Electroencephalography (EEG) is useful as an objective electrophysiologic assay of cortical function in patients who do not respond to normal sensory stimuli. A typical waking EEG is dominated anteriorly by low-voltage beta activity (faster than 13 Hz). During periods of quiet wakefulness, the EEG may slow into the alpha range (8 to 13 Hz) and the wave activity may be more rhythmic and symmetric. As the patient becomes more drowsy, higher voltage theta rhythms (4 to 7 Hz) become dominant;
delta activity (1 to 3 Hz) predominates in
patients who are deeply asleep or comatose.
The EEG provides a rough but fairly accurate estimate of the degree to which a patient who is unresponsive may be simply uncooperative.
On the other hand, occasional patients with coma due to brainstem injury show an alpha EEG pattern. The alpha activity in such patients is usually more regular and less variable than in an awake patient, and it is not inhibited by opening the eyes.163 It may be possible to drive the EEG by photic stimulation in alpha coma. Certain types of metabolic encephalopathy may also have characteristic EEG changes. For example,triphasic waves are often seen in patients with hepatic encephalopathy, but can be seen in other metabolic disorders that cause coma.163,164
The EEG is most helpful in diagnosing impairment of consciousness due to nonconvulsive status epilepticus.165 Such patients may lack the usual behavioral signs of complex partial seizures, such as lip smacking or blinking, and may present as merely confused, drowsy, or even stuporous or comatose. Some patients may demonstrate twitching movements of the eyelids or extremities, but others give no external sign of epileptic activity. In one series, 8% of comatose patients were found to be suffering from nonconvulsive status epilepticus.166 When the EEG shows continuous epileptic activity, the diagnosis is easy and anticonvulsants are required. However, nonconvulsive status epilepticus may occur in patients without characteristic EEG changes,167 probably because the seizure activity is mainly in areas such as the medial temporal lobes that are not sampled by the surface electrodes.
Accordingly, if one suspects that the patient’s loss of consciousness is a result of nonconvulsive status epilepticus, it is probably wise to administer a short-acting benzodiazepine and observe the patient’s response. If the patient improves, antiepileptic drugs should be administered.Unfortunately, some patients with a clinical and electroencephalographic diagnosis of nonconvulsive status epilepticus do not respond to anticonvulsant drugs, because the underlying process causing the seizure activity is too severe to be suppressed by routine doses of drugs. Such patients are sometimes treated by large intravenous doses of
gamma-aminobutyric acid agonist drugs, such as barbiturates or propofol, which at sufficiently high dosage can suppress all brain activity.
However, unless the underlying brain process can be reversed, the prognosis of patients with nonconvulsive status epilepticus who do not awaken after anticonvulsant treatment is poor168 (see also Seizures in Chapter 5). Evoked potentials may also be used to test the integrity of brainstem and forebrain pathways in comatose patients. Although they do not provide reliable information on the location of a lesion in the brainstem, both auditoryand somatosensory-evoked potentials, and cortical event-related potentials, can provide information on the prognosis of patients in coma.169 This use will be discussed in greater detail in Chapter 8.
REFERENCES
1. Dunn C, Held JL, Spitz J, et al. Coma blisters:
report and review. Cutis 45 (6), 423–426, 1990.
2. Teasdale G, Jennett B. Assessment and prognosis of coma after head injury. Acta Neurochir (Wien) 34 (1–4), 45–55, 1976.
3. Gill MR, Reiley DG, Green SM. Interrater reliability of Glasgow Coma Scale scores in the emergency department. Ann Emerg Med 43, 215–223, 2004.
4. McNarry AF, Goldhill DR. Simple bedside assessment of level of consciousness: comparison of two simple assessment scales with the Glasgow Coma scale. Anaesthesia 59, 34–37, 2004.
5. Servadei F. Coma scales. Lancet 367 (9510), 548–
549, 2006.
6. Ropper AH, O’Rourke D, Kennedy SK. Head position, intracranial pressure, and compliance.
Neurology 32 (11), 1288–1291, 1982.
7. Saper CB, Loewy AD, Swanson LW, et al. Direct hypothalamo-autonomic connections. Brain Res 117 (2), 305–312, 1976.
8. Saper CB. Central autonomic system. In Paxinos G.
ed. The Rat Nervous System. Elsevier Academic Press, San Diego, pp 761–796, 2004.
9. Rossetti AO, Reichhart MD Bogousslavsky J. Central Horner’s syndrome with contralateral ataxic hemiparesis: a diencephalic alternate syndrome.
Neurology 61 (3), 334–338, 2003.
10. Reeves AG, Posner JB. The ciliospinal response in man. Neurology 19, 1145–1152, 1969.
11. Vassend O, Knardahl S. Cardiovascular responsiveness to brief cognitive challenges and pain sensitivity in women. Eur J Pain 8 (4), 315–324, 2004.
12. Zidan AH, Girvin JP. Effect on the Cushing response of different rates of expansion of a supratentorial mass. J Neurosurg 49 (1), 61–70, 1978.
13. Kawahara E, Ikeda S, Miyahara Y, et al. Role of autonomic nervous dysfunction in
electrocardio-graphic abnormalities and cardiac injury in patients with acute subarachnoid hemorrhage. Circ J 67 (9), 753– 756, 2003.
14. Lorsheyd A, Simmers TA Robles De Medina EO.
The relationship between electrocardiographic abnormalities and location of the intracranial aneurysm in subarachnoid hemorrhage. Pacing Clin Electrophysiol 26 (8), 1722–1728, 2003.
15. McLaughlin N, Bojanowski MW, Girard F, et al.
Pulmonary edema and cardiac dysfunction following subarachnoid hemorrhage. Can J Neurol Sci 32 (2), 178–185, 2005.
16. Ferrante L, Artico M, Nardacci B, Fraioli B, Cosentino F, Fortuna A. Glossopharyngeal neuralgia with cardiac syncope. Neurosurgery 36, 58–63, 1995.
17. Cole CR, Zuckerman J Levine BD. Carotid sinus
‘‘irritability’’ rather than hypersensitivity: a new name for an old syndrome? Clin Auton Res 11(2), 109– 113, 2001.
18. Paulson OB, Strandgaard S Edvinsson L. Cerebral autoregulation. Cerebrovasc Brain Metab Rev 2(2), 161–192, 1990.
19. Strandgaard S, Paulson OB. Regulation of cerebral blood flow in health and disease. J Cardiovasc Pharmacol 19 (Suppl 6), S89–S93, 1992.
20. Wahl M, Schilling L. Regulation of cerebral blood flow—a brief review. Acta Neurochir Suppl (Wien) 59, 3–10, 1993.
21. Schondorf R, Benoit J, Stein R. Cerebral autoregulation in orthostatic intolerance. Ann N Y Acad Sci 940, 514–526, 2001.
22. Sato A, Sato Y, Uchida S. Regulation of cerebral cortical blood flow by the basal forebrain cholinergic fibers and aging. Auton Neurosci 96 (1), 13–19, 2002.
23. Bieger D, Hopkins DA. Viscerotopic representation of the upper alimentary tract in the medulla oblongata in the rat: the nucleus ambiguus. J Comp Neurol 262 (4), 546–562, 1987.
24. Ross CA, Ruggiero DA, Park DH, et al. Tonic vasomotor control by the rostral ventrolateral medulla: effect of electrical or chemical stimulation of the area containing C1 adrenaline neurons on arterial pressure, heart rate, and plasma catecholamines and vasopressin. J Neurosci 4(2), 474–494, 1984.
25. Panneton WM, Loewy AD. Projections of the carotid sinus nerve to the nucleus of the solitary tract in the cat. Brain Res 191 (1), 239–244, 1980.
26. Ciriello J. Brainstem projections of aortic baroreceptor afferent fibers in the rat. Neurosci Lett 36 (1), 37–42, 1983.
27. Ross CA, Ruggiero DA, Reis DJ. Projections from the nucleus tractus solitarii to the rostral ventrolateral medulla. J Comp Neurol 242 (4), 511–534, 1985.
28. Blessing WW, Reis DJ. Inhibitory cardiovascular function of neurons in the caudal ventrolateral medulla of the rabbit: relationship to the area containing A1 noradrenergic cells. Brain Res 253 (1–
2), 161– 171, 1982.
29. Smith JC, Ellenberger HH, Ballanyi K, et al.
PreBotzinger complex: a brainstem region that may
Examination of the Comatose Patient 97 generate respiratory rhythm in mammals. Science
254 (5032), 726–729, 1991.
30. Gray PA, Janczewski WA, Mellen N, et al. Normal breathing requires preBotzinger complex neurokinin-1 receptor-expressing neurons. Nat Neurosci 4, 927–
930, 2001.
31. Wallach JH, Loewy AD. Projections of the aortic nerve to the nucleus tractus solitarius in the rabbit.
Brain Res 188 (1), 247–251, 1980.
32. Torrealba F, Claps A. The carotid sinus connections:
a WGA-HRP study in the cat. Brain Res 455 (1),
34. Feldman JL, Ellenberger HH. Central coordination of respiratory and cardiovascular control in mammals.
Annu Rev Physiol 50, 593–606, 1988.
35. Weston MC, Stornetta RL, Guyenet PG.
Glutamatergic neuronal projections from the marginal layer of the rostral ventral medulla to the respiratory centers in rats. J Comp Neurol 473 (1), 73–85, 2004.
36. Richerson GB. Serotonergic neurons as carbon dioxide sensors that maintain pH homeostasis. Nat Rev Neurosci 5(6), 449–461, 2004.
37. Chamberlin NL, Saper CB. Topographic organization of respiratory responses to glutamate microstimulation of the parabrachial nucleus in the rat. J Neurosci 14 (11 Pt 1), 6500–6510, 1994.
38. Chamberlin NL, Saper CB. A brainstem network mediating apneic reflexes in the rat. J Neurosci 18 (15), 6048–6056, 1998.
39. Meah MS, Gardner WN. Post-hyperventilation apnoea in conscious humans. J Physiol 477 (Pt 3), 527– 538, 1994.
40. Jennett S, Ashbridge K, North JB. Post-hyperventilation apnoea in patients with brain damage. J Neurol Neurosurg Psychiatry 37 (3), 288–
296, 1974.
41. Cherniack NS, Longobardo G, Evangelista CJ.
Causes of Cheyne-Stokes respiration. Neurocrit Care 3(3), 271–279, 2005.
42. Lange RL, Hecht HH. The mechanism of CheyneStokes respiration. J Clin Invest 41, 42–52, 1962.
43. Murdock DK, Lawless CE, Loeb HS, et al. The effect of heart transplantation on Cheyne-Stokes respiration associated with congestive heart failure. J Heart Transplant 5(4), 336–337, 1986.
44. Hudgel DW, Devadatta P, Quadri M, et al.
Mechanism of sleep-induced periodic breathing in convalescing stroke patients and healthy elderly subjects. Chest 104 (5), 1503–1510, 1993.
45. Rubin AE, Gottlieb SH, Gold AR, et al. Elimination of central sleep apnoea by mitral valvuloplasty: the role of feedback delay in periodic breathing. Thorax 59 (2), 174–176, 2004.
46. Vespa PM, Bleck TP. Neurogenic pulmonary edema and other mechanisms of impaired oxygenation after aneurysmal subarachnoid hemorrhage. Neurocrit Care 1(2), 157–170, 2004.
47. Simon RP. Neurogenic pulmonary edema. Neurol Clin 11(2), 309–323, 1993.
48. Tarulli AW, Lim C, Bui JD, et al. Central neurogenic hyperventilation: a case report and discussion of pathophysiology. Arch Neurol 62 (10), 1632–1634, 2005.
49. Shams PN, Waldman A, Plant GT. B cell lymphoma of the brain stem masquerading as myasthenia. J Neurol Neurosurg Psychiatry 72, 271–273, 2002.
50. Rodriguez M, Baele PL, Marsh HM, et al. Central neurogenic hyperventilation in an awake patient with brainstem astrocytoma. Ann Neurol 11, 625–628, 1982.
51. Siderowf AD, Balcer LJ, Kenyon LC, et al. Central neurogenic hyperventilation in an awake patient with a pontine glioma. Neurology 46, 1160–1162, 1996.
52. Hilaire G, Pasaro R. Genesis and control of the respiratory rhythm in adult mammals. News Physiol Sci 18, 23–28, 2003.
53. El Khatib MF, Kiwan RA, Jamaleddine GW.
Buspirone treatment for apneustic breathing in brain stem infarct. Respir Care 48, 956–958, 2003.
54. Bassetti C, Aldrich MS, Quint D. Sleep-disordered breathing in patients with acute supra- and infratentorial strokes. A prospective study of 39 patients. Stroke 28, 1765–1772, 1997.
55. Pang KP, Terris DJ. Screening for obstructive sleep apnea: an evidence-based analysis. Am J Otolaryngol 27 (2), 112–118, 2006.
56. Iber C. Sleep-related breathing disorders. Neurol Clin 23(4), 1045–1057, 2005.
57. Schlaefke ME, Kille JF, Loeschcke HH. Elimination of central chemosensitivity by coagulation of a bilateral area on the ventral medullary surface in awake cats. Pflugers Arch 378 (3), 231–241, 1979.
58. Fodstad H. Pacing of the diaphragm to control breathing in patients with paralysis of central nervous system origin. Stereotact Funct Neurosurg 53 (4), 209–222, 1989.
59. Bogousslavsky J, Khurana R, Deruaz JP, et al.
Respiratory failure and unilateral caudal brainstem infarction. Ann Neurol 28 (5), 668–673, 1990.
60. Auer RN, Rowlands CG, Perry SF, et al. Multiple sclerosis with medullary plaques and fatal sleep apnea (Ondine’s curse). Clin Neuropathol 15 (2), 101– 105, 1996.
61. Manconi M, Mondini S, Fabiani A, et al. Anterior spinal artery syndrome complicated by the Ondine curse. Arch Neurol 60 (12), 1787–1790, 2003.
62. Polatty RC, Cooper KR. Respiratory failure after percutaneous cordotomy. South Med J 79 (7), 897–
899, 1986.
63. Amiel J, Laudier B, ttie-Bitach T, et al. Polyalanine expansion and frameshift mutations of the pairedlike homeobox gene PHOX2B in congenital central hypoventilation syndrome. Nat Genet 33 (4), 459– respiratory and locomotor rhythms onto single neurons of the lateral reticular nucleus. Exp Brain Res 113 (2), 230–242, 1997.
66. Daquin G, Micallef J, Blin O. Yawning. Sleep Med Rev 5(4), 299–312, 2001.
67. Argiolas A, Melis MR. The neuropharmacology of yawning. Eur J Pharmacol 343 (1), 1–16, 1998.
68. Launois S, Bizec JL, Whitelaw WA, et al. Hiccup in adults: an overview. Eur Respir J 6, 563–575, 1993.
69. Straus C, Vasilakos K, Wilson RJ, et al. A phylogenetic hypothesis for the origin of hiccough.
Bioessays 25, 182–188, 2003.
70. Cersosimo RJ, Brophy MT. Hiccups with high dose dexamethasone administration—a case report. Cancer 82, 412–414, 1998.
71. LeWitt PA, Barton NW, Posner JB. Hiccup with dexamethasone therapy. Letter to the editor. Ann Neurol 12, 405–406, 1982.
72. Souadjian JV, Cain JC. Intractable hiccup. Etiologic factors in 220 cases. Postgrad Med 43, 72–77, 1968.
73. Walker P, Watanabe S, Bruera E. Baclofen, a vagal afferents may mediate both retching and gastric adaptive relaxation in dogs. Auton Neurosci 93 (1–2), 21–30, 2001.
76. Balaban CD. Vestibular autonomic regulation (including motion sickness and the mechanism of vomiting). Curr Opin Neurol 12 (1), 29–33, 1999.
77. Hornby PJ. Central neurocircuitry associated with emesis. Am J Med 111 (Suppl 8A), 106S–112S, 2001.
78. Yamamoto H, Kishi T, Lee CE, et al. Glucagon-like peptide-1-responsive catecholamine neurons in the area postrema link peripheral glucagon-like peptide1 with central autonomic control sites. J Neurosci 23(7), 2939–2946, 2003.
79. Chen CJ, Scheufele M, Sheth M, et al. Isolated relative afferent pupillary defect secondary to contralateral midbrain compression. Arch Neurol 61, 1451–1453, 2004.
80. Hornblass A. Pupillary dilatation in fractures of the floor of the orbit. Ophthalmic Surg 10(11), 44–46, 1979.
81. Antonio-Santos AA, Santo RN, Eggenberger ER.
Pharmacological testing of anisocoria. Expert Opin Pharmacother 6 (12), 2007–2013, 2005.
82. McLeod JG, Tuck RR. Disorders of the autonomic nervous system: part 2. Investigation and treatment.
Ann Neurol 21(6), 519–529, 1987.
83. Zhang YH, Lu J, Elmquist JK, et al.
Lipopolysaccharide activates specific populations of hypothalamic and brainstem neurons that project to the spinal cord. J Neurosci 20 (17), 6578–6586, 2000.
84. Llewellyn-Smith IJ, Martin CL, Marcus JN, et al.
Orexin-immunoreactive inputs to rat sympathetic preganglionic neurons. Neurosci Lett 351 (2), 115–
119, 2003.
85. Estabrooke IV, McCarthy MT, Ko E, et al. Fos expression in orexin neurons varies with behavioral state. J Neurosci 21(5), 1656–1662, 2001.
86. Loewy AD, Araujo JC, Kerr FW. Pupillodilator pathways in the brain stem of the cat: anatomical and
electrophysiological identification of a central autonomic pathway. Brain Res 60 (1), 65–91, 1973.
87. Burde RM, Loewy AD. Central origin of oculomotor parasympathetic neurons in the monkey. Brain Res melanopsin in nonvisual photoreception. J Neurosci 23(18), 7093–7106, 2003.
90. Buttner-Ennever JA, Cohen B, Horn AK, et al.
Pretectal projections to the oculomotor complex of the monkey and their role in eye movements. J Comp Neurol 366 (2), 348–359, 1996.
91. Jampel RS. Convergence, divergence, pupillary reactions and accommodation of the eyes from faradic stimulation of the macaque brain. J Comp Neurol 115, 371–399, 1960.
92. Kerr FW, Hallowell OW. Location of the pupillomotor and accommodation fibers in the oculomotor nerve: experimental observations on paralytic mydriasis. J Neurol Neurosurg Psychiatry 27, 473– 481, 1964.
93. Leigh RJ, Zee DS. The Neurology of Eye Movements, 4th ed. New York: Oxford University Press, 2006.
94. Hanson RA, Ghosh S, Gonzalez-Gomez I, et al.
Abducens length and vulnerability? Neurology 62 (1), 33–36, 2004.
95. Zee DS. Brain stem and cerebellar deficits in eye movement control. Trans Ophthalmol Soc U K 105 (Pt 5), 599–605, 1986.
96. Henn V. Pathophysiology of rapid eye movements in the horizontal, vertical and torsional directions.
Baillieres Clin Neurol 1(2), 373–391, 1992.
97. Sparks DL, Mays LE. Signal transformations required for the generation of saccadic eye movements. Annu Rev Neurosci 13, 309–336, 1990.
98. Lewis RF, Zee DS. Ocular motor disorders associated with cerebellar lesions: pathophysiology and topical localization. Rev Neurol (Paris) 149 (11), 665– 677, 1993.
99. Buettner UW, Zee DS. Vestibular testing in comatose patients. Arch Neurol 46 (5), 561–563, 1989.
100. Helmchen C, Rambold H, Kempermann U, et al.
Localizing value of torsional nystagmus in small midbrain lesions. Neurology 59 (12), 1956–1964, 2002.
101. Krauzlis RJ. Recasting the smooth pursuit eye movement system. J Neurophysiol 91 (2), 591–603, 2004.
102. Leichnetz GR. An anterogradely-labeled prefrontal cortico-oculomotor pathway in the monkey demonstrated with HRP gel and TMB neurohistochemistry. Brain Res 198 (2), 440–445, 1980.
103. Barton JJ, Simpson T, Kiriakopoulos E, et al.
Functional MRI of lateral occipitotemporal cortex during pursuit and motion perception. Ann Neurol 40 (3), 387–398, 1996.
Examination of the Comatose Patient 99
106. Caplan LR. Ptosis. J Neurol Neurosurg Psychiatry 37 (1), 1–7, 1974.
107. Hackley SA, Johnson LN. Distinct early and late subcomponents of the photic blink reflex: response characteristics in patients with retrogeniculate lesions. Psychophysiology 33, 239–251, 1996.
108. Liu GT, Ronthal M. Reflex blink to visual threat. J Clin Neuroophthalmol 12, 47–56, 1992.
109. Wijdicks EF, Bamlet WR, Maramattom BV, et al.
Validation of a new coma scale: the FOUR score.
Ann Neurol 58 (4), 585–593, 2005.
110. Pullicino PM, Jacobs L, McCall WD Jr, et al.
Spontaneous palpebromandibular synkinesia: a localizing clinical sign. Ann Neurol 35 (2), 222–228, 1994.
111. Roberts TA, Jenkyn LR, Reeves AG. On the notion of doll’s eyes. Arch Neurol 41, 1242–1243, 1984.
112. Schubert MC, Das V, Tusa RJ, et al. Cervico-ocular reflex in normal subjects and patients with unilateral vestibular hypofunction. Otol Neurotol 25 (1), 65–
71, 2004.
113. Schlosser HG, Unterberg A, Clarke A. Using videooculography for galvanic evoked vestibulo-ocular monitoring in comatose patients. J Neurosci Methods 145 (1–2), 127–131, 2005.
114. Brandt TH, Dieterich M. Different types of skew deviation. J Neurol Neurosurg Psychiatry 54, 549–
550, 1991.
115. Fisher CM. Some neuro-ophthalmological observations. J Neurol Neurosurg Psychiatry 30 (5), 383– 392, 1967.
116. Chung CS, Caplan LR, Yamamoto Y, et al.
Striatocapsular haemorrhage. Brain 123 (Pt 9), 1850–
1862, 2000.
117. Baloh RW, Furman JM, Yee RD. Dorsal midbrain syndrome: clinical and oculographic findings.
Neurology 35 (1), 54–60, 1985.
118. Choi KD, Jung DS, Kim JS. Specificity of ‘‘peering at the tip of the nose’’ for a diagnosis of thalamic hemorrhage. Arch Neurol 61, 417–422, 2004.
119. Litvan I, Jankovic J, Goetz CG, et al. Accuracy of the clinical diagnosis of postencephalitic parkinsonism: a clinicopathologic study. Eur J Neurol 5 (5), 451–457, 1998.
120. Jhee SS, Zarotsky V, Mohaupt SM, et al. Delayed onset of oculogyric crisis and torticollis with intramuscular haloperidol. Ann Pharmacother 37 (10), 1434–1437, 2003.
121. Pannullo SC, Reich JB, Krol G, et al. MRI changes in intracranial hypotension. Neurology 43, 919–926, 1993. cases. Arch Neurol 32 (3), 185–190, 1975.
125. Smith JL, David NJ, Klintworth G. Skew deviation.
Neurology 14, 96–105, 1964.
126. Johkura K, Komiyama A, Tobita M, et al. Saccadic ping-pong gaze. J Neuroophthalmol 18, 43–46, 1998.
127. Daroff RB, Hoyt WF. Supranuclear disorders of ocular control systems in man: clinical, anatomical and physiological correlations. In: Bach-y-Rita P, Collins CC, Hyde JE, eds. The Control of Eye Movements. New York: Academic Press, pp 175–
235, 1971.
128. Ochs AL, Stark L, Hoyt WF, et al. Opposed adducting saccades in convergence-retraction nystagmus: a patient with sylvian aqueduct syndrome. Brain 102 (3), 497–508, 1979.
129. Fischer CM. Ocular bobbing. Arch Neurol 11, 543–
546, 1964.
130. Rosenberg ML. Spontaneous vertical eye movements in coma. Ann Neurol 20 (5), 635–637, 1986.
131. Herishanu YO, Abarbanel JM, Frisher S, et al.
Spontaneous vertical eye movements associated with pontine lesions. Isr J Med Sci 27 (6), 320–324, 1991.
132. Lourie H. Seesaw nystagmus. Case report elucidating the mechanism. Arch Neurol 9, 531–533, 1963.
133. Sano K, Sekino H, Tsukamoto Y, et al. Stimulation and destruction of the region of the interstitial nucleus in cases of torticollis and see-saw nystagmus.
Confin Neurol 34 (5), 331–338, 1972.
134. Keane JR. Intermittent see-saw eye movements.
Report of a patient in coma after hyperextension head injury. Arch Neurol 35 (3), 173–174, 1978.
135. Schott JM, Rossor MN. The grasp and other primitive reflexes. J Neurol Neurosurg Psychiatry 74 (5), 558–560, 2003.
136. Jacobs L, Gossman MD. Three primitive reflexes in normal adults. Neurology 30 (2), 184–188, 1980.
137. De RE, Barbieri C. The incidence of the grasp reflex following hemispheric lesion and its relation to frontal damage. Brain 115 (Pt 1), 293–313, 1992.
138. Greenberg DA, Simon RP. Flexor and extensor postures in sedative drug-induced coma. Neurology 32 (4), 448–451, 1982.
139. Jennett B, Teasdale G. Aspects of coma after severe head injury. Lancet 1(8017), 878–881, 1977.
140. Sherrington CS. Cataleptoid reflexes in the monkey.
Proc Royal Soc Lond 60, 411–414, 1897.
141. Kirk MM, Hoogwerf BJ, Stoller JK. Reversible decerebrate posturing after profound and prolonged hypoglycemia. Cleve Clin J Med 58 (4), 361–363, fulminant hepatic failure. Liver Transpl 9 (12), 1244–
1252, 2003.
144. Kosaka Y, Tanaka K, Sawa H, et al. Acid-base disturbance in patients with fulminant hepatic failure.
Gastroenterol Jpn 14(1), 24–30, 1979.
145. Krapf R, Caduff P, Wagdi P, et al. Plasma potassium response to acute respiratory alkalosis. Kidney Int 47 (1), 217–224, 1995.
146. Spector RH, Davidoff RA, Schwartzman RJ.
Phenytoin-induced ophthalmoplegia. Neurology 26 (11), 1031–1034, 1976.
147. Pulst SM, Lombroso CT. External ophthalmoplegia, alpha and spindle coma in imipramine overdose: case report and review of the literature. Ann Neurol 14(5), 587–590, 1983.
148. Odaka M, Yuki N, Yamada M, et al. Bickerstaff’s brainstem encephalitis: clinical features of 62 cases and a subgroup associated with Guillain-Barre syndrome. Brain 126 (Pt 10), 2279–2290, 2003.
149. Ragosta K. Miller Fisher syndrome, a brainstem encephalitis, mimics brain death. Clin Pediatr (Phila) 32 (11), 685–687, 1993.
150. Dhiravibulya K, Ouvrier R, Johnston I, et al. Benign intracranial hypertension in childhood: a review of 23 patients. J Paediatr Child Health 27 (5), 304–307, 1991.
151. Thomke F, Mika-Gruttner A, Visbeck A, et al. The risk of abducens palsy after diagnostic lumbar puncture. Neurology 54 (3), 768–769, 2000.
152. Speer C, Pearlman J, Phillips PH, et al. Fourth cranial nerve palsy in pediatric patients with pseudotumor cerebri. Am J Ophthalmol 127 (2), 236–237, 1999.
153. Malouf R, Brust JC. Hypoglycemia: causes, neurological manifestations, and outcome. Ann Neurol 17(5), 421–430, 1985.
154. Vaughan CJ, Delanty N. Hypertensive emergencies.
Lancet 356 (9227), 411–417, 2000.
155. Mitchell P, Wilkinson ID, Hoggard N, et al.
Detection of subarachnoid haemorrhage with magnetic resonance imaging. J Neurol Neurosurg Psychiatry 70, 205–211, 2001.
156. Lin A, Ross BD, Harris K, et al. Efficacy of proton magnetic resonance spectroscopy in neurological diagnosis and neurotherapeutic decision making.
NeuroRx 2(2), 197–214, 2005.
157. Guillevin R, Vallee JN, Demeret S, et al. Cerebral fat embolism: Usefulness of magnetic resonance spectroscopy. Ann Neurol 57, 434–439, 2005.
158. Schoning M, Scheel P, Holzer M, et al. Volume measurement of cerebral blood flow: assessment of cerebral circulatory arrest. Transplantation 80 (3), 326–331, 2005.
159. Dominguez-Roldan JM, Garcia-Alfaro C, JimenezGonzalez PI, et al. Brain death due to supratentorial masses: diagnosis using transcranial Doppler sonography. Transplant Proc 36 (10), 2898–
2900, 2004.
160. Wojner-Alexandrov AW, Alexandrov AV, Rodriguez D, et al. Houston paramedic and emergency stroke treatment and outcomes study (HoPSTO). Stroke 36 (7), 1512–1518, 2005.
161. Panerai RB, Kerins V, Fan L, et al. Association between dynamic cerebral autoregulation and mortality in severe head injury. Br J Neurosurg 18 (5), 471–479, 2004.
162. Droste DW, Metz RJ. Clinical utility of echocontrast agents in neurosonology. Neurol Res 26 (7), 754–
759, 2004.
163. Brenner RP. The interpretation of the EEG in stupor and coma. Neurologist 11(5), 271–284, 2005.
164. Kaplan PW. Assessing the outcomes in patients with nonconvulsive status epilepticus: nonconvulsive status epilepticus is underdiagnosed, potentially overtreated, and confounded by comorbidity. J Clin Neurophysiol 16 (4), 341–352, discussion 353, 1999.
165. Brenner RP. Is it status? Epilepsia 43 (Suppl 3), 103–
165. Brenner RP. Is it status? Epilepsia 43 (Suppl 3), 103–