-
Question 1
Correct
-
A patient presents with loss of fine touch and sense of proprioception in the lower part of the body (below T6). He is likely to have a lesion involving:
Your Answer: Gracile nucleus
Explanation:The gracile nucleus is located in the medulla oblongata and is one of the dorsal column nuclei involved in the sensation of fine touch and proprioception. It contains second-order neurons of the dorsal column–medial lemniscus system, that receive inputs from sensory neurones of the dorsal root ganglia and send axons that synapse in the thalamus.
The gracile nucleus and fasciculus carry epicritic, kinaesthetic and conscious proprioceptive information from the lower part of the body (below the level of T6 in the spinal cord). Similar information from the upper part of body (above T6, except for face and ear) is carried by the cuneate nucleus and fasciculus. The information from face and ear is carried by the primary sensory trigeminal nucleus.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 2
Correct
-
Thalamic syndrome will most likely result in:
Your Answer: Hyperaesthesia
Explanation:Signs and symptoms of thalamic syndrome include contralateral hemi anaesthesia, burning or aching sensation in one half of a body (hyperaesthesia), often accompanied by mood swings.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 3
Correct
-
A 70-year-old man who was previously healthy develops a rapidly progressing neurological deficit. A MRI reveals a large, poorly defined mass with central necrosis in his left temporal lobe. What is the most likely diagnosis?
Your Answer: Glioblastoma multiforme
Explanation:Glioblastoma multiforme, or grade 4 astrocytoma, is the most common and aggressive primary brain tumour. They are formed by small areas of necrotising tissue surrounded by highly anaplastic cells. Most of them arise from the deep white matter of the brain and quickly infiltrate it, becoming very large before they are symptomatic. The most common symptom is progressive memory, personality or neurological deficit due to temporal and frontal lobe involvement. It is most common in men, and risk factors include: neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Turcot syndrome.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 4
Correct
-
Which of these infectious agents tends to affect people under 20 and over 40 years old, can cause acute encephalitis with cerebral oedema and petechial haemorrhages, along with haemorrhagic lesions of the temporal lobe. A lumbar puncture will reveal clear cerebrospinal fluid with an elevated lymphocyte count?
Your Answer: Herpes simplex virus
Explanation:Haemorrhagic lesions of the temporal lobe are typical of Herpes simplex encephalitis (HSE). It tends to affect patients aged under 20 or over 40 years, and is often fatal if left untreated. In acute encephalitis, cerebral oedema and petechial haemorrhages occur and direct viral invasion of the brain usually damages neurones. The majority of cases of herpes encephalitis are caused by herpes simplex virus-1 (HSV-1), and about 10% of cases of herpes encephalitis are due to HSV-2, which is typically spread through sexual contact.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 5
Correct
-
If a 55-year old gentleman who has suffered a stroke, develops a tremor in his fingers that worsens on reaching for an object, what part of his brain is likely to be involved?
Your Answer: Cerebellum
Explanation:The cerebellum plays an important role in the integration of sensory perception and motor output. Multiple neural pathways link the cerebellum with the motor cortex and the spinocerebellar tract. The cerebellum uses the constant feedback on body position to fine-tune the movements and integrates these pathways. The patient described here has a characteristic cerebellar tremor that is a slow, broad tremor of the extremities and occurs at the end of a purposeful movement.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 6
Correct
-
A lesion involving the lateral geniculate nucleus of the thalamus is likely to affect:
Your Answer: Vision
Explanation:The lateral geniculate nucleus (LGN) of the thalamus is the primary processor of visual information in the central nervous system. The LGN receives information directly from the retina and sends projections directly to the primary visual cortex. The LGN likely helps the visual system focus its attention on the most important information.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 7
Correct
-
In which of the following compartments of the femoral sheath is the femoral artery located?
Your Answer: Lateral compartment
Explanation:The femoral sheath also known as the crural sheath is made up of three compartments; lateral, intermediate and the medial. The femoral artery is contained in the lateral compartment of the femoral sheath while the femoral vein is in the intermediate compartment.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 8
Correct
-
During an OSCE exam a medical student is asked to locate the sternal angle. The sternal angle is a land mark for locating the level of the:
Your Answer: Second costal cartilage
Explanation:The sternal angle, a key landmark used in the clinic for auscultating for heart sounds, is the point of attachment of the costal cartilage of rib 2 to the sternum. It thus corresponds to the location of the second rib. A horizontal plane through the sternal angle traverses the T4/T5 intervertebral disc and marks the inferior boundary of the superior mediastinum.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 9
Correct
-
A patient with a long standing lower motor neuron lesion will have:
Your Answer: Muscle wasting
Explanation:Lower motor neurons (LMNs) connect the brainstem and spinal cord to muscle fibres. Damage to lower motor neurons is indicated by abnormal electromyographic potentials, fasciculations, paralysis, weakening and wasting of skeletal muscles.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 10
Incorrect
-
A patient presents with loss of pain and temperature sensation in the left leg. He is likely to have a lesion involving:
Your Answer: Right anterior spinothalamic tract
Correct Answer: Right lateral spinothalamic tract
Explanation:The spinothalamic tract is a sensory pathway originating in the spinal cord that transmits information to the thalamus. There are two main parts of the spinothalamic tract: the lateral spinothalamic tract transmits pain and temperature and the anterior spinothalamic tract transmits touch (crude touch). The decussation of this pathway occurs at the level of the spinal cord. Hence, a unilateral lesion of the lateral spinothalamic tract causes contralateral loss of pain and temperature.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 11
Correct
-
A neurotransmitter of the nigrostriatal pathway is:
Your Answer: Dopamine
Explanation:Dopamine acts as a neurotransmitter in the brain, activating dopamine receptors. It is also a neurohormone released from the hypothalamus. It plays an important role in the reward system. It is believed that dopamine provides a teaching signal to parts of the brain responsible for acquiring new motor sequences (behaviours), by activation of dopamine neurons when an unexpected reward is presented. Loss of dopamine neurones in the nigrostriatal pathway causes Parkinson’s disease. In the frontal lobes, dopamine controls the flow of information from other areas of the brain, and thus, dopamine disorders in this region can cause a decline in neurocognitive functions, especially memory, attention and problem solving. Reduced dopamine concentrations in the prefrontal cortex are thought to contribute to attention-deficit disorder and some symptoms of schizophrenia. Dopamine is also the primary neuroendocrine regulator of the secretion of prolactin from the anterior pituitary gland. Dopamine is also commonly associated with the pleasure system of the brain. This plays a key role in understanding the mechanism of action of drugs (such as cocaine and the amphetamines), which seem to be directly or indirectly related to the increase of dopamine.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 12
Incorrect
-
A previously healthy 40-year-old housewife suddenly complains of a headache and loses consciousness. A CT scan reveals subarachnoid haemorrhage. Which of the following is the most probable cause?
Your Answer: Epidural haematoma
Correct Answer: Ruptured berry aneurysm
Explanation:Saccular aneurysms, also known as berry aneurysms, appear as a round outpouching and are the most common form of cerebral aneurysm. They are a congenital intracranial defect, and haemorrhage can occur at any age, but is most common between the ages of 40-65 years. A second rupture (rebleeding) sometimes occurs, most often within about 7 days of the first bleed.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 13
Correct
-
A 32-year old gentleman came to the emergency department, complaining of progressively increasing weakness in his arms and legs over 5 days. On examination, there is symmetrical weakness on both sides of his face, along with weakness of the proximal and distal muscles of all four limbs. No loss of sensation noted. Deep tendon reflexes could not be elicited and plantar responses were downward. On enquiry, it was revealed that he had an upper respiratory tract infection 10 days ago. The likely diagnosis is:
Your Answer: Guillain–Barré syndrome
Explanation:Guillain–Barré syndrome (GBS) is an acute, autoimmune polyradiculoneuropathy which affects the peripheral nervous system and is usually triggered by an acute infectious process. 75% patients have a history of acute infection within the past 1–4 weeks, usually respiratory or gastrointestinal. immunisations have also been implicated. The most common form is acute inflammatory demyelinating polyneuropathy. It results in an ascending paralysis with complete loss of deep tendon reflexes. Treatment includes immunoglobulins and supportive care. However, the disease may be fatal due to severe pulmonary complications and dysautonomia.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 14
Incorrect
-
A 40-year old woman with portal hypertension has impaired venous drainage of the anal canal above the pectinate line. Thus, there might be an increase in blood flow downward to the systemic venous system via anastomoses with the inferior rectal vein. This is a tributary of?
Your Answer: Inferior mesenteric vein
Correct Answer: Internal pudendal vein
Explanation:The inferior rectal vein drains into the internal pudendal vein. In addition the external iliac vein is one of the two branches of the common iliac vein however the internal iliac vein and it’s tributaries (including the pudendal vein) are much more important in draining the pelvic structures.
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 15
Correct
-
Destruction of the ventromedial nucleus of the hypothalamus will result in:
Your Answer: Loss of satiety
Explanation:The ventromedial nucleus of the hypothalamus is divided into an anterior and a superior part. The anterior part controls the female sexual drive, whereas the superior part is responsible for satiety. Destruction of the superior part of the nucleus will result in overeating, as no signal tells the body that it is satisfied.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 16
Correct
-
An ultrasound report of a 35-year old female patient revealed that she had cancer of the pancreas and presented with subsequent severe obstructive jaundice. In which part of this was woman's pancreas was the tumour most likely located?
Your Answer: Head
Explanation:The pancreas is divided into five parts; the head, body, neck, tail, and the uncinate process. Of the five parts, tumours located at the head of the pancreas in most instances cause obstruction of the common bile duct more often than tumours in the other parts of the pancreas. This is because the common bile duct passes through the head of the pancreas from the gallbladder and the liver (it is formed where the cystic and the hepatic bile duct join) to empty bile into the duodenum. This biliary obstruction leads to accumulation of bile in the liver and a consequent bilirubinaemia (raised levels of blood bilirubin). This results in jaundice. The pancreas is not divided into lobes.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 17
Correct
-
A 25-year-old football player suffers severe head trauma during a game. Physical examination reveals a decerebrate posture and bilateral papilledema. A CT scan reveals marked diffuse cerebral oedema. This condition will be most severe in which component of the brain?
Your Answer: White matter
Explanation:The greatest amount of salt and water increase with cerebral oedema occurs within the white matter. Any swelling from oedema, haemorrhage or haematoma increases the intracranial pressure (ICP). As the ICP increases, the cerebral perfusion decreases and brain tissue can become ischaemic, even leading to brain death.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 18
Correct
-
Which of the following is true about myasthenia gravis?
Your Answer: Response of skeletal muscle to nerve stimulation is weakened
Explanation:An autoimmune disorder, myasthenia gravis leads to progressive muscle weakness. It occurs due to formation of antibodies against the nicotinic acetylcholine (ACh) receptor of the motor endplate, which leads to impaired neuromuscular transmission. Thus, nerve stimulation will lead to a weakened muscle response, but direct electrical stimulation will bring about a normal response. Diagnostic test includes improvement of muscle weakness by small doses of acetylcholinesterase inhibitors (physostigmine or edrophonium). However, a large dose of physostigmine worsens the weakness due to desensitisation of the endplate to persistent Ach. One of the investigative tools includes radiolabelled snake venom α-bungarotoxin. It is an in vitro study performed on muscle biopsy specimens and used to quantify the number of ACh receptors at the motor endplate.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 19
Correct
-
In which situation is a stretch reflex such as knee jerk likely to be exaggerated?
Your Answer: In upper motor neuron lesion
Explanation:A stretch reflex is a monosynaptic reflex that causes muscle contraction in response to stretching within that muscle. The sensory apparatus in a muscle that are sensitive to stretch are the muscle spindles. The patellar (knee jerk) reflex is an example. In upper motor neuron lesions, the stretch reflexes tend to be brisk due to loss of inhibitory signals on gamma neurons through the lateral reticulospinal tract.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 20
Incorrect
-
Following an accident, a man was unable to extend the wrist and metacarpophalangeal joints, despite sensation being intact. Which nerve was likely damaged?
Your Answer: Median nerve
Correct Answer: Posterior interosseous nerve
Explanation:The posterior interosseous nerve which causes, what is known as the posterior interosseous nerve syndrome. The nerve is compressed before it bifurcates to form the medial and lateral branches. The compression is beyond the origin of the branches to the radial wrist extensors and the radial sensory nerve. The result of such a case is paralysis of the digital extensors and the extensor carpi ulnaris, resulting in dorsoradial deviation of the wrist.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
SESSION STATS - PERFORMANCE PER SPECIALTY
