← Back to Session

Questions Answered: 300

Final Score 76%

229
71

Questions

  • Q1. X Incorrect
  • Q2. X Incorrect
  • Q3. ✓ Correct
  • Q4. ✓ Correct
  • Q5. ✓ Correct
  • Q6. X Incorrect
  • Q7. ✓ Correct
  • Q8. ✓ Correct
  • Q9. ✓ Correct
  • Q10. ✓ Correct
  • Q11. ✓ Correct
  • Q12. X Incorrect
  • Q13. ✓ Correct
  • Q14. X Incorrect
  • Q15. ✓ Correct
  • Q16. ✓ Correct
  • Q17. ✓ Correct
  • Q18. ✓ Correct
  • Q19. ✓ Correct
  • Q20. ✓ Correct
  • Q21. ✓ Correct
  • Q22. ✓ Correct
  • Q23. ✓ Correct
  • Q24. ✓ Correct
  • Q25. ✓ Correct
  • Q26. X Incorrect
  • Q27. ✓ Correct
  • Q28. ✓ Correct
  • Q29. ✓ Correct
  • Q30. ✓ Correct
  • Q31. ✓ Correct
  • Q32. ✓ Correct
  • Q33. ✓ Correct
  • Q34. ✓ Correct
  • Q35. ✓ Correct
  • Q36. ✓ Correct
  • Q37. X Incorrect
  • Q38. ✓ Correct
  • Q39. X Incorrect
  • Q40. ✓ Correct
  • Q41. X Incorrect
  • Q42. ✓ Correct
  • Q43. ✓ Correct
  • Q44. X Incorrect
  • Q45. X Incorrect
  • Q46. X Incorrect
  • Q47. X Incorrect
  • Q48. ✓ Correct
  • Q49. X Incorrect
  • Q50. ✓ Correct
  • Q51. ✓ Correct
  • Q52. ✓ Correct
  • Q53. ✓ Correct
  • Q54. X Incorrect
  • Q55. X Incorrect
  • Q56. X Incorrect
  • Q57. X Incorrect
  • Q58. ✓ Correct
  • Q59. ✓ Correct
  • Q60. ✓ Correct
  • Q61. ✓ Correct
  • Q62. ✓ Correct
  • Q63. X Incorrect
  • Q64. ✓ Correct
  • Q65. ✓ Correct
  • Q66. X Incorrect
  • Q67. ✓ Correct
  • Q68. ✓ Correct
  • Q69. ✓ Correct
  • Q70. ✓ Correct
  • Q71. ✓ Correct
  • Q72. ✓ Correct
  • Q73. ✓ Correct
  • Q74. ✓ Correct
  • Q75. X Incorrect
  • Q76. ✓ Correct
  • Q77. ✓ Correct
  • Q78. ✓ Correct
  • Q79. ✓ Correct
  • Q80. X Incorrect
  • Q81. ✓ Correct
  • Q82. ✓ Correct
  • Q83. ✓ Correct
  • Q84. ✓ Correct
  • Q85. X Incorrect
  • Q86. ✓ Correct
  • Q87. ✓ Correct
  • Q88. ✓ Correct
  • Q89. ✓ Correct
  • Q90. ✓ Correct
  • Q91. ✓ Correct
  • Q92. ✓ Correct
  • Q93. ✓ Correct
  • Q94. X Incorrect
  • Q95. ✓ Correct
  • Q96. X Incorrect
  • Q97. ✓ Correct
  • Q98. X Incorrect
  • Q99. X Incorrect
  • Q100. ✓ Correct
  • Q101. ✓ Correct
  • Q102. ✓ Correct
  • Q103. ✓ Correct
  • Q104. ✓ Correct
  • Q105. ✓ Correct
  • Q106. ✓ Correct
  • Q107. ✓ Correct
  • Q108. ✓ Correct
  • Q109. ✓ Correct
  • Q110. X Incorrect
  • Q111. ✓ Correct
  • Q112. ✓ Correct
  • Q113. ✓ Correct
  • Q114. X Incorrect
  • Q115. X Incorrect
  • Q116. ✓ Correct
  • Q117. X Incorrect
  • Q118. X Incorrect
  • Q119. ✓ Correct
  • Q120. ✓ Correct
  • Q121. ✓ Correct
  • Q122. ✓ Correct
  • Q123. X Incorrect
  • Q124. ✓ Correct
  • Q125. ✓ Correct
  • Q126. X Incorrect
  • Q127. X Incorrect
  • Q128. ✓ Correct
  • Q129. ✓ Correct
  • Q130. X Incorrect
  • Q131. ✓ Correct
  • Q132. ✓ Correct
  • Q133. ✓ Correct
  • Q134. ✓ Correct
  • Q135. X Incorrect
  • Q136. ✓ Correct
  • Q137. ✓ Correct
  • Q138. ✓ Correct
  • Q139. ✓ Correct
  • Q140. ✓ Correct
  • Q141. ✓ Correct
  • Q142. ✓ Correct
  • Q143. ✓ Correct
  • Q144. ✓ Correct
  • Q145. ✓ Correct
  • Q146. ✓ Correct
  • Q147. ✓ Correct
  • Q148. ✓ Correct
  • Q149. ✓ Correct
  • Q150. ✓ Correct
  • Q151. X Incorrect
  • Q152. ✓ Correct
  • Q153. X Incorrect
  • Q154. ✓ Correct
  • Q155. ✓ Correct
  • Q156. ✓ Correct
  • Q157. ✓ Correct
  • Q158. ✓ Correct
  • Q159. ✓ Correct
  • Q160. ✓ Correct
  • Q161. ✓ Correct
  • Q162. ✓ Correct
  • Q163. ✓ Correct
  • Q164. ✓ Correct
  • Q165. X Incorrect
  • Q166. ✓ Correct
  • Q167. ✓ Correct
  • Q168. ✓ Correct
  • Q169. ✓ Correct
  • Q170. ✓ Correct
  • Q171. ✓ Correct
  • Q172. ✓ Correct
  • Q173. ✓ Correct
  • Q174. ✓ Correct
  • Q175. X Incorrect
  • Q176. X Incorrect
  • Q177. ✓ Correct
  • Q178. ✓ Correct
  • Q179. ✓ Correct
  • Q180. X Incorrect
  • Q181. ✓ Correct
  • Q182. ✓ Correct
  • Q183. ✓ Correct
  • Q184. X Incorrect
  • Q185. ✓ Correct
  • Q186. ✓ Correct
  • Q187. ✓ Correct
  • Q188. X Incorrect
  • Q189. X Incorrect
  • Q190. ✓ Correct
  • Q191. ✓ Correct
  • Q192. ✓ Correct
  • Q193. ✓ Correct
  • Q194. X Incorrect
  • Q195. ✓ Correct
  • Q196. ✓ Correct
  • Q197. ✓ Correct
  • Q198. ✓ Correct
  • Q199. ✓ Correct
  • Q200. ✓ Correct
  • Q201. X Incorrect
  • Q202. X Incorrect
  • Q203. ✓ Correct
  • Q204. ✓ Correct
  • Q205. ✓ Correct
  • Q206. ✓ Correct
  • Q207. ✓ Correct
  • Q208. ✓ Correct
  • Q209. X Incorrect
  • Q210. ✓ Correct
  • Q211. ✓ Correct
  • Q212. X Incorrect
  • Q213. ✓ Correct
  • Q214. ✓ Correct
  • Q215. ✓ Correct
  • Q216. ✓ Correct
  • Q217. X Incorrect
  • Q218. ✓ Correct
  • Q219. ✓ Correct
  • Q220. X Incorrect
  • Q221. ✓ Correct
  • Q222. ✓ Correct
  • Q223. X Incorrect
  • Q224. ✓ Correct
  • Q225. X Incorrect
  • Q226. ✓ Correct
  • Q227. X Incorrect
  • Q228. ✓ Correct
  • Q229. ✓ Correct
  • Q230. ✓ Correct
  • Q231. ✓ Correct
  • Q232. ✓ Correct
  • Q233. ✓ Correct
  • Q234. ✓ Correct
  • Q235. ✓ Correct
  • Q236. ✓ Correct
  • Q237. ✓ Correct
  • Q238. X Incorrect
  • Q239. ✓ Correct
  • Q240. X Incorrect
  • Q241. ✓ Correct
  • Q242. X Incorrect
  • Q243. ✓ Correct
  • Q244. X Incorrect
  • Q245. ✓ Correct
  • Q246. ✓ Correct
  • Q247. ✓ Correct
  • Q248. ✓ Correct
  • Q249. ✓ Correct
  • Q250. ✓ Correct
  • Q251. ✓ Correct
  • Q252. X Incorrect
  • Q253. ✓ Correct
  • Q254. X Incorrect
  • Q255. X Incorrect
  • Q256. ✓ Correct
  • Q257. ✓ Correct
  • Q258. ✓ Correct
  • Q259. ✓ Correct
  • Q260. ✓ Correct
  • Q261. ✓ Correct
  • Q262. ✓ Correct
  • Q263. ✓ Correct
  • Q264. ✓ Correct
  • Q265. X Incorrect
  • Q266. X Incorrect
  • Q267. ✓ Correct
  • Q268. ✓ Correct
  • Q269. ✓ Correct
  • Q270. ✓ Correct
  • Q271. ✓ Correct
  • Q272. ✓ Correct
  • Q273. ✓ Correct
  • Q274. ✓ Correct
  • Q275. X Incorrect
  • Q276. X Incorrect
  • Q277. ✓ Correct
  • Q278. ✓ Correct
  • Q279. ✓ Correct
  • Q280. ✓ Correct
  • Q281. ✓ Correct
  • Q282. ✓ Correct
  • Q283. ✓ Correct
  • Q284. ✓ Correct
  • Q285. ✓ Correct
  • Q286. ✓ Correct
  • Q287. ✓ Correct
  • Q288. ✓ Correct
  • Q289. ✓ Correct
  • Q290. ✓ Correct
  • Q291. ✓ Correct
  • Q292. ✓ Correct
  • Q293. ✓ Correct
  • Q294. ✓ Correct
  • Q295. ✓ Correct
  • Q296. ✓ Correct
  • Q297. X Incorrect
  • Q298. X Incorrect
  • Q299. X Incorrect
  • Q300. X Incorrect

Ophthalmology

Question 212 of 300

A 35 year old female patient presents to ED complaining of diplopia. You assess the patient and an image is shown. What is the diagnosis?

Answer:

The image shows that the left eye has a fixed dilated pupil compared to the right eye. You can see from the right eye that the patient has been asked to look up but is unable to look up with her left eye. This demonstrates an oculomotor (CN III) nerve palsy. Oculomotor nerve palsy:
  • Depressed and abducted (down and out) eye at rest
  • Diplopia
  • Ptosis
  • Fixed and dilated pupil with loss of accommodation and abnormal pupillary light reflex

Cranial Nerve Palsy

Neurology / Ophthalmology

Last Updated: 18th August 2022

Cranial nerve II: Optic nerve

Cranial Nerve Optic Nerve (CN II)
Key anatomy
  • Formed from convergence of axons of neurons in ganglion layer of retina, surrounded by cranial meninges
  • Enters skull via optic canal of sphenoid bone
  • Receives blood supply from combination of anterior cerebral, ophthalmic and central retinal arteries
Function
  • Sensory: vision
  • Reflexes: afferent pathway of pupillary light reflex, afferent pathway of accomodation reflex
Assessment
  • Visual acuity (Snellen chart)
  • Colour vision (Ishihara plates)
  • Pupillary light response
  • Accomodation reflex
  • Optic disc (fundoscopy)
  • Visual fields
Clinical effects of injury
  • Ipsilateral monocular visual loss
  • Loss of colour vision
  • Abnormal pupillary light reflex
  • Visual field defect if damage to visual pathway
Causes of injury
  • Optic neuritis in multiple sclerosis
  • Optic nerve compression in orbital cellulitis, glaucoma, tumours
  • Optic nerve toxicity secondary to poisoning e.g. alcohols
  • Trauma e.g. orbital fracture, penetrating injury to eye
  • Ischaemia secondary to vascular disease

Cranial nerve III: Oculomotor nerve

Cranial Nerve Oculomotor Nerve (CN III)
Key anatomy
  • Arises from midbrain and passes through lateral aspect of cavernous sinus
  • Exits skull through superior orbital fissure
Function
  • Motor: innervates four extraocular muscles (inferior oblique, superior, inferior and medial rectus muscles), levator palpebrae superioris muscle (elevation of upper eyelid), sphincter pupillae muscle (pupillary constriction), ciliary muscle (accommodation)
  • Reflexes: efferent pathway of pupillary light reflex, efferent pathway of accomodation reflex
Assessment
  • Eye movements
  • Accommodation reflex
  • Pupillary light response
Clinical effects of injury
  • Depressed and abducted (down and out) eye at rest
  • Diplopia
  • Ptosis
  • Fixed and dilated pupil with loss of accommodation and abnormal pupillary light reflex
Causes of injury
  • Tumours
  • Aneurysms (carotid or posterior communicating)
  • Subdural or epidural haematoma
  • Trauma
  • Cavernous sinus disease
  • Diabetes mellitus

Cranial nerve IV: Trochlear nerve

Cranial Nerve Trochlear Nerve (CN IV)
Key anatomy
  • Arises from midbrain and travels through lateral aspect of cavernous sinus
  • Exits skull through superior orbital fissure
Function
  • Motor: superior oblique muscle of eye (intorsion, depression and abduction of eye)
Assessment
  • Eye movements
Clinical effects of injury
  • Weakness of downward gaze (difficulty reading/walking downstairs)
  • Vertical diplopia
  • Eye is extorted and may be elevated (patient head tilts to opposite side to compensate)
Causes of injury
  • Idiopathic
  • Trauma
  • Microvasculopathy
  • Cavernous sinus disease
  • Raised intracranial pressure

Cranial nerve VI: Abducens nerve

Cranial Nerve Abducens nerve (CN VI)
Key anatomy
  • Arises from pons and travels through cavernous sinus
  • Exits skull through superior orbital fissure
Function
  • Motor: lateral rectus muscle of eye (abducts eye)
Assessment
  • Eye movements
Clinical effects of injury
  • Convergent squint at rest (eye turned inwards) with inability to abduct eye
  • Horizontal diplopia
Causes of injury
  • Idiopathic
  • Brain tumours
  • Extradural haematoma
  • Cavernous sinus disease
  • Diabetes mellitus
  • Wernicke-Korsakoff syndrome
  • Trauma

Report A Problem

Is there something wrong with this question? Let us know and we’ll fix it as soon as possible.

Loading Form...

Close
  • Biochemistry
  • Blood Gases
  • Haematology
Biochemistry Normal Value
Sodium 135 – 145 mmol/l
Potassium 3.0 – 4.5 mmol/l
Urea 2.5 – 7.5 mmol/l
Glucose 3.5 – 5.0 mmol/l
Creatinine 35 – 135 μmol/l
Alanine Aminotransferase (ALT) 5 – 35 U/l
Gamma-glutamyl Transferase (GGT) < 65 U/l
Alkaline Phosphatase (ALP) 30 – 135 U/l
Aspartate Aminotransferase (AST) < 40 U/l
Total Protein 60 – 80 g/l
Albumin 35 – 50 g/l
Globulin 2.4 – 3.5 g/dl
Amylase < 70 U/l
Total Bilirubin 3 – 17 μmol/l
Calcium 2.1 – 2.5 mmol/l
Chloride 95 – 105 mmol/l
Phosphate 0.8 – 1.4 mmol/l
Haematology Normal Value
Haemoglobin 11.5 – 16.6 g/dl
White Blood Cells 4.0 – 11.0 x 109/l
Platelets 150 – 450 x 109/l
MCV 80 – 96 fl
MCHC 32 – 36 g/dl
Neutrophils 2.0 – 7.5 x 109/l
Lymphocytes 1.5 – 4.0 x 109/l
Monocytes 0.3 – 1.0 x 109/l
Eosinophils 0.1 – 0.5 x 109/l
Basophils < 0.2 x 109/l
Reticulocytes < 2%
Haematocrit 0.35 – 0.49
Red Cell Distribution Width 11 – 15%
Blood Gases Normal Value
pH 7.35 – 7.45
pO2 11 – 14 kPa
pCO2 4.5 – 6.0 kPa
Base Excess -2 – +2 mmol/l
Bicarbonate 24 – 30 mmol/l
Lactate < 2 mmol/l
©2017 - 2025 MRCEM Success