NEET 2014 Anatomy MCQ

A 42-year-old male was admitted to the hospital after a head-on vehicular collision in which he received severe blunt trauma to his sternum from the steering wheel. What part of the heart would be most likely to be injured by the impact?

• Right ventricle
• Apex of left ventricle
• Left ventricle
• Right atrium
• Anterior margin of the left atrium

These components of the heart are readily viewed in a plain radiograph of the thorax. It is important to understand the spatial arrangement of the heart as it rests in the thorax. The conus region of the right ventricle is located on the most anterior aspect of the heart, thus it is the most anterior portion of the heart within the thorax. The apex of the left ventricle is also located anteriorly, but it is located lateral to the sternum and occupies little area compared with the right ventricle. The left ventricle is positioned on the left lateral side and slightly posterior position in the thorax. The right atrium is located on the right lateral side of the heart. The anterior margin of the left atrium is positioned posteriorly in the thorax.

NEET 2014 Anatomy MCQ

A 79-year-old male retired military veteran presents to the outpatient clinic with an abnormal curvature of the vertebral column. He complains that it has become increasingly painful to walk around town. Upon physical examination he has an abnormally increased thoracic curvature resulting from osteoporosis. Which of the following is the most likely clinical condition of this patient’s spine?

• Scoliosis
• Kyphosis
• Spinal stenosis
• Lordosis
• Herniated disk

Scoliosis is defined as a lateral deviation of the spinal column to either side. Kyphosis is an increased primary curvature of the spinal column. This curvature is associated with thoracic and sacral regions and is most likely this patient’s clinical condition. Spinal stenosis is a narrowing of the vertebral canal and is not directly associated with a displacement of the spinal column. Lordosis is the increased secondary curvature affecting the cervical and lumbar regions. A herniated disk is a rupture of the anulus fibrosus of the intervertebral disk, commonly causing a posterolateral displacement of the nucleus pulposus into the vertebral canal.

Common causes of leukocoria in children

The common causes of leukocoria in children include.

Retinoblastoma (47 percent of cases in one series)

Persistent fetal vasculature

Retinopathy of prematurity

Cataract

Coloboma (fissure or cleft) of choroid or optic disc

Uveitis

Toxocariasis

Coats disease

Vitreous hemorrhage

Retinal dysplasia

Retinoblastoma  — Retinoblastoma is the most common intraocular tumor of childhood, occurring in approximately 1 in 15,000 live births .The annual incidence is 11 per million in children from birth to four years of age and 0.6 per million in children five years and older .The average age at the time of diagnosis is two years in unilateral cases and one year in bilateral cases

Leukocoria is the most common presenting finding . Other findings may include strabismus, decreased vision, ocular inflammation, family history of retinoblastoma, vitreous hemorrhage, hyphema, orbital cellulitis, proptosis, glaucoma, eye pain, and fever . The diagnosis of retinoblastoma is usually made on the basis of clinical examination and the presence of calcification on computed tomography (CT) or ocular ultrasonography.

Persistent fetal vasculature  — Persistent fetal vasculature (PFV, formerly called persistent hyperplastic primary vitreous [PHPV]) results from a failure of the embryonic primary vitreous and hyaloid vascular system to involute during gestation. The posterior form is characterized by the presence of a rudimentary vascular stalk in the vitreous that usually extends to the optic nerve and is associated with a plaque-like opacity in the posterior lens. It is typically unilateral; bilateral lesions may be associated with trisomy 13. The involved eye is usually mildly microphthalmic with a shallow anterior chamber, prominent vessels on the iris, elongated ciliary processes, and vascularized white retrolental tissue.Children with PFV may go on to develop glaucoma, cataract, intraocular hemorrhage, or retinal detachment

Retinopathy of prematurity  — Retinopathy of prematurity (ROP) is a developmental vascular proliferative disorder that occurs in the incompletely vascularized retina of premature infants and can lead to retinal detachment. ROP affects a substantial number of premature infants, and its incidence increases with decreasing gestational age and birth weight. Other risk factors for ROP include assisted ventilation for longer than one week, surfactant therapy, high blood transfusion volume, sepsis, fluctuations in blood gas measurements, intraventricular hemorrhage, bronchopulmonary dysplasia, and elevated arterial oxygen tension ROP causes leukocoria only when ROP is severe and results in retinal detachment.

Cataract  — A cataract is an opacity of the lens of the eye that can cause partial or total blindness if not diagnosed and treated promptly. Congenital cataracts may be present at birth or appear in early infancy .

Autosomal dominant inheritance is the most commonly identified cause of cataracts in children. Cataracts may be associated with congenital infections (eg, rubella, toxoplasmosis, herpes simplex virus, cytomegalovirus [CMV]). Cataracts also can develop in children who have various systemic, genetic, or metabolic conditions (eg, diabetes mellitus, Turner syndrome, Down syndrome, galactosemia, peroxisomal disorders) or who are exposed to high-dose, long-term systemic corticosteroid therapy . In addition, cataracts may develop in children who have uveitis or sustain ocular trauma.

Optic disc abnormalities  — Congenital and acquired abnormalities of the optic disc, such as optic disc coloboma , morning glory disc ( picture 5), myelinated nerve fibers and malignant infiltration also can produce leukocoria. These disorders are discussed separately.

Uveitis  — Inflammation of the iris, ciliary body, and/or choroid can cause leukocoria due to abnormal retinal reflection, the presence of inflammatory cells and debris in the vitreous, or the development of secondary cataract . Uveitis is an occasional cause of leukocoria in patients with inflammatory or infectious retinal diseases such as toxocariasis, toxoplasmosis, or CMV retinitis. A more common mechanism is the abnormal white or off-white reflection of the lesion itself (eg, toxocariasis).

Toxocariasis  — Toxocariasis, or visceral larva migrans, is an infection caused by the dog ascarid 

Toxocara canis or, less commonly, the cat ascaridToxocara catis . It occurs most commonly in children one to five years of age. Ocular involvement may be the sole manifestation of disease, often presenting in those without an antecedent history of symptomatic visceral larva migrans. The ocular lesion is caused by the inflammatory response to the second-stage larva, which may localize in the eye. Two characteristic lesions may result:

A whitish subretinal granuloma measuring one to two disc diameters and located anywhere in the retina; this lesion can cause leukocoria even in the absence of significant uveitis

A large inflammatory mass (nematode endophthalmitis) with prominent vitreous inflammation

Either of these lesions may be confused with retinoblastoma, particularly if there is associated calcification. Common presenting signs are strabismus and poor vision.

Coats disease  — Coats disease is characterized by idiopathic retinal telangiectasias and retinal exudation that can cause retinal detachment . It is usually unilateral and has a bimodal distribution, primarily affecting males less than 18 years of age and middle-aged men . Presenting complaints include decreased visual acuity, strabismus, or leukocoria. Coats disease appears to be caused by somatic mutation in the NDP gene, resulting in a deficiency of norrin (the protein product of the NDP gene) within the developing retina .

Vitreous hemorrhage  — Vitreous hemorrhage causes leukocoria when there is extensive organization of the blood into a clot before degradation . Vitreous hemorrhage can occur in a number of conditions, including :

Hemorrhagic disease of the newborn

Advanced ROP

Persistent fetal vasculature

Trauma

Leukemia or other blood dyscrasias

Trauma, including intentional trauma (eg, nonaccidental head injury) is the most common cause of vitreous hemorrhage in young children. In the appropriate clinical context, vitreous hemorrhage may be diagnostic of nonaccidental injury.

Retinal dysplasia  — Retinal dysplasia refers to the abnormal development of retinal tissue or cells with retention of some features resembling normal structures. It implies aberrant differentiation in any of the cellular layers and is often associated with the formation of rosettes of circular or oval groupings of dysplastic retinal cells. The rosettes are highly variable in shape and size (unlike those in retinoblastoma, which are uniform in size). In many cases, retinal dysplasia is associated with retinal detachment .

Retinal dysplasia may be caused by intrauterine insults or infection. In addition, it occurs in some genetic diseases such as trisomy 13, trisomy 18, and Norrie disease. Norrie disease is an X-linked disorder associated with microcephaly, congenital blindness, deafness, and progressive neuropsychiatric illness.Ocular findings include bilateral retinal detachment without anterior segment abnormalities, features that help to distinguish it from PFV or cataract .

ELECTROENCEPHALOGRAM (EEG)

ELECTROENCEPHALOGRAM (EEG)
Normal and Abnormal
Invented in the first half of the twentieth century by a psychiatrist (Hans Berger) and improved by computerization and correlation with patient videos, the EEG remains the most specific laboratory test for seizures. In addition, it still helps in the diagnosis of several other neurologic conditions. Neurologists liberally order an EEG as a painless, harmless, relatively inexpensive, and, when positive, helpful diagnostic test. The routine EEG records cerebral electrical activity detected by “surface” or “scalp” electrodes- Four frequency bands of cerebral activity, represented by Greek letters, emanate from the brain EEG readers first ascertain the patient’s age and level of consciousness. They also determine the display of the electrodes (the montage) and note the time scale, which is determined by vertical lines on the EEG paper or displayed as 1-second horizontal bars.

Although approaches vary, most readers then determine the EEG’s background or dominant rhythm (see later), organization, and symmetry. EEG readers accord special attention to unusually pointed single discharges, called sharp waves or spikes, and abnormal patterns, especially if they occur in paroxysms. They judge all these features in relation to whether the patient is awake, asleep, unresponsive, or having observable seizure activity. The normal background rhythm in an awake adult consists of waves of activity in the alpha range of 8–13 cycles per second (Hertz [Hz]) detectable mostly over the occipital region

Neurologists refer to this pattern as the posterior dominant rhythm. It is prominent when individuals are relaxed with their eyes closed, but disappears if they open their eyes, concentrate, or are apprehensive. When people undergoing an EEG merely fix their gaze on a clock or add two single-digit numbers,
faster rhythms replace alpha activity. Preoccupations, concerns, or anxiety eliminate alpha activity. Because alpha activity reflects an anxiety-free state, it represents an important parameter in “alpha training,” biofeedback, and other behavior modification techniques. Alpha activity also disappears when people fall asleep or take psychotropic medicines.

In the elderly, the background rhythm typically slows but remains within or just below the alpha range. In the early stages of Alzheimer disease, the background activity is also slower than normal. In the more advanced stages of Alzheimer disease,as well as in many other neurologic illnesses, the background EEG activity not only slows well below the alpha range, but also loses its organization. Beta activity consists of high (> 13 Hz)-frequency, lowvoltage activity located maximally overlying the frontal region. It replaces alpha activity when people concentrate, become anxious, or take many hypnotics or sedatives, including benzodiazepines. Beta activity usually inserts itself into the background EEG activity of most adults.

Theta (4–7 Hz) and delta (< 4 Hz) activities occur normally in children and everyone during deep sleep, but are usually absent in healthy alert adults. When present over the entire brain, theta or delta activity in wakefulness often indicates a neurodegenerative illness, such as Alzheimer disease, or a metabolic derangement. Continuous focal slow activity with phase reversal in bipolar montages sometimes originates in an underlying cerebral lesion; however, the absence of theta or delta activity certainly does not exclude one. Spikes, sharp waves, and slowing – nonspecific changes – occur in about 3–15% of the general, healthy population. When they are isolated and asymptomatic, these anomalies have no clinical significance and require no further investigation. However, when spikes and sharp waves are repetitive and phase-reversed, they are an indication of an irritative cerebral focus with potential to
produce seizures. Moreover, paroxysms of them suggest the diagnosis.

NEET 2014 MCQ NEUROLOGY / ANATOMY

A 47-year-old man complained to his physician that he had recently begun to experience some difficulty in maintaining his balance while attempting to walk and loss of ability to recognize objects placed in his hand when his eyes were closed. His internist referred him to a local neurology clinic where a battery of tests revealed the presence of a growing tumor. The tumor was most likely affecting the:

• Anterior spinocerebellar tract
• Posterior spinocerebellar tract
• Dorsolateral tract of Lissauer
• Dorsal columns
• Neospinothalamic tract

The dorsal columns of the spinal cord contain the fasciculus gracilis and fasciculus cuneatus. Patients with lesions in the dorsal columns have loss of kinesthetic sensation and, thus, are unable to identify the position of their limbs in space when their eyes are closed, and these patients also do not know if one of their joints is in flexion or extension. In addition, they cannot identify the shape, size, or texture of objects in their hands by means of touch (astereognosis). These patients are unable to perceive vibration when it is applied to their bodies and, therefore, cannot maintain steady posture when their eyes are closed. The posterior and anterior spinocerebellar tracts are involved in nonconscious sensation of limb proprioception. The lateral neospinothalamic tract and dorsolateral tract of Lissauer are involved in mediating pain sensation.

NEET 2014 MCQ Psychiatry

Which two statements regarding the relationship of interictal violence to epilepsy are true?

• Violence is associated with epilepsy patients taking two or more AEDs.
• Violence tends to occur in schizophrenic or mentally retarded epilepsy patients, but rarely in other epilepsy patients.
• Crimes of adult epileptic incarcerated criminals are no more violent than those of nonepileptic ones.
• The prevalence of epilepsy is no greater in prisoners than in the general population.

NEET 2014 CNS MCQ

Temporal arteritis is best treated initially with:

• Cyclophosphamide
• Prednisone, 20 mg/day
• Prednisone, 80 mg/day
• Nonsteroidal anti-inflammatory agents
• Carbamazepine

The best initial treatment for biopsy-proven temporal arteritis is high-dose prednisone. Failure to treat can result in blindness secondary to occlusion of the retinal arteries.