain this kind of death mechanism in literature [22,23].…”