Spontaneous respiratory movements with clinical brain death

[Irreversible brain death-Part 2. Spinalization phenomena]

Spinal automatisms and reflexes, peripheral neurogenic and myogenic reactions are common in patients with irreversible brain death. They are therefore compatible and are even understood by experienced investigators as confirmation of irreversible brain death. This article provides an overview of the phenomenology of irreversible brain death and discusses it from a neuropathological perspective. Furthermore, irreversible brain death is described in order to distinguish it from pathological movements and motor reactions in comatose patients or patients with disturbed consciousness due to severe brain disorders.

Movements in brain death: a systematic review

Brain death is the irreversible lost of function of the brain including the brainstem. The presence of spontaneous or reflex movements constitutes a challenge for the neurological determination of death. We reviewed historical aspects and practical implications of the presence of spontaneous or reflex movements in individuals with brain death and postulated pathophysiological mechanisms. We identified and reviewed 131 articles on movements in individuals with confirmed diagnosis of brain death using Medline from January 1960 until December 2007, using 'brain death' or 'cerebral death' and 'movements' or 'spinal reflex' as search terms. There was no previous systematic review of the literature on this topic. Plantar withdrawal responses, muscle stretch reflexes, abdominal contractions, Lazarus's sign, respiratory-like movements, among others were described. For the most part, these movements have been considered to be spinal reflexes. These movements are present in as many as 40-50% of heart-beating cadavers. Although limited information is available on the determinants and pathophysiological mechanisms of spinal reflexes, clinicians and health care providers should be aware of them and that they do not preclude the diagnosis of brain death or organ transplantation.

Some questions about brain death: a case report

A 13-year-old girl had an anaphylactic cardiac arrest with 45 minutes of resuscitation. After rewarming on day 3, a first examination was compatible with brain death, including an apnea test. Shortly thereafter, a stimulus to the trapezius muscle above the clavicles resulted in bilateral lower-limb withdrawal. A subsequent examination by another intensivist found, during vestibulo-ocular testing, bilateral lower-limb withdrawal. A radionuclide cerebral blood-flow test indicated no intracranial flow, and a computed tomography scan indicated diffuse severe cerebral edema. After these tests, stimulus to the trapezius muscle resulted in bilateral lower-limb extensor posturing. The next day, on repeated examination, the patient no longer had any response to stimulus, and was declared brain dead. This case raised two questions. Why should an intermittent lower-limb withdrawal response to supraclavicular stimulus be a more critical brain function, precluding a diagnosis of brain death (indicating that the patient has not lost integrative unity of the organism), than all other clinical and radiological findings? Was the withdrawal response of spinal origin or brainstem origin? How one chooses to interpret the withdrawal of lower limbs elicited by supraclavicular stimulus directly determines whether the patient in this case was dead.

The undulating toe flexion sign in brain death

Brain-dead patients may exhibit gross spontaneous and reflex movements (e.g., Babinski sign, stereotypic flexion of one or more limbs, and Lazarus sign). We report three brain-dead patients who had unusual complex sequential movements of the toes. Undulating toe flexion was elicited by noxious stimuli to the lower extremities, and consisted of initial plantar flexion of the great toe, followed by sequential brief plantar flexion of the second, third, fourth, and fifth toes. The undulating toe flexion sign differs from previously described responses characterized by plantar flexion of the toes (e.g., Rosselimo's sign and the Mendel-Bechterew sign) in that it consists of complex patterned sequential movements of the digits rather than brief simultaneous flexion and/or fanning of the toes. Neurologists should be aware of this unusual finding, which should not preclude the diagnosis of brain death.