Background: Multiple System Atrophy (MSA) is a progressive neuropathological disease characterized by autonomic instability plus Parkinsonian syndrome or ataxia.
Case: A 69-year-old male with history of MSA presented to our institution after a mechanical fall. On examination, patient was responsive but lethargic. His motor strength was 4/5 in right upper and 1/5 in right lower extremities. Initial CT scan revealed a 1.8 cm left subdural hematoma with 13 mm midline shift. An urgent craniotomy was performed for hematoma evacuation. The procedure was uneventful both from anesthesia and neurosurgical perspectives. The brain was noted to be "relaxed" prior to replacement of the bone flap and closure. Upon emergence from anesthesia, the patient remained unresponsive with an atypical respiratory pattern. Neurosurgery was notified and a stat head CT was obtained. The patient remained intubated and vital signs remained within target range during anesthesia transport. CT imaging revealed profound diffuse cerebral edema with loss of gray-white differentiation. Repeat physical exam revealed nonreactive, dilated pupils. A "brain code" was called, and the patient was transported directly back to the operating room for emergent decompressive hemi-craniectomy, while hyperosmolar therapy was administered. Upon opening of the dura, rapid, profound herniation of brain occurred in a manner incompatible with neurologic recovery. The scalp was rapidly approximated with staples, and the patient was transferred to the ICU. Shortly thereafter, the patient became hypotensive and required neuro-endocrine stabilization. The patient was declared brain dead the following morning.
Discussion: MSA is a progressive neuropathological disease that is a clinical diagnosis of exclusion based upon findings of autonomic instability along with Parkinsonian syndrome or ataxia. There have been case reports of perioperative hemodynamic volatility, which was not observed in our patient. There is also some data suggesting that MSA patients may have impaired cerebral autoregulation. There are a few notable findings from this case: 1) the development of profound cerebral edema that involved the entire brain including the right (non-injured) hemisphere; 2) the short time period over which the cerebral edema developed; 3) the severity of edema that was completely refractory to aggressive medical and surgical management; 4) the absence of the typical cardiovascular response of profound intracranial hypertension. Rapidly progressive diffuse cerebral edema can result from global hypoxic brain injury, such as following cardiac arrest, although development usually occurs over 6 hours and its progression is usually slowed by medical therapy. Conversely, vasogenic edema can develop rapidly due to profound hyperemia, as seen following carotid endarterectomies or surgical treatments of large AVM's. In our case, the etiology of cerebral edema remains unclear, but it is likely that the underlying MSA and its effect on autonomic function played a significant role. In the future, we would consider the use of neurophysiologic monitoring (SSEP/EEG) during intracranial operations through emergence from anesthesia in MSA patients as a method to identify the rapid development of cerebral edema. To the best of our knowledge, this is the first documentation in literature to describe anesthesia considerations for neurological surgery with MSA.
