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Iraqi Board Neurosurgery study materials
Iraqi Board Neurosurgery study resources

Iraqi Board Neurosurgery practice questions

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Question 1Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

A lesion of the left optic tract produces which visual field defect?

  1. Right homonymous hemianopia Correct answer.
  2. Binasal hemianopia
  3. Bitemporal hemianopia
  4. Left homonymous hemianopia

Explanation

Each optic tract carries fibers from the temporal retina of the ipsilateral eye and the nasal retina of the contralateral eye, so it represents the contralateral visual field. A left tract lesion therefore abolishes the right half of both visual fields. Chiasmal lesions instead produce bitemporal defects.

Question 2Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Cerebrospinal fluid is produced mainly by which structure?

  1. Ependymal cells of the third ventricle floor
  2. Tela choroidea of the fourth ventricle
  3. Choroid plexus Correct answer.
  4. Arachnoid granulations

Explanation

The choroid plexus of the lateral, third, and fourth ventricles secretes the majority of CSF through active transport and filtration. Arachnoid granulations absorb CSF rather than produce it. Ependymal and tela choroidea contribute only small amounts.

Question 3Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

The primary motor cortex is located in which gyrus?

  1. Cingulate gyrus
  2. Postcentral gyrus
  3. Precentral gyrus Correct answer.
  4. Superior temporal gyrus

Explanation

The primary motor cortex corresponds to Brodmann area 4 in the precentral gyrus of the frontal lobe, where the corticospinal tract originates. It is somatotopically organized as the motor homunculus. The postcentral gyrus houses primary somatosensory cortex.

Question 4Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Which neurotransmitter is deficient in the striatum in Parkinson disease?

  1. GABA
  2. Dopamine Correct answer.
  3. Acetylcholine
  4. Glutamate

Explanation

Degeneration of dopaminergic neurons in the substantia nigra pars compacta reduces dopamine delivery to the striatum, producing the cardinal motor features of Parkinson disease. Dopamine normally facilitates the direct pathway and inhibits the indirect pathway. Acetylcholine is relatively overactive rather than deficient.

Question 5Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Which cranial nerve carries taste from the posterior third of the tongue?

  1. Trigeminal nerve
  2. Facial nerve
  3. Hypoglossal nerve
  4. Glossopharyngeal nerve Correct answer.

Explanation

The glossopharyngeal nerve supplies special visceral afferents to the posterior third of the tongue through its lingual branches. The facial nerve carries taste from the anterior two thirds via the chorda tympani. The hypoglossal nerve is purely motor.

Question 6Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Which fiber type is the primary carrier of sharp, well-localized pain?

  1. C fibers
  2. A-beta fibers
  3. A-delta fibers Correct answer.
  4. A-alpha fibers

Explanation

A-delta fibers are thinly myelinated, conduct rapidly, and mediate first pain, which is sharp and well localized. C fibers are unmyelinated, conduct slowly, and produce dull, poorly localized second pain. A-alpha and A-beta fibers carry proprioception and touch.

Question 7Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

A patient develops a left homonymous hemianopia with macular sparing after a right posterior cerebral artery infarct. Which structure is most likely spared?

  1. Left lateral geniculate body
  2. Optic chiasm
  3. Right occipital pole Correct answer.
  4. Right optic radiation

Explanation

The occipital pole receives dual blood supply from the posterior and middle cerebral arteries, so an occipital infarct often spares the macular representation at the pole. This produces homonymous hemianopia with macular sparing. The optic chiasm and lateral geniculate body are not supplied by the posterior cerebral artery in a way that explains this pattern.

Question 8Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Occlusion of the artery of Adamkiewicz most likely produces which neurologic deficit?

  1. Brown-Séquard syndrome
  2. Anterior spinal artery syndrome with paraplegia and preserved proprioception Correct answer.
  3. Posterior column loss with preserved motor function
  4. Cervical cord infarction with quadriparesis

Explanation

The artery of Adamkiewicz is the major radiculomedullary feeder to the lower thoracic and lumbar cord, and its occlusion causes anterior spinal artery territory infarction. This yields paraplegia, spinothalamic sensory loss, and sphincter dysfunction with relative preservation of dorsal column proprioception. The posterior columns are supplied by paired posterior spinal arteries.

Question 9Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Which finding best distinguishes an upper motor neuron lesion from a lower motor neuron lesion?

  1. Muscle fasciculations
  2. Presence of Babinski sign Correct answer.
  3. Marked muscle atrophy
  4. Areflexia

Explanation

An extensor plantar response reflects loss of corticospinal inhibition and is a hallmark of upper motor neuron lesions. Lower motor neuron lesions instead produce atrophy, fasciculations, hypotonia, and areflexia. The other listed features point toward lower motor neuron or anterior horn cell disease.

Question 10Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

A patient has a right-sided cerebellar hemisphere lesion. Which sign is most expected?

  1. Truncal ataxia with wide-based gait
  2. Bilateral resting tremor
  3. Right-sided dysmetria on finger-to-nose testing Correct answer.
  4. Left-sided intention tremor

Explanation

Cerebellar hemispheres control the ipsilateral limbs, so a right hemisphere lesion produces right-sided dysmetria, dysdiadochokinesia, and intention tremor. Truncal ataxia instead points to vermal or midline involvement. Resting tremor suggests basal ganglia disease.

Question 11Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

In the basal ganglia circuit, loss of dopaminergic input to the striatum leads to which net change?

  1. Increased excitation of the internal globus pallidus via the direct pathway
  2. Reduced activity of the subthalamic nucleus
  3. Decreased GABAergic output from the internal globus pallidus
  4. Increased inhibition of the external globus pallidus via the indirect pathway Correct answer.

Explanation

Dopamine normally inhibits the indirect pathway through D2 receptors, so its loss disinhibits the external globus pallidus and increases its inhibition of the subthalamic nucleus. This ultimately increases subthalamic drive to the internal globus pallidus and enhances thalamic inhibition. The net result is hypokinesia and rigidity.

Question 12Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Which statement about the blood-brain barrier is correct?

  1. It is absent in the area postrema. Correct answer.
  2. It is formed by fenestrated capillary endothelium.
  3. It is composed mainly of astrocytes with tight junctions.
  4. It permits free passage of large polar molecules.

Explanation

The circumventricular organs, including the area postrema, median eminence, and organum vasculosum of the lamina terminalis, lack a complete blood-brain barrier so they can sample blood or secrete peptides. Barrier properties depend on tight junctions between capillary endothelial cells. Astrocytes induce but do not form the barrier.

Question 13Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

A 60-year-old man develops sudden-onset severe headache with a third nerve palsy. Imaging shows blood in the subarachnoid space. Which pathologic process most likely underlies this event?

  1. Cavernous malformation
  2. Amyloid angiopathy
  3. Hypertensive hemorrhage in the putamen
  4. Rupture of a saccular berry aneurysm Correct answer.

Explanation

Sudden severe headache with subarachnoid blood and an isolated third nerve palsy points to a ruptured aneurysm at the junction of the internal carotid and posterior communicating arteries. Berry aneurysms arise at branch points of the circle of Willis. Amyloid angiopathy and hypertensive hemorrhage cause intraparenchymal rather than subarachnoid bleeding.

Question 14Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Which histologic feature is characteristic of a glioblastoma?

  1. Psammoma bodies
  2. Pseudopalisading necrosis and microvascular proliferation Correct answer.
  3. Rosenthal fibers
  4. Antoni A and B areas

Explanation

Glioblastoma, a grade 4 astrocytoma, shows pseudopalisading necrosis and microvascular proliferation, which define its high-grade behavior. Rosenthal fibers characterize pilocytic astrocytoma. Psammoma bodies and Antoni patterns belong to meningioma and schwannoma respectively.

Question 15Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

A patient with a frontal lobe tumor shows grasp reflex and inappropriate jocularity. Which region is most likely involved?

  1. Orbitofrontal cortex Correct answer.
  2. Dorsolateral prefrontal cortex
  3. Broca area
  4. Supplementary motor area

Explanation

Orbitofrontal damage releases primitive reflexes such as grasp and suck and produces disinhibited, socially inappropriate behavior. Dorsolateral prefrontal lesions instead impair working memory and planning. Broca area lesions cause nonfluent aphasia.

Question 16Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

A drug that blocks voltage-gated sodium channels in their inactivated state is best illustrated by which agent?

  1. Baclofen
  2. Levodopa
  3. Phenytoin Correct answer.
  4. Ethosuximide

Explanation

Phenytoin binds the inactivated state of voltage-gated sodium channels and prolongs the refractory period, limiting high-frequency repetitive firing. This use-dependent block underlies its antiepileptic action. Ethosuximide acts on thalamic T-type calcium channels, and baclofen is a GABA-B agonist.

Question 17Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

A patient develops hyperthermia, rigidity, and altered consciousness after starting a new antipsychotic. Which mechanism best explains this syndrome?

  1. Central dopamine blockade Correct answer.
  2. GABA-A receptor antagonism
  3. Acetylcholinesterase inhibition
  4. Excess serotonin release

Explanation

Neuroleptic malignant syndrome results from central dopamine D2 receptor blockade, producing rigidity, hyperthermia, autonomic instability, and altered mental status. It is treated by stopping the drug and giving dantrolene or bromocriptine. Serotonin excess instead causes the serotonin syndrome with clonus and hyperreflexia.

Question 18Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Which thalamic nucleus relays auditory information to the cortex?

  1. Ventral posterolateral nucleus
  2. Pulvinar
  3. Medial geniculate body Correct answer.
  4. Lateral geniculate body

Explanation

The medial geniculate body is the auditory relay of the thalamus, projecting to the primary auditory cortex in the superior temporal gyrus. The lateral geniculate body relays vision. The ventral posterolateral nucleus relays somatic sensation from the body.

Question 19Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

Bilateral damage to the medial temporal lobes, including the hippocampi, most likely produces which deficit?

  1. Global aphasia
  2. Inability to form new declarative memories Correct answer.
  3. Contralateral hemianesthesia
  4. Loss of procedural motor learning

Explanation

The hippocampus and adjacent medial temporal structures are required for consolidating new declarative memories, so bilateral damage causes anterograde amnesia with relative preservation of remote memory. Procedural learning depends on the basal ganglia and cerebellum. Aphasia and hemianesthesia localize elsewhere.

Question 20Basic Neurosciences (neuroanatomy, neurophysiology, neuropathology, neuropharmacology)

In the dorsal column-medial lemniscus pathway, second-order neurons decussate where?

  1. In the thalamic internal medullary lamina
  2. In the midbrain tectum
  3. In the medulla as internal arcuate fibers Correct answer.
  4. At the anterior white commissure of the spinal cord

Explanation

First-order dorsal root ganglion fibers ascend ipsilaterally in the dorsal columns to synapse in the nucleus gracilis and cuneatus. Second-order axons then cross the midline in the medulla as internal arcuate fibers to form the medial lemniscus. The spinothalamic pathway instead crosses in the spinal cord.

Question 21Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A 24-year-old man is brought to the emergency department after a high-speed road traffic collision. He is drowsy with a Glasgow Coma Scale score of 12. Which imaging investigation is the first-line study to exclude an acute intracranial haematoma?

  1. Digital subtraction cerebral angiography
  2. MRI of the brain with gadolinium
  3. Non-contrast CT of the head Correct answer.
  4. Radionuclide brain scan

Explanation

Non-contrast CT is the initial investigation in acute head trauma because it is fast, widely available, and detects acute extradural, subdural, and intracerebral haemorrhage as well as skull fractures. MRI takes longer and is impractical in an unstable trauma patient, while angiography and radionuclide imaging have no role in first-line trauma assessment.

Question 22Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

On a CT scan, which appearance most reliably distinguishes an extradural haematoma from an acute subdural haematoma?

  1. Biconvex shape with limitation at cranial sutures Correct answer.
  2. Hyperdensity relative to brain tissue
  3. Crescentic shape crossing suture lines
  4. Presence of surrounding cerebral oedema

Explanation

An extradural haematoma arises between the skull and dura and is bounded by cranial sutures where the dura is tightly adherent, producing a biconvex lens shape. A subdural haematoma lies between dura and arachnoid, spreads freely, and appears crescentic across suture lines. Both are typically hyperdense when acute, so density alone does not separate them.

Question 23Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A 55-year-old woman presents with a sudden severe headache. Non-contrast CT is normal but lumbar puncture shows uniformly blood-stained cerebrospinal fluid in all tubes. Which investigation is most appropriate to identify the source of suspected subarachnoid haemorrhage?

  1. Magnetic resonance spectroscopy
  2. CT angiography of the cerebral circulation Correct answer.
  3. Repeat non-contrast CT after 24 hours
  4. Transcranial Doppler ultrasonography

Explanation

When subarachnoid haemorrhage is suspected and CT is negative, CT angiography is the appropriate next step to detect an aneurysm or other vascular source. It is rapid and non-invasive, and can be followed by digital subtraction angiography if further detail is needed. Spectroscopy and Doppler do not demonstrate the bleeding source.

Question 24Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A patient with a suspected pituitary macroadenoma is referred for MRI. Which finding on MRI best characterises the lesion and its relationship to adjacent structures?

  1. A ring-enhancing cystic lesion in the cerebellar hemisphere
  2. A sellar mass that enhances homogeneously with gadolinium and displaces the optic chiasm Correct answer.
  3. Bilateral hippocampal atrophy with temporal horn dilatation
  4. Diffuse cortical thickening with leptomeningeal enhancement

Explanation

Pituitary macroadenomas arise in the sella, often enlarge it, and typically show homogeneous enhancement, with suprasellar extension compressing the optic chiasm. MRI with gadolinium is the study of choice for defining this relationship before surgery. The other described patterns correspond to unrelated pathologies in different compartments.

Question 25Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

Which MRI sequence is most sensitive for detecting acute infarction in the first few hours after onset of ischaemic stroke?

  1. T2-weighted imaging
  2. T1-weighted imaging
  3. Gradient echo imaging
  4. Diffusion-weighted imaging Correct answer.

Explanation

Diffusion-weighted imaging detects restricted water diffusion caused by cytotoxic oedema within minutes of ischaemia, making it the most sensitive sequence in hyperacute stroke. T1 and T2 changes appear much later, and gradient echo is used to detect haemorrhage rather than early infarction.

Question 26Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A 30-year-old man has a first generalised tonic-clonic seizure. He is neurologically intact and his CT is normal. Which investigation is the most appropriate next step in the diagnostic work-up?

  1. Electroencephalography Correct answer.
  2. Magnetic resonance spectroscopy
  3. Positron emission tomography
  4. Single photon emission computed tomography

Explanation

Electroencephalography is the standard next investigation after a first seizure with a normal CT, because it can identify epileptiform discharges or focal slowing that support a diagnosis of epilepsy and guide treatment. Functional imaging such as PET or SPECT is reserved for selected cases, usually presurgical evaluation of refractory epilepsy.

Question 27Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

Which electroencephalographic pattern is most characteristic of a generalised absence seizure?

  1. Diffuse polymorphic delta slowing
  2. Burst suppression with flat intervals
  3. Three-hertz generalised spike-and-wave discharges Correct answer.
  4. Periodic lateralised epileptiform discharges

Explanation

Absence seizures are associated with generalised, bilaterally synchronous three-hertz spike-and-wave discharges that begin and end abruptly, often activated by hyperventilation. Periodic lateralised discharges, polymorphic delta slowing, and burst suppression indicate other processes such as focal structural disease, encephalopathy, or severe cerebral dysfunction.

Question 28Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A 40-year-old woman has progressive sensorineural hearing loss and a small intracanalicular mass on contrast MRI. Which finding most supports a vestibular schwannoma rather than a meningioma at the internal auditory canal?

  1. Bilateral involvement of the cerebral convexities
  2. Concentric enlargement of the internal auditory canal with an ice-cream-cone shape Correct answer.
  3. Broad dural base with a dural tail
  4. Marked surrounding vasogenic oedema

Explanation

Vestibular schwannomas arise within the internal auditory canal and enlarge it, producing a characteristic ice-cream-cone appearance as the tumour extends into the cerebellopontine angle. Meningiomas typically have a broad dural base with a dural tail and tend to widen rather than constrict the canal. Bilateral lesions should raise suspicion of neurofibromatosis type 2.

Question 29Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

Which cerebrospinal fluid finding is most consistent with an intracranial pressure waveform showing plateau waves during continuous monitoring?

  1. A mean pressure persistently below 5 mmHg
  2. A completely flat waveform with no pulsations
  3. Sustained elevations of intracranial pressure of 20 to 50 mmHg lasting several minutes Correct answer.
  4. Transient pressure spikes lasting less than one second

Explanation

Plateau or Lundberg A waves are sustained rises in intracranial pressure, typically to 20 to 50 mmHg, lasting several minutes before returning to baseline. They indicate critically reduced intracranial compliance and imminent risk of herniation. Brief sub-second spikes and low or flat traces do not represent plateau waves.

Question 30Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A comatose patient with a severe traumatic brain injury is being monitored. At what sustained intracranial pressure threshold, in the absence of other clinical signs, is treatment usually initiated according to standard neurocritical care practice?

  1. 10 mmHg
  2. 55 mmHg
  3. 22 mmHg Correct answer.
  4. 40 mmHg

Explanation

Current neurocritical care guidance treats sustained intracranial pressure above approximately 22 mmHg, because pressures above this level are associated with worse outcome after severe traumatic brain injury. Treatment combines cerebrospinal fluid drainage, sedation, osmotherapy, and attention to cerebral perfusion pressure.

Question 31Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A patient with a suspected cervical spine injury is being assessed. Which imaging modality is most appropriate to evaluate ligamentous injury and spinal cord contusion when plain radiographs are normal but clinical suspicion persists?

  1. MRI of the cervical spine Correct answer.
  2. Plain flexion-extension radiographs under sedation
  3. Non-contrast CT of the cervical spine
  4. Radionuclide bone scan

Explanation

MRI is the modality of choice for ligamentous disruption, disc injury, and spinal cord contusion because it demonstrates soft tissue and cord signal change directly. CT is excellent for bone but does not show ligamentous or cord injury. Flexion-extension views under sedation risk neurological deterioration in an unstable spine.

Question 32Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

Which somatosensory evoked potential finding during scoliosis surgery most strongly warns of impending spinal cord injury?

  1. A persistent increase in latency of more than 10 percent with preserved amplitude
  2. A stable waveform throughout the procedure
  3. A gradual increase in amplitude with stable latency
  4. A reduction in amplitude of more than 50 percent or a latency increase of more than 10 percent Correct answer.

Explanation

Intraoperative somatosensory evoked potentials are monitored to detect cord compromise; a fall in amplitude of more than 50 percent or a latency increase of more than 10 percent is the accepted warning criterion. Such changes prompt the surgeon to check instrumentation and correct hypotension or malposition. Stable or improved signals are reassuring.

Question 33Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A patient with a suspected cerebral arteriovenous malformation is being evaluated. Which angiographic feature best characterises the lesion?

  1. A uniform capillary blush without enlarged vessels
  2. A focal area of restricted diffusion without vascular abnormality
  3. An early draining vein with a nidus supplied by enlarged feeding arteries Correct answer.
  4. A ring-enhancing lesion with central necrosis

Explanation

Arteriovenous malformations consist of a nidus of abnormal vessels fed by enlarged arteries and drained by early-filling veins, without an intervening capillary bed. Digital subtraction angiography remains the reference standard for defining this angioarchitecture before treatment. The other options describe unrelated findings.

Question 34Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

Which computed tomography finding is the earliest reliable sign of middle cerebral artery infarction?

  1. Calcification of the basal ganglia
  2. Loss of the insular ribbon and cortical sulcal effacement Correct answer.
  3. Well-defined hypodensity of the entire territory
  4. Ex vacuo ventricular dilatation

Explanation

Early ischaemic change on CT includes loss of the insular ribbon, cortical sulcal effacement, and subtle hypodensity, reflecting cytotoxic oedema before infarction becomes fully demarcated. Well-defined territorial hypodensity appears later, and ventricular dilatation from ex vacuo change develops over months. Basal ganglia calcification is an incidental finding.

Question 35Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A patient is undergoing a lumbar puncture. Which finding on cerebrospinal fluid analysis most strongly suggests bacterial meningitis?

  1. Predominantly lymphocytic pleocytosis with normal glucose
  2. Neutrophilic pleocytosis with low glucose and high protein Correct answer.
  3. Normal cell count with normal protein and glucose
  4. Xanthochromia with normal cell count

Explanation

Bacterial meningitis typically produces a neutrophilic pleocytosis with low cerebrospinal fluid glucose and elevated protein. Viral meningitis more often shows a lymphocytic picture with normal glucose, while xanthochromia indicates subarachnoid haemorrhage rather than infection. These patterns guide empirical treatment while cultures are pending.

Question 36Neuroimaging and Diagnostic Investigations (CT, MRI, angiography, EEG, evoked potentials, ICP monitoring)

A 65-year-old man with known prostate carcinoma develops progressive back pain and leg weakness. Which imaging strategy best evaluates suspected spinal metastatic disease with cord compression?

  1. MRI of the whole spine with contrast Correct answer.
  2. Plain radiographs of the lumbar spine only
  3. Ultrasound of the paraspinal region
  4. A single CT slice through the painful level

Explanation

MRI of the whole spine with contrast is the investigation of choice for suspected metastatic cord compression because it images the entire neuraxis, showing multifocal disease, epidural extension, and cord signal change. Plain films and limited CT may miss other levels and do not assess the cord. Ultrasound cannot penetrate bone.

Question 37Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 24-year-old man is brought to the emergency department after a road traffic collision. His Glasgow Coma Scale score is E1 V2 M4. What is his total GCS score and severity classification?

  1. 6, moderate head injury
  2. 7, severe head injury
  3. 7, moderate head injury
  4. 6, severe head injury Correct answer.

Explanation

The Glasgow Coma Scale sums eye, verbal and motor scores; here 1 + 2 + 4 = 7. A total of 8 or less defines severe head injury, 9-12 moderate, and 13-15 mild. Therefore a score of 7 is a severe head injury.

Question 38Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

Which finding on initial CT of a head-injured patient most strongly indicates the need for urgent neurosurgical referral?

  1. A small wedge-shaped hyperdensity in the frontal white matter
  2. A thin rim of subdural blood without mass effect
  3. A biconvex hyperdense collection with midline shift Correct answer.
  4. Diffuse cerebral swelling with preserved basal cisterns

Explanation

A biconvex (lens-shaped) hyperdense collection represents an extradural haematoma, which expands rapidly and can cause herniation, so it requires urgent neurosurgical assessment. Its association with midline shift further mandates decompression. The other listed findings are either minor or managed according to clinical trajectory.

Question 39Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A patient with a suspected cervical spine injury is being managed in the prehospital setting. Which manoeuvre is most appropriate for opening the airway while protecting the cervical spine?

  1. Jaw thrust with manual in-line stabilisation Correct answer.
  2. Insertion of an oropharyngeal airway after neck extension
  3. Hyperextension of the neck over the edge of the trolley
  4. Head-tilt chin-lift with a folded towel under the occiput

Explanation

In suspected cervical injury the jaw thrust with manual in-line stabilisation opens the airway without extending the neck, minimising the risk of secondary cord injury. Head-tilt chin-lift and neck hyperextension are avoided because they move the unstable segment.

Question 40Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

Which clinical feature best distinguishes a complete spinal cord injury from an incomplete one?

  1. Presence of spinal shock
  2. Presence of priapism
  3. Loss of bladder sensation
  4. Absence of sacral sparing Correct answer.

Explanation

Sacral sparing (perianal sensation, voluntary anal contraction, or preserved sacral pinprick) indicates that long tract fibres crossing the cord have survived, so the lesion is incomplete. Its absence after spinal shock has resolved supports a complete injury. Other features do not reliably differentiate completeness.

Question 41Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 30-year-old man has a stab wound to the medial arm with inability to flex the distal interphalangeal joint of the ring and little fingers. Which nerve is most likely injured?

  1. Musculocutaneous nerve
  2. Ulnar nerve Correct answer.
  3. Median nerve
  4. Radial nerve

Explanation

Flexion of the distal interphalangeal joints of the ring and little fingers is performed by flexor digitorum profundus, whose medial half is supplied by the ulnar nerve. A medial arm wound is in the ulnar nerve territory. Median nerve injury would preferentially affect the index and middle fingers.

Question 42Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A patient with a head injury develops a clear watery nasal discharge. Which test best confirms that the fluid is cerebrospinal fluid?

  1. Beta-2 transferrin assay of the fluid Correct answer.
  2. Serum electrolyte comparison
  3. Nasal swab culture
  4. Glucose oxidase strip testing of the fluid

Explanation

Beta-2 transferrin is a protein found almost exclusively in cerebrospinal fluid, making it the most specific confirmatory test for a CSF leak. Glucose testing is unreliable because nasal mucus and blood also contain glucose.

Question 43Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 45-year-old woman has a closed tibial fracture with a foot drop and numbness over the dorsum of the foot. Which nerve injury is most likely?

  1. Common peroneal nerve at the fibular neck Correct answer.
  2. Saphenous nerve at the medial knee
  3. Sural nerve at the lateral malleolus
  4. Tibial nerve in the popliteal fossa

Explanation

The common peroneal nerve winds around the fibular neck, where it is vulnerable to compression or stretch from a proximal tibial or fibular fracture. Injury produces foot drop with sensory loss over the dorsum of the foot and lateral leg.

Question 44Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 35-year-old man is admitted with a severe traumatic brain injury. Which measure is most appropriate for reducing the risk of secondary brain injury?

  1. Fluid restriction to keep the patient hypovolaemic
  2. Permissive hypercapnia to improve cerebral blood flow
  3. Maintaining mean arterial pressure to support cerebral perfusion Correct answer.
  4. Routine hyperventilation to a PaCO2 of 25 mmHg

Explanation

Secondary injury is limited by maintaining adequate cerebral perfusion pressure, which requires avoiding hypotension. Cerebral perfusion pressure equals mean arterial pressure minus intracranial pressure, so supporting mean arterial pressure is central to management.

Question 45Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 28-year-old man has a T6 fracture-dislocation with complete motor and sensory loss at T6. Which finding indicates that spinal shock has resolved?

  1. Onset of flaccid paralysis
  2. Return of the bulbocavernosus reflex Correct answer.
  3. Development of urinary retention
  4. Loss of the anal wink

Explanation

Spinal shock is a transient areflexia below the lesion, and its resolution is marked by the return of sacral reflexes such as the bulbocavernosus reflex. This usually occurs within 24-72 hours and allows reliable neurological assessment.

Question 46Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 62-year-old man has a chronic subdural haematoma measuring 12 mm with midline shift and progressive hemiparesis. What is the most appropriate management?

  1. Hypertonic saline infusion alone
  2. Observation with repeat CT in two weeks
  3. Burr-hole evacuation of the haematoma Correct answer.
  4. Antiplatelet therapy

Explanation

A chronic subdural haematoma with mass effect and progressive neurological deficit is treated by surgical evacuation, usually through a burr hole. Conservative management is reserved for small, asymptomatic collections.

Question 47Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 20-year-old man has a gunshot wound to the thigh with a partial laceration of the sciatic nerve and no vascular injury. What is the most appropriate timing for nerve repair?

  1. No repair, because sciatic injuries do not recover
  2. Immediate primary repair in the emergency department
  3. Early delayed repair after wound debridement and demarcation Correct answer.
  4. Repair only after one year of observation

Explanation

Traumatic nerve lacerations with clean, well-defined ends are best repaired after wound debridement, once the zone of injury has demarcated, usually within days to weeks. Immediate repair in a contaminated field risks infection.

Question 48Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A patient with a base of skull fracture has blood behind the tympanic membrane and cerebrospinal fluid otorrhoea. Which management step is most appropriate?

  1. Inserting a tympanostomy tube
  2. Keeping the ear clean and avoiding nose blowing Correct answer.
  3. Irrigating the ear with saline
  4. Packing the external auditory canal tightly

Explanation

Most traumatic CSF otorrhoea resolves spontaneously with conservative care, including keeping the ear clean, avoiding nose blowing, and avoiding packing or instrumentation that could introduce infection. Persistent leaks beyond several weeks may require surgical repair.

Question 49Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 40-year-old man has a C5 complete spinal cord injury. Which function is most likely to be preserved?

  1. Wrist extension
  2. Diaphragmatic breathing Correct answer.
  3. Elbow extension
  4. Finger abduction

Explanation

The phrenic nerve arises from C3-C5, so diaphragmatic breathing is largely preserved in a C5 complete injury. Elbow flexion is also preserved through the musculocutaneous nerve (C5-C6), but wrist extension requires C6-C7 and finger abduction requires T1.

Question 50Neurotrauma (head injury, spinal trauma, peripheral nerve injury)

A 55-year-old woman has a hangman fracture of C2 after a fall. Which structure is primarily disrupted in this injury?

  1. The posterior arch of C1
  2. The C2-C3 intervertebral disc only
  3. The pars interarticularis of C2 Correct answer.
  4. The odontoid process of C2

Explanation

A hangman fracture is traumatic spondylolisthesis of the axis, involving bilateral fractures through the pars interarticularis of C2. It usually results from hyperextension with axial loading.