A 33-year-old man presents complaining of visual disturbance. Examination reveals a bitemporal hemianopia with predominately the upper quadrants being affected.
What is the most likely lesion?
Correct Answer C:
Bitemporal hemianopia:
An upper quadrant defect implies inferior chiasmal compression making a pituitary macroadenoma the most likely diagnosis.
Visual field defects:
The main points for the exam are:
A congruous defect simply means complete or symmetrical visual field loss and conversely an incongruous defect is incomplete or asymmetric. Please see the link for an excellent diagram.
Homonymous hemianopia:
Homonymous quadrantanopias*:
*This is very much the 'exam answer'. Actual studies suggest that the majority of quadrantanopias are caused by occipital lobe lesions. Please see the following link for more details: http://www.ncbi.nlm.nih.gov/pubmed/9109741
A 28-year-old man develops nausea and a severe headache whilst trekking in Nepal. Within the next hour he becomes ataxic and confused. A diagnosis of high altitude cerebral oedema is suspected.
Other than descent and oxygen, what is the most important treatment?
Correct Answer B: Acetazolamide is used more in the prevention of high altitude cerebral oedema.
Altitude related disorders:
There are three main types of altitude related disorders: acute mountain sickness (AMS), which may progress t high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE). All three conditions are due to the chronic hypobaric hypoxia which develops at high altitudes.
Acute mountain sickness is generally a self-limiting condition. Features of AMS start to occur above 2,500 - 3,000m, developing gradually over 6-12 hours and potentially last a number of days:
Prevention and treatment of AMS:
A minority of people above 4,000m go onto develop high altitude pulmonary oedema (HAPE) or high altitude cerebral oedema (HACE), potentially fatal conditions:
Management of HACE:
Management of HAPE:
*The relative merits of these different treatments has only been studied in small trials. All seem to work by reducing systolic pulmonary artery pressure.
A patient is referred due to the development of a third nerve palsy associated with a headache. On examination meningism is present.
Which one of the following diagnoses needs to be urgently excluded?
Correct Answer D: Painful third nerve palsy = posterior communicating artery aneurysm.
Given the combination of a headache and third nerve palsy it is important to exclude a posterior communicating artery aneurysm.
Third nerve palsy:
Features:
Causes:
*This term is usually associated with sixth nerve palsies but it may be used for a variety of neurological presentations.
Which one of the following features is most associated with frontal lobe lesions?
Brain lesions:
The following neurological disorders/features may allow localization of a brain lesion:
Gross anatomy:
Parietal lobe lesions:
Occipital lobe lesions:
Temporal lobe lesion:
Frontal lobes lesions:
More specific areas:
A 21-year-old female is seen in the first seizure clinic in the outpatient department. Both the EEG and MRI brain are normal. A decision is made not to start her on anti-epileptic medication.
What restrictions on driving should she be informed about?
Correct Answer D: Patients cannot drive for 6 months following a seizure.
DVLA: neurological disorders:
The guidelines below relate to car/motorcycle use unless specifically stated. For obvious reasons, the rules relating to drivers of heavy goods vehicles tend to be much stricter.
Specific rules:
Syncope:
*Previously rule was 12 months. It is now 6 months off driving if the license holder has undergone assessment by an appropriate specialist and no relevant abnormality has been identified on investigation, for example EEG and brain scan where indicated.
**If the tumour is a benign meningioma and there is no seizure history, license can be reconsidered 6 months after surgery if remains seizure free.
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