Cerebellar Sclerosis

In cerebellar sclerosis, grossly, the cerebellar cortex is atrophic and sclerotic, more severely in the depth and

figure 14.8

Multicystic leukomalacia in a 6-year-old quadriplegic, epileptic, and speechless boy. He was delivered by forceps at full term and was cyanotic for 3 days. The mother's pregnancy was complicated by episodes of vaginal bleeding and premature separation of the placenta. Transverse sections of the brain reveal diffuse multicystic necrosis of the white matter extending from the frontal to the occipital lobes. The cortex is necrotic in some areas, and relatively preserved in others.

figure 14.8

Multicystic leukomalacia in a 6-year-old quadriplegic, epileptic, and speechless boy. He was delivered by forceps at full term and was cyanotic for 3 days. The mother's pregnancy was complicated by episodes of vaginal bleeding and premature separation of the placenta. Transverse sections of the brain reveal diffuse multicystic necrosis of the white matter extending from the frontal to the occipital lobes. The cortex is necrotic in some areas, and relatively preserved in others.

figure 14.9

A porencephalic cyst occupies the entire width of the cerebral wall. The overlying cortex is necrotic (myelin stains).

figure 14.9

A porencephalic cyst occupies the entire width of the cerebral wall. The overlying cortex is necrotic (myelin stains).

figure 14.10

Status marmoratus. Patchy whitish discoloration in thalamus from bundles of hypermyelinated nerve fibers.

figure 14.10

Status marmoratus. Patchy whitish discoloration in thalamus from bundles of hypermyelinated nerve fibers.

figure 14.12

Bilirubin encephalopathy, acute. Medulla. Deposits of bilirubin pigments stain the inferior olivary nuclei yellow.

figure 14.12

Bilirubin encephalopathy, acute. Medulla. Deposits of bilirubin pigments stain the inferior olivary nuclei yellow.

i figure 14.1 1

Cerebellum showing extensive Purkinje cell losses, some granular cell losses, and prominent Bergmann astrocytosis.

walls of folia. Histologically, it displays extensive Purkinje cell and variable granule cell losses. A prominent Bergmann astrocytic layer forms at the site of lost Pur-kinje cells. The white matter shows astrocytic fibrillary gliosis, and the dentate nuclei show neuronal losses (Fig. 14.11).

METABOLIC AND TOXIC DISEASES Bilirubin Encephalopathy

Bilirubin encephalopathy or kernicterus results from elevated unconjugated serum bilirubin: 20 mg/100 mL

or higher in mature infants, and lower in immature infants.

Hyperbilirubinemia may result from hemolytic anemia due to incompatibility of RH groups; failure of bilirubin conjugation due to liver damage; congenital enzyme (glucuronyl transferase) deficiency; and certain drugs. Unconjugated bilirubin crosses the blood-brain barrier to injure selected neuronal groups.

Clinical manifestations during the neonatal period are lethargy, hypertonia with opisthotonus, loss of Moro reflex, and seizures. Survivors of the encephalopathy are mentally retarded and display choreoathetosis, dysto-nia, ataxia, gaze palsy, and hearing deficit.

Pathology: the most severely affected regions in a symmetric distribution, are the globus pallidus, sub-thalamic nucleus and hippocampus. Variably involved structures include the thalamus; mammillary bodies; lateral geniculate bodies; substantia nigra; brainstem reticular nuclei; third, fourth, and eighth cranial nerve nuclei; and the dentate and olivary nuclei. Grossly, during the acute stage, the affected regions, in unfixed preparation, are bright yellow from deposits of bilirubin pigments (bilirubin pigments dissolve in formalin (Fig. 14.12). Histologically, the neurons show chromatolysis, eosinophilia, and vacuolization of the perikaryon. Neurons and glial cells may contain bilirubin pigments. Chronic cases show neuronal losses and replacement astrocytosis in the affected regions (Fig. 14.13).

figure 14.13

Bilirubin encephalopathy, late sequelae, in a 14-year-old severely retarded, deaf, spastic-athetotic boy. Dense astrogliosis in (A) subthalamic nucleus and (B) inferior olivary nuclei and floor of fourth ventricle.

table 14.3.

Fetal Alcohol Syndrome

Craniofacial anomalies:

Small head, narrow palpebral fissure, low nasal bridge, small midface, thin upper lip Low-birth weight Growth retardation Poor motor skills Hearing deficit Cognitive deficits Behavioral disorder

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