J Neurol Neurosurg Psychiatry 2001;70:127–129 127 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.70.1.127 on 1 January 2001. Downloaded from SHORT REPORT Isolated medulla oblongata function after severe traumatic brain injury E F M Wijdicks, J L D Atkinson, H Okazaki Abstract reflexes were absent. Brain CT documented a The objective was to report the first large left epidural supratentorial haematoma in pathologically confirmed case of partly addition to subarachnoid blood in the basal functionally preserved medulla oblongata cisterns and fourth ventricle and intraparen- in a patient with catastrophic traumatic chymal haemorrhage in both cerebellar pedun- brain injury. cles and pons. Laboratory tests including A patient is described with epidural serum alcohol concentration and urinary toxi- haematoma with normal breathing and cology screen were unremarkable. He was blood pressure and a retained coughing taken to surgery as an emergency for left crani- reflex brought on only by catheter suc- otomy and removal of epidural haematoma. tioning of the carina. Multiple contusions in the thalami and pons were found but POSTOPERATIVE COURSE the medulla oblongata was spared at After evacuation of the epidural haematoma he necropsy. remained comatose. Repeat brain CT showed a In conclusion, medulla oblongata function new large epidural haematoma in the posterior may persist despite rostrocaudal deterio- fossa with a stellate haematoma in the pons and ration. This comatose state (“medulla newly imaged contusions in both thalami. man”) closely mimics brain death. Neurological examination by one of the ( 2001;70:127–129) J Neurol Neurosurg Psychiatry attending physicians showed lack of conscious- Keywords: brain death; head injury; apnoea test; ness, virtually absent brain stem reflexes (with outcome specific attention to vertical eye movement and blinking), and no motor response to pain. A cough response was momentarily noted by one Department of Any neurological catastrophe may result in of the attending nurses but no recognisible Neurology, Neurologic- brain death and its transition is typically deter- response was seen with movement of the Neurosurgical mined by clinical neurological examination endotracheal tube. A brief episode of hypoten- http://jnnp.bmj.com/ Intensive Care Unit, alone.1 In many countries of the world, sion with a systolic blood pressure of 80 mm Saint Marys Hospital, confirmatory tests are optional in adults but Hg was noted. 1216 Second Street SW remain obligatory in children and the new- Phenylephrine was administered to ensure 55905 Rochester, 2 Minnisota, USA born. Therefore, clinical examination should adequate perfusion. No diabetes insipidus was E F M Wijdicks be unequivocal and precise. It should include seen. An apnoea test was performed. Within testing of respiratory drive after maximal minutes after disconnection a spontaneous Department of stimulation of the respiratory centres with regular respiratory eVort with tidal volumes Neurosurgery hypercarbia using apnoeic oxygenation tech- between 300–500 ml was recorded at a Pco of on October 2, 2021 by guest. Protected copyright. J L D Atkinson 2 niques. Only a few cases have been described in 34 mm Hg. Re-examination of the patient (by Department of which spontaneous breathing occurs during EFMW) showed absent brain stem reflexes but Anatomic Pathology apnoea testing.3 a notable discrepancy between upper and lower and Neuropathology, We report on a patient with an isolated, tracheal stimulation and response. Up and Mayo Clinic and barely detectable, cough response and sponta- down movement of the endotracheal tube pro- Foundation, 200 First neous breathing of several days’ duration until duced no response. Deep catheter suctioning Street SW, Rochester, MN 55905, Minnesota, withdrawal of support. This comatose state of the carina or mainstem bronchus elicited a USA closely mimics brain death. reproducible, but faint, cough response. This H Okazaki clinical condition persisted for 48 hours. Two Case description additional apnoea tests with roughly 12 hour Correspondence to: This patient was extracted from a car after a intervals produced similar results. The family Professor EFMWijdicks, Department of Neurology, motor vehicle accident. During transport to the decided to withdraw support and the patient Mayo Clinic, 200 First Street hospital he remained unconscious, possibly was placed on a T piece with 4 l oxygen. For an SW, Rochester, Minnesota had an apnoeic episode, developed bradycar- additional 8 hours the patient had normal res- 55905, 507–284–2511, USA [email protected] dia, and was intubated. On arrival, Glasgow piratory drive but was intermittently tachyp- coma sum score was 3, the left pupil was noeic with rates varying from 20–30/minute. Received 3 February 2000 dilated (diameter of 8 mm), fixed to light, the Oxygenation measured by pulse oxymetry and in revised form 20 May 2000 right pupil was normal size (diameter of 4 mm) remained normal. Blood pressures stabilised at Accepted 27 June 2000 with a normal light response, but oculocephalic 90–100 mm Hg systolic pressure without the www.jnnp.com 128 Wijdicks, Atkinson, Okazaki J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.70.1.127 on 1 January 2001. Downloaded from Serial macroscopical brain slices show multiple trauma induced haemorrhagic lesions in the cerebellum, thalamus, and pons but with sparing of the medulla oblongata. use of pharmacological support. Respiratory showed no intrinsic lesions save for minimal arrest within minutes occurred after extubation perivascular haemorrhages along the fourth after withdrawal of support. ventricular surface. Additionally, there was herniation of the left NEUROPATHOLOGY lateral hemispheric brain tissue through the At necropsy, there were multiple closed skull large craniotomy defect, up to 1.5 cm in height, fractures involving the bilateral parieto- accompanied by evidence of recent venous- occipital sutures, the occipital bone, the type infarction, most notable at the marginal petrous portion of the temporal bones, and the zones of the herniated tissue which had been roof of the right orbit. Superficial contusions compressed against the bony edge of the crani- were noted in the ventral surfaces of the frontal otomy defect. There were no residual epidural lobes; the anterior, ventral, and lateral aspects or subdural haemorrhages in this area. http://jnnp.bmj.com/ of the temporal lobes; splenium; and the However, there was a large (16×9×2 cm) ventral surfaces of the cerebellar hemispheres. fresh epidural haemorrhage making a mild The lesions central to the clinical presenta- indentation of both the occipital and posterior, tion of this case were found in the rostral and particularly lateral temporal, aspects of the cer- middle brain stem constituting deep contusive ebrum. lesions (figure). There was mild shift of the cerebral midline Most rostrally, haemorrhages were found in structures from left to right. A mild bowing of the hypothalami and paramedian thalami, the paramedian cerebral cortex above the cor- on October 2, 2021 by guest. Protected copyright. bilaterally and in the left lateral thalamus and pus callosum was seen and limited bilateral internal capsule. In the midbrain, smaller uncal herniation without any significant mesial haemorrhages were dispersed across the cross temporal lobe herniation, or rostral or caudal sections, whereas at the upper and midpontine compression of the midbrain or upper pons. levels, they coalesced to form a large central Histological examination showed no well confluent area measuring 3×3cmatits developed areas of axonal disruption except in maximal dimension. There was a limited the vicinity of contusion or postoperative areas rupture into the fourth ventricle. In the lower (APP and neurofilament immunostains). Eosi- pons, small haemorrhages were largely limited nophilic degeneration among scattered neocor- to the midline area. tical and hippocampal neurons was seen. Also present were haemorrhages in the inte- rior of the dorsal vermis, the white matter and Discussion dentate nuclei of both cerebellar hemispheres, Our case is unique because we document the separate from the mild cortical lesions de- presence of retained coughing with a vigorous scribed previously in the ventral surface of the stimulus, normal breathing drive and oxygena- cerebellum. tion, and normal blood pressure despite the The medulla showed only a mild extrinsic loss of other brainstem reflexes. Typically, compression of its posterolateral aspects at its medullary destruction loss is a final event in middle level by a mild tonsillar herniation but rostrocaudal herniation syndromes; however, www.jnnp.com Isolated medulla oblongata function after severe traumatic brain injury 129 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.70.1.127 on 1 January 2001. Downloaded from its function loss may take several additional patient rather than lead to the usual expected hours to complete. In our case, progression demise of haemodynamic systems and cardiac from the initial impact did not involve medul- arrest. lary structures. Three categories of pitfalls in the diagnosis A few cases of spontaneous breathing during of brain death have been identified by Pallis the apnoea test in patients who have fulfilled all and Harley.6 These are failure to meet precon- other clinical criteria of brain death have been ditions and exclusions, diYculty with interpret- published. Notably, Ropper et al reported four ation of signs, and failure
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