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Rett Syndrome: Review of Biological Abnormalities

Published online by Cambridge University Press:  02 March 2017

Henry G. Dunn*
Affiliation:
Division of Neurology, British Columbia's Children's Hospital, Vancouver, BC, Canada
Patrick M. MacLeod
Affiliation:
Division of Neurology, British Columbia's Children's Hospital, Vancouver, BC, Canada
*
Division of Neurology, British Columbia's Children's Hospital, 4480 Oak Street, Vancouver, BC, Canada V6H 3V4
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Abstract:

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The Rett syndrome (RS) is a peculiar, sporadic, atrophic disorder, almost entirely confined to females. After the first six months of life there is developmental slowing with reduced communication and head growth for about one year. This is followed by a rapid destructive stage with severe dementia and loss of hand skills (with frequent hand wringing), apraxia and ataxia, autistic features and irregular breathing with hyperventilation. Seizures often supervene. Subsequently there is some stabilization in a pseudo-stationary stage during the preschool to school years, associated with more emotional contact but also abnormalities of the autonomic and skeletal systems. After the age of 15-20 years, a late motor deterioration occurs with dystonia and frequent spasticity but seizures become milder. RS has generally been considered an X-linked disorder in which affected females represent a new mutation, with male lethality. Linkage studies suggested a critical region at Xq28. In 1999, mutations in the gene MECP2 encoding X-linked methyl cytosine-binding protein 2 (MeCP2) were found in a proportion of Rett girls. This protein can bind methylated DNA. Analyses are leading to much further investigation of mutants and their effects on genes. Neuropathological and electrophysiological studies of RS are described. Description of neurometabolic factors includes reduced levels of dopamine, serotonin, noradrenaline and choline acetyltransferase (ChAT) in brain, also estimation of nerve growth factors, endorphin, substance P, glutamate and other amino acids and their receptor levels. The results of neuroimaging are surveyed, including volumetric magnetic resonance imaging (MRI) and positron emission tomography (PET).

Résumé:

RÉSUMÉ:

Le syndrome de Rett (SR) est une maladie atrophique sporadique singulière qui touche presque exclusivement les filles. Après les premiers six mois de la vie, l'enfant présente un ralentissement du développement accompagné d'une diminution de la communication et de la croissance de la tête pendant à peu près un an, suivi d'une phase de destruction rapide avec démence sévère et perte de la dextérité manuelle (avec de fréquents épisodes de torsion des mains), de l'apraxie et de l'ataxie, des manifestations autistiques et une respiration irrégulière avec hyperventilation. Des crises convulsives s'ajoutent souvent au tableau. Par la suite, il y a une certaine stabilisation ou phase pseudo-stationnaire pendant la période préscolaire et scolaire, associée à plus de contacts émotifs mais aussi à des anomalies des systèmes autonome et squelettique. Après l'âge de 15 ou 20 ans, on observe une détérioration motrice accompagnée de dystonie et fréquemment de spasticité, et les crises convulsives s'atténuent. En général, on a considéré que le SR est une maladie liée à l'X où les filles atteintes sont porteuses d'une nouvelle mutation, une telle mutation étant léthale chez les garçons. Des études de liaison ont indiqué une région critique au niveau de Xq28. En 1999, des mutations dans le gène MECP2, le gène de la protéine de liaison de la méthyl cytosine2 lié au X (MECP2), ont été identifiées chez des filles porteuses du SR. Cette protéine peut lier l'ADN méthylé. Ces analyses ont mené à des investigations plus poussées des mutants et de leurs effets sur les gènes voisins. Des études neuropathologiques et électrophysiologiques du SR sont décrites. Parmi les facteurs neurométaboliques, on fait état de niveaux abaissés de dopamine, de sérotonine, d'adrénaline et de choline acétyltransférase (ChAT) dans le cerveau, et on rapporte également une évaluation des facteurs de croissance nerveux, des endorphines, de la substance P, du glutamate et d'autres acides aminés et des niveaux de leurs récepteurs. Les résultats de la neuroimagerie sont présentés, incluant la RMN volumétrique et le PET scan.

Type
Review Article
Copyright
Copyright © The Canadian Journal of Neurological 2001

References

REFERENCES

1. Rett, A. Über ein eigenartiges hirnatrophisches Syndrom bei Hyperammonàmie im Kindesalter. Wien Klin Wochenschr 1966; 116: 723726.Google Scholar
2. Ishikawa, A, Goto, T, Narasaki, M, et al. A new syndrome (?) of progressive psychomotor deterioration with peculiar stereotype movement and autistic tendency: a report of three cases. Brain Dev (Tokyo) 1978; Old Series No. 3:258 (Abstract in English).Google Scholar
3. Hagberg, B, Aicardi, J, Dias, K, Ramos, O. A progressive syndrome of autism, dementia, ataxia, and loss of purposeful hand use in girls: Rett’s syndrome: report of 35 cases. Ann Neurol 1983; 14: 471479.Google Scholar
4. Hagberg, B, Witt-Engerstròm, I. Rett syndrome: a suggested staging system for describing impairment profile with increasing age towards adolescence. Am J Med Genet 1986; 24: Suppl. 1: 4759.Google Scholar
5. Rett Syndrome Diagnostic Criteria Work Group. Diagnostic criteria for Rett syndrome. Ann Neurol 1988; 23: 425428.Google Scholar
6. Hagberg, BA, Skjeldal, OH. Rett variants: a suggested model for inclusion criteria. Pediatr Neurol 1994; 11: 511.Google Scholar
7. Zappella, M. The Rett girls with preserved speech. Brain Dev 1992; 14: 98101.Google Scholar
8. Haas, RH, Dixon, SD, Sartoris, DJ, Hennessy, MJ. Osteopenia in Rett syndrome. J Pediatr 1997; 131: 771774.Google Scholar
9. Leonard, H, Thomson, MR, Glasson, EJ, et al. A population-based approach to the investigation of osteopenia in Rett syndrome. Dev Med Child Neurol 1999; 41: 323328.Google Scholar
10. Leonard, H, Thomson, M, Glasson, EJ, et al. Metacarpophalangeal pattern profile and bone age in Rett syndrome: further radiological clues to the diagnosis. Am J Med Genet 1999; 83: 8895.3.0.CO;2-7>CrossRefGoogle ScholarPubMed
11. Motil, KJ, Schultz, RJ, Browning, K, et al. Oropharyngeal dysfunction and gastroesophageal dysmotility are present in girls and women with Rett syndrome. J Pediatr Gastroenterol Nutr 1999; 29: 3137.CrossRefGoogle ScholarPubMed
12. Morton, RE, Pinnington, L, Ellis, RE. Air swallowing in Rett syndrome. Dev Med Child Neurol 2000; 42: 271275.Google Scholar
13. Hagberg, B. Rett’s syndrome: prevalence and impact on progressive severe mental retardation in girls. Acta Paediatr Scand 1985; 74: 405408.CrossRefGoogle ScholarPubMed
14. Kerr, AM, Stephenson, JBP. Rett’s syndrome in the West of Scotland. Br Med J 1985; 291: 579582.Google Scholar
15. Witt-Engerstròm, I, Gillberg, C. Rett syndrome in Sweden. J Autism Dev Disord 1987; 17: 149150.CrossRefGoogle ScholarPubMed
16. Akesson, HO. Rett syndrome: the Swedish Genealogic Research Project. New data and present position. Eur Child Adolesc Psychiatry 1997; 6 (Suppl 1): 9698.Google Scholar
17. Akesson, HO, Hagberg, B, Wahlstrom, J. Rett syndrome, classical and atypical: genealogical support for common origin. J Med Genet 1996; 33: 764766.Google Scholar
18. Pini, G, Milan, M, Zappella, M. Rett syndrome in northern Tuscany: family tree studies. Clin Genet 1996; 50: 486490.Google Scholar
19. Hollody, K, Borvendeg, K, Kosztolanyi, G. Pedigree analysis of Hungarian Rett syndrome girls. Eur Child Adolesc Psychiatry 1997; 6 (Suppl 1): 99100.Google Scholar
20. Leonard, H, Bower, C, English, D. The prevalence and incidence of Rett syndrome in Australia. Eur Child Adolesc Psychiatry 1997; 6(Suppl 1): 810.Google Scholar
21. Skjeldal, OH, von Tetzchner, S, Aspelung, F, et al. Rett syndrome: geographic variation in prevalence in Norway. Brain Dev 1997; 19: 258261.Google Scholar
22. Witt-Engerstròm, I, Forslund, M. Mother and daughter with Rett syndrome. Dev Med Child Neurol 1992; 34: 10221023.Google Scholar
23. Leonard, H, Silverstein, J, Falk, R, et al. Exploring the male phenotype. World Congress on Rett Syndrome 2000, Abstract PO–3, p 34.Google Scholar
24. Vorsanova, SG, Demidova, IA, Ulas, VY, et al. Cytogenetic and molecular-cytogenetic studies of Rett syndrome (RTT). A retrospective analysis of Russian cohort of RTT patients. World Congress on Rett Syndrome 2000, PO–31:48.Google Scholar
25. Schanen, NC, Kurczynski, TW, Brunelle, D, et al. Neonatal encephalopathy in two boys in families with recurrent Rett syndrome. J Child Neurol 1998; 13: 229231.Google Scholar
26. Wan, M, Lee, SSJ, Zhang, X, et al. Rett syndrome and beyond: recurrent spontaneous and familial MECP2 mutations at CPG hotspots. Am J Hum Genet 1999; 65: 15201529.CrossRefGoogle ScholarPubMed
27. Zoghbi, HY, Percy, AK, Schultz, RJ, Fill, JC. Patterns of X chromosome inactivation in the Rett syndrome. Brain Dev 1990; 12: 131135.Google Scholar
28. Ellison, KA, Fill, CP, Terwilliger, J, et al. Examination of X chromosome markers in Rett syndrome: exclusion mapping with a novel variation on multilocus linkage analysis. Am J Hum Genet 1992; 50: 278287.Google Scholar
29. Schanen, C, Francke, U. A severely affected male born into a Rett syndrome kindred supports X-linked inheritance and allows extension of the exclusion map. Am J Hum Genet 1998; 63: 267269.Google Scholar
30. Sirianni, N, Naidu, S, Pereira, J, et al. Rett syndrome: confirmation of X-linked dominant inheritance, and localization of the gene to Xq28. Am J Hum Genet 1998; 63: 15521558.CrossRefGoogle ScholarPubMed
31. Xiang, F, Zhang, Z, Clarke, A, et al. Chromosome mapping of Rett syndrome: a likely candidate region on the telomere of Xq. J Med Genet 1998; 35: 297300.Google Scholar
32. Webb, T, Clarke, A, Hanefeld, F, et al. Linkage analysis in Rett syndrome families suggests that there may be a critical region at Xq28. J Med Genet 1998; 35: 9971003.Google Scholar
33. Schanen, NC. Molecular approaches to the Rett syndrome gene. J Child Neurol 1999; 14: 806814.Google Scholar
34. Amir, RE, Van den Veyver, IB, Wan, M, et al. Rett syndrome is caused by mutations in X-linked MECP2, encoding methyl-CpG-binding protein 2. Nature Genet 1999; 23: 185188.Google Scholar
35. Willard, HF, Hendrich, BD. Breaking the silence in Rett syndrome. Nature Genet 1999; 23: 127128.Google Scholar
36. Hendrich, BD. Methylation moves into medicine. Curr Biol 27 January 2000; 10: R60–R63.Google Scholar
37. Maraschio, P, Zuffardi, O, Dalla Fior, T, Tiepolo, L. Immunodeficiency, centromeric heterochromatin instability of chromosomes 1, 9 and 16, and facial anomalies: the ICF syndrome. J Med Genet 1988; 25: 173180.Google Scholar
38. Amir, RE, Van den Veyver, IB, Schultz, R, et al. Influence of mutation type and X chromosome inactivation on Rett syndrome phenotypes. Ann Neurol 2000; 47: 670679.Google Scholar
39. Huppke, P, Laccone, F, Kràmer, N, Engel, W, Hanefeld, F. Rett syndrome: analysis of MeCP2 and clinical characterization of 31 patients. Hum Molec Genet 2000; 9: 13691375.Google Scholar
40. Van den Veyver, IB, Zoghbi, HY. Methyl-CpG binding protein 2 mutations in Rett syndrome. Curr Opin Genet Dev 2000; 10: 275279.Google Scholar
40a. Francke, U. Spectrum of MECP2 mutations in Rett syndrome. World Congress on Rett Syndrome 2000; Symposium S–1;9 Google Scholar
41. Cheadle, JP, Gill, H, Fleming, N, et al. Long-read sequence analysis of the MECP2 gene in Rett syndrome patients: correlation of disease severity with mutation type and location. Hum Molec Genet 2000; 9: 11191129.CrossRefGoogle ScholarPubMed
42. Nan, X, Guy, J, Hendrich, B, et al. Biological function of the methyl-CPG binding protein MECP2 . World Congress on Rett Syndrome 2000; Abstract KS–II:2.Google Scholar
43. Christodoulou, J, Weaving, L, Ellaway, C, Leonard, H, Bennetts, B. MECP2 and Rett Syndrome (RS) – time for a mutation database? World Congress on Rett Syndrome 2000, PO–48:56.Google Scholar
44. Leonard, H, Bower, C. Is the girl with Rett syndrome normal at birth? Dev Med Child Neurol 1998; 40: 115121.Google Scholar
45. Jellinger, K, Armstrong, D, Zoghbi, HY, Percy, AK. Neuropathology of Rett syndrome. Acta Neuropathol 1988; 76: 142158.Google Scholar
46. Bauman, ML, Kemper, TL, Arin, DM. Microscopic observations of the brain in Rett syndrome. Neuropediatrics 1995: 26: 105108.Google Scholar
47. Oldfors, A, Sourander, P, Armstrong, D, et al. Rett syndrome: cerebellar pathology. Pediatr Neurol 1990; 6: 310314.Google Scholar
48. Armstrong, DD. The neuropathology of Rett syndrome: overview 1994. Neuropediatrics 1995; 26: 100104.Google Scholar
49. Haas, RH, Love, S. Peripheral nerve findings in Rett syndrome. J Child Neurol 1988: 3 (Suppl): 525530.Google Scholar
50. Oldfors, A, Hagberg, B, Nordgren, H, et al. Rett syndrome: spinal cord neuropathy. Pediatr Neurol 1988; 4: 172174.Google Scholar
51. Jellinger, K, Grisold, W, Armstrong, D, et al. Peripheral nerve involvement in the Rett syndrome. Brain Dev 1990; 12: 109114.Google Scholar
52. Kitt, CA, Wilcox, BJ. Preliminary evidence for neurodegenerative changes in the substantia nigra of Rett syndrome. Neuropediatrics 1995; 26: 114118.Google Scholar
53. Belichenko, PV, Hagberg, B, Dahlstròm, A. Morphological study of neocortical areas in Rett syndrome. Acta Neuropathol 1997; 93: 5061.Google Scholar
54. Nomura, Y, Segawa, M. Clinical features of the early stage of the Rett syndrome. Brain Dev 1990; 12: 1619.Google Scholar
55. Witt-Engerstròm, I. Age related occurrence of signs and symptoms in the Rett syndrome. Brain Dev 1992; 14: S11–S20.Google Scholar
56. Naidu, S, Hyman, S, Harris, EL, et al. Rett syndrome studies of natural history and search for a genetic marker. Neuropediatrics 1995; 26: 6366.Google Scholar
57. Glaze, DG, Frost, JD, Zoghbi, HY, et al. Rett’s syndrome: correlation of electroencephalographic characteristics with clinical staging. Arch Neurol 1987; 44: 10531056.Google Scholar
58. Robertson, R, Langill, L, Wong, PKH, Ho, HH. Rett syndrome: EEG presentation. Electroencephalogr Clin Neurophysiol 1988; 70: 388395.Google Scholar
59. Ho, HH, Wong, PK, Robertson, R. Rett syndrome: clinical profile and EEG abnormalities. Clin Invest Med 1988; 11: 234241.Google Scholar
60. Niedermeyer, E, Naidu, S. Further EEG observations in children with the Rett syndrome. Brain Dev 1990; 12: 5354.CrossRefGoogle ScholarPubMed
61. Elian, M, Rudolf, ND. EEG and respiration in Rett syndrome. Acta Neurol Scand 1991; 83: 123128.Google Scholar
62. Niedermeyer, E, Naidu, SB, Plate, C. Unusual EEG theta rhythms over central region in Rett syndrome: considerations of the underlying dysfunction. Clin Electroencephalogr 1997; 28: 3643.Google Scholar
63. Glaze, DG, Schultz, RJ, Frost, JD. Rett syndrome: characterization of seizures versus nonseizures. Electroencephalogr Clin Neurophysiol 1998; 106: 7983.Google Scholar
64. Guerrini, R, Bonanni, P, Parmeggiani, L, et al. Cortical reflex myoclonus in Rett syndrome. Ann Neurol 1998; 43: 472479.CrossRefGoogle ScholarPubMed
65. Yamanouchi, H, Kaga, M, Arima, M. Abnormal cortical excitability in Rett syndrome. Pediatr Neurol 1993; 9: 202206.Google Scholar
66. Heinen, F, Petersen, H, Fietzek, U, et al. Transcranial magnetic stimulation in patients with Rett syndrome: preliminary results. Europ Child Adolesc Psychiatry 1997; 6(Suppl 1): 6163.Google Scholar
67. Nezu, A, Kimura, S, Takeshita, S, Tanaka, M. Characteristic response to transcranial magnetic stimulation in Rett syndrome. Electroencephalogr Clin Neurophysiol 1998; 109: 100103.Google Scholar
68. Badr, GG, Witt-Engerstròm, I, Hagberg, B. Brain stem and spinal cord impairment in Rett syndrome: Somatosensory and auditory evoked responses investigations. Brain Dev 1987; 9: 517522.Google Scholar
69. Bader, GG, Witt-Engerstròm, I, Hagberg, B. Neurophysiological findings in the Rett syndrome, I:EMG, conduction velocity, EEG and somatosensory-evoked potential studies. Brain Dev 1989; 11: 102109.CrossRefGoogle ScholarPubMed
70. Nomura, Y, Segawa, M, Hasegawa, M. Rett syndrome – clinical studies and pathophysiological considerations. Brain Dev 1984: 6; 475486.Google Scholar
71. Nomura, Y, Segawa, M, Higurashi, M. Rett syndrome – an early catecholamine and indolamine deficient disorder? Brain Dev 1985; 7: 334341.Google Scholar
72. Nomura, Y, Segawa, M. Anatomy of Rett syndrome. Am J Med Genet 1986; 24: 289303.Google Scholar
73. Segawa, M, Nomura, Y. Pathophysiology of the Rett syndrome from the standpoint of polysomnography. Brain Dev 1990; 12: 5560.Google Scholar
74. Segawa, M, Nomura, Y. Polysomnography in the Rett syndrome. Brain Dev 1992; 14 (Suppl) S46–S54.Google Scholar
75. Felten, DL, Hallman, H, Jonsson, G. Evidence for a neurotrophic role of noradrenaline neurons in the postnatal development of rat cerebral cortex. J Neurocytol 1982; 11: 119135.Google Scholar
76. Perry, TL, Dunn, HG, Ho, HH, Crichton, JU. Cerebrospinal fluid values for monoamine metabolites, gamma aminobutyric acid, and other amino compounds in Rett syndrome. J Pediatr 1988; 112: 234238.Google Scholar
77. Lekman, A, Witt-Engerstròm, I, Holmberg, B, et al. CSF and urine biogenic amine metabolites in Rett syndrome. Clin Genet 1990; 37: 173178.Google Scholar
78. Lekman, A, Witt-Engerstròm, I, Gottfries, J, et al. Rett syndrome: biogenic amines and metabolites in postmortem brain. Pediatr Neurol 1989; 5: 357362.Google Scholar
79. Wenk, GL, Naidu, S, Moser, H. Altered neurochemical markers in Rett syndrome. Ann Neurol 1989; 26: 467.Google Scholar
80. Wenk, GL, Naidu, S, Casanova, MF, et al. Altered neurochemical markers in Rett’s syndrome. Neurology 1991; 41: 17531756.Google Scholar
81. Johnston, MV, Hohmann, C, Blue, M. Neurobiology of Rett syndrome. Neuropediatrics 1995; 26: 119122.Google Scholar
82. Berger-Sweeney, J. The effects of neonatal basal forebrain lesions on cognition: towards understanding the developmental role of the cholinergic basal forebrain. Internat J Dev Neurosci 1998; 16: 603612.Google Scholar
83. Wenk, GL. Alterations in dopaminergic function in Rett syndrome. Neuropediatrics 1995; 26: 123125.CrossRefGoogle ScholarPubMed
84. Wenk, GL. Rett syndrome: evidence for normal dopaminergic function. ibid. 1996; 27: 256259.Google Scholar
85. Kaufmann, WE, Taylor, CV, Hohmann, CF, et al. Abnormalities in neuronal maturation in Rett syndrome neocortex: preliminary molecular correlates. Eur Child Adolesc Psychiatry 1997; 6(Suppl 1): 7577.Google ScholarPubMed
86. Naidu, S. Rett syndrome: a disorder affecting early brain growth. Ann Neurol 1997; 42: 310.CrossRefGoogle ScholarPubMed
87. Li, Y, Holtzman, DM, Kromer, LF, et al. Regulation of TrkA and ChAT expression in developing rat basal forebrain: evidence that both exogenous and endogenous NGF regulate differentiation of cholinergic neurons. J Neurosci 1995; 15: 28882905.Google Scholar
88. Lin, LF, Doherty, DH, Lile, JD, et al. GDNF: a glial cell line derived neurotrophic factor for midbrain dopaminergic neurons. Science 1993; 260: 11301132.Google Scholar
89. Lappalainen, R, Lindholm, D, Riikonen, R. Low levels of nerve growth factor in cerebrospinal fluid of children with Rett syndrome. J Child Neurol 1996; 11: 296300.Google Scholar
90. Vanhala, R, Korkonen, L, Mikelsaar, M, et al. Neurotrophic factors in cerebrospinal fluid and serum of patients with Rett syndrome. J Child Neurol 1998; 13: 429433.Google Scholar
91. Riikonen, R, Vanhala, R. Levels of cerebrospinal fluid nerve-growth factor differ in infantile autism and Rett syndrome. Dev Med Child Neurol 1999; 41: 148152.Google Scholar
92. Wenk, GL, Hauss-Wegrzynriak, B. Altered cholinergic function in the basal forebrain of girls with Rett syndrome. Neuropediatrics 1999; 30: 125129.Google Scholar
93. Hohmann, CF, Berger-Sweeney, J. Cholinergic regulation of cortical development and plasticity. New twists to an old story. Perspect Dev Neurobiol 1998; 5: 401425.Google Scholar
94. Nomura, Y, Kimura, K, Arai, H, Segawa, M. Involvement of the autonomic nervous system in the pathophysiology of Rett syndrome. Eur Child Adolesc Psychiatry 1997; 6(Suppl 1): 4246.Google Scholar
95. Julu, PO, Kerr, AM, Hansen, S, et al. Functional evidence of brain stem immaturity in Rett syndrome. Eur Child Adolesc Psychiatry 1997; 6(Suppl 1): 4754.Google Scholar
96. Sekul, EA, Moak, JP, Schultz, RJ, et al. Electrocardiographic findings in Rett syndrome: explanation for sudden death? J Pediatr 1994; 125: 8082.Google Scholar
97. Dearlove, OR, Walker, RWM: Case Reports: Anaesthesia for Rett Syndrome. Paediatr Anaesth 1996; 6: 155158.Google Scholar
98. Ellaway, CJ, Sholler, G, Leonard, H, Christodoulou, J. Prolonged QT interval in Rett syndrome. Arch Dis Child 1999; 80: 470472.Google Scholar
99. Guideri, F, Acampa, M, Hayek, G, et al. Reduced heart rate variability in patients affected with Rett syndrome. A possible explanation for sudden death. Neuropediatrics 1999; 30: 146148.Google Scholar
100. Witt-Engerstròm, I, Kerr, A, eds. Workshop on autonomic function in Rett syndrome. Swedish Rett Center, Fròsòn, Sweden, May 1998. Brain Dev 1998; 20: 323326.Google Scholar
101. Lju ngberg, A-W, Hagberg, B. Rett syndrome, one-sided sympathectomy. Unilateral foot normalization. Eur Child Adolesc Psychiatry 1997; 6(Suppl 1): 55.Google Scholar
102. Armstrong, DD, Panigrahy, A, Sleeper, LA, Kinney, HC. Preliminary studies demonstrating increased [3H] lysergic acid diethylamide ([3H] LSD) binding to serotonin receptors in selected nuclei of the brain stem in Rett syndrome. Brain Dev 1998; 20: 323326.Google Scholar
103. Jessell, TM, Emson, PC, Paxinos, G, Cuello, AC. Topographic projections of Substance P and GABA pathways in the striato-and pallido-nigral system: a biochemical and immunohisto-chemical study. Brain Res 1978; 152: 487498.Google Scholar
104. Nikolaus, S, Huston, JP, Hasenohrl, RU. Reinforcing effects of neurokinin Substance Pin the ventral pallidum: mediation by the tachykinin NKI receptor. Eur J Pharmacol 1999; 370: 9399.Google Scholar
105. Kramer, MS, Cutler, N, Feighner, J, et al. Distinct mechanism for antidepressant activity by blockade of central Substance P receptors. Science 1998; 281: 16401645.Google Scholar
106. Nicoll, RA, Schenker, C, Leeman, SE. Substance P as a transmitter candidate. Ann Rev Neurosci 1980; 3: 227268.Google Scholar
107. Rimon, R, Greves, PL, Nyberg, F, et al. Elevation of Substance P-like peptides in the CSF of psychiatric patients. Biol Psychiatry 1984; 19: 509516.Google Scholar
108. Russell, IJ, Orr, MD, Littman, B, et al. Elevated cerebrospinal fluid levels of Substance Pin patients with the fibromyalgia syndrome. Arthritis Rheum 1994; 37: 15931601.Google Scholar
109. Matsuishi, T, Nagamitsu, S, Yamashita, Y, et al. Decreased cerebrospinal fluid levels of Substance P in patients with Rett syndrome. Ann Neurol 1997; 42: 978981.Google Scholar
110. Deguchi, K, Antalffy, BA, Twohill, LJ, et al. Substance P immunoreactivity in Rett syndrome. Pediatr Neurol 2000; 22: 259266.Google Scholar
111. Matsuishi, T, Urabe, F, Percy, AK, et al. Abnormal carbohydrate metabolism in cerebrospinal fluid in Rett syndrome. J Child Neurol 1994; 9: 2630.Google Scholar
112. Haas, RH, Nasirian, F, Hua, X, et al. Oxidative metabolism in Rett syndrome: 2. Biochemical and molecular studies. Neuropediatrics 1995; 26: 9599.Google Scholar
113. Budden, SS, Myer, EC, Butler, IJ. Cerebrospinal fluid studies in the Rett syndrome: biogenic amines and beta endorphins. Brain Dev 1990; 12: 8184.Google Scholar
114. Echenne, B, Bressot, N, Bassir, M, et al. Cerebrospinal fluid β-endorphin and cortisol study in Rett syndrome. J Child Neurol 1991; 6: 257262.Google Scholar
115. Nielsen, JB, Bach, FW, Buchholt, J, Lou, H. Cerebrospinal fluid β-endorphin in Rett syndrome. Dev Med Child Neurol 1991; 33: 406411.Google Scholar
116. Myer, EC, Tripathi, HL, Brase, DA, Dewey, WL. Elevated CSF β-endorphin immunoreactivity in Rett’s syndrome: report of 158 cases and comparison with leukemic children. Neurology 1992; 42: 357360.Google Scholar
117. Percy, AK, Glaze, DG, Schultz, RJ, et al. Rett syndrome: controlled study of an oral opiate antagonist, naltrexone. Ann Neurol 1994; 35: 464470.Google Scholar
118. Lekman, AY, Hagberg, BA, Svennerholm, LT. Membrane cerebral lipids in Rett syndrome. Pediatr Neurol 1991; 7: 186190.Google Scholar
119. Lekman, AY, Hagberg, BA, Svennerholm, LT. Cerebrospinal fluid gangliosides in patients with Rett syndrome and infantile neuronal ceroid lipofuscinosis. Eur J Paediatr Neurol 1999; 3: 119123.Google Scholar
120. Hamberger, A, Gillberg, C, Palm, A, Hagberg, B. Elevated CSF glutamate in Rett syndrome. Neuropediatrics 1992; 23: 212213.Google Scholar
121. Lappalainen, R, Riikonen, RS. High levels of cerebrospinal fluid glutamate in Rett syndrome. Pediatr Neurol 1996; 15: 213216.Google Scholar
122. Uldall, P, Hansen, FJ, Tonnby, B. Lamotrigine in Rett syndrome. Neuropediatrics 1993; 24: 339340.Google Scholar
123. Stenbom, Y, Tonnby, B, Hagberg, G. Lamotrigine in Rett syndrome: treatment experience from a pilot study. Eur Child Adolesc Psychiatry 1998; 7: 4952.Google Scholar
124. Giordano, L, Capovilla, G, Beccaria, F, et al. LTG therapy in 5 patients with Rett syndrome and epilepsy with the onset in the first 24 months of age. Bollettino-Lega Italiana Contra L’Epilessia 1998; 102–103: 151152.Google Scholar
125. McDonald, JW, Johnston, MV. Physiological and patho-physiological roles of excitatory amino acids during central nervous system development. Brain Res Rev 1990; 15: 4170.Google Scholar
126. Blue, ME, Naidu, S, Johnston, MV. Development of amino acid receptors in frontal cortex from girls with Rett syndrome. Ann Neurol 1999; 45: 541545.Google Scholar
127. Langlais, PJ, Walsh, FX, Bird, ED, Levy, HL. Cerebrospinal fluid neurotransmitter metabolites in neurologically normal infants and children. Pediatrics 1985; 75: 580586.Google Scholar
128. Blue, ME, Naidu, S, Johnston, MV. Altered development of glutamate and GABAreceptors in the basal ganglia of girls with Rett syndrome. Exp Neurol 1999; 156: 345352.Google Scholar
129. Satoi, M, Matsuishi, T, Yamada, S, et al. Decreased cerebrospinal fluid levels of β-phenylethylamine in patients with Rett syndrome. Ann Neurol 2000; 47: 801803.Google Scholar
130. Casanova, MF, Naidu, S, Goldberg, T, et al. Quantitative magnetic resonance imaging in Rett syndrome. J Neuropsychiatry 1991; 3: 366372.Google Scholar
131. Murakami, JW, Courchesne, E, Haas, RH, et al. Cerebellar and cerebral abnormalities in Rett syndrome: a quantitative MR analysis. AJR Am J Roentgenol 1992; 159: 177183.Google Scholar
132. Reiss, AL, Faruque, F, Naidu, S, et al. Neuroanatomy of Rett syndrome: a volumetric imaging study. Ann Neurol 1993; 34: 227234.Google Scholar
133. Subramaniam, B, Naidu, S, Reiss, AL. Neuroanatomy in Rett syndrome: cerebral cortex and posterior fossa. Neurology 1997; 48: 399407.Google Scholar
134. Nielsen, JB, Toft, PB, Reske-Nielsen, E, et al. Cerebral magnetic resonance spectroscopy in Rett syndrome. Failure to detect mitochondrial disorder. Brain Dev 1993; 15: 107112.Google Scholar
135. Hanefeld, F, Christen, HJ, Holzbach, U, et al. Cerebral proton magnetic resonance spectroscopy in Rett syndrome. Neuropediatrics 1995; 26: 126127.Google Scholar
136. Hashimoto, T, Kawano, N, Fukuda, K, et al. Proton magnetic resonance spectroscopy of the brain in 3 cases of Rett syndrome: comparison with autism and normal controls. Acta Neurol Scand 1998; 98: 814.Google Scholar
137. Pan, JW, Lane, JB, Hetherington, H, Percy, AK. Rett syndrome: 1H spectroscopic imaging at 4.1 Tesla. J Child Neurol 1999;14:524528.Google Scholar
138. Horská, A, Naidu, S, Herskovits, EH, et al. Quantitative 1H MR spectroscopic imaging in early Rett syndrome. Neurology 2000; 54: 715722.Google Scholar
139. Nielsen, JB, Friberg, L, Lou, H, et al. Immature pattern of brain activity in Rett syndrome. Arch Neurol 1990; 47: 982986.Google Scholar
140. Lappalainen, R, Liewendahl, K, Sainio, K, et al. Brain perfusion SPECT and EEG findings in Rett syndrome. Acta Neurol Scand 1997; 95: 4450.Google Scholar
141. Bjure, J, Uvebrant, P, Vestergren, E, Hagberg, B. Regional cerebral blood flow abnormalities in Rett syndrome. Eur Child Adolesc Psychiatry 1997; 6(Suppl 1): 6466.Google Scholar
142. Burroni, L, Aucone, AM, Volterrani, D, et al. Brain perfusion abnormalities in Rett syndrome: a qualitative and quantitative SPECT study with 99Tc(m)-ECD. Nucl Med Commun 1997; 18: 527534.CrossRefGoogle ScholarPubMed
143. Yoshikawa, H, Fueki, N, Suzuki, H, et al. Cerebral blood flow and oxygen metabolism in Rett syndrome. J Child Neurol 1991;6: 237242.Google Scholar
144. Harris, JC, Wong, DF, Wagner, HN, et al. Positron emission tomographic study of D2 dopamine receptor binding and CSF biogenic amine metabolites in Rett syndrome. Am J Med Genet 1986; 24(Suppl 1): 201210.Google Scholar
145. Snow, BJ, Tooyama, I, McGeer, EG, et al. Human positron emission tomographic [18F] fluorodopa studies correlate with dopamine cell counts and levels. Ann Neurol 1993; 34: 324330.Google Scholar
146. Pate, BD, Kawamata, T, Yamada, T, et al. Correlation of striatal fluorodopa uptake in the MPTP monkey with dopaminergic indices. Ann Neurol 1993; 34: 331338.Google Scholar
147. Trebossen, R, Bendriem, B, Ribeiro, MJ, et al. Validation of the three-dimensional acquisition mode in Positron Emission Tomography for quantitation of [18F] fluoro-Dopa uptake in human striata. J Cereb Blood Flow Metab 1998; 18: 951959.Google Scholar
148. Pietrzyk, U, Herholz, K, Fink, G, et al. An interactive technique for three-dimensional image registration: validation for PET, SPECT, MRI and CTbrain studies. J Nucl Med 1994; 35: 20112018.Google Scholar
149. Wong, DF, Ricaurte, G, Gründer, G, et al. Dopamine transporter changes in neuropsychiatric disorders. Adv Pharmacol 1998, 42: 219223.Google Scholar
150. Chiron, C, Bultreau, C, Loch, C, et al. Dopaminergic D2 receptor SPECTimaging in Rett syndrome: increase of specific binding in striatum. J Nucl Med 1993; 34: 17171721.Google Scholar
151. Naidu, S, Kaufmann, W, Abrams, M, et al. Neuroimaging studies in Rett syndrome. World Congress on Rett Syndrome 2000. Plenary Lecture-IV:6.Google Scholar
152. Cordes, M, Snow, BJ, Cooper, S, et al. Age-dependent decline of nigrostriatal dopaminergic function: a positron emission tomographic study of grandparents and their grandchildren. Ann Neurol 1994; 36: 667670.Google Scholar
153. Nomura, Y. Neurophysiology of Rett syndrome. World Congress on Rett Syndrome 2000. Plenary Lecture-II: 4.Google Scholar
154. Filipek, PA, Accardo, PJ, Ashwal, S, et al. Screening and diagnosis of autism: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Child Neurology Society. Neurology 2000; 55: 468479.Google Scholar
155. Chiron, C, Leboyer, M, Leon, F, et al. SPECT of the brain in childhood autism: evidence for a lack of normal hemispheric asymmetry. Dev Med Child Neurol 1995; 37: 849860.Google Scholar
156. Chugani, DC, Muzik, O, Behen, M, et al. Developmental changes in brain serotonin synthesis capacity in autistic and nonautistic children. Ann Neurol 1999; 45: 287295.Google Scholar
157. Ellaway, C, Buchholz, T, Smith, A, Leonard, H, Christodoulou, J. Rett syndrome: significant clinical overlap with Angelman syndrome but not with methylation status. J Child Neurol 1998; 13: 448451.Google Scholar
158. Budden, SS. Management of Rett syndrome: a ten-year experience. Neuropediatrics 1995; 26: 7577.Google Scholar
159. Budden, SS. Rett syndrome: habilitation and management reviewed. Eur Child Adolesc Psychiatry 1997; 6(Suppl 1): 103107.Google Scholar