Neurosurgery Flashcards
A 78 year old man is brought to the emergency department by the police. He is found wandering around the town centre and is confused. His family report that he is usually well apart from a simple mechanical fall 3 weeks previously from which he sustained no obvious injuries. What is the most likely underlying cause?
Acute extra dural haematoma Chronic sub dural haematoma Sub arachnoid haemorrhage Intraventricular haemorrhage Acute sub dural haematoma
The injuries that are responsible for chronic sub dural haematomas are usually fairly trivial and forgotten by the patient and their families. The onset of symptoms can be insidious with vague symptomatology and confusion predominating.
A 21 year old man is involved in a road traffic accident. After a transient period of concussion he is found to have a GCS of 15 by the paramedics. On arrival at hospital he is monitored in a side room of the emergency department. When he is next observed he is noted to have a GCS of 3 and a blown right pupil. Which of the processes below best accounts for this deterioration?
Hydrocephalus Intraventricular bleed Sub dural bleed Trans tentorial herniation Sub arachnoid haemorrhage
The presence of a blown right pupil is a sign of a third cranial nerve compression. The most likely cause is an extradural bleed. However, since this option is not listed the process of trans tentorial herniation would be the most applicable answer. Intraventricular bleeds are typically more common in premature neonates, deterioration due to hydrocephalus is more chronic.
A 28 year old man is playing tennis when he suddenly collapses and has a GCS of 4 when examined. What is the most likely cause?
Intraventricular haemorrhage Acute sub dural haematoma Sub arachnoid haemorrhage Chronic sub dural haematoma Acute extra dural haematoma
A sudden collapse and loss of consciousness is most likely to be due to a sub arachnoid haemorrhage. The other potential causes in the list usually occur as a sequel to a traumatic event, which has not occurred here
A 53 year old teacher is admitted to the vascular ward for a carotid endarterectomy. Your FY1 does a preoperative assessment and notes that there is a right homonymous hemianopia. There is no other neurology. What is the most likely cause?
Lateral medullary syndrome Middle cerebral artery infarct Anterior cerebral artery infarct Cerebellar infarct Posterior cerebral artery infarct
This patient has had a left occipital infarct, as there is only a homonymous hemianopia. If this patient had a temporal or parietal lobe infarct, there would be associated hemiparesis and higher cortical dysfunction. This is important to differentiate, as the carotid endarterectomy is inappropriate in this patient as the lesion is in the posterior cerebral artery.
A 20 year old man is admitted to the intensive care unit with an isolated severe head injury. A CT scan shows multiple intracerebral bleeds but no midline shift. He is intubated and ventilated. His pupils are dilated and react sluggishly to light. His heart rate is 50 beats/minute blood pressure 170,110 mmHg and his respiratory rate is set at 10 breaths/minute. The rising blood pressure is likely to be caused by:
Aortic and carotid baroreceptor stimulation Cortisol stimulation Renin angiotensin stimulation Sympathetic stimulation related to blood loss sympathetic stimulation related to increased intra cranial pressure
The changes seen are the result of raised ICP, its rare for head injuries to cause sufficient blood loss to affect the circulating volume.
A 25 year old cyclist is hit by a bus traveling at 30mph. He was not wearing a helmet. He arrives with a GCS of 3/15 and is intubated. A CT scan shows evidence of cerebral contusion but no localising clinical signs are present. What is the most appropriate course of action?
Burr hole decompression Decompressive craniotomy Insertion of intra cranial pressure monitoring device Administration of intravenous mannitol Parietotemporal craniotomy
This patient may well develop raised ICP over the next few days and intracranial pressure monitoring will help with management.
A 65 year old man presents with a new onset left sided hemiparesis. A CT scan of the brain is performed and this demonstrates a 4cm lesion within the right frontal lobe, it traverses the midline and displays marked central necrosis. There is extensive oedema surrounding the lesion. What is the most likely diagnosis?
Meningioma Central neurocytoma Ependymoma Oligodendroglioma Glioblastoma
Glioblastomas typically display such marked appearances and an important differential on imaging is one of cerebral abscess. A meningioma would not display such infiltrative behavior. Significant necrosis is more commonly seen with glioblastomas than with other CNS tumours.
What type of visual field defect is most likely to be noted in a patient with a craniopharyngioma?
Lower bitemporal hemianopia Upper bitemporal hemianopia Right superior quadranopia Right homonymous hemianopia Left homonymous hemianopia
Lesions at the optic chiasm classically produce a bitemporal hemianopia, however note lesions that spread up from below ie pituitary tumours, the defect is worse in the upper fields and if a lesion spreads down from above ie craniopharyngiomas, the visual defect is worse in the lower quadrants. Therefore this patient is likely to have a lower bitemporal hemianopia.
A 52 year man is admitted to the vascular ward for an amputation. The patient complains of unsteadiness. On further examination you detect right facial numbness and right sided nystagmus. There is sensory loss of the left side of the body. What is the most likely lesion?
Lateral medullary syndrome Posterior cerebral artery infarct Pontine infarct Lacunar infarct Anterior cerebral artery infarct
Lateral medullary syndrome
A combination of ipsilateral ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy with contralateral hemisensory loss indicates this diagnosis.
A 18 year old boy falls off a balcony and hits the right side of the head. He is admitted to the emergency department and has a GCS of 10. He is admitted for observation, and over the following twelve hours develops an increasing headache and confusion. A CT scan shows a crescent shaped collection of fluid between the brain and the dura with associated midline shift. What is the most likely diagnosis?
Acute sub dural haematoma Chronic sub dural haematoma Acute extra dural haematoma Chronic extra dural haematoma Sub arachnoid haemorrhage
Sub dural haematomas are the commonest intracranial mass lesions resulting from trauma. They are classified as acute, sub acute or chronic according to tempo of onset. Acute sub dural haematomas will present within 72 hours of the original injury and have hyperdense, crescent shaped appearances on CT scanning.
A 53 year old teacher is admitted to the vascular ward for a carotid endarterectomy. Your F1 does a preoperative assessment and notes that there is a right homonymous hemianopia. There is no other neurology. What is the most likely cause?
Middle cerebral artery infarct Lateral medullary syndrome Posterior cerebral artery infarct Lacunar infarct Anterior cerebral artery infarct
This patient has had a left occipital infarct, as there is only a homonymous hemianopia. If this patient had a temporal or parietal lobe infarct, there would be associated hemiparesis and higher cortical dysfunction. This is important to differentiate, as carotid endarterectomy is inappropriate in this patient since the lesion is in the posterior cerebral artery.
A male infant is born at 28 weeks gestation by emergency cesarean section. He is taken to theatre for a colostomy due to an imperforate anus. He initially seems to be progressing well. However, he begins to develop decerebrate posturing and is becoming increasingly obtunded. What is the most likely underlying problem?
Extra dural haematoma Sub arachnoid haemorrhage Acute sub dural haemorrhage Intraventricular haemorrhage Chronic sub dural haematoma
Acute neurological deterioration in premature neonates is usually due to intraventricular haemorrhage. Diagnosis is made by cranial ultrasound. Development of hydrocephalus may necessitate surgery.
A 33 year old lady develops a thunderclap headache and collapses. A CT scan shows that she has developed a subarachnoid haemorrhage. She currently has no evidence of raised intracranial pressure. Which of the following drugs should be administered?
None Atenotol Labetolol Nimodipine Mannitol
Nimodipine is a calcium channel blocker. It reduces cerebral vasospasm and improves outcomes. It is administered to most cases of sub arachnoid haemorrhage.
A 2 day old premature neonate is born by emergency cesarean section for maternal illness. The baby is noted to become floppy and unresponsive. What is the most likely cause?
Intraventricular haemorrhage Sub arachnoid haemorrhage Acute sub dural haematoma Acute extra dural haemhorrage Chronic sub dural haematoma
Neonatal deterioration in premature babies is not infrequently due to intra ventricular haemorrhage. In extreme prematurity the prognosis can be very poor.
A 65 year old male with known nasopharyngeal carcinoma presents with double vision over a few weeks. On examination he is found to have left eye proptosis and it is down and out. He reports pain on attempting to move the eye. There is an absent corneal reflex. What is the most likely diagnosis?
Posterior communicating artery aneurysm Cavernous sinus syndrome Optic nerve tumour Migraine Cerebral metastases
Cavernous sinus syndrome is most commonly caused by cavernous sinus tumours. In this case, the nasopharyngeal malignancy has locally invaded the left cavernous sinus. Diagnosis is based on signs of pain, opthalmoplegia, proptosis, trigeminal nerve lesion (opthalmic branch) and Horner’s syndrome.
