If the following events were placed in chronological order which would come fourth? A. Cingulate gyrus herniates beneath falx cerebri. B. Frontal lobe tumour in right hemisphere. C. Interventricular septum shifts to left of midline. D. Medial temporal lobe herniates through tentorial opening. E. Pontine and midbrain haemorrhage. The answer is D. A tumour in the right frontal lobe (B) will act as a space occupying lesion resulting in raised intracranial pressure; expansion of the right hemisphere causes shift of the midline (C), the cingulate gyrus herniates beneath the falx (A); increasing expansion results in a tentorial hernia (D) and eventually fatal pontine and midbrain haemorrhage (E) supervene. 49
For each of the types of haematoma listed on the left select the most appropriate association from the list on the right. a. Acute subdural haematoma. b. Chronic subdural haematoma. c. Extradural haematoma. A. Associated with cerebral contusions and lacerations in many cases. B. Due to rupture of an aneurysm. C. May present weeks after trivial injury. D. Scarring of frontal poles. E. Usually due to a tear of the middle meningeal artery. The answer is A, C, E. This is a common finding if death occurs soon after a head injury which causes severe damage to cerebral tissue. Trivial injury (particularly in the elderly) may result in slow haemorrhage from the bridging veins which produces a slowly expanding haematoma. Fracture of the skull, particularly the temporal bone, may result in tearing of a meningeal vessel; classically there is a lucid interval followed by headache, drowsiness and coma. Rupture of an aneurysm (B) usually produces a subarachnoid haemorrhage. Scarring (D) is a sign of previous head injury.
Which ONE of the following is not a common site of hypertensive intracerebral haemorrhage? A. Basal ganglia. B. Cerebellum. C. Internal capsule. D. Occipital poles. E. Pons. The answer is D. Hypertensive intracerebral haemorrhage usually results from a rupture of a microaneurysm on a perforating cerebral artery; the commonest sites are basal ganglia (A), internal capsule (C), pons (E) and cerebellum (B).
Which ONE of the following is not a common site of a berry aneurysm? A. Basilar artery. B. Bifurcation of the middle cerebral artery. C. Junction of anterior communicating artery and anterior cerebral artery. D. Junction of internal carotid artery and posterior communicating artery. E. Vertebral artery. 50 The answer is E. Congenital or berry aneurysms are due to a defect in the medial coat at sites of bifurcation of the intracerebral arteries; the commonest sites are middle cerebral bifurcation (B), anterior communicator and anterior cerebral (C), internal carotid and posterior communicator (D) and on basilar artery (A). The aneurysms are often multiple.
If the following events were placed in chronological order which would come fourth? A. Abscess in temporal lobe. B. Chronic otitis media. C. Inadequate antibiotic therapy. D. Invasion of venous channels by bacteria. E. Osteitis of the tegmen tympani. The answer is D. Chronic otitis media (B) inadequately treated (C) may result in inflammation of the surrounding bone (E); this allows invasion of the venous channels by bacteria (D) which gain access to the brain itself, producing an abscess (A).
For each of the types of virus infection listed on the left select the most appropriate association from the list on the right. a. Cytomegalovirus. b. Herpes simples virus. c. Type 1 poliomyelitis virus. A. Anterior horn motor cells. B. Bilateral temporal lobe necrosis. C. Gasserian ganglion affected. D. Inclusion body in Purkinje cell cytoplasm. E. Nuclear inclusion bodies found in periventricular cells. The answer is E, B, A. Cytomegalovirus infection of the CNS is usually acquired in utero and is characterized by intranuclear inclusion bodies. Herpes simplex infection of the CNS gives bilateral temporal lobe necrosis (acute necrotizing encephalitis). Poliomyelitis affects the motor cells of the anterior horns of the spinal cord. The Gasserian ganglion is a common site of infection by Zoster (varicella) virus (C). Inclusion bodies in the cytoplasm of the Purkinje cells of the cerebellum (D) is a diagnostic feature of rabies (Negri bodies).
For each of the conditions listed on the left select the most appropriate association from the list on the right. a. Acute disseminated perivenous encephalomyelitis. 51 b. Acute haemorrhagic leukoencephalitis. c. Multiple sclerosis. A. Complication of septic shock. B. Complication of smallpox vaccination. C. Experimental model for demyelinating diseases. D. Familial disease due to enzyme deficiency. E. Unilateral optic neuritis an early symptom. The answer is B, A, E. This condition follows viral infections such as measles, rubella and may complicate smallpox vaccination. This condition may follow virus infections or may complicate septic shock. An early symptom in the relapsing course of multiple sclerosis may be optic neuritis. Experimental allergic encephalomyelitis (EAE) is an experimental model for demyelinating diseases (C). There are several familial diseases due to enzyme deficiencies which cause abnormalities of myelination (D); metachromatic leukodystrophy is a deficiency of arylsulphatase.
For each of the conditions listed on the left select the most appropriate association from the list on the right. a. Amyotrophic lateral sclerosis. b. Progressive bulbar palsy. c. Progressive muscular atrophy. A. Damage to lower motor neurones in spinal cord. B. Damage to lower motor neurones in medulla. C. Damage to motor and sensory tracts. D. Impaired blood flow in anterior spinal artery. E. Upper and lower motor neurone damage. The answer is E, B, A. This variant of motor neurone diseases involves degeneration of both upper and lower motor neurones. In bulbar palsy the lower motor neurones of the medulla are affected. In progressive muscular atrophy the spinal cord and lower motor neurones are affected. Damage to motor and sensory tracts is a feature of Friedreich’s ataxia (C). Acute myelitis may be caused by vascular insufficiency in the spinal cord (D).
Which ONE of the following is the commonest intracerebral neoplasm? 52 A. Astrocytoma. B. Ependymoma. C. Meningioma. D. Oligodendroglioma. E. Secondary carcinoma. The answer is E. The commonest intracerebral neoplasms are secondaries. Astrocytoma (A) is the commonest type of glioma. Ependymoma (B) is found in children. Meningioma (C) originates from the arachnoid granulations and presses into the brain tissue from outside.
Which ONE of the following forms a cystic tumour mass in the cerebellum in children? A. Astrocytoma. B. Ependymoma. C. Glioblastoma multiforme. D. Haemangioblastoma. E. Medulloblastoma. The answer is A. Cerebellar astrocytomas in children are usually cystic. Glioblastoma multiforme (C) is an anaplastic astrocytoma which occurs in the cerebral hemisphere of adults. Medulloblastoma (E) is derived from nerve cells and occurs in the cerebellum of children; it is not usually cystic. Haemangioblastoma (D) is a tumour of blood vessels and occurs usually in the cerebellum.