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Flashcards in Developmental and Hereditary Disorders Deck (41)
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1
Q
  1. In Hirschsprung’s disease, neural crest cells fail to migrate normally early in fetal development and produce potentially fatal complications within months of birth because of disturbed
    a. Intestinal motility
    b. Bladder control
    c. Swallowing
    d. Bile secretion
    e. Cardiac rhythms
A

A

(Victor, p 574.) Infants with this defect in develop ment of the myenteric plexus are susceptible to intestinal obstruction and megacolon development. The affected infants are often misconstrued as merely colicky shortly after birth, but recurrent bouts of constipation, diarrhea, and vomiting point to more serious disturbances of intestinal motility. Intestinal obstruction is likely to become complete within the first year of life and may be fatal if not surgically corrected. The failure of migration of neural crest cells has been linked to a defect on chromosome 10.

2
Q
  1. A newborn infant has a cystic swelling at the base of the spine that is covered with hyperpigmented skin and some coarse hair. Which of the following is the most likely explanation?
    a. Mongolian spot
    b. Spina bifida occulta
    c. Nevus flammeus
    d. Meningocele
    e. Encephalocele
A

D

(Victor, p 1062.) The Mongolian spot is a benign discoloration of the newborn’s skin at the base of the spine. It is usually oval, well circumscribed, flat, and slightly hyperpigmented or otherwise discolored. Spina bifida occulta is a defect in the superior elements of the spinal column that is unassociated with meningeal or spinal cord abnormalities. It may be evidenced superficially by a dimple in the skin or a tuft of hair overlying the base of the spine. When there is evagination of the meninges (dura mater and pia arachnoid) about the cord or cauda equina through the defect in the spine, the condition is called a meningocele. Extrusion of meningeal and neural elements together is called a meningomyelocele. An encephalocele is a defect in the skull with extrusion of brain. Nevus flammeus is a congenital, port-wine spot, usually developing on the face.

3
Q

At age 5, a child is noted to have the loss of ankle jerks. At age 10, limb ataxia develops, followed by a peripheral neuropathy. During adolescence, retinitis pigmentosa develops. Acanthocytosis is present.

  1. These are all characteristic of which of the following?
    a. Multiple sclerosis (MS)
    b. Sickle cell disease
    c. Abetalipoproteinemia
    d. Progressive multifocal leukoencephalopathy (PML)
    e. HIV subacute encephalomyelitis
A

C

(Rowland, pp 552–553.) Abetalipoproteinemia (Bassen-Kornzweig syndrome) usually becomes symptomatic during early childhood. The peripheral blood smear will exhibit abnormally shaped erythrocytes (acanthocytes), and the plasma lipid profile will reveal a very low cholesterol and triglyceride content. Acanthocytes are spiked or crenated RBCs. These are an unusual hematologic finding in patients with ataxia and are often diagnostic of abetalipoproteinemia. Autopsy examination of the CNS in patients with abetalipoproteinemia reveals posterior column and spinocerebellar tract degeneration. The initial complaints are similar to the spinocerebellar signs of Friedreich’s disease. Position sense is lost and extensor plantar responses develop as the disease progresses. As is true for Friedreich’s disease, dementia is not an obvious part of the syndrome. Deficits accumulate over the course of years. Vitamin E supplementation may retard the disease’s progression. The differential diagnosis of retinitis pigmentosa is broad, and includes many other conditions besides abetalipoproteinemia: mitochondrial diseases, Bardet-Biedl syndrome, Laurence-Moon syndrome, Friedreich’s ataxia, and Refsum’s disease. It may also occur alone as a hereditary disorder linked to chromosome 3. It is characterized by a degeneration of all layers of the retina. Because it is a noninflammatory condition, retinitis is actually something of a misnomer.

4
Q

At age 5, a child is noted to have the loss of ankle jerks. At age 10, limb ataxia develops, followed by a peripheral neuropathy. During adolescence, retinitis pigmentosa develops. Acanthocytosis is present.

  1. In this disorder, chylomicrons, very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL) are largely absent in the serum as a consequence of a mutation in which gene?
    a. Microsomal triglyceride transfer protein (MTP)
    b. Huntingtin
    c. Amyloid precursor protein
    d. Dystrophin
    e. Transfer RNA (tRNA)
A

A

(Rowland, pp 552–553.) This disorder appears to be due to a mutation in the gene that encodes a subunit of the MTP, which results in impaired VLDL formation and consequent decreased vitamin E delivery to the peripheral and central nervous system. In addition to an abnormal plasma lipid profile, patients have disturbed fat absorption. Presumably, it is the disturbed lipid that deforms the erythrocyte cell wall, but erythrocyte production levels are relatively normal. Fat is increased in the liver, and patients exhibit lactose intolerance. Central nervous system amyloid collections develop in Alzheimer’s disease.

5
Q
  1. In this tomogram of the base of the skull, the first cervical vertebra is
    a. Unremarkable
    b. Fused to the base of the skull
    c. Completely absent
    d. Displaced dorsally
    e. Incorporated into the odontoid process (od)
A

B

(Osborn, pp 815–816.) In the tomogram, the first cervical vertebra, or atlas, is incompletely formed. The most ventral elements are apparent to the left of the left-pointing arrowhead, but the cortical bone of these elements is continuous with that of the skull. The elements of C1 that have formed have simply fused to the base of the skull. This assimilation of the atlas to the base of the skull is a congenital abnormality. It is often associated with a Chiari malformation of the hindbrain.

6
Q
  1. The second cervical vertebra extends above the level of the foramen magnum and places the patient at high risk of having
    a. A meningoencephalocele
    b. A myelomeningocele
    c. Syringobulbia
    d. Syringomyelia
    e. Brainstem compression
A

E

(Osborn, pp 815–816.) This abnormally situated axis (C2) qualifies as basilar invagination of the skull. If the medulla oblongata is situated at a normal level, it is at risk of compression, but posterior fossa contents may be so caudally displaced that pontine structures are also at risk of compression. Hydrocephalus may develop with this degree of basilar invagination by virtue of obstruction of the flow of CSF through the foramen magnum. Syringomyelia or syringobulbia are occasionally associated with this anatomic variant, but they probably develop as a consequence of cervical cord or brainstem damage.

7
Q
  1. In view of the unusually wide separation (double-barbed arrow) of caudal elements of the atlas from the odontoid process, one should suspect
    a. Instability of the atlantoaxial joint
    b. Hemorrhage into the atlantoaxial joint
    c. Fusion of C2 to C3
    d. Fracture of the odontoid process
    e. Fracture of the C2 spinous process
A

A

(Victor, p 1327.) The separation between the atlas and the odontoid process of the axis may change by several millimeters with flexion and extension of the neck. Extremes of position may actually be dangerous because of compression of the brainstem or of major arteries coursing through the foramen magnum. Instability of the joint may develop with fracture of the odontoid process, but in that situation the body of C2, rather than the odontoid process, will exhibit excessive slip in relation to C1 when the neck is flexed or extended. Fusion of other cervical vertebrae is not unusual in patients exhibiting anomalies at the base of the skull.

8
Q
  1. A 5-year-old boy has mental retardation, homonymous hemianopsia, and hemiparesis. He had infantile spasm and still has epilepsy. Head CT reveals calcifications in the cerebral cortex in a railroad track pattern. Which of the following does this child most likely have?
    a. Glioblastoma multiforme
    b. Oligodendroglioma
    c. Acoustic schwannoma
    d. Craniopharyngioma
    e. Sturge-Weber syndrome
A

E

(Greenberg, 2/e, p 601.) All of these disturbances will produce intracranial calcifications in some cases. The calcifications in Sturge-Weber syndrome follow the gyral pattern of the cerebral cortex and consequently produce the railroad track pattern that is evident on plain x-ray of the skull. Calcium is deposited in the brain of the patient with Sturge-Weber syndrome, presumably because the abnormal vessels overlying the brain allow calcium, as well as iron, across the defective blood-brain barrier. Craniopharyngioma and acoustic schwannoma produce calcifications, but these are obviously outside the cerebral cortex.

9
Q
  1. A 35-year-old woman has prenatal testing done. The testing reveals that her child will have phenylketonuria (PKU). With PKU, serum may exhibit dangerously high levels of
    a. Creatine phosphokinase (CPK)
    b. Nicotinamide
    c. Phenylketone
    d. Lactate dehydrogenase
    e. Phenylalanine
A

E

(Victor, pp 1008–1009.) Phenylketonuria is inherited as an autosomal recessive trait. It occurs in at least two forms. In one form, intolerance of phenylalanine is extreme, and dietary intake of that amino acid must be restricted from birth. Alternatively, some persons have
hyperphenylalaninemia without PKU. This latter group does not suffer the CNS damage seen with in utero exposure to high phenylalanine levels. Such in utero exposure will occur if the mother is homozygous for PKU. If the mother is normal, infants with PKU are born with essentially normal nervous systems. Damage develops after birth in the susceptible group as serum phenylalanine levels rise.

10
Q
  1. A 4-year-old previously healthy girl develops an intermittent red, scaly rash over her face, neck, hands, and legs. This is followed by developmental delay, emotional lability, and episodic cerebellar ataxia. She is diagnosed with Hartnup’s disease. Her condition may respond to large supplementary doses of
    a. Vitamin C
    b. Nicotinamide
    c. Thiamine
    d. Pyridoxine
    e. α tocopherol
A

B

(Victor, pp 1009–1010.) With Hartnup’s disease there is intestinal malabsorption of tryptophan and other neutral amino acids. Tryptophan serves as a precursor for nicotinamide, but with more than 400 mg of nicotinamide daily, the tryptophan malabsorption becomes less problematic. Inheritance appears to be autosomal recessive. Affected children develop a scaly erythematous rash on the face similar to that seen with pellagra. The ataxia exhibited may be episodic.

11
Q
  1. Hepatosplenomegaly is most likely with
    a. Tay-Sachs disease
    b. Niemann-Pick disease
    c. Alpers’ disease
    d. Subacute necrotizing encephalopathy
    e. Wilson’s disease (hepatolenticular degeneration)
A

B

(Victor, pp 997–998.) Niemann-Pick disease is inherited as an autosomal recessive trait. By 9 months of age, patients with the infantile form usually have prominent hepatosplenomegaly. A deficiency of sphingomyelinase in hepatocytes is diagnostic for the disease.

12
Q
  1. A 25-year-old woman with epilepsy is taking divalproex sodium during the first trimester of pregnancy. She is at slightly increased risk of having children with which of the following?
    a. Holoprosencephaly
    b. Defects of neural tube closure
    c. Medulloblastoma
    d. Agenesis of the corpus callosum
    e. Kallmann syndrome
A

B

(Greenberg, 5/e, p 274.) To what extent the antiepileptic divalproex sodium increases the risk of defects of neural tube closure, such as meningomyelocele, is debatable, but there is at least a slight increase in the risk. Many agents have been linked to problems with neural tube formation or closure, but none causes problems in a large segment of the population. Colchicine, papaverine, and caffeine, as well as irradiation, hyperthermia, antimetabolites, and salicylates, may increase the risk of neural tube malformations. The vitamin most clearly implicated in cases involving hypervitaminosis is vitamin A. Congenital malformations as a group are slightly increased in the offspring of women with epilepsy even if they are not taking antiepileptic drugs before or during pregnancy. The importance of folate supplementation in women with a prior history of neural tube defect has been shown in several studies and is the basis of the recommendation for the use of folate supplementation during the first trimester of pregnancy. Agenesis of the corpus callosum is a component of several developmental disorders of the CNS, including Chiari syndromes. Kallmann syndrome is a congenital disturbance of the hypothalamus that results in anosmia, hypogonadism, and other maturational problems that become more evident when puberty fails to occur.

13
Q
  1. With agenesis of the corpus callosum, magnetic resonance imaging (MRI) will reveal
    a. Atrophy of the frontal lobes
    b. Abnormally shaped lateral and third ventricles
    c. Cerebellar aplasia
    d. Schizencephaly
    e. Encephaloclastic porencephaly
A

B

(Greenberg, 2/e, p 586–587.) On coronal sections of the brain, the lateral ventricles will have a typical batwing conformation if the patient has agenesis of the corpus callosum. The third ventricle may be dilated and may open onto the surface of the brain. Patients with this congenital anomaly may be asymptomatic or may exhibit a variety of cognitive disorders. In Aicardi syndrome, agenesis of the corpus callosum is associated with retardation, epilepsy, vertebral anomalies, and chorioretinitis.

14
Q

A boy has the onset of difficulty walking at 16 months. Reflexes are decreased. Over the course of several months, the patient becomes dysarthric and mental functioning decreases. Testing reveals that the patient has a deficiency of arylsulfatase A.

  1. Which of the following does this patient most likely have?
    a. Sandhoff’s disease
    b. Tay-Sachs disease
    c. Gaucher’s disease
    d. Metachromatic leukodystrophy
    e. McArdle’s disease
A

D

(Rowland, pp 521–523.) Hexosaminidase deficiencies produce Sandhoff’s and Tay-Sachs diseases. Glucocerebrosidase is deficient in Gaucher’s disease. Phosphofructokinase deficiency is usually symptomatic as a disturbance of skeletal muscle function. The enzymatic defect in metachromatic leukodystrophy is transmitted in an autosomal recessive fashion. The affected person usually has retardation, ataxia, spasticity, and sensory disturbances, but individual elements of this disorder may appear alone in less serious cases. The disease is usually symptomatic during infancy.

15
Q

A boy has the onset of difficulty walking at 16 months. Reflexes are decreased. Over the course of several months, the patient becomes dysarthric and mental functioning decreases. Testing reveals that the patient has a deficiency of arylsulfatase A.

  1. This diagnosis can usually be made on the basis of which of the following?
    a. MRI
    b. Nerve biopsy
    c. Red blood cell (RBC) morphology
    d. Cerebrospinal fluid (CSF) cell morphology
    e. Electroencephalography (EEG)
A

B

(Rowland, pp 521–523.) Sulfatide granules may be evident in nerve tissue, as well as in tissue outside the nervous system, in persons with metachromatic leukodystrophy. The disease is usually fatal within a few years of obvious symptoms. At autopsy, there may be evidence of dysmyelination or demyelination in the CNS, as well as in the peripheral nervous system.

16
Q
  1. A 15-year-old boy has moderate mental retardation, attention deficit disorder, a long face, enlarged ears, and macroorchidism. Development has been steady but always at a delayed pace. The most likely cause for this patient’s low intelligence is which of the following?
    a. Turner syndrome
    b. Klinefelter syndrome
    c. Fragile X syndrome
    d. Reye syndrome
    e. Tuberous sclerosis
A

C

(Bradley, p 83.) With the fragile X syndrome, the terminal elements of the long arm of the abnormal X chromosome appear stretched or broken away from the rest of the chromosome. Retardation usually becomes evident during childhood. Affected men have large ears, a high-arched palate, hypotelorism, and large testes. Autism also occurs among affected men.

17
Q
  1. A 15-year-old boy has moderate mental retardation, attention deficit disorder, a long face, enlarged ears, and macroorchidism. Development has been steady but always at a delayed pace. Women carrying chromosomes for this disorder
    a. Are invariably normal
    b. Have mild retardation in about one-half of cases
    c. Have high-arched palates and hypotelorism
    d. Have hyperextensible joints
    e. Have prominent thumbs
A

B

(Victor, p 1067.) Men with the fragile X syndrome have hyperextensible joints and prominent thumbs, but carrier women may appear quite normal. The abnormal chromosome may be detected in fetal lymphocytes and fibroblasts, thereby allowing for prenatal screening. Epilepsy develops in many affected persons, but the seizures are usually easily controlled, unlike the case with other hereditary causes of epilepsy.

18
Q

A 35-year-old man complains of stumbling and slurred speech. His problem started several months ago and has progressed slowly but consistently. On neurologic examination, he is found to have scanning speech, nystagmus, limb dysmetria, and kinetic tremor. His intellectual function is normal.

  1. The most appropriate initial investigation is
    a. Lumbar puncture
    b. Serum drug screen
    c. Routine urinalysis
    d. Posterior fossa myelogram
    e. Precontrast CT scan
A

E

(Swaiman, pp 539–540.) This man has signs of cerebellar dysfunction. That the deficit has been slowly progressive and is not associated with cognitive dysfunction makes it especially likely that a structural lesion in the posterior fossa is responsible for the deficit. Because the lesion need not disturb the external shape of the cerebellum, a posterior fossa myelogram will not necessarily yield an answer. The CT scan will show if there is an intraparenchymal or extraparenchymal lesion. Drug abuse is not likely to be a factor in this cerebellar syndrome, because all the phenomena that are observed on examination are coordination problems rather than combined cognitive and motor functions.

19
Q

A 35-year-old man complains of stumbling and slurred speech. His problem started several months ago and has progressed slowly but consistently. On neurologic examination, he is found to have scanning speech, nystagmus, limb dysmetria, and kinetic tremor. His intellectual function is normal.

  1. Admission studies include a hematocrit of 55% and a routine urinalysis, which reveals excess protein and some RBCs in the urine. Urine culture is negative. The initial physical examination reveals an enlarged liver and spleen. Additional physical findings will most likely include
    a. A Kayser-Fleischer ring around the cornea
    b. Hypopigmented (ash leaf) spots on the trunk
    c. Telangiectasias in the fundi on retinal examination
    d. Bilateral hearing loss
    e. Generalized hyporeflexia
A

C

(Swaiman, pp 539–540.) The association of erythrocytosis with cerebellar signs, microscopic hematuria, and hepatosplenomegaly suggests von Hippel-Lindau syndrome. This hereditary disorder is
characterized by polycystic liver disease, polycystic kidney disease, retinal angiomas (telangiectasia), and cerebellar tumors. This is an autosomal dominant inherited disorder with variable penetrance. Men are more commonly affected than women. Although neoplastic cysts may develop in the cerebellum in persons with von Hippel-Lindau syndrome, these usually do not become sufficiently large to cause an obstructive hydrocephalus. Other abnormalities that occur with this syndrome include adenomas in many organs. Hemangiomas may be evident in the bones, adrenals, and ovaries. Hemangioblastomas may develop in the spinal cord or brainstem, as well as in the cerebellum. This syndrome is not associated with acoustic schwannomas that could cause bilateral hearing loss, and it is not accompanied by peripheral neuropathy, which could cause diffuse hyporeflexia.

20
Q

A 35-year-old man complains of stumbling and slurred speech. His problem started several months ago and has progressed slowly but consistently. On neurologic examination, he is found to have scanning speech, nystagmus, limb dysmetria, and kinetic tremor. His intellectual function is normal.

  1. A postcontrast computed tomography (CT) scan reveals a cyst and two smaller masses in the left cerebellar hemisphere. Your recommenda¬tion is that the patient
    a. Submit to surgical resection of the cerebellar lesions as soon as possible
    b. Submit to radiation therapy of the cerebellar lesions immediately
    c. Have follow-up MRI to look for involution of the lesions
    d. Have a diagnostic lumbar puncture to look for evidence of parasitic infestation of the brain
    e. Have a needle biopsy of the cerebellum to establish the histology of the cystic lesion
A

A

(Swaiman, pp 539–540.) The cystic lesion and the other cerebellar lesions are most likely hemangioblastomas. These hemangioblastomas often bleed and produce potentially lethal intracranial hematomas. Radiation therapy and needle biopsies would increase the risk of bleeding. Rather than spontaneously involuting, these lesions generally enlarge and become more unstable as time passes. Intracerebellar hemorrhage is increasingly likely as time passes.

21
Q

A 35-year-old man complains of stumbling and slurred speech. His problem started several months ago and has progressed slowly but consistently. On neurologic examination, he is found to have scanning speech, nystagmus, limb dysmetria, and kinetic tremor. His intellectual function is normal.

  1. Within 6 years of his initial visit, the patient returns with a pathologic fracture of his spine. Biopsy reveals metastatic cancer. The source of the tumor is most likely the
    a. Cerebral hemisphere
    b. Cerebellar hemisphere
    c. Liver
    d. Kidney
    e. Spleen
A

D

(Swaiman, pp 539–540.) Von Hippel-Lindau syndrome is associated with a high incidence of renal carcinomas. These malignant renal tumors usually develop years after the cerebellar hemangioblastomas, liver disease, or polycystic renal disease becomes symptomatic. People surviving intracranial hemorrhages caused by the intracerebellar hemangioblastomas often succumb to metastatic renal carcinoma. Treating the intracranial lesions does nothing to reduce the risk of metastatic renal cancer.

22
Q

An infant has a head CT performed because of a large head and failure to thrive. The diagnosis of hydrocephalus is made.

  1. Congenital hydrocephalus may develop as a consequence of which first-trimester maternal disorder?
    a. Complicated migraine
    b. Viral infection
    c. Pseudotumor cerebri
    d. Chorea gravidarum
    e. Intervertebral disk herniation
A

B

(Greenberg, 2/e, p 597. Rowland, pp 5142–5143.) A maternal infection with mumps or rubella virus may produce aqueductal stenosis and, as a consequence, hydrocephalus. The aqueduct of Sylvius connects the third ventricle to the fourth ventricle. The lateral and third ventricles enlarge as the choroid plexus produces fluid that cannot migrate to the subarachnoid space to be reabsorbed.

23
Q

An infant has a head CT performed because of a large head and failure to thrive. The diagnosis of hydrocephalus is made.

  1. Uncorrected congenital hydrocephalus will usually produce which of the following?
    a. Dolichocephaly
    b. Brachycephaly
    c. Holoprosencephaly
    d. Macrocephaly
    e. Microcephaly
A

D

Victor, pp 661–662.) Congenital hydrocephalus usually requires shunting to avoid progressive enlargement of the head and thinning of the brain mantle. Dolichocephaly and brachycephaly refer to head shapes, the former being a long, narrow head and the latter a broad head. Neither of these is necessarily associated with any abnormality. Holoprosencephaly is a failure in development of the midline division of the brain, which may give rise to a stillborn cyclops. A variety of conditions will produce congenital hydrocephalus, and any condition that produces apparent hydrocephalus at birth may produce mental retardation. Correction of the hydrocephalus at or soon after birth reduces the probability of retardation as a direct effect of the hydrocephalus, but conditions that cause damage to the brain as well as obstruct the flow of CSF may leave the patient retarded. An uncorrected hydrocephalus may not be lethal for many years.

24
Q
  1. A 6-month-old child is noted to have head lag, tongue fasciculations, and bilateral abducens palsies. MRI scan reveals a type 2 Chiari malformation. Which of the following defects would this child be likely to have?
    a. A renal cyst
    b. Pulmonary atelectasis
    c. Spina bifida
    d. Holoprosencephaly
    e. A hepatic cyst
A

C

(Victor, pp 1064–1065.) Spina bifida may be extreme in some of the children affected by the Arnold-Chiari (type 2 Chiari) malformation. A myelomeningocele may be present at the level of the spina bifida. Spinal cord tissues may extend into this mass and lie just under the skin covering the neural tube defect. Children with obvious spinal defects usually have persistent problems with leg movements and bladder and bowel control.

25
Q

A 7-year-old boy is taken by his parents to see a dermatologist. They have noticed nodules on his face and are concerned. The dermatologist tells them that their child has adenoma sebaceum.

  1. Adenoma sebaceum of the face is especially common with which of the following diseases?
    a. Neurofibromatosis
    b. Sturge-Weber syndrome
    c. Tuberous sclerosis
    d. Ataxia telangiectasia
    e. Fragile X syndrome
A

C

(Victor, pp 1069–1073.) Adenoma sebaceum occurs in about 90% of patients with tuberous sclerosis. A depigmented lesion, called a shagreen patch, occurs in only about 20% of these patients. Adenoma sebaceum usually becomes apparent over the malar eminences of the face between 2 and 5 years of age and may evolve into difficult-to-treat angiofibromas of the skin. In ataxia telangiectasia, facial telangiectasias may develop. Sturge-Weber syndrome is characteristically associated with a portwine spot over part of the face. Patients with neurofibromatosis often have café au lait spots, but these do not usually occur on the face.

26
Q

A 7-year-old boy is taken by his parents to see a dermatologist. They have noticed nodules on his face and are concerned. The dermatologist tells them that their child has adenoma sebaceum.

  1. This disease is inherited in
    a. A sex-linked recessive pattern
    b. An autosomal dominant pattern
    c. An autosomal recessive pattern
    d. A pattern most consistent with newly arising mutations
    e. A pattern suggesting a mitochondrial gene defect
A

B

(Victor, pp 1069–1073.) Although the inheritance pattern of tuberous sclerosis is autosomal dominant, the penetrance is variable. A severely impaired child may be born to a negligibly affected parent. Despite the consensus that inheritance is autosomal dominant, estimates of spontaneous mutations in affected persons are as high as 70%.

27
Q

A 7-year-old boy is taken by his parents to see a dermatologist. They have noticed nodules on his face and are concerned. The dermatologist tells them that their child has adenoma sebaceum.

  1. Retinal problems with this disease
    a. Include retinal phakomas
    b. Include retinitis pigmentosa
    c. Include retinal telangiectasias
    d. Include retinoblastomas
    e. Are generally not part of the disease
A

A

(Victor, p 1071.) Retinal phakomas, which require no treatment, are a principal criterion for making the diagnosis of tuberous sclerosis. Along with adenoma sebaceum and periventricular tubers, they are virtually pathognomonic. Other findings that are typical of tuberous sclerosis include ash leaf spots, shagreen patches, CNS calcifications, renal tumors, cardiac rhabdomyomas, and seizure disorders.

28
Q

A 7-year-old boy is taken by his parents to see a dermatologist. They have noticed nodules on his face and are concerned. The dermatologist tells them that their child has adenoma sebaceum.

  1. Calcifications evident on the skull x-ray or CT scan of a patient with this disease usually represent
    a. Calcified subependymal glial nodules
    b. Calcified meningeal adhesions
    c. Meningeal psammoma bodies
    d. Calcified astrocytomas
    e. Calcified granulomas
A

A

(Victor, pp 1071–1073.) By 5 years of age, more than half of patients with tuberous sclerosis will have subependymal glial nodules that have calcified. These nodules usually do not become malignant, but they may enlarge sufficiently to produce an obstructive hydrocephalus. Ventriculoperitoneal shunting may be needed if obstruction develops.

29
Q
  1. A 50-year-old man complaining of dizziness is found to have a cyst occupying 50% of his posterior fossa and incomplete fusion of the cerebellar elements inferiorly. There is no evidence of an obstructive hydro-cephalus. His longevity can be estimated to be

a. Less than 3 months
b. Less than 1 year
c. Less than 5 years
d. Less than 10 years
e. Unaffected by this finding

A

E

(Greenberg, 2/e, pp 587–588.) That the cerebellar elements are not fused in the midline suggests an asymptomatic Dandy-Walker malformation. This congenital disorder of brain formation may become symptomatic soon after birth if an obstructive hydrocephalus develops as one facet of the anomaly. In the absence of an obstructive hydrocephalus, the patient may remain asymptomatic throughout life.

30
Q
  1. The treatment of choice for children with infantile spasms is
    a. Carbamazepine (Tegretol)
    b. Phenobarbital
    c. Phenytoin (Dilantin)
    d. Divalproex sodium (Depakote)
    e. Adrenocorticotropic hormone (ACTH)
A

E

(Rowland, p 815.) Adrenocorticotropic hormone is usually given as a gel intramuscularly to control infantile spasms in children with tuberous sclerosis; 40 to 80 mg is divided into two doses. Treatment continues until the infantile spasms abate or the EEG pattern of hypsarrhythmia resolves. This usually requires 6 to 8 weeks of treatment. The ACTH should not be stopped abruptly.

31
Q
  1. A 9-year-old boy has been generally healthy. However, his parents are concerned that his many areas of hyperpigmented skin may have some significance. They have been told that these are café au lait spots. Café au lait spots are commonly found on patients with
    a. Tuberous sclerosis
    b. Neurofibromatosis
    c. MS
    d. Sturge-Weber syndrome
    e. Ataxia telangiectasia
A

B

(Victor, pp 1073–1077.) Café au lait spots in patients with neurofibromatosis are usually larger than a few centimeters and occur in several locations in individual patients. Some have ragged edges and are called coast of Maine spots. They occur with both type 1 and type 2 neurofibromatosis, but are much more common with type 1.

32
Q
  1. The newborn infant with motor neuron disease is likely to exhibit
    a. Seizures
    b. Hypotonia
    c. Hypsarrhythmia
    d. Moro reflexes
    e. Spina bifida
A

B

(Swaiman, pp 1164–1169.) The child with congenital weakness, hypotonia, and muscle atrophy may have Werdnig-Hoffmann disease, a congenital motor neuron disease. This is an especially lethal form of motor neuron disease and may limit the child’s life expectancy to weeks or months. A similar pattern of disease that appears in older children is less lethal and is called Kugelberg-Welander disease. These types of motor neuron diseases are also known as spinal muscular atrophies (SMAs). Anterior horn cell disease is presumed to be a pivotal feature of diseases in this category.

33
Q
  1. Many children with Tay-Sachs disease develop blindness before they die, with retinal accumulation of gangliosides that produces
    a. Optic neuritis
    b. Cherry red spots
    c. Chorioretinitis
    d. Retinal detachments
    e. Waxy exudates
A

B

(Victor, pp 996–997.) More than 90% of children with Tay-Sachs disease develop cherry red spots on the retina. The red spot at the fovea develops as retinal ganglion cells become distended with glycolipid. There are no ganglion cell bodies overlying the fovea, and so the red color of the vascular choroid is apparent in this region but obscured by more opaque glycolipid-engorged cells over the remainder of the retina.

34
Q
  1. The parents of a 10-year-old boy bring their child in to see you. The child has been diagnosed with cerebral palsy, and the parents do not really understand what this means. As part of your explanation, you tell them that cerebral palsy is a static encephalopathy because
    a. Deficits do not appear after birth
    b. The injury to the brain does not progress
    c. Affected persons fail to reach any developmental milestones on time
    d. Affected persons have resting tremors
    e. The EEG exhibits a disorganized background rhythm
A

B

(Rowland, p 476.) A static encephalopathy is one in which brain damage has been arrested but neurologic problems persist. Establishing that the brain lesion is not progressive may require extensive testing. A young child with a static motor disorder is said to have CP. Neurodegenerative diseases with slow or stepwise progressions may appear to be static encephalopathies over the course of months, but prove to be progressive encephalopathies over the course of years. The brain lesion with CP is static, but the deficits associated with CP may evolve as the child matures.

35
Q
  1. A 6-year-old child is brought to the neurologist because of developmental delay. Her morphological features are typical and chromosome analysis confirms a diagnosis of Down syndrome (trisomy 21). The brain of this patient is expected to be
    a. Smaller than normal for age and body size
    b. Larger than normal for age and body size
    c. Abnormally long in anteroposterior measurements
    d. Hydrocephalic
    e. Excessively convoluted
A

A

(Victor, p 1067.) The brain of the patient with Down syndrome (trisomy 21) is typically foreshortened. The gyral pattern is simplified, and the frontal lobes are small. The occipital lobes may be slanted, and the overall shape of the skull is abnormal.

36
Q
  1. Porencephaly usually develops as a consequence of
    a. Fetal alcohol syndrome
    b. Vascular or other destructive injuries to the fetal brain
    c. Trisomy 13
    d. Trisomy 21
    e. Dandy-Walker syndrome
A

B

(Osborn, pp 52–56.) In utero damage to the fetal brain may be evident at birth as large cysts in the brain. The presence of one or more of these intracerebral cysts is called porencephaly. Some pathologists believe that schizencephaly, a related abnormality in which brain segmentation is abnormal, is caused by similar phenomena, which include incidents such as strokes and viral encephalitides in the fetal brain.

37
Q
  1. What percentage of patients with tuberous sclerosis have mental retardation?
    a. 1
    b. 10
    c. 25
    d. 65
    e. 99
A

D

(Swaiman, p 534.) Of the 65% of patients with tuberous sclerosis who are retarded, half are severely retarded. Seizures are invariably associated with retardation. About 20% of patients with tuberous sclerosis develop the Lennox-Gastaut syndrome with persistent seizures and significant mental retardation. These children usually have a mixed seizure disorder, whereas those without Lennox-Gastaut syndrome most often have complex partial seizures.

38
Q
  1. A child is born to a 19-year-old woman who has had two to eight drinks per day throughout her pregnancy. What is the major pathologic effect of alcohol on the central nervous system of the developing fetus?
    a. Cerebral ischemia
    b. Periventricular hemorrhage
    c. Macrocephaly
    d. Impaired neuronal migration
    e. Holoprosencephaly
A

D

(Victor, pp 1247–1248.) Alcohol abuse in pregnant women is associated with three major kinds of abnormalities in the developing fetus: intrauterine and postpartum growth retardation, dysmorphic facies in the newborn, and effects on the development of the CNS. The broad range of neurologic and systemic abnormalities observed in children born to alcohol-abusing women is referred to as the fetal alcohol syndrome. Alcohol is teratogenic at high doses and may interfere measurably in fetal development with exposure at any dose. Although the mechanism of alcohol’s effect on the developing brain is not entirely clear, it appears that alcohol acts primarily to impair neuronal migration. This may result in formation of heterotopias (collections of cortical neurons in abnormal locations), cortical disorganization, and malformations of the cerebellum and brainstem. Mental retardation, learning disabilities, hyperactivity, and microcephaly, not macrocephaly, are the common clinical neurologic consequences of fetal alcohol syndrome. Ischemia and hemorrhagic complications are not part of the syndrome. Holoprosencephaly refers to a failure of the two sides of the frontal cerebrum to separate properly, leading to a fusion of the frontal poles and hippocampi with no interhemispheric fissure.

39
Q
  1. A 37-year-old man has an MRI performed by his primary care doctor because of a long history of headaches. It is notable only for the finding of a type 1 Chiari malformation. He is sent to a neurologist for further evaluation. A type 1 Chiari malformation usually becomes symptomatic as which of the following in adults?
    a. Epilepsy
    b. Hydrocephalus
    c. Ataxia
    d. Dementia
    e. Psychosis
A

C

(Osborn, pp 15–18.) Both type 1 and type 2 Chiari malformations are primarily abnormalities of hindbrain development. With the type 1, or adult, abnormality, the cerebellar tonsils extend below the foramen magnum. Affected persons do not usually become symptomatic until they are adults, and then the symptoms are largely referable to the cerebellum. With the type 2 malformation, cerebellar anatomy is usually much more deranged, and the cerebellar vermis lies well below the foramen magnum. Type 2 malformations most often become symptomatic at birth or during infancy and may produce hydrocephalus with retardation.

40
Q
  1. A 25-year-old mother develops an illness during pregnancy. A diagnosis of cytomegalovirus (CMV) infection is made by serology. Prenatal CMV infections may produce which retinal disturbance?
    a. Chorioretinitis
    b. Cherry red spot
    c. Microaneurysms
    d. Hypervascularity
    e. Hemorrhage
A

A

(Victor, p 1071.) Microaneurysms and hypervascularity are typically seen with diabetic retinopathy rather than developmental disease. Hemorrhages in the retina would be more typical of hypertensive encephalopathy or a coagulopathy. Neurologic problems that develop in the infant with a prenatal CMV infection include retardation, microcephaly, seizures, and hearing deficits. The virus often causes chorioretinitis, optic atrophy, and architectural changes throughout the brain.

41
Q
A