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Paper 4
Published in Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw, The Final FRCR, 2020
Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw
Lissencephaly is an abnormally smooth brain surface. The cortex is thickened and the lateral ventricles may be dilated, especially posteriorly. The cerebellum is usually not affected. Pachygyria (broad gyri) and agyria (no gyri) also exist as subtypes within this spectrum of disorders.
Schimmelpenning–Feuerstein–Mims Syndrome
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
Neurologic abnormalities are present in >60% of SFM syndrome cases. Of these, seizures (epilepsy) affect 67% of patients from the first year of life and are resistant to conventional antiepileptic drugs. Mental retardation is found in 61% of cases. Hemimegalencephaly (one side of the brain being larger than the other) is observed in 72% of the patients and causes infantile spasms (a combination of nodding spasms, hypsarrhythmia on EEG, and mental retardation). Developmental delay and intellectual impairment are sometimes observed as a result of damages to certain cranial nerves by altered structures of the brain (e.g., hemimegalencephaly), malformation (dysplasia) of certain brain vessels, absence (agenesis) of the nerve bundle connecting the two cerebral hemispheres (corpus callosum), and defects of the folds of the brain such as agyria (a smooth brain lacking the distinctive folds), microgyria (abnormally small folds), or pachygyria (abnormally thickened folds), as well as by excessive fluid accumulation around the brain (congenital hydrocephalus).
Paediatrics
Published in Vincent Helyar, Aidan Shaw, The Final FRCR, 2017
Means ‘smooth’, same as agyria (pachygyria = broad, flat gyri). Due to arrested neuronal migration. The brain looks as it should at 18–20 weeks of gestation. It is the most severe malformation of cortical development.
Child with cerebral malformations and epilepsy
Published in International Journal of Neuroscience, 2018
Ying Sun, Xuehua Shen, Qiubo Li, Qingxia Kong
MRI of the child showed cerebral malformations. The brain anomalies of BWCFF are related to impaired neuronal migration and are predominately located in anterior areas [14]. Abnormal neuronal migration mainly occurs in the critical period of the migration of neurons and early pregnancy. Various factors, such as heredity and infection, may have inhibited the migration and disrupted this process. The pathological characteristics include abnormal neurons, abnormal migration, large neurons and abnormal cortical stratification, thus resulting in abnormal synaptic connections and network structures. Pathological changes may be important causes of various abnormal clinical manifestations, such as ID, developmental delay, intractable seizure and characteristic head and face deformities [15,16]. Pachygyria – frontal or perisylvian, and lissencephaly with diffuse agyria have been reported [6,17,18]. Lateral ventricle may be slightly expanded and a few have periventricular nodules. The corpus callosum often expressed as short and thick or may be hypoplastic or absent [6]. Pachygyria and other structural cerebral changes are associated with mild to profound ID and are often consistent with the severity of the cortical malformation [6,19]. Other neurological features include generalized hypotonia or spasticity of the lower limbs [6,19].
Sleep EEG of Microcephaly in Zika Outbreak
Published in The Neurodiagnostic Journal, 2018
Paulo Afonso Medeiros Kanda, Aline de Almeida Xavier Aguiar, Jose Lucivan Miranda, Alexandre Loverde Falcao, Claudia Suenia Andrade, Luigi Neves dos Santos Reis, Ellen White R. Bacelar Almeida, Yanes Brum Bello, Arthur Monfredinho, Rafael Guimaraes Kanda
EEG rhythmic activity consisting of continuous or frequent, diffuse or localized, slow or fast frequencies is common in Zmc associated with epilepsy. It is nonspecific and can be seen with and without hypsarrhythmia. Five of our Zmc patients (cases 14, 16, 17, 19, and 22) presented distinct runs of rhythmic activity generalized or localized in frontal and midline regions (Figure 10), whereas Carvalho et al. (2017) reported just 1 case of sinusoidal theta rhythmic activity, starting in right Rolandic region and spreading to both hemispheres. Runs of theta, delta, or alpha activity seem to be nonspecific, but common in MC. For example, Dulac et al. (1983) reported on 4 infants with agyria and MC. All were developmentally delayed, and 2 had infantile spasms. Their EEGs showed a slow background rhythm, and, as in 8 of our cases, Dulac et al.’s EEGs were characterized by runs of generalized, very-high-amplitude rhythms in the alpha range, associated with delta waves, with infrequent spikes and abnormal sleep architecture. In our cases of ZIKV, these runs of rhythmic activity ranging from 4.5 to 24 Hz were associated with hypsarrhythmia or diffuse slowing.
Prenatal and Postnatal Zika Intrauterine Infection: Diagnostic Imaging Techniques and Placental Pathology
Published in Fetal and Pediatric Pathology, 2023
Pedro Teixeira Castro, Heron Werner, Edward Araujo Júnior, Maria Paola Bonasoni, Gabriele Tonni
Initially, the vertical transmission of ZIKV was perceived by the unusual increase of fetuses and newborn with microcephaly, especially if primary infection was contracted during the first trimester of pregnancy [26,27]. Microcephaly is defined as the head circumference (HC) below the 3rd centile or two standard deviations below the mean value for expected gestational age [5] and may be the result of severe impaired cerebral growth during intrauterine life, determining a reduction of the hydrostatic pressure, causing the collapse of the skull and suture overlapping. This finding can be observed in other infections as cytomegalovirus and is denominated fetal brain disruption sequence [28]. The fetal lesions caused by CZS are characterized by a variety of lesions that go beyond microcephaly and skull collapse [29,30]. Abnormal neuronal migration leads to lissencephaly, pachygyria, agyria, polymicrogyria, heterotopia, and dysgenesis of corpus callosum. On the whole, encephalic shrinkage can cause ventriculomegaly ex vacuo, increased posterior fossa and pericerebral space. Eyes can also be affected, with pigmented retinal mottling, choriorretinal atrophy, glaucoma, and optical nerve anomalies. Microphthalmia and anophthalmia have also been described. Secondary to cerebral lesions, limb contractures such as arthrogryposis, talipes equinovarus and hip dislocation can be present. In a pioneristic work, Werner et al. [27] were also able to correlate neuroimaging findings with 3 D physical model in a fetus with proven CZS. Many of the lesions described above were found in this case. The fetal brain disruption syndrome is easily recognized, the increased pericerebral space and ventriculomegaly are more frequently encountered in CZS than TORCHs infections [28].