A note on Claude Bernard-Horner's syndrome

Pourfour du Petit (1664-1741)

François Pourfour du Petit was a Parisian experimental neuro-anatomist, and ophthalmologist, who investigated his extensive wartime experiences of brain and spinal injuries and verified his conclusions by animal experiments. His results showed with great originality that brain injuries caused weakness or paralysis of the opposite limbs. He also clarified the anatomy of the spinal cord and decussation of the pyramidal tracts, and demonstrated the anatomy and clinical significance of the cervical sympathetic chain.

Pourfour Du Petit and the cervical sympathetic nerves

François Pourfour du Petit (1664-1741) was a Parisian experimental Neuroanatomist, and Ophthalmologist. Based on his extensive experiences of brain and spinal injuries as a military doctor in the armies of Louis XIV he performed many animal experiments that demonstrated the anatomy and functional significance of the cervical sympathetic nerves, correcting previous errors of Thomas Willis and Raymond Vieussens. He long predated the descriptions of Horner’s syndrome (1869) when he showed that interruption of sympathetic pathways inactivated both the dilator muscle and produces miosis, and the superior tarsal muscle, which produces ptosis and enophthalmos. This was later elaborated by Hare, Weir Mitchell and Claude Bernard.

Segmental thoracic epidural anaesthesia in a dog undergoing intercostal thoracotomy and lung lobectomy

A seven-year-old, 25-kg female crossbreed dog received segmental thoracic epidural anaesthesia for left lateral thoracotomy and lung lobectomy. At presentation mild exercise intolerance and weight loss were reported. A chest CT scan revealed a solitary soft tissue mass in the left caudal lobe. Lung lobectomy surgery was scheduled. Under isoflurane anaesthesia, an epidural catheter was threaded through T13–L1 and advanced 50 mm cranially. Bupivacaine and morphine were administered 30 minutes before incision and at 12-hour intervals thereafter. To minimise side effects, the postoperative dose was titrated to guarantee segmental analgesia. Purposeful movements and signs of sympathetic stimulation in response to surgery were not observed. Intraoperatively, a transient 13% increase in arterial blood pressure occurred, while heart rate remained stable compared with baseline. Although the intended postoperative dose was decreased to prevent side effects, pain scores were below the analgesic intervention score. The catheter was removed on the fourth postoperative day. Complications and neurological sequelae were not noticed.

Acute Horner syndrome due to thoracic epidural analgesia in a paediatric patient

A 4-year-old boy with coarctation of the aorta underwent surgical aortic arch repair with general anaesthesia and thoracic epidural analgesia. In the immediate postoperative period, the child developed a unilateral Horner syndrome which appeared to be related to the epidural infusion rate. Management of this patient as well as alternate aetiologies of Horner syndrome are described. Horner syndrome is a rare complication of epidural catheters and is often unrecognized, especially in children.

Horner's syndrome revisited: with an update of the central pathway

A brief summary is presented of the life of Johann Friedrich Horner, the eminent Swiss ophthalmologist, renowned for describing the effects of paralysis of the human cervical sympathetic nerves. His early education, the quality of his professional training, and the influence of his mentors, notably Carl Ludwig and Albrecht von Graefe, contributed to his discovery of the syndrome. The full text of Horner's original work (translated by J. F. Fulton, 1929a, Arch. Surg. 18:2025-2039) is cited. The history of clinical and experimental work carried out on the autonomic nervous system prior to Horner's discovery is reviewed, including the studies of Pourfour du Petit (cited in Fulton, 1929a and Singer and Underwood, 1962, Clarendon); Hare, 1838, Lond. Med. Gaz. 23:16-18; Bernard (cited by Singer and Underwood); Budge (1853, Acad. de Sci., p.377-378); Mitchell et al. (1864, Lippincott). Hare and Mitchell et al. came close to making the discovery but were apparently hindered by their inability to interpret the signs they elicited in their patients. The experiments of Claude Bernard gave succinct accounts of the effects of damage to the cervical sympathetic nerves in animals, although there appears to be no evidence that he made similar observations in humans. Horner was the first to give a detailed, scientifically supported account and accurately interpret the signs of cervical sympathetic nerve damage in a human subject. The anatomy of the pathway is reviewed and the detailed structure of its central part updated. Evidence from computerized tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and single-photon-emission computerized tomography (SPECT) studies have confirmed that reciprocally connected centers in the insular cortex, central nucleus of amygdala, hypothalamus, mesencephalic and pontine tegmentum, nucleus of tractus solitarius, and the ventrolateral medulla form the central pathway. The nucleus of tractus solitarius is probably the main reflex center for the sympathetic system, whereas the ventrolateral medulla serves as the pathway through which the central neurons influence the preganglionic neurons of the thoracolumbar outflow. Emotional and sensory inputs from the frontal and somatosensory cortices provide the inputs needed by the insula to drive the sympathetic nervous system to produce appropriate responses.