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Egyptian Board Neurosurgery study materials
Egyptian Board Neurosurgery study resources

Egyptian Board Neurosurgery practice questions

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Question 1Neuroanatomy, Neurophysiology and Neuropathology

Which cranial nerve provides motor innervation to the lateral rectus muscle?

  1. Trochlear nerve (CN IV)
  2. Oculomotor nerve (CN III)
  3. Facial nerve (CN VII)
  4. Abducens nerve (CN VI) Correct answer.

Explanation

The abducens nerve (CN VI) supplies somatic motor fibers to the lateral rectus, which abducts the eye. The oculomotor nerve innervates most other extraocular muscles, the trochlear supplies the superior oblique, and the facial nerve innervates muscles of facial expression rather than extraocular muscles.

Question 2Neuroanatomy, Neurophysiology and Neuropathology

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

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

Explanation

Each optic tract carries fibers from the temporal retina of the ipsilateral eye and the nasal retina of the contralateral eye, all representing the contralateral visual field. A left tract lesion therefore causes a right homonymous hemianopia, often with macular sparing if the lesion is incomplete.

Question 3Neuroanatomy, Neurophysiology and Neuropathology

The middle meningeal artery is a branch of which artery?

  1. Vertebral artery
  2. Ophthalmic artery
  3. Maxillary artery Correct answer.
  4. Posterior communicating artery

Explanation

The middle meningeal artery arises from the maxillary artery, a terminal branch of the external carotid, and enters the skull through the foramen spinosum. Its epidural course deep to the pterion explains the classic temporal epidural hematoma after trauma.

Question 4Neuroanatomy, Neurophysiology and Neuropathology

Cerebrospinal fluid is primarily produced by which structure?

  1. Pineal gland
  2. Choroid plexus Correct answer.
  3. Ependymal lining of the third ventricle only
  4. Arachnoid granulations

Explanation

The choroid plexus, located in the lateral, third, and fourth ventricles, produces most cerebrospinal fluid through active secretion and filtration. Arachnoid granulations absorb CSF rather than produce it, and ependymal cells elsewhere contribute only a minor fraction.

Question 5Neuroanatomy, Neurophysiology and Neuropathology

Which thalamic nucleus is the principal relay for conscious proprioception and discriminative touch from the body?

  1. Ventral posteromedial nucleus
  2. Ventral posterolateral nucleus Correct answer.
  3. Pulvinar
  4. Mediodorsal nucleus

Explanation

The ventral posterolateral nucleus receives the medial lemniscus and spinothalamic fibers from the contralateral body and relays them to the primary somatosensory cortex. The ventral posteromedial nucleus serves the face via the trigeminothalamic pathway.

Question 6Neuroanatomy, Neurophysiology and Neuropathology

A patient has a wrist drop with preserved elbow extension and preserved shoulder abduction. Which nerve is most likely injured?

  1. Musculocutaneous nerve
  2. Axillary nerve
  3. Posterior interosseous nerve Correct answer.
  4. Radial nerve in the spiral groove

Explanation

The posterior interosseous nerve is a deep branch of the radial nerve that supplies wrist and finger extensors after the branches to the brachioradialis and extensor carpi radialis have arisen. A lesion therefore causes finger and wrist drop with relatively spared elbow extension, distinguishing it from a lesion in the spiral groove.

Question 7Neuroanatomy, Neurophysiology and Neuropathology

Which brainstem structure contains the cell bodies of the lower motor neurons supplying the tongue?

  1. Nucleus ambiguus in the medulla
  2. Facial motor nucleus in the pons
  3. Hypoglossal nucleus in the medulla Correct answer.
  4. Oculomotor nucleus in the midbrain

Explanation

The hypoglossal nucleus lies in the dorsal medulla near the midline and gives rise to the hypoglossal nerve, which innervates all intrinsic and most extrinsic tongue muscles. A lower motor neuron lesion produces ipsilateral tongue weakness with atrophy and fasciculations.

Question 8Neuroanatomy, Neurophysiology and Neuropathology

Occlusion of the artery of Adamkiewicz most typically produces ischemia in which spinal cord territory?

  1. Sacral dorsal roots
  2. Upper cervical lateral funiculus
  3. Lower thoracic and lumbar anterior cord Correct answer.
  4. Cervical dorsal columns

Explanation

The artery of Adamkiewicz is the largest radiculomedullary feeder, usually arising between T8 and L2, and supplies the anterior spinal artery territory of the lower thoracic and lumbar cord. Its occlusion causes anterior spinal artery syndrome with paraparesis and loss of pain and temperature sensation while dorsal column function is spared.

Question 9Neuroanatomy, Neurophysiology and Neuropathology

Which of the following best describes Wallerian degeneration?

  1. Retrograde chromatolysis of the cell body as the primary event
  2. Demyelination confined to the proximal segment with axonal preservation
  3. Anterograde breakdown of the distal axon and myelin sheath after axonal transection Correct answer.
  4. Segmental remyelination by Schwann cells without axonal loss

Explanation

After an axon is severed, the portion separated from the cell body degenerates anterogradely, with myelin breakdown and macrophage-mediated clearance, followed by Schwann cell–guided regeneration. The proximal stump undergoes retrograde changes, but these are secondary and do not define the distal process.

Question 10Neuroanatomy, Neurophysiology and Neuropathology

A patient develops sudden loss of pain and temperature sensation over the contralateral body with preserved vibration and proprioception, plus ipsilateral Horner syndrome and hoarseness. The lesion is located in which region?

  1. Ventral pons
  2. Lateral medulla Correct answer.
  3. Medial medulla
  4. Internal capsule

Explanation

This constellation reflects lateral medullary (Wallenberg) syndrome from posterior inferior cerebellar artery occlusion. The spinothalamic tract, descending sympathetic fibers, and nucleus ambiguus are all located laterally, while the medial lemniscus and corticospinal tract lie medially and are spared.

Question 11Neuroanatomy, Neurophysiology and Neuropathology

Which structure is the primary output nucleus of the basal ganglia, projecting inhibitory GABAergic fibers to the thalamus?

  1. Globus pallidus externus
  2. Subthalamic nucleus
  3. Striatum
  4. Globus pallidus internus Correct answer.

Explanation

The internal segment of the globus pallidus and the substantia nigra pars reticulata are the major output nuclei, sending tonic inhibitory GABAergic projections to the ventral anterior and ventrolateral thalamic nuclei. This inhibition modulates thalamocortical motor drive.

Question 12Neuroanatomy, Neurophysiology and Neuropathology

Which finding best distinguishes upper motor neuron from lower motor neuron weakness?

  1. Fasciculations with muscle atrophy
  2. Hyperreflexia with an extensor plantar response Correct answer.
  3. Areflexia with flaccid tone
  4. Marked focal atrophy of a single muscle group

Explanation

Upper motor neuron lesions interrupt descending corticospinal and corticobulbar influence, producing spasticity, hyperreflexia, and an extensor plantar (Babinski) response. Lower motor neuron lesions instead cause flaccidity, areflexia, atrophy, and fasciculations in the affected segment.

Question 13Neuroanatomy, Neurophysiology and Neuropathology

Which neurotransmitter is released by climbing fibers into the cerebellar cortex?

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

Explanation

Climbing fibers originate in the inferior olivary nucleus and release glutamate, producing strong complex spikes in Purkinje cells. This input is important for error-based motor learning and synaptic plasticity in the cerebellum.

Question 14Neuroanatomy, Neurophysiology and Neuropathology

A patient has a homonymous hemianopia with macular sparing and normal pupillary light reflexes. The lesion most likely involves which structure?

  1. Primary visual cortex with posterior cerebral artery supply Correct answer.
  2. Optic nerve
  3. Optic tract
  4. Optic chiasm

Explanation

Macular sparing classically follows occipital infarction because the macula has dual blood supply from the posterior and middle cerebral arteries. Normal pupillary responses are expected because the pupillary light reflex fibers leave the optic tract before the lateral geniculate nucleus.

Question 15Neuroanatomy, Neurophysiology and Neuropathology

Which molecular change is most characteristic of sporadic Parkinson disease?

  1. Accumulation of alpha-synuclein in Lewy bodies Correct answer.
  2. Extracellular amyloid beta plaques
  3. Intraneuronal hyperphosphorylated tau tangles
  4. Polyglutamine expansion in the huntingtin gene

Explanation

Sporadic Parkinson disease is a synucleinopathy characterized by alpha-synuclein aggregates forming Lewy bodies and Lewy neurites, with loss of substantia nigra pars compacta dopaminergic neurons. Tau tangles and amyloid plaques define Alzheimer disease, while huntingtin expansion causes Huntington disease.

Question 16Neuroanatomy, Neurophysiology and Neuropathology

A patient cannot abduct the right eye, has right ptosis, and shows a dilated right pupil that does not react to light. Which lesion location best explains these findings?

  1. Right optic nerve
  2. Right medial longitudinal fasciculus
  3. Right cavernous sinus involving CN III Correct answer.
  4. Right trigeminal ganglion

Explanation

A right oculomotor nerve palsy combines impaired adduction and elevation, ptosis from levator weakness, and a dilated unreactive pupil from parasympathetic fiber involvement. In the cavernous sinus the pupillary fibers are particularly vulnerable, and other sinus structures may be affected concurrently.

Question 17Neuroanatomy, Neurophysiology and Neuropathology

Which finding is most consistent with a lesion of the right cerebellar hemisphere?

  1. Left-sided intention tremor and dysmetria
  2. Contralateral spastic hemiparesis with hyperreflexia
  3. Right-sided intention tremor and dysmetria Correct answer.
  4. Bilateral resting tremor with cogwheel rigidity

Explanation

Cerebellar hemispheric lesions produce ipsilateral limb ataxia because the output pathways decussate twice, returning to the same side. Intention tremor, dysmetria, and dysdiadochokinesia are typical, and hypotonia may accompany them.

Question 18Neuroanatomy, Neurophysiology and Neuropathology

Which structure forms the medial boundary of the middle cranial fossa and transmits the internal carotid artery?

  1. Foramen ovale
  2. Jugular foramen
  3. Cavernous sinus Correct answer.
  4. Internal acoustic meatus

Explanation

The cavernous sinus lies along the lateral aspect of the sphenoid body at the medial edge of the middle cranial fossa and transmits the internal carotid artery with its sympathetic plexus. The abducens nerve runs freely within the sinus, while the oculomotor, trochlear, and ophthalmic divisions run in its lateral wall.

Question 19Neuroanatomy, Neurophysiology and Neuropathology

Which cortical area is primarily responsible for Broca aphasia when damaged in the dominant hemisphere?

  1. Medial occipital lobe
  2. Inferior frontal gyrus of the dominant hemisphere Correct answer.
  3. Superior temporal gyrus of the dominant hemisphere
  4. Postcentral gyrus

Explanation

Broca area lies in the posterior inferior frontal gyrus of the dominant hemisphere and coordinates motor speech production. Damage yields nonfluent, effortful speech with relatively preserved comprehension, often with right facial weakness.

Question 20Neuroanatomy, Neurophysiology and Neuropathology

A 62-year-old develops progressive ascending flaccid paralysis with areflexia and mild sensory symptoms after a diarrheal illness. Which mechanism best explains the neuropathy?

  1. Direct viral invasion of anterior horn cells
  2. Amyloid deposition within peripheral nerve fascicles
  3. Ischemic infarction of the anterior spinal artery territory
  4. Molecular mimicry with cross-reactive antibodies against peripheral myelin gangliosides Correct answer.

Explanation

This presentation suggests Guillain-Barré syndrome, often triggered by Campylobacter jejuni infection, in which antibodies against bacterial lipooligosaccharides cross-react with gangliosides on peripheral nerves. The result is acute inflammatory demyelinating polyradiculoneuropathy with albuminocytologic dissociation in CSF.

Question 21Neurological Examination, Neuroimaging and Diagnostic Workup

A patient with a suspected acute cervical spinal cord injury is awake, alert, and has no distracting injury. Which bedside finding best supports that the cervical cord is functionally intact before imaging is reviewed?

  1. Normal perianal sensation to pinprick
  2. Normal biceps and triceps reflexes bilaterally
  3. Intact anal sphincter tone on digital examination Correct answer.
  4. Full painless active range of motion of the neck

Explanation

Sacral sparing is the key bedside indicator that the spinal cord is at least partially intact, and preserved anal sphincter tone is a reliable component of that assessment. Reflexes and neck movement reflect segmental or musculoskeletal function rather than cord integrity. Perianal pinprick alone is less reliable than tone in an acute setting.

Question 22Neurological Examination, Neuroimaging and Diagnostic Workup

During a Glasgow Coma Scale assessment, a patient opens the eyes only after a firm nail-bed pressure, localizes the painful stimulus, and speaks confused but coherent sentences. What is the total GCS score?

  1. 13
  2. 11
  3. 10
  4. 12 Correct answer.

Explanation

Eye opening to pain scores 2, localization of pain scores 5, and confused speech scores 4, giving a total of 11. The common error is scoring eye opening to pain as 3, which applies only to opening to speech. Summing 2 + 5 + 4 yields 11, not the other listed totals.

Question 23Neurological Examination, Neuroimaging and Diagnostic Workup

Which imaging modality is the first-line study for a patient with sudden thunderclap headache and a normal neurological examination, and what is the most sensitive timing for it?

  1. CT angiography of the circle of Willis, most sensitive at 72 hours
  2. Lumbar puncture, most sensitive at 12 hours after onset
  3. MRI brain with diffusion-weighted sequences, most sensitive at 24 hours
  4. Non-contrast CT head, most sensitive within the first 6 hours Correct answer.

Explanation

A non-contrast CT is the initial test for suspected subarachnoid haemorrhage and its sensitivity is highest in the first hours after onset, approaching near-complete detection within 6 hours with modern scanners. CTA and MRI are useful adjuncts but not the first-line exclusion test. Lumbar puncture is reserved for cases with a negative CT performed in an appropriate time window.

Question 24Neurological Examination, Neuroimaging and Diagnostic Workup

A patient reports a transient loss of consciousness. Which historical feature most strongly favours a syncopal rather than an epileptic cause?

  1. A postictal headache lasting hours
  2. A brief period of confusion after waking
  3. Pallor and diaphoresis before the collapse Correct answer.
  4. Limb jerking lasting several seconds during the event

Explanation

Prodromal pallor, diaphoresis, and light-headedness reflect cerebral hypoperfusion and point toward syncope. Brief myoclonic jerking can occur in syncope (convulsive syncope), so jerking alone does not establish epilepsy. Prolonged post-event confusion and prolonged postictal headache favour a seizure.

Question 25Neurological Examination, Neuroimaging and Diagnostic Workup

Which finding on fundoscopy indicates papilloedema rather than simple optic disc drusen?

  1. Spontaneous venous pulsations at the disc margin
  2. Hyperautofluorescent deposits on fundus imaging
  3. Small discs with scalloped margins
  4. Loss of venous pulsations with disc margin blurring Correct answer.

Explanation

Raised intracranial pressure abolishes spontaneous venous pulsations and produces blurred, elevated disc margins, which favours papilloedema. Drusen typically appear as small discs with scalloped margins and hyperautofluorescent deposits. Preserved spontaneous venous pulsations argue against significant intracranial hypertension.

Question 26Neurological Examination, Neuroimaging and Diagnostic Workup

A 62-year-old presents with sudden right hemiparesis and global aphasia. Non-contrast CT at 90 minutes shows no haemorrhage. Which next step best confirms a large-vessel occlusion suitable for endovascular therapy?

  1. MRI of the cervical spine
  2. Repeat non-contrast CT in 6 hours
  3. Carotid Doppler ultrasound
  4. CT perfusion or CT angiography of the head and neck Correct answer.

Explanation

CT angiography identifies large-vessel occlusion and CT perfusion helps select patients with salvageable tissue for thrombectomy. Repeat non-contrast CT delays reperfusion and does not localize the occlusion. Cervical spine MRI and carotid Doppler do not assess intracranial large vessels acutely.

Question 27Neurological Examination, Neuroimaging and Diagnostic Workup

A patient has a suspected L4 radiculopathy. Which examination finding is most consistent with this level?

  1. Reduced sensation over the dorsum of the foot with an absent knee reflex
  2. Reduced sensation over the lateral calf with an absent ankle reflex Correct answer.
  3. Reduced sensation over the great toe with a preserved ankle reflex
  4. Reduced sensation over the medial malleolus with an absent ankle reflex

Explanation

The L4 root supplies the medial malleolus and contributes to the knee reflex, while the L5 root relates to the dorsum of the foot and great toe. The S1 root supplies the lateral border of the foot and drives the ankle reflex. Reduced lateral calf sensation with an absent ankle reflex therefore points to S1, and the medial malleolus pattern points to L4.

Question 28Neurological Examination, Neuroimaging and Diagnostic Workup

A patient has a complete third nerve palsy with a fixed dilated pupil. Which imaging study is most appropriate to identify the cause?

  1. Ultrasound of the orbit
  2. CT angiography or MR angiography of the circle of Willis Correct answer.
  3. Plain radiograph of the skull
  4. MRI of the brain with gadolinium

Explanation

A pupil-involving third nerve palsy raises concern for a posterior communicating artery aneurysm, which requires urgent vascular imaging such as CTA or MRA. Gadolinium-enhanced MRI may detect other causes but does not exclude an aneurysm as reliably. Orbital ultrasound and skull radiographs are inadequate for this question.

Question 29Neurological Examination, Neuroimaging and Diagnostic Workup

In a patient with suspected normal-pressure hydrocephalus, which combination of findings best supports shunt responsiveness?

  1. Gait apraxia, urinary incontinence, and cognitive decline with ventriculomegaly out of proportion to sulcal enlargement Correct answer.
  2. Isolated cognitive decline with diffuse cortical atrophy
  3. Unilateral tremor with normal ventricular size
  4. Headache and papilloedema with slit ventricles

Explanation

The classic triad of gait disturbance, incontinence, and cognitive decline with ventriculomegaly disproportionate to atrophy supports the diagnosis and predicts better shunt response. Diffuse atrophy with isolated cognitive decline suggests a neurodegenerative cause. Papilloedema with slit ventricles and unilateral tremor with normal ventricles do not fit.

Question 30Neurological Examination, Neuroimaging and Diagnostic Workup

A patient with a suspected pituitary adenoma has a bitemporal hemianopia. Which imaging study best characterizes the lesion and its relation to the optic chiasm?

  1. MRI of the sella with thin slices and gadolinium Correct answer.
  2. Non-contrast CT of the head
  3. PET-CT of the brain
  4. Carotid Doppler ultrasound

Explanation

Dedicated pituitary MRI with thin slices and contrast best delineates a sellar mass and its compression of the optic chiasm. Non-contrast CT has poor soft-tissue resolution in the sella. Carotid Doppler and brain PET-CT do not characterize sellar pathology.

Question 31Neurological Examination, Neuroimaging and Diagnostic Workup

A patient with a known vestibular schwannoma reports progressive hearing loss. Which test best assesses the functional status of the cochlear nerve?

  1. Visual evoked potentials
  2. Pure-tone audiometry with speech discrimination Correct answer.
  3. Electromyography of the facial muscles
  4. Caloric testing

Explanation

Pure-tone audiometry with speech discrimination quantifies cochlear nerve function and guides conservative versus surgical management. Caloric testing assesses vestibular function, not hearing. Visual evoked potentials and facial EMG assess unrelated pathways.

Question 32Neurological Examination, Neuroimaging and Diagnostic Workup

A patient presents with a first generalized tonic-clonic seizure and a normal neurological examination. Which diagnostic study is most appropriate as the initial investigation?

  1. MRI brain with epilepsy protocol and routine EEG Correct answer.
  2. Nerve conduction studies
  3. CT myelography
  4. Immediate lumbar puncture

Explanation

For a first unprovoked seizure, MRI with an epilepsy protocol and routine EEG are the standard initial investigations to identify structural lesions and epileptiform activity. Lumbar puncture is reserved for suspected infection or malignancy. CT myelography and nerve conduction studies are unrelated to cortical epilepsy.

Question 33Neurological Examination, Neuroimaging and Diagnostic Workup

A patient has a suspected spontaneous intracranial hypotension. Which MRI finding most strongly supports the diagnosis?

  1. Enlarged ventricles with periventricular oedema
  2. Hyperintense signal in the basal ganglia
  3. Multiple ring-enhancing lesions
  4. Diffuse pachymeningeal enhancement with sagging of the brainstem Correct answer.

Explanation

Spontaneous intracranial hypotension typically produces diffuse pachymeningeal enhancement, brainstem sagging, and subdural collections on MRI. Enlarged ventricles with periventricular oedema suggests hydrocephalus or interstitial oedema. Ring-enhancing lesions and basal ganglia signal change point to infection, tumour, or metabolic disease.

Question 34Neurological Examination, Neuroimaging and Diagnostic Workup

A patient has a suspected brachial plexus injury. Which test best localizes a preganglionic versus postganglionic lesion?

  1. Needle electromyography with sensory nerve action potentials Correct answer.
  2. MRI of the cervical spine with gadolinium
  3. Plain radiograph of the shoulder
  4. Ultrasound of the rotator cuff

Explanation

Needle EMG combined with sensory nerve action potential testing distinguishes preganglionic root avulsion from postganglionic plexus injury, because sensory fibres remain intact peripherally in preganglionic lesions. MRI of the cervical spine may show root avulsion but is less reliable alone. Shoulder radiographs and rotator cuff ultrasound do not localize plexus lesions.

Question 35Neurological Examination, Neuroimaging and Diagnostic Workup

A patient with a suspected dural arteriovenous fistula presents with pulsatile tinnitus and a bruit. Which imaging study is most definitive for confirming the fistula and its venous drainage pattern?

  1. CT venography
  2. MR venography
  3. Digital subtraction angiography Correct answer.
  4. Carotid Doppler ultrasound

Explanation

Digital subtraction angiography remains the reference standard for diagnosing dural arteriovenous fistulas and defining venous drainage, which guides treatment. CT venography, MR venography, and Doppler can suggest the diagnosis but cannot fully characterize the shunt or its drainage.

Question 36Neurological Examination, Neuroimaging and Diagnostic Workup

A patient with a suspected functional (psychogenic) weakness is being assessed. Which finding best supports a functional rather than an organic cause?

  1. Weakness confined to a single myotome
  2. Atrophy of the affected muscle group
  3. Fasciculations in the weak muscles
  4. Weakness that improves with distraction Correct answer.

Explanation

Weakness that normalizes with distraction, such as on examination of the contralateral limb, is a positive sign of a functional disorder. Myotomal distribution, atrophy, and fasciculations suggest lower motor neuron pathology. Diagnosing a functional disorder requires supportive positive signs, not exclusion alone.

Question 37Neurotrauma (Head and Spinal Injury)

A 28-year-old man presents after a motorcycle crash with a GCS of 14, a single episode of vomiting, and a 30-second loss of consciousness. Non-contrast CT of the brain is normal. Which factor most strongly indicates the need for observation rather than immediate discharge?

  1. The documented episode of vomiting Correct answer.
  2. The brief 30-second loss of consciousness
  3. The patient's age of 28 years
  4. The mechanism being a motorcycle crash

Explanation

In mild TBI risk stratification, post-traumatic vomiting is an independent predictor of intracranial injury and is a recognized indication for CT and for observation even when imaging is normal. Age, mechanism alone, and brief loss of consciousness without other risk factors are weaker discriminators.

Question 38Neurotrauma (Head and Spinal Injury)

Which finding on non-contrast head CT most reliably distinguishes an epidural hematoma from a subdural hematoma?

  1. Biconvex shape with limitation by cranial sutures Correct answer.
  2. Associated skull fracture
  3. Presence of a midline shift
  4. Crescentic shape crossing suture lines

Explanation

Epidural hematomas arise from arterial bleeding, usually the middle meningeal artery, and strip the dura from bone, producing a biconvex lens shape that is limited by suture lines where the dura is tightly adherent. Subdural hematomas spread freely in the subdural space, giving a crescentic shape that crosses sutures.

Question 39Neurotrauma (Head and Spinal Injury)

A patient with a severe TBI has an intraparenchymal monitor. Which cerebral perfusion pressure target is recommended by the current Brain Trauma Foundation guidelines for adults?

  1. 100 to 110 mmHg
  2. 50 to 60 mmHg
  3. 80 to 90 mmHg
  4. 60 to 70 mmHg Correct answer.

Explanation

The Brain Trauma Foundation recommends a cerebral perfusion pressure target of 60 to 70 mmHg, with avoidance of aggressive fluid and vasopressor therapy to achieve higher levels because of the risk of ARDS. Higher targets have not improved outcomes and may cause systemic complications.

Question 40Neurotrauma (Head and Spinal Injury)

Which statement best describes the role of decompressive craniectomy in severe traumatic brain injury?

  1. It replaces the need for intracranial pressure monitoring
  2. It reduces mortality in refractory intracranial hypertension but is associated with higher rates of vegetative survival Correct answer.
  3. It reliably improves functional outcome when performed within the first 6 hours
  4. It is indicated for all patients with contusions larger than 20 mL

Explanation

The DECRA and RESCUEicp trials showed that decompressive craniectomy lowers mortality in refractory raised intracranial pressure but increases the proportion of survivors in a vegetative state or with severe disability. It is therefore a rescue therapy, not a routine early intervention.

Question 41Neurotrauma (Head and Spinal Injury)

A patient with a Glasgow Coma Scale score of 8 after blunt head injury is being assessed for intubation. Which statement about airway management in this setting is most accurate?

  1. A GCS of 8 does not by itself justify intubation if the patient is breathing spontaneously
  2. Intubation should be deferred until a CT scan confirms a surgical lesion
  3. Endotracheal intubation is indicated because of impaired airway protective reflexes and the need to control ventilation Correct answer.
  4. Nasotracheal intubation is preferred to avoid neck manipulation

Explanation

A GCS of 8 or less indicates severe impairment of airway protective reflexes, and intubation is indicated to secure the airway and permit controlled ventilation and sedation. Airway control should precede imaging when the patient is unstable.

Question 42Neurotrauma (Head and Spinal Injury)

Which CT finding in a patient with traumatic brain injury most strongly predicts the development of delayed traumatic intracranial hemorrhage?

  1. A small subdural hematoma with a thickness of 2 mm
  2. A punctate subarachnoid hemorrhage in the basal cisterns
  3. A small contusion with surrounding edema Correct answer.
  4. A linear skull fracture over the temporal bone

Explanation

Contusions, especially when associated with edema, are the lesions most likely to progress and bleed further, which is why repeat imaging is advised in patients with contusions and clinical deterioration. Linear fractures and small subdural collections carry lower progression risk.

Question 43Neurotrauma (Head and Spinal Injury)

Which statement about the use of hypertonic saline versus mannitol for raised intracranial pressure after TBI is most accurate?

  1. Mannitol is preferred in hypovolemic patients because it does not cause diuresis
  2. Hypertonic saline may be preferred in patients with hypotension because it expands intravascular volume Correct answer.
  3. Hypertonic saline is ineffective when the blood-brain barrier is intact
  4. Both agents are contraindicated when serum sodium exceeds 145 mmol/L

Explanation

Hypertonic saline increases serum osmolality while expanding intravascular volume, making it attractive in hypotensive trauma patients, whereas mannitol causes an osmotic diuresis that can worsen hypovolemia and hypotension. Both agents are used for raised intracranial pressure with appropriate monitoring.

Question 44Neurotrauma (Head and Spinal Injury)

A patient with a traumatic brain injury develops diabetes insipidus with high urine output and rising serum sodium. Which finding would confirm the diagnosis?

  1. High urine osmolality with low serum osmolality
  2. Elevated urine specific gravity with oliguria
  3. Low urine osmolality with low urine specific gravity Correct answer.
  4. Low serum sodium with high urine sodium

Explanation

Diabetes insipidus results from deficient antidiuretic hormone and produces dilute urine with low osmolality and low specific gravity despite hypernatremia and high serum osmolality. The finding reflects failure of water reabsorption in the collecting ducts.

Question 45Neurotrauma (Head and Spinal Injury)

Which cervical spine clearance strategy is most appropriate for an alert, asymptomatic trauma patient with no distracting injury and a normal neurologic examination?

  1. Mandatory CT of the cervical spine in all trauma patients
  2. Application of a rigid collar for 6 weeks
  3. Clinical clearance using the NEXUS or Canadian C-Spine Rule without imaging Correct answer.
  4. Flexion-extension radiographs before any clinical assessment

Explanation

The NEXUS and Canadian C-Spine Rules allow clinical clearance without imaging in alert, stable patients without distracting injury, intoxication, or neurologic deficit. Routine imaging of every trauma patient exposes low-risk patients to unnecessary radiation.

Question 46Neurotrauma (Head and Spinal Injury)

A patient with an unstable thoracolumbar fracture has a blood pressure of 85/50 mmHg and a heart rate of 55 beats per minute. Which phenomenon best explains this presentation?

  1. Neurogenic shock from loss of sympathetic outflow Correct answer.
  2. Cardiogenic shock from myocardial contusion
  3. Hypovolemic shock from occult hemorrhage
  4. Septic shock from aspiration pneumonia

Explanation

Neurogenic shock follows acute spinal cord injury above the sympathetic outflow and produces hypotension with bradycardia due to unopposed vagal tone. Hemorrhagic shock typically presents with tachycardia, which helps distinguish the two.

Question 47Neurotrauma (Head and Spinal Injury)

Which finding on physical examination is most consistent with a complete cervical spinal cord transection at C5?

  1. Preserved biceps reflex with absent deltoid function
  2. Absent anal tone with sacral sparing
  3. Preserved sensation at C4 with absent sensation below
  4. Absent biceps reflex with preserved diaphragm function Correct answer.

Explanation

The C5 myotome supplies the biceps and deltoid, so a complete lesion at C5 abolishes the biceps reflex while the phrenic nucleus at C3-C5 may leave diaphragmatic function partially intact. Sacral sparing would indicate an incomplete lesion.

Question 48Neurotrauma (Head and Spinal Injury)

Which imaging modality is most appropriate to evaluate for a traumatic vertebral artery injury in a patient with a fracture through the transverse foramen at C2?

  1. MRI of the cervical spine without contrast
  2. Ultrasound of the carotid arteries
  3. CT angiography of the neck Correct answer.
  4. Plain lateral cervical radiograph

Explanation

Fractures involving the transverse foramen carry a high risk of vertebral artery injury, and CT angiography is the modality of choice for screening because it is fast, widely available, and sensitive for vascular injury. MRI is better for cord and ligament assessment but less reliable for acute vascular injury.

Question 49Neurotrauma (Head and Spinal Injury)

A patient with a C6 complete spinal cord injury develops sudden severe headache, sweating, and a blood pressure of 210/110 mmHg. What is the most appropriate initial step?

  1. Perform immediate tracheostomy
  2. Administer intravenous fluids to maintain perfusion
  3. Sit the patient upright and search for a noxious stimulus such as a blocked catheter Correct answer.
  4. Give intravenous atropine for bradycardia

Explanation

This presentation is autonomic dysreflexia, triggered by a noxious stimulus below the level of injury, most often bladder distension. Initial management is to sit the patient upright to reduce blood pressure and identify and remove the trigger, such as a blocked urinary catheter.

Question 50Neurotrauma (Head and Spinal Injury)

Which finding best differentiates spinal shock from neurogenic shock?

  1. Spinal shock occurs only with thoracic injuries, while neurogenic shock occurs only with cervical injuries
  2. Spinal shock refers to hypotension, while neurogenic shock refers to reflex loss
  3. Both terms describe the same hemodynamic state
  4. Spinal shock refers to transient loss of reflexes and flaccid paralysis, while neurogenic shock refers to hemodynamic instability Correct answer.

Explanation

Spinal shock is the temporary loss of all cord function below the injury, manifesting as flaccid paralysis and absent reflexes, and it resolves over days to weeks. Neurogenic shock is the hemodynamic consequence of sympathetic disruption with hypotension and bradycardia.