Neurological Infections

Question 1

Define Brain Abscess

Answer 1

A localized collection of pus in the brain parenchyma caused by infection, often bacterial or fungal.

Question 2

What are the 3 different ways Brain Abscesses spread?

Answer 2

Direct, Haematogenous, Post surgical/ Traumatic

Question 3

How are Brain Abscesses directly spread?

Answer 3

From sinusitis, otitis media, or dental infections.

Question 4

How are Brain Abscesses spread Haematogenously?

Answer 4

From a distant infection (e.g., infective endocarditis, lung abscess).

Question 5

How are Brain Abscesses spread post-surgery/traumatically?

Answer 5

Penetrating head injuries or neurosurgical procedures.

Question 6

Name 3 risk factors for developing a Brain Abscess

Answer 6

Immunosuppression (e.g., HIV, chemotherapy).
Poorly controlled diabetes.
Congenital heart disease (e.g., right-to-left shunts).

Question 7

Clinical features of Brain Abscess

Answer 7

Fever: May be absent in immunosuppressed patients.
Headache: Persistent and localized.
Neurological deficits: Focal symptoms such as hemiparesis, aphasia.
Signs of raised ICP: Vomiting, papilledema, confusion.
Seizures: Common presentation.

Question 8

Ix for Brain Abscess

Answer 8

Neuroimaging:

MRI brain with contrast: Gold standard for diagnosis.
CT brain: May show ring-enhancing lesion.
Blood cultures:

Identify causative organisms.
Lumbar puncture:

Contraindicated in raised ICP.
Other tests:

Full blood count, inflammatory markers, and testing for immunosuppression (e.g., HIV).

Question 9

Management of Brain Abscess

Answer 9

Medical:

Empirical antibiotics: Ceftriaxone + metronidazole ± vancomycin (tailored once cultures are available).
Dexamethasone: To reduce cerebral edema.
Surgical:

Aspiration or drainage: For larger abscesses (>2.5 cm) or those causing mass effect.
Monitoring:

Repeat imaging to assess response to treatment.

Question 10

The most common imaging modality for diagnosing a brain abscess is ________.

Answer 10

MRI with contrast.

Question 11

True or False: Lumbar puncture is routinely performed in patients with suspected brain abscess.

Answer 11

False. Lumbar puncture is contraindicated if there are signs of raised intracranial pressure.

Question 12

What is the initial empirical antibiotic regimen for a brain abscess?

Answer 12

Ceftriaxone + metronidazole ± vancomycin.

Question 13

Define Meningitis

Answer 13

Inflammation of the meninges surrounding the brain and spinal cord, usually caused by infection.

Question 14

Name 4 causes of Meningitis

Answer 14

Bacterial, viral, fungal, non-infectious

Question 15

Bacterial causes of Meningitis

Answer 15

Neisseria meningitidis (meningococcal).
Streptococcus pneumoniae (pneumococcal).
Listeria monocytogenes (in neonates, elderly, immunocompromised).

Question 16

Viral causes of Meningitis

Answer 16

Enteroviruses, herpes simplex virus (HSV).

Question 17

Fungal causes of Meningitis

Answer 17

Cryptococcus neoformans (common in HIV).

Question 18

Non-infectious causes of Meningitis

Answer 18

Autoimmune diseases, malignancies.

Question 19

Classic triad of Meningitis symptoms

Answer 19

Fever, neck stiffness, altered mental status.

Question 20

Other clinical features of Meningitis

Answer 20

Photophobia, headache, nausea/vomiting, seizures, and rash (purpuric rash in meningococcal meningitis).

Question 21

Ix for Meningitis

Answer 21

Lumbar Puncture. Blood Cultures + PCR testing, Imaging

Question 22

What would a lumbar puncture show for bacterial meningitis?

Answer 22

High WBC count (neutrophils), low glucose, high protein.

Question 23

What would a lumbar puncture show for viral meningitis?

Answer 23

High WBC (lymphocytes), normal glucose, normal or slightly raised protein.

Question 24

What are blood cultutes and PCR testing for when investigating Meningitis?

Answer 24

Identify causative organisms.

Question 25

What type of imaging is used in Meningitis?

Answer 25

CT/MRI: Rule out contraindications to lumbar puncture (e.g., mass effect).

Question 26

Management of Meningitis

Answer 26

Empirical antibiotics: Ceftriaxone + ampicillin (covers Listeria). Add dexamethasone to reduce inflammation. Supportive care: Fluids, seizure management, and close monitoring.

Question 27

True or False: A purpuric rash is commonly associated with pneumococcal meningitis.

Answer 27

False. It is associated with meningococcal meningitis.

Question 28

Bacterial meningitis typically shows ______ glucose and ______ protein levels in cerebrospinal fluid analysis.

Answer 28

Low glucose and high protein.

Question 29

What are the first-line antibiotics for bacterial meningitis in adults?

Answer 29

Ceftriaxone and ampicillin (to cover Listeria).

Question 30

What is the purpose of dexamethasone in bacterial meningitis treatment?

Answer 30

To reduce inflammation and the risk of long-term complications such as hearing loss.

Question 31

Define Encephalitis

Answer 31

Inflammation of the brain parenchyma, most commonly caused by viruses.

Question 32

Causes of Encephalitis

Answer 32

Viral: HSV-1 (most common), varicella-zoster virus, enteroviruses. Non-viral: Autoimmune (anti-NMDA receptor encephalitis).

Question 33

Clinical features of Encephalitis

Answer 33

Altered mental status: Confusion, agitation. Seizures. Focal neurological deficits. Fever and headache.

Question 34

Ix for Encephalitis

Answer 34

MRI brain: Key for identifying areas of inflammation. Lumbar puncture: Lymphocytic pleocytosis, normal glucose, elevated protein. PCR testing: Detects viral DNA/RNA (e.g., HSV).

Question 35

Management of Encephalitis

Answer 35

Empirical antiviral therapy: Acyclovir started promptly. Supportive care: Airway management, seizure control, fluids.

Question 36

True or False: PCR testing on cerebrospinal fluid is the gold standard for diagnosing HSV encephalitis.

Answer 36

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Question 37

Fill-in-the-blank: HSV encephalitis is often associated with abnormalities in the ________ lobe on MRI.

Answer 37

Temporal

Question 38

What is the initial treatment for suspected viral encephalitis?

Answer 38

Intravenous acyclovir.

Question 39

Name two non-infectious causes of encephalitis.

Answer 39

Autoimmune encephalitis (e.g., anti-NMDA receptor encephalitis) and paraneoplastic syndromes.

Question 40

What is Herpes Zoster Virus (shingles)?

Answer 40

Reactivation of the varicella-zoster virus (VZV), causing a painful vesicular rash in a dermatomal distribution.

Question 41

Clinical Features of HZV

Answer 41

Prodrome: Tingling, itching, or pain in the affected dermatome. Rash: Vesicular lesions along a single dermatome, unilateral. Complications: Postherpetic neuralgia, ophthalmic involvement, Ramsay Hunt syndrome.

Question 42

Managment of HZV

Answer 42

Antiviral therapy: Acyclovir, valacyclovir (within 72 hours). Analgesia: NSAIDs, gabapentin for neuralgia. Vaccination: Shingles vaccine for prevention.

Question 43

Fill-in-the-blank: The dermatomal rash seen in herpes zoster is caused by reactivation of the _______ virus.

Answer 43

Varicella-zoster virus.

Question 44

True or False: Antiviral therapy is only effective if started within 7 days of rash onset.

Answer 44

False. It is most effective within 72 hours.

Question 45

What is the most common complication of herpes zoster?

Answer 45

Postherpetic neuralgia.

Question 46

Name one vaccine used to prevent herpes zoster in adults.

Answer 46

Shingrix or Zostavax.

Question 47

What is Malaria?

Answer 47

A parasitic disease caused by Plasmodium species, transmitted by Anopheles mosquitoes.

Question 48

Causes of Malaria

Answer 48

Plasmodium falciparum (most severe). Plasmodium vivax, P. ovale, P. malariae, P. knowlesi.

Question 49

Clinical features of Malaria - prodrome

Answer 49

Fever, malaise, headache, myalgia.

Question 50

Classic triad of Malaria

Answer 50

Cyclical fever (every 48-72 hours) anaemia splenomegaly

Question 51

Severe Malaria features

Answer 51

(P. falciparum): Altered consciousness, respiratory distress, multi-organ failure.

Question 52

Ix for Malaria

Answer 52

Blood smear microscopy: Giemsa staining to identify parasite. Rapid diagnostic tests (RDTs). FBC: Anemia, thrombocytopenia.

Question 53

Management of uncomplicated Malaria

Answer 53

Artemisinin-based combination therapy (ACT). Chloroquine (if sensitive).

Question 54

Management of severe malaria

Answer 54

IV artesunate.

Question 55

Prevention of Malaria

Answer 55

Prophylaxis (e.g., atovaquone-proguanil, doxycycline). Use of insecticide-treated bed nets.

Question 56

Name the five species of Plasmodium that cause malaria in humans.

Answer 56

Plasmodium falciparum. Plasmodium vivax. Plasmodium ovale. Plasmodium malariae. Plasmodium knowlesi.

Question 57

True or False: Plasmodium falciparum is the most severe form of malaria.

Answer 57

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Question 58

Fill-in-the-blank: Malaria is transmitted by the bite of an infected ________ mosquito.

Answer 58

Anopheles.