13. What are the characteristics of fractures through the temporal bone?
Correct answer: A fracture through the temporal bone may disrupt the middle meningeal artery and/or vein as they traverse the bone and result in an extradural haemorrhage, which may not manifest immediately.
12. What are the characteristics of fractures of the petrous temporal bone?
Correct answer: Fractures through the petrous temporal bone may result in cerebrospinal fluid (CSF) otorrhoea, as CSF passes through into the external auditory meatus, either directly or via the mastoid air cells or middle ear in the presence of a…
11. What are the causes of coma?
Correct answer: (1) Central nervous system: trauma and disease (e.g. cerebrovascular accident (commonest), epilepsy, subarachnoid haemorrhage, cerebral tumour, abscess and meningitis) (2) Drugs: alcohol, carbon monoxide, barbiturates, aspirin and opiates. (3) Diabetes: hyperglycaemia and hypoglycaemia. (4) Uraemia. (5) Hepatic failure….
10. What is Battle’s sign?
Correct answer: This is bruising over the suboccipital region; it develops a day or two after injury and indicates a skull fracture of the posterior fossa.
9. What are the physical signs of a fracture of the posterior fossa of the skull?
Correct answer: (1) Bruising over the suboccipital region, which develops after a day or two (Battle’s sign). (2) Cranial nerve injuries – IX, X and XI (rare).
8. What are the physical signs of a fracture of the middle fossa of the skull?
Correct answer: (1) Orbital haematoma. (2) Bleeding from the ear. (3) Cerebrospinal fluid otorrhoea (rare). (4) Cranial nerve injuries – nerves VII and VIII.
7. What are the physical signs of a fracture of the anterior fossa of the skull?
Correct answer: (1) Nasal bleeding. (2) Orbital haematoma. (3) Cerebrospinal fluid rhinorrhoea. (4) Cranial nerve injuries – nerves I to VI.
6. What specific type of protein is found in cerebrospinal fluid?
Correct answer: Tau protein.
5. What is the difference between the composition of cerebrospinal fluid and normal nasal secretion?
Correct answer: The cerebrospinal fluid is rich in glucose and low in mucin content (and positive for tau protein), compared with the normal nasal secretion, which contains no sugar and is rich in mucin.
4. What are the clinical features of fractures involving the paranasal air sinuses?
Correct answer: Fractures extending through any of the paranasal air sinuses (frontal, ethmoidal or sphenoid) communicate with the outside and are therefore compound (open) fractures, as the overlying dura is usually breached. This external communication may manifest as a runny…
